JPH1090668A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a charge/discharge current caused by coupling capacity between electrodes when an active element is driven and to make it high picture quality, low power consumption by arranging at least one among a signal line, a gate line and the active element on a substrate surface of a side opposite to the side provided with a capacitive load. SOLUTION: At least one from among the signal line 4, the gate line 9 and the active element 5 is arranged on an array substrate surface of the side opposite to the side facing on a display medium layer. By such a constitution, since at least one from among the signal line 4, the gate line 9 and the active element 5 is arranged on the array substrate surface of the side far from a liquid crystal layer 6, the coupling capacity among various electrodes due to the liquid crystal layer 6 are reduced. Thus, the charge/discharge current caused by the coupling capacity among various electrodes due to the liquid crystal layer 6 when the active element 5 is driven is suppressed, and the high picture quality, the low power consumption are realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active matrix type display device, and more particularly to a display device with low power consumption represented by a liquid crystal display device.

[0002]

2. Description of the Related Art OA display devices such as personal computers, word processors, and EWS; calculators, electronic books,
Display device for electronic organizer; mobile TV, mobile phone, mobile F
A display device such as an AX places importance on portability and needs to be driven by a battery. Therefore, it is desirable that power consumption be as small as possible. Conventionally, as a thin display device,
A liquid crystal display (LCD), a plasma display, a flat CRT, and the like are known. Among them, the liquid crystal display device is most suitable for the demand for low power consumption and has been put to practical use. Of the liquid crystal display devices, a type in which the display surface is directly viewed is referred to as a direct-view type. The direct-view type liquid crystal display device includes a transmission type in which a light source such as a fluorescent lamp is provided on the back surface as a backlight and a reflection type in which ambient light is used. Among them, the transmissive liquid crystal display device requires a backlight, and is not suitable for reducing power consumption. This is because the power consumption of the backlight is large, and it is difficult to use the backlight for one day using a battery. Therefore, a reflective liquid crystal display device is most widely used as a display for portable information equipment. A simple matrix drive is widely used as a driving method of a reflection type liquid crystal display device.
Since the image quality is deteriorated in the simple matrix driving, active matrix driving is desired.

FIG. 96 shows a sectional structure of a reflection type liquid crystal display device having a conventional structure, in which a counter electrode 2 is arranged on the lower surface of a glass substrate 1, and the array is opposed to the glass substrate 1 with a liquid crystal layer 6 interposed therebetween. A substrate is placed. The array substrate has a silicon oxide film 7 disposed on a glass substrate 8, a gate line 9 is disposed below the silicon oxide film 7, and an amorphous silicon layer (a-Si) 5 is disposed on the upper side. The pixel electrode 3 and the signal line 4 which also function as a reflection plate are disposed therebetween.

In such a conventional structure, as shown in FIG. 96, a signal line 4, a gate line 9, and an a-Si 5 are arranged between a glass substrate 1 and a glass substrate 8. That is, an active element (TFT) is arranged between the glass substrates 1 and 8. In this structure, it is difficult to increase the distance between the signal line 4 and the liquid crystal layer 6 and between the gate line 9 and the liquid crystal layer 6. For example, it is very difficult to increase the thickness of the silicon oxide film 7 to 5 μm or more. is there.

In a reflection type liquid crystal display device using an active element having such a structure, PDLC (polymer dispersed liquid crystal), PCGH (phase change guest host liquid crystal), and PSCT (polymer Stabilized cholesteric texture, TN (twisted nematic) or the like having a relatively high dielectric constant and a high driving voltage are used. Therefore, in the conventional structure, when the signal line 4 and the gate line 9 are driven, the current flows through the coupling capacitance Ccom, s between the counter electrode 2 and the signal line 4 and the coupling capacitance Ccom, g between the counter electrode 2 and the gate line 9. The charge / discharge current is a big problem.

[0006]

In this active matrix drive, since an active element is provided for each pixel, high image quality of the reflection type liquid crystal display device is ensured.
In order to drive an active element, a signal line, a gate line, and an auxiliary capacitance line (hereinafter, referred to as a Cs line) are required.
The coupling capacity between the various electrodes via the liquid crystal layer is relatively large,
Because of the charging / discharging current flowing through the coupling capacitor, the low power consumption performance required for the portable device cannot be sufficiently ensured, and it is difficult to simultaneously achieve both high image quality and low power consumption of the reflective liquid crystal display device. Was.

Therefore, the present invention has been made to solve such a technical problem, and has as its object to provide a display device having high image quality and low power consumption.

[0008]

A display device according to the present invention comprises:
A plurality of signal lines and gate lines arranged on a substrate, an array substrate including at least one signal line and a pixel electrode connected to the one gate line via an active element, and the pixel electrode In a display device including an opposing substrate having an opposing opposing electrode, and a display medium layer disposed between the pixel electrode and the opposing electrode, at least one of the signal line, the gate line, and the active element And the other side is arranged on the surface of the array substrate opposite to the side facing the display medium layer.

With the above configuration, in the display device according to the present invention, at least one of the signal line, the gate line, and the active element is disposed on the array substrate surface far from the liquid crystal layer. The coupling capacitance between various electrodes can be reduced. Therefore, it is possible to suppress a charge / discharge current generated due to a coupling capacitance between various electrodes by the liquid crystal layer when driving the active element, and to provide a display device which realizes high image quality and low power consumption.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a sectional structure of the reflection type liquid crystal display device of the first embodiment, and FIG.
The parts corresponding to are denoted by the same reference numerals.

An opposing electrode 2 is disposed on the lower surface of the glass substrate 1, and an array substrate is disposed opposite the glass substrate 1 with the liquid crystal layer 6 interposed therebetween. The array substrate has a silicon oxide film 7 disposed below a glass substrate 8, and a gate line 9 is disposed between the silicon oxide film 7 and the glass substrate 8. On the side, a pixel electrode 3 and a signal line 4 are arranged with an amorphous silicon layer (a-Si) 5 interposed therebetween. A through hole 10 is formed in the glass substrate 8, and the pixel electrode 3 passes through the through hole 10 and sandwiches the lower amorphous silicon layer (a-Si) 5 on the liquid crystal layer 6 side opposite to the pixel electrode 3. 3 and the signal line 4 are arranged so as to extend to positions corresponding to the TFT active elements where the signal lines 4 are arranged.

In such a structure, the signal line 4 and the liquid crystal layer 6
Further, since the glass substrate 8 is interposed between the Gout line 9 and the liquid crystal layer 6, the mutual distance can be increased. Note that the entirety including the TFT element portion is protected by the protective film PC.

Here, in a reflection type liquid crystal display device using a TFT active element, PDLC (polymer dispersion type liquid crystal), PCGH (phase change guest host liquid crystal), PSCT (polymer stabilization) are used as the liquid crystal material used for the liquid crystal layer 6. A material having a relatively high relative dielectric constant and a high drive voltage, such as docoless relic textur or TN (twisted nematic), is used. However, in the structure of this embodiment, when the signal line 4 and the gate line 9 are driven, the coupling capacitance Ccom, s between the counter electrode 2 and the signal line 4 and the coupling capacitance Ccom, s between the counter electrode 2 and the gate line 9. g becomes smaller,
The charge / discharge current flowing here did not increase, and a low power consumption structure was realized.

The coupling capacitances Ccom, s and Ccom,
Power consumption PL consumed by charging / discharging current flowing through g
The CD is indicated as follows.

