JP2020112803A - Transmissive liquid crystal display device - Google Patents

Abstract

To provide a high quality liquid crystal display device that excels in view angle characteristics.SOLUTION: The liquid crystal display device includes a pixel comprising a first switch 111, a second switch 112, a third switch 113 controlled at different timing than for the first and second switches, a first resistor 114, a second resistor 115, a first liquid crystal element 121, and a second liquid crystal element 122, the pixel electrode of the first liquid crystal element being electrically connected to a signal line 116 via the first switch, the pixel electrode of the first liquid crystal element being electrically connected to the pixel electrode of the second liquid crystal element via the second switch and first resistor, the pixel electrode of the second liquid crystal element being electrically connected to a Cs line 119 via the third switch and second resistor, a common electrode 118 of the first liquid crystal element being electrically connected to the common electrode of the second liquid crystal element, with a potential corresponding to the grayscale of the pixel inputted to the signal line.SELECTED DRAWING: Figure 1

Description

The present invention relates to an item, a method, or a method of producing an item. In particular, the present invention relates to a display device or a semiconductor device. Further, the present invention relates to an electronic device having the display device in a display portion.

Liquid crystal display devices are used in many electric products such as mobile phones and television receivers, and many studies have been conducted for further improvement in quality.

The liquid crystal display device is smaller and lighter than a CRT (CRT), and has the advantage of low power consumption, but has the problem of a narrow viewing angle. In recent years, much research has been done on the multi-domain method, that is, the orientation division method, in order to improve the viewing angle characteristics. For example, an MVA method (Multi-domain Vertical Al) in which a multi-domain method is combined with a VA method (Vertical Alignment; vertical alignment method).
ignition; multi-domain vertical alignment method) or PVA method (Patterned)
Vertical Alignment method).

Also, research has been conducted to improve the viewing angle by dividing one pixel into a plurality of sub-pixels and changing the alignment state of liquid crystal in each sub-pixel (Patent Document 1).

JP 2006-276582 A

However, the viewing angle characteristics cannot be said to be sufficient, and further improvement is required as a display device. Therefore, it is an object of the present invention to provide a higher quality display device having excellent viewing angle characteristics.

FIG. 84 shows an equivalent circuit diagram in one pixel of the liquid crystal display device described in Patent Document 1. Figure 8
The pixel shown by 4 has a TFT 30, a liquid crystal capacitance L1, a liquid crystal capacitance L2, a holding capacitance C1 and a holding capacitance C2, and is connected to the scanning line 3a and the data line (signal line) 6a.

Although the liquid crystal exhibits voltage holding characteristics, its holding ratio is not 100%, and there is a concern that leakage may occur due to the flow of electric charges in the liquid crystal. In the pixel shown in FIG. 84, when leakage occurs, the state of being kept at a constant potential is lost due to the charge conservation law in the portion closed by the storage capacitor C1, the storage capacitor C2, and the liquid crystal capacitor L2 in the node 11. , The potential of the node 11 is far from the potential of the initial state before the leak occurs. Therefore, the transmittance of the liquid crystal capacitance L2 is
The transmittance changes depending on the image signal written in the data line 6a, that is, the transmittance determined by the potential according to the gradation. As a result, it becomes impossible to obtain a desired gradation or the image quality deteriorates. In this way, the display quality gradually decreases with the passage of time. Therefore, the life of the product is shortened. In particular, a normally black mode display device cannot display black, resulting in a reduction in contrast.

In view of the above problems, it is an object of the present invention to realize wide viewing angle display. Another object is to provide a display device with excellent contrast. Another object is to provide a display device with excellent display quality. Alternatively, it is an object to provide a display device which is not easily affected by noise and can perform a clear display. Alternatively, it is an object to provide a display device in which display deterioration is less likely to occur. Alternatively, it is another object to provide a display device having an excellent product life.

According to one aspect of the present invention, a first switch and a second switch controlled by a first scanning line, a third switch controlled by the first scanning line and a second scanning line, and a first switch Of the first liquid crystal element, the second resistance, the first liquid crystal element, and the second liquid crystal element, and each of the first liquid crystal element and the second liquid crystal element has at least a pixel electrode. A common electrode and a liquid crystal controlled by the pixel electrode and the common electrode. The pixel electrode of the first liquid crystal element is electrically connected to the first wiring via the first switch. The pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element through the second switch and the first resistor, and the pixel electrode of the second liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element. The pixel electrode is electrically connected to the second wiring through the third switch and the second resistor, and the common electrode of the first liquid crystal element is the common electrode of the second liquid crystal element. The liquid crystal display device is electrically connected.

According to one aspect of the present invention, a first switch and a second switch controlled by a first scanning line, a third switch controlled by the first scanning line and a second scanning line, and a first switch And a second resistor, a first liquid crystal element, a second liquid crystal element, a first storage capacitor and a second storage capacitor, and the first liquid crystal element And each of the second liquid crystal elements includes at least a pixel electrode, a common electrode, and liquid crystal controlled by the pixel electrode and the common electrode,
The pixel electrode of the first liquid crystal element is electrically connected to the first wiring via the first switch, and the pixel electrode of the first liquid crystal element includes the second switch and the first switch. Is electrically connected to the pixel electrode of the second liquid crystal element via the resistance of the second liquid crystal element, and the pixel electrode of the second liquid crystal element is connected to the second wiring via the third switch and the second resistance. The pixel electrode of the first liquid crystal element is electrically connected to the second wiring via the first storage capacitor, and the pixel electrode of the second liquid crystal element is It is electrically connected to the second wiring via the second storage capacitor, and the common electrode of the first liquid crystal element is electrically connected to the common electrode of the second liquid crystal element. A characteristic liquid crystal display device.

According to one aspect of the present invention, a first switch controlled by a third scan line, a second switch controlled by the first scan line, and a control by the first scan line and the second scan line are provided. A third switch, a first resistor, a second resistor, a first liquid crystal element, and a second liquid crystal element, and the first liquid crystal element and the second liquid crystal element. Each of the liquid crystal elements has at least a pixel electrode,
The first electrode includes a common electrode and a liquid crystal controlled by the pixel electrode and the common electrode.
The pixel electrode of the liquid crystal element is electrically connected to the first wiring through the first switch,
The pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element via the second switch and the first resistor, and the pixel electrode of the second liquid crystal element is connected. Is electrically connected to the second wiring through the third switch and the second resistor, and the common electrode of the first liquid crystal element is electrically connected to the common electrode of the second liquid crystal element. And a liquid crystal display device.

According to one aspect of the present invention, a first switch controlled by a third scan line, a second switch controlled by the first scan line, and a control by the first scan line and the second scan line are provided. A third switch, a first resistor, a second resistor, a first liquid crystal element, and a second liquid crystal element, and the first liquid crystal element and the second liquid crystal element. Each of the liquid crystal elements has at least a pixel electrode,
The first electrode includes a common electrode and a liquid crystal controlled by the pixel electrode and the common electrode.
The pixel electrode of the liquid crystal element is electrically connected to the first wiring through the first switch,
The pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element via the second switch and the first resistor, and the pixel electrode of the second liquid crystal element is connected. Is electrically connected to a second wiring via the third switch and the second resistor, and a pixel electrode of the first liquid crystal element is connected to the second storage capacitor via the first storage capacitor. Of the second liquid crystal element, the pixel electrode of the second liquid crystal element is electrically connected to the second wiring through the second storage capacitor, and the pixel electrode of the first liquid crystal element is the common electrode of the first liquid crystal element. Is a liquid crystal display device characterized by being electrically connected to a common electrode of the second liquid crystal element.

One aspect of the present invention is the liquid crystal display device according to the above structure, wherein the resistance value of the second resistor is larger than the resistance value of the first resistor.

One feature of the present invention is to provide a switch controlled by a first scan line, a first transistor, a second transistor, a first liquid crystal element, a second liquid crystal element, and a first storage capacitor. A gate electrode of the first transistor is electrically connected to the first scan line, and a gate electrode of the second transistor is the first electrode. And a transistor electrically connected to the scan line and a transistor provided in series with the transistor and having a gate electrode electrically connected to the second scan line.
Each of the first liquid crystal element and the second liquid crystal element includes at least a pixel electrode, a common electrode, and
The liquid crystal controlled by the pixel electrode and the common electrode, the pixel electrode of the first liquid crystal element is electrically connected to the first wiring via the switch, and the first liquid crystal element is formed. Is electrically connected to the pixel electrode of the second liquid crystal element via the first transistor, and the pixel electrode of the second liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element via the second transistor. Of the first liquid crystal element, the pixel electrode of the first liquid crystal element is electrically connected to the second wiring via the first storage capacitor, and the pixel electrode of the second liquid crystal element is electrically connected. Is electrically connected to the second wiring through the second storage capacitor, and the common electrode of the first liquid crystal element is
The liquid crystal display device is electrically connected to a common electrode of the second liquid crystal element.

One feature of the present invention is a first transistor, a second transistor, a third transistor, a first liquid crystal element, a second liquid crystal element, a first storage capacitor, and a second storage capacitor. And a gate electrode of the first transistor and the third transistor are electrically connected to the first scan line, and a gate electrode of the second transistor is the first electrode. Of the first liquid crystal, the transistor having a transistor electrically connected to the scan line and a transistor provided in series with the transistor and having a gate electrode electrically connected to the second scan line. Each of the element and the second liquid crystal element includes at least a pixel electrode, a common electrode, and liquid crystal controlled by the pixel electrode and the common electrode, and the pixel electrode of the first liquid crystal element is the Electrically connected to the first wiring through the transistor of 3,
The pixel electrode of the first liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element via the first transistor, and the pixel electrode of the second liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element. The pixel electrode of the first liquid crystal element is electrically connected to a second wiring via a transistor, and the pixel electrode of the first liquid crystal element is electrically connected to the second wiring via the first storage capacitor. The pixel electrode of the liquid crystal element is electrically connected to the second wiring via the second storage capacitor, and the common electrode of the first liquid crystal element is connected to the common electrode of the second liquid crystal element. The liquid crystal display device is electrically connected.

One feature of the present invention is that, in the above structure, when the channel width of the transistor is W and the channel length is L, W/L of the third transistor is higher than W/L of the first transistor or the second transistor. A liquid crystal display device characterized by being small.

Another feature of the present invention is that, in the above structure, when the channel width of the transistor is W and the channel length is L, W/L of the second transistor is larger than W/L of the first transistor. It is a liquid crystal display device.

Note that the display device of the present invention is, for example, a liquid crystal display device, a light emitting device having a light emitting element represented by an organic light emitting element (OLED) in each pixel, a DMD (Digital Micromirror).
Device), PDP (Plasma Display Panel), FED (F
An active matrix display device such as a field emission display is included in the category. It also includes a passive matrix display device.

Note that various types of switches can be used. Examples include electrical switches and mechanical switches. In other words, anything that can control the flow of current,
It is not limited to a particular one. For example, as a switch, a transistor (eg, bipolar transistor, MOS transistor, etc.), diode (eg, PN diode, P)
IN diode, Schottky diode, MIM (Metal Insulator)
Metal) diode, MIS (Metal Insulator Semiconductor)
For example, an inductor, a diode-connected transistor, or the like, a thyristor, or the like can be used. Alternatively, a logic circuit in which these are combined can be used as a switch.

An example of a mechanical switch is a digital micromirror device (DMD),
There is a switch using MEMS (micro electro mechanical system) technology. The switch has an electrode that can be mechanically moved, and movement of the electrode controls connection and disconnection to operate.

When a transistor is used as a switch, the transistor operates as a simple switch, and therefore the polarity (conductivity type) of the transistor is not particularly limited. However, in order to suppress the off-state current, it is desirable to use a transistor having a polarity with a smaller off-state current. As a transistor with low off-state current, a transistor having an LDD region, a transistor having a multi-gate structure, or the like can be given. Alternatively, when the source terminal of the transistor which operates as a switch operates in a state where the potential of the source terminal of the transistor is close to the potential of the low-potential power source (Vss, GND, 0 V, or the like), it is preferable to use an N-channel transistor. On the contrary, when the source terminal operates in a state close to the potential of the high-potential side power source (Vdd or the like), it is desirable to use the P-channel type transistor. This is because when an N-channel type transistor operates in a state where the source terminal is close to the potential of the low potential side power supply, and in a P-channel type transistor when operating in a state where the source terminal is close to the potential of the high potential side power supply, This is because it is easy to operate as a switch because the absolute value of the voltage between them can be increased. In addition, since the source follower operation is rarely performed, the output voltage is unlikely to be small.

In addition, by using both the N-channel type transistor and the P-channel type transistor, the CMOS
Type switches may be used as switches. In the case of a CMOS type switch, a current flows if either one of the P-channel transistor and the N-channel transistor becomes conductive, so that it easily functions as a switch. For example, the voltage can be appropriately output regardless of whether the voltage of the input signal to the switch is high or low. Furthermore, since the voltage amplitude value of the signal for turning the switch on and off can be reduced, power consumption can also be reduced.

When a transistor is used as the switch, the switch has an input terminal (one of a source terminal and a drain terminal), an output terminal (the other of the source terminal and the drain terminal), and a terminal for controlling conduction (a gate terminal). doing. On the other hand, when a diode is used as the switch, the switch may not have a terminal for controlling conduction. Therefore, when a diode is used as a switch rather than a transistor, wiring for controlling a terminal can be reduced.

In addition, when it is explicitly described that A and B are connected, there are cases where A and B are electrically connected and cases where A and B are functionally connected. , A and B are directly connected. Here, A and B are objects (for example, devices, elements, circuits, wirings, electrodes, terminals, conductive films, layers, etc.). Therefore, the predetermined connection relationship,
For example, it is not limited to the connection relations shown in the figures or the texts, but includes other connection relations than the connection relations shown in the figures or the texts.

For example, when A and B are electrically connected, an element (for example, a switch, a transistor, a capacitive element, an inductor, a resistance element, a diode, etc.) that enables the A and B to be electrically connected is , A and B may be arranged one or more. Alternatively, when A and B are functionally connected, a circuit (for example, a logic circuit (inverter, NAND circuit, NOR circuit, etc.), a signal conversion circuit that enables the functional connection between A and B) (DA conversion circuit, AD conversion circuit, gamma correction circuit, etc.), potential level conversion circuit (power supply circuit (step-up circuit,
Step-down circuit, etc.), level shifter circuit that changes the potential level of the signal, etc.), voltage source, current source,
Switching circuit, amplifier circuit (circuit that can increase signal amplitude or current amount, operational amplifier,
One or more differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, storage circuits, control circuits, etc.) may be arranged between A and B. Alternatively, in the case where A and B are directly connected, A and B are not sandwiched between A and B, and A and B
And may be directly connected.

In addition, when it is explicitly described that A and B are directly connected, when A and B are directly connected (that is, other elements and other circuits are provided between A and B). And A and B are electrically connected (that is, they are connected by sandwiching another element or another circuit between A and B). (If present) and.

In addition, when it is explicitly described that A and B are electrically connected, when A and B are electrically connected (that is, another element is provided between A and B). Or when A and B are functionally connected with each other (that is, when A and B are functionally connected with another circuit interposed therebetween). And the case where A and B are directly connected (that is, the case where they are connected without sandwiching another element or another circuit between A and B). In other words, the explicit description of being electrically connected is the same as the explicit description of only being connected.

Note that a display element, a display device that is a device including a display element, a light-emitting element, and a light-emitting device that is a device including a light-emitting element can have various modes and have various elements. For example, as a display element, a display device, a light emitting element, or a light emitting device, an EL element (an EL element containing an organic substance and an inorganic substance, an organic EL element, an inorganic EL element), an electron emission element, a liquid crystal element, electronic ink, an electrophoretic element, Grating light valve (GLV), plasma display (PD
P), digital micromirror device (DMD), piezoelectric ceramic display, carbon nanotube, and the like, which can be used are display media whose contrast, brightness, reflectance, transmittance, and the like change due to an electromagnetic effect. An EL display is used as a display device using an EL element, and a field emission display (FED) or a SED type flat display (SED: Surface-co) is used as a display device using an electron-emitting device.
A liquid crystal display (transmissive liquid crystal display, semi-transmissive liquid crystal display, reflective liquid crystal display, direct-view liquid crystal display, projection liquid crystal display), electronic ink, or a liquid crystal display is used as a display device using a liquid crystal element, such as an nucleation electron-emitter display. There is electronic paper as a display device using an electrophoretic element.

Note that an EL element is an element having an anode, a cathode, and an EL layer sandwiched between the anode and the cathode. The EL layer uses light emission (fluorescence) from singlet excitons, 3
Including those utilizing emission (phosphorescence) from singlet excitons and those utilizing emission (fluorescence) from singlet excitons and those utilizing emission (phosphorescence) from triplet excitons , Those formed by organic substances, those formed by inorganic substances, including those formed by organic substances and those formed by inorganic substances, polymeric materials, low molecular weight materials, polymeric materials and low molecular weight materials And the like can be used. However, it is not limited to this, and E
Various L elements can be used.

The electron-emitting device is a device that draws out electrons by concentrating a high electric field on a sharp cathode. For example, as electron-emitting devices, Spindt type, carbon nanotube (CNT) type, MIM (Metal-Insulator-Metal) type in which metal-insulator-metal is laminated, and MIS (Metal-Insulator) in which metal-insulator-semiconductor is laminated. -Semicon
inductor type, MOS type, silicon type, thin film diode type, diamond type, surface conduction emitter SCD type, ode type, diamond type, surface conduction emitter SCD type, metal-insulator-semiconductor-metal type thin film type, HEED Type, EL type, porous silicon type, surface conduction (SED) type and the like can be used. However, the present invention is not limited to this, and various electron-emitting devices can be used.

Note that the liquid crystal element is an element that controls transmission or non-transmission of light by an optical modulation action of liquid crystal, and includes a pair of electrodes and liquid crystal. Note that the optical modulation action of the liquid crystal is controlled by an electric field applied to the liquid crystal (including a horizontal electric field, a vertical electric field, or an oblique electric field). As the liquid crystal element, nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, discotic liquid crystal, thermotropic liquid crystal, lyotropic liquid crystal, lyotropic liquid crystal, low molecular weight liquid crystal, polymer liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, main chain Type liquid crystal, side chain type polymer liquid crystal, plasma addressed liquid crystal (PDLC), banana type liquid crystal, TN (Twisted)
Nematic) mode, STN (Super Twisted Nematic) mode, IPS (In-Plane-Switching) mode, FFS (Fringe)
Field Switching mode, MVA (Multi-domain Ver)
mechanical alignment) mode, PVA (Patterned Vertic)
al Alignment), ASV (Advanced Super View) mode, ASM (Axially Symmetric Aligned Micro-ce).
11) mode, OCB (Optical Compensated Birefring)
ence) mode, ECB (Electrically Controlled Bir)
fringe mode, FLC (Ferroelectric Liquid)
Crystal mode, AFLC (Anti Ferroelectric Liquid)
d Crystal mode, PDLC (Polymer Dispersed Liq)
A uid crystal mode, a guest host mode, or the like can be used. However, the present invention is not limited to this, and various liquid crystal elements can be used.

As electronic paper, ones displayed by molecules such as optical anisotropy and dye molecule orientation, those displayed by particles such as electrophoresis, particle movement, particle rotation, and phase change, one end of the film are Refers to those that are displayed by moving, those that are displayed by color development/phase change of molecules, those that are displayed by light absorption of molecules, and those that are displayed by self-light emission by combining electrons and holes. .. For example, as electronic paper, microcapsule type electrophoresis, horizontal movement type electrophoresis, vertical movement type electrophoresis, spherical twist ball, magnetic twist ball, cylindrical twist ball method, charged toner, electronic powder fluid, magnetophoretic type, magnetic thermosensitive Formula, electrowetting, light scattering (transparent white turbidity), cholesteric liquid crystal/photoconductive layer, cholesteric liquid crystal, bistable nematic liquid crystal, ferroelectric liquid crystal, dichroic dye/liquid crystal dispersion type, movable film, leuco dye extinction Color, photochromic, electrochromic, electrodeposition, flexible organic EL, etc. can be used. However, it is not limited to this,
Various electronic papers can be used. Here, by using the microcapsule type electrophoresis, it is possible to solve the drawbacks of the electrophoresis method, such as aggregation and precipitation of electrophoretic particles. The electronic powder fluid has advantages such as high-speed response, high reflectance, wide viewing angle, low power consumption, and memory property.

In a plasma display, a substrate on which electrodes are formed and a substrate on which electrodes and minute grooves are formed on the surface and a phosphor layer is formed in the grooves are opposed to each other at a narrow interval and a rare gas is sealed. Have a structure. Note that display can be performed by applying a voltage between the electrodes to generate ultraviolet rays and illuminate the phosphor. As a plasma display, DC
Type PDP or AC type PDP may be used. Here, the plasma display panel is AS
W (Address While Sustain) driving, ADS (Address Display Sep) that divides a subframe into a reset period, an address period, and a sustain period.
driven), CLEAR (Low Energy Address and R)
EDUCATION OF FALSE CONTOUR SEQUENCE) drive, AL
IS (Alternate Lighting of Surfaces) method, TER
ES (Technology of Recipe Local Sustainer) drive or the like can be used. However, the present invention is not limited to this, and various types of plasma displays can be used.

A display device requiring a light source, for example, a liquid crystal display (transmissive liquid crystal display, semi-transmissive liquid crystal display, reflective liquid crystal display, direct-view liquid crystal display, projection liquid crystal display), grating light valve (GLV) is used. As a light source for such a display device and a display device using a digital micromirror device (DMD), electroluminescence, cold cathode tubes, hot cathode tubes, LEDs, laser light sources, mercury lamps and the like can be used. However, the light source is not limited to this, and various light sources can be used.

Note that various types of transistors can be used as the transistor. Therefore,
There is no limitation on the type of transistor used. For example, a thin film transistor (TFT) having a non-single-crystal semiconductor film typified by amorphous silicon, polycrystalline silicon, microcrystalline (also referred to as semi-amorphous) silicon, or the like can be used. There are various advantages when using a TFT. For example, since it can be manufactured at a temperature lower than that of the case of single crystal silicon, it is possible to reduce the manufacturing cost or increase the size of the manufacturing apparatus. Since the manufacturing apparatus can be enlarged, it can be manufactured on a large substrate. Therefore, since a large number of display devices can be manufactured at the same time, the manufacturing cost can be reduced. Further, since the manufacturing temperature is low, a substrate having low heat resistance can be used. Therefore, the transistor can be manufactured on the transparent substrate. Then, the transmission of light in the display element can be controlled by using the transistor on the transparent substrate.
Alternatively, since the thickness of the transistor is small, part of the film included in the transistor can transmit light. Therefore, the aperture ratio can be improved.

Note that by using a catalyst (such as nickel) when manufacturing polycrystalline silicon, it is possible to further improve the crystallinity and manufacture a transistor with excellent electric characteristics. As a result, a gate driver circuit (scan line driver circuit) or a source driver circuit (signal line driver circuit)
A signal processing circuit (a signal generation circuit, a gamma correction circuit, a DA conversion circuit, etc.) can be integrally formed on the substrate.

Note that by using a catalyst (such as nickel) when manufacturing microcrystalline silicon, the crystallinity can be further improved and a transistor with favorable electric characteristics can be manufactured. At this time, the crystallinity can be improved by only performing heat treatment without irradiating the laser beam. As a result, part of the gate driver circuit (scanning line driver circuit) or the source driver circuit (analog switch or the like) can be integrally formed over the substrate. Furthermore, when laser light irradiation is not performed for crystallization, unevenness in crystallinity of silicon can be suppressed. Therefore, a beautiful image can be displayed.

However, it is possible to manufacture polycrystalline silicon or microcrystalline silicon without using a catalyst (such as nickel).

It is desirable to improve the crystallinity of silicon to polycrystal, microcrystal, or the like in the entire panel, but the invention is not limited thereto. The crystallinity of silicon may be improved only in a partial region of the panel. It is possible to selectively improve the crystallinity by selectively irradiating with laser light. For example, the laser light may be applied only to the peripheral circuit region which is a region other than the pixels. Alternatively, the laser light may be applied only to regions such as the gate driver circuit and the source driver circuit. Alternatively, the laser light may be applied only to a part (eg, analog switch) region of the source driver circuit. as a result,
The crystallization of silicon can be improved only in the region where the circuit needs to operate at high speed. Since it is not necessary to operate the pixel region at high speed, the pixel circuit can be operated without any problem even if the crystallinity is not improved. Since a region for improving crystallinity is small, a manufacturing process can be shortened, throughput can be improved, and manufacturing cost can be reduced. Further, since the number of required manufacturing apparatuses is small and the manufacturing can be performed, the manufacturing cost can be reduced.

Alternatively, the transistor can be formed using a semiconductor substrate, an SOI substrate, or the like. As a result, it is possible to manufacture a transistor with small variation in characteristics, size, shape, etc., high current supply capability, and small size. When these transistors are used, low power consumption of the circuit or high integration of the circuit can be achieved.

Alternatively, a transistor including a compound semiconductor or an oxide semiconductor such as ZnO, a-InGaZnO, SiGe, GaAs, IZO, ITO, or SnO, or a thin film transistor in which these compound semiconductors or oxide semiconductors are thinned can be used. I can. With these, the manufacturing temperature can be lowered, and for example, the transistor can be manufactured at room temperature. As a result, the transistor can be formed directly on a substrate having low heat resistance, for example, a plastic substrate or a film substrate. In addition, these compound semiconductors or oxide semiconductors,
It can be used not only for the channel part of the transistor but also for other purposes. For example, these compound semiconductors or oxide semiconductors can be used as a resistance element, a pixel electrode, and a transparent electrode. Further, since they can be formed or formed at the same time as the transistor, cost can be reduced.

Alternatively, a transistor or the like formed using an inkjet method or a printing method can be used. As a result, they can be manufactured at room temperature, at a low degree of vacuum, or on a large substrate. Further, since the manufacturing can be performed without using a mask (reticle), the layout of the transistor can be easily changed. Further, since it is not necessary to use a resist, the material cost can be reduced and the number of steps can be reduced. Further, since the film is formed only on the necessary part, the material is not wasted and the cost can be reduced as compared with the manufacturing method of etching after forming the film on the entire surface.

Alternatively, a transistor or the like including an organic semiconductor or carbon nanotube can be used. With these, a transistor can be formed over a bendable substrate.
Therefore, it can withstand shock.

Further, transistors with various structures can be used. For example, a MOS transistor, a junction transistor, a bipolar transistor, or the like can be used as the transistor. By using the MOS type transistor, the size of the transistor can be reduced. Therefore, a large number of transistors can be mounted. A large current can be passed by using a bipolar transistor. Therefore, the circuit can be operated at high speed.

Note that MOS type transistors, bipolar transistors, and the like may be mixed and formed on one substrate. As a result, low power consumption, miniaturization, high speed operation, etc. can be realized.

In addition, various transistors can be used.

Note that the transistor can be formed using various substrates. The type of substrate is not limited to a particular one. Examples of substrates on which transistors are formed include single crystal substrates, SOI substrates, glass substrates, quartz substrates, plastic substrates, paper substrates, cellophane substrates, stone substrates, wood substrates, cloth substrates (natural fibers (silk, cotton, hemp). ), synthetic fibers (nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, stainless steel substrates, substrates with stainless steel foil, etc. Can be used. Alternatively, the skin (dermis, dermis) or subcutaneous tissue of animals such as humans may be used as the substrate. Alternatively, a transistor may be formed using one substrate, and then the transistor may be transferred to another substrate and the transistor may be arranged over another substrate. Substrates on which the transistors are transferred include single crystal substrates, SOI substrates, glass substrates, quartz substrates, plastic substrates, paper substrates, cellophane substrates, stone substrates, wood substrates, cloth substrates (natural fibers (silk, cotton, hemp), Use synthetic fibers (nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, stainless steel substrates, substrates with stainless steel foil, etc. You can Alternatively, the skin of humans or other animals (skin surface, dermis)
Alternatively, subcutaneous tissue may be used as the substrate. Alternatively, a transistor may be formed using a certain substrate and the substrate may be polished to be thin. As a substrate to be polished, a single crystal substrate, SOI
Substrate, glass substrate, quartz substrate, plastic substrate, paper substrate, cellophane substrate, stone substrate,
Wood substrate, cloth substrate (including natural fiber (silk, cotton, hemp), synthetic fiber (nylon, polyurethane, polyester) or recycled fiber (acetate, cupra, rayon, recycled polyester), leather substrate, rubber substrate, stainless steel) -A still substrate, a substrate having a stainless steel foil, or the like can be used. Alternatively, the skin (dermis, dermis) or subcutaneous tissue of animals such as humans may be used as the substrate. By using these substrates, formation of transistors with good characteristics, formation of transistors with low power consumption, manufacturing of devices that are not easily broken,
It is possible to impart heat resistance, reduce the weight, or reduce the thickness.

Note that the transistor can have various structures. It is not limited to a specific configuration. For example, a multi-gate structure having two or more gate electrodes may be used. With the multi-gate structure, since the channel regions are connected in series, a plurality of transistors are connected in series. With the multi-gate structure, off current can be reduced and reliability can be improved by improving the withstand voltage of the transistor. Alternatively, due to the multi-gate structure, when operating in the saturation region, even if the drain-source voltage changes, the drain-source current does not change much and the slope of the voltage-current characteristics can be made flat. it can. By using the characteristic that the slope of the voltage/current characteristic is flat, it is possible to realize an ideal current source circuit and an active load having a very high resistance value. As a result, a differential circuit and a current mirror circuit having good characteristics can be realized. Further, a structure in which gate electrodes are arranged above and below the channel may be used. With the structure in which the gate electrodes are provided above and below the channel, the channel region is increased, so that the S value can be reduced by increasing the current value or by easily forming a depletion layer. When the gate electrodes are arranged above and below the channel, a structure in which a plurality of transistors are connected in parallel is formed.

Alternatively, the gate electrode may be arranged above the channel region, or the gate electrode may be arranged below the channel region. Alternatively, the structure may be a normal stagger structure or an inverted stagger structure, the channel region may be divided into a plurality of regions, the channel regions may be connected in parallel, or the channel regions may be connected in series. Good. Also,
The source electrode and the drain electrode may overlap with the channel region (or part thereof).
With the structure in which the source electrode and the drain electrode overlap with the channel region (or part thereof), electric charge can be prevented from being accumulated in part of the channel region and unstable operation can be prevented. Further, an LDD region may be provided. By providing the LDD region, off current can be reduced or reliability can be improved by improving the withstand voltage of the transistor. Or L
By providing the DD region, when operating in the saturation region, even if the drain-source voltage changes, the drain-source current does not change much, and the slope of the voltage-current characteristic can be made flat. it can.

Note that various types of transistors can be used for the transistor and can be formed using various substrates. Therefore, all the circuits necessary for realizing a predetermined function may be formed on the same substrate. For example, a glass substrate, a plastic substrate, a single crystal substrate, or an SOI substrate may be used for all of the circuits necessary for realizing a predetermined function, or various circuits can be used. Good. Since all the circuits required to realize a given function are formed using the same substrate, cost reduction is achieved by reducing the number of components, or reliability is improved by reducing the number of connection points with circuit components. Can be planned. Alternatively, part of the circuit necessary for achieving the predetermined function is formed over one substrate and another part of the circuit necessary for achieving the predetermined function is formed over another substrate. May be. That is, not all of the circuits required to realize a predetermined function need be formed using the same substrate. For example, part of a circuit necessary for achieving a predetermined function is formed using a transistor over a glass substrate, and another part of a circuit necessary for achieving a predetermined function is a single crystal substrate. An IC chip formed on the single crystal substrate and formed of transistors may be connected to a glass substrate by COG (Chip On Glass) and the IC chip may be arranged on the glass substrate. Alternatively, if the IC chip is TAB(T
Ape Automated Bonding) or a printed circuit board may be used to connect to the glass substrate. As described above, by forming a part of the circuit on the same substrate, it is possible to reduce the cost by reducing the number of components or improve the reliability by reducing the number of connection points with the circuit components. In addition, circuits with high driving voltage and high driving frequency consume large amounts of power. Therefore, circuits in such parts are not formed on the same substrate. Instead, for example, on a single crystal substrate. By forming a circuit in that portion and using an IC chip configured by the circuit, an increase in power consumption can be prevented.

Note that one pixel represents one element whose brightness can be controlled. Therefore, as an example, one pixel indicates one color element, and the brightness is expressed by the one color element.
Therefore, in that case, in the case of a color display device including color elements of R (red), G (green), and B (blue), the minimum unit of the image is the R pixel, the G pixel, and the B pixel. It shall consist of three pixels. The color elements are not limited to three colors, and three or more colors may be used, or colors other than RGB may be used. For example, RGBW (W is white) may be added by adding white. Also, R
One or more colors such as yellow, cyan, magenta, emerald green, and vermilion may be added to GB. Also, for example, if a color similar to at least one of RGB is
May be added to. For example, R, G, B1 and B2 may be used. Both B1 and B2 are blue, but their frequencies are slightly different. Similarly, R1, R2, G, and B may be used. By using such color elements, it is possible to perform a display closer to the real thing. Alternatively, power consumption can be reduced by using such color elements. Also,
As another example, when controlling the brightness using a plurality of areas for one color element,
One pixel in that area may be set as one pixel. Therefore, as an example, in the case of performing area gradation or having sub-pixels (sub-pixels), there are a plurality of regions for controlling brightness for one color element, and gradations are expressed as a whole. However, one pixel of the area for controlling the brightness may be one pixel. Therefore, in that case, one color element is composed of a plurality of pixels. Alternatively, even if there are a plurality of regions for controlling the brightness in one color element, they may be grouped together and one color element may be one pixel. Therefore, in that case, one color element is composed of one pixel. When controlling the brightness of one color element using a plurality of regions, the size of the region contributing to display may differ depending on the pixel. In addition, in a plurality of areas for controlling brightness, one color element, signals supplied to the areas may be slightly different from each other to widen the viewing angle. That is, 1
Regarding one color element, the potentials of the pixel electrodes included in a plurality of regions may be different from each other. As a result, the voltage applied to the liquid crystal molecules differs depending on each pixel electrode. Therefore, the viewing angle can be widened.

Note that the case of explicitly describing one pixel (for three colors) is a case where three pixels of R, G, and B are considered as one pixel. When explicitly describing one pixel (for one color), it is assumed that when there are a plurality of regions for one color element, they are collectively considered as one pixel.

Note that in this document (specification, claims, drawings, or the like), pixels may be arranged (arranged) in a matrix. Here, the pixels being arranged (arranged) in a matrix includes the case where the pixels are arranged in a straight line in the vertical or horizontal direction and the case where they are arranged in a jagged line. Therefore, for example, three color elements (for example, R
In the case of performing full-color display in GB), it includes a case where stripes are arranged and a case where dots of three color elements are arranged in delta. In addition, it also includes the case where Bayer is arranged. Note that the color elements are not limited to three colors, and may be more than that. For example, RGBW (W is white), RGB with one or more colors such as yellow, cyan, and magenta added thereto can be used.
Further, the size of the display area may be different for each dot of the color element. As a result, it is possible to reduce the power consumption or extend the life of the display element.

Note that an active matrix method in which an active element is included in a pixel or a passive matrix method in which an active element is not included in a pixel can be used.

In the active matrix system, not only transistors but also various active elements (active elements, non-linear elements) can be used as active elements (active elements, non-linear elements). For example, MIM (Metal Insulator Metal) and TFD (
It is also possible to use Thin Film Diode) or the like. Since these elements have few manufacturing steps, the manufacturing cost can be reduced or the yield can be improved. Furthermore, since the size of the element is small, the aperture ratio can be improved, and low power consumption and high brightness can be achieved.

In addition to the active matrix type, it is also possible to use a passive matrix type that does not use active elements (active elements, non-linear elements). Since no active element (active element or non-linear element) is used, the number of manufacturing steps is small, and the manufacturing cost can be reduced or the yield can be improved. Further, since no active element (active element or non-linear element) is used, the aperture ratio can be improved, and low power consumption and high brightness can be achieved.

Note that a transistor is an element having at least three terminals including a gate, a drain, and a source, has a channel region between the drain region and the source region, and has a drain region, the channel region, and the source region. Current can be passed through and. Here, since the source and the drain are changed depending on the structure of the transistor, operating conditions, and the like, it is difficult to determine which is the source or the drain. Therefore, in this document (specification, claims, drawings, or the like), a region functioning as a source and a drain may not be called a source or a drain. In that case, as an example, they may be referred to as a first terminal and a second terminal, respectively. Alternatively, each may be referred to as a first electrode and a second electrode. Alternatively, it may be referred to as a source region and a drain region.

The transistor may be an element having at least three terminals including a base, an emitter, and a collector. In this case as well, the emitter and collector are similarly connected to the first terminal and the second terminal.
Sometimes referred to as a terminal.

Note that a gate means the whole including a gate electrode and a gate wiring (also referred to as a gate line, a gate signal line, a scan line, a scan signal line, or the like), or part thereof. The gate electrode refers to a part of a conductive film which overlaps with a semiconductor which forms a channel region with a gate insulating film interposed therebetween. In addition, a part of the gate electrode is an LDD (Lightly Dop).
In some cases, the ed drain region or the source region (or the drain region) overlaps with the gate insulating film. A gate wiring is a wiring for connecting between gate electrodes of transistors, a wiring for connecting between gate electrodes of pixels, or a wiring for connecting a gate electrode and another wiring. Say

However, there is a portion (region, conductive film, wiring, or the like) which also functions as a gate electrode and also functions as a gate wiring. Such a portion (a region, a conductive film, a wiring, or the like) may be called either a gate electrode or a gate wiring. That is, there is a region where the gate electrode and the gate wiring cannot be clearly distinguished. For example, in the case where a part of extended gate wiring and a channel region overlap with each other, that portion (region, conductive film, wiring, or the like) functions as a gate wiring, but also as a gate electrode. It's working. Therefore, such a portion (region, conductive film, wiring, or the like) may be called either a gate electrode or a gate wiring.

Note that a portion (region, conductive film, wiring, or the like) formed of the same material as the gate electrode and forming and connecting with the same island as the gate electrode may be referred to as a gate electrode. Similarly, a portion (a region, a conductive film, a wiring, or the like) which is formed using the same material as the gate wiring and forms and is connected to the same island as the gate wiring may be referred to as a gate wiring. In a strict sense, such a portion (a region, a conductive film, a wiring, or the like) may not overlap with the channel region or may not have a function of connecting to another gate electrode. However, due to the specifications at the time of manufacturing, etc., it is formed of the same material as the gate electrode or the gate wiring, and forms the same island as the gate electrode or the gate wiring and is connected (region, conductive film, wiring, etc.) There is. Therefore, such a portion (region, conductive film, wiring, or the like) may also be called a gate electrode or a gate wiring.

Note that, for example, in a multi-gate transistor, one gate electrode is often connected to another gate electrode by a conductive film formed using the same material as the gate electrode. Such a portion (region, conductive film, wiring, or the like) is a portion (region, conductive film, wiring, or the like) for connecting the gate electrode and the gate electrode, and thus may be called a gate wiring. Since the above transistor can be regarded as one transistor, it may be called a gate electrode. That is, a portion (a region, a conductive film, a wiring, or the like) formed of the same material as the gate electrode or the gate wiring and connected to form the same island as the gate electrode or the gate wiring is connected to the gate electrode or the gate wiring. You can call me. Further, for example, a conductive film in a portion connecting the gate electrode and the gate wiring, which is formed of a material different from that of the gate electrode or the gate wiring, may be referred to as a gate electrode. You can call it.

Note that a gate terminal means a part of a portion of a gate electrode (a region, a conductive film, a wiring, or the like) or a portion electrically connected to the gate electrode (a region, a conductive film, a wiring, or the like). ..

Note that when a gate wiring, a gate line, a gate signal line, a scan line, a scan signal line, or the like is referred to, a gate of a transistor might not be connected to the wiring. In this case, the gate wiring, the gate line, the gate signal line, the scanning line, and the scanning signal line are formed in the same layer as the gate of the transistor, the wiring formed of the same material as the gate of the transistor, or the gate of the transistor at the same time. It may mean a formed wiring. Examples include a storage capacitor wiring, a power supply line, and a reference potential supply wiring.

Note that the source refers to the whole including a source region, a source electrode, and a source wiring (also referred to as a source line, a source signal line, a data line, a data signal line, or the like), or part thereof. The source region refers to a semiconductor region containing a large amount of P-type impurities (boron, gallium, or the like) and N-type impurities (phosphorus, arsenic, or the like). Therefore, a region containing a small amount of P-type impurities or N-type impurities, that is, a so-called LDD (Lightly Doped Drain) region is not included in the source region. The source electrode is a part of the conductive layer which is formed of a material different from that of the source region and is electrically connected to the source region. However, the source electrode may also be referred to as a source electrode including the source region. A source wiring is a wiring for connecting source electrodes of transistors, a wiring for connecting source electrodes of pixels, or a wiring for connecting a source electrode and another wiring. Say

However, there is a portion (a region, a conductive film, a wiring, or the like) which also functions as a source electrode and a source wiring. Such a portion (a region, a conductive film, a wiring, or the like) may be referred to as a source electrode or a source wiring. That is, there is a region where the source electrode and the source wiring cannot be clearly distinguished. For example, when part of the source wiring which is extended and arranged overlaps with the source region, that portion (region, conductive film, wiring, or the like) functions as a source wiring, but as a source electrode. Will also be working. Therefore, such a portion (a region, a conductive film, a wiring, or the like) may be referred to as a source electrode or a source wiring.

Note that a portion formed of the same material as the source electrode and connected by forming the same island as the source electrode (region, conductive film, wiring, or the like) or a portion connecting the source electrode and the source electrode (region) , Conductive film, wiring, etc.) may also be referred to as a source electrode. Further, a portion overlapping with the source region may be called a source electrode. Similarly, a region formed of the same material as the source wiring and connected by forming the same island as the source wiring may be referred to as a source wiring. In a strict sense, such a portion (region, conductive film, wiring, or the like) may not have a function of connecting to another source electrode. However, there is a portion (region, conductive film, wiring, etc.) formed of the same material as the source electrode or the source wiring and connected to the source electrode or the source wiring due to the specifications at the time of manufacturing. Therefore, such a portion (region, conductive film, wiring, or the like) may also be referred to as a source electrode or a source wiring.

Note that, for example, a conductive film in a portion connecting a source electrode and a source wiring, which is formed using a material different from that of the source electrode or the source wiring, may be referred to as a source electrode. You can call it.

Note that a source terminal refers to a part of a source region, a source electrode, or a portion (a region, a conductive film, a wiring, or the like) electrically connected to the source electrode.

Note that when referred to as a source wiring, a source line, a source signal line, a data line, a data signal line, or the like,
The source (drain) of the transistor may not be connected to the wiring. In this case, the source wiring, the source line, the source signal line, the data line, and the data signal line are formed using the same layer as the source (drain) of the transistor and the same material as the source (drain) of the transistor. Alternatively, it may mean a wiring formed at the same time as the source (drain) of the transistor. Examples include a storage capacitor wiring, a power supply line, and a reference potential supply wiring.

The drain is the same as the source.

Note that a semiconductor device refers to a device including a circuit including a semiconductor element (a transistor, a diode, a thyristor, or the like). Furthermore, all devices that can function by utilizing semiconductor characteristics may be called semiconductor devices. Alternatively, a device including a semiconductor material is referred to as a semiconductor device.

Note that the display element means an optical modulation element, a liquid crystal element, a light emitting element, an EL element (organic EL element, inorganic EL element or EL element containing an organic substance and an inorganic substance), an electron emission element, an electrophoretic element, a discharge element, a light reflection element. An element, a light diffraction element, a digital micromirror device (DMD), and the like. However, it is not limited to this.

Note that a display device refers to a device having a display element. Note that the display device may include a plurality of pixels each including a display element. Note that the display device may include a peripheral driver circuit that drives a plurality of pixels. The peripheral driver circuit for driving the plurality of pixels may be formed on the same substrate as the plurality of pixels. Note that the display device includes a peripheral drive circuit arranged on the substrate by wire bonding, bumps, or the like, an IC chip connected by a so-called chip-on-glass (COG), or an IC chip connected by a TAB or the like. You may stay. The display device may include a flexible printed circuit (FPC) to which an IC chip, a resistance element, a capacitance element, an inductor, a transistor, and the like are attached. The display device may include a printed wiring board (PWB) that is connected through a flexible printed circuit (FPC) or the like and has an IC chip, a resistance element, a capacitance element, an inductor, a transistor, or the like attached thereto. The display device may include an optical sheet such as a polarizing plate or a retardation plate. Note that the display device may include a lighting device, a housing, a voice input/output device, an optical sensor, and the like. Here, the illumination device such as the backlight unit may include a light guide plate, a prism sheet, a diffusion sheet, a reflection sheet, a light source (LED, cold cathode tube, etc.), a cooling device (water cooling type, air cooling type), and the like. good.

The illuminating device refers to a device including a backlight unit, a light guide plate, a prism sheet, a diffusion sheet, a reflection sheet, a light source (LED, cold cathode tube, hot cathode tube, etc.), a cooling device, and the like.

Note that a light emitting device refers to a device including a light emitting element or the like. When a light emitting element is included as a display element, the light emitting device is one of specific examples of the display device.

The reflection device refers to a device having a light reflection element, a light diffraction element, a light reflection electrode, and the like.

The liquid crystal display device means a display device having a liquid crystal element. Liquid crystal display devices include direct-view type, projection type, transmissive type, reflective type, and semi-transmissive type.

Note that a driving device refers to a device including a semiconductor element, an electric circuit, and an electronic circuit. For example, a transistor that controls input of a signal from a source signal line into a pixel (sometimes referred to as a selection transistor or a switching transistor), a transistor that supplies a voltage or current to a pixel electrode, a voltage or current to a light-emitting element A transistor or the like for supplying the is an example of a driving device. Further, a circuit that supplies a signal to a gate signal line (sometimes referred to as a gate driver or a gate line driver circuit) and a circuit that supplies a signal to a source signal line (sometimes referred to as a source driver or a source line driver circuit) ) And the like are examples of the driving device.

Note that the display device, the semiconductor device, the lighting device, the cooling device, the light emitting device, the reflecting device, the driving device, and the like may be overlapped with each other. For example, the display device may include a semiconductor device and a light emitting device. Alternatively, the semiconductor device may include a display device and a driver.

In addition, when explicitly describing that B is formed on A or B is formed on A, it is limited to that B is directly formed on A. Not done. The case where it is not in direct contact, that is, the case where another object is interposed between A and B is also included. Here, A and B are objects (for example, devices, elements, circuits, wirings, electrodes, terminals, conductive films, layers,
Etc.).

Thus, for example, if it is explicitly stated that layer B is formed on layer A (or on layer A), layer B is formed directly on layer A. It includes a case and a case where another layer (for example, the layer C or the layer D) is formed directly on the layer A and the layer B is formed directly on the other layer. The other layers (for example, the layer C and the layer D) may be a single layer or multiple layers.

Further, the same applies to the case where it is explicitly described that B is formed above A, and the present invention is not limited to the case where B is directly in contact with A, The case where another object intervenes is also included. Therefore, for example, when the layer B is formed above the layer A, the case where the layer B is formed directly on the layer A and the case where another layer is formed directly on the layer A (For example, the layer C, the layer D, etc.) are formed, and the case where the layer B is formed in direct contact therewith are also included. The other layers (for example, the layer C and the layer D) may be a single layer or multiple layers.

In addition, when it is explicitly described that B is formed directly on A, it includes a case where B is formed on A directly. It does not include cases where objects are present.

The same applies to the case where B is below A or B is below A.

In addition, it is desirable that a singular number be explicitly described as a singular number.
However, the present invention is not limited to this, and a plurality may be possible. Similarly, when explicitly described as plural, plural is desirable. However, the present invention is not limited to this, and it is possible that the number is singular.

According to the present invention, a wide viewing angle display can be realized. Further, a display device with excellent contrast can be obtained. In addition, a display device with excellent display quality can be provided.
In addition, it is possible to provide a display device that is not easily affected by noise and can perform a clear display. Alternatively, a display device in which display deterioration does not easily occur can be provided. Alternatively, a display device having an excellent product life can be provided.

