JP2014197202A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-quality liquid crystal display device excellent in viewing angle characteristics.SOLUTION: The liquid crystal display device has a pixel including a first switch 111, a second switch 112, a third switch 113 controlled by a timing different from the first switch and the second switch, a first resistor 114, a second resistor 115, a first liquid crystal element 121 and a second liquid crystal element 122. A pixel electrode of the first liquid crystal element is electrically connected to a signal line 116 via the first switch, and to a pixel electrode of the second liquid crystal element via the second switch and the first resistor. The pixel electrode of the second liquid crystal element is electrically connected to a Cs line 119 via the third switch and the second resistor, and a common electrode of the first liquid crystal element is electrically connected to a common electrode of the second liquid crystal element. High quality display excellent in viewing angle characteristics can be achieved by inputting a potential according to the gradation of the pixel to the signal line.

Description

The present invention relates to an object, a method, or a method of producing an object. 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 electrical products such as mobile phones and television receivers, and many studies have been made for further improvement in quality.

A liquid crystal display device is advantageous in that it is smaller and lighter than a CRT (CRT) and consumes less power, but has a problem of a narrow viewing angle. In recent years, many studies on the multi-domain method, that is, the alignment division method, have been made in order to improve the viewing angle characteristics. For example, MVA method (Multi-domain Vertical Al) that combines multi-domain method with VA method (Vertical Alignment; vertical alignment method)
ignition; multi-domain vertical alignment method) and PVA method (Patterned)
Vertical Alignment (pattern type vertical alignment method).

In addition, 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 the liquid crystal in each sub-pixel (Patent Document 1).

JP 2006-276582 A

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

FIG. 84 shows an equivalent circuit diagram of one pixel of the liquid crystal display device described in Patent Document 1. FIG.
4 includes a TFT 30, a liquid crystal capacitor L1, a liquid crystal capacitor L2, a storage capacitor C1, and a storage capacitor C2, and is connected to the scanning line 3a and the data line (signal line) 6a.

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

In view of the above problems, an object of the present invention is to realize wide viewing angle display. Another object is to provide a display device with excellent contrast. Alternatively, it is an object to provide a display device with excellent display quality. Alternatively, it is an object to provide a display device that is not easily affected by noise and can perform a beautiful display. Another object is to provide a display device in which display deterioration is unlikely to occur. Another object is to provide a display device with 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 the second scanning line, A pixel including a first resistor, a second resistor, a first liquid crystal element, and a second liquid crystal element, and each of the first liquid crystal element and the second liquid crystal element includes at least a pixel electrode A pixel electrode and a liquid crystal controlled by the common electrode, and the pixel electrode of the first 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 The pixel electrode is electrically connected to the second wiring through the third switch and the second resistor. Is connected, the common electrode of the first liquid crystal element is a liquid crystal display device characterized by being electrically connected to the common electrode of the second liquid crystal element.

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 the second scanning line, A pixel including a first resistance, a second resistance, a first liquid crystal element, a second liquid crystal element, a first storage capacitor, and a second storage capacitor, the first liquid crystal element And each of the second liquid crystal elements includes 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 through the first switch, and the pixel electrode of the first liquid crystal element includes the second switch and the first switch. The pixel electrode of the second liquid crystal element is electrically connected to the second wiring via the third switch and the second resistor. The pixel electrode of the first liquid crystal element is electrically connected to the second wiring through the first storage capacitor, and the pixel electrode of the second liquid crystal element is The second wiring is electrically connected to the second wiring through 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. This is a liquid crystal display device.

According to one aspect of the present invention, the first switch controlled by the third scanning line, the second switch controlled by the first scanning line, and the first scanning line and the second scanning line are controlled. A pixel including a third switch, a first resistor, a second resistor, a first liquid crystal element, and a second liquid crystal element, wherein the first liquid crystal element and the second liquid crystal element Each of the liquid crystal elements includes at least a pixel electrode,
The first electrode includes a common electrode, and the 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 through the second switch and the first resistor, and the pixel electrode of the second liquid crystal element 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. The liquid crystal display device is connected to the liquid crystal display device.

According to one aspect of the present invention, the first switch controlled by the third scanning line, the second switch controlled by the first scanning line, and the first scanning line and the second scanning line are controlled. A pixel including a third switch, a first resistor, a second resistor, a first liquid crystal element, and a second liquid crystal element, wherein the first liquid crystal element and the second liquid crystal element Each of the liquid crystal elements includes at least a pixel electrode,
The first electrode includes a common electrode, and the 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 through the second switch and the first resistor, and the pixel electrode of the second liquid crystal element Is electrically connected to the second wiring through the third switch and the second resistor, and the pixel electrode of the first liquid crystal element is connected to the second wiring through the first storage capacitor. And the pixel electrode of the second liquid crystal element is electrically connected to the second wiring via the second storage capacitor, and is connected to the common electrode of the first liquid crystal element. Is a liquid crystal display device electrically connected to the 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, in which a resistance value of the second resistor is larger than a resistance value of the first resistor.

One embodiment of the present invention is 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. And a second storage capacitor, the gate electrode of the first transistor is electrically connected to the first scan line, and the gate electrode of the second transistor is the first electrode. 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,
A liquid crystal controlled by the pixel electrode and the common electrode, wherein the pixel electrode of the first liquid crystal element is electrically connected to a first wiring via the switch, and the first liquid crystal element The pixel electrode of the second liquid crystal element is electrically connected to the pixel electrode of the second liquid crystal element through the first transistor, and the pixel electrode of the second liquid crystal element is connected to the second transistor through the second transistor. 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 to the second liquid crystal element. Is electrically connected to the second wiring through the second storage capacitor, and the common electrode of the first liquid crystal element is
A liquid crystal display device, wherein the liquid crystal display device is electrically connected to a common electrode of the second liquid crystal element.

One embodiment 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. The gate electrodes of the first transistor and the third transistor are electrically connected to the first scan line, and the gate electrode of the second transistor is the first transistor. The first liquid crystal is a 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 includes the first electrode 3 Is electrically connected to the first wiring through the transistor,
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 connected to the second liquid crystal element. A second wiring is electrically connected through a transistor, and a pixel electrode of the first liquid crystal element is electrically connected to the second wiring through the first storage capacitor, and the second wiring is connected to the second wiring. The pixel electrode of the liquid crystal element is electrically connected to the second wiring through 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. A liquid crystal display device which is electrically connected.

According to one embodiment of the present invention, when the channel width of the transistor is W and the channel length is L in the above structure, the W / L of the third transistor is greater than the W / L of the first transistor or the second transistor. The liquid crystal display device is 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, the W / L of the second transistor is larger than the W / L of the first transistor. It is a liquid crystal display device.

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

Note that various types of switches can be used. Examples include electrical switches and mechanical switches. In other words, anything that can control the current flow,
It is not limited to a specific thing. For example, as a switch, a transistor (for example, bipolar transistor, MOS transistor, etc.), a diode (for example, PN diode, P, etc.)
IN diode, Schottky diode, MIM (Metal Insulator)
Metal diode, MIS (Metal Insulator Semiconductor)
uctor) diodes, diode-connected transistors, etc.), thyristors, etc. can be used. Alternatively, a logic circuit combining these 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 moved mechanically, and operates by controlling connection and disconnection by moving the electrode.

In the case where a transistor is used as a switch, the transistor operates as a mere switch, and thus the polarity (conductivity type) of the transistor is not particularly limited. However, when it is desired to suppress off-state current, it is desirable to use a transistor having a polarity with 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, and the like can be given. Alternatively, an N-channel transistor is preferably used in the case where the transistor operates as a switch when the potential of the source terminal of the transistor is close to the potential of the low potential power supply (Vss, GND, 0 V, or the like). On the other hand, it is desirable to use a P-channel transistor when operating in a state where the potential of the source terminal is close to the potential of the high potential side power supply (Vdd or the like). This is because an N-channel transistor operates when the source terminal is close to the potential of the low-potential side power supply, and a P-channel transistor operates when the source terminal is close to the potential of the high-potential side power supply. This is because the absolute value of the voltage between them can be increased, so that it can easily operate as a switch. Moreover, since the source follower operation is rarely performed, the output voltage is rarely reduced.

Note that both N-channel and P-channel transistors are used for CMOS.
A type switch may be used as the switch. When a CMOS switch is used, a current flows when one of the P-channel transistor and the N-channel transistor is turned on, so that the switch can easily function 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 on and off the switch can be reduced, the power consumption can be reduced.

Note that when a transistor is used as a switch, the switch has an input terminal (one of a source terminal or a drain terminal), an output terminal (the other of the source terminal or 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, the use of a diode as a switch rather than a transistor can reduce the wiring for controlling the terminal.

In addition, when it is explicitly described that A and B are connected, A and B are electrically connected, and 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 relationship shown in the figure or text, and includes things other than the connection relationship shown in the figure or text.

For example, when A and B are electrically connected, an element (for example, a switch, a transistor, a capacitor, an inductor, a resistance element, a diode, or the like) that enables electrical connection between A and B is provided. 1 or more may be arranged between A and B. Alternatively, when A and B are functionally connected, a circuit (for example, a logic circuit (an inverter, a NAND circuit, a NOR circuit, etc.), a signal conversion circuit that enables functional connection between A and B (DA conversion circuit, AD conversion circuit, gamma correction circuit, etc.), potential level conversion circuit (power supply circuit (boost circuit,
Step-down circuit), level shifter circuit that changes signal potential level), voltage source, current source,
Switching circuit, amplifier circuit (circuit that can increase signal amplitude or current, etc., operational amplifier,
One or more differential amplifier circuits, source follower circuits, buffer circuits, etc.), signal generation circuits, memory circuits, control circuits, etc.) may be arranged between A and B. Alternatively, when A and B are directly connected, A and B without interposing other elements or other circuits between A and B.
And may be directly connected.

Note that in the case where it is explicitly described that A and B are directly connected, when A and B are directly connected (that is, another element or other circuit between A and B). ) And A and B are electrically connected (that is, A and B are connected with another element or another circuit sandwiched between them). ).

Note that in the case where it is explicitly described that A and B are electrically connected, another element is connected between A and B (that is, between A and B). Or when A and B are functionally connected (that is, they are functionally connected with another circuit between A and B). And a case where A and B are directly connected (that is, a case where another element or another circuit is not connected between A and B). That is, when it is explicitly described that it is electrically connected, it is the same as when it is explicitly only described that it is 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 include 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 including an organic substance and an inorganic substance, an organic EL element, an inorganic EL element), an electron emitting element, a liquid crystal element, electronic ink, an electrophoretic element, Grating light bulb (GLV), plasma display (PD
P), a digital micromirror device (DMD), a piezoelectric ceramic display, a carbon nanotube, or the like can be used a display medium whose contrast, brightness, reflectance, transmittance, and the like are changed by an electromagnetic action. Note that 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.
As a display device using a liquid crystal element, such as a nudection electron-emitter display, a liquid crystal display (a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, a direct view liquid crystal display, a projection liquid crystal display), electronic ink, 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
Those using light emission (phosphorescence) from singlet excitons, those using light emission (fluorescence) from singlet excitons, and those using light emission (phosphorescence) from triplet excitons , Organic materials, inorganic materials, organic materials and inorganic materials, high molecular materials, low molecular materials, high molecular materials and low molecules A material containing any of these materials can be used. However, it is not limited to this, E
Various elements can be used as the L element.

The electron-emitting device is an element that draws electrons by concentrating a high electric field on a sharp cathode. For example, as an electron-emitting device, a Spindt type, a carbon nanotube (CNT) type, a metal-insulator-metal laminated MIM (Metal-Insulator-Metal) type, and a metal-insulator-semiconductor laminated MIS (Metal-Insulator). -Semicon
(ductor) 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 thin film type, HEED, etc. A type, an EL type, a porous silicon type, a surface conduction (SED) type, or the like can be used. However, the present invention is not limited to this, and various types of electron-emitting devices can be used.

Note that a 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). Liquid crystal elements include nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, discotic liquid crystal, thermotropic liquid crystal, lyotropic liquid crystal, lyotropic liquid crystal, low molecular 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.)
tick alignment mode, PVA (Patterned Vertic)
al Alignment), ASV (Advanced Super View) mode, ASM (Axial Symmetrical Aligned Micro-ce)
ll) mode, OCB (Optical Compensated Birefring)
ence) mode, ECB (Electrically Controlled Bird)
efficiency mode, FLC (Ferroelectric Liquid)
Crystal) mode, AFLC (Antiferroelectric Liquid)
d Crystal) mode, PDLC (Polymer Dispersed Liq)
uid Crystal) mode, guest host mode, etc. can be used. However, the present invention is not limited to this, and various liquid crystal elements can be used.

Electronic paper includes those 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. It is displayed by moving, displayed by color development / phase change of molecules, displayed by light absorption of molecules, displayed by self-emission by combining electrons and holes, etc. . 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 heat sensitivity 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 microcapsule electrophoresis, aggregation and precipitation of electrophoretic particles, which is a drawback of the electrophoresis system, can be solved. The electronic powder fluid has advantages such as high-speed response, high reflectivity, wide viewing angle, low power consumption, and memory properties.

Note that the plasma display encloses a rare gas with a substrate having an electrode formed on the surface and a substrate having an electrode and a minute groove formed on the surface and a phosphor layer formed in the groove facing each other at a narrow interval. It has a structure. In addition, a display can be performed by generating an ultraviolet-ray by applying a voltage between electrodes and making fluorescent substance light. As a plasma display, DC
It may be a type PDP or an AC type PDP. Here, as a plasma display panel, AS
W (Address While Sustain) drive, ADS (Address Display Sep) that divides subframe into reset period, address period, and sustain period
driven), CLEAR (Low Energy Address and R)
instruction of false control sequence) drive, AL
IS (Alternate Lightning of Surfaces) method, TER
An ES (Technology of Reciprocal Susfainer) 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.

Note that a display device that requires a light source, such as a liquid crystal display (transmission type liquid crystal display, transflective type liquid crystal display, reflection type liquid crystal display, direct view type liquid crystal display, projection type liquid crystal display), a grating light valve (GLV) As a light source for a display device using a conventional display device or a digital micromirror device (DMD), electroluminescence, a cold cathode tube, a hot cathode tube, an LED, a laser light source, a mercury lamp, or the like can be used. However, the present invention 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) including 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. When using TFT, there are various advantages. For example, since manufacturing can be performed at a lower temperature than that of single crystal silicon, manufacturing cost can be reduced or a manufacturing apparatus can be increased in size. 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, it can be manufactured at low cost. Furthermore, since the manufacturing temperature is low, a substrate with low heat resistance can be used. Therefore, a transistor can be manufactured on a transparent substrate. Then, light transmission through the display element can be controlled using a transistor over a 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 crystallinity and to manufacture a transistor with favorable electrical characteristics. As a result, a gate driver circuit (scan line driver circuit) and a source driver circuit (signal line driver circuit)
The signal processing circuit (signal generation circuit, gamma correction circuit, DA conversion circuit, etc.) can be integrally formed on the substrate.

Note that when a microcrystalline silicon is manufactured, by using a catalyst (such as nickel), crystallinity can be further improved and a transistor with favorable electrical characteristics can be manufactured. At this time, crystallinity can be improved only by performing heat treatment without performing laser light irradiation. As a result, a part of the gate driver circuit (scanning line driver circuit) and the source driver circuit (analog switch or the like) can be integrally formed on the substrate. Further, when laser 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 produce polycrystalline silicon or microcrystalline silicon without using a catalyst (such as nickel).

Note that it is preferable to improve the crystallinity of silicon to be polycrystalline or microcrystalline, but the present invention is not limited to this. The crystallinity of silicon may be improved only in a partial region of the panel. The crystallinity can be selectively improved by selectively irradiating laser light. For example, the laser beam may be irradiated only to the peripheral circuit region that is a region other than the pixel. Alternatively, the laser beam may be irradiated only on a region such as a gate driver circuit or a source driver circuit. Or you may irradiate a laser beam only to the area | region (for example, analog switch) of a source driver circuit. as a result,
Silicon crystallization can be improved only in regions 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 the region for improving crystallinity is small, the manufacturing process can be shortened, the throughput can be improved, and the manufacturing cost can be reduced. In addition, the manufacturing cost can be reduced because the number of manufacturing apparatuses required is small.

Alternatively, a transistor can be formed using a semiconductor substrate, an SOI substrate, or the like. Accordingly, a transistor with small variations in characteristics, size, shape, and the like, high current supply capability, and small size can be manufactured. When these transistors are used, low power consumption of the circuit or high integration of the circuit can be achieved.

Alternatively, a transistor having 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 semiconductor or oxide semiconductor is thinned can be used. I can do it. Accordingly, 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, such as a plastic substrate or a film substrate. These compound semiconductors or oxide semiconductors are
It can be used not only for the channel portion of the transistor but also for other purposes. For example, these compound semiconductors or oxide semiconductors can be used as resistance elements, pixel electrodes, and transparent electrodes. Furthermore, since these can be formed or formed simultaneously with the transistor, cost can be reduced.

Alternatively, a transistor formed using an inkjet method or a printing method can be used. By these, it can manufacture at room temperature, manufacture at a low vacuum degree, or can manufacture on a large sized substrate. Further, since the transistor can be manufactured without using a mask (reticle), the layout of the transistor can be easily changed. Furthermore, since it is not necessary to use a resist, the material cost is reduced and the number of processes can be reduced. Further, since a film is formed only on a necessary portion, the material is not wasted and cost can be reduced as compared with a manufacturing method in which etching is performed after film formation on the entire surface.

Alternatively, a transistor including an organic semiconductor or a carbon nanotube can be used. Thus, a transistor can be formed over a substrate that can be bent.
Therefore, it can be strong against impact.

In addition, 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 a MOS transistor, the size of the transistor can be reduced. Therefore, a large number of transistors can be mounted. By using a bipolar transistor, a large current can flow. Therefore, the circuit can be operated at high speed.

Note that a MOS transistor, a bipolar transistor, or the like may be formed over one substrate. Thereby, 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 kind of board | substrate is not limited to a specific thing. As a substrate on which a transistor is formed, for example, a single crystal substrate, an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a paper substrate, a cellophane substrate, a stone substrate, a wood substrate, a cloth substrate (natural fiber (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 (skin surface, dermis) or subcutaneous tissue of an animal such as a human may be used as the substrate. Alternatively, a transistor may be formed using a certain substrate, and then the transistor may be transferred to another substrate, and the transistor may be disposed on another substrate. As a substrate to which the transistor is transferred, a single crystal substrate, an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a paper substrate, a cellophane substrate, a stone substrate, a wood substrate, a cloth substrate (natural fiber (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. Can do. Or the skin of human 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 and thinned. 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 stainless steel, still foil, or the like can be used. Alternatively, the skin (skin surface, dermis) or subcutaneous tissue of an animal such as a human may be used as the substrate. By using these substrates, formation of transistors with good characteristics, formation of transistors with low power consumption, manufacture of devices that are difficult to break,
The heat resistance can be imparted, the weight can be reduced, or the thickness can be reduced.

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

Alternatively, a structure in which a gate electrode is disposed over a channel region may be employed, or a structure in which a gate electrode is disposed under a channel region may be employed. Alternatively, a normal stagger structure or an inverted stagger structure may be used, 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,
A source electrode or a drain electrode may overlap with the channel region (or a part thereof).
With the structure in which the source electrode or the drain electrode overlaps with the channel region (or part of it), it is possible to prevent electric charges from being accumulated in part of the channel region and unstable operation. Further, an LDD region may be provided. By providing the LDD region, the off-state current can be reduced or the 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 so much and the slope of the voltage / current characteristic is flat. it can.

Note that various types of transistors can be used, and the transistor can be formed using various substrates. Therefore, all of the circuits necessary for realizing a predetermined function may be formed on the same substrate. For example, all the circuits necessary for realizing a predetermined function may be formed using a glass substrate, a plastic substrate, a single crystal substrate, or an SOI substrate, and are formed using various substrates. Also good. Since all the circuits necessary to realize a given function are formed using the same substrate, the cost can be reduced by reducing the number of components, or the reliability can be improved by reducing the number of connection points with circuit components. Can be planned. Alternatively, a part of the circuit necessary for realizing the predetermined function is formed on a certain substrate, and another part of the circuit necessary for realizing the predetermined function is formed on another substrate. It may be. That is, not all the circuits necessary for realizing a predetermined function may be formed using the same substrate. For example, a part of a circuit necessary for realizing a predetermined function is formed using a transistor over a glass substrate, and another part of a circuit required for realizing a predetermined function is a single crystal substrate. The IC chip formed on the single crystal substrate and formed of a transistor may be connected to the glass substrate by COG (Chip On Glass), and the IC chip may be arranged on the glass substrate. Alternatively, 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, since a part of the circuit is formed on the same substrate, the cost can be reduced by reducing the number of components, or the reliability can be improved by reducing the number of connection points with circuit components. In addition, since the power consumption of a circuit having a high driving voltage or a high driving frequency is large, such a circuit is not formed on the same substrate. Instead, for example, on a single crystal substrate. If the circuit of that portion is formed and an IC chip constituted by the circuit is used, an increase in power consumption can be prevented.

One pixel means one element whose brightness can be controlled. Therefore, as an example, one pixel represents one color element, and brightness is expressed by one color element.
Therefore, at that time, in the case of a color display device composed of R (red), G (green), and B (blue) color elements, the minimum unit of an image is an R pixel, a G pixel, and a B pixel. It is assumed to be composed of three pixels. Note that 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. R
For example, one or more colors such as yellow, cyan, magenta, emerald green, and vermilion may be added to GB. Also, for example, a color similar to at least one of RGB is changed to RGB
May be added to For example, R, G, B1, and B2 may be used. B1 and B2 are both blue, but have slightly different frequencies. Similarly, R1, R2, G, and B may be used. By using such color elements, it is possible to perform display closer to the real thing. Alternatively, power consumption can be reduced by using such color elements. Also,
As another example, when controlling brightness using a plurality of areas for one color element,
One area may be a pixel. Therefore, as an example, when area gradation is performed or when sub-pixels (sub-pixels) are provided, there are a plurality of brightness control areas for one color element, and the gradation is expressed as a whole. However, one pixel 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 areas for controlling the brightness in one color element, they may be combined into one pixel. Therefore, in that case, one color element is composed of one pixel. When brightness is controlled using a plurality of areas for one color element, the size of the area contributing to display may be different depending on the pixel. In addition, in a plurality of brightness control areas for one color element, the signal supplied to each may be slightly different to widen the viewing angle. That is, 1
For one color element, the potentials of the pixel electrodes in each of the plurality of regions may be different from each other. As a result, the voltage applied to the liquid crystal molecules is different for each pixel electrode. Therefore, the viewing angle can be widened.

In addition, when it is explicitly described as one pixel (for three colors), it is assumed that three pixels of R, G, and B are considered as one pixel. When it is explicitly described as one pixel (for one color), it is assumed that when there are a plurality of areas for one color element, they are considered as one pixel.

Note that in this document (the specification, the claims, the drawings, or the like), the pixels may be arranged (arranged) in a matrix. Here, the pixel being arranged (arranged) in the matrix includes a case where the pixels are arranged in a straight line or a jagged line in the vertical direction or the horizontal direction. Thus, for example, three color elements (for example, R
When full-color display is performed in GB), this includes the case where stripes are arranged and the case where dots of three color elements are arranged in delta. Furthermore, the case where a Bayer is arranged is included. Note that the color elements are not limited to three colors, and may be more than that, for example, RGBW (W is white) or RGB in which one or more colors of yellow, cyan, magenta, etc. are added.
Further, the size of the display area may be different for each dot of the color element. Thereby, it is possible to reduce 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 and nonlinear elements) can be used as active elements (active elements and nonlinear elements). For example, MIM (Metal Insulator Metal) or TFD (
It is also possible to use (Thin Film Diode) or the like. Since these elements have few manufacturing processes, 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 luminance can be achieved.

Note that as a method other than the active matrix method, a passive matrix type that does not use active elements (active elements, nonlinear elements) can be used. Since no active element (active element or nonlinear element) is used, the number of manufacturing steps is small, and manufacturing cost can be reduced or yield can be improved. In addition, since an active element (an active element or a non-linear element) is not used, the aperture ratio can be improved, and low power consumption and high luminance can be achieved.

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

Note that the transistor may be an element having at least three terminals including a base, an emitter, and a collector. Similarly, in this case, the emitter and collector are connected to the first terminal and the second terminal.
Sometimes referred to as a terminal.

Note that a gate refers to the whole or part of 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). A gate electrode refers to a portion of a conductive film that overlaps with a semiconductor forming a channel region with a gate insulating film interposed therebetween. Note that a part of the gate electrode is an LDD (Lightly Dop
ed Drain) region or source region (or drain region) may overlap with the gate insulating film. A gate wiring is a wiring for connecting the gate electrodes of each transistor, a wiring for connecting the gate electrodes of each pixel, or a wiring for connecting the gate electrode to another wiring. Say.

However, there are portions (regions, conductive films, wirings, etc.) that also function as gate electrodes and function as gate wirings. Such a portion (region, conductive film, wiring, or the like) may be called 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, when a part of the gate wiring extended and the channel region overlap, the portion (region, conductive film, wiring, etc.) functions as the gate wiring, but also as the gate electrode It is functioning. Therefore, such a portion (region, conductive film, wiring, or the like) may be called a gate electrode or a gate wiring.

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

Note that, for example, in a multi-gate transistor, one gate electrode and another gate electrode are often connected to each other with 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 to the gate electrode, and may be called a gate wiring. These transistors can be regarded as a single transistor, and may be referred to as a gate electrode. That is, a portion (region, conductive film, wiring, or the like) that is formed using the same material as the gate electrode or gate wiring and is connected to form the same island (island) as the gate electrode or gate wiring is connected to the gate electrode or gate wiring. You can call it. Further, for example, a conductive film in a portion where the gate electrode and the gate wiring are connected and formed of a material different from the gate electrode or the gate wiring may be referred to as a gate electrode. You may call it.

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

Note that in the case of calling a gate wiring, a gate line, a gate signal line, a scanning line, a scanning signal line, or the like, the gate of the transistor may 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 simultaneously formed with the wiring 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. It may mean a deposited wiring. Examples include a storage capacitor wiring, a power supply line, a reference potential supply wiring, and the like.

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

However, there are portions (regions, conductive films, wirings, and the like) that also function as source electrodes and function as source wirings. Such a portion (region, conductive film, wiring, or the like) may be called 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, in the case where a part of the source wiring that is arranged to extend and the source region overlap, the portion (region, conductive film, wiring, etc.) functions as the source wiring, but as the source electrode Will also work. Therefore, such a portion (region, conductive film, wiring, or the like) may be called a source electrode or a source wiring.

Note that a portion (region, conductive film, wiring, or the like) that is formed using the same material as the source electrode and forms the same island (island) as the source electrode, or a portion (region) that connects the source electrode and the source electrode , Conductive film, wiring, etc.) may also be referred to as source electrodes. 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 called a source wiring. Such a portion (region, conductive film, wiring, or the like) may not have a function of connecting to another source electrode in a strict sense. However, there are portions (regions, conductive films, wirings, and the like) that are formed of the same material as the source electrode or the source wiring and connected to the source electrode or the source wiring because of specifications in 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 where the source electrode and the source wiring are connected and formed using a material different from that of the source electrode or the source wiring may be referred to as a source electrode. You may call it.

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

In addition, when calling a source wiring, a source line, a source signal line, a data line, a data signal line, etc.
In some cases, the source (drain) of the transistor is not 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 the wiring formed in the same layer as the source (drain) of the transistor and the wiring formed of the same material as the source (drain) of the transistor. Alternatively, it may mean a wiring formed simultaneously with the source (drain) of the transistor. Examples include a storage capacitor wiring, a power supply line, a reference potential supply wiring, and the like.

The drain is the same as the source.

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

Note that a display element means an optical modulation element, a liquid crystal element, a light emitting element, an EL element (an organic EL element, an inorganic EL element or an EL element containing an organic substance and an inorganic substance), an electron-emitting element, an electrophoretic element, a discharge element, and a light reflection element. An element, a light diffraction element, a digital micromirror device (DMD), etc. are said. 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 including a display element. Note that the display device may include a peripheral driver circuit that drives a plurality of pixels. Note that the peripheral driver circuit that drives the plurality of pixels may be formed over 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 or bumps, an IC chip connected by so-called chip on glass (COG), or an IC chip connected by TAB or the like. May be. Note that the display device may include a flexible printed circuit (FPC) to which an IC chip, a resistor element, a capacitor element, an inductor, a transistor, and the like are attached. Note that the display device may include a printed wiring board (PWB) connected via a flexible printed circuit (FPC) or the like to which an IC chip, a resistor element, a capacitor element, an inductor, a transistor, or the like is attached. Note that 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.

Note that the lighting device refers to a device including a backlight unit, a light guide plate, a prism sheet, a diffusion sheet, a reflective sheet, a light source (such as an LED, a cold cathode tube, a hot cathode tube), a cooling device, and the like.

Note that a light-emitting device refers to a device having a light-emitting element or the like. In the case where the display element includes a light-emitting element, the light-emitting device is one example of the display device.

In addition, a reflection apparatus means the apparatus which has a light reflection element, a light diffraction element, a light reflection electrode, etc.

Note that a liquid crystal display device refers to a display device having a liquid crystal element. Liquid crystal display devices include direct view type, projection type, transmission type, reflection type, and transflective type.

Note that a driving device refers to a device having 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 voltage or current to a pixel electrode, or a voltage or current to a light-emitting element A transistor that supplies the voltage is an example of a driving device. Further, a circuit for supplying a signal to the gate signal line (sometimes referred to as a gate driver or a gate line driver circuit) and a circuit for supplying a signal to the source signal line (sometimes referred to as a source driver or source line driver circuit). ) Is an example of a driving device.

Note that a display device, a semiconductor device, a lighting device, a cooling device, a light-emitting device, a reflecting device, a driving device, and the like may overlap 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 driving device.

In addition, when it is explicitly described that B is formed on A or B is formed on A, it is limited that B is formed in direct contact with A. Not. 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.).

Therefore, for example, when it is explicitly described that the layer B is formed on the layer A (or on the layer A), the layer B is formed in direct contact with the layer A. And the case where another layer (for example, layer C or layer D) is formed in direct contact with the layer A, and the layer B is formed in direct contact therewith. Note that another layer (for example, the layer C or the layer D) may be a single layer or a multilayer.