PLCD = Ccom, s * fs * Vs2 + Ccom, g * fg * Vg2 (1) where fs: signal line driving cycle Vs: signal line driving voltage fg: gut line driving cycle Vg: gut Line drive voltage. However, the power consumption is for one signal line and one gate line. Therefore, the power consumption P
In order to lower the LCD, according to this embodiment, Cco
m, s. It is effective to lower the values of Ccom and g.

Ccom, s. The values of Ccom and g are shown below.

Ccom, s (Ccom, g) ∝εLC * ε (insulator) * ε0 / (εLC * d (insulator) + ε (insulator) * dLC) (2) where εLC: liquid crystal layer Ε (insulator): relative permittivity of insulator between liquid crystal layer and signal line (gut line) ε0: permittivity of vacuum d (insulator): thickness of insulator dLC: thickness of liquid crystal layer From the equation (2), it is possible to reduce the power consumption PLCD by increasing the thickness d (insulator) of the insulator between the liquid crystal layer 6 and the signal line 4 and the insulator between the liquid crystal layer 6 and the gate line 9 in the denominator. is there.

As described above, in the reflection type liquid crystal display device according to the embodiment shown in FIG. 1, the TFT elements including the signal lines 4 and the gate lines 9 are not arranged between the glass substrates 1 and 8, A TFT element is arranged on the opposite side of the glass substrate 1 (a surface far from the liquid crystal layer 6), and a through hole 10 for supplying a voltage to the pixel electrode 3 is opened in the glass substrate 8, and the TFT element is The signal line voltage is supplied to the pixel electrode 3 through the through hole 10.

Since the thickness of the glass substrate 8 is, for example, about 700 μm, the capacitance Ccom,
s, Ccom, and g are reduced, resulting in power consumption P
LCD becomes smaller. The relative permittivity of the silicon oxide film 7 is about 6.5.

Hereinafter, a method for manufacturing the reflection type liquid crystal display device according to the embodiment of FIG. 1 will be described. In the following description, portions corresponding to those in FIG. 1 are denoted by the same reference numerals.

FIGS. 2 to 18 show a method of manufacturing an array substrate of the reflection type liquid crystal display device according to the embodiment of FIG. FIGS. 2 to 18 show how an array substrate having one TFT and one pixel electrode is made, but actually a plurality of TFTs and pixel electrodes are made at the same time.

The glass substrate 8 of FIG. 2 has not been subjected to any processing yet. In FIG. 3, a gate line material 9a is formed on a glass substrate 8 by a magnetron sputtering method (sputtering) method or the like. In FIG. 4, a gate line 9 as shown in FIG. 4 is formed from a gate line material 9a formed on a glass substrate 8 by using a photolithography technique (lithographic technique). As this lithography technology, for example, “A
nalog 1 integrated Circuit
s, PAUL R.S. GRAY ROBERTG. ME
YER, University of California
rnia, Berkeley "and" Nikkei BP V
A known technology disclosed in "LSI Manufacturing Technology Tokuyama, Hashimoto", etc. can be used.

That is, a photoresist (not shown) is sprayed on the gate line material 9a, a portion corresponding to the gate line 9 is exposed by mask exposure, and the photoresist which is not exposed is removed to remove portions other than the portion corresponding to the gate line 9. The gate line material 9a is exposed, unnecessary gate line material 9a to which the photoresist is not sprayed is removed by etching, and then all the photoresist is removed. By the above operation, the intermediate product shown in FIG. 4 is obtained.
Further, as described later, a Cs line may be formed from the gut line material 9a at the same time as the gate line 9 is formed at this time (reference: Nikkei BP, "Flat panel display 1991-1995"). .

Next, as shown in FIG. 5, a silicon oxide film 7 is formed on the entire surface by a CVD method, and an a-Si layer 5a is formed by a sputtering method. FIG. 6 is a sectional view taken along line 6-6 in FIG. Subsequently, as shown in FIG.
Using lithography technology, other portions are removed except for necessary a-Si5, and an aluminum layer 3a is formed by a sputtering method as shown in FIG. FIG. 9 is a sectional view taken along line 9-9 in FIG.

Next, as shown in FIG. 10, an aluminum film 3b is formed under the glass substrate 8 by a sputtering method to form an array substrate. FIG. 11 is a sectional view taken along line 11-11 of FIG. Then, in a condition preheated to about 400 ° C to avoid deforming the array substrate due to excessive temperature gradients, the through hole 10, such as shown in FIGS. 12 and 13 to rotate the lens unit and the combination array substrate using a C0 ₂ laser, etc. Form. As a technique for drilling through holes 10 in an array substrate, for example,
Application to Production Process-Chapter 3 Akira Kobayashi: Development Company ". A laser other than the CO ₂ laser, for example, an excimer laser may be used as a device for forming a through hole in the array substrate. FIG. 13 shows 13-1 in FIG.
FIG. 3 shows a sectional view taken along line 3.

Subsequently, as shown in FIG. 14, resists 12 and 13 are scattered on both sides of the array substrate, and then unnecessary portions are removed. The array substrate in this state is put into a plating tank, and power supply E is applied to aluminum electrodes 3a and 3b on both sides of the array substrate.
And a plating process is performed. Thereafter, as shown in FIG. 15, when all the resist sprayed on both sides of the array substrate is removed, the aluminums 3a and 3b arranged on both sides of the array substrate are brought into a conductive state by plating.

Next, the aluminum 3a formed on the TFT element side of the array substrate is patterned by lithography to form as shown in FIG. FIG. 17 is a sectional view taken along line 17-17 of FIG. Such plating can make the two surfaces of the array substrate conductive at once through the through holes 10 shown in FIG. 12 at low cost. However, as is clear from FIG. Since it cannot be formed flat, it is difficult to use the aluminum 3b under the array substrate (pixel electrode side) as a pixel electrode as it is.

Therefore, as shown in FIG. 18, the aluminum 3b under the array substrate is planarized by the CMP method. Since this portion becomes the pixel electrode 3 later, if the surface is uneven, the voltage applied to the liquid crystal layer 6 varies, and a clearer image cannot be displayed. T of array substrate
Since the unevenness of the aluminum 3a arranged on the FT side does not affect the quality of the image, the power consumption, and the like, it may be left as it is as shown in FIG.

By the above manufacturing method, the array substrate of the display device according to this embodiment is completed. FIG. 19, FIG.
0 shows the completed array substrate 15. FIG. 19 is a diagram of the array substrate 15 viewed from the TFT 16 side, and FIG. 20 is a diagram of the array substrate 15 viewed from the pixel electrode 3 side.

The capacitance Ccom, s (Ccom, g) of the array substrate having the conventional structure shown in FIG. 96 and the capacitance Ccom, s (Ccom, g) of the array substrate having the structure of the embodiment of the present invention shown in FIG.
g), the capacitance Ccom, s (Ccom, g) of the array substrate having the structure of this embodiment is 0.3% of the capacitance Ccom, s (Ccom, g) of the array substrate having the conventional structure.
This is the capacity value. However, when PCGH is used for the liquid crystal layer 6, εLC = 7, ε (insulator) = 3, d (insulator) = 7
00 μm, dLC = 5 μm. Therefore, according to the present invention, the power consumption of the conventional PLCD = 50 mW is reduced to 0.15 mW. However, fs = fg = 20 kHz
Z, Vs = 20V, and Vg = 40V. Signal line 640
And 480 gate lines, the driving method of the reference "TVJ Journal V01.42, NOI (1988)"
In the case of driving as shown in "Yanagisawa", the power consumption consumed by the capacitors Ccom, s and Ccom, g can be reduced from 6.4 W to 20 mW by the present invention.