The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. FIG. 6 illustrates an example of a display device including a pixel of the present invention. 6A and 6B each illustrate a structural example of a pixel included in a display device of the present invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. 4A and 4B are diagrams illustrating one operation method of the display device illustrated in FIG. 3. 6A and 6B are diagrams illustrating operation of the pixel illustrated in FIG. 5. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. FIG. 10 is a diagram showing an example of a pixel layout of a display device according to the present invention. FIG. 6 is a diagram illustrating a liquid crystal mode of a display device according to the present invention. FIG. 6 is a diagram illustrating a liquid crystal mode of a display device according to the present invention. FIG. 6 is a diagram illustrating a liquid crystal mode of a display device according to the present invention. FIG. 6 is a diagram illustrating a liquid crystal mode of a display device according to the present invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows an example of the peripheral structural member of the display apparatus which concerns on this invention. The figure which shows an example of the peripheral structural member of the display apparatus which concerns on this invention. The figure which shows an example of the peripheral structural member of the display apparatus which concerns on this invention. The figure which shows an example of the peripheral structural member of the display apparatus which concerns on this invention. The figure which shows an example of the panel circuit structure of the display apparatus which concerns on this invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. 6A and 6B each illustrate an example of a structure of a transistor included in a display device of the present invention. 6A and 6B each illustrate an example of a structure of a transistor included in a display device of the present invention. 6A and 6B each illustrate an example of a structure of a transistor included in a display device of the present invention. 6A and 6B each illustrate an example of a structure of a transistor included in a display device of the present invention. 6A and 6B each illustrate an example of a structure of a transistor included in a display device of the present invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. The figure which shows one structural example of the display apparatus which concerns on this invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. 11A to 11C are diagrams showing electronic devices using a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. FIG. 6 is a diagram showing an example of a driving method of a display device according to the present invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure which shows an example of the pixel structure of this invention. The figure explaining a prior art.

Hereinafter, one embodiment of the present invention will be described. However, those skilled in the art can easily understand that the present invention can be carried out in many different modes, and that the form and details can be variously changed without departing from the spirit and the scope of the present invention. To be done. Therefore, it should not be construed as being limited to the description of this embodiment. In the structure of the present invention described below, the same reference numerals are used in common in different drawings, and the description thereof will be omitted.

(Embodiment 1)
The basic configuration of the pixel of the present invention will be described with reference to FIG. The pixel shown in FIG. 1 includes a first switch 111, a second switch 112, a third switch 113, a first resistor 114, a second resistor 115, a first liquid crystal element 121, and a second liquid crystal element 122. , The first storage capacitor 131
And a second storage capacitor 132. In addition, the pixel includes a signal line 116 and a first scan line 117.
, And the second scanning line 120 and the Cs line 119. Note that the first liquid crystal element 121
Each of the second liquid crystal element 122 and the second liquid crystal element 122 includes at least a pixel electrode, a common electrode 118, and a liquid crystal controlled by the pixel electrode and the common electrode 118.

In FIG. 1, the pixel electrode of the first liquid crystal element 121 is connected to the signal line 116 via the first switch 111. In addition, the pixel electrode of the first liquid crystal element 121 is the second switch 1
The pixel electrode of the second liquid crystal element 122 is also connected via 12 and the first resistor 114. When the connection point between the first resistor 114 and the pixel electrode of the second liquid crystal element 122 is a node 142, the node 142 passes through the third switch 113 and the second resistor 115 and the Cs line 119.
Is connected with. A node 141 is a connection point between the second switch 112 and a wiring which connects the pixel electrode of the first liquid crystal element 121 and the first switch 111.

The first switch 111 and the second switch 112 are turned on and off by the first scanning line 11
On/off of the third switch 113 is controlled by a signal input to the first scan line 117 and a signal input to the second scan line 120. Here, a case where each switch is controlled using a scanning line will be described, but the switch control method is not limited to this.

An image signal corresponding to a video signal, that is, a potential corresponding to a gray scale of a pixel is input to the signal line 116.

Note that the liquid crystal element exhibits voltage holding characteristics, but its holding ratio is not 100%. Therefore, in order to maintain the held voltage, the first liquid crystal element 121 and the second liquid crystal element 1 in the pixel shown in FIG.
A first storage capacitor 131 and a second storage capacitor 132 are provided corresponding to each of 22. Specifically, the pixel electrode of the first liquid crystal element 121 is Cs via the first storage capacitor 131.
The pixel electrode of the second liquid crystal element 122 is connected to the line 119, and is connected to the Cs line 119 via the second storage capacitor 132. Note that the voltage holding characteristic of the liquid crystal element depends on the liquid crystal material, impurities mixed therein, the size of the pixel, and the like. Therefore, when the voltage holding rate of the liquid crystal element is high, a holding capacitor is particularly provided as shown in FIG. You don't have to. In addition, for example, the first liquid crystal element 1
When the second liquid crystal element 122 contributes less to the display than the second liquid crystal element 21, the second storage capacitor 132 provided for the second liquid crystal element 122 having less display contribution may be omitted.

In FIG. 1, the node 141 is connected to the node 142 via the second switch 112 and the first resistor 114 in this order, but the first resistor 114 and the second switch 112 are connected in that order. Is also good. In addition, the node 142 has a second resistor 115 and a third switch 1
It may be connected to the Cs line 119 via 13 in order. Of course, as shown in FIG. 78, in the second switch 112 and the first resistor 114, and in the third switch 113 and the second resistor 115, the connection relationship between the switch and the resistor may be reversed.

Further, each of the first liquid crystal element 121 and the second liquid crystal element 122 may be composed of a plurality of liquid crystal elements. Similarly, each of the first storage capacitor 131 and the second storage capacitor 132 may be composed of a plurality of storage capacitors. For example, the first liquid crystal element 121,
FIG. 79 shows a case where each of the second liquid crystal elements 122 is composed of two liquid crystal elements, and each of the first storage capacitor 131 and the second storage capacitor 132 is composed of two storage capacitors.

The operation of the pixel of FIG. 1 will be described. As described above, the first switch 111 and the second switch 111
ON/OFF of the switch 112 is controlled by inputting a signal to the first scan line 117, and here, by inputting a high level (hereinafter referred to as H level) to the first scan line 117, the first switch A case where the 111 and the second switch 112 are turned on will be described. In addition, the third switch 113, which is controlled by both signals input to the first scan line 117 and the second scan line 120, outputs H to both the first scan line 117 and the second scan line 120. The case where it turns on only when the level is input will be described. Therefore, in this case, when a Low level (hereinafter, referred to as L level) is input to the first scan line 117, these switches are turned off, and the third switch 113 is further connected to the first scan line 117. Even when the H level and the L level are input to the second scanning line 120, they are turned off.

By using the first switch 111, the second switch 112, and the third switch 113 as described above, a period for inputting a potential according to the gradation of the pixel to the pixel, that is, a writing period is divided into a first half and a second half. To do. In the first half, the first switch 111 and the second switch 112 except the third switch 113 are turned on, and in the second half, the third switch 113 is turned on in addition to the first switch 111 and the second switch 112. And Thus, by electrically disconnecting the signal line 116 and the Cs line 119 in the first half portion and electrically connecting them in the second half portion, it becomes possible to quickly write the video signal to the pixel.

First, in the first half of the writing period, the H level is applied to the first scanning line 117 and the second scanning line 1
The L level is input to 20, and the first switch 111 and the second switch 112 are turned on. The potential corresponding to the grayscale of the pixel, which is input from the signal line 116, is supplied to the pixel electrode of the first liquid crystal element 121 and the first electrode of the first storage capacitor 131 through the first switch 111. .. Further, this potential is supplied to the pixel electrode of the second liquid crystal element 122 and the first electrode of the second storage capacitor 132 via the second switch 112 and the first resistor 114. At this time, the third
By turning off the switch 113 of the first liquid crystal element 121 and the second liquid crystal element 1
It is possible to quickly supply a potential to each of the pixel electrodes 22.

After that, in the latter half of the writing period, the H level is also input to the second scan line 120 to turn on the third switch 113 in addition to the first switch 111 and the second switch 112. In this way, the signal line 116 and the Cs line 119 are electrically connected. Thus, the potentials supplied to the pixel electrodes of the first liquid crystal element 121 and the second liquid crystal element 122 in the first half of the writing period can be adjusted to the optimum potential according to the gray scale of the pixel. ..

Note that the potential supplied to the pixel electrode of the second liquid crystal element 122 and the first electrode of the second storage capacitor 132 is the same as the potential at the node 142, and the potential is the potential difference between the node 141 and the Cs line 119. And the resistance values of the first resistor 114 and the second resistor 115. That is, the pixel electrode of the second liquid crystal element 122 is supplied with a potential which is input from the signal line 116 and is divided by the first resistor 114 and the second resistor 115 according to the grayscale of the pixel. Has been done. Note that the potential according to the gray scale of the pixel input from the signal line 116 is Vsig, the resistance value of the first resistor 114 is R1, and the resistance value of the second resistor 115 is R.
2. If the potential supplied to the Cs line 119 is Vcs, the potential of the node 141 becomes Vsig. Therefore, the potential of the node 142 in the latter half of the writing period is Vcs+(Vsi).
g-Vcs)×R2/(R1+R2).

Note that the first storage capacitor 131 has a potential corresponding to the grayscale input from the signal line 116 and Cs.
The potential difference between the potential of the line 119 and the potential divided by the resistance of the second storage capacitor 132 and the Cs line 1
The potential difference from the potential of 19 is held.

Next, the L level is input to the first scan line 117. Then, the first switch 111, the second switch 112, and the third switch 113 are turned off, and the signal line 116, the first liquid crystal element 121, and the second liquid crystal element 122 are electrically cut off from each other. However, the first storage capacitor 131 holds the potential difference between the potential corresponding to the grayscale input from the signal line 116 and the potential of the Cs line 119, and the second storage capacitor 132 stores the resistance-divided potential. The potential difference from the potential of the Cs line 119 is held. Therefore, the pixel electrode of the first liquid crystal element 121 is the signal line 1
The potential corresponding to the gradation of the pixel input from 16 can be maintained, and the second liquid crystal element 12
The resistance-divided potential can be maintained even in the second pixel electrode. The L level may be supplied not only to the first scanning line 117 but also to the second scanning line 120 together with the first scanning line 117. In any case, the first switch 111, the second switch 112, and the third switch 113 may be turned off.

In this way, the gray scale of the pixel is expressed using the potential difference, that is, the voltage held in the first liquid crystal element 121 and the second liquid crystal element 122. First liquid crystal element 121 and second liquid crystal element 12
Since different voltages are applied in Nos. 2 and 3, the liquid crystals included in each liquid crystal element show different alignments. Therefore, the viewing angle characteristics can be improved.

Note that the gray scale represented by a pixel is determined by the alignment of liquid crystals included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel; The corresponding potential needs to be determined in consideration of these.

In the first half of the writing period, the signal line 116 and the Cs line 119 are electrically disconnected,
In the latter half part, by electrically connecting these, each of the pixel electrodes of the first liquid crystal element 121 and the second liquid crystal element 122 can be accelerated by a potential according to the gradation of the pixel.
Therefore, it becomes possible to quickly write the video signal to the pixel.

Further, as shown in FIG. 2, the first switch 111, the second switch 112, and the third switch 113 may be controlled using different scanning lines. In FIG. 2, the first switch 11
In the case where the control unit 1 controls the third scanning line 201, the second switch 112 controls the first scanning line 117, and the third switch 113 controls the first scanning line 117 and the second scanning line 120. It has been described. Note that the pixel shown in FIG. 2 can be operated similarly to the pixel shown in FIG.

By the way, in the case of the pixel configuration as described above, the voltage applied to the second liquid crystal element 122 is smaller than that applied to the first liquid crystal element 121. Therefore, if the second resistor 115 is made smaller than the first resistor 114 too much, the voltage applied to the second liquid crystal element 122 becomes smaller than the threshold voltage of the liquid crystal, and the liquid crystal included in the second liquid crystal element 122 is It may not drive. Therefore, the resistance value R2 of the second resistor 115 is larger than the resistance value R1 of the first resistor 114 (R2>
R1) is preferred. Of course, the relationship of the resistance values is not limited to this, and it is sufficient that the liquid crystals of the first liquid crystal element 121 and the second liquid crystal element 122 are driven and the gray scale can be expressed by using both the liquid crystals. The threshold voltage of the liquid crystal refers to the critical value of the voltage required to drive the liquid crystal.

Further, in FIG. 1, the resistance values of the first resistor 114 and the second resistor 115 are large, and the first switch 111 is provided in each of the node 141 and the node 142 without the second switch 112 and the third switch 113. These switches may not be provided as long as the potential at the time of being input from the signal line 116 can be maintained even after the switch is turned off. For example, the first resistor 11
If the resistance value of 4 is large, the second switch 1 provided between the node 141 and the node 142
12 may be omitted, or if the resistance value of the second resistor 115 is large, the third switch 113 provided between the node 142 and the Cs line 119 may be omitted. Of course, when both are large, the second switch 112 and the third switch 113 can be omitted.

Next, a display device including the above-described pixel shown in FIG. 1 will be described with reference to FIG.

The display device includes a signal line driver circuit 311, a scan line driver circuit 312, and a pixel portion 313,
In the pixel portion 313, a plurality of signal lines S1 to Sm arranged in a column direction from the signal line driver circuit 311 and a first scan line G1_ arranged in a row direction from the scan line driver circuit 312 are arranged.
1 to G1_n, second scan lines G2_1 to G2_n and Cs lines Cs_1 to Cs_n, and a plurality of pixels 314 arranged in a matrix corresponding to the signal lines S1 to Sm. Each pixel 314 includes a signal line Sj (one of the signal lines S1 to Sm), a first scanning line G1_i (one of the scanning lines G1 to Gn), and a second scanning line G2_i. , Cs line C
It is connected to s_i.

The signal line Sj, the first scanning line G1_i, the second scanning line G2_i, and the Cs line Cs_i are the signal line 116, the first scanning line 117, the second scanning line 120, and the Cs line 11 of FIG. 1, respectively.
Equivalent to 9. The common electrode 118 in FIG. 1 is commonly or electrically connected between the plurality of pixels 314 and is supplied with the same potential. The Cs line 119 and the common electrode 118
In the case of setting the same potential to and, the conductive fine particles and wirings may be electrically connected to the outside of the pixel portion 313.

Rows of pixels to be operated are sequentially selected by a signal input from the scan line driver circuit 312 to the first scan line G1_i, and the signal line driver circuit 311 supplies the signal lines S1 to Sm to each of the pixels belonging to the selected row. A potential corresponding to the gradation of each pixel is supplied via the.

As shown in FIG. 17, for example, when the i-th row is selected and the writing period ends, a signal is written to the pixels belonging to the i+1-th row. Note that FIG. 17 excerpts and describes the operation of the first switch 111 shown in FIG. 1 that can faithfully represent the write period in each row. Then, the pixel which has completed the writing period in the i-th row expresses gray scale by the voltage held in the first liquid crystal element and the second liquid crystal element in the period.

Note that an H-level signal is input only to the first scan line G1_i in the first half of the writing period, and an H-level signal is also input to the second scan line G2_i in the second half. Therefore, the pixel can express gradation as described above by the potential supplied from the signal line Sj during the writing period.

Note that the polarity of the voltage applied to the pixel electrode is reversed with respect to the potential of the common electrode (common potential) in the liquid crystal element at regular intervals in order to suppress display unevenness such as deterioration of the liquid crystal material and flicker. It is preferable to use the inversion drive in which the drive is performed. In this specification, when the potential of the pixel electrode is higher than that of the common electrode, a positive voltage is applied to the liquid crystal element, and when the potential of the common electrode is higher than that of the pixel electrode, a negative voltage is applied to the liquid crystal element. write. In addition, a video signal input from the signal line when a positive voltage is applied to the liquid crystal element is a positive signal, and a video signal input from the signal line when a negative voltage is applied is a negative signal. Notated as a sex signal. Examples of the inversion driving include frame inversion driving, source line inversion driving, gate line inversion driving, dot inversion driving, and the like.

The frame inversion drive is a drive method in which the polarity of the voltage applied to the liquid crystal element is inverted every frame period. Note that one frame period corresponds to a period for displaying an image for one pixel, and the period is not particularly limited, but at least 1/60 second so that a person who sees the image does not feel flicker. The following is preferable.

Further, it is desirable to shorten the cycle and increase the frequency to reduce the blur of the image in the moving image. Desirably, the cycle is 1/120 second or less (frequency is 120 Hz or more). More preferably, the cycle is 1/180 seconds or less (frequency is 180 Hz or more). When improving the frame frequency in this way, it is necessary to interpolate the image data when the frame frequency does not match the frame frequency of the original image data. In this case, it is possible to display at a high frame frequency by interpolating the image data using the motion vector. As described above, the motion of the image is displayed smoothly, and the display with less afterimage can be performed.

Further, the source line inversion driving is to invert the polarity of the voltage applied to the liquid crystal elements belonging to the pixels connected to the same signal line with respect to the liquid crystal elements belonging to the pixels connected to the adjacent signal line, and This is a driving method in which frame inversion is performed for each pixel. On the other hand, gate line inversion drive refers to the polarity of the voltage applied to the liquid crystal elements belonging to the pixels connected to the same scanning line,
This is a driving method in which the liquid crystal elements belonging to the pixels connected to the adjacent scanning lines are inverted and the frame is inverted for each pixel. The dot inversion drive is a drive method that inverts the polarity of the voltage applied to the liquid crystal element between adjacent pixels, and is a drive method that combines source line inversion drive and gate line inversion drive.

By the way, the above frame inversion drive, source line inversion drive, gate line inversion drive,
When the dot inversion drive or the like is adopted, the width of the potential required for the video signal written in the signal line is twice as large as that in the case where the inversion drive is not performed. Therefore, in order to eliminate this, in the case of frame inversion driving or gate line inversion driving, common inversion driving for inverting the potential of the common electrode may be adopted.

The common inversion drive is a drive method in which the potential of the common electrode is changed in synchronization with the inversion of the polarity applied to the liquid crystal element, and the potential required for the video signal written in the signal line is changed by performing the common inversion drive. The width can be reduced. In this case, the common electrode 118 and Cs
It is preferable that the line 119 (in FIG. 3, Cs lines Cs_1 to Cs_n) is electrically connected. The same signal is input to the common electrode 118 and the Cs line 119, which enables more appropriate display.

For example, when source line inversion driving is performed, positive and negative video signals, that is, positive and negative video signals centered on the potential of the common electrode are alternately supplied through the signal line every frame period. In such a case, the video signal is a signal that is positive or negative with respect to the potential supplied to the Cs line.

Next, FIG. 4 shows a configuration example of a pixel capable of realizing dot inversion drive. In FIG. 4, four pixels are extracted and described, and each pixel has the configuration shown in FIG. In the figure, the signal lines 116_1 and 116_2 are the same as the signal lines 116 in FIG.
7_1 and 117_2 correspond to the first scanning line 117, the second scanning lines 120_1 and 120_2 correspond to the second scanning line 120, and the Cs lines 119_1, 119_2, 419_1 and 419_2 correspond to the Cs line 119. Signals of different polarities are input to the signal lines 116_1 and 116_2. In accordance with the polarity, even a pixel belonging to the same row is different from an adjacent pixel in a Cs line, that is, Cs line.
By using the lines 119_1, 419_2 or 119_1, 419_2, a potential different from that of an adjacent pixel is supplied as shown in FIG. Dot inversion drive may be performed by driving as shown in FIG.

Note that the signal for displaying black in normally black and the signal for displaying white in normally white are |Vsig(0)|, and the potential of the common electrode is Vcom.
Then, when a positive signal is supplied to the pixel from the signal line, Vcom or more and Vsig(
It suffices that a potential of 0)+Vcom or less is supplied to the Cs line. On the other hand, in the case where a negative polarity signal is supplied to the pixel, a potential of −Vsig(0)+Vcom or more and Vcom or less may be supplied to the Cs line.

Note that when a positive polarity signal is supplied to the pixel, Vcom+α or more Vsig(0)+V
A potential equal to or lower than com is −Vsig(0)+Vc when a negative signal is supplied to the pixel.
It is preferable that a potential of om or more and Vcom-α or less is supplied to the Cs line. Where α is V
sig/2. Furthermore, more preferably, when a positive polarity signal is supplied to the pixel, V
The potential of sig(0)+Vcom is −Vsig when a negative signal is supplied to the pixel.
It is preferable that the potential of (0)+Vcom be supplied.

Thus, when the positive polarity signal is supplied to the pixel, the potential of the Cs line is set to Vsig(0
)+Vcom and, in the case where a negative signal is supplied, −Vsig(0)+Vcom, whereby the voltage applied to the second liquid crystal element 122 can be increased, and the second liquid crystal The control of the element 122 can be facilitated.

Note that when a positive polarity signal is supplied to a pixel, the potential of the Cs line is set to Vsig(0)+Vco
When the potential is higher than m, a voltage higher than Vsig(0) is always applied to the liquid crystal,
Black cannot be displayed in normally black, and white cannot be displayed in normally white. Also, when a negative signal is supplied to the pixel, -Vsig(0)+
When a potential lower than Vcom is supplied to the Cs line, black cannot be displayed in normally black and white cannot be displayed in normally white, as in the case of a positive polarity signal.

Note that in FIG. 80, Cs when the potential of Vcom is 0 V and a positive polarity signal is supplied to the pixel
The potential of the line is Vsig (0), and the potential of the Cs line when a negative signal is supplied to the pixel is -V
The case of sig(0) is described.

The method of inversion driving is not limited to the above.

In addition, the number of wirings can be reduced by sharing the wirings connected to each pixel among the pixels. In this case, various wirings can be shared between pixels as long as they operate normally. For example, the wiring can be shared with the pixel in the next row, and an example thereof will be described.

The pixel 500 shown in FIG. 5 has a first switch 111 and a second switch 112 as in FIG.
, The third switch 113, the first resistor 114, the second resistor 115, and the first liquid crystal element 121.
, A second liquid crystal element 122, a first storage capacitor 131, and a second storage capacitor 132. Note that the pixel 500 is connected to the signal line 116, the first scan line 517, the Cs line 119, and the first scan line 517 of the next row.

In the pixel shown in FIG. 1, the second scanning line 117 is used as one scanning line for controlling the third switch 113, whereas in FIG. 5, the first scanning line 517 in the next row is used. .. By thus sharing the wiring with the next row, the number of wirings can be reduced and the aperture ratio can be improved.

However, in the pixel shown in FIG. 5, when the third switch 113 is turned on, the first switch 111 and the second switch 112 in the pixel in the next row are turned on before writing is completed. That is, as shown in FIG. 18, the pixel in the next row is selected in the latter half of the writing period in the pixel 500. Note that FIG. 18 shows the writing period in the i−1th row, the ith row, and the i+1th row, and the operation of the first switch 111 that can faithfully express this, like FIG. 17, is extracted and described.

As described above, since the pixel of the next row is selected in the latter half of the writing period, the voltage applied to the first liquid crystal element 121 and the second liquid crystal element 122 included in the pixel of the next row is The voltage changes according to the gradation. However, since the video signal is written next to the pixel 500 in the pixel in the next row, setting a period during which the third switch 113 is turned on, that is, the latter half of the writing period to such an extent that display is not affected is a problem. It never happens.
Of course, this does not occur when the pixel configuration of FIG. 2, that is, when the scanning line for controlling the first switch 111 is provided separately from the first scanning line 517.

Note that in the above description, various modes can be used for the first switch 111, the second switch 112, and the third switch 113, and an electrical switch, a mechanical switch, or the like can be used. You can That is, it is not limited to a specific one as long as it can control the flow of current. For example, it may be a transistor or a diode, or a logic circuit combining these.

As shown in FIG. 6, a second transistor 612 and a third transistor 613 are used for each of the second switch 112 and the third switch 113 in FIG. 1, and the on-resistance of these transistors is used. It is also possible to realize the first resistor 114 and the second resistor 115 in and to omit these resistors. However, since the third transistor 613 needs to be controlled by both signals input to the first scan line 117 and the second scan line 120, the gate electrode has the first scan line 117 and the second scan line 117. Of two transistors 620 and 621 respectively connected to the scanning line 120.

As described above, in FIG. 1, the resistance value R2 of the second resistor 115 is equal to the first resistor 114.
6 is larger than the resistance value R1 (R2>R1), it is preferable that the third transistor 613 has a larger on-resistance than the second transistor 612 in the configuration shown in FIG. Therefore, when the channel width of the second transistor 612 is W2, the channel length is L2, the channel width of the third transistor 613 is W3, and the channel length is L3,
It is preferable to use a transistor such that 2/L2>W3/L3. Here, the channel length L of the third transistor 613 is the transistor 620 connected in series,
When the channel widths W of 621 are equal, the value corresponds to the sum of the channel lengths of the transistors. However, the relationship is not limited to this. Of course, the pixel configuration is not limited to this, and for example, as shown in FIG. 81, the second transistor 612 and the third transistor 612 are provided in the second switch 112 and the third switch 113 in FIG. 1, respectively. The resistor does not have to be omitted by using the transistor 613.

Further, when a transistor (here, referred to as a first transistor) is used for the first switch 111 in FIG. 1, it is preferable that the on-resistance of the first transistor be lower, and the channel width of the first transistor be lower. Is preferably W1 and the channel length is L1, W1/L1 is preferably larger. FIG. 83 shows the case where the first transistor 8411 is used for the first switch 111 in the structure shown in FIG. Note that when the first transistor 8411 is compared with the second transistor 612 and the third transistor 613, W1/L
It is preferable to use a transistor in which 1>W2/L2>W3/L3. However, it is not limited to this.

The connection relationship between the transistors 620 and 621 included in the third transistor 613 is such that the node 142 is connected to the Cs line 119 through the transistor 620 and the transistor 621 in this order as illustrated in FIG. Alternatively, as shown in FIG. 7, the node 142 may be provided so as to be connected to the Cs line 119 through the transistor 621 and the transistor 620 in order. In the pixel configuration shown in FIG. 7, the third transistor 613 is used.
Since the transistor connected to the node 142 among the transistors included in the transistor is turned off, the gate capacitance of the transistor can be made smaller than that in the case where the transistor is turned on. In the above, it becomes possible to supply the potential to the respective pixel electrodes of the first liquid crystal element 121 and the second liquid crystal element 122 more quickly.

Further, in order to increase the on-resistance of the third transistor 613, as shown in FIG. 8, a multi-gate circuit in which two transistors are connected in series to a transistor 621 that constitutes the third transistor 613 in FIG. The type transistor 821 may be used. Although FIG. 8 shows the case where two transistors are connected in series, the number of transistors connected in series is not particularly limited.

Note that the channel length L of the transistor 821 acts as the sum of the channel lengths of the respective transistors when the channel widths W of the two transistors connected in series are equal to each other. Therefore, W/L is likely to be smaller and ON resistance can be increased. Therefore, the on-resistance of the transistor 821 can be easily increased by using a multi-gate transistor. Therefore, the on resistance of the third transistor 613 can be easily increased as compared with the on resistance of the second transistor 212.

In addition to the transistor 621, a multi-gate transistor 920 may be used as the transistor 620 in FIG. 6 as illustrated in FIG.

In addition, for example, when the on resistance of the third transistor 613 is extremely smaller than that of the second transistor 612, the voltage applied to the second liquid crystal element 122 is the second liquid crystal element 122.
When the voltage is less than or equal to the threshold voltage of the liquid crystal included in, the transistor 1014 which is diode-connected as a resistor as shown in FIG. 10 may be provided in series with the third transistor 613.

With the diode-connected transistor 1014, the second storage capacitor 132 can hold at least a voltage equal to or higher than the threshold voltage of the transistor 1014. Therefore, by using the diode-connected transistor 1014, the second liquid crystal element 122 is
It is possible to increase the voltage applied to the second liquid crystal element 122 and drive the liquid crystal included in the second liquid crystal element 122 more reliably. The diode has non-linearity and has a larger resistance value in a region where the voltage is low, and is particularly effective in such a case. of course,
It is also possible to use a resistor. Note that the potential input from the signal line 116 is illustrated as a positive potential here, an N-channel transistor is used as the transistor 1014, and the drain electrode of the transistor 1014 is the third transistor 613. An example of connection is shown. Needless to say, a P-channel transistor can be used as the transistor 1014. However, in this case, the source electrode is connected to the third transistor 613.

Note that when source line inversion or dot inversion driving is performed as described above, positive and negative image signals, that is, positive and negative image signals centering on the potential of the common electrode are signaled every frame period. Alternatingly supplied via wires. In such a case, the image signal is a signal that is positive and negative with respect to the potential supplied to the Cs line. Therefore, the potential of the Cs line 119 may be changed between when the positive image signal is input and when the negative image signal is input. That is, the potential of the Cs line 119 may be lower when the negative polarity signal is input than when the positive polarity signal is input. As a result, it is possible to appropriately supply a voltage to each pixel electrode. Note that the pixel shown in FIG. 10 may have a structure as shown in FIG. 11 so that it can handle both positive and negative image signals. The pixel shown in FIG. 11 has a diode-connected transistor 1014 in FIG. 10 and a diode-connected transistor 11 in parallel.
14 is further provided. Note that when these transistors are transistors of the same conductivity type, the transistors 1014 and 1114 are connected so that their drain electrodes are different from each other. With such a configuration, the potential of the Cs line 119 and the signal line 1
Even if the relationship of the potentials supplied from 16 is reversed, the second storage capacitor 132 can hold at least the threshold voltage of the transistor 1014 or the transistor 1414. Therefore, the voltage applied to the second liquid crystal element 122 can be increased, and the liquid crystal included in the second liquid crystal element 122 can be driven more reliably. Note that the pixel configuration shown in FIG. 11 may be used even when such a driving method is not performed.

In this specification, the common electrode 118 and the Cs line 119 may be supplied with different potentials or the same potential. Further, as shown in FIG. 82, the common electrode 1
18 and the Cs line 119 may be shared. Note that FIG. 82 illustrates the case where the common electrode 118 and the Cs line 119 in FIG. 1 are shared by using the wiring 8300.

Although FIGS. 1 to 11 described above show the case where two liquid crystal elements are provided in one pixel, the number of liquid crystal elements included in the pixel is not particularly limited. In FIG. 12, one pixel has three liquid crystal elements.
The following shows the case where one is included. The pixel shown in FIG. 12 includes a transistor 1214, a liquid crystal element 1223, and a storage capacitor 1233 in addition to the structure of the pixel shown in FIG. In FIG.
The pixel electrode of the liquid crystal element 1223 is connected to the signal line 116 via the second transistor 612 and the first switch 111. Further, when a connection point between the pixel electrode of the liquid crystal element 1223 and the second transistor 612 is a node 1200, the node 1200 is connected to the node 142 through the transistor 1214. Note that the gate electrode of the transistor 1214 is similar to that of the second transistor 612 and the third transistor 613 in the first scan line 1
It is connected to 17. In addition, the node 1200 receives the Cs line 119 via the storage capacitor 1233.
Is connected with. Thus, in FIG. 12, the transistor 1214 and the liquid crystal element 1223 are
And a unit 1201 having a storage capacitor 1233 are provided between the second transistor 612 and the node 142. Note that when the number of liquid crystal elements included in a pixel is increased, for example, the number of units 1201 may be increased. Of course, it is not limited to this.

Moreover, one pixel may have a plurality of the above-described pixel configurations. A configuration example of such a pixel is shown in FIG. The pixel shown in FIG. 13 has two sub-pixels 1300a and 1300b,
The gradation of one pixel is expressed using these sub-pixels. In FIG. 13, the pixel configuration shown in FIG. 6 is described for each of the sub-pixels. However, sub-pixels 1300a and 1300b
The signal line 116, the first scanning line 117, and the second scanning line 120 which are connected to each other are shared by the sub-pixels. Cs connected to the sub-pixels 1300a and 1300b
By supplying different potentials to the lines 119, different voltages can be applied to the liquid crystal elements belonging to the respective subpixels. In this way, it is possible to further improve the viewing angle by utilizing the difference in the alignment of the liquid crystal in each sub-pixel.

In addition, as shown in FIG. 13, the signal line 116, the first scanning line 117, and the second scanning line 117 are provided between the sub-pixels.
Although the case where the scanning line 120 of 1 is used as the common wiring is shown, as shown in FIG. 14, only the scanning lines of the first scanning line 117 and the second scanning line 120 are used for the sub-pixels 1400a and 1400.
You may share between b. In addition, as shown in FIG. 15, only the signal line 116 is connected to the sub-pixel 1500.
a and 1500b may be shared, and the gradation of one pixel may be expressed using these sub-pixels. Note that the wiring shared by the sub-pixels is not limited to the above, and may be the Cs line 119, or two or more wirings may be shared as shown in FIGS. 13 and 14.

The shared wiring does not have to be a wiring that performs the same function between the sub-pixels. For example,
As shown in FIG. 16, of the scanning lines which control the third switch 113 included in one of the sub-pixels 1600a, the scanning line different from the first scanning line 117 is located in the other sub-pixel 1 located in the next stage.
The first scan line 117 included in 600b can also be used.

Note that in the pixel illustrated in FIG. 16, the first switch 111 and the second switch 112 in the pixel in the next row are turned on before writing is completed for the pixel including the sub-pixel 1600a and the sub-pixel 1600b. Therefore, the first liquid crystal element 121 and the second liquid crystal element
The voltage applied to the liquid crystal element 122 changes from the voltage corresponding to the gradation of the pixel. However, as in the case of the pixel configuration in FIG. 6, the pixel in the next row is the sub pixel 1600a.
Since a video signal is written next to the pixel having the sub-pixel 1600b, it becomes a particular problem to set the period during which the third switch 113 is turned on, that is, the latter half of the writing period so that the display is not affected. There is no.

Although FIGS. 13 to 16 show the case where one pixel is composed of sub-pixels having the same structure, the structure may be different between the sub-pixels. Further, although the above description mainly deals with the case where the first switch 111, the second switch 112, and the third switch 113 are controlled using the same scanning line, they are different as shown in FIG. You may control using a scanning line.

As described above, the viewing angle characteristics can be improved by using the present invention. Further, since the liquid crystal display device can be driven without causing a reduction in contrast, it is possible to provide a liquid crystal display device with higher display quality.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. You can freely do such things. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 2)
In this embodiment, an example of a pixel structure which is different from that in Embodiment 1 will be described. The pixel shown in FIG. 19 includes the first switch 111, the second switch 1712, the third switch 113, and the first switch 111.
Resistor 114, second resistor 115, first liquid crystal element 121, second liquid crystal element 122, first resistor
The storage capacitor 131 and the second storage capacitor 132 are included. In addition, the pixel is connected to the signal line 116, the first scan line 117, the second scan line 120, and the Cs line 119.

Note that the on/off of the first switch 111 is turned on/off by the signal input to the first scan line 117, and the on/off of the second switch 1712 and the third switch 113 is turned on/off by the first scan line 117 and the second scan line 120. It is controlled by both signals input to. As described above, the pixel shown in FIG. 19 is different from the pixel structure shown in FIG. 1 in that the second switch 1712 is controlled by signals of both the first scan line 117 and the second scan line 120. Of course, the same reference numerals are used in the drawings and the description thereof is omitted.

Also in the pixel shown in FIG. 19, the first switch 111 is used in the same manner as the pixel shown in FIG.
, The second switch 1712 and the third switch 113 are used to divide the writing period into the first half and the second half.

Note that only when the first switch 111 is turned on by inputting H level to the first scan line 117 and H level is input to both the first scan line 117 and the second scan line 120. The case where the second switch 1712 and the third switch 113 are turned on will be described.

First, in the first half of the writing period, the H level is applied to the first scanning line 117 and the second scanning line 1
The L level is input to 20, and the first switch 111 is turned on. At this time, by turning off the second switch 1712 and the third switch 113, a potential can be quickly supplied to the pixel electrode of the first liquid crystal element 121.

After that, in the latter half of the writing period, the H level is also input to the second scan line 120 to turn on the second switch 1712 and the third switch 113 in addition to the first switch 111. In this way, the signal line 116 and the Cs line 119 that have been electrically disconnected are electrically connected. This makes it possible to quickly adjust the potential supplied to the pixel electrode of the first liquid crystal element 121 in the first half of the writing period to an optimum potential according to the gray scale of the pixel. Further, the pixel electrode of the second liquid crystal element 122 is also supplied with a potential according to the gradation of the pixel.

In this way, the gray scale of the pixel is expressed using the potential difference, that is, the voltage held in the first liquid crystal element 121 and the second liquid crystal element 122. First liquid crystal element 121 and second liquid crystal element 12
Since different voltages are applied in Nos. 2 and 3, the liquid crystals included in each liquid crystal element show different alignments. Therefore, the viewing angle characteristic can be improved. In addition, it becomes possible to quickly write a video signal to a pixel.

Note that the gray scale represented by a pixel is determined by the alignment of liquid crystals included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel; The corresponding potential needs to be determined in consideration of these.

In addition, in FIG. 19 as well, various modes can be used for the first switch 111, the second switch 1712, and the third switch 113, and an electrical switch, a mechanical switch, or the like is applied. can do. That is, it is not limited to a specific one as long as it can control the flow of current. For example, it may be a transistor or a diode, or a logic circuit combining these.

Therefore, as in FIG. 6, as shown in FIG. 20, a second transistor 1722 and a third transistor 613 are used for the second switch 1712 and the third switch 113 in FIG. 19, respectively, and these transistors are turned on. The resistors may be used to realize the first resistor 114 and the second resistor 115 in FIG. 19, and the resistors may be omitted. However, the second transistor 1722 and the third transistor 613 are not connected to the first scan line 117.
And both signals input to the second scan line 120 need to be controlled. Therefore, each of the second transistor 1722 and the third transistor 613 includes two transistors whose gate electrodes are connected to the first scan line 117 and the second scan line 117, respectively.

Further, in order to electrically disconnect the signal line 116 and the Cs line 119 in the first half of the writing period, only the third switch 113 in FIG. 1 in Embodiment 1 and the second switch 113 in FIG.
The switch 1712 and the third switch 113 are used, but the present invention is not limited to this. For example, only the second switch 1712 may be provided as shown in FIG. In this case, the first switch 111 and the third switch 1733 are turned on and off by a signal input to the first scan line 117, and the second switch 1712 is turned on and off by the first scan line 117 and the second scan line 117. It is controlled by both signals input to 120.

In addition, as shown in FIG. 22, a second transistor 1722 and a third transistor 1743 are used for each of the second switch 1712 and the third switch 1733 in FIG. It is also possible to realize the first resistor 114 and the second resistor 115 in 21 and omit these resistors.

Further, the number of liquid crystal elements included in one pixel as described in Embodiment Mode 1 is not particularly limited. For example, as illustrated in FIG. 23, a unit including a transistor 1750, a liquid crystal element 1751, and a storage capacitor 1752 may be further provided between the node 141 and the transistor 1722 in FIG. Note that the switch used for electrically disconnecting the signal line 116 and the Cs line 119 in the first half portion of the writing period is not limited to the transistor 1722 and the transistor 613, and the signal line 116 and the Cs line 119 are formed using a transistor included in the unit. The line 119 may be electrically disconnected.

As described above, the viewing angle characteristics can be improved by using the present invention. Further, since the liquid crystal display device can be driven without causing a reduction in contrast, it is possible to provide a liquid crystal display device with higher display quality.
In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. You can freely do such things. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 3)
In this embodiment, an example of a pixel structure which is different from that in Embodiment 1 will be described. The pixel shown in FIG. 24 includes the switch 111, the transistor 612, the transistor 613, and the first liquid crystal element 1.
21, a second liquid crystal element 122, a first storage capacitor 131, a second storage capacitor 132, and a third storage capacitor 1601. Note that the pixel shown in FIG. 24 includes the signal line 116 and the first scan line 1.
17, the second scan line 120 and the Cs line 119, and is a transistor 62 which is one transistor included in the transistor 613 in the pixel of FIG. 6 described in Embodiment 1.
A third storage capacitor 1901 is provided between one electrode of 0 and the node 142. It is to be noted that the same reference numerals are used commonly in the drawings, and the description thereof will be omitted.

The pixel shown in FIG. 24 can also be operated in the same manner as the pixel shown in FIG. Note that by providing the third storage capacitor 1901, it takes time to reach a potential according to a gray scale to be supplied to the pixel electrode of the second liquid crystal element 122. Therefore, the first liquid crystal element 12
By deliberately slowing the response speed of the liquid crystal included in the second liquid crystal element 122 to which the voltage applied is lower than 1, the viewing angle can be further improved. Even in this case, since the grayscale represented by the pixel is determined by the alignment of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, the potential supplied from the signal line 116 is To be determined.

Further, as shown in FIG. 25, the third storage capacitor 1911 includes a transistor 612 and a node 14
It may be provided between the two. In FIG. 25, the same operation as the pixel shown in FIG. 6 can be performed. Note that as with the pixel shown in FIG. 24, it takes time for the pixel electrode of the second liquid crystal element 122 to reach a potential corresponding to the gray scale to be supplied. By utilizing this, the viewing angle can be further improved. In this case, it is necessary to determine the potential supplied from the signal line 116, taking into consideration that the voltage applied to the second liquid crystal element 122 is determined by capacity division with the third storage capacitor 1911. is there.

Also in the pixel configuration as described above, as in the first embodiment, the gradation represented by the pixel is determined by the alignment of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel. Therefore, the viewing angle can be improved. Further, since the liquid crystal display device can be driven without causing a reduction in contrast, it is possible to provide a liquid crystal display device with higher display quality.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. You can freely do such things. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 4)
In this embodiment mode, an example of a pixel structure which is different from those in Embodiment Modes 1 to 3 will be described. Figure 2
6 includes a switch 111, a transistor 612, a transistor 613, a transistor 1924, a first liquid crystal element 121, a second liquid crystal element 122, a first storage capacitor 131,
The second storage capacitor 132 and the third storage capacitor 1921 are included. Note that the pixel shown in FIG. 26 is connected to the signal line 116, the first scan line 117, the second scan line 120, and the Cs line 119, and further has a transistor in the pixel of FIG. 6 described in Embodiment 1. 1924 and the third
The storage capacitor 1921 is provided. Reference numerals that are the same as those in FIG. 6 are commonly used in the drawings, and description thereof will be omitted.

The third storage capacitor 1921 has a node 142 and a connection point between the node 142 and a wiring which connects the first electrode of the second storage capacitor 132 and the pixel electrode of the second liquid crystal element 122 to each other. It is provided between the node 1922 and the pixel electrode of the second liquid crystal element 122. In addition, the transistor 1924 is provided between the node 1923 and the signal line 116, where a connection point between the third storage capacitor 1921 and the pixel electrode of the second liquid crystal element 122 is a node 1923. That is, the node 1923 is connected to the signal line 116 through the transistor 1924. Like the switch 111, the transistor 612, and the transistor 620, on/off of the transistor 1924 is controlled by a signal input to the first scan line 117.

The pixel shown in FIG. 26 can also be operated similarly to the pixel shown in FIG. Note that in the pixel shown in FIG. 26, potentials are simultaneously supplied to the pixel electrodes of the first liquid crystal element 121 and the second liquid crystal element 122 from the signal line 116 through the switch 111 and the transistor 1924, respectively. Therefore, the potential of the pixel electrode of each liquid crystal element can be quickly adjusted by the optimum potential according to the gradation of the pixel. Therefore, it is effective in high-speed operation. Further, also in the pixel shown in FIG. 26, since the gray scale represented by the pixel is determined by the alignment of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, the viewing angle is improved. be able to. Note that the on resistance of the transistor 1924 is equal to that of the switch 1
It is preferably larger than the on resistance of 11.

As described above, the present invention can improve the viewing angle characteristics. Further, since the liquid crystal display device can be driven without causing a reduction in contrast, it is possible to provide a liquid crystal display device with higher display quality.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. You can freely do such things. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 5)
In this embodiment mode, an example of a pixel structure which is different from those in Embodiment Modes 1 to 4 is described. FIG. 27
The pixel indicated by has a switch 111, a transistor 612, a transistor 613, a first liquid crystal element 121, a second liquid crystal element 122, a first storage capacitor 131, a second storage capacitor 132, and a third storage capacitor 1931. .. Note that the pixel shown in FIG. 27 is connected to the signal line 116, the first scan line 117, the second scan line 120, and the Cs line 119, and further corresponds to the pixel of FIG. 6 shown in Embodiment Mode 1. In this configuration, three storage capacitors 1931 are provided.
Reference numerals that are the same as those in FIG. 2 are commonly used in the drawings, and description thereof will be omitted.

The third storage capacitor 1931 has a node 142 and a node 142 connected to a wiring connecting the first electrode of the second storage capacitor 132 and the pixel electrode of the second liquid crystal element 122. It is provided between the node 1932 and the pixel electrode of the second liquid crystal element 122.

The pixel shown in FIG. 27 can also be operated similarly to the pixel shown in FIG. Note that with the provision of the third storage capacitor 1931, it takes time to reach a potential according to a gray scale to be supplied to the pixel electrode of the second liquid crystal element 122. By utilizing this, the viewing angle can be further improved. In addition, since the voltage applied to the second liquid crystal element 122 is determined by capacity division with the third storage capacitor 1931, it is effective when a small voltage is to be applied to the second liquid crystal element 122.

Also in the pixel according to the present embodiment, since the gradation represented by the pixel is determined by the alignment of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, the viewing angle is improved. be able to.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. You can freely do such things. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 6)
In this embodiment mode, a pixel structure of a display device will be described. In particular, the pixel structure of the liquid crystal display device will be described.

A pixel structure in the case of combining each liquid crystal mode and a transistor will be described with reference to sectional views of the pixel.

Note that as the transistor, a thin film transistor (TFT) including a non-single-crystal semiconductor layer typified by amorphous silicon, polycrystalline silicon, microcrystalline (also referred to as semi-amorphous) silicon, or the like can be used. Further, as a structure of the transistor, a top gate type, a bottom gate type, or the like can be used. Note that a channel-etched type, a channel-protected type, or the like can be used as the bottom-gate transistor.

FIG. 28 is an example of a cross-sectional view of a pixel in the case where a TN method and a transistor are combined.
Features of the pixel structure shown in FIG. 28 will be described.

The liquid crystal molecule 2018 shown in FIG. 28 is an elongated molecule having a long axis and a short axis. here,
The orientation of the liquid crystal molecule 2018 is expressed by the length of the liquid crystal molecule shown in the drawing. That is,
The long axis of the liquid crystal molecule 2018 is parallel to the paper surface (the cross-sectional direction shown in FIG. 28), and the shorter the liquid crystal molecule 2018 is, the longer axis of the liquid crystal molecule 2018 is normal to the paper surface. It is supposed to be close to. The liquid crystal molecule 2018 shown in FIG. 28 is the first substrate 2001.
And the second substrate 2016 are different in the direction of the long axis of the liquid crystal molecules from each other by 90 degrees, and the direction of the long axis of the liquid crystal molecule 2018 located in the middle of these substrates makes them smooth. It is oriented to connect. That is, the liquid crystal molecule 2018 shown in FIG.
The substrate 2001 and the second substrate 2016 are in an orientation state in which they are twisted by 90 degrees.

Note that a case where a bottom-gate transistor including an amorphous semiconductor is used as the transistor will be described. When a transistor including an amorphous semiconductor is used, a large-sized substrate can be used to manufacture a liquid crystal display device at low cost.

The liquid crystal display device has a basic portion called an LCD panel that displays an image. The liquid crystal panel is made by bonding two processed substrates together with a gap of several micrometers.
It is manufactured by injecting a liquid crystal material between the substrates. That is, the liquid crystal is the first substrate and the second substrate.
The substrate is sandwiched between two substrates. In FIG. 28, the liquid crystal 201
1 is sandwiched between the first substrate 2001 and the second substrate 2016. First substrate 200
A transistor and a pixel electrode are formed on the first substrate 1, and the light blocking film 201 is formed on the second substrate 2016.
4, the color filter 2015, the fourth conductive layer 2013, the spacer 2017, and the second alignment film 2012 are formed.

By providing the light-shielding film 2014, a display device with less light leakage when displaying black can be obtained. Note that the light-blocking film 2014 does not need to be particularly formed on the second substrate 2016. When the light-shielding film 2014 is not formed, the number of steps can be reduced, so that manufacturing cost can be reduced and yield can be improved.

Further, the color filter 2015 may not be formed on the second substrate 2016. Even when the color filter 2015 is not formed, the number of steps can be reduced like the light-shielding film, so that manufacturing cost can be reduced and yield can be improved. However,
Even when the color filter 2015 is not formed, a display device capable of color display can be obtained by field sequential driving.

Further, spherical spacers may be scattered instead of the spacer 2017. When the spherical spacers are scattered, the number of steps is reduced, so that the manufacturing cost can be reduced. In addition, the yield can be improved. On the other hand, in the case of forming the spacer 2017, the position of the spacer does not vary, so that the distance between the two substrates can be more easily made constant, and a display device with less display unevenness can be obtained.