Furthermore, the same applies to the case where B is explicitly described as being formed above A, and is not limited to the direct contact of B on A. This includes the case where another object is interposed in. Therefore, for example, when the layer B is formed above the layer A, the case where the layer B is formed in direct contact with the layer A and the case where another layer is formed in direct contact with the layer A. (For example, the layer C or the layer D) is formed, and the layer B is formed in direct contact therewith. Note that another layer (for example, the layer C or the layer D) may be a single layer or a multilayer.

In addition, when it is explicitly described that B is formed in direct contact with A, it includes a case in which B is formed in direct contact with A. It shall not be included when an object is present.

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

In addition, about what is explicitly described as singular, it is preferable that it is singular.
However, the present invention is not limited to this, and a plurality of them is also possible. Similarly, a plurality that is explicitly described as a plurality is preferably a plurality. However, the present invention is not limited to this, and the number can be singular.

According to the present invention, wide viewing angle display can be realized. In addition, 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 beautiful display. Alternatively, a display device in which display deterioration hardly occurs can be provided. Alternatively, a display device with excellent product life can be provided.

FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. 4A and 4B each illustrate an example of a display device including a pixel of the present invention. 8A and 8B illustrate a structure example of a pixel included in a display device of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 4 is a diagram illustrating an operation method of the display device illustrated in FIG. 3. FIG. 6 illustrates an operation of the pixel illustrated in FIG. 5. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 14 illustrates an example of a pixel layout of a display device according to the present invention. 4A and 4B illustrate a liquid crystal mode of a display device according to the present invention. 4A and 4B illustrate a liquid crystal mode of a display device according to the present invention. 4A and 4B illustrate a liquid crystal mode of a display device according to the present invention. 4A and 4B illustrate a liquid crystal mode of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. The figure which shows an example of the periphery structural member of the display apparatus which concerns on this invention. The figure which shows an example of the periphery structural member of the display apparatus which concerns on this invention. The figure which shows an example of the periphery structural member of the display apparatus which concerns on this invention. The figure which shows an example of the periphery structural member of the display apparatus which concerns on this invention. FIG. 6 shows an example of a panel circuit configuration of a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. 3A and 3B each illustrate an example of a structure of a transistor included in a display device of the present invention. 3A and 3B each illustrate an example of a structure of a transistor included in a display device of the present invention. 3A and 3B each illustrate an example of a structure of a transistor included in a display device of the present invention. 3A and 3B each illustrate an example of a structure of a transistor included in a display device of the present invention. 3A and 3B each illustrate an example of a structure of a transistor included in a display device of the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 6 illustrates a structural example of a display device according to the present invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 16 shows an electronic device using a display device according to the invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 9 illustrates an example of a method for driving a display device according to the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. FIG. 6 illustrates an example of a pixel structure of the present invention. The figure explaining a prior art.

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

(Embodiment 1)
The basic configuration of the pixel of the present invention will be described with reference to 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. , First holding capacitor 131
And a second storage capacitor 132. The pixel includes a signal line 116 and a first scanning line 117.
Are connected to the second scanning line 120 and the Cs line 119. The first liquid crystal element 121
Each of the second liquid crystal elements 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. The pixel electrode of the first liquid crystal element 121 is the second switch 1.
12 and the first resistor 114 are also connected to the pixel electrode of the second liquid crystal element 122. When a 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 is connected to the Cs line 119 via the third switch 113 and the second resistor 115.
Connected with. A connection portion between the second switch 112 and a wiring connecting the pixel electrode of the first liquid crystal element 121 and the first switch 111 is a node 141.

Note that the first switch 111 and the second switch 112 are turned on and off in the first scanning line 11.
7 is controlled by both signals input to the first scanning line 117 and the second scanning line 120, according to the signal input to 7. Here, although the case where each switch is controlled using a scanning line is described, the method of controlling the switch is not limited to this.

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

Note that the liquid crystal element exhibits voltage holding characteristics, but the 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 are used in the pixel illustrated 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 connected to 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 through the second storage capacitor 132. Note that since the voltage holding characteristics of the liquid crystal element depend on the liquid crystal material, impurities mixed in the liquid crystal element, the size of the pixel, and the like, a holding capacitor is particularly provided as shown in FIG. 77 when the voltage holding ratio of the liquid crystal element is high. It is not necessary. For example, the first liquid crystal element 1
If the second liquid crystal element 122 contributes less to the display than the second liquid crystal element 122, the second storage capacitor 132 provided for the second liquid crystal element 122 that contributes less to the display may be omitted.

In FIG. 1, the node 141 is connected to the node 142 through 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 this order. Also good. Further, the node 142 is the second resistor 115 and 1 of the third switch.
13 may be connected to the Cs line 119 sequentially. 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.

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

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

By using the first switch 111, the second switch 112, and the third switch 113, a period in which a potential corresponding to the gray level of the pixel is input to the pixel, that is, a writing period is divided into the first half and the second half. To do. In the first half, the first switch 111 and the second switch 112 except for the third switch 113 are turned on. In the second half, in addition to the first switch 111 and the second switch 112, the third switch 113 is turned on. And As described above, the signal line 116 and the Cs line 119 are electrically disconnected in the first half portion and are electrically connected in the second half portion, so that a video signal can be quickly written to the pixel.

First, in the first half of the writing period, the first scanning line 117 is set to the H level, 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. A potential corresponding to the gray level of the pixel 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 through 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
A potential can be quickly supplied to each of the 22 pixel electrodes.

After that, in the latter half of the writing period, the H level is also input to the second scanning line 120, whereby the third switch 113 is turned on 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. Accordingly, the potential supplied to each of 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 an optimum potential corresponding to the gray level 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. Also, it is determined by the resistance values of the first resistor 114 and the second resistor 115. In other words, the pixel electrode of the second liquid crystal element 122 is supplied with a potential divided by the first resistor 114 and the second resistor 115 according to the gradation of the pixel input from the signal line 116. Will be. Note that the potential corresponding to the gray level 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 is Vsig. Therefore, the potential of the node 142 in the second half of the writing period is Vcs + (Vsi
g−Vcs) × R2 / (R1 + R2).

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

Next, an L level is input to the first scanning 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 disconnected from each other. However, the first storage capacitor 131 stores a potential difference between the potential corresponding to the gray scale input from the signal line 116 and the potential of the Cs line 119, and the second storage capacitor 132 has a resistance-divided potential. A potential difference from the potential of the Cs line 119 is maintained. 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 can be maintained.
The potential divided by the resistance can be maintained also in the two pixel electrodes. Note that 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 manner, the gradation of the pixel is expressed using the potential difference held in the first liquid crystal element 121 and the second liquid crystal element 122, that is, the voltage. First liquid crystal element 121 and second liquid crystal element 12
Since a voltage different from 2 is applied, the liquid crystal included in each liquid crystal element exhibits different alignment. Therefore, the viewing angle characteristic can be improved.

Note that the gray level expressed by the pixel is determined by the orientation of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, and thus the gray level of the pixel supplied from the signal line 116 is the same. 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,
By electrically connecting them in the latter half, 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 corresponding to the gradation of the pixel.
Therefore, it is possible to quickly write a video signal to the pixel.

In addition, 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
1 is controlled using the third scanning line 201, the second switch 112 is controlled using the first scanning line 117, and the third switch 113 is controlled using the first scanning line 117 and the second scanning line 120. It is described. Note that the pixel shown in FIG. 2 can be operated in the same manner as the pixel shown in FIG.

By the way, in the pixel configuration as described above, the voltage applied to the second liquid crystal element 122 is smaller than that of the first liquid crystal element 121. Therefore, if the second resistor 115 is set to be too smaller than the first resistor 114, 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 reduced. 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. Needless to say, the relationship between the resistance values is not limited to this, and it is only necessary that the liquid crystals of the first liquid crystal element 121 and the second liquid crystal element 122 are driven and gradation can be expressed using both liquid crystals. Note that the threshold voltage of the liquid crystal refers to a critical value of a voltage necessary for driving the liquid crystal.

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

  Next, a display device having 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.
The pixel portion 313 includes a plurality of signal lines S1 to Sm arranged extending from the signal line driver circuit 311 in the column direction and a first scanning line G1_ arranged extending from the scanning line driver circuit 312 in the row direction.
1 to G1_n, second scanning lines G2_1 to G2_n, 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 (any one of the signal lines S1 to Sm), a first scanning line G1_i (any one of the scanning lines G1 to Gn), and a second scanning line G2_i. , Cs line C
connected to s_i.

Note that the signal line Sj, the first scanning line G1_i, the second scanning line G2_i, and the Cs line Cs_i are respectively the signal line 116, the first scanning line 117, the second scanning line 120, and the Cs line 11 in FIG.
It corresponds 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
May be electrically connected outside the pixel portion 313 using conductive fine particles, wiring, or the like.

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

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 pixel belonging to the i + 1-th row. In FIG. 17, in order to represent the writing period in each row, the operation of the first switch 111 shown in FIG. Then, the pixel that has completed the writing period in the i-th row expresses a 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 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 in the writing period.

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

The frame inversion driving is a driving method for inverting the polarity of the voltage applied to the liquid crystal element every frame period. Note that one frame period corresponds to a period during which an image for one pixel is displayed, and there is no particular limitation on the period, but at least 1/60 second so that a person viewing the image does not feel flicker. The following is preferable.

Further, it is desirable to shorten the cycle and increase the frequency to reduce image blurring in moving images. Desirably, the period is 1/120 seconds or less (frequency is 120 Hz or more). More desirably, the cycle is 1/180 seconds or less (frequency is 180 Hz or more). When the frame frequency is improved in this way, it is necessary to interpolate the image data when it 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 a display with little afterimage can be performed.

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 lines, and This is a driving method for performing frame inversion on each pixel. On the other hand, the gate line inversion driving means 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 frames are inverted for each pixel. The dot inversion driving is a driving method that inverts the polarity of the voltage applied to the liquid crystal element between adjacent pixels, and is a driving method that combines source line inversion driving and gate line inversion driving.

By the way, the frame inversion drive, the source line inversion drive, the gate line inversion drive,
When dot inversion driving or the like is employed, the potential width required for the video signal written to the signal line is twice that in the case of not performing inversion driving. Therefore, in order to solve this problem, in the case of frame inversion driving or gate line inversion driving, common inversion driving that further inverts the potential of the common electrode may be employed.

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

For example, in the case of performing source line inversion driving, positive and negative video signals, that is, positive and negative video signals are alternately supplied via a signal line every frame period with the potential of the common electrode as the center. 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 that can realize dot inversion driving. In FIG. 4, four pixels are extracted and described, and each pixel has the configuration shown in FIG. In the figure, signal lines 116_1 and 116_2 are connected to the signal line 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, respectively. Signals with different polarities are input to the signal lines 116_1 and 116_2. In accordance with the polarity, even if the pixels belong to the same row, the Cs line is different from the adjacent pixels, that is, Cs.
A potential different from that of the adjacent pixel is supplied as shown in FIG. 80 using the lines 119_1, 419_2 or 119_1, 419_2. Dot inversion driving may be performed by driving as shown in FIG.

Note that a signal for displaying black in the case of normally black, a signal for displaying white in the case of normally white is | 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, Vsig or higher than Vsig (
It is sufficient that a potential of 0) + Vcom or less is supplied to the Cs line. On the other hand, when a negative signal is supplied to the pixel, it is only necessary that a potential of −Vsig (0) + Vcom to Vcom is supplied to the Cs line.

When a positive signal is supplied to the pixel, Vcom + α or more Vsig (0) + V
com or less, -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 signal is supplied to the pixel, V
When the potential of sig (0) + Vcom is a negative polarity signal supplied to the pixel, −Vsig
A potential of (0) + Vcom is preferably supplied.

As described above, the potential of the Cs line is set to Vsig (0 when a positive signal is supplied to the pixel.
) + Vcom and −Vsig (0) + Vcom when a negative polarity signal is supplied, the voltage applied to the second liquid crystal element 122 can be increased, and the second liquid crystal can be increased. The element 122 can be easily controlled.

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

In FIG. 80, Cs in the case where the potential of Vcom is 0 V and a positive 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.

  Note that the inversion driving method is not limited to the above.

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

A pixel 500 illustrated in FIG. 5 includes a first switch 111 and a second switch 112 as in FIG.
, Third switch 113, first resistor 114, second resistor 115, 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 scanning line 517, the Cs line 119, and the first scanning line 517 in 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. . Thus, by sharing the wiring with the next row, the number of wirings can be reduced, and the aperture ratio can be improved.

However, by turning on the third switch 113 in the pixel shown in FIG. 5, 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, ith row, and i + 1th row, and similarly to FIG. 17, the operation of the first switch 111 that can faithfully represent this is described.

In this manner, when the pixel in 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 in the next row becomes the current of the pixel. The voltage varies depending on the gradation. However, since the video signal is written in the pixel of the next row next to the pixel 500, it is particularly problematic to set the period during which the third switch 113 is turned on, that is, the latter half of the writing period to the extent that the display is not affected. Never become.
Of course, this does not occur when the pixel configuration in 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 forms 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 is applied. Can do. That is, it is only necessary to be able to control the current flow, and is not limited to a specific one. For example, a transistor or a diode may be used, or a logic circuit combining these may be used.

As shown in FIG. 6, a second transistor 612 and a third transistor 613 are used for the second switch 112 and the third switch 113 in FIG. 1, respectively, and the on-resistance of these transistors is used. The first resistor 114 and the second resistor 115 may be realized, and these resistors may be omitted. 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 is the first scan line 117 and the second scan line 117. Are composed of two transistors 620 and 621 respectively connected to the scanning line 120.

As described above, the resistance value R2 of the second resistor 115 in FIG.
6 is preferable (R2> R1). Therefore, in the structure in FIG. 6, it is preferable that the on-resistance of the third transistor 613 is larger than the on-resistance of the second transistor 612. 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, W
It is preferable to use transistors 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, a value corresponding to the sum of the channel lengths of the transistors is referred to. However, the relationship is not limited to this. Of course, the configuration of the pixel is not limited to this. For example, as shown in FIG. 81, the second transistor 112, the third switch 113 and the second switch 112 in FIG. With the transistor 613, the resistor may not be omitted.

1 is used as the first switch 111 in FIG. 1, the on-resistance of the first transistor is preferably lower, and the channel width of the first transistor Is W1 and channel length is L1, W1 / L1 is preferably larger. FIG. 83 illustrates the case where the first transistor 8411 is used for the first switch 111 in the structure illustrated in FIG. Note that in the case where 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 that satisfies 1> W2 / L2> W3 / L3. However, the present invention 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 order as shown in FIG. Alternatively, as illustrated 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 this order. In the pixel configuration illustrated in FIG. 7, the third transistor 613 is used.
Since the transistor connected to the node 142 is turned off, the gate capacitance of the transistor can be made smaller than when the transistor is turned on, so that the first half of the writing period is further compared to FIG. As a result, the potential can be supplied to the pixel electrodes of the first liquid crystal element 121 and the second liquid crystal element 122 more quickly.

In order to further increase the on-resistance of the third transistor 613, a multi-gate in which two transistors are connected in series to the transistor 621 constituting the third transistor 613 in FIG. 6 as shown in FIG. A type transistor 821 may be used. Although FIG. 8 shows a 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 transistors when the channel widths W of two transistors connected in series are equal. Therefore, W / L tends to be smaller, and the on-resistance can be increased. Therefore, the on-resistance of the transistor 821 can be easily increased by using a multi-gate transistor. Accordingly, 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.

For example, when the on-resistance of the third transistor 613 is much smaller than that of the second transistor 612, the voltage applied to the second liquid crystal element 122 is higher than that of the second liquid crystal element 122.
In the case where the threshold voltage is lower than the threshold voltage of the liquid crystal included in the transistor, a transistor 1014 diode-connected as a resistor may be provided in series with the third transistor 613 as illustrated in FIG.

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 used.
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. Since the diode has non-linearity and the resistance value becomes larger in a region where the voltage is small, it is particularly effective in such a case. of course,
It is also possible to use a resistor. Note that the potential corresponding to the grayscale input from the signal line 116 is positive here, and an N-channel transistor is used as the transistor 1014, and the drain electrode thereof is connected to 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, a source electrode is connected to the third transistor 613.

As described above, when performing source line inversion, dot inversion driving, or the like, positive and negative image signals centered on the potential of the common electrode, that is, positive and negative image signals are signaled every frame period. It is supplied alternately via lines. 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 a positive image signal is input and when a negative image signal is input. In other words, the potential of the Cs line 119 may be lower when a negative signal is input than when a positive signal is input. Thereby, a voltage can be appropriately supplied to each pixel electrode. Note that the pixel shown in FIG. 10 may be configured as shown in FIG. 11 so that it can handle both positive and negative image signals. The pixel shown in FIG. 11 includes a diode-connected transistor 11 in parallel with the diode-connected transistor 1014 in FIG.
14 is further provided. Note that in the case where 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 between the potentials supplied from 16 is reversed, the second storage capacitor 132 can hold at least a voltage equal to or higher than 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. Even when such a driving method is not performed, the pixel configuration shown in FIG. 11 may be used.

Further, in this specification, the common electrode 118 and the Cs line 119 may be supplied with different potentials or may be supplied with 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.

Although FIGS. 1 to 11 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, there are 3 liquid crystal elements per pixel.
The case where two are included is shown. The pixel illustrated 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 illustrated in FIG. In FIG.
A pixel electrode of the liquid crystal element 1223 is connected to the signal line 116 through 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 the same as the first scanning line 1 in the same manner as the second transistor 612 and the third transistor 613.
17 is connected. The node 1200 is connected to the Cs line 119 via the storage capacitor 1233.
Connected with. Thus, in FIG. 12, the transistor 1214 and the liquid crystal element 1223
In addition, a unit 1201 having a storage capacitor 1233 is 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.

One pixel may have a plurality of the pixel configurations described above. One structural 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 sub-pixel. However, the sub-pixels 1300a and 1300b
The signal line 116, the first scanning line 117, and the second scanning line 120 connected to are commonly used among the sub-pixels. Note that 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 sub-pixels. In this way, the viewing angle can be further improved by utilizing the difference in the alignment of the liquid crystal in each sub-pixel.

Further, as shown in FIG. 13, between the sub-pixels, the signal line 116, the first scanning line 117 and the second scanning line
However, as shown in FIG. 14, only the scanning lines of the first scanning line 117 and the second scanning line 120 are used as sub-pixels 1400a and 1400, respectively.
You may share between b. Further, as shown in FIG. 15, only the signal line 116 is connected to the sub-pixel 1500.
a may be shared among 1500b and the gradation of one pixel may be expressed using these sub-pixels. Note that the wiring used in common among 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 illustrated in FIGS.

The shared wiring need not be a wiring that performs the same function between the sub-pixels. For example,
As shown in FIG. 16, the other subpixel 1 located in the next stage on a scanning line different from the first scanning line 117 among the scanning lines that control the third switch 113 included in one of the subpixels 1600 a.
It is also possible to use the first scanning line 117 included in 600b.

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 to the pixel having the sub-pixel 1600a and the sub-pixel 1600b is completed. Therefore, the first liquid crystal element 121 and the second liquid crystal included in the next row
The voltage applied to the liquid crystal element 122 changes from the voltage corresponding to the gray level of the pixel. However, as in the pixel configuration of FIG. 6, the pixels in the next row are sub-pixels 1600a.
In addition, since a video signal is written next to the pixel having the sub-pixel 1600b, it is particularly problematic to set the period during which the third switch 113 is turned on, that is, the second half of the writing period to a level that does not affect the display. There is no.

13 to 16 show the case where one pixel is configured from sub-pixels having the same configuration, the configuration may be different between sub-pixels. In the above description, the case where the first switch 111, the second switch 112, and the third switch 113 are mainly controlled using the same scanning line is described. However, as shown in FIG. You may control using a scanning line.

As described above, viewing angle characteristics can be improved using the present invention. Further, since the structure can be driven without causing a decrease in contrast, a liquid crystal display device with higher display quality can be provided.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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 is described. 19 includes a first switch 111, a second switch 1712, a third switch 113, and a first switch
Resistor 114, second resistor 115, first liquid crystal element 121, second liquid crystal element 122, first
Storage capacitor 131 and second storage capacitor 132. The pixels are connected to the signal line 116, the first scanning line 117, the second scanning line 120, and the Cs line 119.

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

Also in the pixel shown in FIG. 19, the first switch 111 is similar to the pixel shown in FIG.
The writing period is divided into the first half and the second half using the second switch 1712 and the third switch 113.

Note that only when the first switch 111 is turned on when the H level is input to the first scanning line 117 and the H level is input to both the first scanning line 117 and the second scanning line 120. Next, 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 first scanning line 117 is set to the H level, and the second scanning line 1
The L level is input to 20 to turn on the first switch 111. 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 second half of the writing period, the second switch 1712 and the third switch 113 are turned on in addition to the first switch 111 by inputting the H level to the second scanning line 120 as well. In this way, the signal line 116 and the Cs line 119 that have been electrically disconnected are electrically connected. Accordingly, the potential supplied to the pixel electrode of the first liquid crystal element 121 in the first half of the writing period can be quickly adjusted to an optimum potential corresponding to the gray level of the pixel. In addition, a potential corresponding to the gradation of the pixel is also supplied to the pixel electrode of the second liquid crystal element 122.

In this manner, the gradation of the pixel is expressed using the potential difference held in the first liquid crystal element 121 and the second liquid crystal element 122, that is, the voltage. First liquid crystal element 121 and second liquid crystal element 12
Since a voltage different from 2 is applied, the liquid crystal included in each liquid crystal element exhibits different alignment. Therefore, viewing angle characteristics can be improved. In addition, a video signal can be quickly written to the pixel.

Note that the gray level expressed by the pixel is determined by the orientation of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, and thus the gray level of the pixel supplied from the signal line 116 is the same. The corresponding potential needs to be determined in consideration of these.

Also in FIG. 19, various types of switches 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 only necessary to be able to control the current flow, and is not limited to a specific one. For example, a transistor or a diode may be used, or a logic circuit combining these may be used.

Therefore, as in FIG. 6, as shown in FIG. 20, the second transistor 1722 and the 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 first resistor 114 and the second resistor 115 in FIG. 19 may be realized using resistors, and the resistors may be omitted. Note that the second transistor 1722 and the third transistor 613 include the first scan line 117.
And it needs to be controlled by both signals inputted to the second scanning line 120. 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, 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 and the second switch in FIG.
Although the switch 1712 and the third switch 113 are used, 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 / off by a signal input to the first scan line 117, and the second switch 1712 is turned on / off by the first scan line 117 and the second scan line. 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 the second switch 1712 and the third switch 1733 in FIG. 21, respectively, and the ON resistance of these transistors is used. 21 may realize the first resistor 114 and the second resistor 115 and omit these resistors.

Further, as shown in Embodiment Mode 1, the number of liquid crystal elements included in one pixel is not particularly limited. For example, 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 a switch used for electrically disconnecting the signal line 116 and the Cs line 119 in the first half of the writing period is not limited to the transistor 1722 and the transistor 613, and the signal line 116 and the Cs are connected using a transistor included in the unit. The wire 119 may be electrically disconnected.

As described above, viewing angle characteristics can be improved using the present invention. Further, since the structure can be driven without causing a decrease in contrast, a liquid crystal display device with higher display quality can be provided.
In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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 is described. The pixel shown in FIG. 24 includes a switch 111, a transistor 612, a 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 illustrated in FIG. 24 includes the signal line 116 and the first scanning line 1.
17, a transistor 62 which is connected to the second scanning line 120 and the Cs line 119 and is one transistor constituting the transistor 613 in the pixel of FIG. 6 described in Embodiment Mode 1.
A third storage capacitor 1901 is provided between one electrode of 0 and the node 142. In addition, the code | symbol which points to the same thing is used in common between drawings, and the description is abbreviate | omitted.

The pixel shown in FIG. 24 can 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 the potential corresponding to the gradation to be supplied to the pixel electrode of the second liquid crystal element 122. Therefore, the first liquid crystal element 12
The viewing angle can be further improved by deliberately reducing the response speed of the liquid crystal included in the second liquid crystal element 122 to which the voltage applied from 1 is low. Even in this case, since the gradation represented by the pixel is determined by the orientation 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 can be Determine in consideration of

As shown in FIG. 25, the third storage capacitor 1911 includes a transistor 612 and a node 14.
2 may be provided. In FIG. 25, the pixel can be operated in the same manner as the pixel shown in FIG. Note that it takes time until the pixel electrode of the second liquid crystal element 122 reaches the potential corresponding to the gradation to be supplied, as in the pixel shown in FIG. By using this, the viewing angle can be further improved. In this case, it is necessary to determine the potential supplied from the signal line 116 in consideration of the fact that the voltage applied to the second liquid crystal element 122 is determined by capacitive division with the third storage capacitor 1911. is there.

In the pixel configuration as described above, as in Embodiment Mode 1, the gradation expressed by the pixel is determined by the orientation 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 structure can be driven without causing a decrease in contrast, a liquid crystal display device with higher display quality can be provided.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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, an example of a pixel structure which is different from those in Embodiments 1 to 3 will be described. FIG.
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,
A second storage capacitor 132 and a third storage capacitor 1921 are included. 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 includes transistors in the pixel in FIG. 6 described in Embodiment 1. 1924 and 3rd
The holding capacitor 1921 is provided. The same reference numerals as those in FIG. 6 are used in common throughout the drawings, and the description thereof is omitted.

The third storage capacitor 1921 has a node 1922 as a connection point between the node 142 and 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 1922 and the pixel electrode of the second liquid crystal element 122. The transistor 1924 is provided between the node 1923 and the signal line 116, where a connection location 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. The transistor 1924 is controlled to be turned on / off by a signal input to the first scanning line 117, as in the case of the switch 111, the transistor 612, and the transistor 620.

The pixel shown in FIG. 26 can be operated in the same manner as the pixel shown in FIG. Note that in the pixel illustrated in FIG. 26, a potential is simultaneously supplied from the signal line 116 to the pixel electrodes of the first liquid crystal element 121 and the second liquid crystal element 122 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 corresponding to the gradation of the pixel. Therefore, it is effective for high-speed operation. In addition, in the pixel illustrated in FIG. 26, the gradation expressed by the pixel is determined by the orientation of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, so that the viewing angle is improved. be able to. Note that the on-resistance of the transistor 1924 depends on the switch 1
It is preferably larger than 11 on-resistance.

As described above, viewing angle characteristics can be improved according to the present invention. Further, since the structure can be driven without causing a decrease in contrast, a liquid crystal display device with higher display quality can be provided.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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, an example of a pixel structure which is different from those in Embodiments 1 to 4 will be described. FIG.
The pixel shown in FIG. 11 includes 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. . 27 is connected to the signal line 116, the first scan line 117, the second scan line 120, and the Cs line 119, and the pixel shown in FIG. 3 holding capacitors 1931 are provided.
The same reference numerals as those in FIG. 2 are used in common throughout the drawings, and description thereof is omitted.

The third storage capacitor 1931 has a node 1932 as a connection point between the node 142 and 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 be operated in the same manner as the pixel shown in FIG. Note that by providing the third storage capacitor 1931, it takes time to reach a potential corresponding to a grayscale to be supplied to the pixel electrode of the second liquid crystal element 122. By using this, the viewing angle can be further improved. In addition, the voltage applied to the second liquid crystal element 122 is determined by capacitive division with the third storage capacitor 1931, which is effective when it is desired to apply a small voltage to the second liquid crystal element 122.

Also in the pixel according to this embodiment, the gradation expressed by the pixel is determined by the orientation of the liquid crystal included in each of the first liquid crystal element 121 and the second liquid crystal element 122 in the pixel, so that the viewing angle is improved. be able to.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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 is described. In particular, a pixel structure of a liquid crystal display device will be described.

A pixel structure in which each liquid crystal mode and a transistor are combined will be described with reference to a cross-sectional view 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. As a structure of the transistor, a top gate type, a bottom gate type, or the like can be used. Note that as the bottom-gate transistor, a channel etch type, a channel protection type, or the like can be used.

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

Liquid crystal molecules 2018 shown in FIG. 28 are long and narrow molecules having a major axis and a minor axis. here,
The direction of the liquid crystal molecules 2018 is expressed by the length of the liquid crystal molecules shown in the figure. That is,
The longer expressed liquid crystal molecule 2018 has a major axis direction parallel to the paper surface (cross-sectional direction shown in FIG. 28), and the shorter expressed liquid crystal molecule 2018 has a longer axis direction normal to the paper surface. Suppose that The liquid crystal molecules 2018 illustrated in FIG. 28 are included in the first substrate 2001.
The orientation of the major axis of the liquid crystal molecules is 90 degrees different from that near the second substrate 2016, and the orientation of the major axis of the liquid crystal molecules 2018 located in the middle of these substrates is smooth. It is the direction to connect. That is, the liquid crystal molecules 2018 shown in FIG.
The substrate 2001 and the second substrate 2016 are aligned so as to be twisted by 90 degrees.

Note that a case where a bottom-gate transistor using an amorphous semiconductor is used as a transistor is described. In the case of using a transistor including an amorphous semiconductor, a liquid crystal display device can be manufactured at low cost using a large-area substrate.

The liquid crystal display device has a basic part that displays an image called a liquid crystal panel. A 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 a plurality of substrates. That is, the liquid crystal includes 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 a first substrate 2001 and a second substrate 2016. First substrate 200
1 includes a transistor and a pixel electrode, and the second substrate 2016 includes a light shielding film 201.
4, a color filter 2015, a fourth conductive layer 2013, a spacer 2017, and a second alignment film 2012 are formed.

By providing the light-shielding film 2014, a display device with little light leakage when displaying black can be obtained. Note that the light-blocking film 2014 is not necessarily formed over 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 as in the case of the light-shielding film, so that the manufacturing cost can be reduced and the yield can be improved. However,
In the case where the color filter 2015 is not formed, a display device capable of color display by field sequential driving can be obtained.

Further, spherical spacers may be dispersed instead of the spacers 2017. When the spherical spacers are dispersed, 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 2017 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 little 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. Note that the first insulating film 2002 is not necessarily formed when quartz is used for the substrate 2001.

Next, the first conductive layer 2003 is formed over the first insulating film 2002 by using a photolithography method, a laser direct drawing 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 properties of the transistor.