In the above embodiment, a TFT has been described as an example of the active element. However, the active element of the present invention is not limited to this.
For example, a diode-type active element, an MIM-type (metal-insulator-metal) active element, or a varistor-type active element may be used.

In the array substrate according to the present invention, FIG.
21, the Cs electrodes 17a and 17b can be provided on both sides of the array substrate 15 as shown in FIG. 21, so that the holding characteristics of the pixel electrode 3 are improved and the frame frequency for driving the TFT element 16 is reduced. Even if lowered, image quality does not deteriorate. Further, the material of the liquid crystal layer 6 may be other than those described above.

As described above in detail, according to this embodiment, at least one of the signal line, the Gut line, and the active element is arranged on the array substrate surface far from the liquid crystal layer. The coupling capacitance between various electrodes can be reduced. Therefore, it is possible to suppress a charge / discharge current generated due to a coupling capacitance between various electrodes by a liquid crystal layer when driving an active element, and to provide a reflective liquid crystal display device which realizes high image quality and low power consumption. it can.

An embodiment in which Cs electrodes are formed on an array substrate will be described below.

FIG. 22 shows a sectional structure of a reflection type liquid crystal display device according to this embodiment, and portions corresponding to those of the above embodiment are denoted by the same reference numerals. In the figure, by arranging the Cs electrode 20 so as to overlap the signal line 4 and the pixel electrode 3 via the silicon oxide film 7,
Cs electrodes can be formed in an array structure applicable to the present invention. Further, as shown by the broken line in FIG.
If the s electrode 20 is arranged so as to be located between adjacent pixel electrodes 3, the Cs electrode 20 can be used as a back metal BM, and the Cs electrode 20 has a reflectance lower than that of the signal line 4. By using the electrode 20, an effect as a back metal BM can be expected. For example, the Cs electrode 20
May be formed of molybdenum tungsten or the like.

A method for manufacturing a reflection type liquid crystal display device having the structure of the embodiment shown in FIG. 22 will be described below. The glass substrate 8 in FIG. 23 has not been subjected to any processing yet. Next Figure 2
In step 4, gate lines and Cs material 9a are formed on the glass substrate 8.
Is formed using a magnetron sputtering method (sputtering) method or the like. In the next step, a gate line 9 and a Cs line 20 are formed from the gate line material 9a formed on the glass substrate 8 using a photolithography technique (lithographic technique) as shown in FIG.

That is, a photoresist (not shown) is scattered on the gate line material 9a, a portion corresponding to the gate line 9 and the Cs line 20 is exposed by mask exposure, and the unexposed photoresist is removed to remove the gate line 9 and Cs
The gate line material 9a other than the portion corresponding to the line 20 is exposed, and unnecessary gate line material 9a to which the photoresist is not sprayed is removed by etching, and thereafter all the photoresist is removed. By the above operation, FIG.
The intermediate product shown in 5 is obtained.

Next, as shown in FIG. 26, a silicon oxide film 7 is formed on the entire surface by a CVD method, and an a-Si layer 5a is formed by a sputtering method. FIG. 27 is a cross-sectional view of FIG.
FIG. 7 shows a sectional view taken along line 7. Subsequently, as shown in FIG. 28, necessary a-Si5
The remaining portion is removed except for, and an aluminum layer 3a is formed by a sputtering method as shown in FIG. FIG. 30 is a sectional view taken along line 30-30 of FIG.

Next, as shown in FIG. 31, an aluminum film 3b is formed on the lower portion of the glass substrate 8 by sputtering to form an array substrate. FIG. 32 is a sectional view taken along line 32-32 of FIG. Then, in a condition preheated to about 400 ° C to avoid deforming the array substrate due to excessive temperature gradients, the through hole 10, such as shown in FIG. 33 and 34 to rotate the lens unit and the combination array substrate using a C0 ₂ laser, etc. Form. FIG. 34 is a cross-sectional view of FIG.
A cross-sectional view taken along line 34 is shown.

Subsequently, as shown in FIG. 35, resists 12 and 13 are scattered on both sides of the array substrate, and thereafter unnecessary portions are removed. Put the array substrate in this state in plating tank 1
9, a voltage difference is generated between the aluminum electrodes 3a and 3b on both surfaces of the array substrate by the power supply E, and plating is performed. Thereafter, as shown in FIG. 36, when all the resist sprayed on both surfaces of the array substrate is removed, the aluminums 3a and 3b arranged on both surfaces of the array substrate are brought into a conductive state by plating.

Next, the aluminum film 3a formed on the surface of the array substrate on the TFT element side is patterned by lithography to form as shown in FIG. FIG. 38 is a sectional view taken along the line 38-38 in FIG. Such a plating process can simultaneously and inexpensively conduct both surfaces of the array substrate through the through holes 10, but as shown in FIG. 38, the upper and lower surfaces of the conducting portion 10 must be formed flat. Therefore, the aluminum 3b on the lower side of the array substrate is planarized by the CMP method as in the above embodiment. Since this portion becomes the pixel electrode 3 later, if the surface is uneven, the voltage applied to the liquid crystal layer 6 varies, and a clearer image cannot be displayed. Aluminum 3a arranged on the TFT side of the array substrate
Since the unevenness does not affect the quality of the image or the power consumption, it may be left as it is as shown in FIG.

The array substrate of the display device according to this embodiment is completed by the above manufacturing method. In this structure, as is apparent from FIG.
a are arranged so as to overlap with each other via the silicon oxide film 7.

In the above embodiment, the pixel electrodes formed on both surfaces of the array substrate 15 through the through holes 10 are connected to the T electrodes.
The FT active element 16 has a structure in which the FT active element 16 is connected to each other. A specific embodiment will be described in detail below.

With the structure in which the TFT active element 16 is formed on the side opposite to the liquid crystal layer 6 (back side active element structure), the charge / discharge current flowing through the coupling capacitor can be drastically reduced, and low power consumption can be realized. Becomes

The back-side active element structure can reduce the power consumption of the reflection type liquid crystal display device. However, in manufacturing, the pixel electrode surface is likely to have irregularities, so that the image quality is deteriorated and the manufacturing process is extremely difficult. Become complicated. Also,
Signal lines, gate lines and integrated circuits (ICs) for driving them
Therefore, a connection region for connecting the frame and the frame must be provided, which hinders the frame area.

The following embodiments provide a reflection type liquid crystal display device having high image quality, low power consumption and small frame area.

In this embodiment, the pixel electrodes 3 and the active elements 16 are connected through the through holes 10 provided in the array substrate 15 and the lead lines 3x
Since the through hole 10 and the pixel electrode 3 are connected via the through hole, the region where the active element 16 is arranged can be made smaller than the region where the pixel electrode 3 is arranged. Therefore, a reflective liquid crystal display device having a small frame area can be provided.

FIG. 39 shows a sectional structure of a reflection type liquid crystal display device according to this embodiment, and the same parts as those in the embodiment of FIG. 1 are denoted by the same reference numerals.