Next, processing performed on the first substrate 2001 will be described.

First, the first insulating film 2002 is formed over the first substrate 2001 by a sputtering method, a printing method, a coating method, or the like. The first insulating film 2002 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor. However, when quartz is used as the substrate 2001, the first insulating film 2002 may not be formed.

Next, a first conductive layer 2003 is formed over the first insulating film 2002 by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, a second insulating film 2004 is formed over the entire surface by a sputtering method, a printing method, a coating method, or the like. The second insulating film 2004 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor.

Next, the first semiconductor layer 2005 and the second semiconductor layer 2006 are formed. Note that the first semiconductor layer 2005 and the second semiconductor layer 2006 are successively formed, and their shapes are processed at the same time.

Next, the second conductive layer 2007 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Note that dry etching is preferably used as an etching method performed when the shape of the second conductive layer 2007 is processed. Note that as the second conductive layer 2007, a material having transparency or a material having reflectivity may be used.

Next, a channel region of the transistor is formed. An example of the process will be described. The second semiconductor layer 2006 is etched using the second conductive layer 2007 as a mask. Also,
As the mask, etching may be performed using a mask for processing the shape of the second conductive layer 2007. Then, the first semiconductor layer 2005 in a portion where the second semiconductor layer 2006 is removed becomes a channel region of the transistor. By forming the channel region in this way, the number of masks can be reduced and the manufacturing cost can be reduced.

Next, a third insulating film 2008 is formed, and contact holes are selectively formed in the third insulating film 2008. Note that a contact hole may be formed in the second insulating film 2004 at the same time as forming a contact hole in the third insulating film 2008. Note that the surface of the third insulating film 2008 is preferably as flat as possible. This is because the surface of the third insulating film 2008, which is in contact with the liquid crystal, has unevenness, which affects the alignment of liquid crystal molecules.

Next, a third conductive layer 2009 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, the first alignment film 2010 is formed. Note that after forming the first alignment film 2010, rubbing treatment may be performed in order to control the alignment of liquid crystal molecules.

The first substrate 2001 manufactured as described above, the light blocking film 2014, and the color filter 2015
A second conductive layer 2013, a spacer 2017, and a second alignment film 2012 are formed.
Substrate 2016 with a gap of several micrometers is attached by a sealant. Then, the liquid crystal material is injected between the two substrates. Note that in the TN method, the fourth conductive layer 2013 is formed over the entire surface of the second substrate 2016.

FIG. 29A shows an MVA (Multi-domain Vertical Alignment).
FIG. 3 is an example of a cross-sectional view of a pixel in the case where the ent) method and a transistor are combined. FIG. 29
By applying the pixel structure shown in (A) to the liquid crystal display device of the present invention, the viewing angle can be further increased.

Features of the pixel structure of the MVA liquid crystal panel will be described with reference to the pixel structure shown in FIG. The liquid crystal molecule 2118 shown in FIG. 29A is the liquid crystal molecule 201 shown in FIG.
Similar to 8, it is a slender molecule having a long axis and a short axis. Therefore, also in FIG. 29A, the orientation of the liquid crystal molecule 2118 is expressed by the length of the liquid crystal molecule shown in the drawing. That is, FIG.
The liquid crystal molecules 2118 shown in FIG. 9A are aligned so that the major axis of the liquid crystal molecules 2118 is oriented in the direction normal to the alignment film. In addition, the liquid crystal molecules 2118 in the portion where the alignment control projections 2119 are present are aligned radially around the alignment control projections 2119. In this state, a liquid crystal display device having a wide viewing angle can be obtained.

Note that a case where a bottom-gate transistor including an amorphous semiconductor is used as the transistor will be described. When a transistor including an amorphous semiconductor is used, a large-sized substrate can be used to manufacture a liquid crystal display device at low cost.

In FIG. 29A, the two substrates which sandwich the liquid crystal 2111 correspond to the first substrate 2101 and the second substrate 2116. Note that a transistor and a pixel electrode are formed over the first substrate 2101, and a light-blocking film 2114, a color filter 2115, and a second substrate 2116 are formed over the second substrate 2116.
The fourth conductive layer 2113, the spacer 2117, the second alignment film 2112, and the alignment control protrusion 2119 are formed.

By providing the light-shielding film 2114, a display device with less light leakage when displaying black can be obtained. Note that the light-blocking film 2114 may not be particularly formed on the second substrate 2116. When the light-shielding film 2114 is not formed, the number of steps can be reduced, so that manufacturing cost can be reduced and yield can be improved.

Further, the color filter 2115 may not be formed on the second substrate 2116. Even when the color filter 2115 is not formed, the number of steps can be reduced as in the case of the light-shielding film, so that manufacturing cost can be reduced and yield can be improved. However,
Even when the color filter 2115 is not formed, a display device capable of color display can be obtained by field sequential driving.

Further, spherical spacers may be dispersed instead of the spacer 2117. When the spherical spacers are scattered, the number of steps is reduced, so that the manufacturing cost can be reduced. In addition, the yield can be improved. On the other hand, when the spacer 2117 is formed, the position of the spacer does not vary, so that the distance between the two substrates can be more easily made constant, and a display device with less display unevenness can be obtained.

The processing performed on the first substrate 2101 will be described.

First, the first insulating film 2102 is formed over the first substrate 2101 by a sputtering method, a printing method, a coating method, or the like. The first insulating film 2102 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor. However, when quartz is used as the substrate 2101, the first insulating film 2102 may not be formed.

Next, a first conductive layer 2103 is formed over the first insulating film 2102 by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, a second insulating film 2104 is formed over the entire surface by a sputtering method, a printing method, a coating method, or the like. The second insulating film 2104 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor.

Next, the first semiconductor layer 2105 and the second semiconductor layer 2106 are formed. Note that the first semiconductor layer 2105 and the second semiconductor layer 2106 are successively formed, and their shapes are processed at the same time.

Next, the second conductive layer 2107 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Note that dry etching is preferably used as an etching method performed when the shape of the second conductive layer 2107 is processed. Note that as the second conductive layer 2107, a transparent material or a reflective material may be used.

Next, a channel region of the transistor is formed. An example of the process will be described. The second semiconductor layer 225 is etched using the second conductive layer 2107 as a mask. Alternatively, the mask may be etched using a mask for processing the shape of the second conductive layer 2107. Then, the first semiconductor layer 2105 in a portion where the second semiconductor layer 2106 is removed serves as a channel region of the transistor. By forming the channel region in this way, the number of masks can be reduced and the manufacturing cost can be reduced.

Next, a third insulating film 2108 is formed, and contact holes are selectively formed in the third insulating film 2108. Note that a contact hole may be formed in the second insulating film 2104 at the same time as forming a contact hole in the third insulating film 2108.

Next, a third conductive layer 2109 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, the first alignment film 2110 is formed. Note that after forming the first alignment film 2110, rubbing treatment may be performed in order to control the alignment of the liquid crystal molecules.

The first substrate 2101 manufactured as described above, the light shielding film 2114, and the color filter 2115.
The second conductive layer 2113, the spacer 2117, and the second alignment film 2112 are formed.
Substrate 2116 with a gap of several micrometers is attached by a sealing material. Then, the liquid crystal material is injected between the two substrates.

Note that in the MVA method, the fourth conductive layer 2113 is formed over the entire surface of the second substrate 2116. Further, an alignment control protrusion 2119 is formed in contact with the fourth conductive layer 2113. The orientation control protrusion 2119 preferably has a smooth curved surface. By doing so, alignment defects of the liquid crystal molecules 2118 due to the alignment control protrusions 2119 are reduced. Further, since it is possible to prevent the alignment film formed on the alignment control protrusion 2119 from being broken, it is possible to reduce defects in the alignment film due to the disconnection.

FIG. 29B is a PVA (Patterned Vertical Alignment).
It is an example of a cross-sectional view of a pixel in the case where a method and a transistor are combined. The viewing angle can be further increased by applying the pixel structure shown in FIG. 29B to the liquid crystal display device of the present invention.

Features of the pixel structure illustrated in FIG. 29B are described. Liquid crystal molecule 2 shown in FIG.
Similarly to the liquid crystal molecule 2018 shown in FIG. 28, the liquid crystal molecule 148 in FIG.
The direction of 148 is expressed by the length of liquid crystal molecules shown in the figure. Therefore, FIG.
The liquid crystal molecules 2148 shown in () are aligned such that the major axis of the liquid crystal molecules 2148 is oriented in the direction normal to the alignment film. In addition, the liquid crystal molecules 2148 existing around the electrode cutout portion 2149 where the fourth conductive layer 2143 is not provided are radially aligned around the boundary between the electrode cutout portion 2149 and the fourth conductive layer 2143. In this state, a liquid crystal display device having a wide viewing angle can be obtained.

Note that a case where a bottom-gate transistor including an amorphous semiconductor is used as the transistor will be described. When a transistor including an amorphous semiconductor is used, a large-sized substrate can be used to manufacture a liquid crystal display device at low cost.

In FIG. 29B, the two substrates which sandwich the liquid crystal 2141 correspond to the first substrate 2131 and the second substrate 2146. Note that transistors and pixel electrodes are formed over the first substrate 2131, and a light-blocking film 2144, a color filter 2145, and a second substrate 2146 are formed over the second substrate 2146.
A fourth conductive layer 2143, a spacer 2147, and a second alignment film 2142 are formed.

By providing the light-shielding film 2144, a display device with less light leakage when displaying black can be obtained. Note that the light-blocking film 2144 may not be particularly formed on the second substrate 2146. When the light-shielding film 2144 is not formed, the number of steps can be reduced, so that manufacturing cost can be reduced and yield can be improved.

Further, the color filter 2145 may not be formed on the second substrate 2146. Even when the color filter 2145 is not formed, the number of steps can be reduced as in the case of the light-shielding film, so that manufacturing cost can be reduced and yield can be improved. However,
Even when the color filter 2145 is not formed, a display device capable of color display can be obtained by field sequential driving.

Further, spherical spacers may be scattered instead of the spacers 2147. When the spherical spacers are scattered, the number of steps is reduced, so that the manufacturing cost can be reduced. In addition, the yield can be improved. On the other hand, when the spacers 2147 are formed, the positions of the spacers do not vary, so that the distance between the two substrates can be more easily made constant, and a display device with less display unevenness can be obtained.

The processing performed on the first substrate 2131 will be described.

First, the first insulating film 2132 is formed over the first substrate 2131 by a sputtering method, a printing method, a coating method, or the like. The first insulating film 2132 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor. However,
When quartz is used as the substrate 2131, the first insulating film 2132 may not be formed.

Next, a first conductive layer 2133 is formed over the first insulating film 2132 by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, a second insulating film 2134 is formed over the entire surface by a sputtering method, a printing method, a coating method, or the like. The second insulating film 2134 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor.

Next, the first semiconductor layer 2135 and the second semiconductor layer 2136 are formed. Note that the first semiconductor layer 2135 and the second semiconductor layer 2136 are successively formed, and their shapes are processed at the same time.

Next, the second conductive layer 2137 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Note that dry etching is preferably used as an etching method performed when the shape of the second conductive layer 2137 is processed. Note that as the second conductive layer 2137, a transparent material or a reflective material may be used.

Next, a channel region of the transistor is formed. An example of the process will be described. The second semiconductor layer 2136 is etched using the second conductive layer 2137 as a mask. Also,
As the mask, etching may be performed using a mask for processing the shape of the second conductive layer 2137. Then, the first semiconductor layer 2135 in a portion where the second semiconductor layer 2136 is removed serves as a channel region of the transistor. By forming the channel region in this way, the number of masks can be reduced and the manufacturing cost can be reduced.

Next, a third insulating film 2138 is formed, and contact holes are selectively formed in the third insulating film 2138. Note that a contact hole may be formed in the second insulating film 2134 at the same time as forming a contact hole in the third insulating film 2138.

Next, a third conductive layer 2139 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, the first alignment film 2140 is formed. Note that after forming the first alignment film 2140, rubbing treatment may be performed in order to control the alignment of liquid crystal molecules.

The first substrate 2131 manufactured as described above, the light shielding film 2144, and the color filter 2145.
The fourth conductive layer 2143, the spacer 2147, and the second substrate 2146 on which the second alignment film 2142 is formed are attached to each other with a sealant with a gap of several micrometers. Then, the liquid crystal material is injected between the two substrates.

In the PVA method, the fourth conductive layer 2143 is patterned to form the electrode cutout 2149. The shape of the electrode cutout portion 2149 is not particularly limited, but it is preferable that the electrode cutout portion 2149 is formed by combining a plurality of rectangles having different directions. By doing this,
Since a plurality of regions having different orientations can be formed, a liquid crystal display device having a wide viewing angle can be obtained. The shape of the fourth conductive layer 2143 at the boundary between the electrode cutout portion 2149 and the fourth conductive layer 2143 preferably has a smooth slope with respect to the bottom side. By doing so, alignment defects of the liquid crystal molecules 2148 near the slope are reduced. Further, since it is possible to prevent the alignment film formed on the fourth conductive layer 2143 from breaking, it is possible to reduce defects in the alignment film due to this breaking.

FIG. 30A is an example of a cross-sectional view of a pixel in the case where an IPS (In-Plane-Switching) method and a transistor are combined. The viewing angle can be further increased by applying the pixel structure shown in FIG. 30A to the liquid crystal display device of the present invention.

Features of the pixel structure illustrated in FIG. 30A will be described. Liquid crystal molecule 2 shown in FIG.
Like the liquid crystal molecule 2018 shown in FIG. 28, 248 is an elongated molecule having a long axis and a short axis. Therefore, also in FIG. 30A, the orientation of the liquid crystal molecule 2218 is expressed by the length of the liquid crystal molecule shown in the figure. That is, the liquid crystal molecule 2218 illustrated in FIG. 30A is aligned so that the major axis of the liquid crystal molecule 2218 is always horizontal to the substrate. FIG. 30(A)
The liquid crystal molecules 2 in the state where no electric field is generated in the region where the liquid crystal 2211 exists.
Although the 218 orientation is shown, when an electric field is applied to the liquid crystal molecule 2218, the long axis of the liquid crystal molecule 2218 rotates in a horizontal plane while always maintaining the direction horizontal to the substrate. In this state, a liquid crystal display device having a wide viewing angle can be obtained.

Note that a case where a bottom-gate transistor including an amorphous semiconductor is used as the transistor will be described. When a transistor including an amorphous semiconductor is used, a large-sized substrate can be used to manufacture a liquid crystal display device at low cost.

In FIG. 30A, the two substrates which sandwich the liquid crystal 2211 correspond to the first substrate 2201 and the second substrate 2216. Note that a transistor and a pixel electrode are formed over the first substrate 2201, and a light-blocking film 2214 and a color filter 2215 are formed over the second substrate 2216.
, A spacer 2217, and a second alignment film 2212 are formed.

By providing the light-shielding film 2214, a display device with less light leakage when displaying black can be obtained. Note that the light-blocking film 2214 may not be formed over the second substrate 2216. When the light-shielding film 2214 is not formed, the number of steps can be reduced, so that manufacturing cost can be reduced and yield can be improved.

Further, the color filter 2215 may not be formed on the second substrate 2216. Even when the color filter 2215 is not formed, the number of steps can be reduced like the light-shielding film, so that manufacturing cost can be reduced and yield can be improved. However,
Even when the color filter 2215 is not formed, a display device capable of color display can be obtained by field sequential driving.

Further, spherical spacers may be scattered instead of the spacer 2217. When the spherical spacers are scattered, the number of steps is reduced, so that the manufacturing cost can be reduced. In addition, the yield can be improved. On the other hand, when the spacer 2217 is formed, the position of the spacer does not vary, so that the distance between the two substrates can be more easily made constant, and a display device with less display unevenness can be obtained.

The processing performed on the first substrate 2201 will be described.

First, the first insulating film 2202 is formed over the first substrate 2201 by a sputtering method, a printing method, a coating method, or the like. The first insulating film 2202 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor. However, if quartz is used as the substrate 2201, the first insulating film 2202 may not be formed.

Next, a first conductive layer 2203 is formed over the first insulating film 2202 by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, a second insulating film 2204 is formed over the entire surface by a sputtering method, a printing method, a coating method, or the like. The second insulating film 2204 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor.

Next, the first semiconductor layer 2205 and the second semiconductor layer 2206 are formed. Note that the first semiconductor layer 2205 and the second semiconductor layer 2206 are successively formed, and their shapes are processed at the same time.

Next, the second conductive layer 2207 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Note that dry etching is preferably used as an etching method performed when the shape of the second conductive layer 2207 is processed. Note that as the second conductive layer 2207, a transparent material or a reflective material may be used.

Next, a channel region of the transistor is formed. An example of the process will be described. The second semiconductor layer 2206 is etched using the second conductive layer 2207 as a mask. Also,
The mask may be etched using a mask for processing the shape of the second conductive layer 2207. Then, the first semiconductor layer 2205 in a portion where the second semiconductor layer 2206 is removed serves as a channel region of the transistor. By forming the channel region in this way, the number of masks can be reduced and the manufacturing cost can be reduced.

Next, a third insulating film 2208 is formed, and contact holes are selectively formed in the third insulating film 2208. Note that a contact hole may be formed in the second insulating film 2204 at the same time as forming a contact hole in the third insulating film 2208.

Next, the third conductive layer 2209 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Here, the shape of the third conductive layer 2209 is two comb teeth which are engaged with each other. One comb-tooth-shaped electrode is electrically connected to one of the source electrode and the drain electrode of the transistor, and the other comb-tooth-shaped electrode is electrically connected to the common electrode. By doing so, a horizontal electric field can be effectively applied to the liquid crystal molecules 2218.

Next, the first alignment film 2210 is formed. Note that after forming the first alignment film 2210, rubbing treatment may be performed in order to control the alignment of liquid crystal molecules.

The first substrate 2201 manufactured as described above, the light shielding film 2214, and the color filter 2215.
, The spacer 2217, and the second substrate 2216 on which the second alignment film 2212 is formed are attached to each other with a sealant with a gap of several micrometers. Then, the liquid crystal material is injected between the two substrates.

FIG. 30B is an example of a cross-sectional view of a pixel in the case where a transistor is combined with an FFS (Fringe Field Switching) method. The viewing angle can be further increased by applying the pixel structure shown in FIG. 30B to the liquid crystal display device of the present invention.

Features of the pixel structure illustrated in FIG. 30B are described. Liquid crystal molecule 2 shown in FIG.
248, the liquid crystal molecule 21 is also shown in FIG.
The direction of 48 is expressed by the length of the liquid crystal molecule shown in the figure. Therefore, FIG. 30(B)
The liquid crystal molecules 2248 shown in (2) are oriented so that their major axes are always oriented horizontally with respect to the substrate. In FIG. 30B, the liquid crystal molecule 2248 alignment is shown in a state where no electric field is generated in the region where the liquid crystal 2241 is present. Rotates in the horizontal plane while always maintaining the horizontal direction with respect to the substrate. In this state, a liquid crystal display device having a wide viewing angle can be obtained.

Note that a case where a bottom-gate transistor including an amorphous semiconductor is used as the transistor will be described. When a transistor including an amorphous semiconductor is used, a large-sized substrate can be used to manufacture a liquid crystal display device at low cost.

In FIG. 30B, the two substrates which sandwich the liquid crystal 2241 correspond to the first substrate 2231 and the second substrate 2246. Note that a transistor and a pixel electrode are formed over the first substrate 2241, and a light-blocking film 2244, a color filter 2245, and a second substrate 2246 are formed over the second substrate 2246.
A spacer 2247 and a second alignment film 2242 are formed.

By providing the light-shielding film 2244, a display device with less light leakage when displaying black can be obtained. Note that the light-blocking film 2244 may not be particularly formed on the second substrate 2246. When the light-shielding film 2244 is not formed, the number of steps can be reduced, so that manufacturing cost can be reduced and yield can be improved.

Further, the color filter 2245 may not be formed on the second substrate 2246. Even when the color filter 2245 is not formed, the number of steps can be reduced as in the case of the light-shielding film, so that manufacturing cost can be reduced and yield can be improved. However,
Even when the color filter 2245 is not formed, a display device capable of color display can be obtained by field sequential driving.

Also, spherical spacers may be dispersed instead of the spacers 2247. When the spherical spacers are scattered, the number of steps is reduced, so that the manufacturing cost can be reduced. In addition, the yield can be improved. On the other hand, when the spacer 2247 is formed, the position of the spacer does not vary, so that the distance between the two substrates can be more easily made constant and a display device with less display unevenness can be obtained.

The processing performed on the first substrate 2231 will be described.

First, the first insulating film 2232 is formed over the first substrate 2231 by a sputtering method, a printing method, a coating method, or the like. The first insulating film 2232 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor. However,
When quartz is used as the substrate 2231, the first insulating film 2232 may not be formed.

Next, a first conductive layer 2233 is formed over the first insulating film 2232 by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, a second insulating film 2234 is formed over the entire surface by a sputtering method, a printing method, a coating method, or the like. The second insulating film 2234 has a function of preventing impurities from the substrate from affecting the semiconductor layer and changing the characteristics of the transistor.

Next, the first semiconductor layer 2235 and the second semiconductor layer 2236 are formed. Note that the first semiconductor layer 2235 and the second semiconductor layer 2236 are successively formed, and their shapes are processed at the same time.

Next, the second conductive layer 2237 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Note that dry etching is preferably used as an etching method performed when the shape of the second conductive layer 2237 is processed. Note that a material having transparency or a material having reflectivity may be used for the second conductive layer 2237.

Next, a channel region of the transistor is formed. An example of the process will be described. The second semiconductor layer 2236 is etched using the second conductive layer 2237 as a mask. Also,
The mask may be etched using a mask for processing the shape of the second conductive layer 2237. Then, the first semiconductor layer 2235 in a portion where the second semiconductor layer 2236 is removed serves as a channel region of the transistor. By forming the channel region in this way, the number of masks can be reduced and the manufacturing cost can be reduced.

Next, a third insulating film 2238 is formed, and a contact hole is selectively formed in the third insulating film 2238.

Next, a third conductive layer 2239 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like.

Next, a fourth insulating film 2249 is formed, and contact holes are selectively formed in the fourth insulating film 2249.

Next, the fourth conductive layer 2243 is formed by a photolithography method, a laser direct writing method, an inkjet method, or the like. Here, the shape of the fourth conductive layer 2243 is comb-shaped.

Next, the first alignment film 2240 is formed. Note that after forming the first alignment film 2240, rubbing treatment may be performed in order to control the alignment of liquid crystal molecules.

The first substrate 2231 manufactured as described above, the light shielding film 2244, and the color filter 2245.
, The spacer 2247, and the second substrate 2246 on which the second alignment film 2242 is formed are attached to each other with a sealing material with a gap of several micrometers, and a liquid crystal material is injected between the two substrates, A liquid crystal panel can be manufactured.

Here, materials that can be used for each conductive layer or each insulating film will be described.

The first insulating film 2002 in FIG. 28, the first insulating film 2102 in FIG. 29A, the first insulating film 2132 in FIG. 29B, the first insulating film 2202 in FIG. As the first insulating film 2232 of 30(B), a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (Si
An insulating film such as OxNy) can be used. Further, these insulating films are a silicon oxide film,
An insulating film having a stacked structure in which two or more films of a silicon nitride film, a silicon oxynitride film (SiOxNy), and the like are combined can be used.

The first conductive layer 2003 in FIG. 28, the first conductive layer 2103 in FIG. 29A, the first conductive layer 2133 in FIG. 29B, the first conductive layer 2203 in FIG. For the first conductive layer 2233 of 30(B), a conductive material such as Mo, Ti, Al, Nd, or Cr can be used. In addition, these conductive layers are made of conductive materials such as Mo, Ti, Al, Nd, and Cr.
It is also possible to use a laminated structure in which two or more are combined.

The second insulating film 2004 in FIG. 28, the second insulating film 2104 in FIG. 29A, the second insulating film 2134 in FIG. 29B, the second insulating film 2204 in FIG. As the 30B second insulating film 2234, a thermal oxide film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like can be used. Further, a stacked structure in which two or more of a thermal oxide film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, and the like are combined can be used. Note that the portion in contact with the semiconductor layer is preferably a silicon oxide film. This is because the use of the silicon oxide film reduces the trap level at the interface with the semiconductor layer. It is preferable that the portion in contact with Mo is a silicon nitride film. This is because the silicon nitride film does not oxidize Mo.

The first semiconductor layer 2005 in FIG. 28, the first semiconductor layer 2105 in FIG. 29A, and the first semiconductor layer 2105 in FIG.
The first semiconductor layer 2135 in FIG. 30A, the first semiconductor layer 2205 in FIG. 30A, and the first semiconductor layer 2235 in FIG. 30B can be formed using silicon, silicon germanium (SiGe), or the like. ..

The second semiconductor layer 2006 in FIG. 28, the second semiconductor layer 2106 in FIG. 29A, and the second semiconductor layer 2106 in FIG.
As the second semiconductor layer 2136 of FIG. 30A, the second semiconductor layer 2206 of FIG. 30A, and the second semiconductor layer 2236 of FIG. 30B, silicon containing phosphorus or the like can be used.

The second conductive layer 2007 and the third conductive layer 2009 in FIG. 28, the second conductive layer 2107 and the third conductive layer 2109 in FIG. 29A, the second conductive layer 2137 in FIG. The second conductive layer 2139, the second conductive layer 2207 and the second conductive layer 2209 in FIG. 30A, or the second conductive layer 2237, the third conductive layer 2239, and the fourth in FIG. 30B. Conductive layer 224
Examples of the transparent material 3 include indium tin oxide (ITO) film in which tin oxide is mixed with indium oxide, indium tin silicon oxide (ITSO) film in which silicon oxide is mixed with indium tin oxide (ITO), Indium zinc oxide (zinc oxide mixed with indium oxide)
An IZO) film, a zinc oxide film, a tin oxide film, or the like can be used. IZO is I
It can be formed by sputtering using a target in which TO is mixed with 2 to 20 wt% of zinc oxide (ZnO).

In addition, the second conductive layer 2007 and the third conductive layer 2009 in FIG. 28, the second conductive layer 2107 and the third conductive layer 2109 in FIG. 29A, and the second conductive layer in FIG. 29B. 2137 and the second conductive layer 2139, the second conductive layer 2207 and the second conductive layer 2209 in FIG.
Alternatively, as the reflective material of the second conductive layer 2237, the second conductive layer 2239, and the fourth conductive layer 2243 in FIG. 30B, Ti, Mo, Ta, Cr, W, Al, or the like is used. be able to. Alternatively, a two-layer structure in which Ti, Mo, Ta, Cr, W and Al are laminated,
A three-layer laminated structure in which Al is sandwiched between metals such as Ti, Mo, Ta, Cr and W may be used.

The third insulating film 2008 in FIG. 28, the third insulating film 2108 in FIG. 29A, the third insulating film 2138 in FIG. 29B, the third conductive layer 2139 in FIG. As the third insulating film 2208 of 30(A), the third insulating film 2238 and the fourth insulating film 2249 of FIG. 30(B), an inorganic material (silicon oxide, silicon nitride, silicon oxynitride, etc.) or low An organic compound material having a dielectric constant (photosensitive or non-photosensitive organic resin material) or the like can be used. Alternatively, a material containing siloxane can be used. Note that siloxane is silicon (Si)
Is a material whose skeletal structure is composed of a bond between oxygen and oxygen (O). As a substituent, an organic group containing at least hydrogen (eg, an alkyl group or an aryl group) is used. Alternatively, a fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as the substituent.

The first alignment film 2010 of FIG. 28, the first alignment film 2110 of FIG. 29A, the first alignment film 2140 of FIG. 29B, the first alignment film 2210 of FIG. As the 30(B) first alignment film 2240, a polymer film such as polyimide can be used.

Next, a pixel structure in the case of combining each liquid crystal mode and a transistor will be described with reference to a top view (layout diagram) of the pixel.

The liquid crystal mode includes TN (Twisted Nematic) mode and IPS (Twisted Nematic) mode.
In-Plane-Switching mode, FFS (Fringe Field)
Switching mode, MVA (Multi-domain Vertical)
Alignment mode, PVA (Patterned Vertical Ali)
GMment), ASM (Axially Symmetric aligned Mi)
cro-cell) mode, OCB (Optical Compensated Bir)
fringe mode, FLC (Ferroelectric Liquid)
Crystal mode, AFLC (Anti Ferroelectric Liquid)
d Crystal) or the like can be used.

Note that as the transistor, a thin film transistor (TFT) including a non-single-crystal semiconductor layer typified by amorphous silicon, polycrystalline silicon, microcrystalline (also referred to as semi-amorphous) silicon, or the like can be used.

Note that a top gate type, a bottom gate type, or the like can be used as the structure of the transistor. A channel-etched type, a channel-protected type, or the like can be used as the bottom-gate transistor.

FIG. 31 shows an example of a top view of a pixel in the case where the TN method and a transistor are combined.

The pixel illustrated in FIG. 31 includes a third transistor including a first transistor 2304, a second transistor 2305, a transistor 2320, and a transistor 2321, a first liquid crystal capacitor, a second liquid crystal capacitor, and a first storage capacitor. And a second storage capacitor, which are connected to the first scan line 2300, the second scan line 2301, the signal line 2302, and the Cs line 2311. Note that the equivalent circuit diagram of the pixel configuration illustrated in FIG. 31 is similar to that in FIG. 83, and thus detailed description thereof is omitted.

In FIG. 31, the pixel electrode forming the first liquid crystal capacitor corresponds to the pixel electrode 2307, and the pixel electrode forming the second liquid crystal capacitor corresponds to the pixel electrode 2308. The first storage capacitor includes a capacitor line 2312 connected to the Cs line 2311 outside the pixel portion, a semiconductor layer 2309 connected to the pixel electrode 2307, and an insulating film provided therebetween. ing. Similarly to the first storage capacitor, the second storage capacitor also includes a capacitor line 2312, a semiconductor layer 2310 connected to the pixel electrode 2308, and an insulating film provided therebetween. In addition,
The capacitor line 2312 included in the first storage capacitor and the second storage capacitor includes a transistor 2304.
, A second scan line 2301 including a gate electrode forming a transistor 2321, a second scan line 2301 including a gate electrode forming a transistor 2321, a Cs line 2301, and semiconductor layers 2309 and 2310 include transistors 2304 and 2305. The semiconductor layers including the source region, the drain region, and the channel formation region which form 2320 and 2321 are manufactured in the same step. Further, also for the insulating film forming the first storage capacitor and the second storage capacitor, a film manufactured in the same step as the gate insulating film forming the transistors 2304, 2305, 2320, and 2321 can be used. ..

As shown in FIG. 31, a liquid crystal display device having excellent viewing angle characteristics can be obtained by utilizing two liquid crystal capacitors having different alignment states. The top view shown in FIG. 31 is an example, and the present invention is not limited to this.

Note that in each transistor, the channel width can be increased by having a structure in which one of the source electrode and the drain electrode surrounds the other electrode. Such a structure is particularly effective when an amorphous semiconductor layer having lower mobility than a crystalline semiconductor layer is used for a semiconductor layer of a transistor included in a pixel.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the content (may be part) described in each drawing of this embodiment is applied to or combined with the content (may be part) described in the drawings of other embodiments and examples. , Or replacement can be freely performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each part with parts of another embodiment mode and examples.

Note that in this embodiment, the contents (may be part) described in the other embodiments and examples are
Example of embodying, example of slightly deforming, example of partially changing, example of improving, example of detailed description, example of application, example of related parts And so on. Therefore, the contents described in other embodiment modes and examples can be freely applied to, combined with, or replaced with this embodiment mode.

(Embodiment 7)
In this embodiment mode, various liquid crystal modes are described with reference to cross-sectional views.

32A and 32B are schematic views of a cross section in the TN mode.

A liquid crystal layer 3300 is sandwiched between a first substrate 3301 and a second substrate 3302 which are arranged so as to face each other. A first electrode 3305 is formed on the upper surface of the first substrate 3301. A second electrode 3306 is formed on the upper surface of the second substrate 3302. A first polarizing plate 3303 is provided on the opposite side of the first substrate 3301 from the liquid crystal layer. Second
A second polarizing plate 3304 is arranged on the opposite side of the substrate 3302 from the liquid crystal layer. In addition,
The first polarizing plate 3303 and the second polarizing plate 3304 are arranged so as to be crossed Nicols.

The first polarizing plate 3303 may be provided on the upper surface of the first substrate 3301. The second polarizing plate 3304 may be arranged on the upper surface of the second substrate 3302.

It is sufficient that at least one (or both) of the first electrode 3305 and the second electrode 3306 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 32A is a schematic diagram of a cross section when voltage is applied to the first electrode 3305 and the second electrode 3306 (referred to as a vertical electric field method). Since the liquid crystal molecules are aligned vertically, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Then, the first polarizing plate 3303
Since the second polarizing plate 3304 and the second polarizing plate 3304 are arranged in crossed Nicols, the light from the backlight cannot pass through the substrate. Therefore, black display is performed.

FIG. 32B is a schematic diagram of a cross section when voltage is not applied to the first electrode 3305 and the second electrode 3306. Liquid crystal molecules are arranged side by side, and the first electrode 3305 to the second electrode 3
The light from the backlight is affected by the birefringence of the liquid crystal molecules because it is rotated toward 306. Then, since the first polarizing plate 3303 and the second polarizing plate 3304 are arranged so as to be crossed Nicols, light from the backlight passes through the substrate. Therefore, white display is performed. This is the so-called normally white mode.

By controlling the voltage applied to the first electrode 3305 and the second electrode 3306, the state of the liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure shown in FIGS. 32A and 32B can perform full-color display by being provided with a color filter. The color filter can be provided on the first substrate 3301 side or the second substrate 3302 side.

A known liquid crystal material may be used for the TN mode.

33A and 33B are schematic views of a cross section in the VA mode. The VA mode is a mode in which liquid crystal molecules are aligned so as to be perpendicular to the substrate when no electric field is applied.

A liquid crystal layer 3400 is sandwiched between a first substrate 3401 and a second substrate 3402 which are arranged so as to face each other. A first electrode 3405 is formed on the upper surface of the first substrate 3401. A second electrode 3406 is formed on the upper surface of the second substrate 3402. A first polarizing plate 3403 is provided on the opposite side of the first substrate 3401 from the liquid crystal layer. Second
A second polarizing plate 3404 is arranged on the opposite side of the substrate 3402 from the liquid crystal layer. In addition,
The first polarizing plate 3403 and the second polarizing plate 3404 are arranged so as to be crossed Nicols.

The first polarizing plate 3403 may be provided on the upper surface of the first substrate 3401. The second polarizing plate 3404 may be arranged on the upper surface of the second substrate 3402.

It is sufficient that at least one (or both) of the first electrode 3405 and the second electrode 3406 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 33A is a schematic view of a cross section when voltage is applied to the first electrode 3405 and the second electrode 3406 (referred to as a vertical electric field method). Since the liquid crystal molecules are arranged side by side, the light from the backlight is affected by the birefringence of the liquid crystal molecules. Further, since the first polarizing plate 3403 and the second polarizing plate 3404 are arranged so as to be crossed Nicols, light from the backlight passes through the substrate. Therefore, white display is performed.

FIG. 33B is a schematic view of a cross section when voltage is not applied to the first electrode 3405 and the second electrode 3406. Since the liquid crystal molecules are aligned vertically, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Further, since the first polarizing plate 3403 and the second polarizing plate 3404 are arranged so as to be crossed Nicols, light from the backlight does not pass through the substrate. Therefore, black display is performed. This is the so-called normally black mode.

By controlling the voltage applied to the first electrode 3405 and the second electrode 3406, the state of the liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure shown in FIGS. 34A and 34B can perform full-color display by being provided with a color filter. The color filter can be provided on the first substrate 3401 side or the second substrate 3402 side.

A known material may be used as the liquid crystal material used in the VA mode.

33C and 33D are schematic views of cross sections in the MVA mode. The MVA mode is a method of mutually compensating for the viewing angle dependence of each part.

A liquid crystal layer 3410 is sandwiched between a first substrate 3411 and a second substrate 3412 which are arranged so as to face each other. A first electrode 3415 is formed on the upper surface of the first substrate 3411. A second electrode 3416 is formed on the upper surface of the second substrate 3412. A first protrusion 3417 is formed over the first electrode 3415 for orientation control. A second protrusion 3418 is formed over the second electrode 3416 for orientation control. A first polarizing plate 3413 is provided on the opposite side of the first substrate 3411 from the liquid crystal layer. Second substrate 3
A second polarizing plate 3414 is provided on the opposite side of the liquid crystal layer 412. Note that the first polarizing plate 3413 and the second polarizing plate 3414 are arranged so as to be crossed Nicols.

The first polarizing plate 3413 may be provided on the upper surface of the first substrate 3411. The second polarizing plate 3414 may be provided on the upper surface of the second substrate 3412.

It is sufficient that at least one (or both) of the first electrode 3415 and the second electrode 3416 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 33C is a schematic view of a cross section when voltage is applied to the first electrode 3415 and the second electrode 3416 (referred to as a vertical electric field method). The light from the backlight is affected by the birefringence of liquid crystal molecules. Since the first polarizing plate 3413 and the second polarizing plate 3414 are arranged so as to be crossed Nicols, light from the backlight passes through the substrate. Therefore, white display is performed. In addition, the liquid crystal molecules have a first protrusion 3417 and a second protrusion 341.
8 and is in a state in which the first protrusion 3417 and the second protrusion 3418 are tilted and aligned. Therefore, the viewing angle can be further improved.

FIG. 33D is a schematic view of a cross section when voltage is not applied to the first electrode 3415 and the second electrode 3416. Since the liquid crystal molecules are aligned vertically, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Since the first polarizing plate 3413 and the second polarizing plate 3414 are arranged in a crossed Nicols state, light from the backlight does not pass through the substrate. Therefore, black display is performed. This is the so-called normally black mode.

Note that by controlling the voltage applied to the first electrode 3415 and the second electrode 3416, the state of the liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure shown in FIGS. 36C and 36D can perform full-color display by being provided with a color filter. The color filter can be provided on the first substrate 3411 side or the second substrate 3412 side.

A known material may be used as the liquid crystal material used in the MVA mode.

34A and 34B are schematic views of a cross section in the OCB mode. In the OCB mode, the alignment of liquid crystal molecules in the liquid crystal layer forms an optically compensated state, so that the viewing angle dependency is small. This state of liquid crystal molecules is called bend alignment.

A liquid crystal layer 3500 is sandwiched between a first substrate 3501 and a second substrate 3502 which are arranged so as to face each other. A first electrode 3505 is formed on the upper surface of the first substrate 3501. A second electrode 3506 is formed on the upper surface of the second substrate 3502. A first polarizing plate 3503 is provided on the opposite side of the first substrate 3501 from the liquid crystal layer. Second
A second polarizing plate 336 is arranged on the opposite side of the substrate 3502 from the liquid crystal layer. Note that the first polarizing plate 3503 and the second polarizing plate 336 are arranged so as to be crossed Nicols.

The first polarizing plate 3503 may be provided on the top surface of the first substrate 3501. The second polarizing plate 336 may be arranged on the upper surface of the second substrate 3502.

It is sufficient that at least one (or both) of the first electrode 3505 and the second electrode 3506 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 34A is a schematic diagram of a cross section when voltage is applied to the first electrode 3505 and the second electrode 3506 (referred to as a vertical electric field method). Since the liquid crystal molecules are aligned vertically, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Then, the first polarizing plate 3503
Since the second polarizing plate 336 and the second polarizing plate 336 are arranged in a crossed Nicols state, light from the backlight does not pass through the substrate. Therefore, black display is performed.

FIG. 34B is a schematic view of a cross section when voltage is not applied to the first electrode 3505 and the second electrode 3506. Since the liquid crystal molecules are in the bend alignment state, the light from the backlight is affected by the birefringence of the liquid crystal molecules. Since the first polarizing plate 3503 and the second polarizing plate 336 are arranged so as to be in a crossed Nicols state, light from the backlight passes through the substrate. Therefore, white display is performed. This is the so-called normally white mode.

Note that the state of the liquid crystal molecules, that is, the alignment can be controlled by controlling the voltage applied to the first electrode 3505 and the second electrode 3506. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure shown in FIGS. 34A and 34B can perform full-color display by being provided with a color filter. The color filter can be provided on the first substrate 3501 side or the second substrate 3502 side.

A known liquid crystal material may be used for the OCB mode.

34C and 34D are schematic cross-sectional views of the FLC mode or the AFLC mode.

A liquid crystal layer 3510 is sandwiched between a first substrate 3511 and a second substrate 3512 which are arranged so as to face each other. A first electrode 3515 is formed on the upper surface of the first substrate 3511. A second electrode 3516 is formed on the upper surface of the second substrate 3512. A first polarizing plate 3513 is provided on the opposite side of the first substrate 3511 from the liquid crystal layer. Second
A second polarizing plate 3514 is provided on the opposite side of the substrate 3512 from the liquid crystal layer. In addition,
The first polarizing plate 3513 and the second polarizing plate 3514 are arranged so as to be crossed Nicols.

The first polarizing plate 3513 may be provided on the top surface of the first substrate 3511. The second polarizing plate 3514 may be provided on the upper surface of the second substrate 3512.

It is sufficient that at least one (or both) of the first electrode 3515 and the second electrode 3516 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 34C is a schematic view of a cross section when voltage is applied to the first electrode 3515 and the second electrode 3516 (referred to as a vertical electric field method). Since the liquid crystal molecules are laterally aligned in a direction deviated from the rubbing direction, the light from the backlight is affected by the birefringence of the liquid crystal molecules. Then, since the first polarizing plate 3513 and the second polarizing plate 3514 are arranged so as to be crossed Nicols, light from the backlight passes through the substrate. Therefore, white display is performed.

FIG. 34D is a schematic view of a cross section when voltage is not applied to the first electrode 3515 and the second electrode 3516. Since the liquid crystal molecules are arranged side by side along the rubbing direction, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Then, the first polarizing plate 3
The light from the backlight does not pass through the substrate because the 513 and the second polarizing plate 3514 are arranged so as to be crossed Nicols. Therefore, black display is performed. This is the so-called normally black mode.

Note that the state of the liquid crystal molecules, that is, the alignment can be controlled by controlling the voltage applied to the first electrode 3515 and the second electrode 3516. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure illustrated in FIGS. 34C and 34D can perform full-color display by being provided with a color filter. The color filter can be provided on the first substrate 3511 side or the second substrate 3512 side.

As the liquid crystal material used for the FLC mode or the AFLC mode, known materials may be used.

35(A) and 35(B) are schematic views of a cross section in the IPS mode. The IPS mode is a mode in which liquid crystal molecules are always rotated in a plane with respect to a substrate, and an in-plane switching system in which electrodes are provided only on one substrate side is adopted.

A liquid crystal layer 3600 is sandwiched between a first substrate 3601 and a second substrate 3602 which are arranged so as to face each other. A first electrode 3605 and a second electrode 3606 are formed on the top surface of the first substrate 3601. A first polarizing plate 3603 is provided on the opposite side of the first substrate 3601 from the liquid crystal layer. A second polarizing plate 3604 is provided on the opposite side of the second substrate 3602 from the liquid crystal layer. Note that the first polarizing plate 3603 and the second polarizing plate 3604 are arranged so as to be crossed Nicols.

The first polarizing plate 3603 may be provided on the top surface of the first substrate 3601. The second polarizing plate 3604 may be provided on the upper surface of the second substrate 3602.

It is sufficient that at least one (or both) of the first electrode 3605 and the second electrode 3606 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 35A is a schematic diagram of a cross section when voltage is applied to the first electrode 3605 and the second electrode 3606. Since the liquid crystal molecules are aligned along the lines of electric force deviated from the rubbing direction, the light from the backlight is affected by the birefringence of the liquid crystal molecules. Since the first polarizing plate 3603 and the second polarizing plate 3604 are arranged so as to be in a crossed Nicols state, light from the backlight passes through the substrate. Therefore, white display is performed.

FIG. 35B is a schematic view of a cross section when voltage is not applied to the first electrode 3605 and the second electrode 3606. Since the liquid crystal molecules are arranged side by side along the rubbing direction, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Then, the first polarizing plate 3
The light from the backlight does not pass through the substrate because the 603 and the second polarizing plate 3604 are arranged so as to be crossed Nicols. Therefore, black display is performed. This is the so-called normally black mode.

By controlling the voltage applied to the first electrode 3605 and the second electrode 3606, the state of liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure shown in FIGS. 35A and 35B can perform full-color display by providing a color filter. The color filter can be provided on the first substrate 3601 side or the second substrate 3602 side.

A known liquid crystal material may be used for the IPS mode.

35C and 35D are schematic views of cross sections in the FFS mode. The FFS mode is also a mode in which liquid crystal molecules are always rotated in a plane with respect to the substrate, and an in-plane switching system in which electrodes are provided only on one substrate side is adopted.

A liquid crystal layer 3610 is sandwiched between a first substrate 3611 and a second substrate 3612 which are arranged so as to face each other. A second electrode 3616 is formed on the upper surface of the first substrate 3611. An insulating film 3617 is formed on the upper surface of the second electrode 3616. A second electrode 3616 is formed over the insulating film 3617. A first polarizing plate 3613 is provided on the opposite side of the first substrate 3611 from the liquid crystal layer. A second polarizing plate 3614 is provided on the opposite side of the second substrate 3612 from the liquid crystal layer. Note that the first polarizing plate 3613 and the second polarizing plate
The polarizing plate 3614 and the polarizing plate 3614 are arranged so as to form a crossed Nicols.

The first polarizing plate 3613 may be provided on the upper surface of the first substrate 3611. The second polarizing plate 3614 may be provided on the upper surface of the second substrate 3612.

It is sufficient that at least one (or both) of the first electrode 3615 and the second electrode 3616 has a light-transmitting property (transmissive or reflective). Alternatively, both electrodes may be translucent, and part of one electrode may be reflective (semi-transmissive type).

FIG. 35C is a schematic view of a cross section when voltage is applied to the first electrode 3615 and the second electrode 3616. Since the liquid crystal molecules are aligned along the lines of electric force deviated from the rubbing direction, the light from the backlight is affected by the birefringence of the liquid crystal molecules. Further, since the first polarizing plate 3613 and the second polarizing plate 3614 are arranged so as to be crossed Nicols, light from the backlight passes through the substrate. Therefore, white display is performed.

FIG. 35D is a schematic view of a cross section when voltage is not applied to the first electrode 3615 and the second electrode 3616. Since the liquid crystal molecules are arranged side by side along the rubbing direction, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Then, the first polarizing plate 3
The light from the backlight does not pass through the substrate because 613 and the second polarizing plate 3614 are arranged so as to be crossed Nicols. Therefore, black display is performed. This is the so-called normally black mode.

Note that by controlling the voltage applied to the first electrode 3615 and the second electrode 3616, the state of the liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

The liquid crystal display device having the structure shown in FIGS. 35C and 35D can perform full-color display by being provided with a color filter. The color filter can be provided on the first substrate 3611 side or the second substrate 3612 side.

A known liquid crystal material may be used for the FFS mode.

Next, various liquid crystal modes will be described using a top view.

FIG. 36 shows a top view of one of a plurality of liquid crystal capacitors included in a pixel to which the MVA mode is applied.

FIG. 36 shows a first electrode 3701, a second electrode (3702a, 3702b, 3702c),
And a protrusion 3703 are shown. The first electrode 3701 is formed over the entire surface of the counter substrate. The second electrodes (3702a, 3702b, 3702c) are shaped so that they have a V shape.
) Has been formed. The second electrode (3702a, 3702b, 3702c) is formed on the first electrode 3701 so that the shape corresponds to that of the second electrode (3702a, 3702b, 3702c).
) Has been formed.

The openings of the second electrodes (3702a, 3702b, 3702c) function like protrusions.

When a voltage is applied to the first electrode 3701 and the second electrode (3702a, 3702b, 3702c) (referred to as a vertical electric field method), liquid crystal molecules are applied to the second electrode (3702a, 3702b,
The opening 3702c) and the protrusion 3703 are tilted and aligned. Therefore, it is possible to improve the viewing angle. Note that when the pair of polarizing plates are arranged in a crossed Nicols state, white light is displayed because light from the backlight passes through the substrate.

When no voltage is applied to the first electrode 3701 and the second electrode (3702a, 3702b, 3702c), liquid crystal molecules are vertically aligned. When the pair of polarizing plates are arranged so as to be crossed Nicols, the light from the backlight does not pass through the panel,
Black display is performed. This is the so-called normally black mode.