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

Next, the second conductive layer 2007 is formed by a photolithography method, a laser direct drawing 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,
Etching may be performed using a mask for processing the shape of the second conductive layer 2007 as a mask. The portion of the first semiconductor layer 2005 from which the second semiconductor layer 2006 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 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 simultaneously with the formation of the 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 unevenness of the surface in contact with the liquid crystal, that is, the surface of the third insulating film 2008 affects the alignment of the liquid crystal molecules.

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

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

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

FIG. 29A shows MVA (Multi-domain Vertical Alignnm).
ent) is an example of a cross-sectional view of a pixel when a method and a transistor are combined. FIG.
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.

The characteristics 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 molecules 2118 illustrated in FIG. 29A are the liquid crystal molecules 201 illustrated in FIG.
Similar to 8, it is a long and narrow molecule with a major axis and a minor axis. Therefore, also in FIG. 29A, the direction of the liquid crystal molecules 2118 is expressed by the length of the liquid crystal molecules described in the drawing. That is, FIG.
The liquid crystal molecules 2118 shown in FIG. 9A are aligned so that the direction of the long axis is in the normal direction to the alignment film. In addition, the liquid crystal molecules 2118 in a portion where the alignment control protrusion 2119 is located are aligned radially with the alignment control protrusion 2119 as the center. In this state, a liquid crystal display device with a large viewing angle can be obtained.

Note that a case where a bottom-gate transistor using an amorphous semiconductor is used as a transistor is described. In the case of using a transistor including an amorphous semiconductor, a liquid crystal display device can be manufactured at low cost using a large-area substrate.

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

By providing the light-blocking film 2114, a display device with little light leakage when displaying black can be obtained. Note that the light-blocking film 2114 is not necessarily formed over the second substrate 2116. When the light-blocking 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 is not necessarily 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 the manufacturing cost can be reduced and the yield can be improved. However,
In the case where the color filter 2115 is not formed, a display device capable of performing color display by field sequential driving can be obtained.

Further, spherical spacers may be dispersed instead of the spacers 2117. When the spherical spacers are dispersed, 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 little display unevenness can be obtained.

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. Note that the first insulating film 2102 is not necessarily formed when quartz is used for the substrate 2101.

Next, a first conductive layer 2103 is formed over the first insulating film 2102 by using a photolithography method, a laser direct drawing method, an ink jet method, or the like.

Next, a second insulating film 2104 is formed on 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, a first semiconductor layer 2105 and a 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 drawing 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. Further, the mask may be etched using a mask for processing the shape of the second conductive layer 2107. The first semiconductor layer 2105 from which the second semiconductor layer 2106 has been 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 a contact hole is formed in the third insulating film 2108.

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

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

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

Note that in the MVA mode, the fourth conductive layer 2113 is formed over the entire surface of the second substrate 2116. In addition, an alignment control protrusion 2119 is formed in contact with the fourth conductive layer 2113. The shape of the orientation control protrusion 2119 is preferably a shape having a smooth curved surface. By doing so, alignment defects of the liquid crystal molecules 2118 due to the alignment control protrusions 2119 are reduced. In addition, since the alignment film formed on the alignment control protrusion 2119 can be prevented from being disconnected, defects in the alignment film due to the disconnection can be reduced.

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

Features of the pixel structure illustrated in FIG. 29B are described. Liquid crystal molecule 2 shown in FIG.
148 is the same as the liquid crystal molecule 2018 shown in FIG. 28, and the liquid crystal molecule 2 is also shown in FIG.
The direction of 148 is expressed by the length of the liquid crystal molecules described in the figure. Therefore, FIG. 29 (B
The liquid crystal molecules 2148 shown in (1) are aligned so that the direction of the major axis is in the normal direction to the alignment film. In addition, the liquid crystal molecules 2148 present around the electrode notch 2149 where the fourth conductive layer 2143 is not provided are aligned radially around the boundary between the electrode notch 2149 and the fourth conductive layer 2143. In this state, a liquid crystal display device with a large viewing angle can be obtained.

Note that a case where a bottom-gate transistor using an amorphous semiconductor is used as a transistor is described. In the case of using a transistor including an amorphous semiconductor, a liquid crystal display device can be manufactured at low cost using a large-area substrate.

In FIG. 29B, two substrates between which the liquid crystal 2141 is sandwiched 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-shielding film 2144, a color filter 2145,
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 little light leakage when displaying black can be obtained. Note that the light-blocking film 2144 is not necessarily formed over the second substrate 2146. In the case where the light-blocking 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 over 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 the manufacturing cost can be reduced and the yield can be improved. However,
In the case where the color filter 2145 is not formed, a display device capable of performing color display by field sequential driving can be obtained.

Further, spherical spacers may be dispersed instead of the spacers 2147. When the spherical spacers are dispersed, 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 2147 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 little display unevenness can be obtained.

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 for the substrate 2131, the first insulating film 2132 is not necessarily formed.

Next, the first conductive layer 2133 is formed over the first insulating film 2132 by using a photolithography method, a laser direct drawing 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, a first semiconductor layer 2135 and a second semiconductor layer 2136 are formed. Note that the first semiconductor layer 2135 and the second semiconductor layer 2136 are successively formed, and these shapes are processed at the same time.

Next, the second conductive layer 2137 is formed by a photolithography method, a laser direct drawing 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 the second conductive layer 2137 may be formed using a transparent material or a reflective material.

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,
Etching may be performed using a mask for processing the shape of the second conductive layer 2137 as the mask. Then, a portion of the first semiconductor layer 2135 from which the second semiconductor layer 2136 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 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 a contact hole is formed in the third insulating film 2138.

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

Next, a first alignment film 2140 is formed. Note that after the first alignment film 2140 is formed, rubbing treatment may be performed in order to control 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 are formed are attached to each other with a sealant with a gap of several micrometers. Then, a liquid crystal material is injected between the two substrates.

Note that in the PVA method, the fourth conductive layer 2143 is subjected to patterning, so that an electrode notch 2149 is formed. The shape of the electrode notch 2149 is not particularly limited, but is preferably a shape in which a plurality of rectangles having different directions are combined. By doing this,
Since a plurality of regions having different orientations can be formed, a liquid crystal display device having a large viewing angle can be obtained. Note that the shape of the fourth conductive layer 2143 at the boundary between the electrode notch 2149 and the fourth conductive layer 2143 preferably has a smooth slope with respect to the bottom. By doing so, alignment defects of the liquid crystal molecules 2148 close to the inclined surface are reduced. In addition, since the alignment film formed over the fourth conductive layer 2143 can be prevented from being disconnected, defects in the alignment film due to the disconnection can be reduced.

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. By applying the pixel structure shown in FIG. 30A to the liquid crystal display device of the present invention, the viewing angle can be further increased.

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

Note that a case where a bottom-gate transistor using an amorphous semiconductor is used as a transistor is described. In the case of using a transistor including an amorphous semiconductor, a liquid crystal display device can be manufactured at low cost using a large-area substrate.

In FIG. 30A, two substrates between which the liquid crystal 2211 is sandwiched correspond to a first substrate 2201 and a second substrate 2216. Note that transistors and pixel electrodes are formed over the first substrate 2201, and a light shielding 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-blocking film 2214, a display device with little light leakage when displaying black can be obtained. Note that the light-blocking film 2214 is not necessarily formed over the second substrate 2216. In the case where the light-blocking 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 is not necessarily formed on the second substrate 2216. Even in the case where the color filter 2215 is not formed, the number of steps can be reduced as in the case of the light-shielding film, so that the manufacturing cost can be reduced and the yield can be improved. However,
In the case where the color filter 2215 is not formed, a display device that can perform color display by field sequential driving can be obtained.

Further, spherical spacers may be dispersed instead of the spacers 2217. When the spherical spacers are dispersed, 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 little display unevenness can be obtained.

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. Note that in the case where quartz is used for the substrate 2201, the first insulating film 2202 is not necessarily formed.

Next, a first conductive layer 2203 is formed over the first insulating film 2202 by using a photolithography method, a laser direct drawing 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, a first semiconductor layer 2205 and a second semiconductor layer 2206 are formed. Note that the first semiconductor layer 2205 and the second semiconductor layer 2206 are formed successively, and their shapes are processed at the same time.

Next, the second conductive layer 2207 is formed by a photolithography method, a laser direct drawing 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 the second conductive layer 2207 may be formed using a transparent material or a reflective material.

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,
Etching may be performed using a mask for processing the shape of the second conductive layer 2207 as the mask. The portion of the first semiconductor layer 2205 from which the second semiconductor layer 2206 has been 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 a contact hole is formed in the third insulating film 2208.

Next, the third conductive layer 2209 is formed by a photolithography method, a laser direct drawing method, an inkjet method, or the like. Here, the shape of the third conductive layer 2209 is two comb teeth that are meshed with each other. One comb-like electrode is electrically connected to one of the source electrode and the drain electrode of the transistor, and the other comb-like 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, a first alignment film 2210 is formed. Note that after the first alignment film 2210 is formed, rubbing treatment may be performed in order to control 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 manufactured are bonded to each other with a sealant with a gap of several micrometers. Then, a 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 an FFS (Fringe Field Switching) method and a transistor are combined. By applying the pixel structure shown in FIG. 30B to the liquid crystal display device of the present invention, the viewing angle can be further increased.

Features of the pixel structure illustrated in FIG. Liquid crystal molecule 2 shown in FIG.
Similarly to the liquid crystal molecules 2018 shown in FIG. 248 and FIG. 28, the liquid crystal molecules 21 in FIG.
The direction of 48 is expressed by the length of the liquid crystal molecules described in the figure. Therefore, FIG. 30 (B)
The liquid crystal molecules 2248 shown in FIG. 6 are aligned so that the direction of the major axis is always in the horizontal direction with respect to the substrate. In FIG. 30B, the liquid crystal molecules 2248 are aligned in a state where no electric field is generated in the region where the liquid crystal 2241 is present. When an electric field is applied to the liquid crystal molecules 2248, the orientation of the major axis is shown. Rotate in a horizontal plane while always maintaining a horizontal orientation with respect to the substrate. In this state, a liquid crystal display device with a large viewing angle can be obtained.

Note that a case where a bottom-gate transistor using an amorphous semiconductor is used as a transistor is described. In the case of using a transistor including an amorphous semiconductor, a liquid crystal display device can be manufactured at low cost using a large-area substrate.

In FIG. 30B, two substrates sandwiching the liquid crystal 2241 correspond to the first substrate 2231 and the second substrate 2246. Note that transistors and pixel electrodes are formed over the first substrate 2241, and a light shielding film 2244, a color filter 2245, and the like are formed over the second substrate 2246.
A spacer 2247 and a second alignment film 2242 are formed.

By providing the light-blocking film 2244, a display device with little light leakage when displaying black can be obtained. Note that the light-blocking film 2244 is not necessarily formed over the second substrate 2246. In the case where the light-blocking 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 is not necessarily formed on the second substrate 2246. Even in the case where 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 the manufacturing cost can be reduced and the yield can be improved. However,
In the case where the color filter 2245 is not formed, a display device capable of performing color display by field sequential driving can be obtained.

Further, spherical spacers may be dispersed instead of the spacers 2247. When the spherical spacers are dispersed, 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 easily made constant, and a display device with little display unevenness can be obtained.

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,
In the case where quartz is used for the substrate 2231, the first insulating film 2232 is not necessarily formed.

Next, the first conductive layer 2233 is formed over the first insulating film 2232 by using a photolithography method, a laser direct drawing 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, a first semiconductor layer 2235 and a second semiconductor layer 2236 are formed. Note that the first semiconductor layer 2235 and the second semiconductor layer 2236 are continuously formed, and these shapes are processed at the same time.

Next, the second conductive layer 2237 is formed by a photolithography method, a laser direct drawing 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 as the second conductive layer 2237, 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 2236 is etched using the second conductive layer 2237 as a mask. Also,
Etching may be performed using a mask for processing the shape of the second conductive layer 2237 as the mask. The portion of the first semiconductor layer 2235 from which the second semiconductor layer 2236 has been 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 contact holes are selectively formed in the third insulating film 2238.

Next, the third conductive layer 2239 is formed by a photolithography method, a laser direct drawing 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 drawing method, an inkjet method, or the like. Here, the fourth conductive layer 2243 has a comb shape.

Next, a first alignment film 2240 is formed. Note that after the first alignment film 2240 is formed, rubbing treatment may be performed in order to control 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 manufactured are bonded to each other with a gap of several micrometers by a sealing material, 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. These insulating films are silicon oxide films,
An insulating film having a stacked structure in which two or more of a silicon nitride film, a silicon oxynitride film (SiOxNy), or the like is 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. As the first conductive layer 2233 of 30 (B), a conductive material such as Mo, Ti, Al, Nd, or Cr can be used. These conductive layers are made of conductive materials such as Mo, Ti, Al, Nd, and Cr.
A laminated structure in which two or more are combined can also be used.

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 second insulating film 2234 of 30 (B), a thermal oxide film, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like can be used. Alternatively, 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 a silicon oxide film is preferable in a portion in contact with the semiconductor layer. This is because the trap level at the interface with the semiconductor layer is reduced by using the silicon oxide film. Note that a silicon nitride film is preferable in a portion in contact with Mo. 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 FIG.
), 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 FIG.
), The second semiconductor layer 2206 in FIG. 30A, and the second semiconductor layer 2236 in FIG. 30B can be formed using silicon containing phosphorus or the like.

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. 29B, and 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. Conductive layer 224 of
3 materials having transparency, indium tin oxide (ITO) film in which tin oxide is mixed with indium oxide, indium tin silicon oxide (ITSO) film in which indium tin oxide (ITO) is mixed with silicon oxide, Indium zinc oxide in which zinc oxide is mixed with indium oxide (
IZO) film, zinc oxide film, tin oxide film, or the like can be used. IZO is I
It can be formed by sputtering using a target in which 2 to 20 wt% zinc oxide (ZnO) is mixed with TO.

28, the second conductive layer 2007 and the third conductive layer 2009, 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 for 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 structure in which Al is sandwiched between metals such as Ti, Mo, Ta, Cr, and W may be employed.

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 in FIG. 30A, the third insulating film 2238, and the fourth insulating film 2249 in FIG. 30B, an inorganic material (silicon oxide, silicon nitride, silicon oxynitride, or the like) or a low An organic compound material having a dielectric constant (photosensitive or non-photosensitive organic resin material) can be used. Alternatively, a material containing siloxane can be used. Siloxane is silicon (Si).
It is a material in which a skeleton structure is formed by a bond of oxygen 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 a substituent.

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

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

As the liquid crystal mode, TN (Twisted Nematic) mode, IPS (
In-Plane-Switching mode, FFS (Fringe Field)
Switching mode, MVA (Multi-domain Vertical)
Alignment mode, PVA (Patterned Vertical Ali)
gmnent), ASM (Axial Symmetric Aligned Mi)
cro-cell) mode, OCB (Optical Compensated Bir)
efficiency mode, FLC (Ferroelectric Liquid)
Crystal) mode, AFLC (Antiferroelectric 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 a structure of the transistor. As the bottom-gate transistor, a channel etch type, a channel protection type, or the like can be used.

FIG. 31 shows an example of a top view of a pixel when a TN mode and a transistor are combined.

A pixel illustrated in FIG. 31 includes a first transistor 2304, a second transistor 2305, a third transistor including 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, and is connected to the first scan line 2300, the second scan line 2301, the signal line 2302, and the Cs line 2311. Note that an equivalent circuit diagram of the pixel configuration illustrated in FIG. 31 is the same as that of FIG. 83, and thus detailed description thereof is omitted.

In FIG. 31, the pixel electrode constituting the first liquid crystal capacitor corresponds to the pixel electrode 2307, and the pixel electrode constituting 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 includes a capacitor line 2312, a semiconductor layer 2310 connected to the pixel electrode 2308, and an insulating film provided therebetween. In addition,
A capacitor line 2312 included in the first storage capacitor and the second storage capacitor is connected to the transistor 2304.
2305 and 2320, a first scan line 2300 including a gate electrode constituting the transistor 2321, a second scan line 2301 and a Cs line 2301 including a gate electrode constituting the transistor 2321, and the semiconductor layers 2309 and 2310 are transistors 2304 and 2305, 2320 and 2321 are formed in the same process as the semiconductor layer including the source region, the drain region, and the channel formation region. In addition, a film manufactured in the same process as the gate insulating films included in the transistors 2304, 2305, 2320, and 2321 can be used for the insulating films included in the first storage capacitor and the second storage capacitor. .

As shown in FIG. 31, a liquid crystal display device having excellent viewing angle characteristics can be obtained by using two liquid crystal capacitors having different alignment states. Note that 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 providing 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 whose mobility is lower than that of the crystalline semiconductor layer is used for the semiconductor layer of the transistor constituting the pixel.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (may be a part) described in each drawing of this embodiment are applied to and combined with the contents (may be a part) described in the drawings of another embodiment and examples. Or can be freely replaced. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each embodiment with a portion of another embodiment and an example.

Note that in this embodiment, the contents described in other embodiments and examples (may be a part)
Example when embodied, example when slightly modified, example when partially changed, example when improved, example when described in detail, example when applied, example with 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 will be described with reference to cross-sectional views.

32A and 32B are schematic views of cross sections of the TN mode.

A liquid crystal layer 3300 is sandwiched between a first substrate 3301 and a second substrate 3302 which are arranged to face each other. A first electrode 3305 is formed on the top surface of the first substrate 3301. A second electrode 3306 is formed on the top surface of the second substrate 3302. A first polarizing plate 3303 is disposed on the opposite side of the first substrate 3301 from the liquid crystal layer. Second
A second polarizing plate 3304 is provided 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 disposed on the upper surface of the first substrate 3301. The second polarizing plate 3304 may be disposed 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 (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (semi-transmissive type).

FIG. 32A is a schematic view 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 mode). Since the liquid crystal molecules are arranged 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 so as to be crossed Nicols, light from the backlight cannot pass through the substrate. Therefore, black display is performed.

FIG. 32B is a schematic view 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
Since the light is rotated toward 306, the light from the backlight is affected by the birefringence of the liquid crystal molecules. 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 a 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 orientation can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, a predetermined video display can be performed.

The liquid crystal display device having the structure illustrated 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 cross sections of 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 there is no electric field.

A liquid crystal layer 3400 is sandwiched between a first substrate 3401 and a second substrate 3402 which are arranged to face each other. A first electrode 3405 is formed on the top surface of the first substrate 3401. A second electrode 3406 is formed on the top surface of the second substrate 3402. A first polarizing plate 3403 is provided on the opposite side of the first substrate 3401 to the liquid crystal layer. Second
A second polarizing plate 3404 is disposed 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 disposed on the top surface of the first substrate 3401. The second polarizing plate 3404 may be disposed 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 (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (semi-transmissive type).

FIG. 33A is a schematic view of a cross section in the case where voltage is applied to the first electrode 3405 and the second electrode 3406 (referred to as a vertical electric field mode). 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. 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 arranged vertically, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. 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 a 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 orientation can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, a predetermined video display can be performed.

The liquid crystal display device having the structure illustrated 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.

As the liquid crystal material used for the VA mode, a known material may be used.

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

A liquid crystal layer 3410 is sandwiched between a first substrate 3411 and a second substrate 3412 which are arranged to face each other. A first electrode 3415 is formed on the top surface of the first substrate 3411. A second electrode 3416 is formed on the top surface of the second substrate 3412. A first protrusion 3417 is formed over the first electrode 3415 for alignment control. A second protrusion 3418 is formed over the second electrode 3416 for alignment control. A first polarizing plate 3413 is provided on the side of the first substrate 3411 opposite to the liquid crystal layer. Second substrate 3
A second polarizing plate 3414 is disposed on the side opposite to 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 disposed on the top surface of the first substrate 3411. The second polarizing plate 3414 may be disposed on the upper surface of the second substrate 3412.

It is only necessary that at least one (or both) of the first electrode 3415 and the second electrode 3416 have a light-transmitting property (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (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 mode). Light from the backlight is affected by the birefringence of the 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. Further, the liquid crystal molecules contain the first protrusion 3417 and the second protrusion 341.
8, 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 arranged 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 so as to be crossed Nicols, light from the backlight does not pass through the substrate. Therefore, black display is performed. This is a so-called normally black mode.

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

A liquid crystal display device having the structure illustrated 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.

As the liquid crystal material used for the MVA mode, a known material may be used.

34A and 34B are schematic views of OCB mode cross sections. In the OCB mode, the alignment of the liquid crystal molecules forms an optically compensated state in the liquid crystal layer, and thus the viewing angle dependency is small. This state of the 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 to face each other. A first electrode 3505 is formed on the top surface of the first substrate 3501. A second electrode 3506 is formed on the top surface of the second substrate 3502. On the opposite side of the first substrate 3501 from the liquid crystal layer, a first polarizing plate 3503 is provided. Second
A second polarizing plate 336 is disposed 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 disposed on the top surface of the first substrate 3501. The second polarizing plate 336 may be disposed on the upper surface of the second substrate 3502.

It is only necessary that at least one (or both) of the first electrode 3505 and the second electrode 3506 has a light-transmitting property (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (semi-transmissive type).

FIG. 34A is a schematic view 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 mode). Since the liquid crystal molecules are arranged vertically, the light from the backlight is not affected by the birefringence of the liquid crystal molecules. Then, the first polarizing plate 3503
And the second polarizing plate 336 are arranged so as to be crossed Nicols, so that 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 a 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 crossed Nicols, light from the backlight passes through the substrate. Therefore, white display is performed. This is a so-called normally white mode.

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

The liquid crystal display device having the structure illustrated 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 material may be used as the liquid crystal material used in the OCB mode.

34C and 34D are schematic views of cross sections 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 to face each other. A first electrode 3515 is formed on the top surface of the first substrate 3511. A second electrode 3516 is formed on the top 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 disposed 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 disposed on the top surface of the first substrate 3511. The second polarizing plate 3514 may be disposed 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 have a light-transmitting property (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (semi-transmissive type).

FIG. 34C is a schematic view of a cross section in the case where voltage is applied to the first electrode 3515 and the second electrode 3516 (referred to as a vertical electric field mode). Since the liquid crystal molecules are arranged side by side in a direction shifted from the rubbing direction, the light from the backlight is affected by the birefringence of the liquid crystal molecules. 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. And the 1st polarizing plate 3
Since the light source 513 and the second polarizing plate 3514 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 a so-called normally black mode.

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

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 in the FLC mode or AFLC mode, a known material may be used.

FIGS. 35A and 35B are schematic views of cross sections of 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 electrode adopts a horizontal electric field method provided only on one substrate side.

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 side of the first substrate 3601 opposite to the liquid crystal layer. A second polarizing plate 3604 is disposed 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 disposed on the top surface of the first substrate 3601. The second polarizing plate 3604 may be disposed on the upper surface of the second substrate 3602.

It is only necessary that at least one (or both) of the first electrode 3605 and the second electrode 3606 have a light-transmitting property (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (semi-transmissive type).

FIG. 35A is a schematic view 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 crossed Nicols, 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. And the 1st polarizing plate 3
Since 603 and the second polarizing plate 3604 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 a so-called normally black mode.

By controlling voltages applied to the first electrode 3605 and the second electrode 3606, the state of the liquid crystal molecules, that is, the orientation can be controlled. Therefore, since the light from the backlight can be controlled by the liquid crystal molecules, a predetermined video display can be performed.

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

As the liquid crystal material used for the IPS mode, a known material may be used.

FIGS. 35C and 35D are schematic views of cross sections of 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 the electrode adopts a lateral electric field method provided only on one substrate side.

A liquid crystal layer 3610 is sandwiched between a first substrate 3611 and a second substrate 3612 which are arranged to face each other. A second electrode 3616 is formed on the top surface of the first substrate 3611. An insulating film 3617 is formed on the top 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 3613
The polarizing plate 3614 is arranged so as to be crossed Nicols.

The first polarizing plate 3613 may be disposed on the top surface of the first substrate 3611. The second polarizing plate 3614 may be disposed 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 (a transmission type or a reflection type). Or both electrodes may have translucency and a part of one electrode may have reflectivity (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. 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. And the 1st polarizing plate 3
Since 613 and the second polarizing plate 3614 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 a so-called normally black mode.

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

The liquid crystal display device having the structure illustrated 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.

As the liquid crystal material used for the FFS mode, a known material may be used.

Next, various liquid crystal modes will be described with reference to top views.

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

36 shows a first electrode 3701, a second electrode (3702a, 3702b, 3702c),
And the protrusion 3703 is shown. The first electrode 3701 is formed over the entire surface of the counter substrate. The second electrodes (3702a, 3702b, 3702c are formed so that the shape is a dogleg shape.
) Is formed. The second electrode (3702a, 3702b, 3702c) is formed over the first electrode 3701 so that the shape corresponds to the second electrode (3702a, 3702b, 3702c).
) Is formed.

The opening of the second electrode (3702a, 3702b, 3702c) functions like a protrusion.

When voltage is applied to the first electrode 3701 and the second electrode (3702a, 3702b, 3702c) (referred to as a vertical electric field mode), liquid crystal molecules are converted to the second electrode (3702a, 3702b,
3702c) and the protrusions 3703 are tilted and arranged. Therefore, the viewing angle can be improved. Note that when the pair of polarizing plates are arranged so as to be in crossed Nicols, 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, and 3702c), liquid crystal molecules are aligned vertically. When the pair of polarizing plates are arranged to be crossed Nicols, the light from the backlight does not pass through the panel,
Black display is performed. This is a so-called normally black mode.

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

As the liquid crystal material used for the MVA mode, a known material may be used.

FIGS. 37A, 37B, 37C, and 37D are 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 electrode adopts a horizontal electric field method provided only on one substrate side.

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

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

FIG. 37B illustrates the first electrode 3811 and the second electrode 3812. The first electrode 3811 and the second electrode 3812 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 have a comb-like shape and are partially overlapped with each other.

FIG. 37D illustrates a first electrode 3841 and a second electrode 3842. The first electrode 3841 and the second electrode 3842 are comb-like and have a shape in which 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 so as to be in crossed Nicols, 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
When no voltage is applied to 812, 3822, 3832), the liquid crystal molecules are arranged side by side along the rubbing direction. When the pair of polarizing plates are arranged so as to be crossed Nicols, light from the backlight does not pass through the substrate, so that black display is performed. It is a so-called normally black mode.

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

As the liquid crystal material used for the IPS mode, a known material may be used.

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 electrode adopts a lateral electric field method provided only on one substrate side.

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 a first electrode 3901 and a second electrode 3902. The first electrode 3901 has a bent dogleg shape. The second electrode 3902 may not be patterned.

FIG. 38B illustrates a first electrode 3911 and a second electrode 3912. The first electrode 3911 has a concentric shape. The second electrode 3912 may not be patterned.

FIG. 38C illustrates a first electrode 3931 and a second electrode 3932. The first electrode 3931 has a comb-like shape so that the electrodes are engaged with each other. The second electrode 3932 may not be patterned.

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

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

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

As the liquid crystal material used for the IPS mode, a known material may be used.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (may be a part) described in each drawing of this embodiment are applied to and combined with the contents (may be a part) described in the drawings of another embodiment and examples. Or can be freely replaced. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each embodiment with a portion of another embodiment and an example.

Note that in this embodiment, the contents described in other embodiments and examples (may be a part)
Example when embodied, example when slightly modified, example when partially changed, example when improved, example when described in detail, example when applied, example with 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.
7 shows an example of a liquid crystal display device. The edge light type is a method in which a light source is arranged at the end of the backlight unit and light emitted from 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,
The lamp reflector 2605 and the light source 2606 are included.

The light source 2606 has a function of emitting light as necessary. For example, as the light source 2606, a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL, an organic EL, or the like 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 light from the light source 2603 and guiding the light to the entire surface. The diffusion plate 2602 has a function of reducing brightness unevenness. The reflector 2604 is
The light leaking from the light guide plate 2603 in the opposite direction from the liquid crystal panel 2603 is reflected and reused.

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

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

A backlight unit 2701 shown 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 to efficiently reflect light from the cold cathode fluorescent lamp 2703. Such a structure is often used for a large display device.

A backlight unit 2711 illustrated 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 light from the light emitting diode 2713.

Since the light emission intensity of the light emitting diode is strong, the structure using the light emitting diode is suitable for a large display device. Further, since the light emitting diode is excellent in color reproducibility, an image faithful to input image information can be displayed. Further, since the light emitting diode is small, the arrangement area can be reduced. Therefore, it is possible to reduce the frame of the display device.

Note that in the case where the light-emitting diode is mounted on a large display device, the light-emitting diode can be disposed on the back surface of the substrate. The light emitting diodes maintain a predetermined interval, and the light emitting diodes of each color are arranged in order.

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

Since the luminance of the light emitting diode is high, a configuration using light emitting diodes of RGB colors as a light source is suitable for a large display device. Further, since the light emitting diode is excellent in color reproducibility, an image faithful to input image information can be displayed. Further, since the light emitting diode is small, the arrangement area can be reduced. Therefore, it is possible to reduce the frame of the display device.

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

A light emitting diode emitting white light and a light emitting diode (LED) 2723 of each color of RGB.
A light emitting diode (LED) 2724 and a light emitting diode (LED) 2725 can be combined.

Note that in the case where the light-emitting diode is mounted on a large display device, the light-emitting diode can be disposed on the back surface of the substrate. Further, each of the light emitting diodes maintains a predetermined interval, and the light emitting diodes of the respective colors are arranged in order. With such an arrangement, color reproducibility can be improved.

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

Since the light emission intensity of the light emitting diode is high, a configuration using light emitting diodes of RGB colors as a light source is suitable for a large display device. Further, since the light emitting diode is excellent in color reproducibility, an image faithful to input image information can be displayed. Further, since the light emitting diode is small, the arrangement area can be reduced. Therefore, it is possible to reduce the frame of the display device.

Note that color display can be performed by sequentially lighting the RGB light emitting diodes according to time.

Note that a light emitting diode emitting 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.

Note that in the case where the light-emitting diode is mounted on a large display device, the light-emitting diode can be disposed on the back surface of the substrate. Each of the light emitting diodes maintains a predetermined interval, and the light emitting diodes of each color are arranged in order. 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. The direct type is a method in which a light source is disposed directly under a light emitting surface, and light emitted from the light source is emitted from the entire light emitting surface. The direct type backlight unit can efficiently use the amount of emitted light.