The only difference between the embodiment shown in FIG. 39 and the embodiment shown in FIG. 1 is a lead line 3x connecting between the pixel electrode 3 and the connection portion 3c formed in the through hole 10.
Others have the same configuration. The TFT element 16 supplies the voltage of the signal line 4 to the pixel electrode 3 through the connection portion 3c formed in the through hole 10 and the lead line 3x.

FIGS. 40, 42 and 44 are plan views when the glass substrate 8 is viewed from the liquid crystal layer 6 side.
Is a plan view when the glass substrate 8 is viewed from the silicon oxide film 7 on the opposite side.

In FIG. 40, black circles indicate through holes 10.
And each of the through holes 10 and the corresponding pixel electrode 3 are connected by a lead line 3x. The lead 3x is suitably made of aluminum, ITO, or the like having a small electric resistance.

On the opposite side shown in FIG.
The Gout line 9 and the integrated circuit (IC) are connected by a connection pad 22. In this embodiment, as shown in FIGS. 40 and 41, the area where the TFT active element 16 is arranged (active element area) is smaller in area than the area where the pixel electrode 3 is arranged (pixel electrode area). The connection pad 22 can be provided under the pixel electrode 3.
The specific areas of the active element region and the pixel electrode region and their definitions are shown in FIGS.

FIGS. 42 and 43 show the glass substrate 8 and the IC 24.
a and 24b are connected to each other, and FIG.
And ICs 24a and 24b are film carrier tape 26
Connected through. This connection method is, for example, "TA
A known technique such as "Introduction to Technology B" by Industrial Research Committee by Bezo Hatada, may be used.

As described above, in this embodiment, since the ICs 24a and 24b and the glass substrate 8 can be connected under the pixel electrode 3, it is possible to provide a reflective liquid crystal display device having a small frame area.

FIGS. 44 and 45 show the glass substrate 8 and the IC 24.
a and 24b are connected to each other, and FIG.
And the ICs 24a and 24b are connected by so-called COG mounting connected via bumps (not shown). This connection method is, for example, "Flat panel display
1990-1996 Nikkei BP, etc. ". Also in this case, similarly to FIGS. 42 and 43, it is possible to reduce the frame area of the reflection type EYE display device. The ICs 24a and 24b shown in FIG.
6 may be manufactured during the same manufacturing process. In this case, no connection bump is required.

FIGS. 46 and 47 are diagrams for showing the effect of reducing the frame area according to this embodiment in comparison with the conventional example, and FIG. 46 shows a conventional example. FIG. 47 shows a reflection type liquid crystal display device according to this embodiment. FIG.
In FIG. 7, the through hole 10 is omitted.

In this embodiment, as is apparent from FIG. 47, the active element region can be made much smaller than the pixel electrode region. It is possible to greatly reduce the frame area.

FIG. 48 is an enlarged view showing a connection portion between the through hole 10 and the pixel electrode 3 by the lead line 3x. It is desirable that the line width of the lead wire 3x be as small as possible in terms of manufacturing technology.

Further, in this embodiment, the active element region can be reduced, and the exposure area when forming the active element is reduced, so that the active element can be manufactured more uniformly. The number of shots in the stepper method can be reduced, and high throughput can be realized.

As described above, in this embodiment, the pixel electrodes and the active elements are connected through the through holes provided in the array substrate, and the through holes and the pixel electrodes are connected through the lead lines. Therefore, the region where the active element is arranged can be made smaller than the region where the pixel electrode is arranged. Therefore, a reflective liquid crystal display device having a small frame area can be provided.

The following embodiment relates to a reflection type liquid crystal display device in which a liquid crystal material is sandwiched between a substrate having a reflection surface and a transparent substrate. A pixel electrode is provided on a substrate on the reflection surface side, and a signal provided on the pixel electrode is provided. The connection between the line and the scanning line and the signal line driving circuit and the scanning line driving circuit is performed by using a contact hole provided in the substrate (where the inside of the contact hole is filled with a conductive material. Of the drive circuit IC
Is mounted on the back surface of the substrate, or an array is formed on the back surface of the substrate using polycrystalline silicon or the like, and has a cell-type module configuration.

[0062] Not only portable terminals but also notebook personal computers and the like are desired to have larger panel sizes, while demands for narrower frames are increasing. For example, as shown in FIG. 75, the signal line drive circuit IC 181 is arranged parallel to the long side above the display surface 180, and the scan line drive circuit IC 182 is arranged parallel to the short side on the left side of the display surface. There is a way.
In addition, as for the connection method between each drive circuit IC and the liquid crystal cell, for example, regarding the signal line drive circuit and the signal line, as shown in FIG. 76, the pad portion 186 without the passivation 185 is located outside the cell from the signal line. There is a method of connecting the tab wiring 187 from the signal line driving circuit to the pad portion 186 via an anisotropic conductive film 188. Thus, for example, when there is an IC on the tape carrier, the size of the module becomes at least as large as the width of the tape carrier. Similarly, also in the scanning line driving circuit, the module size is increased by at least the width of the tape carrier on which the scanning line driving circuit is located. As a means for solving this, a method of bending the tape carrier of the signal line drive circuit and bringing it to the back surface of the cell has been performed, but in order to avoid a connection failure due to the bending stress acting on each drive circuit. In addition, it is necessary to allow a certain margin, and the panel size increases by the size. In addition, a gate array (hereinafter referred to as GA) for converting an image signal from a computer, an amplifier circuit for gradation signals (hereinafter referred to as OP), other passive elements, and the like for determining a module size. Active elements are required, and the PC board on which these elements are mounted contributes to determining the module size.

On the other hand, in order to reduce the panel size and the manufacturing process, a technique for forming a signal line driving circuit and a scanning line driving circuit with polycrystalline silicon has been developed. In this case, the cell size can be reduced, but cannot be completely eliminated.

In the embodiment described below, a signal line driving circuit and a scanning line driving circuit are mounted on the back surface of an insulating substrate provided with a pixel electrode having a reflective surface, and the above-described ICs do not increase the panel size. Provided is a reflective liquid crystal display device.

Further, in this embodiment, the wiring length in the cell can be shortened by dividing the cell into pixel blocks composed of a plurality of pixels and driven, and the power consumption can be reduced due to the reduction in the wiring capacitance. Can be reduced.

Further, by dividing the inside of the cell into pixel blocks each composed of a plurality of pixels and driving them, the moving image display section and the still image display section can be driven separately. By increasing the frequency and lowering the drive frequency of the block for displaying a still image, power consumption can be optimized according to the displayed image.

Further, even when the intervals between signal lines and scanning lines are reduced due to high definition, it is possible to increase the intervals between adjacent contact holes by changing the positions where the contact holes are provided in various ways. It is possible to prevent electrical contact between adjacent contact holes.

An array having pixel electrodes is formed on the front surface of an insulating substrate having a reflection surface, and image data is controlled on the back surface of the insulating substrate in addition to the signal line driving circuit and the scanning line driving circuit. Control circuit (eg, GA)
And a processing circuit (for example, a central processing unit; hereinafter, referred to as a CPU) for processing external input data by a desired logic means, and a passive element and an active element (for example, OP) for performing electrical signal conversion. In addition, not only display but also each element required for the information terminal itself can be integrated and constructed.