Note that the state of the liquid crystal molecules, that is, the alignment can be controlled by controlling the voltage applied to the first electrode 3701 and the second electrode (3702a, 3702b, 3702c).
Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

A known material may be used as the liquid crystal material used in the MVA mode.

37(A), (B), (C), and (D) show top views of one liquid crystal capacitor to which the IPS mode is applied. The IPS mode is a mode in which liquid crystal molecules are always rotated in a plane with respect to a substrate, and an in-plane switching system in which electrodes are provided only on one substrate side is adopted.

In the IPS mode, the pair of electrodes are formed to have different shapes.

FIG. 37A illustrates the first electrode 3801 and the second electrode 3802. The first electrode 3801 and the second electrode 3802 have a wavy shape.

FIG. 37B illustrates the first electrode 3811 and the second electrode 3812. The first electrode 3811 and the second electrode 3812 each have a shape having concentric openings.

FIG. 37C illustrates the first electrode 3831 and the second electrode 3832. The first electrode 3831 and the second electrode 3832 are comb-shaped and partially overlap with each other.

FIG. 37D illustrates the first electrode 3841 and the second electrode 3842. The first electrode 3841 and the second electrode 3842 are comb-shaped and have a shape such that the electrodes are engaged with each other.

The first electrode (3801, 3811, 3821, 3831) and the second electrode (3802, 3)
812, 3822, 3832), the liquid crystal molecules are aligned along the lines of electric force deviated from the rubbing direction. When the pair of polarizing plates are arranged in a crossed Nicols state, white light is displayed because light from the backlight passes through the substrate.

The first electrode (3801, 3811, 3821, 3831) and the second electrode (3802, 3)
812, 3822, 3832), when no voltage is applied, the liquid crystal molecules are aligned horizontally along the rubbing direction. When the pair of polarizing plates are arranged in a crossed Nicols state, the light from the backlight does not pass through the substrate, so that black display is performed. It is the so-called normally black mode.

Note that by controlling the voltage applied to the first electrode and the second electrode, the state of liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

A known liquid crystal material may be used for the IPS mode.

38A, 38B, 38C, and 38D are top views of one liquid crystal capacitor to which the FFS mode is applied. The FFS mode is a mode in which liquid crystal molecules are always rotated in a plane with respect to a substrate, and an in-plane switching system in which electrodes are provided only on one substrate side is adopted.

In the FFS mode, the first electrode is formed on the upper surface of the second electrode so as to have various shapes.

FIG. 38A illustrates the first electrode 3901 and the second electrode 3902. The first electrode 3901 has a bent dogleg shape. The second electrode 3902 does not have to be patterned.

FIG. 38B illustrates the first electrode 3911 and the second electrode 3912. The first electrode 3911 has a concentric circular shape. The second electrode 3912 does not have to be patterned.

FIG. 38C illustrates the first electrode 3931 and the second electrode 3932. The first electrode 3931 has a comb field shape and has a shape in which the electrodes are engaged with each other. The second electrode 3932 need not be patterned.

FIG. 38D illustrates the first electrode 3941 and the second electrode 3942. The first electrode 3941 has a comb-like shape. The second electrode 3942 need not be patterned.

The first electrode (3901, 3911, 3921, 3931) and the second electrode (3902, 3
912, 3922, 3932), the liquid crystal molecules are aligned along the lines of electric force deviated from the rubbing direction. When the pair of polarizing plates are arranged in a crossed Nicols state, white light is displayed because light from the backlight passes through the substrate.

The first electrode (3901, 3911, 3921, 3931) and the second electrode (3902, 3
912, 3922, 3932), when no voltage is applied, the liquid crystal molecules are aligned horizontally along the rubbing direction. When the pair of polarizing plates are arranged in a crossed Nicols state, the light from the backlight does not pass through the substrate, so that black display is performed. It is the so-called normally black mode.

Note that by controlling the voltage applied to the first electrode and the second electrode, the state of liquid crystal molecules, that is, the alignment can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, it is possible to display a predetermined image.

A known liquid crystal material may be used for the IPS mode.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the content (may be part) described in each drawing of this embodiment is applied to or combined with the content (may be part) described in the drawings of other embodiments and examples. , Or replacement can be freely performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each part with parts of another embodiment mode and examples.

Note that in this embodiment, the contents (may be part) described in the other embodiments and examples are
Example of embodying, example of slightly deforming, example of partially changing, example of improving, example of detailed description, example of application, example of related parts And so on. Therefore, the contents described in other embodiment modes and examples can be freely applied to, combined with, or replaced with this embodiment mode.

(Embodiment 8)
In the present embodiment, the peripheral portion of the liquid crystal panel will be described.

FIG. 39 shows a backlight unit 2601 called an edge light type and a liquid crystal panel 26.
07 shows an example of a liquid crystal display device including The edge light type is a system in which a light source is arranged at the end of the backlight unit and the light emission of the light source is emitted from the entire light emitting surface. The edge light type backlight unit is thin and can save power.

The backlight unit 2601 includes a diffusion plate 2602, a light guide plate 2603, a reflection plate 2604,
It is composed of a lamp reflector 2605 and a light source 2606.

The light source 2606 has a function of emitting light as needed. For example, as the light source 2606, a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL or an organic EL is used. The lamp reflector 2605 has a function of efficiently guiding light emitted from the light source 2606 to the light guide plate 2603. The light guide plate 2603 has a function of totally reflecting the light from the light source 2603 and guiding the light to the entire surface. The diffusion plate 2602 has a function of reducing unevenness in brightness. The reflector 2604 is
It has a function of reflecting light leaking from the light guide plate 2603 in the opposite direction from the liquid crystal panel 2603 and reusing it.

A control circuit for adjusting the luminance of the light source 2606 is connected to the backlight unit 2601. With this control circuit, the brightness of the light source 2606 can be adjusted.

40(A), (B), (C), and (D) are diagrams showing a detailed configuration of the edge light type backlight unit. The description of the diffusion plate, the light guide plate, the reflection plate, etc. is omitted.

A backlight unit 2701 illustrated in FIG. 40A has a structure in which a cold cathode tube 2703 is used as a light source. A lamp reflector 2702 is provided in order to efficiently reflect the light from the cold cathode tube 2703. Such a structure is often used for a large display device.

A backlight unit 2711 shown in FIG. 40B includes a light emitting diode (LE) as a light source.
D) 2713 is used. For example, a white light emitting diode (W) 2713
Are arranged at predetermined intervals. A lamp reflector 2712 is provided to efficiently reflect the light from the light emitting diode 2713.

Since the light emitting intensity of the light emitting diode is high, the structure using the light emitting diode is suitable for a large-sized display device. Further, since the light emitting diode has excellent color reproducibility, it is possible to display an image faithful to the input image information. Further, since the light emitting diode is small, the arrangement area can be reduced. Therefore, the frame of the display device can be narrowed.

When the light emitting diode is mounted on a large-sized display device, the light emitting diode can be arranged on the back surface of the substrate. The light emitting diodes maintain a predetermined distance, and the light emitting diodes of each color are sequentially arranged.

A backlight unit 2721 shown in FIG. 40C includes a light-emitting diode (LED) 2723 for each color of RGB, a light-emitting diode (LED) 2724, and a light-emitting diode (LE) as a light source.
D) 2725 is used. The light emitting diode 2723 (LED) of each color of RGB, the light emitting diode (LED) 2724, and the light emitting diode (LED) 2725 are arranged at predetermined intervals. By using the light emitting diode (LED) 2723 of each color of RGB, the light emitting diode (LED) 2724, and the light emitting diode (LED) 2725, color reproducibility can be improved. Further, a lamp reflector 2722 is provided in order to efficiently reflect the light from the light emitting diode.

Since the brightness of the light emitting diode is high, the configuration using the light emitting diode of each color of RGB as a light source is suitable for a large-sized display device. Further, since the light emitting diode has excellent color reproducibility, it is possible to display an image faithful to the input image information. Further, since the light emitting diode is small, the arrangement area can be reduced. Therefore, the frame of the display device can be narrowed.

Note that color display can be performed by sequentially lighting the RGB light emitting diodes in accordance with time. It can be displayed in the so-called field sequential mode.

It should be noted that a light emitting diode that emits white light and a light emitting diode (LED) 2723 for each color of RGB are provided.
The light emitting diode (LED) 2724 and the light emitting diode (LED) 2725 can be combined.

When the light emitting diode is mounted on a large-sized display device, the light emitting diode can be arranged on the back surface of the substrate. In addition, each of the light emitting diodes maintains a predetermined interval, and the light emitting diodes of each color are sequentially arranged. With such an arrangement, color reproducibility can be improved.

A backlight unit 2731 illustrated in FIG. 40D includes a light-emitting diode (LED) 2733, a light-emitting diode (LED) 2734, and a light-emitting diode (LE) as light sources, which are RGB colors.
D) 2735 is used. For example, a light emitting diode (LED) 27 for each color of RGB
33, a light emitting diode (LED) 2734, and a light emitting diode (LED) 2735 having a color (for example, green) having a low light emission intensity, and a plurality of light emitting diodes (LED) 2734 are arranged in FIG. 40D. With such a configuration, color reproducibility can be further enhanced. Further, a lamp reflector 2732 is provided in order to efficiently reflect the light from the light emitting diode.

Since the light emitting intensity of the light emitting diode is high, the configuration using the light emitting diode of each color of RGB as a light source is suitable for a large-sized display device. Further, since the light emitting diode has excellent color reproducibility, it is possible to display an image faithful to the input image information. Further, since the light emitting diode is small, the arrangement area can be reduced. Therefore, the frame of the display device can be narrowed.

Note that color display can be performed by sequentially lighting the RGB light emitting diodes in accordance with time.

In addition, a light emitting diode that emits white light and a light emitting diode (LED) 2733 for each color of RGB
, A light emitting diode (LED) 2734, and a light emitting diode (LED) 2735 can be combined.

When the light emitting diode is mounted on a large-sized display device, the light emitting diode can be arranged on the back surface of the substrate. Each of the light emitting diodes maintains a predetermined interval, and light emitting diodes of respective colors are sequentially arranged. With such an arrangement, color reproducibility can be improved.

FIG. 41A shows a backlight unit 2800 called a direct type and a liquid crystal panel 280.
5 shows an example of a liquid crystal display device having The direct type is a system in which a light source is arranged immediately below a light emitting surface, and the light emitted from the light source is emitted from the entire light emitting surface. The direct type backlight unit can efficiently utilize the emitted light amount.

The backlight unit 2800 includes a diffusion plate 2801, a light blocking plate 2802, a lamp reflector 2803, and a light source 2804.

The light source 2804 has a function of emitting light as needed. For example, as the light source 2805, a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL or an organic EL is used. The lamp reflector 2803 efficiently emits light emitted from the light source 2804 and the diffusion plate 2801 and the light shielding plate 2
It has a function of leading to 802. The light-blocking plate 2802 has a function of reducing unevenness in brightness by increasing the light-blocking in a place where the light intensity is strong according to the arrangement of the light source 2804. Diffuser 2801
Has a function of further reducing unevenness in brightness.

A control circuit for adjusting the brightness of the light source 2804 is connected to the backlight unit 2800. The brightness of the light source 2804 can be adjusted by this control circuit.

FIG. 41B shows a backlight unit 3015 called a direct type and a liquid crystal panel 301.
An example of a liquid crystal display device having 0 and 0 is shown.

The backlight unit 2810 includes a diffusion plate 2811, a light shielding plate 2812, a lamp reflector 2813, a light source (R) 2814a for each color of RGB, a light source (G) 2814b, and a light source (B)2.
814c.

The light sources 2814a (R), the light sources 2814b (G), and the light sources 2814c (B) for each of the RGB colors have a function of emitting light as necessary. For example, the light source 2814a(R), the light source 2814b
As (G) and the light source 2814c(B), a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL or an organic EL is used. The lamp reflector 2813 has a function of efficiently guiding the light emitted from the light source 2814 to the diffusion plate 2811 and the light shielding plate 2812. The shading plate 2812 is
In accordance with the arrangement of the light source 2814, the more light is blocked, the more light is blocked, so that the unevenness in brightness is reduced. The diffusion plate 2811 has a function of further reducing unevenness in brightness.

The backlight unit 2810 includes a light source 2814a(R) for each color of RGB, a light source 2
A control circuit for adjusting the brightness of the light source 814b (G) and the light source 2814c (B) is connected. With this control circuit, the light sources 2814a(R), 2814b(G)
) And the brightness of the light source 2814c(B) can be adjusted.

FIG. 42 is a diagram showing an example of the configuration of a polarizing plate (also referred to as a polarizing film).

The polarizing film 2900 includes a protective film 2901, a substrate film 2902, a PVA polarizing film 2903, a substrate film 2904, an adhesive layer 2905, and a release film 2906.

The PVA polarizing film 2903 has a function of converting light into light in only a certain vibration direction (linearly polarized light). Specifically, the PVA polarizing film 2903 contains molecules (polarizers) having electron densities greatly different in the vertical and horizontal directions. The PVA polarizing film 2903 in which the directions of molecules in which the electron densities greatly differ from each other in the vertical and horizontal directions are aligned makes it possible to obtain linearly polarized light.

As an example, the PVA polarizing film 2903 is made of polyvinyl alcohol (Poly Vin).
A polymer film of yl Alcohol) is doped with an iodine compound and the PVA film is pulled in a certain direction to obtain a film in which iodine molecules are arranged in a certain direction. Then, the light parallel to the long axis of the iodine molecule is absorbed by the iodine molecule. A dichroic dye may be used in place of iodine for high durability and high heat resistance. The dye is
It is suitable for liquid crystal display devices that require durability and heat resistance, such as vehicle-mounted LCDs and projector LCDs.

Further, the PVA polarizing film 2903 is a film (substrate film 290) whose both sides are base materials.
2 and the substrate film 2904), the reliability can be increased. Also, PVA
The polarizing film 2903 may be sandwiched between triacetylose (TAC) films having high transparency and high durability. Such substrate film and TAC film are
It functions as a protective layer for the polarizer of the VA polarizing film 2903.

The substrate film (substrate film 2904) has an adhesive layer 2905 attached to the glass substrate of the liquid crystal panel. The pressure-sensitive adhesive layer 2905 is formed by applying a pressure-sensitive adhesive to the substrate film (substrate film 2904) on one side. The pressure-sensitive adhesive layer 2905 is provided with a release film 2906 (separate film).

A protective film 2901 is provided on the other substrate film (substrate film 2902).

A hard coat scattering layer (anti-glare layer) may be provided on the surface of the polarizing film 2900. Since the hard coat scattering layer has fine irregularities formed on the surface by the AG treatment and has an antiglare function for scattering external light, reflection of external light on the liquid crystal panel can be prevented. Therefore, surface reflection can be prevented.

In addition, a plurality of optical thin film layers having different refractive indices may be multilayered (also referred to as anti-reflection treatment or AR treatment) on the surface of the polarizing film 2900. The plurality of multilayered optical thin film layers having different refractive indexes can reduce the reflectance of the surface due to the light interference effect.

FIG. 43 is a diagram showing an example of a system block of the liquid crystal display device.

As shown in FIG. 43A, in the pixel portion 3005, the signal line 3012 is provided with the signal line driver circuit 300.
3 is stretched and arranged. Further, the scan line 3010 is arranged so as to extend from the scan line driver circuit 3004. Then, a plurality of pixels are arranged in a matrix in an intersection region between the signal line 3012 and the scan line 3010. Note that each of the plurality of pixels has a switching element, and the details of the pixel portion 3005 are described in the above embodiment and thus are omitted here.

In FIG. 43A, the driver circuit portion 3008 includes a control circuit 3002 and a signal line driver circuit 30.
03 and a scan line driver circuit 3004. The video signal 3001 is input to the control circuit 3002. The control circuit 3002 responds to the control signal 3001 by the signal line drive circuit 30.
03 and the scanning line drive circuit 3004. Therefore, the control circuit 3002 inputs respective control signals to the signal line driver circuit 3003 and the scan line driver circuit 3004. Then, in accordance with this control signal, the signal line driver circuit 3003 inputs a video signal to the signal line 3012,
The scan line driver circuit 3004 inputs a scan signal to the scan line 3010. Then, the switching element included in the pixel is selected according to the scan signal, and the video signal is input to the pixel electrode of the pixel.

The control circuit 3002 also controls the power supply 3007 according to the control signal 3001. The power supply 3007 has a means for supplying electric power to the lighting means 3006. Lighting means 30
As 06, an edge light type backlight unit or a direct type backlight unit can be used. Further, a front light may be used as the lighting means 3006. The front light is a plate-shaped light unit that is mounted on the front surface side of the pixel portion and that illuminates the entire body and is composed of a light-emitting body and a light guide body. With such an illumination means, the pixel portion can be illuminated uniformly with low power consumption.

The scan line driver circuit 3004 includes, for example, a shift register 3041 and a shift register 3041, as shown in FIG.
It has a circuit functioning as a level shifter 3042 and a buffer 3043. Signals such as a gate start pulse (GSP) and a gate clock signal (GCK) are input to the shift register 3041 from the control circuit 2902.

As illustrated in FIG. 43C, the signal line driver circuit 3003 includes circuits functioning as a shift register 3031, a first latch 3032, a second latch 3033, a level shifter 3034, and a buffer 3035. The circuit functioning as the buffer 3035 is a circuit having a function of amplifying a weak signal and includes an operational amplifier or the like. The level shifter 3034 receives signals such as a start pulse (SSP) and a source clock signal (SCK) from the first latch 303.
Data (DATA) such as a video signal is input to 2. Latch (LAT) signals can be temporarily held in the second latch 3033 and are input to the pixel portion 3005 all at once. This is called line-sequential driving. Therefore, if the pixel performs dot-sequential driving instead of line-sequential driving,
The second latch may be unnecessary.

In the present embodiment, a known liquid crystal panel can be used. For example, as the liquid crystal panel, a structure in which a liquid crystal layer is sealed between two substrates can be used.
A transistor, a capacitor, a pixel electrode, an alignment film, or the like is formed over one substrate. A polarizing plate, a retardation plate or a prism sheet may be arranged on the side opposite to the upper surface of the substrate. A color filter, a black matrix, a counter electrode, an alignment film, or the like is formed on the other substrate. A polarizing plate or a retardation plate may be arranged on the side opposite to the upper surface of the other substrate. The color filter and the black matrix may be formed on the upper surface of one of the substrates. Note that three-dimensional display can be performed by arranging a slit (grating) on the upper surface side of one substrate or on the opposite side.

It should be noted that the polarizing plate, the retardation plate and the prism sheet can be respectively arranged between the two substrates. Alternatively, it can be integrated with either of the two substrates.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the content (may be part) described in each drawing of this embodiment is applied to or combined with the content (may be part) described in the drawings of other embodiments and examples. , Or replacement can be freely performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each part with parts of another embodiment mode and examples.

Note that in this embodiment, the contents (may be part) described in the other embodiments and examples are
Example of embodying, example of slightly deforming, example of partially changing, example of improving, example of detailed description, example of application, example of related parts And so on. Therefore, the contents described in other embodiment modes and examples can be freely applied to, combined with, or replaced with this embodiment mode.

(Embodiment 9)
In this embodiment, a method of driving the display device will be described. In particular, a method of driving the liquid crystal display device will be described.

A liquid crystal panel that can be used in the liquid crystal display device described in this embodiment has a structure in which a liquid crystal material is sandwiched between two substrates. Each of the two substrates is provided with an electrode for controlling an electric field applied to the liquid crystal material. The liquid crystal material is a material whose optical and electrical properties are changed by an electric field applied from the outside. Therefore, the liquid crystal panel
It is a device in which desired optical and electrical properties can be obtained by controlling a voltage applied to a liquid crystal material using an electrode included in a substrate. Then, by arranging a large number of electrodes side by side on a plane, each of which serves as a pixel, and by individually controlling the voltage applied to the pixel, a liquid crystal panel capable of displaying a fine image can be obtained.

Here, the response time of the liquid crystal material to the change of the electric field is the space between two substrates (cell gap).
Although it depends on the type of liquid crystal material and the like, it is generally several milliseconds to several tens of milliseconds. Furthermore, when the amount of change in the electric field is small, the response time of the liquid crystal material becomes longer. This property causes obstacles in image display such as afterimage, trailing, and deterioration of contrast when displaying a moving image by the liquid crystal panel, and particularly when changing from a halftone to another halftone (change of electric field). Is small), the degree of the above-mentioned obstacle becomes significant.

On the other hand, as a problem peculiar to a liquid crystal panel using an active matrix, there is a change in writing voltage due to constant charge driving. The constant charge driving in this embodiment will be described below.

The pixel circuit in the active matrix includes a switch for controlling writing and a capacitor element for holding electric charge. A driving method of a pixel circuit in an active matrix is to turn on a switch and write a predetermined voltage to the pixel circuit, and then immediately turn off the switch to hold electric charges in the pixel circuit (hold state). In the hold state, charges are not exchanged between the inside and outside of the pixel circuit (constant charge). Normally, the period in which the switch is off is several hundreds (the number of scanning lines) times longer than the period in which the switch is on. Therefore, it can be considered that the switch of the pixel circuit is almost off.
From the above, it is assumed that the constant charge driving in the present embodiment is a driving method in which the pixel circuit is in the hold state for most of the period when the liquid crystal panel is driven.

Next, the electrical characteristics of the liquid crystal material will be described. When the electric field applied from the outside changes, the liquid crystal material changes its optical properties as well as its dielectric constant. That is, when each pixel of the liquid crystal panel is considered as a capacitive element (liquid crystal element) sandwiched by two electrodes, the capacitive element is a capacitive element whose electrostatic capacitance changes according to an applied voltage. This phenomenon is called dynamic capacitance.

As described above, when the capacitive element whose capacitance changes according to the applied voltage is driven by the above-mentioned constant charge driving, the following problems occur. That is, there is a problem that when the capacitance of the liquid crystal element changes in the hold state in which charges are not moved, the applied voltage also changes. This can be understood from the fact that the charge amount is constant in the relational expression of (charge amount)=(electrostatic capacity)×(applied voltage).

For the above reason, in the liquid crystal panel using the active matrix, the voltage in the hold state changes from the voltage in the writing due to the constant charge driving. As a result, the transmittance of the liquid crystal element is different from the change in the driving method that does not take the hold state. FIG. 44 shows this state. FIG. 44A shows an example of controlling the voltage to be written in the pixel circuit, in which the horizontal axis represents time and the vertical axis represents the absolute value of the voltage. FIG. 44B shows an example of controlling the voltage to be written in the pixel circuit when time is plotted on the horizontal axis and voltage is plotted on the vertical axis. In FIG. 44C, the horizontal axis represents time and the vertical axis represents the transmittance of the liquid crystal element,
44A shows the change over time in the transmittance of the liquid crystal element when the voltage shown in FIG. 44A or 44B is written in the pixel circuit. In FIGS. 44A to 44C, a period F represents a voltage rewriting cycle, and the time of rewriting the voltage is t ₁ , t ₂ , t ₃ , t ₄ ,.
・ Explain as.

Here, the writing voltage corresponding to the image data input to the liquid crystal display device is |V ₁ | for rewriting at time 0, and | for rewriting at times t ₁ , t ₂ , t ₃ , t ₄ ,...
Let V ₂ |. (See FIG. 44(A))

The polarities of the write voltage corresponding to the image data input to the liquid crystal display device may be periodically changed. (Reverse driving: see FIG. 44B) By this method, it is possible to prevent application of a DC voltage to the liquid crystal as much as possible, so that burn-in or the like due to deterioration of the liquid crystal element can be prevented. The cycle of switching the polarities (reversal cycle) may be the same as the voltage rewriting cycle. In this case, since the inversion cycle is short, the occurrence of flicker due to the inversion drive can be reduced. Further, the inversion period may be a period that is an integral multiple of the voltage rewriting period. In this case, the inversion period is long, and the frequency of writing the voltage by changing the polarity can be reduced, so that the power consumption can be reduced.

Then, FIG. 44C shows a change over time in the transmittance of the liquid crystal element when a voltage as shown in FIG. 44A or FIG. 44B is applied to the liquid crystal element. Here, the voltage |V ₁ is applied to the liquid crystal element.
Let TR _{1 be} the transmittance of the liquid crystal element after | is applied and a sufficient time has elapsed. Similarly, the voltage |V ₂ | is applied to the liquid crystal element and the transmittance of the liquid crystal element after a sufficient time has passed is TR ₂ . At time t ₁ , when the voltage applied to the liquid crystal element changes from |V ₁ | to |V ₂ |, the transmittance of the liquid crystal element does not immediately become TR ₂ as indicated by a broken line 30401, Change slowly. For example, when the voltage rewriting cycle is the same as the frame cycle (16.7 milliseconds) of the image signal of 60 Hz, it takes about several frames until the transmittance changes to TR ₂ .

However, the smooth change in transmittance with time as shown by a broken line 30401 is when the voltage |V ₂ | is accurately applied to the liquid crystal element. In an actual liquid crystal panel, for example, a liquid crystal panel using an active matrix, the voltage in the hold state changes from the voltage in writing due to the constant charge driving, and therefore the transmittance of the liquid crystal element is broken line 30401. The time change does not occur as shown in, but instead, it becomes a stepwise time change as shown by the solid line 30402. This is because the voltage changes due to the constant charge driving, and thus the target voltage cannot be reached by writing once. As a result, the response time of the transmittance of the liquid crystal element is apparently longer than the original response time (broken line 30401), and the obstruction in image display such as afterimage, tailing, and deterioration of contrast becomes remarkable. It will cause it.

By using the overdrive driving, it is possible to simultaneously solve the original length of the response time of the liquid crystal element and the phenomenon that the apparent response time is further lengthened due to insufficient writing due to the dynamic capacitance and constant charge driving. FIG. 45 shows this state. In FIG. 45A, a horizontal axis represents time and a vertical axis represents an absolute value of a voltage, and a control example of a voltage written in a pixel circuit is illustrated. FIG. 45B shows an example of controlling the voltage to be written in the pixel circuit when the horizontal axis represents time and the vertical axis represents voltage. In FIG. 45C, the horizontal axis represents time and the vertical axis represents the transmittance of the liquid crystal element, and the liquid crystal element of the liquid crystal element when the voltage represented in FIG. 45A or 45B is written in the pixel circuit. It shows the change over time in the transmittance. In FIGS. 45A to 45C, the period F represents a voltage rewriting cycle, and the time when the voltage is rewritten will be described as t ₁ , t ₂ , t ₃ , t ₄ ,....

Here, the writing voltage corresponding to the image data input to the liquid crystal display device is |V ₁ | for rewriting at time 0, |V ₃ | for rewriting at time t ₁ , and times t ₂ , t ₃ , t.
It is assumed that |V ₂ | is used for rewriting at ₄ ,... (See FIG. 45(A))

The polarities of the write voltage corresponding to the image data input to the liquid crystal display device may be periodically changed. (Reverse driving: see FIG. 45(B)) By this method, it is possible to prevent application of a DC voltage to the liquid crystal as much as possible, so that burn-in or the like due to deterioration of the liquid crystal element can be prevented. The cycle of switching the polarities (reversal cycle) may be the same as the voltage rewriting cycle. In this case, since the inversion cycle is short, the occurrence of flicker due to the inversion drive can be reduced. Further, the inversion period may be a period that is an integral multiple of the voltage rewriting period. In this case, the inversion period is long, and the frequency of writing the voltage by changing the polarity can be reduced, so that the power consumption can be reduced.

Then, FIG. 45C shows a change over time in the transmittance of the liquid crystal element when a voltage as shown in FIG. 45A or 45B is applied to the liquid crystal element. Here, the voltage |V ₁ is applied to the liquid crystal element.
Let TR _{1 be} the transmittance of the liquid crystal element after | is applied and a sufficient time has elapsed. Similarly, the voltage |V ₂ | is applied to the liquid crystal element and the transmittance of the liquid crystal element after a sufficient time has passed is TR ₂ . Similarly, the voltage |V ₃ | is applied to the liquid crystal element, and the transmittance of the liquid crystal element after a sufficient time has passed is TR ₃ . At time t ₁ , the voltage applied to the liquid crystal element changes from |V ₁ | to |V
_When it changes to ₃ |, the transmittance of the liquid crystal element tends to change to TR ₃ over several frames, as indicated by a broken line 30501. However, the voltage | _{V 3} | applied at the end at time _{t 2,} later than time _{t 2,} the voltage | _{V 2} | is applied. Therefore, the transmittance of the liquid crystal element is not as shown by the broken line 30501 but as shown by the solid line 30502. here,
It is preferable to set the value of the voltage |V ₃ | so that the transmittance is approximately TR ₂ at the time t ₂ . Here, the voltage |V ₃ | is also referred to as an overdrive voltage.

That is, by changing the overdrive voltage |V ₃ |, the response time of the liquid crystal element can be controlled to some extent. This is because the response time of liquid crystal changes depending on the strength of the electric field. Specifically, the stronger the electric field, the shorter the response time of the liquid crystal element, and the weaker the electric field, the longer the response time of the liquid crystal element.

The overdrive voltage |V ₃ | is preferably changed according to the amount of change in voltage, that is, the voltages |V ₁ | and |V ₂ | that give the desired transmittances TR ₁ and TR _2. .. This is because even if the response time of the liquid crystal element changes depending on the amount of change in the voltage, if the overdrive voltage |V ₃ | is changed accordingly, the optimum response time can always be obtained. is there.

The overdrive voltage |V ₃ | is preferably changed according to the liquid crystal mode such as TN, VA, IPS, or OCB. The reason is that even if the response speed of the liquid crystal varies depending on the mode of the liquid crystal, if the overdrive voltage |V ₃ | is changed accordingly, an optimum response time can always be obtained.

The voltage rewriting cycle F may be the same as the frame cycle of the input signal. In this case, since the peripheral drive circuit of the liquid crystal display device can be simplified, a liquid crystal display device with a low manufacturing cost can be obtained.

The voltage rewriting cycle F may be shorter than the frame cycle of the input signal. For example,
The voltage rewriting period F may be 1/2 times, 1/3 times or less than the frame period of the input signal. It is effective to use this method together with the countermeasures against the deterioration of the moving image quality due to the hold driving of the liquid crystal display device, such as black insertion driving, backlight blinking, backlight scanning, and intermediate image insertion driving by motion compensation. is there. That is, as a countermeasure against the deterioration of the moving image quality due to the hold driving of the liquid crystal display device, since the required response time of the liquid crystal element is short, it is relatively easy to use the overdrive driving method described in the present embodiment. Moreover, the response time of the liquid crystal element can be shortened. The response time of the liquid crystal element can be essentially shortened depending on the cell gap, the liquid crystal material, the liquid crystal mode, etc., but it is technically difficult. Therefore, it is very important to use a method such as overdrive that shortens the response time of the liquid crystal element from the driving method.

The voltage rewriting cycle F may be longer than the frame cycle of the input signal. For example,
The voltage rewriting cycle F may be twice, three times, or more than the frame cycle of the input signal. It is effective to use this method together with a means (circuit) for determining whether or not the voltage rewriting is performed for a long period of time. That is, when voltage rewriting is not performed for a long time, the circuit operation can be stopped during the period by not performing the voltage rewriting operation itself, so that a liquid crystal display device with low power consumption can be obtained. You can

Next, a specific method for changing the overdrive voltage |V ₃ | according to the voltages |V ₁ | and |V ₂ | that give the desired transmittances TR ₁ and TR ₂ will be described.

The overdrive circuit is a circuit for appropriately controlling the overdrive voltage |V ₃ | in accordance with the voltages |V ₁ | and |V ₂ | that give the desired transmittances TR ₁ and TR _2. The signal input to the drive circuit is a voltage |V that gives the transmittance TR _1.
The signal related to ₁ | and the signal related to the voltage |V ₂ | that gives the transmittance TR ₂ , and the signal output from the overdrive circuit is a signal related to the overdrive voltage |V ₃ |. Here, these signals include voltages (|V ₁ |, |V ₂ | applied to the liquid crystal element).
, |V ₃ |), or a digital signal for applying a voltage to be applied to the liquid crystal element. Here, it is assumed that the signal related to the overdrive circuit is a digital signal.

First, the overall configuration of the overdrive circuit will be described with reference to FIG. Here, the input image signal 310 is used as a signal for controlling the overdrive voltage.
1a and 3101b are used. As a result of processing these signals, an output image signal 3104 is output as a signal that gives an overdrive voltage.

Here, the voltages |V ₁ | and |V ₂ | that give the desired transmittances TR ₁ and TR ₂ are
Since the image signals are in the adjacent frames, the input image signals 3101a and 3101b are also preferably the image signals in the adjacent frames. In order to obtain such a signal, the input image signal 3101a can be input to the delay circuit 3102 in FIG. 46A and the signal output as a result can be the input image signal 3101b. The delay circuit 3102 may be, for example, a memory. That is,
In order to delay the input image signal 3101a by one frame, the input image signal 3101a is stored in the memory.
101a is stored, and at the same time, the signal stored in the previous frame is extracted from the memory as the input image signal 3101b, and the input image signal 3101a and the input image signal 3101b are input to the correction circuit 3103 at the same time. By doing so, it is possible to handle image signals in adjacent frames. Then, the image signals in the frames adjacent to each other are input to the correction circuit 3103 to output the output image signal 3104.
Can be obtained. Note that when a memory is used as the delay circuit 3102, a memory having a capacity capable of storing an image signal for one frame (that is, a frame memory) can be used for delaying by one frame. By doing this, there is no excess or deficiency of memory capacity,
It can have a function as a delay circuit.

Next, the delay circuit 3102 configured mainly for the purpose of reducing the memory capacity will be described. By using such a circuit as the delay circuit 3102, the capacity of the memory can be reduced, so that manufacturing cost can be reduced.

As the delay circuit 3102 having such characteristics, specifically, a circuit as shown in FIG. 46B can be used. The delay circuit 3102 shown in FIG.
105, a memory 3106, and a decoder 3107.

The operation of the delay circuit 3102 shown in FIG. 46(B) is as follows. First,
Before storing the input image signal 3101a in the memory 3106, the encoder 3105 performs compression processing. This can reduce the size of data to be stored in the memory 3106. As a result, the capacity of the memory can be reduced, and the manufacturing cost can be reduced. Then, the image signal that has been subjected to the compression processing is decoded by the decoder 3107.
And the decompression process is performed here. As a result, the signal before being compressed by the encoder 3105 can be restored. Here, the compression/expansion processing performed by the encoder 3105 and the decoder 3107 may be reversible processing. By doing so, since the image signal is not deteriorated even after the compression/expansion processing, the capacity of the memory can be reduced without deteriorating the quality of the image finally displayed on the device. Furthermore, the compression/expansion process performed by the encoder 3105 and the decoder 3107 may be an irreversible process. By doing so, the size of the compressed image signal data can be made extremely small, and the memory capacity can be greatly reduced.

As a method for reducing the memory capacity, various methods can be used other than those mentioned above. Instead of compressing the image with an encoder, reduce the color information of the image signal (for example, reduce from 260,000 colors to 65,000 colors) or reduce the number of data (reduce the resolution). Any method can be used.

Next, a specific example of the correction circuit 3103 will be described with reference to FIGS. The correction circuit 3103 is a circuit for outputting an output image signal having a certain value from the two input image signals. Here, when the relationship between the two input image signals and the output image signal is non-linear and it is difficult to obtain by simple calculation, a look-up table (LUT) may be used as the correction circuit 3103. Since the relationship between two input image signals and output image signals has been obtained in advance in the LUT by measurement, the output image signals corresponding to the two input image signals can be obtained only by referring to the LUT. (See (C) of FIG. 46) By using the LUT 3108 as the correction circuit 3103, the correction circuit 3103 can be realized without performing a complicated circuit design or the like.

Since the LUT is one of the memories, it is preferable to reduce the memory capacity as much as possible in order to reduce the manufacturing cost. As an example of the correction circuit 3103 for realizing this, the circuit shown in FIG. 46D can be considered. The correction circuit 3103 shown in (D) of FIG.
It has an LUT 3109 and an adder 3110. The LUT 3109 has an input image signal 310.
1a and the difference data of the output image signal 3104 to be output are stored. That is, from the input image signal 3101a and the input image signal 3101b, the corresponding difference data is LUT.
3109, and the extracted difference data and the input image signal 3101a are added to the adder 31.
By adding with 10, the output image signal 3104 can be obtained. LUT
By making the data stored in 3109 the difference data, the memory capacity of the LUT can be reduced. This is because the difference data has a smaller data size than the output image signal 3104 as it is, and thus the memory capacity required for the LUT 3109 can be reduced.

Furthermore, if the output image signal is obtained by a simple operation such as four arithmetic operations of two input image signals, it can be realized by a combination of simple circuits such as an adder, a subtractor, and a multiplier.
As a result, it is not necessary to use the LUT, and the manufacturing cost can be significantly reduced.
As such a circuit, the circuit shown in FIG. 46E can be given. 46 (
The correction circuit 3103 shown in E) includes a subtractor 3111, a multiplier 3112, and an adder 3113.
With. First, the subtracter 3111 calculates the difference between the input image signal 3101a and the input image signal 3101b. After that, the multiplier 3112 multiplies the difference value by an appropriate coefficient. Then, the difference value obtained by multiplying the input image signal 3101a by an appropriate coefficient is added to the adder 311.
An output image signal 3104 can be obtained by adding 3 to each other. By using such a circuit, it is not necessary to use the LUT, and the manufacturing cost can be significantly reduced.

Note that by using the correction circuit 3103 illustrated in FIG. 46E under certain conditions,
It is possible to prevent the inappropriate output image signal 3104 from being output. The conditions are
That is, there is linearity in the difference value between the output image signal 3104 that gives the overdrive voltage and the input image signal 3101a and the input image signal 3101b. Then, the gradient of this linearity is used as a coefficient to be multiplied by the multiplier 3112. That is, it is preferable to use the correction circuit 3103 shown in FIG. 46E for a liquid crystal element having such a property. As a liquid crystal element having such a property, there is an IPS mode liquid crystal element having a small gray scale dependence of response speed. As described above, for example, by using the correction circuit 3103 shown in FIG. 46E for the liquid crystal element in the IPS mode, it is possible to significantly reduce the manufacturing cost and output an inappropriate output image signal 3104. An overdrive circuit that can be prevented can be obtained.

The functions equivalent to those of the circuits shown in FIGS. 46A to 46E may be realized by software processing. As the memory used for the delay circuit, other memory included in the liquid crystal display device, memory included in a device that sends out an image to be displayed on the liquid crystal display device (for example, a video card included in a personal computer or a device similar thereto), and the like are included. Can be diverted. By doing so, not only the manufacturing cost can be reduced, but also the strength of overdrive, the situation of use, and the like can be selected by the user.

Next, driving for operating the potential of the common line will be described with reference to FIG. 47 (
A) shows a plurality of pixel circuits when one common line is arranged for one scanning line in a display device using a display element having a capacitive property such as a liquid crystal element. It is a figure. The pixel circuit illustrated in FIG. 47A includes a transistor 3201, an auxiliary capacitor 3202, a display element 3203, a video signal line 3204, a scan line 3205, and a common line 3206.

A gate electrode of the transistor 3201 is electrically connected to the scan line 3205, one of a source electrode and a drain electrode of the transistor 3201 is electrically connected to a video signal line 3204, and the other of the source electrode and the drain electrode of the transistor 3201 is connected. Is the auxiliary capacity 3202
One electrode of the display element 3203 and one electrode of the display element 3203 are electrically connected.
The other electrode of the auxiliary capacitor 3202 is electrically connected to the common line 3206.

First, in the pixel selected by the scan line 3205, since the transistor 3201 is turned on, a voltage corresponding to a video signal is applied to the display element 3203 and the auxiliary capacitor 3202 through the video signal line 3204, respectively. At this time, when the video signal is for displaying the lowest gradation for all the pixels connected to the common line 3206, or the common line 3
When the highest gradation is displayed on all the pixels connected to 206, it is not necessary to write the video signal to each pixel via the video signal line 3204. Video signal line 320
The voltage applied to the display element 3203 can be changed by moving the potential of the common line 3206 instead of writing the video signal via the signal line 4.

Next, FIG. 47B shows a case where two common lines are arranged for one scan line in a display device using a display element having a capacitive property such as a liquid crystal element. It is a figure showing a plurality of pixel circuits. The pixel circuit illustrated in FIG. 47B includes a transistor 3211, an auxiliary capacitor 3212, a display element 3213, a video signal line 3214, a scan line 3215, and a first common line 3.
216 and a second common wire 3217.

A gate electrode of the transistor 3211 is electrically connected to the scan line 3215, one of a source electrode and a drain electrode of the transistor 3211 is electrically connected to a video signal line 3214, and the other of the source electrode and the drain electrode of the transistor 3211 is connected. Is the auxiliary capacitance 3212
One electrode and one electrode of the display element 3213 are electrically connected.
The other electrode of the auxiliary capacitor 3212 is electrically connected to the first common line 3216.
Further, in the pixel adjacent to the pixel, the other electrode of the auxiliary capacitor 3212 is electrically connected to the second common line 3217.

In the pixel circuit shown in FIG. 47B, since there are few pixels electrically connected to one common line, instead of writing a video signal through the video signal line 3214, the first common line 3 is used.
By moving the potential of 216 or the second common line 3217, the frequency with which the voltage applied to the display element 3213 can be changed significantly increases. In addition, source inversion drive or dot inversion drive is possible. By source inversion drive or dot inversion drive, flicker can be suppressed while improving the reliability of the element.

Next, the scanning backlight will be described with reference to FIG. 66. FIG. 66A is a diagram showing a scanning backlight in which cold cathode tubes are arranged side by side. The scanning backlight shown in FIG. 66A includes a diffusion plate 6601 and N cold cathode fluorescent lamps 6602-1 to 6602-N. By arranging N cold cathode fluorescent lamps 6602-1 to 6602-N side by side behind the diffusion plate 6601, the N cold cathode fluorescent lamps 6602-1 to 6602-N scan while changing the brightness thereof. You can

The change in the brightness of each cold cathode fluorescent lamp during scanning will be described with reference to FIG. First, the brightness of the cold cathode fluorescent lamp 6602-1 is changed for a certain period of time. Then, after that, the cold cathode tube 660
The brightness of the cold cathode fluorescent lamp 6602-2 arranged next to 2-1 is changed for the same time. In this way, the luminance is changed in order from the cold cathode fluorescent lamps 6602-1 to 6602-N. Note that in FIG. 66C, the luminance changed for a certain period of time is lower than the original luminance, but may be higher than the original luminance. Further, although the cold cathode tubes 6602-1 to 6602-N are scanned, the cold cathode tubes 6602-N to 6602-1 may be scanned in the opposite direction.

By driving as in FIG. 66, the average luminance of the backlight can be reduced. Therefore, the power consumption of the backlight, which accounts for most of the power consumption of the liquid crystal display device, can be reduced.

An LED may be used as the light source of the scanning backlight. The scanning backlight in that case is as shown in FIG. The scanning backlight shown in FIG. 66B includes a diffusion plate 6611 and light sources 6612-1 to 6612-N in which LEDs are arranged in parallel. When an LED is used as the light source of the scanning backlight, there is an advantage that the backlight can be thin and light. Further, there is an advantage that the color reproduction range can be widened. Furthermore, L
Since LEDs arranged in parallel with each of the light sources 6612-1 to 6612-N in which EDs are arranged side by side can be similarly scanned, a point scanning type backlight can also be used. The point scanning type can further improve the image quality of the moving image.

Even when an LED is used as the light source of the backlight, it is possible to drive by changing the brightness as shown in FIG. 66(C).

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. Can be done freely. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 10)
In this embodiment mode, operation of the display device is described.

FIG. 67 is a diagram illustrating a configuration example of a display device.

The display device 6700 includes a pixel portion 6701, a signal line driver circuit 6703, and a scan line driver circuit 67.
Have 04. In the pixel portion 6701, a plurality of signal lines S1 to Sm are provided with a signal line driver circuit 670.
3 is arranged so as to extend in the column direction. The pixel portion 6701 includes a plurality of scan lines G1 to G
n is arranged extending from the scanning line driving circuit 6704 in the row direction. The pixel 670 is provided at the intersection of the plurality of signal lines S1 to Sm and the plurality of scanning lines G1 to Gn.
2 are arranged in a matrix.

Note that the signal line driver circuit 6703 has a function of outputting a signal to each of the signal lines S1 to Sn. This signal may be called a video signal. Note that the scan line driver circuit 6704 has a function of outputting a signal to each of the scan lines G1 to Gm. This signal may be called a scanning signal.

Note that the pixel 6702 has at least a switching element connected to a signal line.
This switching element is controlled to be turned on/off by the potential of the scanning line (scan signal). Then, the pixel 6702 is selected when the switching element is on, and the pixel 6702 is not selected when the switching element is off.

When the pixel 6702 is selected (selected state), a video signal is input to the pixel 6702 from the signal line. Then, the state of the pixel 6702 (for example, luminance, transmittance, voltage of the storage capacitor, or the like) changes depending on the input video signal.

When the pixel 6702 is not selected (non-selected state), the video signal is not input to the pixel 6702. However, since the pixel 6702 holds the potential according to the video signal input at the time of selection, the pixel 6702 maintains the potential according to the video signal (eg, luminance, transmittance, voltage of holding capacitor, or the like).

Note that the structure of the display device is not limited to that in FIG. For example, new wirings (scanning lines, signal lines, power supply lines, capacitance lines, common lines, or the like) may be added depending on the structure of the pixel 6702.
As another example, circuits having various functions may be added.

FIG. 68 shows an example of a timing chart for explaining the operation of the display device.

The timing chart in FIG. 68 shows one frame period corresponding to a period for displaying an image for one screen. One frame period is not particularly limited, but the viewer of the image flickers (flicker)
It is preferable that the time is at least 1/60 second or less so as not to feel

The timing chart of FIG. 68 shows that the scanning line G1 in the first row and the scanning line Gi in the i-th row (scanning line G1
1 to Gm), the timing at which the i+1-th scanning line Gi+1 and the m-th scanning line Gm are respectively selected.

Note that at the same time that the scan line is selected, the pixel 6702 connected to the scan line is also selected. For example, when the i-th scanning line Gi is selected, the pixel 6702 connected to the i-th scanning line Gi is also selected.

Each of the scanning lines G1 to Gm is sequentially selected from the first scanning line G1 to the mth scanning line Gm (hereinafter, also referred to as scanning). For example, while the scanning line Gi on the i-th row is selected, the scanning lines (G1 to Gi-1, Gi+1 to Gm) other than the scanning line Gi on the i-th row are selected.
) Is not selected. Then, in the next period, the scanning line Gi+1 of the i+1th row is selected. Note that a period in which one scan line is selected is referred to as one gate selection period. It is also referred to as a writing period in a row selected for the scan line.

Therefore, when a scan line in a certain row is selected, a plurality of pixels 670 connected to the scan line are selected.
2, a video signal is input from each of the signal lines G1 to Gm. For example, while the scanning line Gi of the i-th row is selected, the plurality of pixels 67 connected to the scanning line Gi of the i-th row
02 inputs arbitrary video signals from the respective signal lines S1 to Sn. In this manner, each of the plurality of pixels 6702 can be independently controlled by the scan signal and the video signal.

Next, a case where one gate selection period is divided into a plurality of sub-gate selection periods will be described.
FIG. 69 shows a timing chart in the case where one gate selection period is divided into two subgate selection periods (first subgate selection period and second subgate selection period).

Note that one gate selection period can be divided into three or more subgate selection periods.

The timing chart in FIG. 69 shows one frame period corresponding to a period for displaying an image for one screen. One frame period is not particularly limited, but the viewer of the image flickers (flicker)
It is preferable that the time is at least 1/60 second or less so as not to feel

Note that one frame has two subframes (first subframe and second subframe).
Is divided into

In the timing chart of FIG. 69, the scanning line Gi on the i-th row and the scanning line Gi+1,j on the i+1-th row are shown.
The timings at which the scanning line Gj of the row (one of the scanning lines Gi+1 to Gm), the scanning line of the j+1 row, and the scanning line Gj+1 of the Gj+1 row are respectively selected are shown.

Note that at the same time that the scan line is selected, the pixel 6702 connected to the scan line is also selected. For example, when the i-th scanning line Gi is selected, the pixel 6702 connected to the i-th scanning line Gi is also selected.