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

The light source 2804 has a function of emitting light as necessary. For example, as the light source 2805, a cold cathode tube, a hot cathode tube, a light emitting diode, an inorganic EL, an organic EL, or the like is used. The lamp reflector 2803 efficiently emits light from the light source 2804 and the light-shielding plate 2801.
802 has a function of leading to 802. The light shielding plate 2802 has a function of reducing unevenness in brightness by increasing the light shielding as the light is stronger in accordance with the arrangement of the light sources 2804. Diffusion plate 2801
Has a function of further reducing unevenness in brightness.

Note that a control circuit for adjusting the luminance of the light source 2804 is connected to the backlight unit 2800. With this control circuit, the luminance of the light source 2804 can be adjusted.

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 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 RGB light sources 2814a (R), 2814b (G), and 2814c (B) 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, an organic EL, or the like is used. The lamp reflector 2813 has a function of efficiently guiding light emitted from the light source 2814 to the diffusion plate 2811 and the light shielding plate 2812. The light shielding plate 2812 is
As the light intensity is increased in accordance with the arrangement of the light source 2814, the light shielding is increased so that the lightness unevenness is reduced. The diffusion plate 2811 further has a function of reducing brightness unevenness.

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

FIG. 42 is a diagram illustrating an example of a 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 making light only in a certain vibration direction (linearly polarized light). Specifically, the PVA polarizing film 2903 includes molecules (polarizers) whose electron densities are greatly different from each other vertically and horizontally. With the PVA polarizing film 2903 in which the directions of molecules having greatly different electron densities in the vertical and horizontal directions are aligned, it becomes possible to obtain linearly polarized light.

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

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

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

The other substrate film (substrate film 2902) is provided with a protective film 2901.

Note that a hard coat scattering layer (antiglare layer) may be provided on the surface of the polarizing film 2900. The hard coat scattering layer has fine irregularities formed on the surface by AG treatment, and has an antiglare function for scattering external light, so that 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 indexes may be formed on the surface of the polarizing film 2900 (also referred to as anti-reflection treatment or AR treatment). The multilayered optical thin film layer having a plurality of refractive indexes can reduce the reflectance of the surface due to the light interference effect.

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

As shown in FIG. 43A, the signal line 3012 is connected to the signal line driver circuit 300 in the pixel portion 3005.
3 is extended and arranged. A scanning line 3010 is extended from the scanning line driver circuit 3004. A plurality of pixels are arranged in a matrix in the intersection region between the signal line 3012 and the scanning line 3010. Note that each of the plurality of pixels includes a switching element, and the details of the pixel portion 3005 are described in the above embodiment and thus are omitted here.

43A, the driver circuit portion 3008 includes a control circuit 3002 and a signal line driver circuit 30.
03 and a scanning line driver circuit 3004. A video signal 3001 is input to the control circuit 3002. The control circuit 3002 responds to the control signal 3001 with the signal line driving circuit 30.
03 and the scanning line driving circuit 3004 are controlled. Therefore, the control circuit 3002 inputs control signals to the signal line driver circuit 3003 and the scan line driver circuit 3004. In response to 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, a switching element included in the pixel is selected according to the scanning signal, and a video signal is input to the pixel electrode of the pixel.

Note that the control circuit 3002 also controls the power supply 3007 in accordance with the control signal 3001. Note that the power source 3007 has means for supplying power to the lighting means 3006. Illumination 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 for the illumination means 3006. The front light is a plate-like light unit that is mounted on the front side of the pixel portion and is configured by a light emitter and a light guide that illuminate the whole. Such illumination means can illuminate the pixel portion evenly with low power consumption.

The scan line driver circuit 3004 includes, for example, a shift register 3041 as illustrated in FIG.
A circuit functioning as a level shifter 3042 and a buffer 3043 is included. Note that a signal such as a gate start pulse (GSP) or a gate clock signal (GCK) is input from the control circuit 2902 to the shift register 3041.

As shown in FIG. 43C, the signal line driver circuit 3003 includes circuits that function as a shift register 3031, a first latch 3032, a second latch 3033, a level shifter 3034, and a buffer 3035. A 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.
2 is input with data (DATA) such as a video signal. A latch (LAT) signal can be temporarily stored in the second latch 3033 and is 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 can be dispensed with.

Note that in this embodiment, a known liquid crystal panel can be used. For example, a configuration in which a liquid crystal layer is sealed between two substrates can be used as the liquid crystal panel.
On one substrate, a transistor, a capacitor, a pixel electrode, an alignment film, or the like is formed. A polarizing plate, a phase difference plate, or a prism sheet may be disposed on the side opposite to the upper surface of the substrate. On the other substrate, a color filter, a black matrix, a counter electrode, an alignment film, or the like is formed. Note that a polarizing plate or a retardation plate may be disposed on the side opposite to the upper surface of the other substrate. Note that 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 slits (lattices) on the upper surface side of one substrate or the opposite side thereof.

In addition, it is possible to arrange | position a polarizing plate, a phase difference plate, and a prism sheet between two board | substrates, respectively. Alternatively, it can be integrated with either of the two substrates.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (may be a part) described in each drawing of this embodiment are applied to and combined with the contents (may be a part) described in the drawings of another embodiment and examples. Or can be freely replaced. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each embodiment with a portion of another embodiment and an example.

Note that in this embodiment, the contents described in other embodiments and examples (may be a part)
Example when embodied, example when slightly modified, example when partially changed, example when improved, example when described in detail, example when applied, example with 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 for driving a display device will be described. In particular, a method for driving a 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 includes an electrode for controlling an electric field applied to the liquid crystal material. A 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 that can obtain desired optical and electrical properties by controlling a voltage applied to a liquid crystal material using an electrode of a substrate. A liquid crystal panel capable of displaying a fine image can be obtained by arranging a large number of electrodes side by side to form a pixel and individually controlling the voltage applied to the pixel.

Here, the response time of the liquid crystal material to the change in electric field is the distance between two substrates (cell gap).
Although it depends on the type of liquid crystal material, it is generally several milliseconds to several tens of milliseconds. Furthermore, when the change amount of the electric field is small, the response time of the liquid crystal material is further increased. This property causes obstacles in image display such as afterimages, tailing, and contrast reduction when displaying moving images on a liquid crystal panel, especially when changing from halftone to another halftone (change in electric field). Is small), the above-mentioned degree of failure becomes significant.

On the other hand, a problem peculiar to a liquid crystal panel using an active matrix is a change in write voltage due to constant charge driving. Hereinafter, constant charge driving in the present embodiment will be described.

A pixel circuit in the active matrix includes a switch for controlling writing and a capacitor for holding charge. The driving method of the pixel circuit in the active matrix is that the switch is turned on and a predetermined voltage is written in the pixel circuit, and then the switch is turned off and the charge in the pixel circuit is held (hold state). In the hold state, no charge is exchanged between the inside and outside of the pixel circuit (constant charge). Usually, the period in which the switch is off is several hundred times (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 a hold state in most periods when the liquid crystal panel is driven.

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

As described above, when the capacitive element whose capacitance is changed by the applied voltage is driven by the above-described constant charge driving, the following problem occurs. That is, there is a problem that when the capacitance of the liquid crystal element changes in the hold state where no charge is transferred, the applied voltage also changes. This can be understood from the fact that the charge amount is constant in the relational expression (charge amount) = (capacitance) × (applied voltage).

For the above reasons, in the liquid crystal panel using the active matrix, the voltage in the hold state changes from the voltage in the writing state 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. This is shown in FIG. FIG. 44A shows a control example of the voltage written in the pixel circuit, with time on the horizontal axis and absolute value of voltage on the vertical axis. FIG. 44B shows a control example of the voltage written to the pixel circuit when the horizontal axis represents time and the vertical axis represents voltage. In FIG. 44C, the horizontal axis represents time, the vertical axis represents the transmittance of the liquid crystal element,
44 shows a 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. 44A to 44C, a period F represents a voltage rewriting cycle, and the time for voltage rewriting is t ₁ , t ₂ , t ₃ , t ₄ ,.
・ I will explain as.

Here, the write 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 ,.
Assume that V ₂ |. (Refer to FIG. 44 (A))

Note that the polarity of the writing voltage corresponding to the image data input to the liquid crystal display device may be periodically switched. (Inversion driving: see FIG. 44B) By this method, it is possible to prevent a direct current voltage from being applied 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. Note that the polarity switching period (inversion period) may be the same as the voltage rewriting period. In this case, since the inversion cycle is short, occurrence of flicker due to inversion driving can be reduced. Further, the inversion cycle may be a cycle that is an integral multiple of the voltage rewrite cycle. In this case, since the inversion period is long and the frequency of writing the voltage by changing the polarity can be reduced, the power consumption can be reduced.

FIG. 44C shows a change over time in the transmittance of the liquid crystal element when a voltage as shown in FIG. 44A or 44B is applied to the liquid crystal element. Here, the voltage | V ₁ is applied to the liquid crystal element.
| Is applied, the transmittance of the liquid crystal element after enough time passes corresponds to TR _1. Similarly, the transmissivity of the liquid crystal element after the voltage | V ₂ | is applied to the liquid crystal element and a sufficient time has elapsed is defined as TR ₂ . When the voltage applied to the liquid crystal element changes from | V ₁ | to | V ₂ | at time t ₁ , the transmittance of the liquid crystal element does not immediately become TR ₂ as indicated by a broken line 30401, It changes slowly. For example, the rewriting period of the voltage, when the same as the frame period of the image signal of 60 Hz (16.7 msec), until the transmittance is changed to TR _2, it is necessary to time of several frames.

However, the smooth transmittance change with time as indicated by a broken line 30401 is obtained 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 the writing state due to constant charge driving. Instead of the time change as shown in FIG. 2, instead of the time change as shown by the solid line 30402. This is because the voltage changes due to the constant charge driving, and the target voltage cannot be reached by one writing. As a result, the response time of the transmissivity of the liquid crystal element is apparently longer than the original response time (broken line 30401), and there are noticeable obstacles in image display such as afterimage, tailing, and contrast reduction. It will cause.

By using the overdrive drive, it is possible to simultaneously solve the phenomenon that the original response time of the liquid crystal element and the apparent response time due to insufficient writing due to dynamic capacitance and constant charge drive become even longer. This state is shown in FIG. FIG. 45A shows a control example of the voltage written in the pixel circuit, with time on the horizontal axis and absolute value of voltage on the vertical axis. FIG. 45B shows a control example of the voltage written to the pixel circuit when the horizontal axis represents time and the vertical axis represents voltage. FIG. 45C illustrates the time when the horizontal axis represents time, the vertical axis represents the transmittance of the liquid crystal element, and the voltage shown in FIG. 45A or 45B is written in the pixel circuit. It shows the change in transmittance over time. 45A to 45C, a period F represents a voltage rewriting cycle, and the time for voltage rewriting 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.
₄ ,... Are assumed to be | V ₂ |. (Refer to FIG. 45 (A))

Note that the polarity of the writing voltage corresponding to the image data input to the liquid crystal display device may be periodically switched. (Reversal drive: see FIG. 45B) By this method, it is possible to prevent a direct current voltage from being applied 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. Note that the polarity switching period (inversion period) may be the same as the voltage rewriting period. In this case, since the inversion cycle is short, occurrence of flicker due to inversion driving can be reduced. Further, the inversion cycle may be a cycle that is an integral multiple of the voltage rewrite cycle. In this case, since the inversion period is long and the frequency of writing the voltage by changing the polarity can be reduced, the power consumption can be reduced.

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.
| Is applied, the transmittance of the liquid crystal element after enough time passes corresponds to TR _1. Similarly, the transmissivity of the liquid crystal element after the voltage | V ₂ | is applied to the liquid crystal element and a sufficient time has elapsed is defined as 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 elapsed is defined as 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 indicated by the broken line 30501 but as indicated 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 the 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 voltage change, 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 voltage, the optimum response time can always be obtained by changing the overdrive voltage | V ₃ | accordingly. is there.

The overdrive voltage | V ₃ | is preferably changed according to the mode of the liquid crystal such as TN, VA, IPS, and OCB. This is because even if the response speed of the liquid crystal varies depending on the mode of the liquid crystal, an optimal response time can always be obtained by changing the overdrive voltage | V ₃ | accordingly.

Note that the voltage rewrite 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 low manufacturing cost can be obtained.

Note that the voltage rewrite 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 the frame period of the input signal, may be 1/3 times, or may be less than that. This method is effective when used in combination with measures for reducing the quality of moving images caused by hold driving of liquid crystal display devices, such as black insertion driving, backlight blinking, backlight scanning, and intermediate image insertion driving by motion compensation. is there. That is, since the response time of the required liquid crystal element is short because the countermeasure method for the deterioration of the moving image quality caused by the hold driving of the liquid crystal display device is relatively easy by using the overdrive driving method described in this embodiment. In addition, the response time of the liquid crystal element can be shortened. Although the response time of the liquid crystal element can be essentially shortened by the cell gap, the liquid crystal material, the liquid crystal mode, and the like, it is technically difficult. Therefore, it is very important to use a method of shortening the response time of the liquid crystal element from the driving method such as overdrive.

Note that the voltage rewriting period F may be longer than the frame period of the input signal. For example,
The voltage rewrite period F may be twice, three times, or more than the frame period of the input signal. This method is effective when used in combination with means (circuit) for determining whether or not voltage rewriting is not performed for a long period of time. That is, when the voltage is not rewritten for a long time, the operation of the circuit 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 is obtained. Can do.

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 | according to 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
1 | and a signal related to the voltage | V ₂ | giving the transmittance TR ₂ , and a signal output from the overdrive circuit is a signal related to the overdrive voltage | V ₃ |. Here, as these signals, voltages applied to the liquid crystal element (| V ₁ |, | V ₂ |
, | 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, an 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 for giving an overdrive voltage.

Here, voltages | V ₁ | and | V ₂ | that give the desired transmittances TR ₁ and TR ₂ are:
Since the image signals are in frames adjacent to each other, the input image signals 3101a and 3101b are preferably image signals in frames adjacent to each other as well. 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 output signal can be used as the input image signal 3101b. An example of the delay circuit 3102 is a memory. That is,
In order to delay the input image signal 3101a by one frame, the input image signal 3101 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 frames adjacent to each other. Then, by inputting image signals in frames adjacent to each other to the correction circuit 3103, an output image signal 3104 is output.
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 in order to delay by one frame. By doing this, without excessive or insufficient memory capacity,
It can have a function as a delay circuit.

Next, a 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 memory capacity can be reduced, so that the manufacturing cost can be reduced.

As the delay circuit 3102 having such characteristics, specifically, a delay 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. 46B is as follows. First,
Before the input image signal 3101a is stored in the memory 3106, the encoder 3105 performs compression processing. As a result, the size of data to be stored in the memory 3106 can be reduced. As a result, since the memory capacity can be reduced, the manufacturing cost can be reduced. Then, the compressed image signal is decoded by the decoder 3107.
The decompression process is performed here. As a result, the previous signal compressed by the encoder 3105 can be restored. Here, the compression / decompression process performed by the encoder 3105 and the decoder 3107 may be a reversible process. In this way, since the image signal is not deteriorated even after the compression / decompression process, the memory capacity can be reduced without degrading the quality of the image finally displayed on the apparatus. Further, the compression / decompression process performed by the encoder 3105 and the decoder 3107 may be an irreversible process. By doing so, the data size of the image signal after compression can be made very small, so that the memory capacity can be greatly reduced.

As a method for reducing the capacity of the memory, various methods can be used in addition to the methods listed above. Rather than compressing the image with an encoder, the color information of the image signal is reduced (for example, the color is reduced from 260,000 colors to 65,000 colors) or the number of data is reduced (the resolution is reduced). The 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 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 a simple calculation, a lookup table (LUT) may be used as the correction circuit 3103. Since the relationship between the two input image signals and the output image signal is 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 FIG. 46C.) By using the LUT 3108 as the correction circuit 3103, the correction circuit 3103 can be realized without complicated circuit design or the like.

Here, 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, a circuit shown in FIG. 46D can be considered. The correction circuit 3103 shown in FIG.
An LUT 3109 and an adder 3110 are included. The LUT 3109 has an input image signal 310.
Difference data between 1a and the output image signal 3104 to be output is stored. That is, the corresponding difference data is converted into the LUT from the input image signal 3101a and the input image signal 3101b.
3109, and the difference data and the input image signal 3101a extracted are added to the adder 31.
By adding by 10, an 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, so that the memory capacity required for the LUT 3109 can be reduced.

Further, if the output image signal can be 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 subtracter, and a multiplier.
As a result, it is not necessary to use an LUT, and the manufacturing cost can be greatly reduced.
An example of such a circuit is the circuit shown in FIG. In (
E) includes a subtractor 3111, a multiplier 3112, and an adder 3113.
Have. First, a subtractor 3111 obtains a difference between the input image signal 3101a and the input image signal 3101b. Thereafter, the multiplier 3112 multiplies the difference value by an appropriate coefficient. Then, a difference value obtained by multiplying the input image signal 3101a by an appropriate coefficient is added to the adder 311.
The output image signal 3104 can be obtained by adding by 3. By using such a circuit, it is not necessary to use an LUT, and the manufacturing cost can be greatly reduced.

Note that by using a correction circuit 3103 shown in FIG. 46E under certain conditions,
An inappropriate output image signal 3104 can be prevented from being output. The conditions are
The difference between the output image signal 3104 giving the overdrive voltage and the input image signal 3101a and the input image signal 3101b is linear. Then, the linearity gradient is used as a coefficient multiplied by the multiplier 3112. That is, it is preferable to use a correction circuit 3103 shown in FIG. 46E for a liquid crystal element having such properties. As a liquid crystal element having such properties, an IPS mode liquid crystal element in which the response speed is small in gradation dependency can be given. In this manner, for example, by using the correction circuit 3103 shown in FIG. 46E for the IPS mode liquid crystal element, the manufacturing cost can be greatly reduced and an inappropriate output image signal 3104 can be output. An overdrive circuit that can be prevented can be obtained.

Note that the same function as the circuits shown in FIGS. 46A to 46E may be realized by software processing. As for the memory used for the delay circuit, other memory included in the liquid crystal display device, memory included in a device that sends an image to be displayed on the liquid crystal display device (for example, a video card included in a personal computer or a similar device, etc.) Can be diverted. By doing so, not only can the manufacturing cost be reduced, but also the user can select the strength of overdrive, the situation of use, etc. according to his / her preference.

Next, driving for manipulating 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 capacitive display element such as a liquid crystal element. FIG. The pixel circuit shown in FIG. 47A includes a transistor 3201, an auxiliary capacitor 3202, a display element 3203, a video signal line 3204, a scanning line 3205, and a common line 3206.

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

First, since the transistor 3201 is turned on in the pixel selected by the scanning line 3205, a voltage corresponding to the video signal is applied to the display element 3203 and the auxiliary capacitor 3202 through the video signal line 3204. At this time, if the video signal is to display the lowest gradation for all the pixels connected to the common line 3206, or the common line 3
When the highest gradation is displayed for all the pixels connected to 206, it is not necessary to write a 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 through the line 4.

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

The gate electrode of the transistor 3211 is electrically connected to the scan line 3215, one of the source electrode and the drain electrode of the transistor 3211 is electrically connected to the video signal line 3214, and the other of the source electrode and the drain electrode of the transistor 3211 Is the auxiliary capacity 3212
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.
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 the number of pixels electrically connected to one common line is small, instead of writing a video signal through the video signal line 3214, the first common line 3
The frequency at which the voltage applied to the display element 3213 can be changed by moving the potential of 216 or the second common line 3217 is significantly increased. Further, source inversion driving or dot inversion driving is possible. By source inversion driving or dot inversion driving, flicker can be suppressed while improving element reliability.

Next, a scanning backlight will be described with reference to FIG. FIG. 66A shows a scanning backlight in which cold cathode fluorescent lamps are juxtaposed. The scanning backlight shown in FIG. 66A includes a diffusion plate 6601 and N cold cathode fluorescent lamps 6602-1 to 6602 -N. N cold cathode tubes 6602-1 to 6602 -N are juxtaposed behind the diffuser plate 6601, so that the N cold cathode tubes 6602-1 to 6602 -N scan with varying luminance. Can do.

A change in luminance of each cold cathode tube during scanning will be described with reference to FIG. First, the luminance of the cold cathode tube 6602-1 is changed for a certain time. Then, after that, the cold cathode fluorescent lamp 660
The luminance 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 sequentially changed from the cold cathode fluorescent lamps 6602-1 to 6602 -N. In FIG. 66C, the luminance to be changed for a certain time is smaller than the original luminance, but may be larger than the original luminance. Further, although the cold cathode fluorescent lamps 6602-1 to 6602 -N are scanned, the cold cathode fluorescent lamps 6602 -N to 6602-1 may be scanned in the reverse direction.

By driving as shown 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 juxtaposed. When an LED is used as the light source of the scanning backlight, there is an advantage that the backlight can be made thin and light. Further, there is an advantage that the color reproduction range can be expanded. Furthermore, L
Since the LEDs juxtaposed to each of the light sources 6612-1 to 6612 -N in which the EDs are juxtaposed can also be scanned in the same manner, a dot scanning backlight can also be used. If the point scanning type is adopted, the image quality of the moving image can be further improved.

Note that even when an LED is used as the light source of the backlight, it can be driven by changing the luminance as shown in FIG.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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, the operation of the display device will be described.

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

A display device 6700 includes a pixel portion 6701, a signal line driver circuit 6703, and a scan line driver circuit 67.
04. In the pixel portion 6701, a plurality of signal lines S1 to Sm are connected to a signal line driver circuit 670.
3 are arranged extending in the column direction. The pixel portion 6701 includes a plurality of scanning lines G1 to G.
n extends from the scanning line driving circuit 6704 in the row direction. A pixel 670 is formed where the plurality of signal lines S1 to Sm and the plurality of scanning lines G1 to Gn intersect each other.
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 includes at least a switching element connected to the signal line.
This switching element is controlled to be turned on and off by the potential of the scanning line (scanning signal). 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, storage capacitor voltage, and the like) changes according to 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 a potential corresponding to the video signal input at the time of selection, the pixel 6702 maintains a voltage corresponding to the video signal (for example, luminance, transmittance, storage capacitor voltage, and the like).

Note that the structure of the display device is not limited to FIG. For example, a wiring (a scanning line, a signal line, a power supply line, a capacitor line, a common line, or the like) may be newly added depending on the structure of the pixel 6702.
As another example, a circuit 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 of FIG. 68 shows one frame period corresponding to a period for displaying an image for one screen. There is no particular limitation on the period of one frame, but the person who sees the image flickers (flicker)
It is preferable to set it to at least 1/60 second or less so as not to feel the above.

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

Note that at the same time as the scanning line is selected, the pixel 6702 connected to the scanning 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 m-th scanning line Gm (hereinafter also referred to as scanning). For example, during the period when the i-th scanning line Gi is selected, scanning lines other than the i-th scanning line Gi (G1 to Gi-1, Gi + 1 to Gm).
) Is not selected. In the next period, the (i + 1) th scanning line Gi + 1 is selected. Note that a period during which one scanning 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 scanning line.

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

Next, a case where one gate selection period is divided into a plurality of subgate 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 (a first subgate selection period and a second subgate selection period).

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

The timing chart of FIG. 69 shows one frame period corresponding to a period for displaying an image for one screen. There is no particular limitation on the period of one frame, but the person who sees the image flickers (flicker)
It is preferable to set it to at least 1/60 second or less so as not to feel the above.

One frame has two subframes (first subframe and second subframe).
It is divided into

The timing chart of FIG. 69 shows the i-th scanning line Gi, the i + 1-th scanning line Gi + 1, j
This shows the timing at which the scanning line Gj in the row (any one of the scanning lines Gi + 1 to Gm), the scanning line in the j + 1th row, and the scanning line Gj + 1 in the Gj + 1th row are selected.

Note that at the same time as the scanning line is selected, the pixel 6702 connected to the scanning 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.

Note that each of the scanning lines G1 to Gm is sequentially scanned within each sub-gate selection period. For example, in a certain gate selection period, the i-th scanning line Gi is selected in the first sub-gate selection period, and the j-th scanning line Gj is selected in the second sub-gate selection period.
Then, in one gate selection period, it is possible to operate as if scanning signals for two rows were selected at the same time. At this time, different video signals are input to the signal lines S1 to Sn in the first sub-gate selection period and the second sub-gate selection period. Therefore,
A plurality of pixels 6702 connected to the i-th row and a plurality of pixels 670 connected to the j-th row
A separate video signal can be input to 2.

Next, a driving method for converting the frame rate of input image data (also referred to as input frame rate) and the display frame rate (also referred to as 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 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. Thus, even when the input frame rate and the display frame rate are different, display can be performed at various display frame rates.

When the input frame rate is higher than the display frame rate, display can be performed by converting a part of the input image data into various display frame rates by discarding part of the input image data.
In this case, since the display frame rate can be reduced, the operating frequency of the drive circuit for display can be reduced, and power consumption can be reduced. On the other hand, when the input frame rate is smaller than the display frame rate, all or part of the input image data is displayed a plurality of times. Another image is generated from the input image data. What is input image data? By using means such as generating an irrelevant image, it is possible to perform display by converting to various display frame rates. 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. Note that the frame rate conversion method when the input frame rate is larger than the display frame rate can be realized by executing the reverse procedure of the frame rate conversion method when the input frame rate is smaller 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 referred to as a basic image. On the other hand, an image that is displayed at a frame rate different from the basic image and that is displayed in order to match the input frame rate and the display frame rate is referred to as an interpolated image. As the basic image, the same image as the input image data can be used. 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, a method of detecting temporal changes (image motion) of the input image data and using these intermediate images as an interpolated image, an image multiplied by a coefficient in the luminance of the basic image A plurality of different images from the input image data, and presenting the plurality of images sequentially in time (one of the plurality of images as a basic image,
There is a method of causing the observer to perceive that an image corresponding to the input image data is displayed by using the rest as an interpolation image. As a method of creating a plurality of different images from 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 intermediate state image (intermediate image) is an image obtained by detecting temporal changes (image motion) of input image data and interpolating the detected motion. Obtaining an intermediate image by such a method is referred to as motion compensation.

Next, a specific example of the frame rate conversion method will be described. According to this method, an arbitrary rational number (n / m) times frame rate conversion can be realized. Here, n and m are integers of 1 or more. The frame rate conversion method in 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 of the images subjected to frame rate conversion in the first step, and the plurality of sub-images are temporally continuous. It is a step for performing the method of displaying. By using the method according to the second step, even though a plurality of different images are actually displayed, it is possible to make the human eye perceive as if the original image was displayed.

The frame rate conversion method in the present embodiment may use both the first step and the second step, omit the first step, and use only the second step. Step 2 may be omitted and only the first step may be used.

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

The period Tin represents the cycle of the input image data. The period of the input image data corresponds to the input frame rate. For example, when the input frame rate is 60 Hz, the cycle of the input image data is 1/60 seconds. Similarly, if the input frame rate is 50 Hz,
The cycle of the input image data is 1/50 second. Thus, the period 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, 24 Hz, 50 Hz, 60 Hz, 70 Hz,
48 Hz, 100 Hz, 120 Hz, 140 Hz, 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 video signals. 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. Note that the frame rate is not limited to double and may be various multiples. Thus, according to the method shown in this embodiment, frame rate conversion can be realized for input signals of various standards.

The procedure for frame rate conversion of an arbitrary rational number (n / m) times in the first step is as follows.
As procedure 1, the k-th interpolation image for the first basic image (k is an integer equal to or greater than 1; the initial value is 1
) Display timing is determined. The display timing of the k-th interpolation image is assumed to be 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.
As a procedure 2, it is determined whether or not the coefficient k (m / n) used for determining the display timing of the k-th 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 a procedure 3, an image used as the kth interpolation image is determined. Specifically, the coefficient k (m / n) used for determining the display timing of the k-th 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 k-th interpolation image is an intermediate image obtained by motion compensation, the k-th interpolation image is (x + 1).
) To the (x + 2) th basic image, an intermediate image obtained as an image corresponding to a motion obtained by multiplying the movement of the image by (y / n). When the kth interpolation image is the same as the basic image, the (x + 1) th basic image can be used. A method for 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 procedure 1.

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

Note that the mechanism for executing the procedure in the first step may be implemented in the apparatus, or may be determined in advance at the design stage of the apparatus. If the mechanism for executing the procedure in the first step is mounted on the apparatus, the driving method can be switched so that the optimum operation according to the situation is performed. The situation here refers to the contents of the 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 determined in advance at the device design stage, an optimal driving circuit can be used for each driving method, and the mechanism is determined. As a result, a reduction in manufacturing cost due to mass production effects can be expected.

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

Next, in procedure 2, it is determined whether or not the coefficient k (m / n) used for determining the display timing of the first interpolation image is an integer. Here, since the coefficient k (m / n) is 1, it is an integer. Accordingly, at the display timing of the first interpolation image, the (k (m / n) +1), 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 a basic image, the (k + 1) -th image is a basic image, and the image display cycle is one time the cycle of input image data. To do.

As a specific expression, when the conversion ratio is 1 (n / m = 1),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
A display device driving method for sequentially displaying (k + 1) th images at intervals equal to the period of input image data,
The k-th image is displayed according to the i-th image data;
The (k + 1) th image is displayed according to the (i + 1) th image data.

Here, when the conversion ratio is 1, since the frame rate conversion circuit can be omitted, 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 as compared with the case where the conversion ratio is smaller than 1. Furthermore, when the conversion ratio is 1, there is an advantage that power consumption and manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 1.

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

Next, in procedure 2, it is determined whether or not the coefficient k (m / n) used for determining 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, go to step 3.

In procedure 3, an image to be used as the first interpolation image is determined. Therefore, the factor 1/2 is set to x
Convert to + y / n form. In the case of the coefficient 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, an intermediate image obtained as an image corresponding to a motion obtained by multiplying the motion of the image from the first basic image to the (x + 2) or second basic image by y / n times, that is, ½ times. First
When the interpolated image is the same as the basic image, the (x + 1) th, that is, the first basic image can be used.

By the procedure so far, the display timing of the first interpolation image and the image to be displayed as the first interpolation image can 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 step 1, the display timing of the second interpolation image with respect to the first basic image is determined. The display timing of the second interpolated image is a point in time when the period of the input image data is multiplied by k (m / n), that is, 1 time has elapsed since the first basic image was displayed.

Next, in step 2, it is determined whether or not the coefficient k (m / n) used for determining 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), 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 a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is a basic image, and the image display cycle is ½ times the cycle of the input image data.