The liquid crystal display of this embodiment has a transparent insulating substrate sandwiching a liquid crystal material, an insulating substrate, a transparent electrode provided on the transparent insulating substrate, and a reflection surface provided on the insulating substrate. A pixel electrode, a signal line for applying an image signal to the pixel electrode, and a signal line driving circuit for supplying an image signal to the signal line, wherein the signal line and the signal line driving circuit are provided in the insulating substrate. Is basically connected through a contact hole provided in the first embodiment.

A first viewpoint of this embodiment is that a pixel electrode having a reflective surface and a signal line provided with the pixel electrode are arranged on a front surface of an insulating substrate, and a signal line drive for outputting an image signal to the signal line is provided. The circuit is a reflection type liquid crystal display device, which is arranged on the back surface of the insulating substrate, that is, on the back surface of the reflection surface.

A second viewpoint is that a pixel electrode having a reflection surface arranged in a matrix and a switching element provided with the pixel electrode, a signal line and a scanning line are arranged on a front surface of an insulating substrate. A signal line and a scanning line, a signal line driving circuit that outputs an image signal to the signal line, and a scanning line driving circuit that outputs a scanning signal to a scanning line that controls the switching element are provided in a contact hole provided in an insulating substrate. A reflective liquid crystal display device, wherein the reflection type liquid crystal display device is connected through

A third viewpoint is that a pixel electrode having a reflection surface arranged in a matrix and a switching element provided with the pixel electrode, a signal line and a scanning line are arranged on a front surface of an insulating substrate. A signal line and a scanning line, a signal line driving circuit for outputting an image signal to the signal line, and a scanning line driving circuit for outputting a scanning signal to a scanning line for controlling the switching element are provided in a contact hole provided in an insulating substrate. And the signal line driving circuit and the scanning line driving circuit are disposed on the back surface of the insulating substrate, that is, on the back surface of the reflection surface.

A fourth viewpoint is that the pixel electrodes arranged in a matrix on the insulating substrate are divided into pixel blocks each having at least two or more pixels, and the pixel electrodes are arranged in the blocks. On the other hand, a switching element for controlling a write operation, a scanning line for driving the switching element, a scanning line driving circuit for supplying a scanning signal to the scanning line, a signal line for applying an image signal, and a signal line A signal line driving circuit for supplying an image signal, wherein the wiring length of the signal line and the scanning line is the same or not the same for each block, so that the wiring length is changed and the wiring capacitance is changed. A reflection type liquid crystal display device characterized in that a driving frequency can be changed.

A fifth viewpoint is that the pixel electrodes arranged in a matrix on the insulating substrate are divided into pixel blocks composed of at least two or more pixels, and signal lines and scans are made between adjacent blocks. The signal lines and the scanning lines in the block are driven by the same signal line driving circuit and the scanning line driving circuit, or the signal line driving circuit and the scanning line which are not the same. A reflective liquid crystal display device characterized in that the number of each IC is optimized according to the cell size or the number of pixels by being driven by a drive circuit.

In a sixth aspect, by changing the distance between the signal lines or the scanning lines and the distance between the contact holes, the substrate structure adapted to the process conditions for forming the contact holes or the pin width of each IC. A reflective liquid crystal display device characterized by the following.

A seventh viewpoint is that an array having pixel electrodes is formed on the front surface of an insulating substrate having a reflection surface, and an image is formed on the back surface of the insulating substrate in addition to the signal line driving circuit and the scanning line driving circuit. A control circuit that controls data (for example,
GA), a processing circuit (for example, CPU) for processing external input data by desired logic means, a passive element and an active element (for example, 0P) for performing electric signal conversion, not only display but also the information terminal itself A reflection type liquid crystal display device characterized by mounting each of the elements required for the above or mounting any of them.

An eighth viewpoint is that an array having pixel electrodes is formed on the front surface of an insulating substrate having a reflection surface, and an image is formed on the back surface of the insulating substrate in addition to the signal line driving circuit and the scanning line driving circuit. A control circuit that controls data (for example,
GA), a processing circuit (for example, CPU) for processing external input data by a desired logic means, and a passive element and an active element (for example, 0P) for performing electric signal conversion are formed of polycrystalline silicon, monocrystalline silicon or The reflection type liquid crystal display device is characterized in that not only display but also each element required for the information terminal itself is integrated and constructed because it can be formed by a semiconductor composition equivalent thereto.

In the liquid crystal display device of this embodiment,
As a material of the insulating substrate, a glass substrate or the like can be used. However, since a reflecting plate can be provided between the substrate and the liquid crystal cell, the pixel electrode does not need to double as the reflecting plate.
Therefore, the insulating substrate may be a substrate material made of silicon, ceramics, or the like. The reflective material can be made of aluminum, chromium, or the like when it is also required to be electrically conductive as the pixel electrode. Magnesium, barium sulfate, or the like can be used. In the liquid crystal display device, when a color display is performed, the display may be performed by laminating the liquid crystal layers.

According to the first aspect, a pixel electrode having a reflection surface is provided on a signal line, and an image signal to the signal line is supplied to a signal line driving circuit disposed on the back of the insulating substrate, that is, on the back of the reflection surface. Signal line drive circuit,
An image can be displayed, for example, a segment display or a simple matrix display can be performed without lowering the aperture ratio without appearing on the display surface.

According to a second aspect, a pixel electrode having reflective surfaces arranged in a matrix and a signal line driving circuit and a scanning line driving circuit, which are means for applying a voltage to the pixel electrode, comprise an insulating substrate. By connecting via the contact hole provided in the inside, by providing the contact hole inside the cell, the tab wiring part which determines the distance between each IC and the cell can be arranged under the cell. ,
The distance between each IC and the cell can be reduced.

According to a third viewpoint, a pixel electrode having a reflective surface arranged in a matrix and a switching element provided with the pixel electrode, a signal line, and a scanning line are:
The signal line driving circuit and the scanning line driving circuit are arranged on the front surface of the insulating substrate, and are disposed on the back surface of the insulating substrate, that is, the back surface of the reflection surface through the contact holes provided in the insulating substrate, so that tab wiring is not required. Further, the area occupied by each IC can be substantially minimized or set to zero.

According to the fourth viewpoint, the lengths of the signal lines and the scanning lines can be changed appropriately by dividing the pixel electrodes arranged in a matrix into blocks each including a plurality of pixels and driving the blocks. Can be. As a result, the capacity of the signal line and the scanning line can be reduced as compared with the related art, so that the power consumption represented by the following equation (3) can be reduced by reducing the capacity.

P = C * F * V ² (3) where P: power consumption C: capacity F: drive frequency V: drive voltage Also, a multimedia for displaying moving images and still images simultaneously on the same display surface In the correspondence, a driving frequency can be changed between a moving image display block and a still image display block by displaying a moving image in some of the blocks and displaying a still image in the other blocks. Thus, in the block of the still image display, the expression (3)
, The power consumption can be reduced. According to a fifth aspect, between adjacent blocks:
The signal line and the scanning line can be shared or not. For example, the scanning lines may be shared between adjacent blocks and the signal lines may not be shared. By using a common scanning line, the wiring capacity is increased, but the power consumption is not increased because the driving frequency is low. The driving frequency is high in the signal line, but the wiring capacity can be reduced, so that the power consumption can be reduced.

When the polarity inversion is required, the wiring method of the signal line and the scanning line is variously changed,
An optimal block configuration for common inversion and dot inversion can be obtained. This may increase the number of signal line driving circuits and scanning line driving circuits, but since it can be mounted on the back surface of the insulating substrate, the module can be configured without increasing the size.