The scanning lines G1 to Gm are sequentially scanned in each sub-gate selection period. For example, in a certain one gate selection period, the i-th scanning line Gi is selected in the first sub-gate selecting period, and the j-th scanning line Gj is selected in the second sub-gate selecting period.
Then, in one gate selection period, it is possible to operate as if scanning signals for two rows were simultaneously selected. At this time, different video signals are input to the signal lines S1 to Sn in the first subgate selection period and the second subgate selection period. Therefore,
Pixels 6702 connected to the i-th row and pixels 670 connected to the j-th row
Different video signals can be input to 2 and 3.

Next, a driving method for converting a frame rate of input image data (also referred to as an input frame rate) and a display frame rate (also referred to as a display frame rate) will be described. The frame rate is the number of frames per second, and the unit is Hz.

In the present embodiment, the input frame rate does not necessarily have to match the display frame rate. When the input frame rate and the display frame rate are different, the frame rate can be converted by a circuit (frame rate conversion circuit) that converts the frame rate of the image data. By doing so, display can be performed at various display frame rates even when the input frame rate and the display frame rate are different.

When the input frame rate is higher than the display frame rate, by discarding a part of the input image data, it is possible to display by converting into various display frame rates.
In this case, since the display frame rate can be reduced, the operating frequency of the drive circuit for displaying can be reduced, and the power consumption can be reduced. On the other hand, when the input frame rate is lower than the display frame rate, all or part of the input image data is displayed multiple times, another image is generated from the input image data, and the input image data is By using means such as generating irrelevant images, it is possible to convert to various display frame rates for display. In this case, the quality of the moving image can be improved by increasing the display frame rate.

In the present embodiment, a frame rate conversion method when the input frame rate is smaller than the display frame rate will be described in detail. The frame rate conversion method when the input frame rate is higher than the display frame rate can be realized by performing the reverse procedure of the frame rate conversion method when the input frame rate is lower than the display frame rate. it can.

In the present embodiment, an image displayed at the same frame rate as the input frame rate is called a basic image. On the other hand, an image displayed at a frame rate different from that of the basic image and displayed to match the input frame rate and the display frame rate is referred to as an interpolated image. The same image as the input image data can be used as the basic image. The same image as the basic image can be used as the interpolation image. Furthermore, an image different from the basic image can be created and the created image can be used as an interpolation image.

When creating an interpolated image, the method of detecting the temporal change (image movement) of the input image data and using the image in the intermediate state as the interpolated image, the image obtained by multiplying the luminance of the basic image by a coefficient Is used as an interpolated image, a plurality of different images are created from the input image data, and the plurality of images are temporally continuously presented (one of the plurality of images is a basic image,
By using the rest as an interpolation image), there is a method of making an observer perceive that an image corresponding to the input image data is displayed. As a method of creating a plurality of different images from the input image data, there are a method of converting a gamma value of the input image data, a method of dividing a gradation value included in the input image data, and the like.

The image in the intermediate state (intermediate image) is an image obtained by detecting a temporal change (image movement) of input image data and interpolating the detected movement. Obtaining an intermediate image by such a method is called motion compensation.

Next, a specific example of the frame rate conversion method will be described. According to this method, it is possible to realize frame rate conversion that is an arbitrary rational number (n/m) times. Here, n and m are integers of 1 or more. The frame rate conversion method according to the present embodiment can be handled by dividing it into a first step and a second step. Here, the first step is a step of converting the frame rate to an arbitrary rational number (n/m) times. Here, a basic image may be used as the interpolation image, or an intermediate image obtained by motion compensation may be used as the interpolation image. In the second step, a plurality of different images (sub-images) are created from the input image data or each image subjected to the frame rate conversion in the first step, and the plurality of sub-images are temporally continuous. This is a step for performing the method of displaying as. By using the method according to the second step, it is possible to make the human eyes perceive as if the original image was displayed, although a plurality of different images are actually displayed.

The frame rate conversion method according to the present embodiment may use both the first step and the second step, may omit the first step and use only the second step, or The second step may be omitted and only the first step may be used.

First, as a first step, frame rate conversion of arbitrary rational number (n/m) times will be described. (See FIG. 70) In FIG. 70, the horizontal axis represents time, and the vertical axis represents various n and m in different cases. The graphic in FIG. 70 represents a schematic diagram of a displayed image, and represents the timing of display depending on its lateral position. Furthermore, it is assumed that the points displayed in the figure schematically represent the movement of the image. However, this is an example for explanation, and the image displayed is not limited to this. This method can be applied to various images.

The period Tin represents the cycle of input image data. The cycle of the input image data corresponds to the input frame rate. For example, when the input frame rate is 60 Hz, the cycle of input image data is 1/60 second. Similarly, if the input frame rate is 50 Hz,
The cycle of the input image data is 1/50 second. Thus, the cycle of the input image data (unit:
Second) is the reciprocal of the input frame rate (unit: Hz). Various input frame rates can be used. For example, 24Hz, 50Hz, 60Hz, 70Hz,
48Hz, 100Hz, 120Hz, 140Hz, etc. can be mentioned. Where 2
4 Hz is a frame rate used for film movies and the like. 50 Hz is a frame rate used for PAL standard video signals and the like. 60 Hz is a frame rate used for NTSC standard video signals and the like. 70 Hz is a frame rate used for a display input signal of a personal computer. 48Hz, 100Hz, 120Hz,
140 Hz is twice the frame rate of these. It should be noted that the frame rate is not limited to double, and various frame rates may be used. As described above, according to the method described in the present embodiment, it is possible to realize frame rate conversion for input signals of various standards.

The procedure of frame rate conversion in the first step that is multiplied by an arbitrary rational number (n/m) is as follows.
As the procedure 1, the k-th interpolation image for the first basic image (k is an integer of 1 or more; the initial value is 1)
) Display timing is determined. It is assumed that the display timing of the k-th interpolation image is the time when a period obtained by multiplying the cycle of the input image data by k (m/n) has elapsed since the first basic image was displayed.
In step 2, it is determined whether the coefficient k(m/n) used to determine the display timing of the kth interpolation image is an integer. If it is an integer, the (k(m/n)+1)th basic image is displayed at the display timing of the kth interpolation image, and the first step ends. If it is not an integer, go to step 3.
As procedure 3, an image to be used as the kth interpolation image is determined. Specifically, the coefficient k(m/n) used for determining the display timing of the kth interpolation image is converted into the form of x+y/n. Here, x and y are integers, and y is a number smaller than n. When the kth interpolation image is an intermediate image obtained by motion compensation, the kth interpolation image is the (x+1)th interpolation image.
) To the (x+2)th basic image, the intermediate image is obtained as an image corresponding to a motion that is (y/n) times the motion of the image. When the kth interpolation image is the same as the basic image, the (x+1)th basic image can be used. A method of obtaining an intermediate image as an image corresponding to a motion obtained by multiplying the motion of the image by (y/n) will be described in detail in another part.
In step 4, the target interpolation image is moved to the next interpolation image. Specifically, the value of k is incremented by 1, and the procedure returns to step 1.

Next, in the procedure in the first step, the values of n and m are specifically shown and described in detail.

The mechanism for executing the procedure in the first step may be implemented in the device or may be predetermined in the design stage of the device. If a mechanism for executing the procedure in the first step is installed in the device, it becomes possible to switch the driving method so that the optimum operation according to the situation is performed. The conditions here include the contents of image data, the environment inside and outside the device (temperature, humidity, atmospheric pressure, light, sound, magnetic field, electric field, radiation dose,
Altitude, acceleration, moving speed, etc.), user settings, software version, etc. On the other hand, if the mechanism for executing the procedure in the first step is predetermined in the design stage of the device, the optimum driving circuit for each driving method can be used, and the mechanism is determined. As a result, a reduction in manufacturing cost due to the effect of mass production can be expected.

When n=1, m=1, that is, when the conversion ratio (n/m) is 1 (where n=1, m=1 in FIG. 70), the operation in the first step is as follows. First, when k=1, in Procedure 1, the display timing of the first interpolation image with respect to the first basic image is determined. The display timing of the first interpolation image is the cycle of the input image data after the first basic image is displayed, k(m
/N) times, that is, the time when a period of 1 time has passed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the first interpolation image is an integer. Here, since the coefficient k(m/n) is 1, it is an integer. Therefore, at the display timing of the first interpolation image, the (k(m/n)+1)th, that is, the second basic image is displayed, and the first step is ended.

That is, when the conversion ratio is 1, the k-th image is the basic image, the k+1-th image is the basic image, and the image display cycle is one time the cycle of the input image data. To do.

As a concrete expression, when the conversion ratio is 1 (n/m=1),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
A method for driving a display device, which sequentially displays the (k+1)th image and an input image data cycle at equal intervals.
The k-th image is displayed according to the i-th image data,
The k+1th image is displayed according to the i+1th image data.

Here, when the conversion ratio is 1, the frame rate conversion circuit can be omitted, so that there is an advantage that the manufacturing cost can be reduced. Furthermore, when the conversion ratio is 1, there is an advantage that the quality of the moving image can be improved more than when the conversion ratio is smaller than 1. Further, when the conversion ratio is 1, there is an advantage that the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 1.

When n=2 and m=1, that is, when the conversion ratio (n/m) is 2 (where n=2 and m=1 in FIG. 70), the operation in the first step is as follows. First, when k=1, in Procedure 1, the display timing of the first interpolation image with respect to the first basic image is determined. The display timing of the first interpolation image is the cycle of the input image data after the first basic image is displayed, k(m
/N) times, that is, the time when a period of 1/2 times has elapsed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the first interpolation image is an integer. Here, since the coefficient k(m/n) is 1/2, it is not an integer. Therefore, the procedure proceeds to step 3.

In procedure 3, the image used as the first interpolation image is determined. Therefore, the coefficient 1/2 is x
Convert to +y/n form. When the coefficient is 1/2, x=0 and y=1. When the first interpolation image is an intermediate image obtained by motion compensation, the first interpolation image is the (x+
1) That is, the motion of the image from the first basic image to the (x+2), that is, the second basic image is an intermediate image obtained as an image corresponding to a motion of y/n times, that is, 1/2 times. First
When the interpolation image of 1 is the same as the basic image, the (x+1)th, that is, the first basic image can be used.

With the procedure up to this point, the display timing of the first interpolation image and the image to be displayed as the first interpolation image could be determined. Next, in procedure 4, the target interpolation image is moved from the first interpolation image to the second interpolation image. That is, k is changed from 1 to 2, and the procedure returns to step 1.

When k=2, in procedure 1, the display timing of the second interpolation image with respect to the first basic image is determined. The display timing of the second interpolation image is the time when a period in which the cycle of the input image data has been multiplied by k (m/n), that is, one time has elapsed since the first basic image was displayed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the second interpolation image is an integer. Here, since the coefficient k(m/n) is 1, it is an integer. Therefore, at the display timing of the second interpolation image, the (k(m/n)+1)th, that is, the second basic image is displayed, and the first step is ended.

That is, when the conversion ratio is 2 (n/m=2),
The kth image is the basic image,
The k+1st image is an interpolated image,
The (k+2)th image is a basic image, and the image display period is half the period of the input image data.

As a concrete expression, when the conversion ratio is 2 (n/m=2),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
A method of driving a display device, which sequentially displays the k+2th image and an input image data cycle at intervals of 1/2 times,
The k-th image is displayed according to the i-th image data,
The k+1st image is displayed according to image data corresponding to a movement obtained by halving the movement from the i-th image data to the i+1-th image data,
The k+2nd image is displayed according to the i+1th image data.

As another more specific expression, when the conversion ratio is 2 (n/m=2),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
A method of driving a display device, which sequentially displays the k+2th image and an input image data cycle at intervals of 1/2 times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i+1th image data.

Specifically, when the conversion ratio is 2, it is also called double speed drive or simply double speed drive.
For example, if the input frame rate is 60 Hz, the display frame rate is 120 Hz(
120 Hz drive). Then, the image is displayed twice consecutively for one input image. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. Further, when the display device is an active matrix type liquid crystal display device,
A particularly remarkable image quality improving effect is brought about. This is related to the problem of insufficient write voltage due to so-called dynamic capacitance, in which the electrostatic capacity of the liquid crystal element changes depending on the applied voltage. That is, by increasing the display frame rate higher than the input frame rate, it is possible to increase the frequency of the image data writing operation, so that it is possible to reduce troubles such as trailing of moving images and afterimages due to insufficient writing voltage due to dynamic capacitance. be able to. Further, it is also effective to combine the AC drive and the 120 Hz drive of the liquid crystal display device. That is, by setting the drive frequency of the liquid crystal display device to 120 Hz and setting the frequency of the AC drive to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 240 Hz, etc.), the flicker that appears due to the AC drive is reduced. It can be reduced to a level not perceived by the human eye.

When n=3, m=1, that is, when the conversion ratio (n/m) is 3 (where n=3, m=1 in FIG. 70), the operation in the first step is as follows. First, when k=1, in Procedure 1, the display timing of the first interpolation image with respect to the first basic image is determined. The display timing of the first interpolation image is the cycle of the input image data after the first basic image is displayed, k(m
/N) times, that is, the time when a period of 1/3 times has elapsed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the first interpolation image is an integer. Here, the coefficient k(m/n) is 1/3 and is not an integer. Therefore, the procedure proceeds to step 3.

In procedure 3, the image used as the first interpolation image is determined. Therefore, the coefficient 1/3 is x
Convert to +y/n form. When the coefficient is 1/3, x=0 and y=1. When the first interpolation image is an intermediate image obtained by motion compensation, the first interpolation image is the (x+
1) That is, the motion of the image from the first basic image to the (x+2), i.e., the second basic image is y/n times, that is, an intermediate image obtained as an image corresponding to 1/3 times the motion. First
When the interpolation image of 1 is the same as the basic image, the (x+1)th, that is, the first basic image can be used.

With the procedure up to this point, the display timing of the first interpolation image and the image to be displayed as the first interpolation image could be determined. Next, in procedure 4, the target interpolation image is moved from the first interpolation image to the second interpolation image. That is, k is changed from 1 to 2, and the procedure returns to step 1.

When k=2, in procedure 1, the display timing of the second interpolation image with respect to the first basic image is determined. The display timing of the second interpolation image is the time when a period in which the cycle of the input image data is multiplied by k(m/n), that is, 2/3, has elapsed since the first basic image was displayed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the second interpolation image is an integer. Here, the coefficient k(m/n) is 2/3 and is not an integer. Therefore, the procedure proceeds to step 3.

In procedure 3, the image used as the second interpolation image is determined. Therefore, the coefficient 2/3 is x
Convert to +y/n form. In the case of the coefficient 2/3, x=0 and y=2. When the second interpolation image is an intermediate image obtained by motion compensation, the second interpolation image is the (x+
1) That is, the motion of the image from the first basic image to the (x+2), that is, the second basic image is y/n times, that is, an intermediate image obtained as an image corresponding to 2/3 times the motion. Second
When the interpolation image of 1 is the same as the basic image, the (x+1)th, that is, the first basic image can be used.

By the procedure up to this point, the display timing of the second interpolation image and the image to be displayed as the second interpolation image could be determined. Next, in procedure 4, the target interpolation image is moved from the second interpolation image to the third interpolation image. That is, k is changed from 2 to 3, and the procedure returns to step 1.

When k=3, in Procedure 1, the display timing of the third interpolation image with respect to the first basic image is determined. The display timing of the third interpolation image is the time when a period in which the cycle of the input image data is multiplied by k (m/n), that is, one time has elapsed since the display of the first basic image.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the third interpolation image is an integer. Here, since the coefficient k(m/n) is 1, it is an integer. Therefore, at the display timing of the third interpolation image, the (k(m/n)+1)th, that is, the second basic image is displayed, and the first step is ended.

That is, when the conversion ratio is 3 (n/m=3),
The kth image is the basic image,
The k+1st image is an interpolated image,
The k+2th image is an interpolated image,
The k+3th image is a basic image, and the image display cycle is 1/3 times the cycle of the input image data.

As a concrete expression, when the conversion ratio is 3 (n/m=3),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
A method for driving a display device, which sequentially displays a k+3th image and an input image data cycle at an interval of ⅓ times,
The k-th image is displayed according to the i-th image data,
The k+1st image is displayed according to image data corresponding to a motion that is 1/3 times the motion from the i-th image data to the i+1-th image data,
The k+2nd image is displayed according to image data corresponding to a motion that is 2/3 times the motion from the i-th image to the i+1-th image,
The (k+3)th image is displayed according to the (i+1)th image data.

As another specific expression, when the conversion ratio is 3 (n/m=3),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
A method for driving a display device, which sequentially displays a k+3th image and an input image data cycle at an interval of ⅓ times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i-th image data,
The (k+3)th image is displayed according to the (i+1)th image data.

Here, when the conversion ratio is 3, there is an advantage that the quality of the moving image can be improved more than when the conversion ratio is smaller than 3. Further, when the conversion ratio is 3, there is an advantage that the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 3.

Specifically, when the conversion ratio is 3, it is also called triple speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 180 Hz (180 Hz drive). Then, the image is displayed three times in succession for one input image. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, AC drive of liquid crystal display device and 180Hz
It is also effective to combine driving. That is, the driving frequency of the liquid crystal display device is 180H.
z and the frequency of the AC drive is an integer multiple or an integer fraction thereof (for example, 45 Hz, 9
0 Hz, 180 Hz, 360 Hz, etc.), it is possible to reduce the flicker that appears due to alternating current drive to the extent that it cannot be perceived by the human eye.

n=3, m=2, that is, the conversion ratio (n/m) is 3/2 (where n=3, m=2 in FIG. 70)
In the case of, the operation in the first step is as follows. First, when k=1, step 1
Then, the display timing of the first interpolation image for the first basic image is determined. The display timing of the first interpolation image is the cycle of the input image data after the first basic image is displayed.
This is the time when a period of (m/n) times or 2/3 times has elapsed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the first interpolation image is an integer. Here, the coefficient k(m/n) is 2/3 and is not an integer. Therefore, the procedure proceeds to step 3.

In procedure 3, the image used as the first interpolation image is determined. Therefore, the coefficient 2/3 is x
Convert to +y/n form. In the case of the coefficient 2/3, x=0 and y=2. When the first interpolation image is an intermediate image obtained by motion compensation, the first interpolation image is the (x+
1) That is, the motion of the image from the first basic image to the (x+2), that is, the second basic image is y/n times, that is, an intermediate image obtained as an image corresponding to 2/3 times the motion. First
When the interpolation image of 1 is the same as the basic image, the (x+1)th, that is, the first basic image can be used.

With the procedure up to this point, the display timing of the first interpolation image and the image to be displayed as the first interpolation image could be determined. Next, in procedure 4, the target interpolation image is moved from the first interpolation image to the second interpolation image. That is, k is changed from 1 to 2, and the procedure returns to step 1.

When k=2, in procedure 1, the display timing of the second interpolation image with respect to the first basic image is determined. The display timing of the second interpolation image is the time when a period in which the cycle of the input image data is multiplied by k(m/n), that is, 4/3, has elapsed since the first basic image was displayed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the second interpolation image is an integer. Here, the coefficient k(m/n) is 4/3 and is not an integer. Therefore, the procedure proceeds to step 3.

In procedure 3, the image used as the second interpolation image is determined. Therefore, the coefficient 4/3 is x
Convert to +y/n form. In the case of the coefficient 4/3, x=1 and y=1. When the second interpolation image is an intermediate image obtained by motion compensation, the second interpolation image is the (x+
1) That is, the motion of the image from the second basic image to the (x+2), that is, the third basic image is an intermediate image obtained as an image corresponding to a motion of y/n times, that is, 1/3 times. Second
When the interpolated image of 1 is the same as the basic image, the (x+1)th, that is, the second basic image can be used.

By the procedure up to this point, the display timing of the second interpolation image and the image to be displayed as the second interpolation image could be determined. Next, in procedure 4, the target interpolation image is moved from the second interpolation image to the third interpolation image. That is, k is changed from 2 to 3, and the procedure returns to step 1.

When k=3, in Procedure 1, the display timing of the third interpolation image with respect to the first basic image is determined. The display timing of the third interpolation image is the time when a period in which the cycle of the input image data is multiplied by k (m/n), that is, doubled after the first basic image is displayed.

Next, in procedure 2, it is determined whether or not the coefficient k(m/n) used to determine the display timing of the third interpolation image is an integer. Here, since the coefficient k(m/n) is 2, it is an integer. Therefore, at the display timing of the third interpolation image, the (k(m/n)+1)th, that is, the third basic image is displayed, and the first step is ended.

That is, when the conversion ratio is 3/2 (n/m=3/2),
The kth image is the basic image,
The k+1st image is an interpolated image,
The k+2th image is an interpolated image,
The k+th image is a basic image, and the image display cycle is 2/3 times the cycle of the input image data.

As a concrete expression, when the conversion ratio is 3/2 (n/m=3/2),
The i-th (i is a positive integer) image data,
I+1th image data,
The i+2nd image data and the input image data are sequentially input at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
A driving method of a display device for sequentially displaying a k+3th image and an input image data cycle at an interval of ⅔ times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to image data corresponding to a motion that is 2/3 times the motion from the i-th image data to the i+1-th image data,
The k+2nd image has a motion of 1/3 of the motion from the i+1th image to the i+2th image.
It is displayed according to the image data corresponding to the doubled movement,
The k+th image is displayed according to the i+2 image data.

As another specific expression, when the conversion ratio is 3/2 (n/m=3/2),
The i-th (i is a positive integer) image data,
I+1th image data,
The i+2nd image data and the input image data are sequentially input at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
A driving method of a display device for sequentially displaying a k+3th image and an input image data cycle at an interval of ⅔ times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i+1th image data,
The k+th image is displayed according to the i+2 image data.

Here, when the conversion ratio is 3/2, there is an advantage that the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 3/2. Furthermore, when the conversion ratio is 3/2, the conversion ratio is 3/
It has an advantage that the power consumption and the manufacturing cost can be reduced as compared with the case of more than 2.

Specifically, when the conversion ratio is 3/2, it is also called 3/2 speed driving or 1.5 speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 90
Hz (90 Hz drive). Then, for the two input images, the images are displayed three times in succession. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. In particular, compared with a driving method with a large driving frequency such as 120 Hz driving (double speed driving) or 180 Hz driving (3 times speed driving), the operating frequency of the circuit that obtains the intermediate image can be reduced by motion compensation, so an inexpensive circuit can be used. The manufacturing cost and power consumption can be reduced. Furthermore, when the display device is an active matrix liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so
A particularly remarkable image quality improving effect is brought about with respect to obstacles such as afterimages. Furthermore, it is also effective to combine AC driving and 90 Hz driving of the liquid crystal display device. That is, while the drive frequency of the liquid crystal display device is set to 90 Hz, the frequency of AC drive is an integral multiple or an integer fraction (for example, 3).
0 Hz, 45 Hz, 90 Hz, 180 Hz, etc.) makes it possible to reduce the flicker that appears due to AC driving so that it is not perceived by the human eye.

The details of the procedure for positive integers n and m other than the above are omitted, but the conversion ratio can be set as an arbitrary rational number (n/m) by following the procedure of the frame rate conversion in the first step. it can. Among the combinations of positive integers n and m, the conversion ratio (n/
Combinations that can reduce m) can be handled in the same manner as conversion ratios after reduction.

For example, when n=4 and m=1, that is, when the conversion ratio (n/m) is 4 (where n=4 and m=1 in FIG. 70),
The kth image is the basic image,
The k+1st image is an interpolated image,
The k+2th image is an interpolated image,
The k+th image is an interpolated image,
The k+4th image is a basic image, and the image display cycle is 1/4 times the cycle of the input image data.

More specifically, when the conversion ratio is 4 (n/m=4),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
A driving method of a display device, which sequentially displays a k+4th image and an input image data at intervals of ¼ times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to image data corresponding to a motion that is 1/4 times the motion from the i-th image data to the i+1-th image data,
The k+2nd image is displayed according to image data corresponding to a movement obtained by halving the movement from the i-th image data to the i+1-th image data,
The k+th image is displayed according to image data corresponding to a motion that is 3/4 times the motion from the i-th image data to the i+1-th image data,
The k+4th image is displayed according to the i+1th image data.

As another specific expression, when the conversion ratio is 4 (n/m=4),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
A driving method of a display device, which sequentially displays a k+4th image and an input image data at intervals of ¼ times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i-th image data,
The k+th image is displayed according to the i-th image data,
The k+4th image is displayed according to the i+1th image data.

Here, when the conversion ratio is 4, there is an advantage that the quality of the moving image can be improved more than when the conversion ratio is smaller than 4. Further, when the conversion ratio is 4, there is an advantage that the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 4.

Specifically, when the conversion ratio is 4, it is also called quadruple speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 240 Hz (240 Hz drive). Then, the image is displayed four times in succession for one input image. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. In particular, 120
Compared with a driving method with a small driving frequency such as Hz driving (double speed driving) or 180 Hz driving (3 times speed driving), an intermediate image obtained by motion compensation with higher accuracy can be used as an interpolated image. The movement can be smoothed, and the quality of the moving image can be significantly improved. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Further, it is also effective to combine the AC drive and the 240 Hz drive of the liquid crystal display device. That is, by setting the drive frequency of the liquid crystal display device to 240 Hz, and setting the frequency of AC drive to an integral multiple or a fraction thereof (for example, 30 Hz, 40 Hz, 60 Hz, 120 Hz, etc.), flicker that appears due to AC drive is reduced. It can be reduced to a level not perceived by the human eye.

Furthermore, for example, n=4, m=3, that is, the conversion ratio (n/m) is 4/3 (n=n in FIG. 70).
4, m=3),
The kth image is the basic image,
The k+1st image is an interpolated image,
The k+2th image is an interpolated image,
The k+th image is an interpolated image,
The k+4th image is a basic image, and the image display cycle is 3/4 times the cycle of the input image data.

More specifically, when the conversion ratio is 4/3 (n/m=4/3),
The i-th (i is a positive integer) image data,
I+1th image data,
I+2nd image data,
The i+3rd image data and the input image data are sequentially input at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
A method of driving a display device, which sequentially displays the k+4th image and an input image data at intervals of 3/4 times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to image data corresponding to a motion that is 3/4 times the motion from the i-th image data to the i+1-th image data,
The k+th image has 1/2 of the movement from the i+1th image to the i+2th image.
It is displayed according to the image data corresponding to the doubled movement,
The k+th image is a quarter of the motion from the i+2th image to the i+3th image.
It is displayed according to the image data corresponding to the doubled movement,
The k+4th image is displayed according to the i+3rd image data.

As another specific expression, when the conversion ratio is 4/3 (n/m=4/3),
The i-th (i is a positive integer) image data,
I+1th image data,
I+2nd image data,
The i+3rd image data and the input image data are sequentially input at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
A method of driving a display device, which sequentially displays the k+4th image and an input image data at intervals of 3/4 times,
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i+1th image data,
The k+th image is displayed according to the i+2 image data,
The k+4th image is displayed according to the i+3rd image data.

Here, when the conversion ratio is 4/3, there is an advantage that the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 4/3. Furthermore, when the conversion ratio is 4/3, the conversion ratio is 4/
It has an advantage that the power consumption and the manufacturing cost can be reduced as compared with the case of more than 3.

Specifically, when the conversion ratio is 4/3, it is also referred to as 4/3 speed driving or 1.25 speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 8
It is 0 Hz (80 Hz drive). Then, the image is displayed four times in succession for the three input images. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. In particular, compared with a driving method with a large driving frequency such as 120 Hz driving (double speed driving) or 180 Hz driving (3 times speed driving), the operating frequency of the circuit that obtains the intermediate image can be reduced by motion compensation, so an inexpensive circuit can be used. The manufacturing cost and power consumption can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Further, it is also effective to combine the AC drive and the 80 Hz drive of the liquid crystal display device. That is, while the drive frequency of the liquid crystal display device is set to 80 Hz, the frequency of AC drive is set to an integral multiple or an integral fraction thereof (for example,
40 Hz, 80 Hz, 160 Hz, 240 Hz, etc.), it is possible to reduce flicker that appears due to alternating current drive to a level that is not perceived by human eyes.

Furthermore, for example, n=5, m=1, that is, the conversion ratio (n/m) is 5 (n=5 in FIG. 70,
If m=1),
The kth image is the basic image,
The k+1st image is an interpolated image,
The k+2th image is an interpolated image,
The k+th image is an interpolated image,
The k+4th image is an interpolated image,
The k+5th image is a basic image, and the image display cycle is ⅕ times the cycle of the input image data.

More specifically, when the conversion ratio is 5 (n/m=5),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
The k+4th image,
A driving method of a display device for sequentially displaying a k+5th image and an input image data at intervals of ⅕ times the cycle of
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to image data corresponding to a movement that is ⅕ times the movement from the i-th image data to the i+1-th image data,
The k+2nd image is displayed according to image data corresponding to a movement that is 2/5 times the movement from the i-th image data to the i+1-th image data,
The k+th image is displayed according to image data corresponding to a motion that is 3/5 times the motion from the i-th image data to the i+1-th image data,
The k+4th image is displayed according to image data corresponding to a motion that is 4/5 times the motion from the i-th image data to the i+1-th image data,
The k+5th image is displayed according to the i+1th image data.

As another more specific expression, when the conversion ratio is 5 (n/m=5),
The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially input as input image data at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
The k+4th image,
A driving method of a display device for sequentially displaying a k+5th image and an input image data at intervals of ⅕ times the cycle of
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i-th image data,
The k+th image is displayed according to the i-th image data,
The k+4th image is displayed according to the i-th image data,
The k+5th image is displayed according to the i+1th image data.

Here, when the conversion ratio is 5, there is an advantage that the quality of the moving image can be improved more than when the conversion ratio is smaller than 5. Further, when the conversion ratio is 5, there is an advantage that the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 5.

Specifically, when the conversion ratio is 5, it is also called 5× speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 300 Hz (300 Hz drive). Then, for one input image, the image is displayed five times in succession. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. In particular, 120
Compared with a driving method with a small driving frequency such as Hz driving (double speed driving) or 180 Hz driving (3 times speed driving), an intermediate image obtained by motion compensation with higher accuracy can be used as an interpolated image. The movement can be smoothed, and the quality of the moving image can be significantly improved. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Further, it is also effective to combine AC driving and 300 Hz driving of the liquid crystal display device. That is, while the driving frequency of the liquid crystal display device is set to 300 Hz, the frequency of AC driving is set to an integral multiple or a fraction (for example, 30 Hz, 50 Hz, 60 Hz, 100 Hz, etc.) of flicker that appears due to AC driving. It can be reduced to a level that is not perceived by the human eye.

Further, for example, n=5, m=2, that is, the conversion ratio (n/m) is 5/2 (n=in FIG. 70).
5, where m=2),
The kth image is the basic image,
The k+1st image is an interpolated image,
The k+2th image is an interpolated image,
The k+th image is an interpolated image,
The k+4th image is an interpolated image,
The k+5th image is a basic image, and the image display cycle is ⅕ times the cycle of the input image data.

More specifically, when the conversion ratio is 5/2 (n/m=5/2),
The i-th (i is a positive integer) image data,
I+1th image data,
The i+2nd image data and the input image data are sequentially input at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
The k+4th image,
A driving method of a display device for sequentially displaying a k+5th image and an input image data at intervals of ⅕ times the cycle of
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to image data corresponding to a movement that is 2/5 times the movement from the i-th image data to the i+1-th image data,
The k+2nd image is displayed according to image data corresponding to a movement that is 4/5 times the movement from the i-th image data to the i+1-th image data.
The k+th image is displayed according to image data corresponding to a movement that is ⅕ times the movement from the i+1-th image data to the i+2-th image data.
The k+4th image is displayed in accordance with image data corresponding to a movement that is 3/5 times the movement from the i+1th image data to the i+2th image data.
The k+5th image is displayed according to the i+2nd image data.

As another specific expression, when the conversion ratio is 5/2 (n/m=5/2),
The i-th (i is a positive integer) image data,
I+1th image data,
The i+2nd image data and the input image data are sequentially input at a constant cycle,
The k-th (k is a positive integer) image,
The (k+1)th image,
The k+2nd image,
The k+3th image,
The k+4th image,
A driving method of a display device for sequentially displaying a k+5th image and an input image data at intervals of ⅕ times the cycle of
The k-th image is displayed according to the i-th image data,
The (k+1)th image is displayed according to the i-th image data,
The k+2nd image is displayed according to the i-th image data,
The k+th image is displayed according to the i+1-th image data,
The k+4th image is displayed according to the i+1th image data,
The k+5th image is displayed according to the i+2nd image data.

Here, when the conversion ratio is 5/2, there is an advantage that the quality of the moving image can be improved more than when the conversion ratio is smaller than 5/2. Further, when the conversion ratio is 5/2, there is an advantage that the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 5.

Specifically, when the conversion ratio is 5, it is also called 5/2 speed driving or 2.5 speed driving. For example, if the input frame rate is 60Hz, the display frame rate is 150H.
z (150 Hz drive). Then, for the two input images, the images are displayed five times in succession. At this time, when the interpolated image is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, and thus the quality of the moving image can be significantly improved. In particular, as compared with a driving method with a small driving frequency such as 120 Hz driving (double speed driving), an intermediate image obtained by motion compensation with higher accuracy can be used as an interpolation image, so that the motion of a moving image is smoothed further. It is possible to significantly improve the quality of moving images. Further, as compared with a driving method with a large driving frequency such as 180 Hz driving (3× speed driving), the operating frequency of the circuit for obtaining the intermediate image by motion compensation can be reduced, so that an inexpensive circuit can be used, and the manufacturing cost and power consumption can be reduced. It can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, it is also effective to combine AC driving and 150 Hz driving of the liquid crystal display device. That is, the driving frequency of the liquid crystal display device is 150 Hz.
However, the frequency of the AC drive is an integral multiple or a fraction thereof (for example, 30 Hz, 50
Hz, 75 Hz, 150 Hz, etc.), it is possible to reduce the flicker that appears due to AC driving so that it cannot be perceived by human eyes.

By thus setting the positive integers n and m variously, the conversion ratio can be set as an arbitrary rational number (n/m). Although detailed description is omitted, when n is 10 or less,
n=1, m=1, that is, conversion ratio (n/m)=1 (1× speed drive, 60 Hz),
n=2, m=1, that is, conversion ratio (n/m)=2 (double speed drive, 120 Hz),
n=3, m=1, that is, conversion ratio (n/m)=3 (3× speed drive, 180 Hz),
n=3, m=2, that is, conversion ratio (n/m)=3/2 (3/2 speed drive, 90 Hz),
n=4, m=1, that is, conversion ratio (n/m)=4 (4× speed drive, 240 Hz),
n=4, m=3, that is, conversion ratio (n/m)=4/3 (4/3 double speed drive, 80 Hz),
n=5, m=1, that is, conversion ratio (n/m)=5/1 (5× speed drive, 300 Hz),
n=5, m=2, that is, conversion ratio (n/m)=5/2 (5/2 speed drive, 150 Hz),
n=5, m=3, that is, conversion ratio (n/m)=5/3 (5/3 speed drive, 100 Hz),
n=5, m=4, that is, conversion ratio (n/m)=5/4 (5/4 speed drive, 75 Hz),
n=6, m=1, that is, conversion ratio (n/m)=6 (6× speed drive, 360 Hz),
n=6, m=5, that is, conversion ratio (n/m)=6/5 (6/5 speed drive, 72 Hz),
n=7, m=1, that is, conversion ratio (n/m)=7 (7× speed drive, 420 Hz),
n=7, m=2, that is, conversion ratio (n/m)=7/2 (7/2 speed drive, 210 Hz),
n=7, m=3, that is, conversion ratio (n/m)=7/3 (7/3 double speed drive, 140 Hz),
n=7, m=4, that is, conversion ratio (n/m)=7/4 (7/4 speed drive, 105 Hz),
n=7, m=5, that is, conversion ratio (n/m)=7/5 (7/5 double speed drive, 84 Hz),
n=7, m=6, that is, conversion ratio (n/m)=7/6 (7/6 double speed drive, 70 Hz),
n=8, m=1, that is, conversion ratio (n/m)=8 (8× speed drive, 480 Hz),
n=8, m=3, that is, conversion ratio (n/m)=8/3 (8/3 speed drive, 160 Hz),
n=8, m=5, that is, conversion ratio (n/m)=8/5 (8/5 double speed drive, 96 Hz),
n=8, m=7, that is, conversion ratio (n/m)=8/7 (8/7 double speed drive, 68.6 Hz)
,
n=9, m=1, that is, conversion ratio (n/m)=9 (9×speed drive, 540 Hz),
n=9, m=2, that is, conversion ratio (n/m)=9/2 (9/2 double speed drive, 270 Hz),
n=9, m=4, that is, conversion ratio (n/m)=9/4 (9/4 speed drive, 135 Hz),
n=9, m=5, that is, conversion ratio (n/m)=9/5 (9/5 speed drive, 108 Hz),
n=9, m=7, that is, conversion ratio (n/m)=9/7 (9/7 double speed drive, 77.1 Hz)
,
n=9, m=8, that is, conversion ratio (n/m)=9/8 (9/8 speed drive, 67.5 Hz)
,
n=10, m=1, that is, conversion ratio (n/m)=10 (10× speed drive, 600 Hz),
n=10, m=3, that is, conversion ratio (n/m)=10/3 (10/3 speed drive, 200H)
z),
n=10, m=7, that is, conversion ratio (n/m)=10/7 (10/7 double speed drive, 85.7)
Hz),
n=10, m=9, that is, conversion ratio (n/m)=10/9 (10/9 speed drive, 66.7)
Hz),
Combinations of the above are possible. Note that the notation of frequency is an example when the input frame rate is 60 Hz, and for other input frame rates, the value obtained by integrating each conversion ratio with the input frame rate becomes the drive frequency.

In addition, when n is an integer greater than 10, specific numbers of n and m are not given, but the procedure of the frame rate conversion in the first step can be applied to various n and m. Is clear.

It should be noted that the conversion ratio can be determined depending on how many of the displayed images the input image data can display without motion compensation. Specifically, the smaller m is, the larger the ratio of images that can be displayed in the input image data without performing motion compensation. If the frequency of motion compensation is low, the frequency of operation of the circuit that performs motion compensation can be reduced, so power consumption can be reduced, and an image that includes an error due to motion compensation (correctly reflects the motion of the image. Since it is possible to reduce the possibility that an intermediate image) that is not created will be created, the quality of the image can be improved. As such a conversion ratio, when n is 10 or less, for example, 1, 2, 3, 3/2, 4,
5,5/2,6,7,7/2,8,9,9/2,10. By using such a conversion ratio, it is possible to improve image quality and reduce power consumption, especially when an intermediate image obtained by motion compensation is used as an interpolation image. This is because when m is 2, the number of images that can be displayed in the input image data without performing motion compensation is relatively large (there is only 1/2 of the total number of input image data). ,
This is because the frequency of motion compensation is reduced. Further, when m is 1, the number of images that can be displayed in the input image data without performing motion compensation is large (equal to the total number of input image data), and motion compensation is not performed. is there. On the other hand, as m is larger, an intermediate image created by highly accurate motion compensation can be used, which has an advantage that the motion of the image can be made smoother.

When the display device is a liquid crystal display device, the conversion ratio can be determined according to the response time of the liquid crystal element. Here, the response time of the liquid crystal element is the time from when the voltage applied to the liquid crystal element is changed until the liquid crystal element responds. When the response time of the liquid crystal element varies depending on the amount of change in the voltage applied to the liquid crystal element, the average value of the response times for a plurality of typical voltage changes can be used. Alternatively, the response time of the liquid crystal element is MPRT (Movin
g Picture Response Time).
Then, by the frame rate conversion, the conversion ratio can be determined so that the image display cycle becomes close to the response time of the liquid crystal element. Specifically, the response time of the liquid crystal element is preferably the time from the value obtained by integrating the period of the input image data and the reciprocal of the conversion ratio to a value of about half this value. By doing so, the image display cycle can be set in accordance with the response time of the liquid crystal element, so that the image quality can be improved. For example, when the response time of the liquid crystal element is 4 milliseconds or more and 8 milliseconds or less, double speed driving (120 Hz driving) can be performed. This is because the image display cycle of 120 Hz drive is about 8 milliseconds, and half of the image display cycle of 120 Hz drive is about 4 milliseconds. Similarly, for example, when the response time of the liquid crystal element is 3 milliseconds or more and 6 milliseconds or less, triple speed drive (180 Hz drive) can be performed, and the response time of the liquid crystal element is 5
It can be driven at 1.5 times speed (90 Hz drive) in the case of millisecond or more and 11 milliseconds or less, and 4 times speed drive (240 Hz driving) when the response time of the liquid crystal element is 2 milliseconds or more and 4 milliseconds or less. ), and when the response time of the liquid crystal element is 6 milliseconds or more and 12 milliseconds or less, 1
． It can be driven at 25 times speed (80 Hz drive). The same applies to other drive frequencies.

The conversion ratio can also be determined by the trade-off between the quality of moving images and the power consumption and manufacturing cost. That is, the quality of moving images can be improved by increasing the conversion ratio, while the power consumption and the manufacturing cost can be reduced by decreasing the conversion ratio. That is, each conversion ratio in the range where n is 10 or less has the following advantages.

When the conversion ratio is 1, the quality of the moving image can be improved more than when the conversion ratio is smaller than 1, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 1. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about one time the cycle of the input image data.

When the conversion ratio is 2, the quality of the moving image can be improved more than when the conversion ratio is less than 2, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 2. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about half the cycle of the input image data.

When the conversion ratio is 3, the quality of the moving image can be improved more than when the conversion ratio is less than 3, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 3. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅓ times the cycle of the input image data.

When the conversion ratio is 3/2, the quality of the moving image can be improved more than when the conversion ratio is smaller than 3/2, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 3/2. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅔ of the cycle of the input image data.

When the conversion ratio is 4, the quality of the moving image can be improved more than when the conversion ratio is less than 4, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 4. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ¼ the cycle of the input image data.

When the conversion ratio is 4/3, the quality of the moving image can be improved more than when the conversion ratio is less than 4/3, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 4/3. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 3/4 times the cycle of the input image data.

When the conversion ratio is 5, the moving image quality can be improved more than when the conversion ratio is less than 5, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 5. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅕ times the cycle of input image data, the image quality can be improved.

When the conversion ratio is 5/2, the quality of the moving image can be improved more than when the conversion ratio is less than 5/2, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is more than 5/2. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 2/5 times the cycle of the input image data.

When the conversion ratio is 5/3, the quality of the moving image can be improved more than when the conversion ratio is smaller than 5/3, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 5/3. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying to a liquid crystal display device in which the response time of the liquid crystal element is about 3/5 times the cycle of the input image data.

When the conversion ratio is 5/4, the quality of the moving image can be improved more than when the conversion ratio is smaller than 5/4, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 5/4. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 4/5 times the cycle of the input image data.

When the conversion ratio is 6, the quality of the moving image can be improved more than when the conversion ratio is less than 6, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 6. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅙ times the cycle of the input image data.

When the conversion ratio is 6/5, the quality of the moving image can be improved more than when the conversion ratio is less than 6/5, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 6/5. Furthermore, since m is large, the movement of the image can be made smoother. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 5/6 times the cycle of the input image data, the image quality can be improved.

When the conversion ratio is 7, the quality of the moving image can be improved more than when the conversion ratio is less than 7, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 7. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 1/7 times the cycle of the input image data.

When the conversion ratio is 7/2, the quality of the moving image can be improved more than when the conversion ratio is less than 7/2, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 7/2. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 2/7 times the cycle of the input image data, the image quality can be improved.

When the conversion ratio is 7/3, the quality of the moving image can be improved more than when the conversion ratio is less than 7/3, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 7/3. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 3/7 times the cycle of the input image data.

When the conversion ratio is 7/4, the quality of the moving image can be improved more than when the conversion ratio is less than 7/4, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 7/4. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 4/7 times the cycle of the input image data.

When the conversion ratio is 7/5, the quality of the moving image can be improved more than when the conversion ratio is less than 7/5, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 7/5. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 5/7 times the cycle of the input image data.

When the conversion ratio is 7/6, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 7/6, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 7/6. Furthermore, since m is large, the movement of the image can be made smoother. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 6/7 times the cycle of the input image data, the image quality can be improved.

When the conversion ratio is 8, the quality of the moving image can be improved more than when the conversion ratio is less than 8, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 8. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅛ times the cycle of input image data, the image quality can be improved.

When the conversion ratio is 8/3, the quality of the moving image can be improved more than when the conversion ratio is less than 8/3, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 8/3. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅜ times the cycle of the input image data.

When the conversion ratio is 8/5, the quality of the moving image can be improved more than when the conversion ratio is less than 8/5, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 8/5. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 5/8 times the cycle of the input image data.

When the conversion ratio is 8/7, the quality of the moving image can be improved more than when the conversion ratio is smaller than 8/7, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 8/7. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 7/8 times the cycle of the input image data.

When the conversion ratio is 9, the quality of the moving image can be improved more than when the conversion ratio is smaller than 9, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 9. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 1/9 times the cycle of the input image data.

When the conversion ratio is 9/2, the quality of the moving image can be improved more than when the conversion ratio is smaller than 9/2, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 9/2. Furthermore, since m is small, high image quality can be obtained while power consumption can be reduced. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 2/9 times the cycle of the input image data.

When the conversion ratio is 9/4, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 9/4, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 9/4. Furthermore, since m is large, the movement of the image can be made smoother. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 4/9 times the cycle of input image data, the image quality can be improved.

When the conversion ratio is 9/5, the quality of the moving image can be improved more than when the conversion ratio is less than 9/5, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 9/5. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 5/9 times the cycle of the input image data.

When the conversion ratio is 9/7, the quality of the moving image can be improved more than when the conversion ratio is less than 9/7, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 9/7. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 7/9 times the cycle of the input image data.

When the conversion ratio is 9/8, the quality of the moving image can be improved more than when the conversion ratio is less than 9/8, and the power consumption and the manufacturing cost can be reduced than when the conversion ratio is greater than 9/8. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 8/9 times the cycle of the input image data.

When the conversion ratio is 10, the quality of the moving image can be improved more than when the conversion ratio is smaller than 10.
The power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 10. Furthermore, m
Is small, power consumption can be reduced while high image quality can be obtained. Further, by applying to a liquid crystal display device in which the response time of the liquid crystal element is about 1/10 of the cycle of input image data,
The image quality can be improved.

When the conversion ratio is 10/3, the quality of the moving image can be improved more than when the conversion ratio is less than 10/3, and the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is greater than 10/3. Furthermore, since m is large, the movement of the image can be made smoother. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 3/10 times the cycle of the input image data, the image quality can be improved.

When the conversion ratio is 10/7, the quality of the moving image can be improved more than when the conversion ratio is smaller than 10/7, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 10/7. Furthermore, since m is large, the movement of the image can be made smoother. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 7/10 times the cycle of the input image data.

When the conversion ratio is 10/9, the quality of the moving image can be improved more than when the conversion ratio is smaller than 10/9, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 10/9. Furthermore, since m is large, the movement of the image can be made smoother. Further, by applying to a liquid crystal display device in which the response time of the liquid crystal element is about 9/10 times the cycle of the input image data, the image quality can be improved.

It is apparent that each conversion ratio in the range where n is larger than 10 has the same advantage.

Next, as a second step, an image according to the input image data or each image subjected to frame rate conversion to any rational number (n/m) times in the first step (hereinafter referred to as an original image) ), a plurality of different images (sub-images) are created, and the plurality of sub-images are sequentially presented in time. By doing so, even though a plurality of images are actually presented, it is possible for the human eye to perceive it as if one original image was displayed.

Here, of the sub-images created from one original image, the sub-image displayed first is referred to as a first sub-image. Here, it is assumed that the timing of displaying the first sub-image is the same as the timing of displaying the original image determined in the first step. on the other hand,
The sub-image displayed after that will be called the second sub-image. The timing of displaying the second sub-image can be arbitrarily determined regardless of the timing of displaying the original image determined in the first step. The image to be actually displayed is an image created from the original image by the method in the second step. Various images can be used as the original image for creating the sub image. The number of sub-images is not limited to two and may be larger than two. In the second step, the number of sub-images is described as J (J is an integer of 2 or more). At this time, the sub-image displayed at the same timing as the timing of displaying the original image determined in the first step is called the first sub-image, and the sub-images subsequently displayed thereafter are displayed. The second sub-image, the third sub-image,...
, J th sub-image.

There are various methods for creating a plurality of sub-images from one original image, and the following are the main ones. One is a method of using the original image as it is as a sub-image. One is a method of distributing the brightness of the original image to a plurality of sub-images. One is a method of using an intermediate image obtained by motion compensation as a sub-image.