As a specific expression, when the conversion ratio is 2 (n / m = 2),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
A display device driving method for sequentially displaying k + 2 images at intervals of 1/2 times the cycle of input image data,
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 obtained by halving the movement from the i-th image data to the (i + 1) -th image data,
The k + 2th image is displayed according to the i + 1th image data.

As another specific expression, when the conversion ratio is 2 (n / m = 2),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
A display device driving method for sequentially displaying k + 2 images at intervals of 1/2 times the cycle of input image data,
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 + 2th 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 continuously displayed twice 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, so that the quality of the moving image can be significantly improved. Furthermore, when the display device is an active matrix liquid crystal display device,
It brings about a particularly remarkable image quality improvement effect. This is related to the problem of insufficient writing voltage due to so-called dynamic capacitance, in which the capacitance of the liquid crystal element varies depending on the applied voltage. That is, by making the display frame rate larger than the input frame rate, it is possible to increase the frequency of the image data write operation, thereby reducing obstacles such as moving image tailing and afterimage caused by insufficient write voltage due to dynamic capacitance. be able to. Further, it is effective to combine the AC drive and 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 AC drive frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 240 Hz, etc.), It can be reduced to a level not perceived by human eyes.

When n = 3, m = 1, that is, the conversion ratio (n / m) is 3 (where n = 3 and m = 1 in FIG. 70), the operation in the first step is as follows. First, when k = 1, in step 1, the display timing of the first interpolation image with respect to the first basic image is determined. The display timing of the first interpolated image is the period of the input image data after the first basic image is displayed.
/ N) 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 for determining the display timing of the first interpolation image is an integer. Here, since the coefficient k (m / n) is 1/3, it is not an integer. Therefore, go to step 3.

In procedure 3, an image to be used as the first interpolation image is determined. Therefore, the coefficient 1/3 is set to x
Convert to + y / n form. In the case of the coefficient 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, an intermediate image obtained as an image corresponding to a movement obtained by multiplying the movement of the image from the first basic image to the (x + 2) th or second basic image by y / n times, that is, 1/3 times. First
When the interpolated image is the same as the basic image, the (x + 1) th, that is, the first basic image can be used.

By the procedure so far, the display timing of the first interpolation image and the image to be displayed as the first interpolation image can 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 step 1, the display timing of the second interpolation image with respect to the first basic image is determined. The display timing of the second interpolated image is a point in time when a period in which the cycle of the input image data is k (m / n) times, that is, 2/3 times has elapsed since the first basic image is displayed.

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

In procedure 3, an image to be used as the second interpolation image is determined. Therefore, the coefficient 2/3 is set to 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, an intermediate image obtained as an image corresponding to a motion obtained by multiplying the motion of the image from the first basic image to the (x + 2) or second basic image by y / n times, that is, 2/3 times, is used. Second
When the interpolated image is the same as the basic image, the (x + 1) th, that is, the first basic image can be used.

By the procedure so far, the display timing of the second interpolation image and the image to be displayed as the second interpolation image can 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 step 1, the display timing of the third interpolation image with respect to the first basic image is determined. The display timing of the third interpolated image is the time when the period of the input image data cycle k (m / n) times, that is, 1 time has elapsed since the display of the first basic image.

Next, in step 2, it is determined whether or not the coefficient k (m / n) used for determining 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), 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 a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is an interpolation image,
The k + 3 image is a basic image, and the image display cycle is 1/3 times the cycle of the input image data.

As a specific expression, when the conversion ratio is 3 (n / m = 3),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
A display device driving method for sequentially displaying k + 3 images at intervals of 1/3 times the cycle of input image data,
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 obtained by multiplying the movement from the i-th image data to the i + 1-th image data by 1/3,
The k + 2 image is displayed according to image data corresponding to a movement obtained by multiplying the movement from the i-th image to the i + 1-th image by 2/3,
The k + 3 image is displayed according to the (i + 1) th image data.

As another specific expression, when the conversion ratio is 3 (n / m = 3),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
A display device driving method for sequentially displaying k + 3 images at intervals of 1/3 times the cycle of input image data,
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 + 2 image is displayed according to the i-th image data,
The k + 3 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 as compared with the case where the conversion ratio is smaller than 3. Furthermore, when the conversion ratio is 3, there is an advantage that the power consumption and the manufacturing cost can be reduced as compared with the case where 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, for one input image, the image is continuously displayed three times. At this time, when the interpolated image 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 device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, the AC drive of the liquid crystal display device and 180 Hz
It is also effective to combine driving. That is, the driving frequency of the liquid crystal display device is set to 180H.
z, and the frequency of AC driving is an integral multiple or a fraction thereof (for example, 45 Hz, 9
By setting the frequency to 0 Hz, 180 Hz, 360 Hz, etc., flicker that appears due to AC driving can be reduced to a level that is not perceived by human eyes.

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

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

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

By the procedure so far, the display timing of the first interpolation image and the image to be displayed as the first interpolation image can 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 step 1, the display timing of the second interpolation image with respect to the first basic image is determined. The display timing of the second interpolated image is a point in time when a period in which the period of the input image data is k (m / n) times, that is, 4/3 times has elapsed since the first basic image is displayed.

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

In procedure 3, an image to be used as the second interpolation image is determined. Therefore, the coefficient 4/3 is set to 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) An intermediate image obtained as an image corresponding to a movement obtained by multiplying the movement of an image from the second basic image to the (x + 2) or third basic image by y / n times, that is, 1/3 times. Second
When the interpolated image is the same as the basic image, the (x + 1) th, that is, the second basic image can be used.

By the procedure so far, the display timing of the second interpolation image and the image to be displayed as the second interpolation image can 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 step 1, the display timing of the third interpolation image with respect to the first basic image is determined. The display timing of the third interpolated image is the point in time when the period of the input image data period is multiplied by k (m / n), that is, twice after the first basic image is displayed.

Next, in step 2, it is determined whether or not the coefficient k (m / n) used for determining 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), 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 a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is an interpolation image,
The k + 3 image is a basic image, and the image display cycle is 2/3 times the cycle of the input image data.

As a specific expression, when the conversion ratio is 3/2 (n / m = 3/2),
I-th image data (i is a positive integer);
The (i + 1) th image data;
I + 2th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
A display device driving method for sequentially displaying k + 3 images at intervals of 2/3 times the cycle of input image data,
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 obtained by multiplying the motion from the i-th image data to the i + 1-th image data by 2/3,
The k + 2 image has a movement of 1/3 from the i + 1th image to the i + 2th image by 1/3.
Displayed according to the image data corresponding to the doubled movement,
The k + 3 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),
I-th image data (i is a positive integer);
The (i + 1) th image data;
I + 2th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
A display device driving method for sequentially displaying k + 3 images at intervals of 2/3 times the cycle of input image data,
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 + 2 image is displayed according to the (i + 1) th image data,
The k + 3 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. Further, when the conversion ratio is 3/2, the conversion ratio is 3 /
There is an advantage that power consumption and manufacturing cost can be reduced as compared with the case of larger than 2.

Specifically, when the conversion ratio is 3/2, it is also called 3/2 speed drive or 1.5 times speed drive. For example, if the input frame rate is 60 Hz, the display frame rate is 90
Hz (90 Hz drive). Then, for two input images, the images are continuously displayed three times. At this time, when the interpolated image 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. In particular, compared to driving methods with a large driving frequency such as 120 Hz driving (double speed driving) and 180 Hz driving (triple speed driving), the operation frequency of the circuit for obtaining an intermediate image can be reduced by motion compensation, so that an inexpensive circuit can be used. Manufacturing cost and power consumption can be reduced. Furthermore, if the display device is an active matrix liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so
It brings about a particularly remarkable image quality improvement effect against 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 90 Hz, the frequency of AC drive is an integer multiple or a fraction thereof (for example, 3
By setting the frequency to 0 Hz, 45 Hz, 90 Hz, 180 Hz, etc., flicker that appears due to AC driving can be reduced to a level that is not perceived by human eyes.

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

For example, when n = 4, m = 1, that is, the conversion ratio (n / m) is 4 (location where n = 4, m = 1 in FIG. 70),
The kth image is a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is an interpolation image,
The k + 3 image is an interpolation image,
The k + 4th image is a basic image, and the image display cycle is ¼ times the cycle of the input image data.

More specifically, when the conversion ratio is 4 (n / m = 4),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
A display device driving method for sequentially displaying k + 4 images at intervals of 1/4 times the cycle of input image data,
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 obtained by multiplying a movement from the i-th image data to the i + 1-th image data by ¼,
The k + 2 image is displayed in accordance with image data corresponding to a movement that is ½ times the movement from the i-th image data to the i + 1-th image data,
The k + 3 image is displayed according to image data corresponding to a movement obtained by multiplying the movement from the i-th image data to the i + 1-th image data by 3/4,
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),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
A display device driving method for sequentially displaying k + 4 images at intervals of 1/4 times the cycle of input image data,
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 + 2 image is displayed according to the i-th image data,
The k + 3 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 as compared with the case where the conversion ratio is smaller than 4. Further, when the conversion ratio is 4, there is an advantage that power consumption and manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 4.

Specifically, when the conversion ratio is 4, it is also referred to as quadruple speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 240 Hz (240 Hz drive). Then, four images are continuously displayed 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, so that the quality of the moving image can be significantly improved. In particular, 120
Compared to driving methods with a low driving frequency such as Hz driving (double speed driving) and 180 Hz driving (triple speed driving), an intermediate image obtained by motion compensation with higher accuracy can be used as an interpolation image. The movement can be smoothed, and the quality of the moving image can be remarkably improved. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Further, it is effective to combine the AC drive and 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 AC driving frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 40 Hz, 60 Hz, 120 Hz, etc.), It can be reduced to a level not perceived by human eyes.

Further, 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 a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is an interpolation image,
The k + 3 image is an interpolation 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),
I-th image data (i is a positive integer);
The (i + 1) th image data;
I + 2th image data;
I + 3th image data are sequentially input as input image data at a constant cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
A display device driving method for sequentially displaying k + 4 images at intervals of 3/4 times the cycle of input image data,
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 obtained by multiplying the movement from the i-th image data to the i + 1-th image data by 3/4,
The k + 2 image halves the movement from the i + 1th image to the i + 2 image.
Displayed according to the image data corresponding to the doubled movement,
The k + 3 image is a quarter of the movement from the i + 2 image to the i + 3 image.
Displayed according to the image data corresponding to the doubled movement,
The k + 4 image is displayed according to the i + 3 image data.

As another specific expression, when the conversion ratio is 4/3 (n / m = 4/3),
I-th image data (i is a positive integer);
The (i + 1) th image data;
I + 2th image data;
I + 3th image data are sequentially input as input image data at a constant cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
A display device driving method for sequentially displaying k + 4 images at intervals of 3/4 times the cycle of input image data,
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 + 2 image is displayed according to the (i + 1) th image data,
The k + 3 image is displayed according to the i + 2 image data,
The k + 4 image is displayed according to the i + 3 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. Further, when the conversion ratio is 4/3, the conversion ratio is 4 /
There is an advantage that power consumption and manufacturing cost can be reduced as compared with the case of larger than 3.

Specifically, when the conversion ratio is 4/3, it is also referred to as 4/3 times speed driving or 1.25 times speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 8
0 Hz (80 Hz drive). Then, four images are continuously displayed for 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, so that the quality of the moving image can be significantly improved. In particular, compared to driving methods with a large driving frequency such as 120 Hz driving (double speed driving) and 180 Hz driving (triple speed driving), the operation frequency of the circuit for obtaining an intermediate image can be reduced by motion compensation, so that an inexpensive circuit can be used. 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 writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Further, it is effective to combine the AC drive and 80 Hz drive of the liquid crystal display device. That is, while the driving frequency of the liquid crystal display device is 80 Hz, the frequency of AC driving is an integer multiple or a fraction thereof (for example,
By setting the frequency to 40 Hz, 80 Hz, 160 Hz, 240 Hz, etc., flicker that appears due to AC driving can be reduced to a level that is not perceived by human eyes.

Further, for example, n = 5, m = 1, that is, the conversion ratio (n / m) is 5 (n = 5 in FIG. 70).
in the case of m = 1)
The kth image is a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is an interpolation image,
The k + 3 image is an interpolation image,
The k + 4th image is an interpolation image,
The k + 5th image is a basic image, and the image display cycle is 1/5 times the cycle of the input image data.

More specifically, when the conversion ratio is 5 (n / m = 5),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
K + 4th image;
A display device driving method for sequentially displaying k + 5 images at intervals of 1/5 times the cycle of input image data,
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 1/5 times the motion from the i th image data to the i + 1 th image data,
The k + 2 image is displayed according to image data corresponding to a motion that is 2/5 times the motion from the i-th image data to the i + 1-th image data,
The k + 3 image is displayed according to image data corresponding to a movement obtained by multiplying the movement from the i-th image data to the i + 1-th image data by 3/5,
The k + 4 image is displayed in accordance with image data corresponding to a motion obtained by multiplying the motion from the i-th image data to the i + 1-th image data by 4/5,
The k + 5th image is displayed according to the i + 1th image data.

As another specific expression, when the conversion ratio is 5 (n / m = 5),
I-th image data (i is a positive integer);
I + 1-th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
K + 4th image;
A display device driving method for sequentially displaying k + 5 images at intervals of 1/5 times the cycle of input image data,
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 + 2 image is displayed according to the i-th image data,
The k + 3 image is displayed according to the i th image data,
The k + 4 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 as compared with the case where the conversion ratio is smaller than 5. Furthermore, when the conversion ratio is 5, there is an advantage that the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 5.

Specifically, when the conversion ratio is 5, it is also referred to as 5 × speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 300 Hz (300 Hz drive). Then, the image is continuously displayed five times 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, so that the quality of the moving image can be significantly improved. In particular, 120
Compared to driving methods with a low driving frequency such as Hz driving (double speed driving) and 180 Hz driving (triple speed driving), an intermediate image obtained by motion compensation with higher accuracy can be used as an interpolation image. The movement can be smoothed, and the quality of the moving image can be remarkably improved. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, it is also effective to combine AC driving and 300 Hz driving of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 300 Hz and setting the AC driving frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 50 Hz, 60 Hz, 100 Hz, etc.), It can be reduced to a level not perceived by human eyes.

Further, for example, n = 5, m = 2, that is, the conversion ratio (n / m) is 5/2 (n = n in FIG. 70).
5, where m = 2)
The kth image is a basic image,
The k + 1 th image is an interpolated image,
The k + 2 image is an interpolation image,
The k + 3 image is an interpolation image,
The k + 4th image is an interpolation image,
The k + 5th image is a basic image, and the image display cycle is 1/5 times the cycle of the input image data.

More specifically, when the conversion ratio is 5/2 (n / m = 5/2),
I-th image data (i is a positive integer);
The (i + 1) th image data;
I + 2th image data is sequentially input as input image data in a certain cycle,
A k-th image (k is a positive integer);
The (k + 1) th image,
K + 2 image,
K + 3th image;
K + 4th image;
A display device driving method for sequentially displaying k + 5 images at intervals of 1/5 times the cycle of input image data,
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 2/5 times the motion from the i th image data to the i + 1 th image data,
The k + 2 image is displayed according to image data corresponding to a motion obtained by multiplying the motion from the i-th image data to the i + 1-th image data by 4/5,
The k + 3 image is displayed according to image data corresponding to a movement that is 1/5 times the movement from the i + 1th image data to the i + 2 image data,
The k + 4 image is displayed according to image data corresponding to a movement obtained by multiplying the movement from the i + 1th image data to the i + 2 image data by 3/5,
The k + 5 image is displayed according to the i + 2 image data.

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

Here, when the conversion ratio is 5/2, 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 5/2. Further, when the conversion ratio is 5/2, there is an advantage that power consumption and manufacturing cost can be reduced as compared with the case where 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 times speed driving. For example, if the input frame rate is 60 Hz, the display frame rate is 150H.
z (150 Hz drive). Then, for two input images, the images are continuously displayed five times. At this time, when the interpolated image 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. In particular, compared to a driving method with a low 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 interpolated image. It is possible to significantly improve the quality of moving images. Furthermore, compared with a driving method having a high driving frequency such as 180 Hz driving (three times speed driving), the operation frequency of a circuit for obtaining an intermediate image can be reduced by motion compensation, so that an inexpensive circuit can be used, and manufacturing cost and power consumption can be reduced. Can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. 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 set to 150 Hz.
And the frequency of AC driving is an integral multiple or a fraction thereof (for example, 30 Hz, 50
Hz, 75 Hz, 150 Hz, etc.) can reduce flicker that appears due to AC driving to a level that is not perceived by human eyes.

Thus, the conversion ratio can be set as an arbitrary rational number (n / m) by variously setting the positive integers n and m. Detailed explanation is omitted, but in the range where n is 10 or less,
n = 1, m = 1, that is, conversion ratio (n / m) = 1 (1 × speed driving, 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 (triple speed drive, 180 Hz),
n = 3, m = 2, that is, conversion ratio (n / m) = 3/2 (3/2 double speed drive, 90 Hz),
n = 4, m = 1, that is, conversion ratio (n / m) = 4 (4 × speed driving, 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 driving, 300 Hz),
n = 5, m = 2, that is, conversion ratio (n / m) = 5/2 (5/2 double speed drive, 150 Hz),
n = 5, m = 3, that is, conversion ratio (n / m) = 5/3 (5/3 double speed drive, 100 Hz),
n = 5, m = 4, that is, conversion ratio (n / m) = 5/4 (5/4 double speed drive, 75 Hz),
n = 6, m = 1, that is, conversion ratio (n / m) = 6 (6 × speed driving, 360 Hz),
n = 6, m = 5, that is, conversion ratio (n / m) = 6/5 (6/5 double 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 double 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 double 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 double 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, ie 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 double speed drive, 135 Hz),
n = 9, m = 5, that is, conversion ratio (n / m) = 9/5 (9/5 double speed drive, 108 Hz),
n = 9, m = 7, ie 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 double speed drive, 67.5 Hz)
,
n = 10, m = 1, that is, conversion ratio (n / m) = 10 (10 × speed driving, 600 Hz),
n = 10, m = 3, that is, conversion ratio (n / m) = 10/3 (10/3 double 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 double speed drive, 66.7)
Hz),
The above combinations are possible. The frequency notation is an example when the input frame rate is 60 Hz. For other input frame rates, the value obtained by integrating the respective conversion ratios with the input frame rate is the drive frequency.

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

Note that the conversion ratio can be determined depending on how much of the displayed image includes an image that can be displayed without performing motion compensation in the input image data. Specifically, the smaller m is, the larger the ratio of images that can be displayed without performing motion compensation on the input image data. If the frequency of motion compensation is low, the frequency of operation of the circuit that performs motion compensation can be reduced, so that power consumption can be reduced. Furthermore, motion compensation can accurately reflect images that contain errors (image motion is accurately reflected). The possibility that an intermediate image) is not created can be reduced, and the image quality can be improved. As such a conversion ratio, in the range where 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. When such a conversion ratio is used, particularly when an intermediate image obtained by motion compensation is used as an interpolated image, the image quality can be increased and the power consumption can be reduced. This is because when m is 2, the number of images that can be displayed without performing motion compensation on the input image data is relatively large (there is only ½ of the total number of input image data). ,
This is because the frequency of performing motion compensation decreases. Furthermore, when m is 1, the number of images that can be displayed without performing motion compensation on the input image data 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, so that there is 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. In the case where the response time of the liquid crystal element varies depending on the amount of change in voltage applied to the liquid crystal element, the average value of response times in a plurality of typical voltage changes can be obtained. Alternatively, the response time of the liquid crystal element is MPRT (Movin
g Picture Response Time).
The conversion ratio can be determined by frame rate conversion so that the image display cycle is close to the response time of the liquid crystal element. Specifically, the response time of the liquid crystal element is preferably a time from a value obtained by integrating the period of the input image data and the reciprocal of the conversion ratio to a value about half of this value. By doing so, it is possible to obtain an image display cycle that matches 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, in the case where the response time of the liquid crystal element is 3 milliseconds or more and 6 milliseconds or less, the triple-speed driving (180 Hz driving) can be performed, and the response time of the liquid crystal element is 5
In the case of milliseconds to 11 milliseconds, 1.5 times speed driving (90 Hz driving) can be performed, and in the case where the response time of the liquid crystal element is 2 milliseconds to 4 milliseconds, quadruple speed driving (240 Hz driving) When the response time of the liquid crystal element is 6 milliseconds or more and 12 milliseconds or less, 1
. 25-times speed driving (80 Hz driving) can be performed. The same applies to other drive frequencies.

Note that the conversion ratio can also be determined by the trade-off between the quality of moving images, power consumption, and manufacturing cost. That is, increasing the conversion ratio can improve the quality of the moving image, while reducing the conversion ratio can reduce power consumption and manufacturing cost. 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 as compared with the case where 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. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 one time the cycle of the input image data.

When the conversion ratio is 2, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 2, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 2. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 ½ times the cycle of the input image data.

When the conversion ratio is 3, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 3. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 1/3 times the cycle of the input image data.

When the conversion ratio is 3/2, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 3/2, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 3/2. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 2/3 times the cycle of the input image data.

When the conversion ratio is 4, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 4, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 4. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 1/4 times the cycle of the input image data.

When the conversion ratio is 4/3, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 4/3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 4/3. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 3/4 times the cycle of the input image data.

When the conversion ratio is 5, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 5, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 5. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 1/5 times the cycle of the input image data.

When the conversion ratio is 5/2, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 5/2, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 5/2. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 5/3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 5/3. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 as compared with the case where 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. Furthermore, 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 4/5 times the cycle of the input image data.

When the conversion ratio is 6, the moving image quality can be improved as compared with the case where the conversion ratio is smaller than 6, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 6. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 1/6 times the period of the input image data.

When the conversion ratio is 6/5, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 6/5, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 6/5. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 5/6 times the cycle of the input image data.

When the conversion ratio is 7, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 7, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 7. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 7/2, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 7/2. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 2/7 times the cycle of the input image data.

When the conversion ratio is 7/3, the quality of the moving image can be improved compared to the case where the conversion ratio is smaller than 7/3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 7/3. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 3/7 times the cycle of the input image data.

When the conversion ratio is 7/4, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 7/4, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 7/4. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 7/5, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 7/5. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 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. Furthermore, 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 6/7 times the cycle of the input image data.

When the conversion ratio is 8, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 8, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 8. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 1/8 times the cycle of the input image data.

When the conversion ratio is 8/3, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 8/3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 8/3. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 3/8 times the cycle of the input image data.

When the conversion ratio is 8/5, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 8/5, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 8/5. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 8/7, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 8/7. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 9, and the power consumption and manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 9. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 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 as compared with the case where 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. Further, since m is small, high image quality can be obtained while power consumption can be reduced. Furthermore, 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 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. Furthermore, 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 4/9 times the cycle of the input image data.

When the conversion ratio is 9/5, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 9/5, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 9/5. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 9/7, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 9/7. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 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 as compared with the case where the conversion ratio is smaller than 9/8, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 9/8. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 8/9 times the cycle of the input image data.

A conversion ratio of 10 can improve the quality of the video compared to a conversion ratio of less than 10,
The power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 10. Furthermore, m
Therefore, high image quality can be obtained while power consumption can be reduced. Furthermore, by applying 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,
The image quality can be improved.

When the conversion ratio is 10/3, the quality of the moving image can be improved as compared with the case where the conversion ratio is smaller than 10/3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 10/3. Furthermore, since m is large, the movement of the image can be made smoother. Furthermore, 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 3/10 times the cycle of the input image data.

When the conversion ratio is 10/7, the quality of the moving image can be improved as compared with the case where 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. Furthermore, 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 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 as compared with the case where 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. Furthermore, 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 9/10 times the cycle of the input image data.

It is obvious 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 whose frame rate is converted to an arbitrary rational number (n / m) times in the first step (referred to as an original image). ), A method of creating a plurality of different images (sub-images) and presenting the plurality of sub-images continuously in time will be described. In this way, even though a plurality of images are actually presented, it is possible to make human eyes perceive that one original image is displayed.

Here, among 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 for displaying the first sub-image is the same as the timing for displaying the original image determined in the first step. on the other hand,
The sub image displayed after that will be referred to as a second sub image. The timing for displaying the second sub-image can be arbitrarily determined regardless of the timing for displaying the original image determined in the first step. Note that 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 expressed as J (J is an integer of 2 or more). At this time, the sub-image displayed at the same timing as the original image determined in the first step is called the first sub-image, and the sub-image displayed subsequently is displayed. The second sub-image, the third sub-image, ...
, And called the Jth sub-image.

There are various methods for creating a plurality of sub-images from one original image. The main methods include the following methods. 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 a 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 that uses 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 (referred to as a gamma complement method). ).

Each of the methods listed above 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. When this method is used, a circuit for newly creating a sub-image is not operated or it is not necessary to use the circuit itself, so that power consumption and manufacturing cost can be reduced. Particularly in a liquid crystal display device, the first
In this step, it is preferable to use this method after performing frame rate conversion using an intermediate image obtained by motion compensation as an interpolated image. This is because the intermediate image obtained by motion compensation is used as an interpolated image, and the same image is repeatedly displayed while smoothing the motion of the moving image, resulting in insufficient video voltage due to the dynamic capacitance of the liquid crystal element. This is because obstacles such as tailing and afterimage can be reduced.

Next, in the method for distributing the brightness of the original image to a plurality of sub-images, a method for setting the brightness of the image and the length of the period during which the sub-image is displayed will be described in detail. J represents the number of sub-images and is an integer of 2 or more. Lowercase j is distinct from uppercase J. Let j be an integer from 1 to J.
In normal hold driving, the pixel brightness is L, the period 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 Total up to j = J (L
₁ T ₁ + L ₂ T ₂ +... + L _J T _J ) is preferably equal to the product of L and T (LT) (the brightness is unchanged). Furthermore, the 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 remains unchanged and the display cycle of the original image is maintained is referred to as a sub-image distribution condition.

Of the methods for distributing the brightness of the original image to a plurality of sub-images, the black insertion method is a method in which at least one sub-image is a black image. By doing so, since the display method can be made to be an impulse type in a pseudo manner, it is possible to prevent the quality of the moving image from being deteriorated due to the hold type display method. Here, it is preferable to follow the sub-image distribution condition in order to prevent the brightness of the display image from being reduced due to the insertion of the black image. However, if the brightness of the display image is acceptable (such as dark surroundings), or if the user is set to allow the brightness of the display image to be reduced, the sub image It is not necessary to follow the distribution conditions. For example, one sub image may be the same as the original image, and the other sub image may be a black image. In this case, power consumption can be reduced compared to when the sub image distribution condition is followed. Furthermore, in a liquid crystal display device, when one sub-image is set to increase the overall brightness of the original image without limiting the maximum brightness, the brightness of the backlight is increased. Thus, the sub-image distribution condition may be realized. In this case, since the sub image distribution condition can be satisfied without controlling the voltage value written to the pixel, the operation of the image processing circuit can be omitted and the power consumption can be reduced.

The black insertion method is characterized in that L _{j of} all pixels is set to 0 in any one sub-image. By doing so, since the display method can be made to be an impulse type in a pseudo manner, it is possible to prevent a reduction in the quality of the moving image due to the hold type display method.

Of the methods for distributing the brightness of the original image to a plurality of sub-images, the time-division gradation control method divides the brightness of the original image into a plurality of ranges, and controls the brightness in the range. This is a method that uses only one of the sub-images. By doing so, the display method can be made to be a pseudo impulse type without lowering the brightness, so that the deterioration of the quality of the moving image due to the hold method being the display method can be prevented.

As a method of dividing the brightness of the original image into a plurality of ranges, the maximum brightness value (L _max )
There is a method of dividing by the number of sub-images. 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 Is displayed, 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 128 to 255, the brightness of one sub-image is set to gradation 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 human eyes as if the original image was displayed, and it can be made to be a pseudo impulse type, so that the quality of the moving image is deteriorated due to the hold type. Can be prevented. Note that the number of sub-images may be greater than two. For example, when the number of sub-images is 3, the brightness level of the original image (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 they are included in the respective brightness ranges after division. Even if the number of brightness levels is not exactly the same, they may be appropriately distributed.

Note that the time-division gradation control method is also preferable because when the sub-image distribution condition is satisfied, the brightness is not reduced and the same image as the original image can be displayed.

Of the methods that distribute the brightness of the original image to multiple sub-images, the gamma complement method uses one sub-image as a bright image with the gamma characteristics of the original image changed, and the other sub-image as the gamma of the original image. This is a method of obtaining a dark image with changed characteristics. By doing so, the display method can be made to be a pseudo impulse type without lowering the brightness, so that the deterioration of the quality of the moving image due to the hold method being the display method can be prevented. Here, the gamma characteristic is the degree of brightness with respect to the brightness level (gradation). Usually, the gamma characteristic is adjusted to be close to linear. This is because a smooth gradation can be obtained if the change in brightness is proportional to the gradation that is the stage of brightness. In the gamma interpolation method, the gamma characteristic of one of the sub-images is shifted from the linearity, and is adjusted so that it is brighter than the linearity in the intermediate brightness (halftone) region (the halftone becomes a brighter image than the original). )
. Then, the gamma characteristic of the other sub-image is also shifted from the linearity, and is adjusted so as to be darker than the linear in the same halftone region (the halftone becomes an image darker than the original). Here, the amount by which one sub-image is lighter than linear and the amount by which the other sub-image is darker than linear are
It is preferable to make them approximately equal for all gradations. By doing so, it can be perceived by the human eye as if the original image was displayed, and deterioration in the quality of the moving image due to the hold type can be prevented. Note that the number of sub-images may be greater than two. For example, if the number of sub-images is 3, if the gamma characteristics of each of the three sub-images are adjusted so that the total amount from linear to bright and the total amount from linear to dark are approximately equal Good.

Note that the gamma complementing method is also preferable because it can display the same image as the original image without lowering 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 smoothly by itself,
Finally, it has the advantage of improving the quality of the image perceived by the human eye.

The method of using an intermediate image obtained by motion compensation as a sub image is a method in which one sub image is an intermediate image obtained by motion compensation from the preceding and succeeding images. By doing so, the motion of the image can be smoothed, so that the quality of the moving image can be improved.