According to the sixth viewpoint, each contact hole can be enlarged when the interval between adjacent signal lines or adjacent scanning lines is reduced due to high definition. Thus, even when the interval between the contact holes is limited by the process conditions for forming the contact holes, an optimum contact hole can be formed and connected to the wiring. Further, even when the pin interval between the signal line driving circuit and the scanning line driving circuit is limited, the arrangement of the contact holes can be changed according to the pin configuration of the IC.

According to a seventh aspect, a control circuit (eg, a GA) for controlling image data is provided on the back surface of the insulating substrate in addition to the signal line driving circuit and the scanning line driving circuit.
A processing circuit (for example, CPU) for processing external input data by a desired logical embedding means, a passive element and an active element (for example, OP) for performing electrical signal conversion, not only display but also Each element required for the information terminal itself can be mounted. Thereby, each element is arranged on the back of the display surface, and the module size can be made substantially equal to the panel size. This makes it possible to configure an information terminal such as paper, all of which is a display surface.

According to an eighth aspect, in addition to the signal line driving circuit and the scanning line driving circuit, a control circuit (eg, a GA) for controlling image data is provided on the back surface of the insulating substrate.
A processing circuit (for example, a CPU) for processing external input data by a desired logic means; a passive element and an active element (for example, an OP) for performing electrical signal conversion; Can be formed of polycrystalline silicon, single crystal silicon, or a semiconductor composition equivalent thereto. Thus, one or a plurality of insulating substrates having a display surface on which the pixel electrodes are provided and a back surface on which the respective elements are provided can be configured. Therefore, the number of external elements can be minimized.
Further, since the display surface and the rear surface can be formed by the same process, the manufacturing process can be simplified.

Hereinafter, a detailed description will be given with reference to the drawings.

(First Example) In a first example of this embodiment, a pixel electrode having a reflection surface and a signal line provided with the pixel electrode are arranged on the front surface of an insulating substrate, and an image on the signal line is formed. The signal line driving circuit for outputting a signal is a reflection type liquid crystal display device disposed on the back of the insulating substrate, that is, on the back of the reflection surface.

For example, the reflection type liquid crystal display device shown in FIG. 51 includes a transparent insulating substrate 31 sandwiching a liquid crystal material 33, an insulating substrate 37, a transparent electrode 32 provided on the transparent insulating substrate 31, 37, a pixel electrode 34 having a reflective surface provided at 37, a signal line 35 for applying an image signal to the pixel electrode 34, and a signal line driving circuit 38 for supplying an image signal to the signal line 35, Signal line 35
And the signal line drive circuit 38 are connected through a contact hole 36 provided in the insulating substrate 37. An insulating material 30 is provided between the pixel electrode 34 and the signal line 35 as needed. Here, the conductive material 36a is filled in the contact hole. The pixel electrode 3
4. The material is not particularly distinguished from the conductive material 36a in the signal line 35 and the contact hole 36, as long as the material has conductivity.

The method of applying a voltage to the transparent electrode 32 side is shown in FIG.
As shown in FIG. 2, a contact hole 40 is separately provided, and the transparent electrode 32 and the opposing voltage generating circuit 39 are formed of the conductive material 40a filled in the contact hole 40, similarly to the signal line 35 and the signal line driving circuit 38. It can be implemented by connecting via a PC.

As shown in FIG. 53, when the same counter electrode potential is applied to the transparent electrode 32 for a plurality of pixels disposed in the cell, a conductive portion 41 is provided around the cell. , And the pixel electrode 34 is electrically insulated from the transparent electrode 32. Here, when the pixel electrode 34 and the signal line 35 are configured as a pair,
Segment display can be performed. In addition, the pixel electrode 3
When 4 is the same in one row and the transparent electrodes 32 are the same in one row, simple matrix driving can be performed.

(Second Embodiment) In a second embodiment, as shown in FIG. 54, a transparent insulating substrate 3 sandwiching a liquid crystal material 33 is provided.
1, an insulating substrate 37, a transparent electrode 32 provided on the transparent insulating substrate 31, a pixel electrode 34 arranged in a matrix, a switching element 43 provided with the pixel electrode 34, a signal line 35, and a scanning line. 44, the signal line 35 and a signal line driving circuit (not shown) are connected via a contact hole 36, and the scanning line 44 and the scanning line driving circuit (not shown) are connected via a contact hole 45. Here, the switching element 43 is, for example, a TFT (thin film transistor) element, an MIM (metal insulator element).
Metal) elements and the like. Hereinafter, the switching element will be described using a TFT.

FIG. 55 shows a circuit configuration of the liquid crystal cell according to the embodiment of FIG. Liquid crystal material CLC (33)
, Auxiliary capacitance Cs, and switching element SW (43)
, A signal line Sig, and a scanning line Gate, and the signal line driving circuit and the scanning line driving circuit
It is assumed that they are connected via the signal line contact hole Sc (36) and the scanning line contact hole Gc (45).

FIG. 56 shows a liquid crystal cell according to this embodiment and an example of a module structure relating to the liquid crystal cell in FIG.
7. The contact hole provided in the liquid crystal cell 51, the signal line driving circuit 53 and the scanning line driving circuit 55
(Tape Carrier Package) 52 on which is mounted
And 54 tab wiring pad portions are connected.

(Third Embodiment) In the third embodiment, as shown in FIG. 58, the rear surface of the liquid crystal cell 61 (the display surface is defined) through a plurality of contact holes 62 and 63 provided in the liquid crystal cell 61. The signal line driving circuit 64 and the scanning line driving circuit 65 mounted on the (opposite surface) are connected to the signal lines and the scanning lines. As a mounting method, tab mounting, bump mounting, or the like can be considered. In order to improve the electrical and mechanical contact stability between the drive circuits 64 and 65 and the contact holes 62 and 63, the connection can be sealed with a resin or the like after connection. In addition, stress is applied to the cell and the cell is distorted,
When it is considered that the contact portion is peeled off, an elastic material can be provided around each of the drive circuits 64 and 65.

FIG. 59 shows another embodiment. By providing the contact holes 62 and 63 obliquely with respect to each side of the liquid crystal cell 61 as described above, the drive circuits 64 and 65 can be mounted on the panel. Can be arranged irrespective of the shape.

(Fourth Embodiment) In a fourth embodiment, for example, a plurality of pixel electrodes 34 arranged in a matrix on the insulating substrate 37 of the embodiment of FIG. Is divided into pixel blocks. This liquid crystal cell configuration is shown in FIG.

As shown in FIG. 60, the pixels arranged in a matrix are divided into four pixel blocks PB1 to PB4.
4 and the scanning line driving circuit 65 are connected to the respective pixel blocks PB.
It is assumed that the structure is arranged in the middle of 1 to PB4.

FIG. 61 shows the relationship between the drive circuits 64 and 65 of the liquid crystal cell according to the present embodiment and the configuration of the pixel blocks PB1 to PB4. In this method, the display surface can be driven by being divided into four parts. Therefore, when a moving image and a still image are simultaneously displayed on the same display surface, for example, the moving image is displayed in the display area of the pixel block PB1, and the still image is displayed in the pixel blocks PB2 and PB.
3, by displaying each in the display area of PB4,
The drive frequency of the moving image part and the still image part can be changed.
As a result, the driving frequency in the moving image section is increased (normally 60
Hz), and the driving frequency for a still image can be lowered (for example, using multi-field driving).
Power consumption can be optimized for each PB4.