Here, the method of distributing the brightness of the original image to the plurality of sub-images can be further divided into a plurality of methods. The main methods are as follows. One is a method in which at least one sub-image is a black image (referred to as a black insertion method). One is
When the brightness of the original image is divided into a plurality of ranges and the brightness in the range is controlled, a method is performed by using only one sub-image among all the sub-images (referred to as a time division gradation control method). ). One is a method in which one sub-image is a bright image in which the gamma value of the original image is changed, and the other sub-image is a dark image in which the gamma value of the original image is changed (called a gamma complement method). ).

Each of the above methods is briefly described. The method of using the original image as it is as the sub image uses the original image as it is as the first sub image. Further, the original image is used as it is as the second sub-image. By using this method, it is possible to reduce power consumption and manufacturing cost because a circuit for newly creating a sub-image is not operated or it is not necessary to use the circuit itself. Particularly in the liquid crystal display device, the first
In this step, it is preferable to use this method after performing frame rate conversion using the intermediate image obtained by motion compensation as an interpolated image. This is because by using an intermediate image obtained by motion compensation as an interpolated image, the motion of the moving image is smoothed and the same image is repeatedly displayed, resulting in insufficient writing voltage due to the dynamic voltage of the liquid crystal element. This is because obstacles such as tailing and afterimage can be reduced.

Next, in the method of distributing the brightness of the original image to the plurality of sub-images, a method of setting the brightness of the image and the length of the period during which the sub-image is displayed will be described in detail. Note that J represents the number of sub-images and is an integer of 2 or more. Lowercase j is distinguished from uppercase J. It is assumed that j is an integer of 1 or more and J or less.
The brightness of the pixel in the normal hold driving is L, the cycle of the original image data is T,
The brightness L _j of the pixels in the sub-image of the _j, the length T _j of the period in which the sub image is displayed in the first _j, and when taking a product for L _j and T _j, from which the j = 1 The sum up to j=J (L
It is preferable that ₁ T ₁ +L ₂ T ₂ +... +L _J T _J ) is equal to the product of L and T (LT) (the brightness is unchanged). Furthermore, the total sum (T ₁ +T ₂ +...+T _J ) of T _j from j=1 to j=J is equal to T (the display cycle of the original image is maintained). preferable. Here, the fact that the brightness is unchanged and the display cycle of the original image is maintained is referred to as a sub-image distribution condition.

Among the methods of distributing the brightness of the original image to the plurality of sub-images, the black insertion method is a method of making at least one sub-image a black image. By doing so, since the display method can be pseudo impulse type, it is possible to prevent the quality of the moving image from being degraded due to the hold type display method. Here, in order to prevent a decrease in the brightness of the display image due to the insertion of the black image, it is preferable to comply with the sub-image distribution condition. However, if the situation is such that the decrease in the brightness of the display image is acceptable (the surroundings are dark, etc.), or if the user has set the decrease in the brightness of the display image to be acceptable, the sub-image The distribution conditions may not be obeyed. For example, one sub-image may be the same as the original image and the other sub-images may be black images. In this case, power consumption can be reduced compared to when the sub-image distribution condition is followed. Further, in the liquid crystal display device, when one of the sub-images is the one in which the overall brightness of the original image is increased without limiting the maximum brightness value, the brightness of the backlight is increased. Then, the sub-image distribution condition may be realized. In this case, the sub-image distribution condition can be satisfied without controlling the voltage value to be written in the pixel, so that the operation of the image processing circuit can be omitted and the power consumption can be reduced.

The black insertion method is characterized by setting L _{j of} all pixels to 0 in any one sub-image. By doing so, since the display method can be pseudo impulse type, it is possible to prevent the quality of moving images from being deteriorated due to the hold type display method.

Among the methods of distributing the brightness of the original image to the plurality of sub-images, the time division gradation control method divides the brightness of the original image into a plurality of ranges, and when controlling the brightness in the range, all This is a method of using only one sub-image among the sub-images. By doing so, the display method can be set to the pseudo impulse type without lowering the brightness, so that it is possible to prevent the deterioration of the moving image quality due to the hold type display method.

As a method of dividing the brightness of the original image into a plurality of ranges, the maximum brightness value (L _max ) is
There is a method of dividing by the number of sub-images. This is because, for example, in a display device in which the brightness from 0 to L _max can be adjusted in 256 steps (gradation 0 to gradation 255), when the number of sub-images is 2, gradation 0 to gradation 127 When displaying, the brightness of one sub-image is adjusted in the range of gradation 0 to gradation 255, while the brightness of the other sub-image is set to gradation 0,
When displaying gradations from 128 to 255, the brightness of one of the sub-images is set to 255.
On the other hand, the brightness of the other sub-image is adjusted in the range of gradation 0 to gradation 255. By doing so, it can be perceived by the human eye as if the original image was displayed, and it can be pseudo impulse type, so that the quality of the moving image is reduced due to the hold type. Can be prevented. The number of sub-images may be larger than two. For example, when the number of sub-images is 3, the brightness level of the original image (from gradation 0 to gradation 2
55) is divided into three. Depending on the number of brightness levels of the original image and the number of sub-images, the number of brightness levels may not be divisible by the number of sub-images, but is included in each brightness range after division. The number of brightness levels does not have to be the same, but may be appropriately distributed.

Note that the time-division gradation control method is also preferable because it is possible to display an image similar to the original image without lowering the brightness by satisfying the sub-image distribution condition.

Among the methods of distributing the brightness of the original image to multiple sub-images, the gamma complement method is one of the sub-images is a bright image with the gamma characteristics of the original image changed, and the other sub-image is the gamma of the original image. This is a method of making a dark image with changed characteristics. By doing so, the display method can be set to the pseudo impulse type without lowering the brightness, so that it is possible to prevent the deterioration of the moving image quality due to the hold type display method. Here, the gamma characteristic is the degree of brightness with respect to the brightness level (gradation). Normally, the gamma characteristic is adjusted to be close to linear. This is because a smooth gradation can be obtained by making the change in the brightness proportional to the gradation, which is the brightness level. In the gamma complement method, the gamma characteristic of one of the sub-images is shifted from the linear one, and is adjusted so that it becomes brighter than the linear one in the region of intermediate brightness (halftone) (the image becomes brighter than it should be). )
.. Then, the gamma characteristic of the other sub-image is also shifted from linear, and adjustment is performed so that it is darker than linear in the same halftone region (halftone becomes an image darker than it should be). Here, the amount by which one sub-image is brighter than linear and the amount by which the other sub-image is darker than linear is
It is preferable to make them approximately equal in all gradations. By doing so, the original image can be perceived by the human eye as if it was displayed, and it is possible to prevent the quality of the moving image from deteriorating due to the hold type. The number of sub-images may be larger than two. For example, when the number of sub-images is 3, the gamma characteristic is adjusted for each of the three sub-images so that the total amount of lightening from linear to the total amount of darkening from linear is approximately equal. Good.

Note that the gamma complement method is also preferable because it is possible to display an image similar to the original image without causing a decrease in brightness by satisfying the sub image distribution condition. further,
In the gamma complement method, since the change in the brightness L _j of each sub-image with respect to the gradation follows the gamma curve, each sub-image can display the gradation by itself,
Finally, it has the advantage that the quality of the image perceived by the human eye is also improved.

A method of using an intermediate image obtained by motion compensation as a sub-image is a method of making one of the sub-images an intermediate image obtained by motion compensation from the preceding and following images. By doing so, the movement of the image can be smoothed, and the quality of the moving image can be improved.

Next, the relationship between the timing of displaying the sub-image and the method of creating the sub-image will be described. The timing for displaying the first sub-image is the same as the timing for displaying the original image determined in the first step, and the timing for displaying the second sub-image is the same as the timing determined for the original image determined in the first step. Although it can be arbitrarily determined regardless of the timing of displaying the image, the sub image itself may be changed according to the timing of displaying the second sub image. By doing so, even if the timing of displaying the second sub-image is variously changed, it can be perceived by human eyes as if the original image was displayed. Specifically, when the timing of displaying the second sub-image is advanced, the first sub-image is made brighter, and the second sub-image is made brighter.
The sub-images of can be darker. Furthermore, when the timing of displaying the second sub-image is delayed, the first sub-image can be made darker and the second sub-image can be made brighter. This is because the brightness perceived by the human eye changes depending on the length of the image display period. More specifically, the brightness perceived by human eyes becomes brighter as the image display period is longer, and darker as the image display period is shorter. That is, by shortening the display timing of the second sub-image, the length of the period for displaying the first sub-image is shortened, and the length of the period for displaying the second sub-image is lengthened. As it is, the first sub-image is dark and the second sub-image is bright, and is perceived by human eyes. As a result, an image different from the original image will be perceived by the human eye. To prevent this, the first
Sub-images can be brighter and the second sub-image can be darker. Similarly, the second
By delaying the timing of displaying the sub-image of, the length of the period for displaying the first sub-image becomes longer and the length of the period for displaying the second sub-image becomes shorter, The sub-image can be darker and the second sub-image can be lighter.

The processing procedure in the second step is shown below based on the above description.
As the procedure 1, a method of creating a plurality of sub-images from one original image is determined. More specifically, a method of creating a plurality of sub-images includes a method of directly using the original image as a sub-image, a method of distributing the brightness of the original image to the plurality of sub-images, and an intermediate image obtained by motion compensation as a sub-image. Can be selected from the methods used as.
As procedure 2, the number J of sub-images is determined. Note that J is an integer of 2 or more.
As procedure 3, the pixel brightness L _j in the j-th sub-image and the length T _{j of the} period in which the j-th sub-image is displayed are determined according to the method selected in the procedure 1. By the procedure 3, the length of the period in which each sub-image is displayed and the brightness of each pixel included in each sub-image are specifically determined.
As procedure 4, the original image is processed according to the items determined in each of procedure 1 to procedure 3 and is actually displayed.
In step 5, the target original image is moved to the next original image. Then, the procedure returns to step 1.

The mechanism for executing the procedure in the second step may be implemented in the device or may be predetermined in the design stage of the device. If a mechanism for executing the procedure in the second step is installed in the device, it becomes possible to switch the driving method so that the optimum operation according to the situation is performed. The conditions here include the contents of image data, the environment inside and outside the device (temperature, humidity, atmospheric pressure, light, sound, magnetic field, electric field, radiation dose,
Altitude, acceleration, moving speed, etc.), user settings, software version, etc. On the other hand, if the mechanism for executing the procedure in the second step is predetermined in the design stage of the device, the optimum driving circuit for each driving method can be used, and the mechanism is determined. As a result, it is possible to expect a reduction in manufacturing cost due to the effect of mass production.

Next, various driving methods determined by the procedure in the second step will be described in detail by specifically showing the values of n and m in the first step.

When the method of using the original image as it is as the sub image is selected in the procedure 1 in the second step, the driving method is as follows.

The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially prepared at a constant cycle T,
The cycle T is divided into J (J is an integer of 2 or more) sub-image display periods,
The i-th image data is data that allows each of a plurality of pixels to have a unique brightness L,
The j-th (j is an integer of 1 or more and J or less) sub-image is configured by arranging a plurality of pixels each having a unique brightness L _j, and is displayed for the j-th sub-image display period T _j. Image,
A driving method of a display device, wherein L, T, L _j , and T _j are sub-image distribution conditions,
In all j, the brightness L _j of each pixel included in the j-th sub-image is L _j =L for each pixel.
Here, the original image data created in the first step can be used as the image data that is sequentially prepared in the constant cycle T. That is, all the display patterns mentioned in the description of the first step can be combined with the above driving method.

When the number J of sub-images is determined to be 2 in the procedure 2 in the second step and T ₁ =T ₂ =T/2 is determined in the procedure 3, the driving method is shown in FIG. It will be something like.
In FIG. 71, the horizontal axis represents time, and the vertical axis represents various n and m used in the first step in different cases.

For example, in the first step, when n=1, m=1, that is, when the conversion ratio (n/m) is 1, a driving method as shown in n=1, m=1 in FIG. Become. At this time, the display frame rate is twice the frame rate of the input image data (double speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 120 Hz (120 Hz drive). Then, the image is displayed twice consecutively for one input image data. Here, in the case of the double speed drive, the quality of the moving image can be improved as compared with the case where the frame rate is lower than the double speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is higher than the double speed. Furthermore, in the procedure 1 of the second step,
By selecting the method of using the original image as a sub image as it is, the operation of the circuit that creates the intermediate image by motion compensation can be stopped or the circuit itself can be omitted from the device, resulting in power consumption and manufacturing cost of the device. Can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Further, it is also effective to combine the AC drive and the 120 Hz drive of the liquid crystal display device. That is, while the drive frequency of the liquid crystal display device is 120 Hz, the frequency of AC drive is an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz).
, 120 Hz, 240 Hz, etc.), it is possible to reduce the flicker that appears due to AC driving to the extent that it cannot be perceived by human eyes. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about half the cycle of the input image data.

Further, for example, in the first step, n=2, m=1, that is, the conversion ratio (n/m
) Is 2, the driving method is as shown at n=2 and m=1 in FIG. At this time, the display frame rate is four times the frame rate of the input image data (four-fold speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 240 Hz (240 Hz drive). Then, the image is displayed four times in succession for one input image data. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Here, in the case of the 4× speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is lower than the 4× speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is higher than the 4× speed. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device,
Since the problem of insufficient write voltage due to the dynamic capacitance can be avoided, a particularly remarkable image quality improving effect can be obtained against obstacles such as tailing of a moving image and afterimage. Further, it is also effective to combine the AC drive and the 240 Hz drive of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 240 Hz and setting the frequency of AC driving to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 240 Hz, etc.), flicker that appears due to AC driving, It can be reduced to a level that is not perceived by the human eye. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ¼ the cycle of the input image data.

Further, for example, in the first step, n=3, m=1, that is, the conversion ratio (n/m
)=3, the driving method is as shown at n=3 and m=1 in FIG. At this time, the display frame rate is 6 times the frame rate of the input image data (6× speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 360 Hz (360 Hz drive). Then, the image is displayed six times in succession for one input image data. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Here, in the case of the 6× speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is lower than the 6× speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is higher than the 6× speed. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device,
Since the problem of insufficient write voltage due to the dynamic capacitance can be avoided, a particularly remarkable image quality improving effect can be obtained against obstacles such as tailing of a moving image and afterimage. Further, it is also effective to combine the AC drive and the 360 Hz drive of the liquid crystal display device. That is, while the driving frequency of the liquid crystal display device is set to 360 Hz, the frequency of AC driving is set to an integral multiple or a fraction (for example, 30 Hz, 60 Hz, 120 Hz, 180 Hz) of flicker that appears due to AC driving. It can be reduced to a level not perceived by the human eye. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅙ times the cycle of the input image data.

Further, for example, in the first step, n=3, m=2, that is, the conversion ratio (n/m
) Is 3/2, the driving method is as shown at n=3 and m=2 in FIG.
At this time, the display frame rate is three times the frame rate of the input image data (three times speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 180 Hz (180 Hz drive). Then, for one input image data, the image is continuously displayed three times. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Where 3
In the case of the double speed drive, the quality of the moving image can be improved as compared with the case where the frame rate is lower than the triple speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is higher than the triple speed. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Further, it is also effective to combine the AC drive and the 180 Hz drive of the liquid crystal display device. That is, while the drive frequency of the liquid crystal display device is set to 180 Hz, the frequency of AC drive is set to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 180 Hz, etc.), so that flicker that appears due to AC drive is reduced. It can be reduced to a level not perceived by the human eye. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅓ times the cycle of the input image data.

Further, for example, in the first step, n=4, m=1, that is, the conversion ratio (n/m
) Is 4, the driving method is as shown at n=4 and m=1 in FIG. At this time, the display frame rate is eight times the frame rate of the input image data (eight speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 480 Hz (480 Hz drive). Then, for one input image data, the image is continuously displayed eight times. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Here, in the case of the 8× speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is lower than the 8× speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is higher than the 8× speed. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device,
Since the problem of insufficient write voltage due to the dynamic capacitance can be avoided, a particularly remarkable image quality improving effect can be obtained against obstacles such as tailing of a moving image and afterimage. Further, it is also effective to combine AC driving and 480 Hz driving of the liquid crystal display device. That is, by setting the drive frequency of the liquid crystal display device to 480 Hz, and setting the frequency of AC drive to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 240 Hz, etc.), flicker that appears due to AC drive is reduced. It can be reduced to a level that is not perceived by the human eye. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅛ times the cycle of input image data, the image quality can be improved.

Further, for example, in the first step, n=4, m=3, that is, the conversion ratio (n/m
) Is 4/3, the driving method is as shown at n=4 and m=3 in FIG.
At this time, the display frame rate is 8/3 times the frame rate of the input image data (8
/3x speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 160 Hz (160 Hz drive). Then, for the three input image data, the image is continuously displayed eight times. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Here, in the case of driving at 8/3 times speed, it is possible to improve the quality of moving images as compared with the case where the frame rate is smaller than 8/3 times speed, and it is possible to reduce power consumption and manufacturing cost as compared with the case where the frame rate is higher than 8/3 times speed. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages.
Further, it is also effective to combine the AC drive and 160 Hz drive of the liquid crystal display device. That is, by setting the drive frequency of the liquid crystal display device to 160 Hz and setting the frequency of AC drive to an integral multiple or a fraction thereof (for example, 40 Hz, 80 Hz, 160 Hz, 320 Hz, etc.), flicker that appears due to AC drive is reduced. It can be reduced to a level not perceived by the human eye. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅜ times the cycle of the input image data.

Further, for example, in the first step, n=5, m=1, that is, the conversion ratio (n/m
) Is 5, the driving method is as shown at n=5, m=1 in FIG. At this time, the display frame rate is 10 times the frame rate of the input image data (10× speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 600 Hz (600 Hz drive). Then, the image is displayed ten times in succession for one input image data. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. here,
When driving at 10× speed, the quality of moving images can be improved more than when the frame rate is lower than 10× speed, and power consumption and manufacturing cost can be reduced as compared to when the frame rate is higher than 10× speed. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, it is also effective to combine AC driving and 600 Hz driving of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 600 Hz and setting the frequency of AC driving to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 100 Hz, 120 Hz, etc.), flicker that appears due to AC driving is reduced. It can be reduced to a level not perceived by the human eye. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about 1/10 times the cycle of the input image data.

Further, for example, in the first step, n=5, m=2, that is, the conversion ratio (n/m
) Is 5/2, the driving method is as shown at n=5, m=2 in FIG.
At this time, the display frame rate is five times the frame rate of the input image data (five speed drive). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 300 Hz (300 Hz drive). Then, the image is displayed five times in succession for one input image data. At this time, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Here, in the case of driving at 5× speed, the quality of moving images can be improved as compared with the case where the frame rate is lower than 5× speed, and the power consumption and the manufacturing cost can be reduced as compared with the case of being higher than 5× speed. Furthermore, the second
Since the method of using the original image as it is as the sub-image is selected in the procedure 1 of the step, the operation of the circuit that creates the intermediate image by motion compensation can be stopped or the circuit itself can be omitted from the device. The power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Further, it is also effective to combine AC driving and 300 Hz driving of the liquid crystal display device. That is, while the drive frequency of the liquid crystal display device is 300 Hz, the frequency of the AC drive is an integral multiple or an integer fraction (
For example, by setting the frequency to 30 Hz, 50 Hz, 60 Hz, 100 Hz, etc., flicker that appears due to AC driving can be reduced to a level that is not perceived by human eyes. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about ⅕ times the cycle of input image data, the image quality can be improved.

In this way, in the procedure 1 in the second step, the method of using the original image as it is as the sub-image is selected,
In procedure 2 in the second step, the number of sub-images is determined to be 2,
In the procedure 3 in the second step, if it is determined that T1=T2=T/2, the first
Since the display frame rate can be further doubled as compared with the frame rate conversion of the conversion ratio determined by the values of n and m in the step, it is possible to further improve the quality of the moving image. Furthermore, the quality of the moving image can be improved as compared with the case where the display frame rate is smaller than the display frame rate, and the power consumption and the manufacturing cost can be reduced as compared with the case where the display frame rate is larger than the display frame rate.
Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. further,
By increasing the driving frequency of the liquid crystal display device and setting the frequency of AC driving to an integral multiple or a fraction thereof, it is possible to reduce flicker that appears due to AC driving to a level that is not perceived by human eyes. Furthermore, the response time of the liquid crystal element is
The image quality can be improved by applying it to a liquid crystal display device having a ratio of about 1/(twice the conversion ratio).

Although detailed description has been omitted, it is clear that the same advantages are obtained even in cases other than the conversion ratios raised above. For example, in the range where n is 10 or less, in addition to those listed above,
n=5, m=3, that is, conversion ratio (n/m)=5/3 (10/3 double speed drive, 200 Hz)
,
n=5, m=4, that is, conversion ratio (n/m)=5/4 (5/2 speed drive, 150 Hz),
n=6, m=1, that is, conversion ratio (n/m)=6 (12× speed drive, 720 Hz),
n=6, m=5, that is, conversion ratio (n/m)=6/5 (12/5 double speed drive, 144 Hz)
,
n=7, m=1, that is, conversion ratio (n/m)=7 (14× speed drive, 840 Hz),
n=7, m=2, that is, conversion ratio (n/m)=7/2 (7× speed drive, 420 Hz),
n=7, m=3, that is, conversion ratio (n/m)=7/3 (14/3 speed drive, 280 Hz)
,
n=7, m=4, that is, conversion ratio (n/m)=7/4 (7/2 speed drive, 210 Hz),
n=7, m=5, that is, conversion ratio (n/m)=7/5 (14/5 double speed drive, 168 Hz)
,
n=7, m=6, that is, conversion ratio (n/m)=7/6 (7/3 speed drive, 140 Hz),
n=8, m=1, that is, conversion ratio (n/m)=8 (16× speed drive, 960 Hz),
n=8, m=3, that is, conversion ratio (n/m)=8/3 (16/3 double speed drive, 320 Hz)
,
n=8, m=5, that is, conversion ratio (n/m)=8/5 (16/5 double speed drive, 192 Hz)
,
n=8, m=7, that is, conversion ratio (n/m)=8/7 (16/7 double speed drive, 137 Hz)
,
n=9, m=1, that is, conversion ratio (n/m)=9 (18× speed drive, 1080 Hz),
n=9, m=2, that is, conversion ratio (n/m)=9/2 (9×speed drive, 540 Hz),
n=9, m=4, that is, conversion ratio (n/m)=9/4 (9/2 double speed drive, 270 Hz),
n=9, m=5, that is, conversion ratio (n/m)=9/5 (18/5 speed drive, 216 Hz)
,
n=9, m=7, that is, conversion ratio (n/m)=9/7 (18/7 double speed drive, 154 Hz)
,
n=9, m=8, that is, conversion ratio (n/m)=9/8 (9/4 speed drive, 135 Hz),
n=10, m=1, that is, conversion ratio (n/m)=10 (20× speed drive, 1200 Hz),
n=10, m=3, that is, conversion ratio (n/m)=10/3 (20/3 speed drive, 400H)
z),
n=10, m=7, that is, conversion ratio (n/m)=10/7 (20/7 double speed drive, 171H
z),
n=10, m=9, that is, conversion ratio (n/m)=10/9 (20/9 double speed drive, 133H
z),
Combinations of the above are possible. Note that the notation of frequency is an example when the input frame rate is 60 Hz, and for other input frame rates, a value obtained by integrating twice the conversion ratio of each with the input frame rate is the drive frequency.

In addition, when n is an integer larger than 10, specific numbers of n and m are not given, but it is clear that the procedure in the second step can be applied to various n and m. ..

When J=2, it is particularly effective if the conversion ratio in the first step is larger than 2. This is because if the number of sub-images is made relatively small such as J=2 in the second step, the conversion ratio in the first step can be correspondingly increased. Such conversion ratios are 3, 4, 5, 5/2, 6, 7 when n is 10 or less.
, 7/2, 7/3, 8, 8/3, 9, 9/2, 9/4, 10 and 10/3.
When the display frame rate after the first step has such a value, by setting J=3 or more, an advantage due to the small number of sub-images in the second step (reduction of power consumption and manufacturing cost, etc.) In addition, it is possible to achieve the advantages of the high final display frame rate (improvement of moving image quality, reduction of flicker, etc.).

Here, in step 2, the number J of sub-images is determined to be 2, and in step 3, T ₁ =
Although the case where T ₂ =T/2 is determined has been described, it is obvious that the present invention is not limited to this.

For example, in the procedure 3 in the second step, if it is determined that T ₁ <T ₂ , the first sub-image can be made brighter and the second sub-image can be made darker. Furthermore, the second
When it is determined that T ₁ >T ₂ in the procedure 3 in the step of _1. , it is possible to make the first sub-image darker and the second sub-image brighter. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. However, when the method of using the original image as the sub image as it is is selected in the procedure 1 like the above-described driving method, the brightness of the sub image may be displayed as it is without being changed. This is because, in this case, since the images used as the sub-images are the same, the original image can be displayed properly regardless of the display timing of the sub-images.

Further, in the procedure 2, it is obvious that the number J of sub-images may be determined to a value other than 2 instead of 2. In this case, the display frame rate can be set to J times as high as the frame rate conversion of the conversion ratio determined by the values of n and m in the first step, so that the quality of the moving image is further improved. Is possible. Furthermore, the quality of the moving image can be improved as compared with the case where the display frame rate is smaller than the display frame rate, and the power consumption and the manufacturing cost can be reduced as compared with the case where the display frame rate is larger than the display frame rate. Furthermore, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected to stop the operation of the circuit that creates the intermediate image by motion compensation or omit the circuit itself from the device. Therefore, the power consumption and the manufacturing cost of the device can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, by increasing the driving frequency of the liquid crystal display device and making the frequency of AC driving an integral multiple or a fraction thereof, it is possible to reduce flicker that appears due to AC driving to a level that is not perceptible to human eyes. it can. Further, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about (1/(J times the conversion ratio)) times the cycle of the input image data.

For example, when J=3, it is possible to improve the quality of the moving image more than when the number of sub-images is less than 3, and to reduce power consumption and manufacturing cost more than when the number of sub-images is greater than 3. Have advantages. Furthermore, the response time of the liquid crystal element is equal to (1
The image quality can be improved by applying it to a liquid crystal display device having a ratio of about (/3 times the conversion ratio) times.

Further, for example, when J=4, the quality of the moving image can be improved more than when the number of sub-images is less than 4, and power consumption and manufacturing cost can be reduced more than when the number of sub-images is greater than 4. It has the advantage that it can. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is approximately (1/(4 times the conversion ratio)) times the cycle of the input image data, the image quality can be improved.

Further, for example, when J=5, the quality of the moving image can be improved more than when the number of sub-images is less than 5, and the power consumption and the manufacturing cost can be reduced more than when the number of sub-images is greater than 5. It has the advantage that it can. Further, by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about (1/(5 times the conversion ratio)) times the cycle of the input image data, the image quality can be improved.

Furthermore, if J is other than those listed above, it has similar advantages.

Note that when J=3 or more, the conversion ratio in the first step can take various values, but when the conversion ratio in the first step is relatively small (2 or less), J= Three
The above is effective. This is because if the display frame rate after the first step is relatively small, J can be correspondingly increased in the second step. Such a conversion ratio is 1, 2, 3/2, 4/3, when n is 10 or less,
5/3, 5/4, 6/5, 7/4, 7/5, 7/6, 8/7, 9/5, 9/7, 9/8,
10/7, 10/9. Of these, the conversion ratios are 1, 2, 3/2, 4/3, 5/
The case of 3, 5/4 is illustrated in FIG. As described above, when the display frame rate after the first step is a relatively small value, by setting J=3 or more, there is an advantage due to the small display frame rate in the first step (power consumption and manufacturing cost are reduced). (Reduction, etc.) and the advantage of the high final display frame rate (improvement of moving image quality, reduction of flicker, etc.) can be achieved at the same time.

Next, another example of the driving method determined by the procedure in the second step will be described.

In the procedure 1 in the second step, when the black insertion method is selected among the methods of distributing the brightness of the original image to the plurality of sub-images, the driving method is as follows.

The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially prepared at a constant cycle T,
The cycle T is divided into J (J is an integer of 2 or more) sub-image display periods,
The i-th image data is data that allows each of a plurality of pixels to have a unique brightness L,
The j-th (j is an integer of 1 or more and J or less) sub-image is configured by arranging a plurality of pixels each having a unique brightness L _j, and is displayed for the j-th sub-image display period T _j. Image,
A driving method of a display device, wherein L, T, L _j , and T _j are sub-image distribution conditions,
In at least one j, the brightness L _{j of} all pixels included in the j-th sub-image is L _j
=0.
Here, the original image data created in the first step can be used as the image data that is sequentially prepared in the constant cycle T. That is, all the display patterns mentioned in the description of the first step can be combined with the above driving method.

It is obvious that the driving method described above can be implemented by combining various n and m used in the first step.

When the number J of sub-images is determined to be 2 in the procedure 2 in the second step and T ₁ =T ₂ =T/2 is determined in the procedure 3, the driving method is shown in FIG. It will be something like.
Since the features and advantages of the driving method (display timings at various n and m) shown in FIG. 71 have already been described, a detailed description thereof will be omitted here. It is clear that among the methods of dividing the image into a plurality of sub-images, the black insertion method has the same advantage when the black insertion method is selected. For example, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Further, when the display frame rate is high, the quality of the moving image can be improved, and when the display frame rate is low, the power consumption and the manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, it is possible to reduce the flicker that appears due to AC driving so that it cannot be perceived by the human eye.

In the procedure 1 of the second step, among the methods of distributing the brightness of the original image to the plurality of sub-images, the characteristic advantage of the black insertion method being selected is that an intermediate image is created by motion compensation. Since the operation of the circuit can be stopped or the circuit itself can be omitted from the device,
That is, the power consumption and the manufacturing cost of the device can be reduced. Further, since the pseudo impulse type display method can be used regardless of the gradation value included in the image data, the quality of the moving image can be improved.

Here, in step 2, the number J of sub-images is determined to be 2, and in step 3, T ₁ =
Although the case where T ₂ =T/2 is determined has been described, it is obvious that the present invention is not limited to this.

For example, in the procedure 3 in the second step, if it is determined that T ₁ <T ₂ , the first sub-image can be made brighter and the second sub-image can be made darker. Furthermore, the second
When it is determined that T ₁ >T ₂ in the procedure 3 in the step of _1. , it is possible to make the first sub-image darker and the second sub-image brighter. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. However, if the black insertion method is selected among the methods of distributing the brightness of the original image to the plurality of sub-images in the procedure 1 as in the driving method described above, the brightness of the sub-image is not changed. Alternatively, it may be displayed as it is. because,
This is because in this case, if the brightness of the sub-image is not changed, the entire brightness of the original image is only displayed dark. That is, by positively using this method for controlling the brightness of the display device, it is possible to control the brightness while improving the quality of the moving image.

Further, in the procedure 2, it is obvious that the number J of sub-images may be determined to a value other than 2 instead of 2. Since the advantages in that case have already been described, a detailed description thereof will be omitted here, but in the procedure 1 in the second step, the black insertion method among the methods of distributing the brightness of the original image to the plurality of sub-images is Obviously, it has the same advantages when selected. For example, the response time of the liquid crystal element is (1/(J times the conversion ratio)) of the cycle of the input image data.
) The image quality can be improved by applying it to a liquid crystal display device which is about double the size.

Next, another example of the driving method determined by the procedure in the second step will be described.

In the procedure 1 in the second step, when the time division gradation control method is selected from among the methods of distributing the brightness of the original image to the plurality of sub-images, the driving method is as follows.

The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially prepared at a constant cycle T,
The cycle T is divided into J (J is an integer of 2 or more) sub-image display periods,
The i-th image data is data that allows each of a plurality of pixels to have a unique brightness L,
The maximum value of the specific brightness L is L _max ,
The j-th (j is an integer of 1 or more and J or less) sub-image is configured by arranging a plurality of pixels each having a unique brightness L _j, and is displayed for the j-th sub-image display period T _j. Image,
A driving method of a display device, wherein L, T, L _j , and T _j are sub-image distribution conditions,
In displaying the specific brightness L, from (j-1)×L _max /J to J×L _max
The adjustment of the brightness in the brightness range of /J is performed by adjusting the brightness in only one sub-image display period among the J sub-image display periods.
Here, the original image data created in the first step can be used as the image data that is sequentially prepared in the constant cycle T. That is, all the display patterns mentioned in the description of the first step can be combined with the above driving method.

It is obvious that the driving method described above can be implemented by combining various n and m used in the first step.

When the number J of sub-images is determined to be 2 in the procedure 2 in the second step and T ₁ =T ₂ =T/2 is determined in the procedure 3, the driving method is shown in FIG. It will be something like.
Since the features and advantages of the driving method (display timings at various n and m) shown in FIG. 71 have already been described, a detailed description thereof will be omitted here. It is obvious that the same advantages can be obtained even when the time division gradation control method is selected from among the methods of distributing the image data to a plurality of sub-images. For example, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Further, when the display frame rate is high, the quality of the moving image can be improved, and when the display frame rate is low, the power consumption and the manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, it is possible to reduce the flicker that appears due to AC driving so that it cannot be perceived by the human eye.

In the procedure 1 of the second step, among the methods of distributing the brightness of the original image to the plurality of sub-images, the characteristic advantage of the time-division gradation control method being selected is that the intermediate image It is possible to stop the operation of the circuit for creating the circuit or omit the circuit itself from the device, so that it is possible to reduce the power consumption and the manufacturing cost of the device. further,
Since a pseudo impulse type display method can be used, the quality of moving images can be improved and the brightness of the display device does not decrease, so that power consumption can be further reduced.

Here, in step 2, the number J of sub-images is determined to be 2, and in step 3, T ₁ =
Although the case where T ₂ =T/2 is determined has been described, it is obvious that the present invention is not limited to this.

For example, in the procedure 3 in the second step, if it is determined that T ₁ <T ₂ , the first sub-image can be made brighter and the second sub-image can be made darker. Furthermore, the second
When it is determined that T ₁ >T ₂ in the procedure 3 in the step of _1. , it is possible to make the first sub-image darker and the second sub-image brighter. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved.

Further, in the procedure 2, it is obvious that the number J of sub-images may be determined to a value other than 2 instead of 2. Since the advantages in that case have already been described, a detailed description thereof will be omitted here. Obviously, the same advantages are obtained when the control method is selected. For example, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about (1/(J times the conversion ratio)) times the cycle of the input image data.

Next, another example of the driving method determined by the procedure in the second step will be described.

In the procedure 1 in the second step, when the gamma complement method is selected among the methods of distributing the brightness of the original image to the plurality of sub-images, the driving method is as follows.

The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially prepared at a constant cycle T,
The cycle T is divided into J (J is an integer of 2 or more) sub-image display periods,
The i-th image data is data that allows each of a plurality of pixels to have a unique brightness L,
The j-th (j is an integer of 1 or more and J or less) sub-image is configured by arranging a plurality of pixels each having a unique brightness L _j, and is displayed for the j-th sub-image display period T _j. Image,
A driving method of a display device, wherein L, T, L _j , and T _j are sub-image distribution conditions,
In each sub-image, the characteristics of the change in brightness with respect to gradation are shifted from linear, and the total amount of brightness shifted from linear to bright and the total amount of brightness shifted from linear to dark are , And is almost equal in all gradations.
Here, the original image data created in the first step can be used as the image data that is sequentially prepared in the constant cycle T. That is, all the display patterns mentioned in the description of the first step can be combined with the above driving method.

It is obvious that the driving method described above can be implemented by combining various n and m used in the first step.

When the number J of sub-images is determined to be 2 in the procedure 2 in the second step and T ₁ =T ₂ =T/2 is determined in the procedure 3, the driving method is shown in FIG. It will be something like.
Since the features and advantages of the driving method (display timings at various n and m) shown in FIG. 71 have already been described, detailed description thereof will be omitted here, but in the procedure 1 in the second step, the brightness of the original image is reduced. It is clear that among the methods of dividing the image into a plurality of sub-images, the same advantage can be obtained when the gamma complement method is selected. For example, when the interpolated image in the first step is an intermediate image obtained by motion compensation, the motion of the moving image can be smoothed, so that the quality of the moving image can be significantly improved. Further, when the display frame rate is high, the quality of the moving image can be improved, and when the display frame rate is low, the power consumption and the manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient write voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improving effect is obtained against problems such as trailing of moving images and afterimages. Furthermore, it is possible to reduce the flicker that appears due to AC driving so that it cannot be perceived by the human eye.

In the procedure 1 of the second step, among the methods of distributing the brightness of the original image to the plurality of sub-images, the characteristic advantage of the gamma complement method being selected is that an intermediate image is created by motion compensation. Since the operation of the circuit can be stopped or the circuit itself can be omitted from the device, power consumption and manufacturing cost of the device can be reduced. Further, since the pseudo impulse type display method can be used regardless of the gradation value included in the image data, the quality of the moving image can be improved. Further, the sub-image may be obtained by directly performing gamma conversion on the image data. In this case, there is an advantage that the gamma value can be controlled in various ways depending on the size of the motion of the moving image. Further, the image data may not be directly gamma-converted, but the sub-image having the changed gamma value may be obtained by changing the reference voltage of the digital-analog conversion circuit (DAC). In this case, since the image data is not directly subjected to gamma conversion, the circuit that performs gamma conversion can be stopped or the circuit itself can be omitted from the device, so that power consumption and manufacturing cost of the device can be reduced. .. Further, in the gamma complementation method, since the change in the brightness L _j of each sub-image with respect to the gradation follows the gamma curve, each sub-image can display the gradation by itself, and finally the human It has the advantage that the quality of the image perceived by the eye is also improved.

Here, in step 2, the number J of sub-images is determined to be 2, and in step 3, T ₁ =
Although the case where T ₂ =T/2 is determined has been described, it is obvious that the present invention is not limited to this.

For example, in the procedure 3 in the second step, if it is determined that T ₁ <T ₂ , the first sub-image can be made brighter and the second sub-image can be made darker. Furthermore, the second
When it is determined that T ₁ >T ₂ in the procedure 3 in the step of _1. , it is possible to make the first sub-image darker and the second sub-image brighter. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. As in the above driving method, the procedure 1
In the method 1, when the gamma method is selected among the methods of distributing the brightness of the original image to the plurality of sub-images, the gamma value may be changed when the brightness of the sub-image is changed. That is, the gamma value may be determined according to the display timing of the second sub-image. By doing so, the circuit that changes the brightness of the entire image can be stopped or the circuit itself can be omitted from the device, so that the power consumption and the manufacturing cost of the device can be reduced.

Further, in the procedure 2, it is obvious that the number J of sub-images may be determined to a value other than 2 instead of 2. Since the advantages in that case have already been described, a detailed description thereof will be omitted here. Obviously, the same advantages are obtained when the control method is selected. For example, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about (1/(J times the conversion ratio)) times the cycle of the input image data.

Next, another example of the driving method determined by the procedure in the second step will be described in detail.

In the procedure 1 in the second step, a method of using the intermediate image obtained by motion compensation as a sub image is selected,
In procedure 2 in the second step, the number of sub-images is determined to be 2,
In the procedure 3 in the second step, if T1=T2=T/2 is determined, the second
The driving method determined by the procedure in the step is as follows.

The i-th (i is a positive integer) image data,
The i+1th image data and are sequentially prepared at a constant cycle T,
The k-th (k is a positive integer) image,
The (k+1)th image,
A method for driving a display device for sequentially displaying a k+2th image and an interval of 1/2 times the cycle of original image data,
The k-th image is displayed according to the i-th image data,
The k+1st image is displayed according to image data corresponding to a movement obtained by halving the movement from the i-th image data to the i+1-th image data,
The k+2nd image is displayed according to the i+1th image data.
Here, the original image data created in the first step can be used as the image data that is sequentially prepared in the constant cycle T. That is, all the display patterns mentioned in the description of the first step can be combined with the above driving method.

It is obvious that the driving method described above can be implemented by combining various n and m used in the first step.

A characteristic advantage of the method of using the intermediate image obtained by motion compensation as a sub-image in the procedure 1 in the second step is that the intermediate image obtained by motion compensation is selected in the procedure of the first step. When the interpolation image is used, the method of obtaining the intermediate image used in the first step can be used as it is in the second step. That is, since the circuit for obtaining the intermediate image by motion compensation can be used not only in the first step but also in the second step, the circuit can be effectively used and the processing efficiency can be improved. Moreover, since the motion of the image can be made smoother, the quality of the moving image can be further improved.

Here, in step 2, the number J of sub-images is determined to be 2, and in step 3, T ₁ =
Although the case where T ₂ =T/2 is determined has been described, it is obvious that the present invention is not limited to this.

For example, in the procedure 3 in the second step, if it is determined that T ₁ <T ₂ , the first sub-image can be made brighter and the second sub-image can be made darker. Furthermore, the second
When it is determined that T ₁ >T ₂ in the procedure 3 in the step of _1. , it is possible to make the first sub-image darker and the second sub-image brighter. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. By doing so, the original image can be properly perceived by human eyes, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. As in the driving method above, in step 2,
When the method of using the intermediate image obtained by motion compensation as the sub-image is selected, the brightness of the sub-image need not be changed. This is because the image in the intermediate state is completed as an image by itself, and even if the display timing of the second sub image changes, it does not change as an image perceived by human eyes. In this case, the circuit that changes the brightness of the entire image can be stopped or the circuit itself can be omitted from the device, so that the power consumption and the manufacturing cost of the device can be reduced.

Further, in the procedure 2, it is obvious that the number J of sub-images may be determined to a value other than 2 instead of 2. Since the advantages in that case have already been described, a detailed description thereof will be omitted here, but the same applies when the method of using the intermediate image obtained by motion compensation as the sub-image is selected in the procedure 1 in the second step. It has obvious advantages. For example, the image quality can be improved by applying it to a liquid crystal display device in which the response time of the liquid crystal element is about (1/(J times the conversion ratio)) times the cycle of the input image data.

Next, with reference to FIG. 73, a specific example of the frame rate conversion method when the input frame rate and the display frame rate are different will be described. In the methods shown in FIGS. 73A to 73C, it is assumed that the circular area on the image is an area whose position changes depending on the frame, and the triangular area on the image is an area whose position hardly changes depending on the frame. There is. However,
This is an example for explanation, and the displayed image is not limited to this. The methods of FIGS. 73A to 73C can be applied to various images.

FIG. 73A shows a case where the display frame rate is twice the input frame rate (the conversion ratio is 2). When the conversion ratio is 2, there is an advantage that the quality of the moving image can be improved more than when the conversion ratio is smaller than 2. Further, when the conversion ratio is 2, there is an advantage that the power consumption and the manufacturing cost can be reduced more than when the conversion ratio is larger than 2. FIG. 73 (
A) is a schematic representation of how the displayed image changes with time, with the horizontal axis representing time. Here, the image of interest is referred to as the p-th image (p is a positive integer). Then, the image displayed next to the image of interest is the (p+1)th image,
For convenience, it is indicated how far from the image of interest the image displayed before the image of interest is displayed, such as the (p-1)th image. I will. The image 7301 is the p-th image, the image 7302 is the (p+1)th image, and the image 730.
3 is the (p+2)th image, image 7304 is the (p+3)th image, and image 7305 is the (p+2)th image.
It is assumed that the image is 4). The period Tin represents the cycle of input image data. Note that FIG. 73A illustrates the case where the conversion ratio is 2, and thus the period Tin is twice as long as the period from the display of the p-th image to the display of the (p+1)th image. It becomes the length.

Here, the (p+1)th image 7302 corresponds to the (p+2)th image 7301 from the pth image 7301.
The image may be created so as to be in an intermediate state between the pth image 7301 and the (p+2)th image 7303 by detecting the amount of change in the images up to 303. In FIG. 73A, an intermediate state image is represented by a region (circular region) whose position changes depending on the frame and a region (triangular region) whose position hardly changes depending on the frame. That is, the position of the circular area in the (p+1)th image 7302 is the same as that of the pth image 7301.
And the position in the (p+2)th image 7303. That is, the (p+1)th image 7302 is obtained by performing motion compensation and interpolating image data. In this way, a smooth display can be performed by performing motion compensation on a moving object on the image and interpolating the image data.

Furthermore, the (p+1)th image 7302 is an image in which the luminance of the image is controlled according to a certain rule after being created so as to be in an intermediate state between the pth image 7301 and the (p+2)th image 7303. May be. The certain rule is, for example, as shown in FIG. 73(A), the p-th image 73.
When the representative luminance of 01 is L and the representative luminance of the (p+1)th image 7302 is Lc, L and Lc may have a relationship of L>Lc. Desirably, 0.1 L<Lc<0.
There may be a relationship of 8L. More preferably, there may be a relationship of 0.2L<Lc<0.5L. Alternatively, on the contrary, there may be a relationship of L<Lc between L and Lc. Desirably, there may be a relationship of 0.1Lc<L<0.8Lc. More preferably, 0
． There may be a relationship of 2Lc<L<0.5Lc. By doing so, the display can be made to be a pseudo impulse type display, so that the afterimage of the eyes can be suppressed.

The typical brightness of the image will be described later in detail with reference to FIG.

In this way, there are two different causes for the motion blur (the image movement is not smooth,
And the afterimage of the eyes) can be solved at the same time, so that the motion blur can be significantly reduced.

Furthermore, the (p+3)th image 7304 may also be created from the (p+2)th image 7303 and the (p+4)th image 7305 using a similar method. That is, the (p
+3) image 7304 is the (p+2)th image 7303 to the (p+4)th image 7305.
Up to the (p+2)th image 7303 and the (p+4)th image 7303.
The image 7305 may be an image created so as to be in an intermediate state of the image 7305, and the image brightness may be controlled according to a certain rule.

FIG. 73B shows the case where the display frame rate is three times the input frame rate (the conversion ratio is 3). FIG. 73(B) schematically shows how the displayed image changes with time, with the horizontal axis representing time. The image 7311 is the p-th image, the image 7312 is the (p+1)th image, the image 7313 is the (p+2)th image, the image 7314 is the (p+3)th image, and the image 7315 is the (p+4)th image, image 7316. Is the (p+5)th image, image 7
It is assumed that 317 is the (p+6)th image. The period Tin represents the cycle of input image data. Note that FIG. 73B shows the case where the conversion ratio is 3, and thus the period Tin is
The period from the display of the pth image to the display of the (p+1)th image is three times as long as the period.

Here, the (p+1)th image 7312 and the (p+2)th image 7313 are detected by detecting the amount of change in the images from the pth image 7311 to the (p+3)th image 7314. Alternatively, the image may be an image created so as to be in an intermediate state between the (p+3)th image 7314. In FIG. 73B, the state of the image in the intermediate state is represented by a region (circular region) whose position changes depending on the frame and a region (triangular region) whose position hardly changes depending on the frame. That is, the (p+1)th image 7312 and the (p+)th image 7312
The position of the circular area in the image 7313 of 2) is the position in the p-th image 7311,
The position is an intermediate position between the positions in the (p+3)th image 7314. Specifically, when the amount of movement of the circular region detected from the p-th image 7311 and the (p+3)th image 7314 is X, the position of the circular region in the (p+1)th image 7312 is It may be a position displaced by (1/3)X from the position in the p-th image 7311. Furthermore, the position of the circular region in the (p+2)th image 7313 may be a position displaced by (2/3)X from the position in the pth image 7311. That is, the (p+1)th image 7
The 312 and the (p+2)th image 7313 are obtained by performing motion compensation and interpolating image data. In this way, by performing motion compensation on a moving object on the image and interpolating the image data, a smooth display can be performed.

Furthermore, the (p+1)th image 7312 and the (p+2)th image 7313 are created so as to be in an intermediate state between the pth image 7311 and the (p+3)th image 7314, and the brightness of the images is constant. It may be an image controlled by the rule. For example, the fixed rule is shown in FIG.
3B, the representative luminance of the p-th image 7311 is L, and the (p+1)-th image 731 is L.
When the representative luminance of 2 is Lc1 and the representative luminance of the (p+2)th image 7313 is Lc2, L>Lc1 or L>Lc2 or Lc1=Lc2 in L, Lc1, and Lc2.
There may be a relationship. Desirably, there may be a relationship of 0.1L<Lc1=Lc2<0.8L. More desirably, there may be a relationship of 0.2L<Lc=Lc2<0.5L. Or, conversely, in L, Lc1 and Lc2, L<Lc1 or L<Lc2
Alternatively, there may be a relationship of Lc1=Lc2. Desirably, 0.1Lc1=0.1L
There may be a relationship of c2<L<0.8Lc1=0.8Lc2. More preferably,
There may be a relationship of 0.2Lc1=0.2Lc2<L<0.5Lc1=0.5Lc2. By doing so, the display can be made to be a pseudo impulse type display, so that the afterimage of the eyes can be suppressed. Alternatively, images whose brightness is changed may appear alternately. By doing so, the period in which the luminance changes can be shortened, so that flicker can be reduced.