Next, the relationship between the timing for displaying the sub image and the method for 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 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. In this way, even when the timing for displaying the second sub-image is changed variously, it can be perceived by the human eye as if the original image was displayed. Specifically, if the timing for displaying the second sub-image is advanced, the first sub-image is brightened and the second
The sub-image can be made darker. Furthermore, when the timing for displaying the second sub-image is delayed, the first sub-image can be made darker and the second sub-image can be made lighter. This is because the brightness perceived by human eyes varies depending on the length of the period during which an image is displayed. More specifically, the brightness perceived by the human eye becomes brighter as the image display period is longer and darker as the image display period is shorter. That is, by increasing the timing for displaying 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 increased. As it is, the first sub-image is dark and the second sub-image is bright and perceived by human eyes. As a result, an image different from the original image is perceived by the human eye.
The sub-image can be brighter and the second sub-image can be darker. Similarly, the second
By delaying the timing for displaying the second sub-image, 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 brighter.

Based on the above description, the processing procedure in the second step is shown below.
As procedure 1, a method for 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 using the original image as it is 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. J is an integer of 2 or more.
As procedure 3, the brightness L _j of the pixel in the j-th sub image and the length T _{j of the} period during which the j-th sub image is displayed are determined according to the method selected in procedure 1. According to the procedure 3, the length of the period during which each sub image is displayed and the brightness of each pixel included in each sub image are specifically determined.
As the procedure 4, the original image is processed according to the items determined in the procedures 1 to 3 and actually displayed.
In step 5, the target original image is moved to the next original image. And it returns to the procedure 1.

Note that the mechanism for executing the procedure in the second step may be implemented in the apparatus, or may be predetermined in the apparatus design stage. If a mechanism for executing the procedure in the second step is mounted on the apparatus, it is possible to switch the driving method so that the optimum operation according to the situation is performed. The situation here refers to the contents of the 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 determined in advance at the device design stage, an 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 mass production effects can be expected.

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.

In the procedure 1 in the second step, when a method using the original image as it is as a sub-image is selected, the driving method is as follows.

I-th image data (i is a positive integer);
I + 1-th image data are sequentially prepared at a constant period T,
The period 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 sub image (j is an integer from 1 to J) is formed by juxtaposing 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
L, T, L _j , T _j , a display device driving method that satisfies a sub-image distribution condition,
In all j, the brightness L _j of each pixel included in the j-th sub-image is characterized in that L _j = L for each pixel.
Here, the original image data created in the first step can be used as the image data sequentially prepared at a fixed period T. That is, all the display patterns mentioned in the description of the first step can be combined with the driving method.

When the number J of sub-images is determined as 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 like that.
In FIG. 71, the horizontal axis represents time, and the vertical axis represents various n and m used in the first step.

For example, in the first step, when n = 1, m = 1, that is, when the conversion ratio (n / m) is 1, the driving method as shown in the location of 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 driving). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 120 Hz (120 Hz driving). Then, an image is continuously displayed twice 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 smaller 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 larger than the double speed. Furthermore, in the procedure 1 of the second step,
By selecting a method that uses the original image as a sub-image as it is, it is possible to stop the operation of a circuit that creates an intermediate image by motion compensation, or to omit the circuit itself from the device. Can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Further, it is effective to combine the AC drive and 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 AC drive frequency is an integer multiple or a fraction thereof (for example, 30 Hz, 60 Hz).
, 120 Hz, 240 Hz, etc.), flicker that appears due to AC driving can be reduced to a level that is not perceived by human eyes. Furthermore, 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 ½ times 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 in FIG. 71 where n = 2 and m = 1. At this time, the display frame rate is four times (four times speed driving) the frame rate of the input image data. Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 240 Hz (240 Hz drive). Then, four images are continuously displayed 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 quadruple speed drive, the quality of the moving image can be improved as compared with the case where the frame rate is smaller than the quadruple speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is larger than the quadruple speed. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Furthermore, when the display device is an active matrix liquid crystal display device,
Since the problem of insufficient writing voltage due to dynamic capacitance can be avoided, it brings about a particularly remarkable image quality improvement effect against obstacles such as trailing of moving images and afterimages. Further, it is effective to combine the AC drive and 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 AC driving frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 240 Hz, etc.), It can be reduced to a level not perceived by human eyes. Furthermore, 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 1/4 times 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
) Is 3, the drive method is as shown in FIG. 71 where n = 3 and m = 1. At this time, the display frame rate is 6 times (6 × speed driving) the frame rate of the input image data. Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 360 Hz (360 Hz drive). Then, six images are continuously displayed 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 6 × speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is lower than 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 6 × speed. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Furthermore, when the display device is an active matrix liquid crystal display device,
Since the problem of insufficient writing voltage due to dynamic capacitance can be avoided, it brings about a particularly remarkable image quality improvement effect against obstacles such as trailing of moving images and afterimages. It is also effective to combine AC driving and 360 Hz driving of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 360 Hz and setting the frequency of AC driving to an integer multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 180 Hz, etc.), flicker that appears due to AC driving is It can be reduced to a level not perceived by human eyes. Furthermore, 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 1/6 times the period 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 (three times speed driving) the frame rate of the input image data. Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 180 Hz (180 Hz drive). An image is displayed three 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. Where 3
In the double speed drive, the quality of the moving image can be improved as compared with the case where the frame rate is smaller 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 larger than the triple speed. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Further, it is effective to combine the AC drive and 180 Hz drive of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 180 Hz and setting the AC driving frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 180 Hz, etc.), It can be reduced to a level not perceived by human eyes. Furthermore, 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 1/3 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 in FIG. 71 where n = 4 and m = 1. At this time, the display frame rate is 8 times (8 times speed driving) the frame rate of the input image data. Specifically, for example, when the input frame rate is 60 Hz, the display frame rate is 480 Hz (480 Hz drive). Then, an image is continuously displayed 8 times 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 8 × speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is lower than 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 8 × speed. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Furthermore, when the display device is an active matrix liquid crystal display device,
Since the problem of insufficient writing voltage due to dynamic capacitance can be avoided, it brings about a particularly remarkable image quality improvement effect against obstacles such as trailing of moving images and afterimages. Further, it is effective to combine the AC drive and 480 Hz drive of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 480 Hz and setting the AC driving frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 120 Hz, 240 Hz, etc.), It can be reduced to a level not perceived by human eyes. Furthermore, 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 1/8 times the cycle of the input image data.

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 in FIG. 71 where n = 4 and m = 3.
At this time, the display frame rate is 8/3 times the frame rate of the input image data (8
/ 3 times speed driving). Specifically, for example, if the input frame rate is 60 Hz, the display frame rate is 160 Hz (160 Hz drive). Then, the image is continuously displayed eight times for the three 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 8/3 times speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is smaller than 8/3 times speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is larger than 8/3 times speed. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage.
Furthermore, it is also effective to combine AC driving and 160 Hz driving of the liquid crystal display device. That is, by setting the driving frequency of the liquid crystal display device to 160 Hz and setting the AC driving frequency to an integral multiple or a fraction thereof (for example, 40 Hz, 80 Hz, 160 Hz, 320 Hz, etc.), It can be reduced to a level not perceived by human eyes. Furthermore, 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 3/8 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 in FIG. 71 where n = 5 and m = 1. At this time, the display frame rate is 10 times (10 times speed driving) the frame rate of the input image data. 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 continuously displayed ten times 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 10 × speed driving, the quality of the moving image can be improved as compared with the case where the frame rate is smaller than 10 × speed, and the power consumption and the manufacturing cost can be reduced as compared with the case where the frame rate is larger than 10 × speed. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. It is also effective to combine the AC drive and 600 Hz drive 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 AC driving frequency to an integral multiple or a fraction thereof (for example, 30 Hz, 60 Hz, 100 Hz, 120 Hz, etc.), It can be reduced to a level not perceived by human eyes. Furthermore, 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 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 in FIG. 71 where n = 5 and m = 2.
At this time, the display frame rate is 5 times (5 times speed driving) the frame rate of the input image data. 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 continuously displayed five times 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 5 × speed driving, the quality of the moving image 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 where the frame rate is higher than 5 × speed. In addition, the second
In step 1 of step 1, the method of using the original image as it is as the sub-image is selected, so that 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 apparatus. Power consumption and device manufacturing costs can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, 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 300 Hz, the AC driving frequency is an integer multiple or a fraction thereof (
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. Furthermore, 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 1/5 times the cycle of the input image data.

As described above, in the procedure 1 in the second step, a method of using the original image as it is as a sub-image is selected.
In the 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,
Since the display frame rate can be further doubled with respect to the frame rate conversion of the conversion ratio determined by the values of n and m in this step, the quality of the moving image can be further improved. Furthermore, the quality of the moving image can be improved as compared with the case where the display frame rate is lower 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 higher than the display frame rate.
Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. further,
By increasing the driving frequency of the liquid crystal display device and setting the AC driving frequency to an integral multiple or a fraction thereof, flicker that appears due to AC driving can be reduced to a level that is not perceived by human eyes. Furthermore, the response time of the liquid crystal element is the period of the input image data (
By applying to a liquid crystal display device that is about 1 / (twice the conversion ratio)), the image quality can be improved.

Although detailed description is omitted, it is clear that the same advantages can be obtained in cases other than the conversion ratio 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 double 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-times speed drive, 420 Hz),
n = 7, m = 3, that is, conversion ratio (n / m) = 7/3 (14/3 double speed drive, 280 Hz)
,
n = 7, m = 4, that is, conversion ratio (n / m) = 7/4 (7/2 double 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 double speed drive, 140 Hz),
n = 8, m = 1, that is, conversion ratio (n / m) = 8 (16 × speed driving, 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, ie 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 driving, 1080 Hz),
n = 9, m = 2, that is, conversion ratio (n / m) = 9/2 (9-times speed driving, 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 double speed drive, 216 Hz)
,
n = 9, m = 7, ie 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 double 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 double 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),
The above combinations are possible. The frequency notation is an example when the input frame rate is 60 Hz. For other input frame rates, a value obtained by integrating twice the respective conversion ratios with the input frame rate is the drive frequency.

In the case where n is an integer greater than 10, specific numbers of n and m are not mentioned, 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 greater than 2. This is because if the number of sub-images is relatively small in the second step, such as J = 2, the conversion ratio in the first step can be increased accordingly. Such a conversion ratio is 3, 4, 5, 5/2, 6, 7 in a range where n is 10 or less.
7/2, 7/3, 8, 8/3, 9, 9/2, 9/4, 10, 10/3.
When the display frame rate after the first step is such a value, an advantage of reducing the number of sub-images in the second step (reducing power consumption and manufacturing cost, etc.) by setting J = 3 or more. In addition, it is possible to achieve both the advantages (high quality of moving images, reduction of flicker, etc.) due to the large final display frame rate.

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 has been described 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, when T ₁ <T ₂ is determined, the first sub-image can be made brighter and the second sub-image can be made darker. In addition, the second
If it is determined that T ₁ > T ₂ in the procedure 3 in step S1, the first sub-image can be made darker and the second sub-image can be made lighter. In this way, the original image can be properly perceived by the human eye, 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 it is as the sub image is selected in the procedure 1 as in the above driving method, it may be displayed as it is without changing the brightness of the sub image. 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 further increased to J times 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 lower 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 higher than the display frame rate. Further, in the procedure 1 of the second step, the method of using the original image as it is as the sub-image is selected, so that the operation of the circuit that creates the intermediate image by motion compensation is stopped or the circuit itself is omitted from the apparatus. Therefore, power consumption and device manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, by increasing the driving frequency of the liquid crystal display device and setting the AC driving frequency to an integral multiple or a fraction thereof, flickers that appear due to AC driving can be reduced to a level that is not perceived by human eyes. it can. Furthermore, 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 (1 / (J times the conversion ratio)) times the cycle of the input image data.

For example, when J = 3, the quality of the moving image can be improved more than when the number of sub-images is smaller than 3, and the power consumption and the manufacturing cost can be reduced as compared with the case where the number of sub-images is larger than 3. Have advantages. Further, the response time of the liquid crystal element is (1 of the cycle of the input image data.
By applying to a liquid crystal display device that is approximately / (3 times the conversion ratio)) times, the image quality can be improved.

Furthermore, for example, when J = 4, the quality of the moving image can be improved particularly when the number of sub-images is smaller than 4, and the power consumption and the manufacturing cost are reduced as compared with the case where the number of sub-images is larger than 4. It has the advantage of being able to. Furthermore, by applying to a liquid crystal display device in which the response time of the liquid crystal element is about 1 / (4 times the conversion ratio) of the cycle of the input image data, the image quality can be improved.

Furthermore, for example, when J = 5, the quality of the moving image can be improved particularly when the number of sub-images is smaller than 5, and the power consumption and the manufacturing cost are reduced as compared with the case where the number of sub-images is larger than 5. It has the advantage of being able to. Furthermore, 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 approximately 1 / (5 times the conversion ratio) times the cycle of the input image data.

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

When J = 3 or more, the conversion ratio in the first step can take various values. In particular, when the conversion ratio in the first step is relatively small (2 or less), J = 3
The above is effective. This is because if the display frame rate after the first step is relatively small, J can be increased by that amount in the second step. Such a conversion ratio is 1, 2, 3/2, 4/3, in the range where 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 ratio is 1, 2, 3/2, 4/3, 5 /
The cases of 3, 5/4 are 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, the advantage of the small display frame rate in the first step (the power consumption and the manufacturing cost can be reduced). Reduction) and the advantages (high quality of moving images, reduction of flicker, etc.) due to a large final display frame rate 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.

I-th image data (i is a positive integer);
I + 1-th image data are sequentially prepared at a constant period T,
The period 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 sub image (j is an integer from 1 to J) is formed by juxtaposing 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
L, T, L _j , T _j , a display device driving method that satisfies a sub-image distribution condition,
In at least one j, the brightness L _{j of} all the pixels included in the j-th sub-image is expressed as L _j
= 0.
Here, the original image data created in the first step can be used as the image data sequentially prepared at a fixed period T. That is, all the display patterns mentioned in the description of the first step can be combined with the driving method.

It should be noted that the above driving method can be implemented in combination with respect to various n and m used in the first step.

When the number J of sub-images is determined as 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 like that.
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 is omitted here, but in procedure 1 in the second step, the brightness of the original image It is clear that the same advantage is obtained when the black insertion method is selected among the methods for distributing the image 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. Furthermore, when the display frame rate is high, the quality of the moving image can be improved, and when the display frame rate is low, power consumption and manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, flicker that appears due to AC drive can be reduced to the extent that it is not perceived by the human eye.

Among the methods for distributing the brightness of the original image to the plurality of sub-images in the procedure 1 of the second step, a characteristic advantage of selecting the black insertion method 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,
The power consumption and the manufacturing cost of the device can be reduced. Furthermore, since the impulse-type display method can be made pseudo 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 has been described 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, when T ₁ <T ₂ is determined, the first sub-image can be made brighter and the second sub-image can be made darker. In addition, the second
If it is determined that T ₁ > T ₂ in the procedure 3 in step S1, the first sub-image can be made darker and the second sub-image can be made lighter. In this way, the original image can be properly perceived by the human eye, 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 black insertion method is selected in the method of distributing the brightness of the original image to the plurality of sub-images in the procedure 1 as in the above driving method, the brightness of the sub-image is not changed. Alternatively, it may be displayed as it is. because,
In this case, if the brightness of the sub-image is not changed, the entire brightness of the original image is only darkened and displayed. In other words, by actively using this method for controlling the brightness of the display device, the brightness can be controlled 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 is omitted here. Of the methods for distributing the brightness of the original image to a plurality of sub-images in the procedure 1 in the second step, the black insertion method is used. Obviously, the selected case has similar advantages. 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 to a liquid crystal display device of about double.

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 for distributing the brightness of the original image to the plurality of sub-images, the driving method is as follows.

I-th image data (i is a positive integer);
I + 1-th image data are sequentially prepared at a constant period T,
The period 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 inherent brightness L has a maximum value L _max ,
The j-th sub image (j is an integer from 1 to J) is formed by juxtaposing 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
L, T, L _j , T _j , a display device driving method that satisfies a sub-image distribution condition,
In displaying the inherent 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 sequentially prepared at a fixed period T. That is, all the display patterns mentioned in the description of the first step can be combined with the driving method.

It should be noted that the above driving method can be implemented in combination with respect to various n and m used in the first step.

When the number J of sub-images is determined as 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 like that.
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 is omitted here, but in procedure 1 in the second step, the brightness of the original image It is clear that the same advantage is obtained when the time-division gradation control method is selected among the methods for distributing the image 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. Furthermore, when the display frame rate is high, the quality of the moving image can be improved, and when the display frame rate is low, power consumption and manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, flicker that appears due to AC drive can be reduced to the extent that it is not perceived by the human eye.

Among the methods of distributing the brightness of the original image to the plurality of sub-images in the procedure 1 of the second step, the characteristic advantage of selecting the time-division gradation control method is that the intermediate image is obtained by motion compensation. Since the operation of the circuit for generating the circuit can be stopped or the circuit itself can be omitted from the apparatus, the power consumption and the manufacturing cost of the apparatus can be reduced. further,
Since a pseudo impulse 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 has been described 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, when T ₁ <T ₂ is determined, the first sub-image can be made brighter and the second sub-image can be made darker. In addition, the second
If it is determined that T ₁ > T ₂ in the procedure 3 in step S1, the first sub-image can be made darker and the second sub-image can be made lighter. In this way, the original image can be properly perceived by the human eye, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. In this way, the original image can be properly perceived by the human eye, 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, detailed description is omitted here, but among the methods of distributing the brightness of the original image to a plurality of sub-images in step 1 in the second step, time-division gradation Obviously, when the control method is selected, it has similar advantages. For example, 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 1 / (J times the conversion ratio) of 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 for distributing the brightness of the original image to the plurality of sub-images, the driving method is as follows.

I-th image data (i is a positive integer);
I + 1-th image data are sequentially prepared at a constant period T,
The period 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 sub image (j is an integer from 1 to J) is formed by juxtaposing 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
L, T, L _j , T _j , a display device driving method that satisfies a sub-image distribution condition,
In each sub-image, the brightness change characteristic with respect to the gradation is shifted from linear, and the total amount of brightness shifted from linear to brighter and the total amount of brightness shifted from linear to darker are , It is characterized by being approximately equal in all gradations.
Here, the original image data created in the first step can be used as the image data sequentially prepared at a fixed period T. That is, all the display patterns mentioned in the description of the first step can be combined with the driving method.

It should be noted that the above driving method can be implemented in combination with respect to various n and m used in the first step.

When the number J of sub-images is determined as 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 like that.
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 is omitted here, but in procedure 1 in the second step, the brightness of the original image It is clear that the same advantage is obtained when the gamma complement method is selected among the methods for distributing the image 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. Furthermore, when the display frame rate is high, the quality of the moving image can be improved, and when the display frame rate is low, power consumption and manufacturing cost can be reduced. Further, when the display device is an active matrix type liquid crystal display device, the problem of insufficient writing voltage due to dynamic capacitance can be avoided, so that a particularly remarkable image quality improvement effect is brought about against a failure such as a trailing image or an afterimage. Furthermore, flicker that appears due to AC drive can be reduced to the extent that it is not perceived by the human eye.

In the procedure 1 of the second step, among the methods for distributing the brightness of the original image to a plurality of sub-images, a characteristic advantage of selecting the gamma complement method 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 apparatus, the power consumption and the manufacturing cost of the apparatus can be reduced. Furthermore, since the impulse-type display method can be made pseudo 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 gamma-converting the image data. In this case, there is an advantage that the gamma value can be controlled variously depending on the magnitude of the motion of the moving image. Further, the image data may not be directly gamma-converted, and the sub-image with the changed gamma value may be obtained by changing the reference voltage of the digital-analog converter circuit (DAC). In this case, since the image data is not directly gamma-converted, a circuit for performing gamma conversion can be stopped or the circuit itself can be omitted from the apparatus, so that power consumption and manufacturing cost of the apparatus can be reduced. . 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 smoothly by itself, and finally the human The image quality perceived by the eyes 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 has been described 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, when T ₁ <T ₂ is determined, the first sub-image can be made brighter and the second sub-image can be made darker. In addition, the second
If it is determined that T ₁ > T ₂ in the procedure 3 in step S1, the first sub-image can be made darker and the second sub-image can be made lighter. In this way, the original image can be properly perceived by the human eye, 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 of distributing the brightness of the original image to the plurality of sub-images, when the gamma method is selected, 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. In this way, a circuit that changes the brightness of the entire image can be stopped or the circuit itself can be omitted from the apparatus, so that power consumption and manufacturing cost of the apparatus 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, detailed description is omitted here, but among the methods of distributing the brightness of the original image to a plurality of sub-images in step 1 in the second step, time-division gradation Obviously, when the control method is selected, it has similar advantages. For example, 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 1 / (J times the conversion ratio) of 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 the procedure 2 in the second step, the number of sub-images is determined to be 2,
If it is determined in the procedure 3 in the second step that T1 = T2 = T / 2, the second
The driving method determined by the procedure in this step is as follows.

I-th image data (i is a positive integer);
I + 1-th image data are sequentially prepared at a constant period T,
A k-th image (k is a positive integer);
The (k + 1) th image,
A display device driving method for sequentially displaying k + 2 images at intervals of 1/2 times the period of original image data,
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 obtained by halving the movement from the i-th image data to the (i + 1) -th image data,
The k + 2th 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 sequentially prepared at a fixed period T. That is, all the display patterns mentioned in the description of the first step can be combined with the driving method.

It should be noted that the above driving method can be implemented in combination with respect to various n and m used in the first step.

In the procedure 1 in the second step, the characteristic advantage of selecting the method using the intermediate image obtained by motion compensation as a sub-image is that the intermediate image obtained by motion compensation in the procedure in the first step is selected. When the interpolated image is used, the method for obtaining the intermediate image used in the first step can be used as it is in the second step. That is, a circuit for obtaining an intermediate image by motion compensation can be used not only in the first step but also in the second step, so that the circuit can be used effectively and the processing efficiency can be improved. In addition, since the movement of the image can be further smoothed, 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 has been described 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, when T ₁ <T ₂ is determined, the first sub-image can be made brighter and the second sub-image can be made darker. In addition, the second
If it is determined that T ₁ > T ₂ in the procedure 3 in step S1, the first sub-image can be made darker and the second sub-image can be made lighter. In this way, the original image can be properly perceived by the human eye, and at the same time, the display can be pseudo-impulse driven, so that the quality of the moving image can be improved. In this way, the original image can be properly perceived by the human eye, 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, in step 2,
When a method using an intermediate image obtained by motion compensation as a 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, so that even if the display timing of the second sub-image changes, the image perceived by human eyes does not change. In this case, a circuit that changes the brightness of the entire image can be stopped or the circuit itself can be omitted from the apparatus, so that power consumption and manufacturing cost of the apparatus 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, detailed description will be omitted here, but the same applies when the method using the intermediate image obtained by motion compensation as the sub image is selected in step 1 in the second step. Obviously, it has many advantages. For example, 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 1 / (J times the conversion ratio) of the cycle of the input image data.

Next, a specific example of the frame rate conversion method when the input frame rate and the display frame rate are different will be described with reference to FIG. In the method shown in FIGS. 73A to 73C, it is assumed that a circular region on the image is a region whose position changes depending on the frame, and a triangular region on the image is a region whose position hardly changes depending on the frame. Yes. 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 (conversion ratio is 2). When the conversion ratio is 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 2. Furthermore, when the conversion ratio is 2, there is an advantage that the power consumption and the manufacturing cost can be reduced as compared with the case where the conversion ratio is larger than 2. FIG.
A) schematically shows the temporal change of the displayed image with the horizontal axis as time. Here, the image of interest is referred to as a p-th image (p is a positive integer). The image displayed next to the image of interest is the (p + 1) th image,
For the sake of convenience, how far away from the image of interest the image displayed in front of the image of interest is displayed, such as the (p-1) -th image. I will do it. 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 +
Assume that the image is 4). The period Tin represents the cycle of the input image data. 73A shows a case where the conversion ratio is 2, the period Tin is twice the period from when the p-th image is displayed until the (p + 1) -th image is displayed. It becomes length.

Here, the (p + 1) -th image 7302 is changed from the p-th image 7301 to the (p + 2) -th image 7302.
An image created so as to be in an intermediate state between the p-th image 7301 and the (p + 2) -th image 7303 by detecting the change amount of the image up to 303 may be used. In FIG. 73A, the state of the image in the intermediate state is represented by a region (a circular region) whose position is changed by the frame and a region (a triangular region) whose position is not substantially changed by the frame. That is, the position of the circular area in the (p + 1) -th image 7302 is the p-th image 7301.
And the position in the middle of 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. Thus, smooth display can be performed by performing motion compensation on an object having motion on the image and interpolating the image data.

Further, the (p + 1) -th image 7302 is an image in which the brightness of the image is controlled with a certain rule after being created to be in an intermediate state between the p-th image 7301 and the (p + 2) -th image 7303. May be. The certain rule is, for example, the p-th image 73 as shown in FIG.
When the typical luminance of 01 is L and the typical luminance of the (p + 1) -th image 7302 is Lc, there may be a relationship of L> Lc and L> Lc. Desirably, 0.1L <Lc <0.
There may be a relationship of 8L. More desirably, there may be a relationship of 0.2L <Lc <0.5L. Or conversely, 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 pseudo-impulse type, so that an afterimage of the eye can be suppressed.

Note that typical luminance of an image will be described in detail later with reference to FIG.

In this way, there are two different causes for moving image blur (that is, the movement of the image is not smooth,
And the afterimage of the eye) can be solved at the same time to greatly reduce motion blur.

Further, the (p + 3) -th image 7304 may be created from the (p + 2) -th image 7303 and the (p + 4) -th image 7305 using the same method. That is, the (p
+3) image 7304 is from (p + 2) th image 7303 to (p + 4) th image 7305.
(P + 2) image 7303 and (p + 4)
The image may be an image created so as to be in an intermediate state between the image 7305 and the image brightness controlled according to a certain rule.

FIG. 73B shows a case where the display frame rate is three times the input frame rate (conversion ratio is 3). FIG. 73 (B) schematically shows the temporal change of the displayed image with the horizontal axis as time. The image 7311 is the pth 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, the image 7315 is the (p + 4) th image, and the image 7316 Is the (p + 5) th image, image 7
Assume that reference numeral 317 denotes the (p + 6) th image. The period Tin represents the cycle of the input image data. Note that FIG. 73B illustrates the case where the conversion ratio is 3, so the period Tin is
The length is three times the period from when the p-th image is displayed until the (p + 1) -th image is displayed.

Here, the (p + 1) -th image 7312 and the (p + 2) -th image 7313 are detected by detecting the amount of change in the image from the p-th image 7311 to the (p + 3) -th image 7314, whereby the p-th image 7311 is detected. 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 an area (a circular area) whose position is changed by the frame and an area (a triangular area) whose position is not substantially changed by the frame. That is, the (p + 1) -th image 7312 and the (p +)-th image
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 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) image 7314 is X, the position of the circular region in the (p + 1) -th image 7312 is It may be a position displaced about (1/3) X from the position in the p-th image 7311. Further, the position of the circular region in the (p + 2) -th image 7313 may be a position displaced about (2/3) X from the position in the p-th image 7311. That is, the (p + 1) th image 7
312 and the (p + 2) -th image 7313 are obtained by performing motion compensation and interpolating image data. Thus, smooth display can be performed by performing motion compensation on an object having motion on an image and interpolating image data.

Further, 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 p-th image 7311 and the (p + 3) -th image 7314, and the brightness of the image is constant. The image may be controlled according to the rules. The certain rule is, for example, FIG.
As shown in FIG. 3B, the representative luminance of the p-th image 7311 is L, and the (p + 1) -th image 731 is displayed.
Where Lc1 is the representative luminance and Lc2 is the representative luminance of the (p + 2) -th image 7313, 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 pseudo-impulse type, so that an afterimage of the eye can be suppressed. Or you may make it the image which changes a brightness | luminance appear alternately. By doing so, the cycle in which the luminance changes can be shortened, and flicker can be reduced.

In this way, there are two different causes for moving image blur (that is, the movement of the image is not smooth,
And the afterimage of the eye) can be solved at the same time to greatly reduce motion blur.

Furthermore, 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 using the same method. That is, the (p + 4) th image 7315 and the (p + 5) th image 73
16 is an intermediate state between the (p + 3) image 7314 and the (p + 6) image 7317 by detecting the amount of change in the image from the (p + 3) th image 7314 to the (p + 6) th image 7317. In addition, the image may be an image created by controlling the luminance of the image according to a certain rule.

Note that when the method of FIG. 73B is used, since the display frame rate is large, the movement of the image can follow the movement of the eyes well, and the movement of the image can be displayed smoothly. Can be greatly reduced.

In FIG. 73C, the display frame rate is 1.5 times the input frame rate (conversion ratio 1.5).
). FIG. 73C schematically shows the temporal change of the displayed image with the horizontal axis as time. Image 7321 is the pth 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.
Assume that the image is 3). Although not actually displayed, the image 7325 is input image data and may be used to create the (p + 1) th image 7322 and the (p + 2) image 7323. The period Tin represents the cycle of the input image data. Note that FIG. 73C illustrates the case where the conversion ratio is 1.5;
The length is 1.5 times the period from when the p-th image is displayed until the (p + 1) -th image is displayed.

Here, the (p + 1) -th image 7322 and the (p + 2) -th image 7323 are detected by detecting an image change amount from the p-th image 7321 to the (p + 3) -th image 7324 via the image 7325. Alternatively, an image created so as to be in an intermediate state between the p-th image 7321 and the (p + 3) -th image 7324 may be used. In FIG. 73C, the state of the image in the intermediate state is represented by an area (a circular area) whose position is changed by the frame and an area (a triangular area) whose position is not substantially changed by the frame. That is, the position of the circular area in the (p + 1) th image 7322 and the (p + 2) th image 7323 is the pth image 7.
The position in the middle of the position in 321 and the position in the (p + 3) -th image 7324 is set. 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. Thus, smooth display can be performed by performing motion compensation on an object having motion on an image and interpolating image data.

Further, 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 p-th image 7321 and the (p + 3) -th image 7324, and the brightness of the image is constant. The image may be controlled according to the rules. The certain rule is, for example, FIG.
3 (C), the representative luminance of the p-th image 7321 is L, and the (p + 1) -th image 732 is displayed.
Where Lc1 is the representative brightness and Lc2 is the representative brightness of the (p + 2) -th image 7323, 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 pseudo-impulse type, so that an afterimage of the eye can be suppressed. Or you may make it the image which changes a brightness | luminance appear alternately. By doing so, the cycle in which the luminance changes can be shortened, and flicker can be reduced.