In this embodiment, since the display surface is divided into blocks and the signal lines and gate lines can be made independent for each block, the signal line capacitance and the scanning line capacitance per drive circuit can be reduced. Can be smaller,
Power consumption can be greatly reduced. Further, in the present embodiment, the wiring length of the gate line can be made shorter than before, so that the image quality deterioration caused by insufficient writing due to gate rounding can be improved, and the wiring length of the signal line can be shortened, so that the signal line and the common electrode Crosstalk caused by the rounding of the rising of the common electrode due to the coupling can be improved.

FIG. 62 shows the signal waveform of the gate rounding and the rising rounding of the common electrode for the conventional system and the present system, respectively. Here, the common electrode can also be divided.

(Fifth Embodiment) In the fifth embodiment, the signal lines and the scanning lines can be shared between the adjacent blocks PB1 to PB4. In the fourth embodiment, the signal lines and the scanning lines are independently arranged in each of the blocks PB1 to PB4. For example, the pixel blocks PB1 and PB2 are common to the scanning lines, and the pixel blocks PB3 and PB4 are shared.
By using the common number 4, the conventional array configuration can be used for the scanning lines. As for the signal line,
Since each block PB1 to PB4 is divided, power consumption can be reduced by reducing the wiring capacity. Further, the signal line driving circuit 64 and the scanning line driving circuit 65 can be shared between the respective pixel blocks PB1 to PB4.

As shown in FIG. 63, a signal line driving circuit 64 and a scanning line driving circuit 65 are provided at the center of the back of the liquid crystal cell 61.
And each of the ICs 64 and 65 can take out pins on both sides. This makes it possible to make the electrical characteristics between the drive circuits 64 and 65 less affected by the display surface. Conventionally, when the screen is divided as shown in FIG. 64, the driving circuits 64 and 65 are provided around the cell 61.
As shown in FIG.
Due to the difference in the electrical characteristics described above, a luminance difference occurred on the display surface, causing display unevenness. In the present embodiment, each driving circuit 6
As shown in FIG. 65, since the difference in electrical characteristics between Nos. 4 and 65 appears around the panel and is driven by the same drive circuit in the center of the panel, display unevenness due to the difference in electrical characteristics does not occur and the image quality can be improved. In addition, display images are different at the top and bottom of the screen, and it is conceivable that crosstalk due to image signals may cause display unevenness at the center of the screen in the past.
In this method, the influence of crosstalk can be reduced, so that display unevenness can be reduced and an area that cannot be visually recognized by visual characteristics can be obtained.

(Sixth Embodiment) In the sixth embodiment, as shown in FIG. 67, the spacing k between the contact holes 132 and the spacing d between the signal lines 131 or the scanning lines are arranged so as not to coincide with each other. Thus, an example in which the distance k between the contact holes 132 can be increased even when the distance d between the wirings is reduced due to higher definition.
As shown in FIG. 67, adjacent contact holes 13
2 are not arranged in a horizontal line but are provided at different levels, so that the distance between the contact holes 132 is larger than the distance d between the wirings. FIG. 68 shows a contact hole 1 in a case where the drive circuits are arranged obliquely as in the third embodiment shown in FIG.
FIG. 3 is a configuration diagram showing an arrangement of the drive circuit 32. By doing so, it is also possible to increase a pin interval of a drive circuit to be connected to the contact hole 132.

FIG. 69 shows still another embodiment. Wiring 13 is provided on both sides of drive circuit 133.
By providing contact holes 132 for every other one, the pin interval is increased. In this case, the relationship between the distance k between the contact holes 132 on the adjacent wiring 131 and the distance d between the signal lines 131 is represented by d ≦ k (4). In this case, k can be arbitrarily determined.

(Seventh Embodiment) In a seventh embodiment shown in FIG. 70, the signal line driving
1 and the scanning line driving circuit 142, a control circuit (for example, GA) for controlling image data, a processing circuit (for example, CPU) for processing external input data by desired logic means, And a passive element and an active element (for example, OP) that perform the above-mentioned operations, and also implements a circuit 146 required for the information terminal equipment, or implements any of them.

FIG. 70 shows a block diagram of a circuit according to the present embodiment. As shown in FIG. 70, when all electric circuits necessary for the information terminal device are mounted on the back of the liquid crystal cell, as shown in FIG. As shown in FIG. 71, a liquid crystal display device 147 in which the frame 148 is extremely thin or hardly occurs can be formed.

(Eighth Embodiment) In an eighth embodiment, an array having pixel electrodes is formed on the front surface of an insulating substrate having a reflective surface, and the signal line driving circuit and the scanning line driving circuit are formed on the back surface of the insulating substrate. In addition to the circuits, a control circuit (for example, GA) for controlling image data, a processing circuit (for example, CPU) for processing external input data by desired logic means, and passive and active elements for performing electrical signal conversion (For example,
OP), not only display but also each element required for the information terminal itself is formed of polycrystalline silicon, single crystal silicon, or a semiconductor composition equivalent thereto, or one of them.

Next, a method of manufacturing the display device according to the above embodiment will be described. As shown in FIG.
An insulating film 155 is formed on the glass substrate 154 on which the TFT 151, the signal line 152, and the scanning line 153 are formed, and a through hole 156 is formed in the insulating film 155 as shown in FIG. 72D, for example, a copper plating column 157 is formed and flattened, a pixel electrode 158 is formed thereon as shown in FIG. 72E, and a liquid crystal 150 is injected between the pixel electrode 158 and the transparent electrode 159. .

Next, a method of forming a contact hole will be described with reference to FIG.
This will be described with reference to FIG. The formation of this contact hole has already been described with reference to FIGS. In FIG. 73 (a), leave preheated to about 400 ° C to avoid deforming the glass substrate 161 due to excessive temperature gradients, in FIG. 73 (a) to rotate the lens apparatus and the combined glass substrate using a C0 ₂ laser, etc. Open contact holes 162 and 163 as shown.

Next, contact holes 162 and 163
Copper plating columns 164 and 165 are formed by plating and lithography technology, and the protruding portions formed at the tips are used as contact portions with the signal line driving circuit and the scanning line driving circuit.

The copper plating process is performed for the contact holes 16.
2, 163 and copper plated pillar 16 on through hole 156
4, 165 can be formed simultaneously.

In the liquid crystal display device according to the eighth embodiment, each element is formed on the back surface of the glass substrate 161. In parallel with the step of forming the TFT provided for the pixel electrode, a dehydrogenation process is performed. Polycrystalline silicon or single-crystal silicon can also be formed by laser annealing or the like.

The method of forming each TFT and the contact hole on the glass substrate has been described above. As shown in FIG. 74, as shown in FIG.
Contact holes 174 and 175 are provided in both the insulating substrate 173 and the insulating substrate 173 arranged separately from the signal line driving circuit 17.
6 and the scanning line driving circuit 177 and other elements 17
8 may be implemented.