In this way, there are two different causes for the motion blur (the image movement is not smooth,
And the afterimage of the eyes) can be solved at the same time, so that the motion blur can be significantly reduced.

Further, the (p+4)th image 7315 and the (p+5)th image 7316 may be created from the (p+3)th image 7314 and the (p+6)th image 7317 by using a similar method. That is, the (p+4)th image 7315 and the (p+5)th image 7315
16 is in an intermediate state between the (p+3)th image 7314 and the (p+6)th image 7317 by detecting the amount of change in the images from the (p+3)th image 7314 to the (p+6)th image 7317. The image thus created may be an image in which the brightness of the image is controlled according to a certain rule.

Note that when the method of FIG. 73B is used, the display frame rate is high, so that the movement of the image can follow the movement of the eye well, and the movement of the image can be displayed smoothly, so that the moving image is blurred. Can be significantly reduced.

In FIG. 73C, the display frame rate is 1.5 times the input frame rate (conversion ratio 1.5).
) Represents the case. FIG. 73(C) schematically shows how the displayed image changes with time, with the horizontal axis representing time. Image 7321 is the p-th image, image 732.
2 is the (p+1)th image, image 7323 is the (p+2)th image, and image 7324 is the (p+)th image.
It is assumed that the image is 3). Note that the image 7325 is input image data and may be used for creating the (p+1)th image 7322 and the (p+2)th image 7323, although it may not be actually displayed. The period Tin represents the cycle of input image data. Note that FIG. 73C shows the case where the conversion ratio is 1.5; therefore, the period Tin is
The period from the display of the pth image to the display of the (p+1)th image is 1.5 times the period.

Here, for the (p+1)th image 7322 and the (p+2)th image 7323, the amount of change in the image from the pth image 7321 to the (p+3)th image 7324 via the image 7325 is detected. , The p-th image 7321 and the (p+3)th image 7324 may be in an intermediate state. In FIG. 73C, the state of the image in the intermediate state is represented by a region (circular region) whose position changes depending on the frame and a region (triangular region) whose position hardly changes depending on the frame. That is, the positions of the circular regions in the (p+1)th image 7322 and the (p+2)th image 7323 are the p-th image 7
It is an intermediate position between the position in 321 and the position in the (p+3)th image 7324. That is, the (p+1)th image 7322 and the (p+2)th image 7323 are obtained by performing motion compensation and interpolating image data. In this way, by performing motion compensation on a moving object on the image and interpolating the image data, a smooth display can be performed.

Furthermore, the (p+1)th image 7322 and the (p+2)th image 7323 are created so as to be in an intermediate state between the pth image 7321 and the (p+3)th image 7324, and the brightness of the images is constant. It may be an image controlled by the rule. For example, the fixed rule is shown in FIG.
3(C), the representative luminance of the p-th image 7321 is L, and the (p+1)-th image 732 is
When the representative luminance of 2 is Lc1 and the representative luminance of the (p+2)th image 7323 is Lc2, L>Lc1 or L>Lc2 or Lc1=Lc2 in L, Lc1, and Lc2.
There may be a relationship. Desirably, there may be a relationship of 0.1L<Lc1=Lc2<0.8L. More desirably, there may be a relationship of 0.2L<Lc=Lc2<0.5L. Or, conversely, in L, Lc1 and Lc2, L<Lc1 or L<Lc2
Alternatively, there may be a relationship of Lc1=Lc2. Desirably, 0.1Lc1=0.1L
There may be a relationship of c2<L<0.8Lc1=0.8Lc2. More preferably,
There may be a relationship of 0.2Lc1=0.2Lc2<L<0.5Lc1=0.5Lc2. By doing so, the display can be made to be a pseudo impulse type display, so that the afterimage of the eyes can be suppressed. Alternatively, images whose brightness is changed may appear alternately. By doing so, the period in which the luminance changes can be shortened, so that flicker can be reduced.

In this way, there are two different causes for the motion blur (the image movement is not smooth,
And the afterimage of the eyes) can be solved at the same time, so that the motion blur can be significantly reduced.

Note that when the method in FIG. 73C is used, the display frame rate is low, so that the time for writing a signal in the display device can be extended. Therefore, the clock frequency of the display device can be reduced, so that power consumption can be reduced. Moreover, since the processing speed for motion compensation can be slowed down, power consumption can be reduced.

Next, with reference to FIG. 74, typical brightness of an image will be described. 74A to 74D
The diagram shown in () schematically shows the temporal change of the displayed image with the horizontal axis representing time. FIG. 74(E) is an example of a method for measuring the luminance of an image in a certain area.

As a method of measuring the brightness of an image, there is a method of individually measuring the brightness of each pixel forming the image. Using this method, it is possible to measure the luminance precisely in the details of the image.

However, since the method of individually measuring the brightness of each pixel forming the image requires a great deal of labor, another method may be used. Another method for measuring the brightness of an image is to focus on a certain area in the image and measure the average brightness of the area. By this method, the brightness of the image can be easily measured. In the present embodiment, the brightness obtained by the method of measuring the average brightness of a certain area in the image will be referred to as the typical brightness of the image for convenience.

Then, in order to obtain a representative brightness of the image, which region in the image is focused on will be described below.

FIG. 74A shows an example of a method in which the luminance of a region (triangular region) whose position does not change substantially with respect to the change of the image is set as the representative luminance of the image. The period Tin is the cycle of the input image data, the image 7401 is the p-th image, the image 7402 is the (p+1)th image, the image 7403 is the (p+2)th image, and the first region 7404 is the brightness in the p-th image 7401. The measurement region, the second region 7405, is the luminance measurement region in the (p+1)th image 7402, and the third region 74.
06 represents the luminance measurement area in the (p+2)th image 7403, respectively. Here, the first to third regions may be approximately the same in terms of spatial position in the device.
That is, by measuring the typical brightness of the image in the first to third regions, the time change of the typical brightness of the image can be obtained.

By measuring the typical brightness of the image, it is possible to determine whether the display is pseudo impulse type. For example, let L be the brightness measured in the first region 7404, and
When Lc is the luminance measured in the region 7405 of L, if Lc<L, it can be said that the display is pseudo impulse type. At such times, it can be said that the quality of the moving image is improving.

In the brightness measurement area, the image quality can be improved when the typical brightness change amount (relative brightness) of the image with respect to time change is in the following range. As the relative brightness, for example, the first area 7404 and the second area 7405, and the second area 7405 and the third area 7 are used.
406, and the ratio of the smaller luminance to the larger luminance can be set for each of the first region 7404 and the third region 7406. That is, when the representative amount of change in luminance of the image with respect to time change is 0, the relative luminance is 100%. And the relative brightness is 8
If it is 0% or less, the quality of the moving image can be improved. In particular, if the relative brightness is 50% or less, the quality of moving images can be significantly improved. Furthermore, if the relative brightness is 10% or more, power consumption can be reduced and flicker can be suppressed. In particular, if the relative brightness is 20% or more, power consumption and flicker can be significantly reduced. That is, the relative brightness is 10% or more and 80
When it is at most %, the quality of the moving image can be improved, and power consumption and flicker can be reduced. Furthermore, if the relative luminance is 20% or more and 50% or less, the quality of moving images can be significantly improved, and power consumption and flicker can be significantly reduced.

FIG. 74(B) shows an example of a method of measuring the luminance of the area divided into tiles and setting the average value thereof as the representative luminance of the image. The period Tin is the cycle of the input image data, the image 7411.
Is the p-th image, the image 7412 is the (p+1)th image, the image 7413 is the (p+2)th image, the first region 7414 is the luminance measurement region in the p-th image 7411, and the second region 7415.
Is the luminance measurement region in the (p+1)th image 7412, and the third region 7416 is the (p+2)th region.
), the luminance measurement area in the image 7413 is shown. Here, the first to third
The areas may be approximately the same in terms of spatial position in the device. That is, by measuring the typical brightness of the image in the first to third regions, the time change of the typical brightness of the image can be obtained.

By measuring the typical brightness of the image, it is possible to determine whether the display is pseudo impulse type. For example, when the average value of the brightness measured in the first area 7414 in all the areas is L and the average value of the brightness measured in the second area 7415 in the area is Lc, Lc<L is satisfied. For example, it can be said that the display is pseudo impulse type.
At such times, it can be said that the quality of the moving image is improving.

In the brightness measurement area, the image quality can be improved when the typical brightness change amount (relative brightness) of the image with respect to time change is in the following range. As the relative brightness, for example, the first area 7414 and the second area 7415, and the second area 7415 and the third area 7 are used.
416, the ratio of the smaller luminance to the larger luminance can be set for each of the first region 7414 and the third region 7416. That is, when the representative amount of change in luminance of the image with respect to time change is 0, the relative luminance is 100%. And the relative brightness is 8
If it is 0% or less, the quality of the moving image can be improved. In particular, if the relative brightness is 50% or less, the quality of moving images can be significantly improved. Furthermore, if the relative brightness is 10% or more, power consumption can be reduced and flicker can be suppressed. In particular, if the relative brightness is 20% or more, power consumption and flicker can be significantly reduced. That is, the relative brightness is 10% or more and 80
When it is at most %, the quality of the moving image can be improved, and power consumption and flicker can be reduced. Furthermore, if the relative luminance is 20% or more and 50% or less, the quality of moving images can be significantly improved, and power consumption and flicker can be significantly reduced.

FIG. 74C shows an example of a method of measuring the luminance of the central region of the image and setting the average value thereof as the representative luminance of the image. The period Tin is the cycle of the input image data, the image 7421 is the p-th image, the image 7422 is the (p+1)th image, the image 7423 is the (p+2)th image, and the first region 7424 is the brightness in the p-th image 7421. The measurement region, the second region 7425 is the (p
The luminance measurement region in the (+1)th image 7422 and the third region 7426 represent the luminance measurement region in the (p+2)th image 7423, respectively.

By measuring the typical brightness of the image, it is possible to determine whether the display is pseudo impulse type. For example, let L be the brightness measured in the first region 7424, and
When Lc is the luminance measured in the area 7425 of L, if Lc<L, it can be said that the display is pseudo impulse type. At such times, it can be said that the quality of the moving image is improving.

In the brightness measurement area, the image quality can be improved when the typical brightness change amount (relative brightness) of the image with respect to time change is in the following range. As the relative brightness, for example, the first area 7424 and the second area 7425, and the second area 7425 and the third area 7 are used.
426, the ratio of the smaller luminance to the larger luminance can be set for each of the first region 7424 and the third region 7426. That is, when the representative amount of change in luminance of the image with respect to time change is 0, the relative luminance is 100%. And the relative brightness is 8
If it is 0% or less, the quality of the moving image can be improved. In particular, if the relative brightness is 50% or less, the quality of moving images can be significantly improved. Furthermore, if the relative brightness is 10% or more, power consumption can be reduced and flicker can be suppressed. In particular, if the relative brightness is 20% or more, power consumption and flicker can be significantly reduced. That is, the relative brightness is 10% or more and 80
When it is at most %, the quality of the moving image can be improved, and power consumption and flicker can be reduced. Furthermore, if the relative luminance is 20% or more and 50% or less, the quality of moving images can be significantly improved, and power consumption and flicker can be significantly reduced.

FIG. 74D illustrates an example of a method in which the luminance of a plurality of points sampled from the entire image is measured and the average value thereof is used as the representative luminance of the image. The period Tin is the cycle of the input image data,
The image 7431 is the p-th image, the image 7432 is the (p+1)th image, and the image 7433 is the (p-th) image.
+2) image, the first area 7434 is the luminance measurement area in the p-th image 7431, the second area 7435 is the luminance measurement area in the (p+1)th image 7432, and the third area 7436.
Represents the luminance measurement region in the (p+2)th image 7433.

By measuring the typical brightness of the image, it is possible to determine whether the display is pseudo impulse type. For example, when the average value of the brightness measured in the first area 7434 in all the areas is L and the average value of the brightness measured in the second area 7435 in the area is Lc, Lc<L For example, it can be said that the display is pseudo impulse type.
At such times, it can be said that the quality of the moving image is improving.

In the brightness measurement area, the image quality can be improved when the typical brightness change amount (relative brightness) of the image with respect to time change is in the following range. As the relative luminance, for example, the first area 7434 and the second area 7435, and the second area 7435 and the third area 7 are used.
436, the ratio of the smaller luminance to the larger luminance can be set for each of the first region 7434 and the third region 7436. That is, when the representative amount of change in luminance of the image with respect to time change is 0, the relative luminance is 100%. And the relative brightness is 8
If it is 0% or less, the quality of the moving image can be improved. In particular, if the relative brightness is 50% or less, the quality of moving images can be significantly improved. Furthermore, if the relative brightness is 10% or more, power consumption can be reduced and flicker can be suppressed. In particular, if the relative brightness is 20% or more, power consumption and flicker can be significantly reduced. That is, the relative brightness is 10% or more and 80
When it is at most %, the quality of the moving image can be improved, and power consumption and flicker can be reduced. Furthermore, if the relative luminance is 20% or more and 50% or less, the quality of moving images can be significantly improved, and power consumption and flicker can be significantly reduced.

FIG. 74(E) is a diagram showing a measuring method in the luminance measurement region in the diagrams shown in FIGS. 74(A) to 74(D). An area 7441 is a luminance measurement area of interest, and a point 7442 is a luminance measurement point in the luminance measurement area 7441. A luminance measurement device with high time resolution may have a small measurement target range. Therefore, when the region 7441 is large, the region 7441 is not measured, instead of measuring the entire region. The brightness of the region 7441 may be obtained by measuring at a plurality of points without unevenness in the shape.

If the image has a combination of three primary colors of R, G, and B, the measured luminance is R, G.
, B may be combined brightness, R and G combined brightness, G and B combined brightness, B and R combined brightness, and R, G, and B respectively. It may be brightness.

Next, a method of detecting the movement of the image included in the input image data and creating an intermediate state image,
A method of controlling the driving method according to the movement of the image included in the input image data and the like will be described.

An example of a method for detecting an image motion included in input image data and creating an image in an intermediate state will be described with reference to FIG. FIG. 75A shows a case where the display frame rate is twice the input frame rate (the conversion ratio is 2). FIG. 75(A) schematically shows a method for detecting the movement of an image with the horizontal axis as time. The period Tin is the cycle of input image data, the image 7501 is the p-th image, the image 7502 is the (p+1)th image,
The image 7503 represents the (p+2)th image, respectively. Further, in the image, as a region that does not depend on time, a first region 7504, a second region 7505, and a third region 750 are included.
6 is provided.

First, in the (p+2)th image 7503, the image is divided into a plurality of tile-shaped regions,
Focus on the image data in the third area 7506, which is one of the areas.

Next, in the p-th image 7501, a third region 750 centered on the third region 7506
Focus on a range greater than 6. Here, the third region 7 centered on the third region 7506
The range larger than 506 is the data search range. The data search range is 7507 in the horizontal direction (X direction) and 7508 in the vertical direction (Y direction). The horizontal range 7507 and the vertical range 7508 of the data search range may be a range obtained by expanding the horizontal range and the vertical range of the third area 7506 by about 15 pixels.

Then, within the data search range, an area having image data most similar to the image data in the third area 7506 is searched. As the search method, the least square method or the like can be used. As a result of the search, the first area 7504 is derived as an area having the most similar image data.

Next, a vector 7509 is derived as an amount representing the difference in position between the derived first area 7504 and the third area 7506. The vector 7509 will be called a motion vector.

Then, in the (p+1)th image 7502, the vector 7510 obtained from the motion vector 7509, the image data in the third region 7506 in the (p+2)th image 7503, and the first image in the pth image 7501. A second area 7505 is formed by the image data in the area 7504.

Here, the vector 7510 obtained from the motion vector 7509 will be called a displacement vector. The displacement vector 7510 has a role of determining a position where the second region 7505 is formed. The second region 7505 is formed at a position separated from the third region 7506 by the displacement vector 7510. The displacement vector 7510 has a coefficient (1/2) added to the motion vector 7509.
It may be the amount multiplied by.

The image data in the second area 7505 in the (p+1)th image 7502 is the (p+2)th image data.
) Image 7503 in the third region 7506 and the p-th image 7501 in the first region 7504 may be determined by the image data. For example,
The image data in the second area 7505 in the (p+1)th image 7502 is the (p+2)th image data.
), the average value of the image data in the third area 7506 in the image 7503 and the image data in the first area 7504 in the p-th image 7501 may be used.

Thus, corresponding to the third region 7506 in the (p+2)th image 7503,
A second region 7505 in the (p+1)th image 7502 can be formed. It should be noted that by performing the above processing for other regions in the (p+2)th image 7503,
(p+2) image 7503 and p-th image 7501 are in an intermediate state, and the (p+1)th image 7
502 can be formed.

FIG. 75B shows a case where the display frame rate is three times the input frame rate (the conversion ratio is 3). FIG. 75(B) schematically shows a method of detecting the movement of an image with the horizontal axis as time. The period Tin is the cycle of the input image data, the image 7511.
Represents the p-th image, the image 7512 represents the (p+1)th image, the image 7513 represents the (p+2)th image, and the image 7514 represents the (p+3)th image. In addition, in the image, as a region that does not depend on time, a first region 7515, a second region 7516, and a third region 7517.
And a fourth region 7518 is provided.

First, in the (p+3)th image 7514, the image is divided into a plurality of tile-shaped regions,
Focus on the image data in the fourth area 7518, which is one of the areas.

Next, in the p-th image 7511, a fourth region 751 centered on the fourth region 7518
Focus on a range greater than eight. Here, the fourth region 7 centered on the fourth region 7518
The range larger than 518 is the data search range. The data search range is 7519 in the horizontal direction (X direction) and 7520 in the vertical direction (Y direction). The horizontal range 7519 and the vertical range 7520 of the data search range may be a range obtained by expanding the horizontal range and the vertical range of the fourth region 7518 by about 15 pixels.

Then, within the data search range, an area having image data most similar to the image data in the fourth area 7518 is searched. As the search method, the least square method or the like can be used. As a result of the search, it is assumed that the first area 7515 is derived as an area having the most similar image data.

Next, a vector 7521 is derived as an amount representing the difference in position between the derived first region 7515 and fourth region 7518. The vector 7521 will be called a motion vector.

Then, in the (p+1)th image 7512 and the (p+2)th image 7513,
By the vectors 7522 and 7523 obtained from the motion vector 7521, the image data in the fourth area 7518 in the (p+3)th image 7515, and the image data in the first area 7515 in the pth image 7511, The second region 7516 and the third region 7517 are formed.

Here, the vector 7522 obtained from the motion vector 7521 will be referred to as a first displacement vector. Further, the vector 7523 will be referred to as a second displacement vector. The first displacement vector 7522 has a role of determining a position where the second region 7516 is formed. The second region 7516 is formed at a position separated from the fourth region 7518 by the first displacement vector 7522. The displacement vector 7522 may be an amount obtained by multiplying the motion vector 7521 by (1/3). Further, the second displacement vector 7523 has a role of determining a position where the third region 7517 is formed. The third region 7517 is formed at a position separated from the fourth region 7518 by the second displacement vector 7523. The displacement vector 7523 may be an amount obtained by multiplying the motion vector 7521 by (2/3).

The image data in the second area 7516 in the (p+1)th image 7512 is the (p+3)th image data.
) Image 7514 in the fourth area 7518 and the p-th image 7511 in the first area 7515 may be determined by the image data. For example,
The image data in the second area 7516 in the (p+1)th image 7512 is the (p+3)th image data.
), the average value of the image data in the fourth region 7518 in the image 7514 and the image data in the first region 7515 in the p-th image 7511 may be used.

The image data in the third region 7517 in the (p+2)th image 7513 is the (p+3)th image data.
) Image 7514 in the fourth area 7518 and the p-th image 7511 in the first area 7515 may be determined by the image data. For example,
The image data in the third region 7517 in the (p+2)th image 7513 is the (p+3)th image data.
), the average value of the image data in the fourth region 7518 in the image 7514 and the image data in the first region 7515 in the p-th image 7511 may be used.

Thus, corresponding to the fourth region 7518 in the (p+3)th image 7514,
The second region 7516 in the (p+1)th image 7502 and the (p+2)th image 7
A third region 7517 at 513 can be formed. In addition, the above process
(p+3) image 7514 is also performed in another area, so that the (p+3)th image 751
The (p+1)th image 7512 and the (p+)th image 7512, which are in the intermediate state between the 4th and the pth image 7511.
The image 7513 of 2) can be formed.

Next, with reference to FIG. 76, an example of a circuit that detects a motion of an image included in input image data and creates an image in an intermediate state will be described. FIG. 76A is a diagram showing a connection relationship between a peripheral driver circuit including a source driver and a gate driver for displaying an image in a display region and a control circuit which controls the peripheral driver circuit. FIG. 76B is a diagram showing an example of a detailed circuit configuration of the control circuit. FIG. 76C is a diagram showing an example of a detailed circuit configuration of the image processing circuit included in the control circuit. FIG. 76D is a diagram showing another example of the detailed circuit configuration of the image processing circuit included in the control circuit.

As in FIG. 76A, the device in this embodiment may include a control circuit 7611, a source driver 7612, a gate driver 7613, and a display region 7614.

Note that the control circuit 7611, the source driver 7612, and the gate driver 7613 may be formed over the same substrate as the substrate where the display region 7614 is formed.

Note that part of the control circuit 7611, the source driver 7612, and the gate driver 7613 is formed over the same substrate where the display region 7614 is formed,
Other circuits may be formed over a substrate different from the substrate over which the display region 7614 is formed. For example, the source driver 7612 and the gate driver 7613 may be formed over the same substrate as the substrate where the display region 7614 is formed, and the control circuit 7611 may be formed as an external IC on a different substrate. Similarly, the gate driver 7613 may be formed over the same substrate as the substrate over which the display region 7614 is formed, and the other circuits may be formed as external ICs on different substrates. Similarly, source driver 7612
Part of the gate driver 7613 and the control circuit 7611 may be formed over the same substrate as the substrate over which the display region 7614 is formed, and the other circuits may be formed over different substrates as external ICs.

The control circuit 7611 receives the external image signal 7600, the horizontal synchronizing signal 7601, and the vertical synchronizing signal 7602, and receives the image signal 7603, the source start pulse 7604, the source clock 7605, the gate start pulse 7606, and the gate. Clock 7607,
May be output.

The source driver 7612 may have a structure in which the image signal 7603, the source start pulse 7604, and the source clock 7605 are input and a voltage or current according to the image signal 7603 is output to the display region 7614.

The gate driver 7613 uses the gate start pulse 7606 and the gate clock 7607.
May be input, and a signal that specifies the timing of writing the signal output from the source driver 7612 to the display region 7614 may be output.

When the frequency of the external image signal 7600 and the frequency of the image signal 7603 are different, the signal for controlling the timing for driving the source driver 7612 and the gate driver 7613 is also different from the input horizontal synchronization signal 7601 and vertical synchronization signal 7602. Will have different frequencies. Therefore, in addition to processing the image signal 7603, it is also necessary to process a signal for controlling the timing for driving the source driver 7612 and the gate driver 7613. The control circuit 7611 may be a circuit having a function therefor. For example, when the frequency of the image signal 7603 is double the frequency of the external image signal 7600, the control circuit 7611 interpolates the image signal included in the external image signal 7600 to generate the image signal 7603 of double frequency. In addition, the signal for controlling the timing is also controlled to have the doubled frequency.

Further, the control circuit 7611 may include an image processing circuit 7615 and a timing generation circuit 7616, as shown in FIG.

The image processing circuit 7615 may have a structure in which the external image signal 7600 and the frequency control signal 7608 are input and the image signal 7603 is output.

The horizontal synchronization signal 7601 and the vertical synchronization signal 7602 are input to the timing generation circuit 7616, and the source start pulse 7604, the source clock 7605, the gate start pulse 7606, the gate clock 7607, the frequency control signal 7608, May be output. It should be noted that the timing generation circuit 7616 uses the frequency control signal 760.
It may include a memory, a register, or the like that holds data for designating the state of 8. Further, the timing generation circuit 7616 may have a configuration in which a signal designating the state of the frequency control signal 7608 is input from the outside.

As illustrated in FIG. 76C, the image processing circuit 7615 includes a motion detection circuit 7620, a first memory 7621, a second memory 7622, a third memory 7623, and a luminance control circuit 762.
3 and the high-speed processing circuit 7625 may be included.

The motion detection circuit 7620 may be configured to input a plurality of image data, detect a motion of the image, and output image data in an intermediate state of the plurality of image data.

An external video signal 7600 is input to the first memory 7621, and the external video signal 7600 is input.
May be held for a certain period, and the external video signal 7600 may be output to the motion detection circuit 7620 and the second memory 7622.

Image data output from the first memory 7621 is input to the second memory 7622,
The image data may be output to the motion detection circuit 7620 and the high speed processing circuit 7625 while being held for a certain period of time.

The image data output from the motion detection circuit 7620 is input to the third memory 7623,
The image data may be output to the brightness control circuit 7624 while being held for a certain period of time.

The high-speed processing circuit 7625 receives the image data output from the second memory 7622, the image data output from the luminance control circuit 7624, and the frequency control signal 7608, and uses the image data as an image signal 7603. It may be configured to output.

When the frequency of the external image signal 7600 and the frequency of the image signal 7603 are different, the image signal included in the external image signal 7600 may be interpolated by the image processing circuit 7615 to generate the image signal 7603. The input external image signal 7600 is temporarily stored in the first memory 7
621 is held. At that time, the second memory 7622 holds the image data input in the immediately preceding frame. The motion detection circuit 7620 appropriately reads the image data held in the first memory 7621 and the second memory 7622, detects a motion vector from the difference between the image data of both, and further generates intermediate-state image data. May be. The generated intermediate-state image data is held by the third memory 7623.

When the motion detection circuit 7620 is generating intermediate state image data, the high speed processing circuit 762
5 outputs the image data held in the second memory 7622 as an image signal 7603. After that, the image data held in the third memory 7623 is transferred to the brightness control circuit 7624.
To output as an image signal 7603. At this time, the second memory 7622 and the third memory 7622
The frequency at which the memory 7623 is updated is the same as the frequency of the external image signal 7600, but the frequency of the image signal 7603 output through the high-speed processing circuit 7625 is the external image signal 760.
It may be different from the frequency of zero. Specifically, for example, the frequency of the image signal 7603 is 1.5 times, 2 times, or 3 times the frequency of the external image signal 7600. However, the frequency is not limited to this, and various frequencies can be used. Note that the frequency of the image signal 7603 may be designated by the frequency control signal 7608.

The structure of the image processing circuit 7615 illustrated in FIG. 76D is obtained by adding a fourth memory 7626 to the structure of the image processing circuit 7615 illustrated in FIG. As described above, in addition to the image data output from the first memory 7621 and the image data output from the second memory 7622, the image data output from the fourth memory 7626 also includes the motion detection circuit 7620.
By outputting to, it becomes possible to accurately detect the movement of the image.

If the input image data already contains a motion vector due to data compression or the like, for example, MPEG (Moving Picture Expert Gr) is used.
If the image data is based on the standard (up), an intermediate state image may be generated as an interpolation image using this. At this time, the part included in the motion detection circuit 7620 that generates the motion vector is not necessary. Further, since the encoding and decoding processes relating to the image signal 7623 are also simplified, the power consumption can be reduced.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the contents (may be part) described in each drawing of this embodiment are applied, combined, or replaced with the contents (may be part) described in each drawing of another embodiment. Can be done freely. Further, in each of the drawings of this embodiment, more drawings can be formed by combining each part with a part of another embodiment.

Note that this embodiment is an example in which the content (may be part) described in another embodiment is embodied, an example in which it is slightly modified, an example in which part is changed, and improved. An example of the case,
An example of a case described in detail, an example of application, an example of a related part, and the like are shown. Therefore, the contents described in other embodiments can be freely applied to, combined with, or replaced with this embodiment.

(Embodiment 11)
In this embodiment mode, a structure and a manufacturing method of a transistor will be described.

48A and 48B are diagrams illustrating an example of a structure of a transistor included in the display device of the present invention and a manufacturing method thereof. FIG. 48A illustrates an example of a structure of a transistor included in the display device of the present invention. 48B to 48G are diagrams illustrating an example of a method for manufacturing a transistor included in the display device of the present invention.

Note that the structure and manufacturing method of the transistor included in the display device of the present invention are not limited to those shown in FIGS. 48A and 48B, and various structures and manufacturing methods can be used.

First, an example of a structure of a transistor included in the display device of the present invention is described with reference to FIG. FIG. 48A is a cross-sectional view of a transistor having a plurality of different structures. Here, in FIG. 48A, a plurality of transistors each having a different structure are arranged side by side, but this is for explaining the structure of the transistor included in the display device of the present invention. 48A need not be juxtaposed as shown in FIG. 48A, but can be made separately as needed.

Next, each layer included in the transistor included in the display device according to the present invention will be described.

As the substrate 4011, a glass substrate of barium borosilicate glass, aluminoborosilicate glass, or the like, a quartz substrate, a ceramic substrate, a metal substrate containing stainless steel, or the like can be used.
Besides, polyethylene terephthalate (PET), polyethylene naphthalate (PEN)
It is also possible to use a substrate made of a flexible synthetic resin such as plastic or acrylic represented by Polyethersulfone (PES). By using a flexible substrate, a display device that can be bent can be manufactured.

The insulating film 4012 functions as a base film. This base film is provided in order to prevent an alkali metal such as Na or an alkaline earth metal from the substrate 4011 from adversely affecting the characteristics of the semiconductor element. The insulating film 4012 is an insulating film containing oxygen or nitrogen such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x>y), or silicon nitride oxide (SiNxOy) (x>y). Can be provided in a single layer structure or a laminated structure thereof.
For example, when the insulating film 4012 has a two-layer structure, a silicon nitride oxide film may be provided as the first insulating film and a silicon oxynitride film may be provided as the second insulating film. In the case where the insulating film 4012 has a three-layer structure, a silicon oxynitride film is provided as the first insulating film, a silicon nitride oxide film is provided as the second insulating film, and oxynitride is provided as the third insulating film. It is preferable to provide a silicon film.

The semiconductor layers 4013, 4014, and 4015 can be formed using an amorphous semiconductor or a semi-amorphous semiconductor (SAS). Alternatively, a polycrystalline semiconductor layer may be used. SAS has an intermediate structure between amorphous and crystalline structures (including single crystals and polycrystals),
It is a semiconductor having a free energy stable third state, and includes a crystalline region having short-range order and lattice distortion. At least in some regions of the film, 0.5 to 20
The crystal region of nm can be observed, and when the main component is silicon, the Raman spectrum is shifted to the lower wave number side than 520 cm ⁻¹ . In X-ray diffraction, diffraction peaks of (111) and (220) which are considered to be derived from a silicon crystal lattice are observed. At least 1 atomic% or more of hydrogen or halogen is contained as a compensator for dangling bonds. The SAS is formed by glow discharge decomposition (plasma CVD) of a material gas. As the material gas, SiH ₄ and other materials such as Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , and SiC
It is possible to use l ₄ , SiF _4, or the like. Alternatively, GeF ₄ may be mixed. This material gas may be diluted with H ₂ or H ₂ and one or more kinds of rare gas elements selected from He, Ar, Kr, and Ne. The dilution rate is in the range of 2 to 1000 times. The pressure is approximately 0.
Range of 1Pa-133Pa, power supply frequency 1MHz-120MHz, preferably 13MH
z-60 MHz. The substrate heating temperature may be 300° C. or lower. As an impurity element in the film, oxygen,
Impurities of atmospheric components such as nitrogen and carbon are preferably 1×10 ²⁰ cm ⁻¹ or less,
In particular, the oxygen concentration is 5×10 ¹⁹ /cm ³ or less, preferably 1×10 ¹⁹ /cm ³ or less. Here, an amorphous semiconductor layer is formed using a material containing silicon (Si) as a main component (for example, SixGe1-x) by using a known means (a sputtering method, an LPCVD method, a plasma CVD method, or the like). The crystalline semiconductor layer is crystallized by a known crystallization method such as a laser crystallization method, a thermal crystallization method using an RTA or a furnace annealing furnace, and a thermal crystallization method using a metal element that promotes crystallization.

The insulating film 4016 is formed of silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (Si).
The insulating film may have a single-layer structure of an insulating film containing oxygen or nitrogen such as OxNy) (x>y) or silicon nitride oxide (SiNxOy) (x>y), or a stacked structure thereof.

The gate electrode 4017 can have a single-layer conductive film or a stacked-layer structure of two-layer or three-layer conductive films. A known conductive film can be used as a material for the gate electrode 4017. For example, tantalum (Ta), titanium (Ti), molybdenum (Mo), tungsten (
W), chromium (Cr), silicon (Si), and other simple films of elements, nitride films of the above elements (typically tantalum nitride film, tungsten nitride film, titanium nitride film), or combinations of the above elements Alloy film (typically Mo-W alloy, Mo-Ta alloy), or
A silicide film of the above element (typically, a tungsten silicide film or a titanium silicide film)
Etc. can be used. Note that the single film, the nitride film, the alloy film, the silicide film, and the like described above may be used as a single layer or stacked layers.

The insulating film 4018 is formed by known means (such as a sputtering method or a plasma CVD method) on silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x>y), and silicon nitride oxide (SiNxOy) ( x>y) or other insulating film containing oxygen or nitrogen, a film containing carbon such as DLC (diamond-like carbon), or a single-layer structure, or a laminated structure thereof.

The insulating film 4019 is formed of siloxane resin, silicon oxide (SiOx), silicon nitride (Si).
Nx), silicon oxynitride (SiOxNy) (x>y), silicon oxynitride (SiNxOy) (x
>y) or other insulating film containing oxygen or nitrogen, a film containing carbon such as DLC (diamond-like carbon), or an organic material such as epoxy, polyimide, polyamide, polyvinylphenol, benzocyclobutene, or acrylic. Can be provided in a single layer or a laminated structure of. Note that the siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeletal structure with a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (eg, an alkyl group or an aryl group) is used. A fluoro group can also be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as the substituent. Note that in the display device which can be applied to the present invention, the insulating film 4019 can be directly provided so as to cover the gate electrode 4017 without providing the insulating film 4018.

The conductive film 4023 is a single film of an element such as Al, Ni, W, Mo, Ti, Pt, Cu, Ta, Au, and Mn, a nitride film of the above element, or an alloy film combining the above elements, or Alternatively, a silicide film of any of the above elements can be used. For example, as an alloy containing a plurality of the elements, an Al alloy containing C and Ti, an Al alloy containing Ni, C and N
An Al alloy containing i, an Al alloy containing C and Mn, or the like can be used. Also,
In the case of providing a laminated structure, a structure in which Al is sandwiched by Mo, Ti, or the like can be used.
By doing so, the resistance of Al to heat and chemical reactions can be improved.

Next, characteristics of each structure will be described with reference to a cross-sectional view of a transistor having a plurality of different structures illustrated in FIG.

The transistor 4001 is a single-drain transistor and can be manufactured by a simple method; therefore, it has advantages of low manufacturing cost and high yield. Here, the semiconductor layer 4
013 and 4015 have different impurity concentrations, and the semiconductor layer 4013 functions as a channel region and the semiconductor layer 4015 functions as a source region and a drain region. By controlling the amount of impurities in this manner, the resistivity of the semiconductor layer can be controlled. Further, the electrical connection state between the semiconductor layer and the conductive film 4023 can be close to ohmic connection. In addition,
As a method of separately forming semiconductor layers having different amounts of impurities, a method of doping impurities into the semiconductor layers with the gate electrode 4017 as a mask can be used.

The transistor 4002 is a transistor in which the gate electrode 4017 has a taper angle of a certain value or more and can be manufactured by a simple method; therefore, there is an advantage that manufacturing cost is low and manufacturing yield is high. The semiconductor layers 4013, 4014, and 4015 have different impurity concentrations, the semiconductor layer 4013 is a channel region, and the semiconductor layer 4014 is a low concentration drain (Lightl).
The y-doped drain (LDD) region and the semiconductor layer 4015 are used as a source region and a drain region. By controlling the amount of impurities in this manner, the resistivity of the semiconductor layer can be controlled. Further, the electrical connection state between the semiconductor layer and the conductive film 4023 can be close to ohmic connection. In addition, since the transistor has the LDD region, a high electric field is unlikely to be applied inside the transistor, and deterioration of the element due to hot carriers can be suppressed. As a method of separately forming semiconductor layers having different amounts of impurities, a method of doping impurities into the semiconductor layers with the gate electrode 4017 as a mask can be used. In the transistor 4002, since the gate electrode 4017 has a taper angle, the concentration of impurities which are doped into the semiconductor layer through the gate electrode 4017 can have a gradient and an LDD region can be easily formed. can do.

The gate electrode of the transistor 4003 is formed of at least two layers, and the gate electrode 4 of the lower layer is included.
017a is a transistor having a shape longer than the gate electrode 4017b in the upper layer. In this specification, the shapes of the upper-layer gate electrode and the lower-layer gate electrode are referred to as a hat shape.
Since the gate electrode has a hat shape, LDD can be performed without adding a photomask.
Regions can be formed. Note that a structure in which an LDD region overlaps with a gate electrode like the transistor 4003 is particularly referred to as a GOLD structure (Gate Overlapped L).
DD). The following method may be used as a method of forming the gate electrode into a hat shape.

First, when the gate electrode is patterned, the lower-layer gate electrode and the upper-layer gate electrode are etched by dry etching to form a side surface with an inclination (taper). Subsequently, anisotropic etching is performed so that the upper-layer gate electrode is inclined so as to be nearly vertical.
As a result, a gate electrode having a hat-shaped cross section is formed. After that, by doping the impurity element twice, a semiconductor layer 4013 used as a channel region, a semiconductor layer 4014 used as an LDD region, and a semiconductor layer 40 used as a source electrode and a drain electrode.
15 is formed.

The LDD region overlapping with the gate electrode will be referred to as a Lov region, and the LDD region not overlapping with the gate electrode will be referred to as a Loff region. Here, the Loff region has a high effect of suppressing the off current value, but has a low effect of relaxing the electric field near the drain to prevent the deterioration of the on current value due to hot carriers. On the other hand, the Lov region relaxes the electric field near the drain and is effective in preventing the deterioration of the on-current value, but has a low effect of suppressing the off-current value. Therefore, it is preferable to manufacture a transistor having a structure depending on required characteristics for each of various circuits. For example, when a display device that can be applied to the present invention is used as a display device, it is preferable to use a transistor having a Loff region as the pixel transistor in order to suppress the off-state current value. On the other hand, as the transistor in the peripheral circuit, it is preferable to use a transistor having a Lov region in order to reduce the electric field near the drain and prevent deterioration of the on-state current value.

The transistor 4004 is in contact with the side surface of the gate electrode 4017 and has a side wall 4021.
Is a transistor having. By including the side wall 4021, a region overlapping with the side wall 4021 can be an LDD region.

The transistor 4005 is LDDed by doping the semiconductor layer with a mask.
It is a transistor in which a (Loff) region is formed. By doing so, the LDD region can be reliably formed, and the off-state current value of the transistor can be reduced.

The transistor 4006 is LDDed by doping the semiconductor layer with a mask.
It is a transistor in which a (Lov) region is formed. By doing so, the LDD region can be reliably formed, the electric field in the vicinity of the drain of the transistor can be relaxed, and deterioration of the on-current value can be reduced.

Next, with reference to FIGS. 48B to 48G, an example of a method for manufacturing a transistor included in the display device of the present invention will be described.

Note that the structure and manufacturing method of the transistor included in the display device of the present invention are not limited to those shown in FIGS. 48A and 48B, and various structures and manufacturing methods can be used.

In this embodiment mode, the substrate 4011, the insulating film 4012, and the semiconductor layers 4013 and 4014.
, 4015, the insulating film 4016, the insulating film 4018, and the insulating film 4019 can be oxidized or nitrided by performing oxidation or nitridation treatment using plasma treatment. As described above, the surface of the semiconductor layer or the insulating film is modified by oxidizing or nitriding the semiconductor layer or the insulating film by using plasma treatment, and compared with an insulating film formed by a CVD method or a sputtering method. A more precise insulating film can be formed. Therefore, it becomes possible to suppress defects such as pinholes and improve the characteristics and the like of the display device.

First, the surface of the substrate 4011 is washed with hydrofluoric acid (HF), alkali, or pure water. The substrate 4011 is a glass substrate such as barium borosilicate glass or aluminoborosilicate glass,
A quartz substrate, a ceramic substrate, a metal substrate containing stainless steel, or the like can be used. In addition, a substrate made of a plastic typified by polyethylene terephthalate (PET), polyethylene naphthalate (PEN) or polyethylene ether sulfone (PES) or a flexible synthetic resin such as acryl is used. It is also possible to use. Note that a glass substrate is used as the substrate 4011 here.

Here, the surface of the substrate 4011 is oxidized or nitrided by performing plasma treatment,
An oxide film or a nitride film may be formed on the surface of the (FIG. 48(B)). An insulating film such as an oxide film or a nitride film formed by performing plasma treatment on the surface is also referred to as a plasma-treated insulating film below. Note that in FIG. 48B, the insulating film 4031 is a plasma treatment insulating film. Generally, when a semiconductor element such as a thin film transistor is provided on a substrate such as glass or plastic, an impurity element such as an alkali metal such as Na or an alkaline earth metal contained in the glass or plastic is mixed into the semiconductor element. As a result, the characteristics of the semiconductor element may be affected. However, by nitriding the surface of the substrate made of glass, plastic, or the like, it is possible to prevent the impurity element such as Na contained in the substrate, such as an alkali metal or an alkaline earth metal, from being mixed into the semiconductor element.

In addition, when the surface is oxidized by the plasma treatment, under an oxygen atmosphere (for example, oxygen (O ₂
) And a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, or an atmosphere of oxygen and hydrogen (H ₂ ) and a rare gas, or an atmosphere of dinitrogen monoxide and a rare gas. )
Plasma treatment is performed. On the other hand, in the case of nitriding the semiconductor layer by plasma treatment, in a nitrogen atmosphere (for example, in a nitrogen (N ₂ ) and rare gas (including at least one of He, Ne, Ar, Kr, and Xe)) atmosphere, or Plasma treatment is performed in an atmosphere of nitrogen and hydrogen and a rare gas or in an atmosphere of NH ₃ and a rare gas). As the rare gas, for example, a gas such as Ar or a mixture of Ar and Kr can be used. Therefore, the plasma treatment insulating film contains the rare gas (including at least one of He, Ne, Ar, Kr, and Xe) used for the plasma treatment. For example, when Ar is used, the plasma-treated insulating film contains Ar.

In the plasma treatment, the electron density is 1×10 ¹¹ cm ⁻³ in the atmosphere of the above gas.
Or more and 1×10 ¹³ cm ⁻³ or less, and the plasma electron temperature is 0.5 ev or more and 1.5 eV or more.
The following treatment is preferable. This is because the electron density of plasma is high and the electron temperature near the object to be processed is low, so that damage to the object to be processed due to the plasma can be prevented. In addition, since the electron density of plasma is as high as 1×10 ¹¹ cm ⁻³ or more,
An oxide or nitride film formed by oxidizing or nitriding an irradiation object by using plasma treatment is superior in uniformity of film thickness as compared with a film formed by a CVD method, a sputtering method, or the like,
In addition, a dense film can be formed. Alternatively, since the electron temperature of plasma is as low as 1 eV or less, the oxidation or nitriding treatment can be performed at a lower temperature than the conventional plasma treatment or thermal oxidation method. For example, even if the plasma treatment is performed at a temperature lower than the strain point temperature of the glass substrate by 100° C. or more, the oxidation or nitriding treatment can be sufficiently performed. Note that a high frequency wave such as a microwave (2.45 GHz) can be used as a frequency for forming plasma. Unless otherwise specified below, plasma treatment is performed under the above conditions.

Note that FIG. 48B illustrates the case where the plasma treatment insulating film is formed by performing plasma treatment on the surface of the substrate 4011; however, in this embodiment, the plasma treatment insulating film is formed on the surface of the substrate 4011. Including the case of not forming.

Note that although a plasma-treated insulating film formed by performing plasma treatment on the surface of the object to be processed is not illustrated in FIGS. 48C to 48G, the substrate 40 is used in this embodiment.
The case where a plasma-treated insulating film formed by performing plasma treatment exists on the surface of the insulating film 4012, the insulating film 4012, the semiconductor layers 4013, 4014, 4015, the insulating film 4016, the insulating film 4018, or the insulating film 4019 is also included.

Next, a known means (sputtering method, LPCVD method, plasma CVD method, etc.) is formed on the substrate 4011.
An insulating film 4012 is formed by using (FIG. 48C). As the insulating film 4012, silicon oxide (SiOx) or silicon oxynitride (SiOxNy) (x>y) can be used.

Here, a plasma treatment insulating film may be formed on the surface of the insulating film 4012 by performing plasma treatment on the surface of the insulating film 4012 and oxidizing or nitriding the insulating film 4012. By oxidizing the surface of the insulating film 4012, the surface of the insulating film 4012 can be modified and a dense film with few defects such as pinholes can be obtained. Further, by oxidizing the surface of the insulating film 4012, a plasma-treated insulating film having a low N atom content can be formed. Therefore, when a semiconductor layer is provided for the plasma-treated insulating film, the plasma-treated insulating film and the semiconductor are not formed. The layer interface characteristics are improved. Further, the plasma-treated insulating film is a rare gas (He, Ne, Ar,
(Including at least one of Kr and Xe). The plasma treatment can be similarly performed under the above-mentioned conditions.

Next, island-shaped semiconductor layers 4013 and 4014 are formed over the insulating film 4012 (FIG. 48D).
). The island-shaped semiconductor layers 4013 and 4014 are formed of a material containing silicon (Si) as a main component over the insulating film 4012 by a known method (a sputtering method, an LPCVD method, a plasma CVD method, or the like).
For example, it can be provided by forming an amorphous semiconductor layer using, for example, SixGe1-x, etc., crystallizing the amorphous semiconductor layer, and selectively etching the semiconductor layer. In addition,
Crystallization of the amorphous semiconductor layer includes laser crystallization, thermal crystallization using RTA or furnace annealing, thermal crystallization using a metal element that promotes crystallization, or a combination of these methods. The known crystallization method can be used. Note that here, the end portions of the island-shaped semiconductor layer are provided in a shape close to a right angle (θ=85 to 100°). Alternatively, the semiconductor layer 4014 to be the low-concentration drain region may be formed by doping impurities with a mask.

Here, plasma treatment is performed on the surfaces of the semiconductor layers 4013 and 4014 to remove the semiconductor layers 4013 and 4014.
A plasma-treated insulating film may be formed on the surfaces of the semiconductor layers 4013 and 4014 by oxidizing or nitriding the surface of 4014. For example, as the semiconductor layers 4013 and 4014, Si
In the case of using, as a plasma-treated insulating film, silicon oxide (SiOx) or silicon nitride (SiN) is used.
x) is formed. Alternatively, after the semiconductor layers 4013 and 4014 are oxidized by plasma treatment, plasma treatment may be performed again to nitride the semiconductor layers 4013 and 4014. In this case, silicon oxide (SiOx) is formed in contact with the semiconductor layers 4013 and 4014, and silicon nitride oxide (SiNxOy) (x>y) is formed on the surface of the silicon oxide. Note that when the semiconductor layer is oxidized by plasma treatment, oxygen atmosphere (for example, oxygen (O ₂ ) and a rare gas (He, Ne, A) is used.
Plasma treatment is performed in an atmosphere containing at least one of r, Kr, and Xe) or in an atmosphere of oxygen and hydrogen (H ₂ ) and a rare gas or in an atmosphere of dinitrogen monoxide and a rare gas). On the other hand, when the semiconductor layer is nitrided by plasma treatment, in a nitrogen atmosphere (for example, in a nitrogen (N ₂ ) and rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, or Plasma treatment is performed under nitrogen, hydrogen, and a rare gas atmosphere or NH3 and a rare gas atmosphere). As the rare gas, for example, Ar can be used. Alternatively, a gas in which Ar and Kr are mixed may be used. Therefore, the plasma-treated insulating film is formed of the rare gas (He, Ne) used for the plasma treatment.
, Ar, Kr, and Xe). For example, when Ar is used, the plasma-treated insulating film contains Ar.