In this way, there are two different causes for moving image blur (that is, the movement of the image is not smooth,
And the afterimage of the eye) can be solved at the same time to greatly reduce motion blur.

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

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

As a method of measuring the luminance of an image, there is a method of measuring the luminance individually for each pixel constituting the image. When this method is used, it is possible to measure the brightness strictly to the details of the image.

However, since the method of measuring the luminance individually for each pixel constituting the image is very labor intensive, another method may be used. As another method for measuring the luminance of the image, there is a method of paying attention to a certain area in the image and measuring the average luminance of the area. By this method, the brightness of the image can be easily measured. In the present embodiment, the luminance obtained by the method of measuring the average luminance of a certain area in the image is referred to as the representative luminance of the image for convenience.

Then, in order to obtain the representative luminance of the image, a description will be given below of which region in the image is focused.

FIG. 74A shows an example of a method in which the luminance of a region (a triangular region) where the position does not substantially change with respect to the change of the image is set as the representative luminance of the image. The period Tin is the period of the input image data, the image 7401 is the pth image, the image 7402 is the (p + 1) th image, the image 7403 is the (p + 2) image, and the first region 7404 is the luminance in the pth image 7401. The measurement region and the second region 7405 are the luminance measurement region and the third region 74 in the (p + 1) -th image 7402.
Reference numeral 06 denotes a luminance measurement region in the (p + 2) -th image 7403, respectively. Here, the first to third regions may be substantially the same as the spatial position in the apparatus.
That is, by measuring the representative luminance of the image in the first to third regions, it is possible to obtain the temporal change in the representative luminance of the image.

By measuring the representative luminance of the image, it can be determined whether or not the display is pseudo-impulse type. For example, the luminance measured in the first region 7404 is L, the second
When the luminance measured in the region 7405 is Lc, if Lc <L, the display can be said to be a pseudo impulse type. In such a case, it can be said that the quality of the moving image is improved.

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

FIG. 74B shows an example of a method of measuring the luminance of the tile-divided region and setting the average value as the representative luminance of the image. A period Tin is a cycle of input image data, and an image 7411.
Is the pth 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 pth 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)
) In the image 7413 in FIG. Here, the first to third
These regions may be substantially the same as the spatial position in the apparatus. That is, by measuring the representative luminance of the image in the first to third regions, it is possible to obtain the temporal change in the representative luminance of the image.

By measuring the representative luminance of the image, it can be determined whether or not the display is pseudo-impulse type. For example, when the average value of all the luminance values measured in the first region 7414 is L and the average value of the luminance values measured in the second region 7415 is Lc, Lc <L. In other words, it can be said that the display is a pseudo impulse type.
In such a case, it can be said that the quality of the moving image is improved.

In the luminance measurement region, the image quality can be improved when the typical amount of change in luminance (relative luminance) of the image with respect to time changes is in the following range. As the relative luminance, for example, the first region 7414 and the second region 7415, the second region 7415 and the third region 7 are used.
416, the ratio of the smaller luminance to the larger luminance for each of the first region 7414 and the third region 7416. That is, when the change amount of the typical luminance of the image with respect to the change of time is 0, the relative luminance is 100%. And the relative luminance is 8
If it is 0% or less, the quality of the moving image can be improved. In particular, if the relative luminance is 50% or less, the quality of the moving image can be significantly improved. Furthermore, if the relative luminance is 10% or more, power consumption can be reduced and flicker can be suppressed. In particular, when the relative luminance is 20% or more, power consumption and flicker can be significantly reduced. That is, the relative luminance is 10% or more and 80
If it is less than or equal to%, the quality of moving images 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 the moving image can be remarkably improved, and the 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 as the representative luminance of the image. The period Tin is the cycle of the input image data, the image 7421 is the pth image, the image 7422 is the (p + 1) th image, the image 7423 is the (p + 2) image, and the first region 7424 is the luminance in the pth image 7421. The measurement region, the second region 7425 is the (p
The brightness measurement region in the (+1) image 7422 and the third region 7426 represent the brightness measurement region in the (p + 2) image 7423, respectively.

By measuring the representative luminance of the image, it can be determined whether or not the display is pseudo-impulse type. For example, the luminance measured in the first region 7424 is L, the second
When the luminance measured in the region 7425 is Lc, if Lc <L, the display can be said to be a pseudo impulse type. In such a case, it can be said that the quality of the moving image is improved.

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

FIG. 74D shows 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 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 regions in the (p + 2) -th image 7433, respectively.

By measuring the representative luminance of the image, it can be determined whether or not the display is pseudo-impulse type. For example, assuming that the average value of all the luminance values measured in the first region 7434 is L and the average value of all the luminance values measured in the second region 7435 is Lc, Lc <L. In other words, it can be said that the display is a pseudo impulse type.
In such a case, it can be said that the quality of the moving image is improved.

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

74E is a diagram showing a measurement method in the luminance measurement region in the diagrams shown in FIGS. 74A to 74D. 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. Since the measurement target range of a luminance measuring device with high time resolution may be small, if the region 7441 is large, the entire region 7441 is not measured, but the region 7441 is pointed as shown in FIG. The brightness of the region 7441 may be obtained by measuring at a plurality of points without unevenness in the shape and calculating the average value.

When the image has a combination of the three primary colors R, G, and B, the measured luminance is R, G
, B may be combined, R and G combined, G and B combined, B and R combined, or each of R, G, B 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 for controlling the driving method according to the movement of the image included in the input image data will be described.

With reference to FIG. 75, an example of a method of detecting an image motion included in input image data and creating an intermediate image will be described. FIG. 75A illustrates a case where the display frame rate is twice the input frame rate (conversion ratio is 2). FIG. 75A schematically shows a method of detecting the motion of an image using the horizontal axis as time. The period Tin is the cycle of the input image data, the image 7501 is the pth image, the image 7502 is the (p + 1) th image,
An image 7503 represents the (p + 2) th image. In addition, the first region 7504, the second region 7505, and the third region 750 are included in the image as time-independent regions.
6 is provided.

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

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

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

Next, a vector 7509 is derived as an amount representing a difference in position between the derived first region 7504 and the third region 7506. The vector 7509 is referred to as a motion vector.

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

Here, the vector 7510 obtained from the motion vector 7509 is referred to as 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 a displacement vector 7510. Note that the displacement vector 7510 has a coefficient (1/2) to the motion vector 7509.
It may be the amount multiplied.

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

In this way, 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. The above processing is also performed on other regions in the (p + 2) -th image 7503, so that the (
The (p + 1) -th image 7, which is an intermediate state between the (p + 2) image 7503 and the p-th image 7501
502 can be formed.

FIG. 75B illustrates a case where the display frame rate is three times the input frame rate (conversion ratio is 3). FIG. 75B schematically shows a method of detecting the motion of an image with the horizontal axis as time. The period Tin is the period of the input image data, and the image 7511
Represents the (p + 1) th image, image 7512 represents the (p + 1) th image, image 7513 represents the (p + 2) th image, and image 7514 represents the (p + 3) th image. In addition, the first region 7515, the second region 7516, and the third region 7517 are regions that do not depend on time in the image.
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,
Attention is paid to 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.
Note the range greater than 8. Here, the fourth region 7 centered on the fourth region 7518.
A range larger than 518 is a 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 ranges obtained by enlarging the horizontal range and the vertical range of the fourth region 7518 by about 15 pixels, respectively.

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

Next, a vector 7521 is derived as an amount representing the difference in position between the derived first region 7515 and the fourth region 7518. Note that the vector 7521 is referred to as a motion vector.

In the (p + 1) th image 7512 and the (p + 2) th image 7513,
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 p-th image 7511 A second region 7516 and a third region 7517 are formed.

Here, the vector 7522 obtained from the motion vector 7521 is referred to as a first displacement vector. 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). In addition, 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 region 7516 in the (p + 1) -th image 7512 is the (p + 3) -th image.
) Image data in the fourth region 7518 in the image 7514 and image data in the first region 7515 in the p-th image 7511. For example,
The image data in the second region 7516 in the (p + 1) -th image 7512 is the (p + 3) -th image.
) Image data in the fourth region 7518 in the image 7514 and the average value of the image data in the first region 7515 in the p-th image 7511.

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

In this way, 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. Note that the above processing is
(p + 3) image 751 is also performed on other regions in image 7514 of p + 3).
The (p + 1) th image 7512 and the (p +)
The image 7513 of 2) can be formed.

Next, an example of a circuit that detects the movement of an image included in input image data and creates an intermediate state image will be described with reference to FIG. FIG. 76A illustrates a connection relation 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 for controlling 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 illustrating an example of a detailed circuit configuration of an image processing circuit included in the control circuit. FIG. 76D is a diagram showing another example of a detailed circuit configuration of the image processing circuit included in the control circuit.

As shown 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 over which the display region 7614 is formed.

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

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

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

The gate driver 7613 includes a gate start pulse 7606 and a gate clock 7607.
And a signal for designating timing for writing a signal output from the source driver 7612 in the display area 7614 may be output.

In the case where the frequency of the external image signal 7600 and the frequency of the image signal 7603 are different, a signal for controlling the timing for driving the source driver 7612 and the gate driver 7613 is also the input horizontal synchronization signal 7601 and vertical synchronization signal 7602. Will have different frequencies. Therefore, in addition to the processing of the image signal 7603, it is 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 for that purpose. For example, when the frequency of the image signal 7603 is double the frequency of the external image signal 7600, the control circuit 7611 generates an image signal 7603 having a double frequency by interpolating the image signal included in the external image signal 7600. In addition, the signal for controlling the timing is also controlled to be double the 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 configuration in which the external image signal 7600 and the frequency control signal 7608 are input and the image signal 7603 is output.

The timing generation circuit 7616 receives a horizontal synchronization signal 7601 and a vertical synchronization signal 7602, a source start pulse 7604, a source clock 7605, a gate start pulse 7606, a gate clock 7607, a frequency control signal 7608, May be output. Note that the timing generation circuit 7616 generates a frequency control signal 760.
A memory or a register for holding data for designating the eight states may be included. Further, the timing generation circuit 7616 may be configured to receive a signal that specifies the state of the frequency control signal 7608 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 a high-speed processing circuit 7625 may be included.

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

The first memory 7621 receives an external video signal 7600 and the external video signal 7600.
May be configured to output the external video signal 7600 to the motion detection circuit 7620 and the second memory 7622 while holding for a predetermined period.

The second memory 7622 receives the image data output from the first memory 7621,
The image data may be output to the motion detection circuit 7620 and the high-speed processing circuit 7625 while holding the image data for a certain period.

The third memory 7623 receives the image data output from the motion detection circuit 7620, and
The image data may be output to the luminance control circuit 7624 while holding the image data for a certain period.

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 the image data is converted into an image signal 7603. The structure which outputs may be sufficient.

When the frequency of the external image signal 7600 is different from the frequency of the image signal 7603, 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. At that time, the second memory 7622 holds image data input in the previous frame. The motion detection circuit 7620 reads the image data held in the first memory 7621 and the second memory 7622 as appropriate, detects a motion vector from the difference between the two image data, and further generates intermediate state image data. May be. The generated intermediate state image data is held in 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. Thereafter, the image data held in the third memory 7623 is converted into the luminance control circuit 7624.
And output as an image signal 7603. At this time, the second memory 7622 and the third memory
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 present invention is not limited to this, and various frequencies can be used. Note that the frequency of the image signal 7603 may be specified by the frequency control signal 7608.

The configuration of the image processing circuit 7615 illustrated in FIG. 76D is obtained by adding a fourth memory 7626 to the configuration 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 is also the motion detection circuit 7620.
It is possible to accurately detect the motion of the image.

If the input image data already contains a motion vector for data compression or the like, for example, MPEG (Moving Picture Expert Gr
In the case of image data based on the (up) standard, an intermediate state image may be generated as an interpolated image using the image data. At this time, a portion for generating a motion vector included in the motion detection circuit 7620 is not necessary. In addition, since the encoding and decoding processing related to the image signal 7623 is simplified, power consumption can be reduced.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

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

Note that the present embodiment is an example in which the contents (may be part) described in other embodiments are embodied, an example in which the content is slightly modified, an example in which a part is changed, and an improvement. An example of the case,
An example in the case of detailed description, an example in the case 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, a structure and a manufacturing method of a transistor will be described.

FIG. 48 is a diagram illustrating an example of a structure of a transistor included in a display device according to the present invention and a manufacturing method thereof. FIG. 48A illustrates an example of a structure of a transistor included in a display device according to the present invention. 48B to 48G illustrate 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 illustrated in FIGS. 48A to 48C, 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 will be described with reference to FIG. FIG. 48A is a cross-sectional view of a plurality of transistors having different structures. Here, in FIG. 48A, a plurality of transistors having different structures are shown side by side, but this is for explaining the structure of the transistors included in the display device of the present invention. As shown in FIG. 48 (A), they need not be juxtaposed, and can be created 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 such as barium borosilicate glass or alumino borosilicate glass, a quartz substrate, a ceramic substrate, a metal substrate including stainless steel, or the like can be used.
In addition, polyethylene terephthalate (PET), polyethylene naphthalate (PEN)
It is also possible to use a substrate made of a synthetic resin having flexibility such as plastic or acrylic represented by polyethylene-tersulfone (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 alkali metal such as Na or alkaline earth metal from the substrate 4011 from adversely affecting the characteristics of the semiconductor element. As the insulating film 4012, 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) It is possible to provide a single layer structure or a laminated structure thereof.
For example, in the case where the insulating film 4012 is provided with a two-layer structure, a silicon nitride oxide film may be provided as a first insulating film and a silicon oxynitride film may be provided as a second insulating film. In the case where the insulating film 4012 is provided with a three-layer structure, a silicon oxynitride film is provided as a first insulating film, a silicon nitride oxide film is provided as a second insulating film, and an oxynitriding film is used as a third insulating film. A silicon film may be provided.

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 structure (including single crystal and polycrystal),
A semiconductor having a third state which is stable in terms of free energy, and includes a crystalline region having short-range order and lattice distortion. In at least a part of the region of the film, 0.5 to 20
A crystal region of nm can be observed, and when silicon is the main component, the Raman spectrum is shifted to a lower wave number side than 520 cm ⁻¹ . In X-ray diffraction, diffraction peaks of (111) and (220) that are derived from the silicon crystal lattice are observed. As a compensation for dangling bonds (dangling bonds), hydrogen or halogen is contained at least 1 atomic% or more. The SAS is formed by glow discharge decomposition (plasma CVD) of a material gas. As the material gas, SiH ₄ , Si ₂ H ₆ , SiH ₂ Cl ₂ , SiHCl ₃ , SiC, etc.
l ₄ , SiF ₄ or the like can be used. 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.
The range of 1 Pa to 133 Pa, the power supply frequency is 1 MHz to 120 MHz, preferably 13 MH
z-60 MHz. The substrate heating temperature may be 300 ° C. or less. As an impurity element in the film, oxygen,
Impurities of atmospheric components such as nitrogen and carbon are desirably 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 known material (a sputtering method, an LPCVD method, a plasma CVD method, or the like) with a material (eg, SixGe1-x) containing silicon (Si) as a main component. 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 furnace annealing furnace, or a thermal crystallization method using a metal element that promotes crystallization.

The insulating film 4016 includes silicon oxide (SiOx), silicon nitride (SiNx), and silicon oxynitride (Si
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 can be used.

The gate electrode 4017 can have a single-layer conductive film or a stacked structure of two-layer or three-layer conductive films. As a material of the gate electrode 4017, a known conductive film can be used. For example, tantalum (Ta), titanium (Ti), molybdenum (Mo), tungsten (
W), chromium (Cr), silicon (Si), etc., elemental films, nitride films of these elements (typically tantalum nitride films, tungsten nitride films, titanium nitride films), or combinations of these elements Alloy film (typically Mo-W alloy, Mo-Ta alloy), or
Silicide film of the element (typically tungsten silicide film, titanium silicide film)
Etc. can be used. Note that the single film, nitride film, alloy film, silicide film, and the like described above may be used as a single layer or may be stacked.

The insulating film 4018 is formed by known means (such as sputtering or plasma CVD) by using silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x> y), silicon nitride oxide (SiNxOy) ( It can be provided by a single layer structure of an insulating film containing oxygen or nitrogen such as x> y) or a film containing carbon such as DLC (diamond like carbon), or a laminated structure thereof.

The insulating film 4019 is made of siloxane resin, silicon oxide (SiOx), silicon nitride (Si
Nx), silicon oxynitride (SiOxNy) (x> y), silicon nitride oxide (SiNxOy) (x
> Y) such as an 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, polyvinyl phenol, benzocyclobutene, and acrylic Can be provided in a single layer structure or a stacked structure. Note that a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of 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. 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 a substituent. Note that in the display device applicable to the present invention, the insulating film 4019 can be provided directly 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, or Mn, a nitride film of the element, or an alloy film that combines the elements, or A silicide film of the above element can be used. For example, as an alloy containing a plurality of the above 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 stacked structure, a structure in which Al is sandwiched between Mo, Ti, or the like can be used.
By carrying out like this, the tolerance with respect to the heat | fever and chemical reaction of Al can be improved.

Next, characteristics of each structure will be described with reference to cross-sectional views of a plurality of transistors having different structures shown in FIG.

The transistor 4001 is a single drain transistor and can be manufactured by a simple method, and thus has an advantage of low manufacturing cost and high yield. Here, the semiconductor layer 4
013 and 4015 have different impurity concentrations, the semiconductor layer 4013 functions as a channel region, and the semiconductor layer 4015 functions as a source region and a drain region. Thus, the resistivity of the semiconductor layer can be controlled by controlling the amount of impurities. Further, the electrical connection state between the semiconductor layer and the conductive film 4023 can be made 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 using the gate electrode 4017 as a mask can be used.

The transistor 4002 has a taper angle greater than or equal to a certain value in the gate electrode 4017 and can be manufactured by a simple method, and thus has an advantage of low manufacturing cost and high yield. 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 (Lighttl).
The y Doped Drain (LDD) region and the semiconductor layer 4015 are used as a source region and a drain region. Thus, the resistivity of the semiconductor layer can be controlled by controlling the amount of impurities. Further, the electrical connection state between the semiconductor layer and the conductive film 4023 can be made close to ohmic connection. In addition, since the LDD region is included, a high electric field is hardly applied inside the transistor, and deterioration of the element due to hot carriers can be suppressed. Note that as a method of separately forming semiconductor layers having different amounts of impurities, a method of doping impurities into the semiconductor layers using the gate electrode 4017 as a mask can be used. Since the gate electrode 4017 has a taper angle, the transistor 4002 can have a gradient in the concentration of impurities that pass through the gate electrode 4017 and is doped into the semiconductor layer, so that an LDD region can be easily formed. can do.

The transistor 4003 includes at least two gate electrodes, and the lower gate electrode 4
017a is a transistor having a shape longer than that of the upper gate electrode 4017b. In this specification, the shape of the upper gate electrode and the lower gate electrode is referred to as a hat shape.
LDD without the addition of a photomask due to the shape of the gate electrode is a hat type
Regions can be formed. Note that a structure in which the LDD region overlaps with the gate electrode as in the transistor 4003 is particularly a GOLD structure (Gate Overlapped L).
DD). Note that the following method may be used as a method of making the shape of the gate electrode a hat shape.

First, when patterning the gate electrode, the lower gate electrode and the upper gate electrode are etched by dry etching so that the side surfaces are inclined (tapered). Subsequently, the upper-layer gate electrode is processed to be nearly vertical by anisotropic etching.
Thereby, a gate electrode having a hat-shaped cross section is formed. After that, by doping the impurity element twice, the semiconductor layer 4013 used as a channel region, the semiconductor layer 4014 used as an LDD region, and the semiconductor layer 40 used as a source electrode and a drain electrode
15 is formed.

Note that an LDD region overlapping with the gate electrode is referred to as a Lov region, and an LDD region not overlapping with the gate electrode is 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 in the vicinity of the drain and preventing 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 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 corresponding to a required characteristic for each of various circuits. For example, in the case where a display device that can be applied to the present invention is used as the display device, it is preferable to use a transistor having a Loff region as the pixel transistor in order to suppress an off-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 relax the electric field in the vicinity of the drain and prevent deterioration of the on-current value.

The transistor 4004 is in contact with the side surface of the gate electrode 4017 and is connected to the side wall 4021.
A transistor having By having the side wall 4021, an area overlapping with the side wall 4021 can be an LDD area.

The transistor 4005 is doped with LDD by doping the semiconductor layer with a mask.
This is a transistor in which a (Loff) region is formed. Thus, the LDD region can be formed reliably and the off-state current value of the transistor can be reduced.

The transistor 4006 is doped with LDD by doping a semiconductor layer with a mask.
This is a transistor in which a (Lov) region is formed. Thus, the LDD region can be formed reliably, the electric field in the vicinity of the drain of the transistor can be relaxed, and the deterioration of the on-current value can be reduced.

Next, an example of a method for manufacturing a transistor included in the display device of the present invention will be described with reference to FIGS.

Note that the structure and manufacturing method of the transistor included in the display device of the present invention are not limited to those illustrated in FIGS. 48A to 48C, 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 are used.
4015, the surface of 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. In this manner, the surface of the semiconductor layer or the insulating film is modified by oxidizing or nitriding the semiconductor layer or the insulating film using plasma treatment, and compared with an insulating film formed by a CVD method or a sputtering method. A denser insulating film can be formed. Therefore, defects such as pinholes can be suppressed and the characteristics of the display device can be improved.

First, the surface of the substrate 4011 is cleaned using hydrofluoric acid (HF), alkali, or pure water. The substrate 4011 is a glass substrate such as barium borosilicate glass or alumino borosilicate 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 plastics typified by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polyethersulfone (PES), or a synthetic resin having flexibility such as acrylic is used. It is also possible to use it. Note that here, a case where a glass substrate is used as the substrate 4011 is described.

Here, plasma treatment is performed on the surface of the substrate 4011 to oxidize or nitride the substrate 4011.
An oxide film or a nitride film may be formed on the surface (FIG. 48B). Hereinafter, 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 treatment insulating film. Note that in FIG. 48B, the insulating film 4031 is a plasma-treated insulating film. In general, when a semiconductor element such as a thin film transistor is provided on a glass or plastic substrate, an impurity element such as an alkali metal such as Na or alkaline earth metal contained in the glass or plastic is mixed in the semiconductor element. This may affect the characteristics of the semiconductor element. However, by nitriding the surface of a substrate made of glass or plastic, it is possible to prevent an impurity element such as an alkali metal or an alkaline earth metal such as Na contained in the substrate from entering the semiconductor element.

Note that when the surface is oxidized by plasma treatment, an oxygen atmosphere (eg, oxygen (O ₂
) And a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, oxygen and hydrogen (H ₂ ) and a rare gas atmosphere, or dinitrogen monoxide and a rare gas atmosphere. )
Plasma treatment is performed at On the other hand, when the semiconductor layer is nitrided by plasma treatment, in a nitrogen atmosphere (for example, nitrogen (N ₂ ) and a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, or Plasma treatment is performed in an atmosphere of nitrogen, hydrogen, and a rare gas, or NH ₃ and a rare gas. As the rare gas, for example, Ar or a mixed gas of Ar and Kr can be used. Therefore, the plasma processing insulating film includes a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) used for the plasma processing. For example, when Ar is used, Ar is contained in the plasma processing insulating film.

In the plasma treatment, the electron density is 1 × 10 ¹¹ cm ⁻³ in the gas atmosphere.
1 × 10 ¹³ cm ⁻³ or less and the plasma electron temperature is 0.5 ev or more and 1.5 eV.
It is preferable to process in the following. This is because the electron density of plasma is high and the electron temperature in the vicinity of the object to be processed is low, so that damage to the object to be processed can be prevented. Moreover, 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 object to be irradiated using plasma treatment has excellent uniformity such as a 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, oxidation or nitridation can be performed at a lower temperature than conventional plasma treatment or thermal oxidation. For example, even if the plasma treatment is performed at a temperature that is 100 degrees or more lower than the strain point temperature of the glass substrate, the oxidation or nitriding treatment can be sufficiently performed. Note that a high frequency such as a microwave (2.45 GHz) can be used as a frequency for forming plasma. Note that the plasma treatment is performed using the above conditions unless otherwise specified.

Note that FIG. 48B illustrates the case where a plasma treatment insulating film is formed by performing plasma treatment on the surface of the substrate 4011; however, in this embodiment, a plasma treatment insulating film is formed on the surface of the substrate 4011. This includes cases where it is not formed.

Note that in FIGS. 48C to 48G, a plasma treatment insulating film formed by performing plasma treatment on the surface of an object to be processed is not shown, but in this embodiment mode, a substrate 40 is used.
11 includes a case where a plasma treatment insulating film formed by performing plasma treatment exists on the surface of the insulating film 4012, the semiconductor layers 4013, 4014, and 4015, the insulating film 4016, the insulating film 4018, or the insulating film 4019.

Next, known means (a sputtering method, an LPCVD method, a plasma CVD method, etc.) on the substrate 4011
An insulating film 4012 is formed 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 to obtain a dense film with few defects such as pinholes. Further, by oxidizing the surface of the insulating film 4012, a plasma processing insulating film with a low N atom content can be formed. Therefore, when a semiconductor layer is provided in the plasma processing insulating film, the plasma processing insulating film and the semiconductor are provided. Layer interface characteristics are improved. The plasma treatment insulating film is formed of a rare gas (He, Ne, Ar,
Including at least one of Kr and Xe). Note that the plasma treatment can be similarly performed under the above-described 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 using silicon (Si) as a main component on the insulating film 4012 by a known means (sputtering method, LPCVD method, plasma CVD method, or the like).
For example, an amorphous semiconductor layer can be formed using, for example, SixGe1-x), the amorphous semiconductor layer is crystallized, and the semiconductor layer is selectively etched. In addition,
For crystallization of the amorphous semiconductor layer, a laser crystallization method, a thermal crystallization method using an RTA or furnace annealing furnace, a thermal crystallization method using a metal element that promotes crystallization, or a combination of these methods, etc. It can carry out by the well-known crystallization method. Note that here, the end portion of the island-shaped semiconductor layer is provided in a shape close to a right angle (θ = 85 to 100 °). Alternatively, the semiconductor layer 4014 serving as the low concentration drain region may be formed by doping impurities using a mask.

Here, plasma treatment is performed on the surfaces of the semiconductor layers 4013 and 4014, and the semiconductor layers 4013 and 4013.
A plasma treatment 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
Is used as the plasma processing insulating film, silicon oxide (SiOx) or silicon nitride (SiN)
x) is formed. Alternatively, the semiconductor layers 4013 and 4014 may be oxidized by plasma treatment and then nitrided by performing plasma treatment again. 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 in the case where the semiconductor layer is oxidized by plasma treatment, oxygen (O ₂ ) and rare gas (He, Ne, A, etc.) are used in an oxygen atmosphere.
plasma treatment is performed in an atmosphere (including at least one of r, Kr, and Xe), oxygen, hydrogen (H ₂ ), and a rare gas atmosphere or dinitrogen monoxide and a rare gas atmosphere. On the other hand, when the semiconductor layer is nitrided by plasma treatment, in a nitrogen atmosphere (for example, nitrogen (N ₂ ) and a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, or Plasma treatment is performed in an atmosphere of nitrogen, hydrogen, and a rare gas, or NH 3 and a rare gas. As the rare gas, for example, Ar can be used. A gas in which Ar and Kr are mixed may be used. Therefore, the plasma treatment insulating film is formed of a rare gas (He, Ne, etc.) used for the plasma treatment.
, Ar, Kr, and Xe). For example, when Ar is used, Ar is contained in the plasma processing insulating film.

Next, an insulating film 4016 is formed (FIG. 48E). The insulating film 4016 is formed using known means (sputtering method, LPCVD method, plasma CVD method, or the like) using silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy) (x> y), or oxynitridation. Silicon (SiNx
A single layer structure of an insulating film containing oxygen or nitrogen, such as Oy) (x> y), or a stacked structure thereof can be used. Note that when a plasma treatment insulating film is formed on the surfaces of the semiconductor layers 4013 and 4014 by performing plasma treatment on 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 treatment insulating film is formed of a rare gas (He, Ne, Ar, Kr,
Including at least one of Xe). Further, the plasma treatment can be similarly performed under the above-described conditions.

Alternatively, the insulating film 4016 may be oxidized by once 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. An insulating film obtained by performing plasma treatment is denser and has fewer defects such as pinholes than an insulating film formed by a CVD method or a sputtering method, so that characteristics of the thin film transistor can be improved.

Next, a gate electrode 4017 is formed (FIG. 48F). The gate electrode 4017 can be formed by a known means (a sputtering method, an LPCVD method, a plasma CVD method, or the like).

In the transistor 4001, the semiconductor layer 4015 used as the source region and the drain region can be formed by performing impurity doping after the gate electrode 4017 is formed.

In the transistor 4002, by performing impurity doping after forming the gate electrode 4017, a semiconductor layer 4013 used 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.

In the transistor 4003, impurity doping is performed after forming the gate electrodes 4017a and 4017b, whereby 4014 used as an LDD region and the semiconductor layer 4013
A semiconductor layer 4015 used as a source region and a drain region can be formed.

In the transistor 4004, a side wall 4021 is provided on the side surface of the gate electrode 4017.
4014 used as an LDD region by performing impurity doping after forming
A semiconductor layer 4013 and a semiconductor layer 4015 used as a source region and a drain region can be formed.

Note that silicon oxide (SiOx) or silicon nitride (SiNx) can be used for the side wall 4021. 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 anisotropic. Silicon oxide (
A method of etching a (SiOx) or silicon nitride (SiNx) film can be used. In this way, only silicon oxide (SiOx) or silicon nitride (S
iNx) film can be left, and 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, so that the transistor 4005 is used as an LDD (Loff) region.
14, a semiconductor layer 4013, and a semiconductor layer 4015 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, whereby a semiconductor layer 4015 used as an LDD (Lov) region and a semiconductor layer 4015 used as a source region and a drain region are formed. it can.

Next, an insulating film 4018 is formed (FIG. 48G). The insulating film 4018 is formed by silicon oxide (SiOx), silicon nitride (SiNx) by a known means (sputtering method, plasma CVD method, etc.).
, Silicon oxynitride (SiOxNy) (x> y), silicon nitride oxide (SiNxOy) (x> y)
A single-layer structure of a film containing carbon such as an insulating film containing oxygen or nitrogen, such as DLC (diamond-like carbon), or a stacked structure thereof can be used.

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 treatment insulating film is formed of a rare gas (He, Ne, Ar, Kr,
Including at least one of Xe). Further, the plasma treatment can be similarly performed under the above-described conditions.

Next, an insulating film 4019 is formed (FIG. 48A). The insulating film 4019 is formed by known means (sputtering method, plasma CVD method or the like) using silicon oxide (SiOx) or silicon nitride (SiNx).
, Silicon oxynitride (SiOxNy) (x> y), silicon nitride oxide (SiNxOy) (x> y)
In addition to an insulating film containing oxygen or nitrogen such as DLC (diamond like carbon), a film containing carbon such as epoxy, polyimide, polyamide, polyvinyl phenol, 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 a siloxane resin corresponds to a resin including a Si—O—Si bond. Siloxane has a skeleton structure formed of 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. 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 a substituent. The plasma processing insulating film contains a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) used for the plasma processing. For example, when Ar is used, the plasma processing insulating film is used. Ar is contained in the film.

In the case where an organic material such as polyimide, polyamide, polyvinyl phenol, benzocyclobutene, 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, whereby the insulating film Can be modified. By modifying the surface, the strength of the insulating film 4019 is improved, and it is possible to reduce physical damage such as generation of cracks at the time of opening formation or the like and film reduction at the time of etching. In addition, 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, in the case where siloxane resin is used as the insulating film 4019 and nitridation is performed using plasma treatment, the surface of the siloxane resin is nitrided to form a plasma treatment insulating film containing nitrogen or a rare gas, and the physical strength is increased. improves.

Next, in order to form the conductive film 4023 electrically connected to the semiconductor layer 4015, the insulating film 4
019, contact holes are formed in the insulating film 4018 and the insulating film 4016. Note that the shape of the contact hole may be a tapered shape, and by using such a shape, the conductive film 4
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 functions 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 the gate electrode of the transistor 4120.
The conductive layer 4104 includes a portion functioning as the first electrode of the capacitor 4121. As the first conductive layer, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, P
t, Si, Zn, Fe, Ba, Ge, or an alloy thereof can be used. 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 functions 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 a silicon oxide film is preferably used as the second insulating film 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 the case where the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as the second insulating film in a portion 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 a part of the second insulating film which is formed so as to overlap with the first conductive layer. A part of the semiconductor layer is extended to a portion of the second insulating film that is not formed so as to overlap the first conductive layer. The semiconductor layer includes a channel formation region (a 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 an LDD region of the transistor 4120. Note that the LDD region 4108 and the LDD region 4109 are not necessarily required. 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 the second electrode of the capacitor 4121.

A third insulating film (insulating film 4111) is formed on the entire surface. Part of the third insulating film includes
A contact hole is selectively formed. The insulating film 4111 functions as an interlayer film. As the third insulating film, an inorganic material (silicon oxide, silicon nitride, silicon oxynitride, etc.) or an organic compound material having a low dielectric constant (photosensitive or non-photosensitive organic resin material)
Etc. can be used. Alternatively, a material containing siloxane can be used. Siloxane is a material in which a skeleton structure is formed by a bond of silicon (Si) and oxygen (O). An organic group containing at least hydrogen as a substituent (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 a substituent.

A second conductive layer (conductive layer 4112) is formed over the third insulating film. Conductive layer 4112
Is 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 an alloy thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

Note that as a step after the second conductive layer is formed, various insulating films or various conductive films may be formed.

Next, the structure of the transistor and the capacitor in the case where an amorphous silicon (a-Si: H) film is used for the semiconductor layer of the transistor will be described.

FIG. 50 illustrates 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 functions 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 the first insulating film is not necessarily formed. In this case, the number of processes 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.
) Is 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 includes the transistor 422.
A portion functioning as the other of the zero source electrode and the drain electrode is included. Conductive layer 420
5 includes a portion functioning as the first electrode of the capacitor 4221. As the first conductive layer, 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 layer 4203 and the conductive layer 4204. The semiconductor layer 4206 includes a portion functioning as one electrode of a source region and a drain region. The semiconductor layer 4207 includes a portion functioning as the other electrode of the source region and the drain region. Note that as the first semiconductor layer, silicon containing phosphorus or the like can be used.

A second semiconductor layer (semiconductor layer 4208) is formed between the conductive layer 4203 and the conductive layer 4204 and over the first insulating film. Part of the semiconductor layer 4208 extends to 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. As the second semiconductor layer,
An amorphous semiconductor layer such as amorphous silicon (a-Si: H) or a semiconductor layer such as a microcrystalline semiconductor (μ-Si: H) can be used.

A 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 insulating film 4210). The second insulating film functions 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 a silicon oxide film is preferably used as the second insulating film 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 the case where the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as the second insulating film in a portion 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 the gate electrode of the transistor 4220.
The conductive layer 4212 functions as the second electrode or the wiring of the capacitor 4221. As the second conductive layer, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, A
u, Pt, 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.

Note that as a step after the second conductive layer is formed, various insulating films or various conductive films may be formed.

FIG. 51 illustrates a cross-sectional structure of an inverted staggered (bottom gate) transistor and a cross-sectional structure of a capacitor. In particular, the transistor illustrated 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 functions 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 the first insulating film is not necessarily formed. In this case, the number of processes 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 the gate electrode of the transistor 4320.
The conductive layer 4304 includes a portion functioning as the first electrode of the capacitor 4321. As the first conductive layer, Ti, Mo, TB, Cr, W, Bl, Nd, Cu, Bg, Bu, P
t, NA-Si, Zn, Fe, Ba, Ge, 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 functions 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 a silicon oxide film is preferably used as the second insulating film 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 the case where the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as the second insulating film in a portion in contact with Mo. This is because the silicon oxide film does not oxidize Mo.

The first semiconductor layer (semiconductor layer 43) is formed on a part of the second insulating film which overlaps with the first conductive layer by a photolithography method, an inkjet method, a printing method, or the like.
06) is formed. A part of the semiconductor layer 4306 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 4306 is
A portion functioning as a channel region of the transistor 4320 is included. The semiconductor layer 430
6 may be a non-crystalline semiconductor layer such as amorphous silicon (A-Si: H) or a semiconductor layer such as a microcrystalline semiconductor (μ-Si: H).

A second semiconductor layer (semiconductor layer 4307 and semiconductor layer 4308) is formed over part of the first semiconductor layer.
Is formed. The semiconductor layer 4307 includes a portion that functions as one electrode of a source region and a drain region. The semiconductor layer 4308 includes a portion functioning as the other electrode of the source region and the drain region. Note that as the second conductor layer, silicon containing phosphorus or the like can be used.

A second conductive layer (a conductive layer 4309, a conductive layer 431) is formed over the second semiconductor layer and the second insulating film.
0 and conductive layer 4311). 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 the second electrode of the capacitor 4321. As the second conductive layer, 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 as a step after the second conductive layer is formed, various insulating films or various conductive films may be formed.

Here, an example of a process characterized by a channel etch transistor will be described. The first semiconductor layer and the second semiconductor layer can be formed using the same mask. In particular,
The first semiconductor layer and the second semiconductor layer are continuously formed. The first semiconductor layer and the second semiconductor layer are formed using the same mask.

Another example of a process characterized by a channel etch 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 under the removed second semiconductor layer becomes a channel region of the transistor.

FIG. 52 illustrates a cross-sectional structure of an inverted staggered (bottom gate) transistor and a cross-sectional structure of 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 functions 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 the first insulating film is not necessarily formed. In this case, the number of processes 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 the gate electrode of the transistor 4420.
The conductive layer 4404 includes a portion functioning as the first electrode of the capacitor 4421. As the first conductive layer, Ti, Mo, Ta, Cr, W, Al, Nd, Cu, Ag, Au, P
t, Si, Zn, Fe, Ba, Ge, or an alloy thereof can be used. 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 functions 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 a silicon oxide film is preferably used as the second insulating film 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 the case where the second insulating film is in contact with Mo, it is desirable to use a silicon oxide film as the second insulating film in a portion in contact with Mo. This is because the silicon oxide film does not oxidize Mo.

The first semiconductor layer (semiconductor layer 44) is formed on a part of the second insulating film which overlaps with the first conductive layer by a photolithography method, an inkjet method, a printing method, or the like.
06) is formed. 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 includes
A portion functioning as a channel region of the transistor 4420 is included. Note that the semiconductor layer 440
For example, a semiconductor layer having an amorphous property 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 over 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 over part of the first semiconductor layer and part of the third insulating film.
7 and semiconductor layer 4408). 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 as the second conductor layer, silicon containing phosphorus or the like can be used.

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 includes the capacitor element 44
21 including a portion functioning as the second electrode. As the second conductive layer, Ti, Mo
, Ta, Cr, W, Al, Nd, Cu, Ag, Au, Pt, Si, Zn, Fe, Ba, G
e or an alloy thereof can be used. Alternatively, a stack of these elements (including alloys) can be used.

Note that as a step after the second conductive layer is formed, various insulating films or various conductive films may be formed.

Here, an example of a process characterized by a channel protection transistor will be described. The first semiconductor layer, the second semiconductor layer, and the second conductive layer can be formed using the same mask.
At the same time, a channel region can be formed. Specifically, the first semiconductor layer is formed,
Next, a third insulating film (channel protective film, channel stop film) is formed using a mask,
Next, a second semiconductor layer and a second conductive layer are successively 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 in which the third insulating film is formed above) becomes the channel region.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (may be a part) described in each drawing of this embodiment are applied to and combined with the contents (may be a part) described in the drawings of another embodiment and examples. Or can be freely replaced. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each embodiment with a portion of another embodiment and an example.

Note that in this embodiment, the contents described in other embodiments and examples (may be a part)
Example when embodied, example when slightly modified, example when partially changed, example when improved, example when described in detail, example when applied, example with 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 this embodiment, an example of an electronic apparatus 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, a display panel 4501 includes a pixel portion 4503 and a scan line driver circuit 4504.
And a signal line driver circuit 4505. For example, a control circuit 4506, a signal dividing circuit 4507, and the like are formed on the circuit board 4502. The display panel 450
1 and the circuit board 4502 are connected by a 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 some peripheral driver circuits (a driver circuit having a low operating frequency among a plurality of driver circuits) are formed over a substrate using transistors, and another peripheral driver circuit (a plurality of driver circuits) is formed. A driving circuit having a high operating frequency may be formed on 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 using TAB (Tape Auto Bonding) or a printed board. Alternatively, all peripheral drive circuits may be formed on an IC chip, and the IC chip may be mounted on the display panel using 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, the cost can be reduced by using a transistor having the same conductivity type as a transistor included in the pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

A television receiver can be completed with such a display module. FIG.
It is a block diagram which shows the main structures of a television receiver. A tuner 4601 receives video signals and audio signals. The video signal includes a video signal amplifying circuit 4602, a video signal processing circuit 4603 that converts a signal output from the video signal into a color signal corresponding to each color of red, green, and blue, and the video signal as input specifications of the drive circuit. Processing is performed by a control circuit 4506 for conversion.
The control circuit 4506 outputs a signal to each of the scan line side and the signal line side. 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 divided into positive integers) and supplied.

Of the signals received by the tuner 4601, the audio signal is sent to the audio signal amplifier circuit 4604, and the output is supplied to the speaker 4606 via the audio signal processing circuit 4605. The control circuit 4607 receives control information on the 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.

A television receiver incorporating a display panel module different from that shown in FIG. 54 is shown in FIG.
Shown in A). In FIG. 55A, a display screen 4702 housed in a housing 4701 is
It is formed of a display panel module. Note that a speaker 4703 and an operation switch 4704 are provided.
Etc. may be provided as appropriate.

FIG. 55B illustrates a television receiver that can carry only a display wirelessly.
A housing 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 a charger 4710. The charger 4710 can transmit and receive a video signal, and can transmit the video signal to a 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 bidirectional 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 transmitted 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 can be performed. It may be a general purpose remote control device. 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. A display panel 4801 includes a pixel portion 4803 provided with a plurality of pixels,
The pixel includes a first scan line driver circuit 4804, a second scan line driver circuit 4805, and a signal line driver circuit 4806 for supplying a video signal to a selected pixel.

A printed wiring board 4802 includes 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
Etc. are provided. The printed wiring board 4802 and the display panel 4801 are connected by a flexible wiring board (FPC) 4813. Flexible wiring board (FPC)
The 4813 is provided with a storage capacitor, a buffer circuit, etc., generating noise in the power supply voltage or signal,
In addition, the signal rise time may be prevented from increasing. The controller 4807
, A voice processing circuit 4811, a memory 4809, a central processing unit (CPU) 4808, a power supply circuit 4810, and the like are displayed on a display panel 480 using a COG (Chip On Glass) method.
1 can also be implemented. The scale of the printed wiring board 4802 can be reduced by the COG method.

Various control signals are input / output via an interface (I / F) unit 4814 provided on the printed wiring board 4802. An antenna port 4815 for transmitting and receiving signals to and from the antenna is provided on the printed wiring board 4802.

FIG. 56B is a block diagram of the module shown in FIG. This module includes a VRAM 4816, a DRAM 4817, and a flash memory 48 as a memory 4809.
18 etc. are included. In the VRAM 4816, the data of the image to be displayed on the panel is DR.
The AM4817 stores image data or audio data, and the flash memory stores various programs.

The power supply circuit 4810 includes a display panel 4801, a controller 4807, a central processing unit (CP
U) Power to operate 4808, the audio processing circuit 4811, the memory 4809, and the transmission / reception circuit 4812 is supplied. However, depending on the specifications of the panel, the power supply circuit 4810 may be provided with a current source.

A 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.
Interface (I / F) section 4819 and the like. 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 an operation based on the input signal and designates 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. Based on the input signal, the control signal generation circuit 4820 generates a signal including various instructions, and a location designated by the arithmetic circuit 4823, specifically, the memory 480.
9, the data is transmitted to the transmission / reception circuit 4812, the audio processing circuit 4811, the controller 4807, and the like.

The memory 4809, the transmission / reception circuit 4812, the audio processing circuit 4811, and the controller 4807 operate according to the received commands. The operation will be briefly described below.

A signal input from the input unit 4825 is sent to a central processing unit (CPU) 4808 mounted on a printed wiring board 4802 via an interface (I / F) unit 4814.
The control signal generation circuit 4820 is an input means 4 such as a pointing device or a keyboard.
In accordance with 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 the specifications of the panel, and supplies the processed signal to a display panel 4801. 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 controller 4807 generates an Hsync signal, a Vsync signal, a clock signal CLK, an AC voltage (AC Cont), A switching signal L / R is generated,
This 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. Specifically, an isolator, a band pass filter, a VCO (Voltage) are processed.
Controlled Oscillator), LPF (Low Pass Filt)
er), couplers, baluns, and other high-frequency circuits. A signal including audio information among signals transmitted and received in the transmission / reception circuit 4812 is sent to the audio processing circuit 4811 in accordance with a command from the central processing unit (CPU) 4808.

A signal including audio information sent in accordance with a command from the central processing unit (CPU) 4808 is demodulated into an audio signal by an audio processing circuit 4811 and sent to a speaker 4827. The audio signal sent from the microphone 4826 is modulated in the audio processing circuit 4811 and sent to the transmission / reception circuit 4812 in accordance with a command from the central processing unit (CPU) 4808.

A controller 4807, a central processing unit (CPU) 4808, a power supply circuit 4810, an audio processing circuit 4811, and a memory 4809 can be mounted as a package of this embodiment.

Of course, the present embodiment is not limited to a television receiver, and is used for various applications as a display medium with a particularly large area such as a monitor of a personal computer, an information display board at a railway station or airport, and an advertisement display board in a street. Can be applied.

Next, a configuration example of the mobile phone according to the present invention will be described with reference to FIG.

A display panel 4901 is incorporated in a housing 4930 so as to be detachable. Housing 493
0 can be appropriately changed in shape or size in accordance with the size of the display panel 4901. A housing 4930 to which a display panel 4901 is fixed is fitted into a printed circuit board 4931 and assembled as a module.

The display panel 4901 is connected to the printed board 4931 through the FPC 4913. A printed circuit board 4931 includes a speaker 4932, a microphone 4933, and a transmission / reception circuit 49.
34, a signal processing circuit 4935 including a CPU and a controller is formed. Such a module is combined with an input means 4936 and a battery 4937 to form a housing 493.
9 is stored. The pixel portion of the display panel 4901 is arranged so that it can be seen from an opening window formed in the housing 4939.

In the display panel 4901, a pixel portion and some peripheral driver circuits (a driver circuit having a low operating frequency among a plurality of driver circuits) are formed over a substrate using transistors, and some peripheral driver circuits (a plurality of driver circuits) are formed. A driving circuit having a high operating frequency among the circuits) may be formed over the IC chip, and the IC chip may be mounted on the display panel 4901 with COG (Chip On Glass). Alternatively, the IC chip may be connected to the glass substrate using TAB (Tape Auto Bonding) or a printed circuit board. With such a structure, the power consumption of the display device can be reduced, and the usage time by one charge of the mobile phone can be extended. Cost reduction of the mobile phone can be achieved.

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 information displayed on the display unit. It has a function of controlling processing by various software (programs). Has a wireless communication function. It has a function of making a call with another mobile phone, a fixed phone, or a voice communication device using a wireless communication function. It has a function of connecting to various computer networks using a wireless communication function. It has a function of transmitting or receiving various data using a wireless communication function. The vibrator operates in response to an incoming call, data reception, or alarm. It has a function to generate a sound in response to an incoming call, reception of data, or an alarm. Note that the functions of the mobile phone shown in FIG.
It can have various functions.

A cellular phone shown in FIG. 58 includes a main body (A) 5001 provided with operation switches 5004, a microphone 5005, and the like, 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 by a hinge 5010 so as to be opened and closed. The display panel (A) 5008 and the display panel (B) 5009 are housed in a 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 from an opening window formed in the housing 5003.

In 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 cellular phone 5000. For example, display panel (A) 5
008 can be used as a main screen, and the display panel (B) 5009 can be combined as a sub screen.

The mobile phone according to the present embodiment can be transformed into various modes depending on the function or application. For example, an imaging element 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
The above-described effects can be obtained even when the 9 is housed in one housing. Even if the configuration of the present embodiment is applied to an information display terminal having a plurality of display units, the same effect can be obtained.

The mobile phone shown in FIG. 58 has a function of displaying various information (a still image, a moving image, a text image, 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 information displayed on the display unit. It has a function of controlling processing by various software (programs). Has a wireless communication function. It has a function of making a call with another mobile phone, a fixed phone, or a voice communication device using a wireless communication function. It has a function of connecting to various computer networks using a wireless communication function. It has a function of transmitting or receiving various data using a wireless communication function. The vibrator operates in response to an incoming call, data reception, or alarm. It has a function to generate a sound in response to an incoming call, reception of data, or an alarm. Note that 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 portion of an electronic device. Such electronic devices include video cameras, digital cameras, goggles-type displays, navigation systems, sound playback devices (car audio, audio components, etc.), computers, game devices, portable information terminals (mobile computers, mobile phones, portable games) Image reproducing apparatus (specifically, D) provided with a recording medium.
a device equipped with a display capable of reproducing a recording medium such as a digital Versatile Disc (DVD) and displaying the image).

FIG. 59A shows a display, which includes a housing 5111, a support base 5112, a display portion 5113, and the like. The display shown in FIG. 59A has a function of displaying various information (still images, moving images, text images, and the like) on the display portion. Note that the function of the display illustrated in FIG. 59A is not limited to this, and the display can have a variety of 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
) Has a function of taking a still image. Has a function to shoot movies. It has a function of automatically correcting captured images (still images, moving images). It has a function of storing captured images in a recording medium (externally or built in a digital camera). It has a function of displaying a photographed image on the display unit. Note that the function of the camera illustrated in FIG. 59B is not limited to this, and the camera can have a variety of 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 a variety of information (still images, moving images, text images, and the like).
Is displayed on the display portion. It has a function of controlling processing by various software (programs). It has communication functions such as wireless communication or wired communication. It has a function of connecting to various computer networks using a communication function. It has a function of transmitting or receiving various data using a communication function. Note that the function of the computer illustrated in FIG. 59C is not limited thereto, and the computer can have various functions.

FIG. 59D shows 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. A mobile computer illustrated in FIG. 59D has a function of displaying various information (still images, moving images, text images, and the like) on a display portion. The display unit has a touch panel function. The display unit has a function of displaying a calendar, date or time. It has a function of controlling processing by various software (programs). Has a wireless communication function. It has a function of connecting to various computer networks using a wireless communication function. It has a function of transmitting or receiving various data using a wireless communication function. Note that the function of the mobile computer illustrated in FIG. 59D is not limited to this, and the mobile computer can have a variety of functions.

FIG. 59E shows a portable image reproducing device (eg, a DVD reproducing device) provided with a recording medium. The main body 5151, a housing 5152, a display portion A5153, a display portion B5154, a recording medium (
DVD, etc.) includes a reading unit 5155, operation keys 5156, a speaker unit 5157, and the like. The display portion A 5153 can mainly display image information, and the display portion B 5154 can mainly display character information.

FIG. 59F shows a goggle type display including a main body 5161, a display portion 5162, earphones 5163, and a support 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 display illustrated in FIG. 59F is not limited thereto, and the display can have a variety of functions.

FIG. 59G illustrates a portable game machine, which includes a housing 5171, a display portion 5172, and a speaker portion 51.
73, an operation key 5174, a storage medium insertion portion 5175, and the like. A portable game machine using the display device of the present invention for the display portion 5172 can express vivid colors. FIG. 59 (G)
The portable game machine shown in FIG. 1 has a function of reading a program or data recorded on a recording medium and displaying it on a display unit. It has a function of sharing information by performing wireless communication with other portable game machines. Note that the portable game machine illustrated in FIG. 59G is not limited to this, and can have a variety of 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 unit 518
6, antenna 5187 and the like are included. A digital camera with a television receiver shown in FIG. 59H has a function of shooting a still image. Has a function to shoot movies. It has a function to automatically correct a photographed image. It has a function of acquiring various information from the antenna. It has a function of storing captured images or information acquired from an antenna. It has a function of displaying a captured image or information acquired from an antenna on a display unit. Note that the function of the digital camera with a television receiver illustrated in FIG. 59H is not limited to this, and the digital camera can have a variety of functions.

As shown in FIGS. 59A to 59E, an electronic device according to the present invention includes a display portion for displaying some information. The electronic device according to the present invention can reduce the operation frequency of the circuit by storing the data in the memory when the data is duplicated, so that the power consumption is small 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 according to the present invention is provided integrally with a building. FIG.
Indicates a building including a housing 5200, a display panel 5201, a speaker portion 5202, and the like. Note that reference numeral 5203 denotes a remote control device for operating the display panel 5201.

The display panel 5201 uses the pixel described in the above embodiment. According to the present invention, a display panel with excellent viewing angle characteristics and high display quality can be obtained. Note that cost can be reduced by using a transistor having the same conductivity type as a transistor included in the pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

The display device illustrated in FIG. 60 is provided integrally with a structure, and thus can be installed without requiring a large space.

FIG. 61 shows another example in which the display device according to the present invention is provided integrally with a building. The display panel 5301 is attached integrally with the unit bath 5302 so that the bather can view the display panel 5301 while taking a bath. Information can be displayed on the display panel 5301 by operation of the bather. Therefore, it has a function that can be used as an advertisement or entertainment means.

The display panel 5301 uses the pixel described in the above embodiment. According to the present invention, a display panel with excellent viewing angle characteristics and high display quality can be obtained. Note that cost can be reduced by using a transistor having the same conductivity type as a transistor included in the 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 on the side wall of the unit bus 5302 shown in FIG. For example, it may be provided integrally with a part of the mirror surface or the bathtub itself. Moreover, 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 according to the present invention is provided integrally with a building.
In FIG. 62, the display panel 5402 is curved in accordance with the curved surface of the columnar body 5401. Here, the columnar body 5401 is described as a utility pole.

A display panel 5402 illustrated in FIG. 62 is provided at a position higher than the human viewpoint. By installing the display panel 5402 in a building that is repeatedly forested outdoors such as a utility pole, information can be provided to the unspecified number of viewers via the display panel 5402. Therefore, it is suitable to use the display panel as an advertisement. In addition, since the display panel 5402 can easily display the same image by external control and can easily switch the image, an extremely efficient information display and advertising effect can be expected. The display panel 5
By providing a self-luminous display element in 402, it can be said that it is useful as a display medium with high visibility even at night. In addition, the display panel 5402 is installed on a utility pole to display the display panel 5
It is easy to secure the power supply means 402. In case of an emergency such as a disaster,
It can also be a means to quickly and accurately convey information to the victims.

The display panel 5402 uses the pixel described in the above embodiment. According to the present invention, a display panel with excellent viewing angle characteristics and high display quality can be obtained. Note that cost can be reduced by using a transistor having the same conductivity type as a transistor included in the pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor. Further, an organic transistor provided on a film-like substrate may be used.

In this embodiment, as a building integrated with the display device of the present invention, a wall, a unit bath,
Although the columnar body is illustrated, 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. A display panel 5502 is provided integrally with a vehicle body 5501 of an automobile, and can display on-demand information on 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 display panel 5502 uses the pixel described in the above embodiment. According to the present invention, a display panel with excellent viewing angle characteristics and high display quality can be obtained. Note that cost can be reduced by using a transistor having the same conductivity type as a transistor included in the 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 vehicle body 5501 shown in FIG. 63 but also in various places. For example, you may provide integrally with a glass window, a door, a handle | steering-wheel, a shift lever, a seat, a room mirror, etc. At this time, the shape of the display panel 5502 may be adapted to the shape of what is 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 shows an example in which a display panel 5602 is provided on the glass of a door 5601 of a train car. Compared to conventional paper advertisements, there is an advantage that labor costs required for advertisement switching are not incurred. Further, the display panel 5602 can instantaneously switch the image displayed on the display unit in response to an external signal. Therefore, for example, the display panel image is displayed for each time zone when the customer class of passengers on the train changes. Can be switched.
Thus, more effective advertising effect can be expected by switching images instantly.

FIG. 64B is a diagram showing an example in which a display panel 5602 is provided on 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 provided in a place where it has been difficult to install conventionally, an effective advertising effect can be obtained. In addition, the display device according to the present invention can instantaneously switch the image displayed on the display unit by an external signal, thereby reducing the cost and time that have occurred at the time of advertisement switching, and more flexible. Advertisement operation and information transmission.

Note that the pixel described in the above embodiment is used for the display panel 5602 shown in FIG. According to the present invention, a display panel with excellent viewing angle characteristics and high display quality can be obtained. Note that cost can be reduced by using a transistor having the same conductivity type as a transistor included in the pixel portion or an amorphous semiconductor for a semiconductor layer of the transistor.

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 provided integrally with a strap, a seat, a rail, a floor, and the like. At this time, the shape of the display panel 5602 may be adjusted to 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. 65A is a diagram showing a shape in use when the display panel 5702 is provided on the ceiling 5701 above the seat of the passenger airplane. The display panel 5702 includes a hinge portion 570.
3 is provided integrally with the ceiling 5701, and the expansion and contraction of the hinge portion 5703 enables the passenger to view the display panel 5702 at a desired position. The display panel 5702 can display information when 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 folded.
By storing in 1, it is possible to give consideration to safety during takeoff and landing. Note that the display element of the display panel 5702 can be turned on in an emergency to be used as an information transmission 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, a display panel with excellent viewing angle characteristics and high display quality can be obtained. Note that cost can be reduced by using a transistor having the same conductivity type as a transistor included in the 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. 65 but also in various places. For example, you may provide integrally with a seat sheet, a seat table, an armrest, a window, etc. In addition, a large display panel that can be viewed simultaneously by a large number of people may be installed on the wall of the aircraft. At this time, the shape of the display panel 5702 may be adapted to the shape of what is to be installed.

In the present embodiment, the train car body, the automobile body, and the airplane body are exemplified as the moving body, but the present invention is not limited to these, and motorcycles, automobiles (including automobiles, buses, etc.).
Various things such as trains (including monorails, railways, etc.) and ships 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, the moving body can be prevented by installing the display device according to the present invention on the moving body. It can be used for applications such as advertisement display boards targeting a large number of specific customers and information display boards in the event of a disaster.

In the present embodiment, various drawings have been used, but the contents described in each drawing (
May be applied to, combined with, the content described in another figure (may be part)
Alternatively, replacement can be performed freely. Further, in the drawings described so far, more parts can be formed by combining each part with another part.

Similarly, the contents (may be a part) described in each drawing of this embodiment are applied to and combined with the contents (may be a part) described in the drawings of another embodiment and examples. Or can be freely replaced. Further, in the drawings of this embodiment mode, more drawings can be formed by combining each embodiment with a portion of another embodiment and an example.

Note that in this embodiment, the contents described in other embodiments and examples (may be a part)
Example when embodied, example when slightly modified, example when partially changed, example when improved, example when described in detail, example when applied, example with 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 Scanning 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 scanning line 212 Second transistor 311 Signal line driver circuit 312 Scan line driver circuit 313 Pixel unit 314 Pixel 500 pixel 517 first scanning line 612 second transistor 613 third transistor 620 transistor 621 transistor 821 transistor 920 transistor 1014 transistor 1114 transistor 1200 node 1201 unit 1214 transistor 1223 liquid crystal element 1233 holding capacity Quantity 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 Storage capacitor 1901 Third storage capacitor 1911 Third storage capacitor 1921 Third storage capacitor 1922 Node 1923 Node 1924 Transistor 1931 Third storage capacitor 1932 Node 8300 Wiring 8411 First transistor 1300a Subpixel 1300b Subpixel 1400a Subpixel 1400b Subpixel 1500a Subpixel 1500b Subpixel 1600a Subpixel 1600b Subpixel

Claims (1)

A pixel including a first transistor, a second transistor, a first liquid crystal element, a second liquid crystal element, a first storage capacitor, and a second storage capacitor;
Each of the first liquid crystal element and the second liquid crystal element includes 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 through the first transistor,
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 transistor,
The pixel electrode of the first liquid crystal element is electrically connected to the second wiring through the first storage capacitor,
The pixel electrode of the second liquid crystal element is electrically connected to the second wiring through the second storage capacitor,
Different gate signals are input to the first transistor and the second transistor,
The first wiring has a function of supplying an image signal,
The liquid crystal display device, wherein the second wiring has a function of supplying a potential to the first storage capacitor and the second storage capacitor.

Images