Next, the insulating film 4016 is formed (FIG. 48E). The insulating film 4016 is formed by using a known method (a sputtering method, an LPCVD method, a plasma CVD method, or the like), silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x>y), or oxynitride. Silicon (SiNx
The insulating film may have a single-layer structure of an insulating film containing oxygen or nitrogen such as Oy) (x>y) or a laminated structure of these. Note that when a plasma treatment insulating film is formed on the surfaces of the semiconductor layers 4013 and 4014 by plasma-treating the surfaces of the semiconductor layers 4013 and 4014,
A plasma treatment insulating film can also be used as the insulating film 4016.

Here, a plasma treatment insulating film may be formed on the surface of the insulating film 4016 by performing plasma treatment on the surface of the insulating film 4016 and oxidizing or nitriding the surface of the insulating film 4016.
Note that the plasma-treated insulating film is a rare gas (He, Ne, Ar, Kr, or
(Including at least one of Xe). Further, the plasma treatment can be similarly performed under the above-mentioned conditions.

Alternatively, the insulating film 4016 may be once oxidized by performing plasma treatment in an oxygen atmosphere and then nitrided by performing plasma treatment again in a nitrogen atmosphere. In this manner, by performing plasma treatment on the insulating film 4016 and oxidizing or nitriding the surface of the insulating film 4016, the surface of the insulating film 4016 can be modified and a dense film can be formed. The insulating film obtained by performing the plasma treatment is denser and has fewer defects such as pinholes as compared with an insulating film formed by a CVD method or a sputtering method; therefore, the characteristics of the thin film transistor can be improved.

Next, the gate electrode 4017 is formed (FIG. 48F). The gate electrode 4017 can be formed by a known method (a sputtering method, an LPCVD method, a plasma CVD method, or the like).

In the transistor 4001, the semiconductor layer 4015 used as a source region and a drain region can be formed by performing impurity doping after forming the gate electrode 4017.

In the transistor 4002, impurity doping is performed after the gate electrode 4017 is formed, so that the semiconductor layer 4013 used as the LDD region 4014 and the semiconductor layer 4015 used as the source and drain regions can be formed.

In the transistor 4003, impurity doping is performed after the gate electrodes 4017a and 4017b are formed, so that 4014 used as an LDD region and the semiconductor layer 4013 are formed.
A semiconductor layer 4015 used as a source region and a drain region can be formed.

In the transistor 4004, a sidewall 4021 is formed on the side surface of the gate electrode 4017.
After forming the film, impurity doping is performed to thereby use 4014 as an LDD region,
A semiconductor layer 4013 and a semiconductor layer 4015 used as a source region and a drain region can be formed.

Note that the sidewall 4021 can be formed using silicon oxide (SiOx) or silicon nitride (SiNx). As a method of forming the side wall 4021 on the side surface of the gate electrode 4017, for example, after forming the gate electrode 4017, silicon oxide (SiOx) or silicon nitride (SiNx) is formed by a known method, and then anisotropically formed. Silicon oxide (
A method of etching a SiOx) or silicon nitride (SiNx) film can be used. By doing so, silicon oxide (SiOx) or silicon nitride (S) is formed only on the side surface of the gate electrode 4017.
Since the iNx) film can be left, the side wall 402 is formed on the side surface of the gate electrode 4017.
1 can be formed.

In the transistor 4005, a mask 4022 is formed so as to cover the gate electrode 4017, and then impurity doping is performed to use it as an LDD (Loff) region 40.
14 and a semiconductor layer 4013 used as a source region and a drain region.
Can be formed.

In the transistor 4006, impurity doping is performed after the gate electrode 4017 is formed, so that a semiconductor layer 4013 used as an LDD (Lov) region and a semiconductor layer 4015 used as a source region and a drain region can be formed. it can.

Next, the insulating film 4018 is formed (FIG. 48G). The insulating film 4018 is formed of silicon oxide (SiOx) or silicon nitride (SiNx) by a known method (such as a sputtering method or a plasma CVD method).
, Silicon oxynitride (SiOxNy) (x>y), silicon oxynitride (SiNxOy) (x>y)
A single-layer structure of an insulating film containing oxygen or nitrogen such as, a film containing carbon such as DLC (diamond-like carbon), or a laminated structure of these.

Here, a plasma treatment insulating film may be formed on the surface of the insulating film 4018 by performing plasma treatment on the surface of the insulating film 4018 and oxidizing or nitriding the surface of the insulating film 4018.
Note that the plasma-treated insulating film is a rare gas (He, Ne, Ar, Kr, or
(Including at least one of Xe). Further, the plasma treatment can be similarly performed under the above-mentioned conditions.

Next, the insulating film 4019 is formed (FIG. 48A). The insulating film 4019 is formed of silicon oxide (SiOx) or silicon nitride (SiNx) by known means (sputtering method, plasma CVD method, etc.).
, Silicon oxynitride (SiOxNy) (x>y), silicon oxynitride (SiNxOy) (x>y)
In addition to an insulating film containing oxygen or nitrogen such as DLC (diamond-like carbon) or a film containing carbon such as DLC (diamond-like carbon), epoxy, polyimide, polyamide, polyvinylphenol, benzocyclobutene, acrylic, etc. can be used. A single layer structure of an organic material or a siloxane resin, or a laminated structure of these can be provided. Note that the siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeletal structure with a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (eg, an alkyl group or an aryl group) is used. A fluoro group can also be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as the substituent. The plasma-treated insulating film contains a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) used for plasma treatment. For example, when Ar is used, plasma-treated insulating film is used. Ar is contained in the film.

When an organic material such as polyimide, polyamide, polyvinylphenol, benzocyclobutene, or acrylic, or a siloxane resin is used as the insulating film 4019, the surface of the insulating film 4019 is oxidized or nitrided by plasma treatment, so that the insulating film The surface of can be modified. By modifying the surface, the strength of the insulating film 4019 is improved, and it becomes possible to reduce the physical damage such as the generation of cracks at the time of forming openings and the film loss at the time of etching. Further, when the surface of the insulating film 4019 is modified, adhesion with the conductive film is improved when the conductive film 4023 is formed over the insulating film 4019. For example, when nitriding is performed using plasma treatment using a siloxane resin as the insulating film 4019, the surface of the siloxane resin is nitrided, whereby a plasma-treated insulating film containing nitrogen or a rare gas is formed, and the physical strength is increased. improves.

Next, the insulating film 4 is formed to form the conductive film 4023 which is electrically connected to the semiconductor layer 4015.
Contact holes are formed in 019, the insulating film 4018, and the insulating film 4016. The contact hole may have a tapered shape, and the conductive film 4 having such a shape can be used.
The coverage of 023 can be improved.

FIG. 49 shows a cross-sectional structure of a bottom-gate transistor and a cross-sectional structure of a capacitor.

A first insulating film (insulating film 4102) is formed over the entire surface of the substrate 4101. The first insulating film has a function of preventing impurities from the substrate side from affecting the semiconductor layer and changing the characteristics of the transistor. That is, the first insulating film has a function as a base film. Therefore, a highly reliable transistor can be manufactured. Note that as the first insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

A first conductive layer (a conductive layer 4103 and a conductive layer 4104) is formed over the first insulating film. The conductive layer 4103 includes a portion functioning as a gate electrode of the transistor 4120.
The conductive layer 4104 includes a portion functioning as a first electrode of the capacitor 4121. The first conductive layer includes Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, P.
It is possible to use t, Si, Zn, Fe, Ba, Ge or the like, or an alloy thereof. Alternatively, a stack of these elements (including alloys) can be used.

A second insulating film (insulating film 4122) is formed so as to cover at least the first conductive layer. The second insulating film has a function as a gate insulating film. Note that as the second insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is preferable to use a silicon oxide film as the second insulating film in a portion in contact with the semiconductor layer. This is because the trap level at the interface between the semiconductor layer and the second insulating film is reduced.

In addition, when the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as a portion of the second insulating film in contact with Mo. This is because the silicon oxide film does not oxidize Mo.

A semiconductor layer is formed by a photolithography method, an inkjet method, a printing method, or the like on part of a portion of the second insulating film which is formed to overlap with the first conductive layer. Then, a part of the semiconductor layer extends to a part of the second insulating film which is not formed so as to overlap with the first conductive layer. The semiconductor layer is a channel formation region (channel formation region 4110
), an LDD region (LDD region 4108, LDD region 4109), and an impurity region (impurity region 4105, impurity region 4106, impurity region 4107). Note that the channel formation region 4110 functions as a channel formation region of the transistor 4120. The LDD region 4108 and the LDD region 4109 function as the LDD region of the transistor 4120. The LDD region 4108 and the LDD region 4109 are not always necessary. The impurity region 4105 includes a portion functioning as one of a source region and a drain region of the transistor 4120. The impurity region 4106 includes a portion functioning as the other of the source region and the drain region of the transistor 4120. The impurity region 4107 includes a portion functioning as a second electrode of the capacitor 4121.

A third insulating film (insulating film 4111) is formed on the entire surface. In a part of the third insulating film,
Contact holes are selectively formed. The insulating film 4111 has a function as an interlayer film. As the third insulating film, an inorganic material (silicon oxide, silicon nitride, silicon oxynitride, etc.) or a low dielectric constant organic compound material (photosensitive or non-photosensitive organic resin material)
Etc. can be used. Alternatively, a material containing siloxane can be used. Note that siloxane is a material whose skeletal structure is formed by a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aryl group)
Is used. Alternatively, a fluoro group may be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as the substituent.

A second conductive layer (conductive layer 4112) is formed over the third insulating film. Conductive layer 4112
Are connected to the other of the source region and the drain region of the transistor 4120 through a contact hole formed in the third insulating film. Therefore, the conductive layer 4112 includes a portion functioning as the other of the source electrode and the drain electrode of the transistor 4120. In addition,
As the second conductive layer, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au,
Pt, Si, Zn, Fe, Ba, Ge or the like, or alloys thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

Note that various insulating films or various conductive films may be formed as a step after the second conductive layer is formed.

Next, structures of a transistor and a capacitor in the case where an amorphous silicon (a-Si:H) film is used for a semiconductor layer of the transistor will be described.

FIG. 50 shows a cross-sectional structure of a top-gate transistor and a cross-sectional structure of a capacitor.

A first insulating film (insulating film 4202) is formed over the entire surface of the substrate 4201. The first insulating film has a function of preventing impurities from the substrate side from affecting the semiconductor layer and changing the characteristics of the transistor. That is, the first insulating film has a function as a base film. Therefore, a highly reliable transistor can be manufactured. Note that as the first insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is not always necessary to form the first insulating film. In this case, the number of steps can be reduced. The manufacturing cost can be reduced. Since the structure can be simplified, the yield can be improved.

A first conductive layer (a conductive layer 4203, a conductive layer 4204, and a conductive layer 4205) is formed over the first insulating film.
) Has been formed. The conductive layer 4203 includes a portion functioning as one of a source electrode and a drain electrode of the transistor 4220. The conductive layer 4204 is the transistor 422.
The source electrode of 0 and the portion functioning as the other electrode of the drain electrode are included. Conductive layer 420
5 includes a portion functioning as a first electrode of the capacitor 4221. The first conductive layer is made of Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Si, Z.
n, Fe, Ba, Ge, etc., or alloys thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

A first semiconductor layer (semiconductor layer 4206 and semiconductor layer 4207) is formed over the conductive layers 4203 and 4204. The semiconductor layer 4206 includes a portion functioning as one electrode of the source region and the drain region. The semiconductor layer 4207 includes a portion functioning as the other electrode of the source region and the drain region. Note that silicon or the like containing phosphorus or the like can be used for the first semiconductor layer.

A second semiconductor layer (semiconductor layer 4208) is formed between the conductive layers 4203 and 4204 and over the first insulating film. Then, part of the semiconductor layer 4208 extends over the conductive layer 4203 and the conductive layer 4204. The semiconductor layer 4208 includes a portion functioning as a channel region of the transistor 4220. Note that as the second semiconductor layer,
A non-crystalline semiconductor layer such as amorphous silicon (a-Si:H) or a semiconductor layer such as a microcrystalline semiconductor (μ-Si:H) can be used.

The second insulating film (insulating film 4) is formed so as to cover at least the semiconductor layer 4208 and the conductive layer 4205.
209 and an insulating film 4210) are formed. The second insulating film has a function as a gate insulating film. Note that as the second insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is preferable to use a silicon oxide film as the second insulating film in a portion in contact with the second semiconductor layer. This is because the trap level at the interface between the second semiconductor layer and the second insulating film is reduced.

In addition, when the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as a portion of the second insulating film in contact with Mo. This is because the silicon oxide film does not oxidize Mo.

A second conductive layer (a conductive layer 4211 and a conductive layer 4212) is formed over the second insulating film. The conductive layer 4211 includes a portion functioning as a gate electrode of the transistor 4220.
The conductive layer 4212 functions as a second electrode of the capacitor 4221 or a wiring. The second conductive layer may be Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, A.
u, Pt, Si, Zn, Fe, Ba, Ge or the like, or alloys thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

Note that various insulating films or various conductive films may be formed as a step after the second conductive layer is formed.

51A and 51B show cross-sectional structures of an inverted staggered (bottom gate) transistor and a capacitor. In particular, the transistor shown in FIG. 51 has a structure called a channel etch type.

A first insulating film (insulating film 4302) is formed over the entire surface of the substrate 4301. The first insulating film has a function of preventing impurities from the substrate side from affecting the semiconductor layer and changing the characteristics of the transistor. That is, the first insulating film has a function as a base film. Therefore, a highly reliable transistor can be manufactured. Note that as the first insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is not always necessary to form the first insulating film. In this case, the number of steps can be reduced. The manufacturing cost can be reduced. Since the structure can be simplified, the yield can be improved.

A first conductive layer (a conductive layer 4303 and a conductive layer 4304) is formed over the first insulating film. The conductive layer 4303 includes a portion functioning as a gate electrode of the transistor 4320.
The conductive layer 4304 includes a portion functioning as a first electrode of the capacitor 4321. As the first conductive layer, Ti, Mo, TB, Cr, W, Bl, Nd, Cu, Bg, Bu, P is used.
t, NA-Si, Zn, Fe, Ba, Ge, or the like, or an alloy thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

A second insulating film (insulating film 4302) is formed so as to cover at least the first conductive layer. The second insulating film has a function as a gate insulating film. Note that as the second insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is preferable to use a silicon oxide film as the second insulating film in a portion in contact with the semiconductor layer. This is because the trap level at the interface between the semiconductor layer and the second insulating film is reduced.

In addition, when the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as a portion of the second insulating film in contact with Mo. This is because the silicon oxide film does not oxidize Mo.

The first semiconductor layer (semiconductor layer 43) is formed by a photolithography method, an inkjet method, a printing method, or the like on a part of a portion of the second insulating film which is formed so as to overlap with the first conductive layer.
06) is formed. Then, part of the semiconductor layer 4306 is extended to a part of the second insulating film which is not formed so as to overlap with the first conductive layer. The semiconductor layer 4306 is
A portion functioning as a channel region of the transistor 4320 is included. Note that the semiconductor layer 430
As 6, a non-crystalline semiconductor layer such as amorphous silicon (A-Si:H) or a semiconductor layer such as a microcrystalline semiconductor (μ-Si:H) can be used.

The second semiconductor layer (the semiconductor layer 4307 and the semiconductor layer 4308) is partly provided over the first semiconductor layer.
Are formed. The semiconductor layer 4307 includes a portion functioning as one electrode of the source region and the drain region. The semiconductor layer 4308 includes a portion functioning as the other electrode of the source region and the drain region. Note that silicon or the like containing phosphorus or the like can be used for the second conductor layer.

A second conductive layer (a conductive layer 4309 and a conductive layer 431) is formed over the second semiconductor layer and the second insulating film.
0 and the conductive layer 4311) are formed. The conductive layer 4309 includes a portion functioning as one of a source electrode and a drain electrode of the transistor 4320. The conductive layer 4310 includes a portion functioning as the other of the source and the drain electrode of the transistor 4320. Conductive layer 431
2 includes a portion functioning as a second electrode of the capacitor 4321. The second conductive layer is made of Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Si, Z.
n, Fe, Ba, Ge, etc., or alloys thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

Note that various insulating films or various conductive films may be formed as a step after the second conductive layer is formed.

Here, an example of a process which is characteristic of a channel-etch type transistor will be described. The same mask can be used to form the first semiconductor layer and the second semiconductor layer. In particular,
The first semiconductor layer and the second semiconductor layer are continuously formed. Then, the first semiconductor layer and the second semiconductor layer are formed using the same mask.

Another example of the process characterized by the channel-etch type transistor will be described. The channel region of the transistor can be formed without using a new mask. In particular,
After the second conductive layer is formed, part of the second semiconductor layer is removed using the second conductive layer as a mask. Alternatively, part of the second semiconductor layer is removed using the same mask as the second conductive layer. Then, the first semiconductor layer formed below the removed second semiconductor layer serves as a channel region of the transistor.

52A and 52B show cross-sectional structures of an inverted staggered (bottom gate) transistor and a capacitor. In particular, the transistor illustrated in FIG. 52 has a structure called a channel protection type (channel stop type).

A first insulating film (insulating film 4402) is formed over the entire surface of the substrate 4401. The first insulating film has a function of preventing impurities from the substrate side from affecting the semiconductor layer and changing the characteristics of the transistor. That is, the first insulating film has a function as a base film. Therefore, a highly reliable transistor can be manufactured. Note that as the first insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is not always necessary to form the first insulating film. In this case, the number of steps can be reduced. The manufacturing cost can be reduced. Since the structure can be simplified, the yield can be improved.

A first conductive layer (a conductive layer 4403 and a conductive layer 4404) is formed over the first insulating film. The conductive layer 4403 includes a portion functioning as a gate electrode of the transistor 4420.
The conductive layer 4404 includes a portion functioning as a first electrode of the capacitor 4421. The first conductive layer includes Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, P.
It is possible to use t, Si, Zn, Fe, Ba, Ge or the like, or an alloy thereof. Alternatively, a stack of these elements (including alloys) can be used.

A second insulating film (insulating film 4402) is formed so as to cover at least the first conductive layer. The second insulating film has a function as a gate insulating film. Note that as the second insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

Note that it is preferable to use a silicon oxide film as the second insulating film in a portion in contact with the semiconductor layer. This is because the trap level at the interface between the semiconductor layer and the second insulating film is reduced.

In addition, when the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as a portion of the second insulating film in contact with Mo. This is because the silicon oxide film does not oxidize Mo.

The first semiconductor layer (semiconductor layer 44) is formed by a photolithography method, an inkjet method, a printing method, or the like on a part of a portion of the second insulating film which is formed so as to overlap with the first conductive layer.
06) is formed. Then, a part of the semiconductor layer 4406 is extended to a portion of the second insulating film which is not formed so as to overlap with the first conductive layer. The semiconductor layer 4406 is
A portion functioning as a channel region of the transistor 4420 is included. Note that the semiconductor layer 440
As 6, an amorphous semiconductor layer such as amorphous silicon (C—Si:H) or a semiconductor layer such as a microcrystalline semiconductor (μ-Si:H) can be used.

A third insulating film (insulating film 4412) is formed on part of the first semiconductor layer. The insulating film 4412 has a function of preventing the channel region of the transistor 4420 from being removed by etching. That is, the insulating film 4412 functions as a channel protective film (channel stop film). Note that as the third insulating film, a single layer such as a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiOxNy), or a stacked layer thereof can be used.

A second semiconductor layer (semiconductor layer 440) is formed on a part of the first semiconductor layer and a part of the third insulating film.
7 and a semiconductor layer 4408) are formed. The semiconductor layer 4407 includes a portion functioning as one electrode of the source region and the drain region. The semiconductor layer 4408 includes a portion functioning as the other electrode of the source region and the drain region. Note that silicon or the like containing phosphorus or the like can be used for the second conductor layer.

A second conductive layer (a conductive layer 4409, a conductive layer 4410, and a conductive layer 441) is formed over the second semiconductor layer.
1) is formed. The conductive layer 4409 includes a portion functioning as one of a source electrode and a drain electrode of the transistor 4420. The conductive layer 4410 includes a portion functioning as the other of the source and the drain electrode of the transistor 4420. The conductive layer 4411 is the capacitance element 44.
21 includes a portion functioning as a second electrode. In addition, as the second conductive layer, Ti, Mo
, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Si, Zn, Fe, Ba, G
e, etc., or alloys thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

Note that various insulating films or various conductive films may be formed as a step after the second conductive layer is formed.

Here, an example of a process which is characteristic of a channel protection transistor will be described. The same mask can be used to form the first semiconductor layer, the second semiconductor layer, and the second conductive layer.
At the same time, the channel region can be formed. Specifically, a first semiconductor layer is formed,
Next, a third insulating film (channel protective film, channel stop film) is formed using a mask,
Next, the second semiconductor layer and the second conductive layer are continuously formed. Then, after the second conductive layer is formed, the first semiconductor layer, the second semiconductor layer, and the second conductive layer are formed using the same mask. However, since the first semiconductor layer below the third insulating film is protected by the third insulating film, it is not removed by etching. This portion (the portion of the first semiconductor layer on which the third insulating film is formed) serves as a channel region.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the content (may be part) described in each drawing of this embodiment is applied to or combined with the content (may be part) described in the drawings of other embodiments and examples. , Or replacement can be freely performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each part with parts of another embodiment mode and examples.

Note that in this embodiment, the contents (may be part) described in the other embodiments and examples are
Example of embodying, example of slightly deforming, example of partially changing, example of improving, example of detailed description, example of application, example of related parts And so on. Therefore, the contents described in other embodiment modes and examples can be freely applied to, combined with, or replaced with this embodiment mode.

(Embodiment 12)
In the present embodiment, examples of electronic devices according to the present invention will be described.

FIG. 53 shows one mode of a display panel module in which a display panel 4501 and a circuit board 4502 are combined.

As shown in FIG. 53, the display panel 4501 includes a pixel portion 4503 and a scan line driver circuit 4504.
And a signal line driver circuit 4505. A control circuit 4506, a signal division circuit 4507, and the like are formed on the circuit board 4502, for example. The display panel 450
1 and the circuit board 4502 are connected by the connection wiring 4508. An FPC or the like can be used for the connection wiring 4508.

In the display panel 4501, a pixel portion and part of a peripheral driver circuit (a driver circuit with a low operating frequency among a plurality of driver circuits) is formed over a substrate by using transistors, and another peripheral driver circuit (a plurality of driver circuits) is formed. Of these, a driving circuit having a high operating frequency) may be formed over an IC chip and the IC chip may be mounted on the display panel 3410 by COG (Chip On Glass). Alternatively, the IC chip may be connected to the glass substrate by using TAB (Tape Auto Bonding) or a printed board. Alternatively, all the peripheral drive circuits may be formed on an IC chip and the IC chip may be mounted on the display panel by COG or the like.

Note that the pixel described in any of the above embodiments is used for the pixel portion. According to the present invention, the viewing angle can be improved. In addition, cost reduction can be achieved by using a transistor of the same conductivity type for a transistor included in the pixel portion or using an amorphous semiconductor for a semiconductor layer of the transistor.

A television receiver can be completed with such a display module. FIG. 54 shows
It is a block diagram which shows the main structures of a television receiver. The tuner 4601 receives a video signal and an audio signal. The video signal includes a video signal amplification circuit 4602, a video signal processing circuit 4603 that converts the signals output from the video signal into color signals corresponding to red, green, and blue colors, and the video signal as input specifications of the drive circuit. It is processed by the control circuit 4506 for conversion.
The control circuit 4506 outputs signals to the scanning line side and the signal line side, respectively. In the case of digital driving, a signal dividing circuit 4507 is provided on the signal line side and m input digital signals (
m may be a positive integer).

Of the signals received by the tuner 4601, an audio signal is sent to the audio signal amplifier circuit 4604, and its output is supplied to the speaker 4606 via the audio signal processing circuit 4605. The control circuit 4607 receives control information of a receiving station (reception frequency) and volume from the input unit 4608, and sends a signal to the tuner 4601 and the audio signal processing circuit 4605.

FIG. 55 shows a television receiver incorporating a display panel module of a different form from that of FIG.
Shown in A). In FIG. 55A, the display screen 4702 contained in the housing 4701 is
It is formed of a display panel module. A speaker 4703 and operation switch 4704
And the like may be appropriately provided.

FIG. 55B shows a television receiver in which only the display can be carried wirelessly.
A battery and a signal receiver are incorporated in the housing 4712, and the display portion 4713 or the speaker portion 4717 is driven by the battery. The battery can be repeatedly charged by the charger 4710. The charger 4710 can send and receive a video signal, and the video signal can be sent to the signal receiver of the display. The housing 4712 is controlled by operation keys 4716. Alternatively, the device illustrated in FIG. 55B may be a video/audio two-way communication device capable of transmitting a signal from the housing 4712 to the charger 4710 by operating the operation key 4716. Alternatively, by operating the operation key 4716, a signal is sent from the housing 4712 to the charger 4710, and a signal that can be transmitted by the charger 4710 is received by another electronic device, so that communication control of the other electronic device is performed. It may be a universal remote control device, which is possible. The present invention can be applied to the display portion 4713.

FIG. 56A shows a module in which a display panel 4801 and a printed wiring board 4802 are combined. The display panel 4801 includes a pixel portion 4803 provided with a plurality of pixels,
A first scan line driver circuit 4804, a second scan line driver circuit 4805, and a signal line driver circuit 4806 which supplies a video signal to a selected pixel are included.

The printed wiring board 4802 has a controller 4807 and a central processing unit (CPU) 480.
8, memory 4809, power supply circuit 4810, audio processing circuit 4811, and transmission/reception circuit 4812
And so on. The printed wiring board 4802 and the display panel 4801 are connected by a flexible wiring board (FPC) 4813. Flexible wiring board (FPC)
A storage capacitor, a buffer circuit, and the like are provided in the 4813 to generate noise in the power supply voltage or the signal.
Also, it may be configured to prevent the rise time of the signal from increasing. Note that the controller 4807
The audio processing circuit 4811, the memory 4809, the central processing unit (CPU) 4808, the power supply circuit 4810, and the like use a display panel 480 by a COG (Chip On Glass) method.
It can also be implemented in 1. The COG method can reduce the scale of the printed wiring board 4802.

Various control signals are input and output through an interface (I/F) unit 4814 provided on the printed wiring board 4802. An antenna port 4815 for transmitting/receiving a signal to/from the antenna is provided on the printed wiring board 4802.

FIG. 56(B) shows a block diagram of the module shown in FIG. 56(A). This module includes a VRAM 4816, a DRAM 4817, and a flash memory 48 as the memory 4809.
18 etc. are included. The VRAM4816 stores the data of the image displayed on the panel in the DR
Image data or audio data is stored in the AM4817, and various programs are stored in the flash memory.

The power supply circuit 4810 includes a display panel 4801, a controller 4807, a central processing unit (CP).
U) Power for operating the 4808, the voice processing circuit 4811, the memory 4809, and the transmission/reception circuit 4812 is supplied. However, depending on the panel specifications, the power supply circuit 4810 may be provided with a current source.

The central processing unit (CPU) 4808 includes a control signal generation circuit 4820, a decoder 4821, a register 4822, an arithmetic circuit 4823, a RAM 4824, and a central processing unit (CPU) 4808.
It has an interface (I/F) unit 4819 for use. Interface (I/
F) Various signals input to the central processing unit (CPU) 4808 via the unit 4819 are temporarily held in the register 4822 and then input to the arithmetic circuit 4823, the decoder 4821, and the like. The arithmetic circuit 4823 performs arithmetic operation based on the input signal and specifies a place to send various commands. On the other hand, the signal input to the decoder 4821 is decoded and the control signal generation circuit 4
820 is input. The control signal generation circuit 4820 generates a signal including various instructions based on the input signal, and a location specified in the arithmetic circuit 4823, specifically, the memory 480.
9, the transmission/reception circuit 4812, the voice processing circuit 4811, the controller 4807, and the like.

The memory 4809, the transmission/reception circuit 4812, the voice processing circuit 4811, and the controller 4807 operate in accordance with the received instructions. The operation will be briefly described below.

A signal input from the input unit 4825 is sent to the central processing unit (CPU) 4808 mounted on the printed wiring board 4802 via the interface (I/F) unit 4814.
The control signal generation circuit 4820 is an input unit 4 such as a pointing device or a keyboard.
According to the signal sent from 825, the image data stored in the VRAM 4816 is converted into a predetermined format and sent to the controller 4807.

A controller 4807 performs data processing on a signal including image data sent from a central processing unit (CPU) 4808 in accordance with panel specifications and supplies the signal to a display panel 4801. The controller 4807, based on the power supply voltage input from the power supply circuit 4810 or various signals input from the central processing unit (CPU) 4808, the Hsync signal, the Vsync signal, the clock signal CLK, the alternating voltage (AC Cont), Generates a switching signal L/R,
It is supplied to the display panel 4801.

In the transmission/reception circuit 4812, a signal transmitted/received as a radio wave in the antenna 4828 is processed, and specifically, an isolator, a bandpass filter, a VCO (Voltage).
Controlled Oscillator), LPF (Low Pass Filter)
er), couplers, baluns, and other high-frequency circuits. Among the signals transmitted and received by the transmission/reception circuit 4812, a signal including audio information is sent to the audio processing circuit 4811 in accordance with an instruction from the central processing unit (CPU) 4808.

A signal including audio information sent according to an instruction from the central processing unit (CPU) 4808 is demodulated into an audio signal in the audio processing circuit 4811 and sent to the speaker 4827. The audio signal sent from the microphone 4826 is modulated by the audio processing circuit 4811 and sent to the transmission/reception circuit 4812 in accordance with an instruction from the central processing unit (CPU) 4808.

The controller 4807, central processing unit (CPU) 4808, power supply circuit 4810, audio processing circuit 4811, and memory 4809 can be mounted as a package of this embodiment.

Of course, the present embodiment is not limited to the television receiver, and has various applications as a display medium of a particularly large area such as a monitor of a personal computer, an information display panel at a railway station or an airport, an advertisement display panel at the street, and the like. Can be applied.

Next, with reference to FIG. 57, a configuration example of the mobile phone according to the present invention will be described.

The display panel 4901 is detachably incorporated in the housing 4930. Housing 493
The shape of 0 can be appropriately changed according to the size of the display panel 4901. The housing 4930 to which the display panel 4901 is fixed is fitted into the printed board 4931 and assembled as a module.

The display panel 4901 is connected to the printed board 4931 through the FPC 4913. The printed board 4931 includes a speaker 4932, a microphone 4933, and a transmission/reception circuit 49.
34, a signal processing circuit 4935 including a CPU, a controller, and the like is formed. Such a module, the input means 4936, and the battery 4937 are combined to form a housing 493.
Store in 9. The pixel portion of the display panel 4901 is arranged so as to be visible through an opening window formed in the housing 4939.

In the display panel 4901, a pixel portion and part of a peripheral driver circuit (a driver circuit with a low operating frequency among a plurality of driver circuits) is formed over a substrate by using transistors, and a part of the peripheral driver circuit (a plurality of driver circuits) is formed. A driver circuit having a high operating frequency among the circuits may be formed over an IC chip and the IC chip may be mounted on the display panel 4901 by COG (Chip On Glass). Alternatively, the IC chip may be connected to the glass substrate by using TAB (Tape Auto Bonding) or a printed board. With such a structure, power consumption of the display device can be reduced and usage time of the mobile phone can be extended by one charge. The cost of the mobile phone can be reduced.

The mobile phone shown in FIG. 57 has a function of displaying various information (still images, moving images, text images, and the like). It has a function of displaying a calendar, date or time on the display unit. It has a function of operating or editing the information displayed on the display unit. It has a function of controlling processing by various software (programs). It has a wireless communication function. It has a function of making a call with another mobile phone, a landline phone, or a voice communication device by using the wireless communication function. It has a function of connecting to various computer networks by using a wireless communication function. It has a function of transmitting or receiving various data by using a wireless communication function. The vibrator has a function of operating in response to an incoming call, reception of data, or an alarm. It has a function to generate a sound in response to an incoming call, data reception, or an alarm. The function of the mobile phone shown in FIG. 57 is not limited to this.
It can have various functions.

The mobile phone shown in FIG. 58 includes a main body (A) 5001 provided with operation switches 5004, a microphone 5005, a display panel (A) 5008, and a display panel (B) 5009.
A main body (B) 5002 provided with a speaker 5006 and the like is connected with a hinge 5010 so that the main body (B) 5002 can be opened and closed. The display panel (A) 5008 and the display panel (B) 5009 are housed in the housing 5003 of the main body (B) 5002 together with the circuit board 5007. Display panel (A
) 5008 and the pixel portion of the display panel (B) 5009 are arranged so as to be visible through an opening window formed in the housing 5003.

For the display panel (A) 5008 and the display panel (B) 5009, specifications such as the number of pixels can be set as appropriate depending on the function of the mobile phone 5000. For example, the display panel (A) 5
It is possible to combine 008 as a main screen and the display panel (B) 5009 as a sub screen.

The mobile phone according to the present embodiment can be transformed into various modes depending on its function or application. For example, an image pickup device may be incorporated in the hinge 5010 to form a mobile phone with a camera. Operation switches 5004, display panel (A) 5008, display panel (B) 500
Even with the configuration in which 9 is housed in one housing, the above-described effects can be obtained. Similar effects can be obtained by applying the configuration of this embodiment to an information display terminal having a plurality of display units.

The mobile phone shown in FIG. 58 has a function of displaying various kinds of information (still images, moving images, text images, and the like). It has a function of displaying a calendar, date or time on the display unit. It has a function of operating or editing the information displayed on the display unit. It has a function of controlling processing by various software (programs). It has a wireless communication function. It has a function of making a call with another mobile phone, a landline phone, or a voice communication device by using the wireless communication function. It has a function of connecting to various computer networks by using a wireless communication function. It has a function of transmitting or receiving various data by using a wireless communication function. The vibrator has a function of operating in response to an incoming call, reception of data, or an alarm. It has a function to generate a sound in response to an incoming call, data reception, or an alarm. The function of the mobile phone shown in FIG. 58 is not limited to this.
It can have various functions.

The present invention can be applied to various electronic devices. Specifically, it can be applied to a display unit of an electronic device. Such electronic devices include video cameras, digital cameras, goggles type displays, navigation systems, sound reproduction devices (car audio systems, audio components, etc.), computers, game devices, personal digital assistants (mobile computers, mobile phones, portable games) Machine or electronic book, etc., an image reproducing device equipped with a recording medium (specifically, D
a device provided with a display capable of reproducing a recording medium such as an digital versatile disc (DVD) and displaying an image thereof.

FIG. 59A shows a display, which includes a housing 5111, a support base 5112, a display portion 5113, and the like. The display illustrated in FIG. 59A has a function of displaying various pieces of information (still images, moving images, text images, and the like) on a display portion. Note that the function of the display illustrated in FIG. 59A is not limited to this and can have various functions.

FIG. 59B illustrates a camera, which includes a main body 5121, a display portion 5122, an image receiving portion 5123, operation keys 5124, an external connection port 5125, a shutter button 5126, and the like. Fig. 59 (B
The camera shown in () has a function of capturing a still image. It has the function of shooting moving images. It has a function to automatically correct captured images (still images, moving images). It has a function of saving a captured image in a recording medium (external or built in a digital camera). It has a function of displaying a photographed image on the display portion. Note that the function of the camera illustrated in FIG. 59B is not limited to this and can have various functions.

FIG. 59C illustrates a computer, which includes a main body 5131, a housing 5132, a display portion 5133, a keyboard 5134, an external connection port 5135, a pointing device 5136, and the like. The computer illustrated in FIG. 59C has various kinds of information (still images, moving images, text images, and the like).
Has a function of displaying on the display unit. It has a function of controlling processing by various software (programs). It has a communication function such as wireless communication or wired communication. It has a function of connecting to various computer networks by using a communication function. It has a function of transmitting or receiving various data by using a communication function. Note that the functions of the computer illustrated in FIG. 59C are not limited to this and can have various functions.

FIG. 59D illustrates a mobile computer, which includes a main body 5141, a display portion 5142, a switch 5143, operation keys 5144, an infrared port 5145, and the like. The mobile computer illustrated in FIG. 59D has a function of displaying various pieces of information (still images, moving images, text images, and the like) on a display portion. The display has a touch panel function. The display unit has a function of displaying a calendar, date, time, and the like. It has a function of controlling processing by various software (programs). It has a wireless communication function. It has a function of connecting to various computer networks by using a wireless communication function. It has a function of transmitting or receiving various data by using a wireless communication function. The function of the mobile computer illustrated in FIG. 59D is not limited to this and can have various functions.

FIG. 59E illustrates a portable image reproducing device (eg, a DVD reproducing device) including a recording medium, which includes a main body 5151, a housing 5152, a display portion A5153, a display portion B5154, and a recording medium (
(DVD etc.) reading unit 5155, operation keys 5156, speaker unit 5157 and the like. The display portion A5153 can mainly display image information, and the display portion B5154 can mainly display textual information.

FIG. 59F is a goggle type display, which includes a main body 5161, a display portion 5162, earphones 5163, and a supporting portion 5164. The goggle type display shown in FIG. 59F has a function of displaying an image (a still image, a moving image, a text image, or the like) acquired from the outside on a display portion. Note that the function of the goggle type display illustrated in FIG. 59F is not limited to this and can have various functions.

FIG. 59G illustrates a portable game machine including a housing 5171, a display portion 5172, and a speaker portion 51.
73, operation keys 5174, a storage medium insertion portion 5175, and the like. A portable game machine in which the display device of the present invention is used for the display portion 5172 can express vivid colors. FIG. 59(G)
The portable game machine shown in 1 has a function of reading a program or data recorded in a recording medium and displaying the program or data on a display portion. It has a function of sharing information by performing wireless communication with other portable game machines. Note that the function of the portable game machine illustrated in FIG. 59G is not limited to this and can have various functions.

FIG. 59H illustrates a digital camera with a television receiving function, which includes a main body 5181 and a display portion 518.
2, operation key 5183, speaker 5184, shutter button 5185, image receiving portion 518
6, an antenna 5187 and the like are included. The digital camera with a television receiver illustrated in FIG. 59H has a function of shooting a still image. It has the function of shooting moving images. It has a function to automatically correct the captured image. It has a function of acquiring various information from the antenna. It has a function of saving a captured image or information acquired from the antenna. It has a function of displaying a captured image or information acquired from an antenna on a display portion. The function of the digital camera with a television receiver illustrated in FIG. 59H is not limited to this and can have various functions.

As shown in FIGS. 59A to 59E, the electronic device of the present invention is characterized by having a display portion for displaying some information. Since the electronic device according to the present invention can reduce the frequency of circuit operation by storing the data in the memory when the data is duplicated, the power consumption is low, and the battery can be driven for a long time. is there.
Next, application examples of the display device according to the present invention will be described.

FIG. 60 shows an example in which the display device of the present invention is incorporated in a building. Fig. 60
Indicates a building including a housing 5200, a display panel 5201, a speaker portion 5202, and the like. Reference numeral 5203 denotes a remote control device for operating the display panel 5201.

The pixel described in any of the above embodiments is used for the display panel 5201. According to the present invention, it is possible to obtain a display panel having excellent display angle characteristics and high display quality. Note that cost can also be reduced by using a transistor of the same conductivity type for a transistor included in a pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

Since the display device shown in FIG. 60 is provided integrally with a structure, it can be installed without requiring a large space.

FIG. 61 shows another example in which the display device according to the present invention is incorporated in a building. The display panel 5301 is attached integrally with the unit bath 5302, so that a bather can watch the display panel 5301 while taking a bath. Information can be displayed on the display panel 5301 by being operated by a bather. Therefore, it has a function that can be used as an advertisement or entertainment means.

The pixel described in any of the above embodiments is used for the display panel 5301. According to the present invention, it is possible to obtain a display panel having excellent display angle characteristics and high display quality. Note that cost can also be reduced by using a transistor of the same conductivity type for a transistor included in a pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

Note that the display device according to the present invention can be provided not only at the side wall of the unit bus 5302 shown in FIG. 61 but also at various places integrally. For example, it may be provided integrally with a part of the mirror surface or the bathtub itself. Further, the shape of the display device may be adapted to the shape of the mirror surface or the bathtub.

FIG. 62 shows another example in which the display device of the present invention is incorporated in a building.
In FIG. 62, the display panel 5402 is curved to match the curved surface of the columnar body 5401. Here, the columnar body 5401 will be described as an electric pole.

The display panel 5402 shown in FIG. 62 is provided at a position higher than the human viewpoint. By installing the display panel 5402 in a building which is repeatedly forested outdoors such as a telephone pole, information can be provided to an unspecified number of viewers through the display panel 5402. Therefore, it is suitable to use the display panel as an advertisement. Further, the display panel 5402 can easily display the same image by an external control and can instantly switch the images, so that extremely efficient information display and advertisement effect can be expected. Also, the display panel 5
It can be said that by providing a self-luminous display element in 402, it is useful as a display medium with high visibility even at night. In addition, by installing the display panel 5402 on a power pole, the display panel 5402
It is easy to secure the power supply means of 402. In the event of an emergency such as a disaster,
It can also be a means of quickly and accurately transmitting information to victims.

The pixel described in any of the above embodiments is used for the display panel 5402. According to the present invention, it is possible to obtain a display panel having excellent display angle characteristics and high display quality. Note that cost can also be reduced by using a transistor of the same conductivity type for a transistor included in a pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor. Alternatively, an organic transistor provided on a film-shaped substrate may be used.

In the present embodiment, a wall, a unit bath, and a building are integrated with the display device of the present invention.
Although the columnar body is exemplified, it can be provided in various other structures.

Next, an example in which the display device according to the present invention is provided integrally with a moving object will be described.

FIG. 63 is a diagram showing an example in which the display device according to the present invention is provided integrally with an automobile. The display panel 5502 is provided so as to be integrated with a vehicle body 5501 of an automobile, and can display on-demand information of the operation of the vehicle body and information input from inside and outside the vehicle body. The display panel 5502 may have a navigation function.

The pixel described in any of the above embodiments is used for the display panel 5502. According to the present invention, it is possible to obtain a display panel having excellent display angle characteristics and high display quality. Note that cost can also be reduced by using a transistor of the same conductivity type for a transistor included in a pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

The display device according to the present invention can be provided not only in the vehicle body 5501 shown in FIG. 63 but also in various places. For example, it may be integrated with a glass window, a door, a handle, a shift lever, a seat, a rearview mirror, or the like. At this time, the shape of the display panel 5502 may match the shape of the object to be installed.

FIG. 64 is a diagram showing an example in which the display device according to the present invention is provided integrally with a train car.

FIG. 64A is a diagram showing an example in which the display panel 5602 is provided on the glass of the door 5601 of the train car. Compared to conventional paper advertisements, there is an advantage that labor costs required for advertisement switching are not required. Further, since the display panel 5602 can instantaneously switch the image displayed on the display portion by a signal from the outside, for example, the image of the display panel is displayed at each time when the passenger class of train passengers is switched. You can switch.
Immediate switching of images in this manner can be expected to have a more effective advertising effect.

FIG. 64B is a diagram showing an example in which a display panel 5602 is provided in a glass window 5603 and a ceiling 5604 in addition to the glass of the door 5601 of the train car. As described above, since the display device according to the present invention can be easily installed in a place where it has been difficult to install the display device in the related art, an effective advertising effect can be obtained. Further, since the display device according to the present invention can instantly switch the image displayed on the display unit by a signal from the outside, it is possible to reduce the cost and time that have occurred at the time of switching the advertisement, and to be more flexible. It is possible to operate various types of advertisements and communicate information.

Note that the pixel described in any of the above embodiments is used for the display panel 5602 shown in FIG. According to the present invention, it is possible to obtain a display panel having excellent display angle characteristics and high display quality. Note that cost can also be reduced by using a transistor of the same conductivity type for a transistor included in a pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

Further, the display device according to the present invention is not limited to the above, and can be provided in various places. For example, the display device according to the present invention may be integrally provided with a strap, a seat, a handrail, a floor, and the like. At this time, the shape of the display panel 5602 may match the shape of the object to be installed.

FIG. 65 is a diagram showing an example in which the display device according to the present invention is provided integrally with a passenger airplane.

FIG. 65(a) is a diagram showing a shape in use when a display panel 5702 is provided on a ceiling 5701 above a seat of a passenger airplane. The display panel 5702 has a hinge portion 570.
3 is provided integrally with the ceiling 5701 through the hinge 3, and the expansion and contraction of the hinge portion 5703 enables passengers to view the display panel 5702 at a desired position. The display panel 5702 can display information by being operated by a passenger. Therefore, it has a function that can be used as an advertisement or entertainment means. In addition, as shown in FIG. 65(b), the hinge portion is bent and the ceiling 570 is
By storing the data in No. 1, it is possible to consider safety during takeoff and landing. By turning on the display element of the display panel 5702 in an emergency, it can be used as an information transmitting unit and a guide light.

Note that the pixel described in any of the above embodiments is used for the display panel 5702 shown in FIG. According to the present invention, it is possible to obtain a display panel having excellent display angle characteristics and high display quality. Note that cost can also be reduced by using a transistor of the same conductivity type for a transistor included in a pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

Note that the display device according to the present invention can be provided not only in the ceiling 5701 shown in FIG. For example, it may be provided integrally with a seat, a seat table, an armrest, a window and the like. In addition, a large display panel that can be viewed by many people at the same time may be installed on the wall of the machine body. At this time, the shape of the display panel 5702 may match the shape of the object to be installed.

In the present embodiment, the moving body is exemplified by a train car body, an automobile body, and an airplane body, but the moving body is not limited to these. A motorcycle, a four-wheeled vehicle (including a car, a bus, etc.)
Various things such as trains, trains (including monorails, railways, etc.), ships, etc. can be applied. Since the display device according to the present invention can instantaneously switch the display of the display panel in the moving body by a signal from the outside, by installing the display device according to the present invention in the moving body, the moving body is disabled. It can be used as an advertisement display board for a large number of specified customers, an information display board when a disaster occurs, and the like.

In the present embodiment, various drawings are used for description, but the contents described in each drawing (
(May be a part) applies to or applies to the contents (may be a part) described in another figure,
Alternatively, replacement or the like can be freely performed. Further, in each of the drawings described so far, more drawings can be formed by combining each part with another part.

Similarly, the content (may be part) described in each drawing of this embodiment is applied to or combined with the content (may be part) described in the drawings of other embodiments and examples. , Or replacement can be freely performed. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each part with parts of another embodiment mode and examples.

Note that in this embodiment, the contents (may be part) described in the other embodiments and examples are
Example of embodying, example of slightly deforming, example of partially changing, example of improving, example of detailed description, example of application, example of related parts And so on. Therefore, the contents described in other embodiment modes and examples can be freely applied to, combined with, or replaced with this embodiment mode.

11 node 30 TFT
3a Scan line 63 Switch 6a Data line (signal line)
111 first switch 112 second switch 113 third switch 114 first resistor 115 second resistor 116 signal line 117 first scan line 118 common electrode 119 Cs line 120 second scan line 121 first Liquid crystal element 122 Second liquid crystal element 131 First storage capacitor 132 Second storage capacitor 141 Node 142 Node 201 Third scan line 212 Second transistor 311 Signal line driver circuit 312 Scan line driver circuit 313 Pixel portion 314 Pixel 500 pixels 517 first scan line 612 second transistor 613 third transistor 620 transistor 621 transistor 821 transistor 920 transistor 910 transistor 1014 transistor 1114 transistor 1200 node 1201 unit 1214 transistor 1223 liquid crystal element 1233 storage capacitor 1414 transistor 1601 third storage capacitor 1712 Second Switch 1722 Second Transistor 1733 Third Switch 1743 Third Transistor 1750 Transistor 1751 Liquid Crystal Element 1752 Retaining Capacitance 1901 Third Retaining Capacitance 1911 Third Retaining Capacitance 1921 Third Retaining Capacitance 1922 Node 1923 Node 1924 transistor 1931 third storage capacitor 1932 node 8300 wiring 8411 first transistor 1300a sub pixel 1300b sub pixel 1400a sub pixel 1400b sub pixel 1500a sub pixel 1500b sub pixel 1600a sub pixel 1600b sub pixel

Claims (1)

The pixel includes a first transistor, a second transistor, a first liquid crystal element, and a first storage capacitor,
A gate of the first transistor and a gate of the second transistor are electrically connected to a first scan line,
One of a source and a drain of the first transistor is electrically connected to a signal line,
The other of the source and the drain of the first transistor is one of the source and the drain of the second transistor, the pixel electrode of the first liquid crystal element, and the first electrode of the first storage capacitor, Device electrically connected to the.

Images