As described above, according to this embodiment, the signal lines and the scanning lines provided on the pixel electrodes arranged on the display surface, and the signal line driving circuit and the scanning line as the means for applying a voltage are provided. By connecting the line drive circuit via a contact hole provided in the insulating substrate, an increase in the frame area due to the signal line drive circuit and the scan line drive circuit can be minimized or eliminated. In addition, by dividing and driving into blocks each including a plurality of pixels, the lengths of signal lines and scanning lines can be changed appropriately, so that the capacity of signal lines and scanning lines can be reduced as compared with the related art, and the power consumption can be reduced. Power can be significantly reduced. In the case where a moving image and a still image are simultaneously displayed on the same display surface, a moving image is displayed in some of the blocks, and a still image is displayed in the other blocks. Since the driving frequency can be changed between the image display blocks, the power consumption can be optimized according to the displayed image. In addition, since the signal line driving circuit and the scanning line driving circuit can be shared between adjacent blocks, when one display surface is divided and driven, a difference in electric characteristics of the driving circuit in a display screen occurs. The image quality can be improved so that display unevenness and display unevenness due to crosstalk do not occur. In addition, when polarity inversion is required, by adopting an optimal block configuration for each of signal line inversion, common inversion, and dot inversion, even when the number of signal line driving circuits and scanning line driving circuits increases, insulation is achieved. Since it can be mounted on the back surface of the substrate, it can be configured by variously changing the wiring method of signal lines and scanning lines without increasing the module size. Further, in the case where the interval between adjacent signal lines or adjacent scanning lines is reduced due to higher definition, the interval between contact holes can be increased, so that contact holes can be formed as necessary or sufficiently, and signal line drive can be performed. Even when the pin interval between the circuit and the scanning line driving circuit is limited, the arrangement of the contact holes can be changed according to the pin configuration of the driving circuit. In addition, on the back surface of the insulating substrate, in addition to the signal line driving circuit and the scanning line driving circuit, a control circuit for controlling image data, a processing circuit for processing external input data by a desired logic unit, and performing an electric signal conversion. Since passive elements and active elements, as well as other elements required for the information terminal itself, can be mounted, the module size is almost equal to the panel size, and all are used as a display surface, such as paper. An information terminal device can be configured. In addition, on the back surface of the insulating substrate, in addition to the signal line driving circuit and the scanning line driving circuit, a control circuit for controlling image data, a processing circuit for processing external input data by a desired logic unit, and performing an electric signal conversion. A pixel electrode is provided because passive elements and active elements, as well as other elements required for the information terminal itself as well as the display can be formed of polycrystalline silicon, single crystal silicon, or a semiconductor composition equivalent thereto. One or a plurality of insulating substrates having a display surface and a back surface on which the respective elements are arranged can be configured to minimize the number of external elements, and the display surface and the back surface are formed by the same process. In addition, the manufacturing process can be simplified. In the above embodiments and effects, a liquid crystal display device as an information terminal is taken as an example. However, for example, when a large display device (a large television or an advertising display board, etc.) is configured, a plurality of liquid crystal cells are used. It can be carried out by connecting each liquid crystal cell and providing each driving device mounted on the back surface and each element related to display between adjacent liquid crystal cells. In this case as well, low power consumption, improvement in image quality, simplification of the manufacturing process, and the like can be realized as in the above embodiment.

Here, consider the power consumed inside the liquid crystal panel. FIG. 89 shows a conventional configuration diagram of a liquid crystal display device having a TFT element as a means (hereinafter referred to as an active element) for controlling writing and holding of a display signal for each pixel electrode. In the configuration shown in FIG. 89, a display signal is supplied to the display controller 201, and the signal lines of the LC panel 205 are connected to the upper and lower X drivers (XU) 20 according to the display signal.
2, (XD) 203, and the scanning lines are driven by a Y driver 204.

FIG. 90 shows a conventional diagram of the internal structure of a liquid crystal panel (hereinafter abbreviated as panel) 205 of a liquid crystal display device having a TFT element 205T and a liquid crystal element 205L.

FIG. 91 shows a conventional example of an upper signal line (X) driver circuit 202 for driving a liquid crystal panel 205, for example.

Generally, a liquid crystal device used as a display is represented as a capacitive load in an electric circuit. The power consumed by the panel 205 of the liquid crystal display device shown in FIGS. 89 and 90 is used to charge or discharge the liquid crystal 205L filled in the panel 205. That is, in order to operate the liquid crystal 205L inside the panel 205, charge is applied to the pixel electrode inside the panel 205 to increase the potential of the pixel, or conversely, charge is discharged from the pixel electrode to reduce the potential of the pixel. Power is consumed to set the pixel potential to a desired potential by setting the potential to zero or a combination of charging and discharging to obtain a desired (intermediate state) display characteristic.

Considering the power for charging / discharging the liquid crystal filled in the panel 205, the power is almost completely supplied to the liquid crystal 2 existing on the signal line wired inside the panel 205.
This is the power for charging and discharging 05L. The description is given below. The capacitance of one pixel electrode is Cpix, the dielectric constant of liquid crystal is εLC, the distance from the counter electrode is d, and the area of the electrode is s.
Then, the capacitance of one pixel is represented by Cpix = εLC × (1 / d) × s (5) Here, considering the aperture ratio of the panel 205, that is, the ratio between the pixel electrode and the wiring area inside the panel 205, the aperture ratio is 50% or more in a normal TFT-LCD structure. Assuming 50%
And, assuming that signal line wiring occupies half of the wiring area,
In a panel having a resolution of about VGA (Video Graphics Array: 640 pixels in the horizontal direction × 480 pixels in the vertical direction), the signal line capacitance Csi inside the panel is set.
g is Csig = Cpix × (l / 2) × (1/2) × 640 (6) = 160 × Cpix, and the signal line capacitance Csig is about 160 times the capacitance of one pixel. Therefore, when writing a display signal to one pixel arranged in one row of the panel 205, the signal line driving circuit 202 that supplies the display signal is connected to the signal line connected to the pixel and the capacitance of one pixel. The load CLCD = Cpix + Csig (7) must be charged and discharged. Here, equation (6)
Since Csig >> Cpix (8), it can be said that CLCD ≒ Csig (9). Therefore, the signal line driving circuits 202 and 20
The load of No. 3 mostly depends on the length and area of the signal line in the vertical direction, and the power consumed inside the panel 205 is the power for charging and discharging the liquid crystal 205L existing on the signal line. The power PLCD consumed inside the panel is PLCD = CLCD × fs × (Vs) 2 ≒ Csig × fs × (Vs) 2..., Where Vs is the driving voltage of the liquid crystal and fs is the driving frequency of the signal line. It is represented by (10). In other words, the power consumed by the panel is much larger than the power consumed by the capacitance of one pixel due to the capacitive load of the signal line, but the power consumed by the signal line wired inside the panel However, since the pixel electrode performs the display, the power consumed by the capacitance of the liquid crystal present on the signal line does not contribute to the display image at all. That is, the conventional TFT-LCD structure has a first problem that wasteful power is consumed due to the capacitance of the liquid crystal existing on the signal line.

FIG. 92 is a timing chart showing a conventional driving method of the liquid crystal display device, and FIGS. 93 and 94 show voltage waveforms in the panel at that time. OE (XU) and OE (XD) in the conventional driving method shown in FIG.
And a signal for controlling the output of the upper (XU) and lower (XD) display signal drive circuits (signal line drivers 202 and 203) in the conventional configuration diagram of the liquid crystal display device shown in FIG. , OE (XD) are at the “H” level, and output a display signal to the inside of panel 205.
As shown in FIG. 92, when the display signal is continuously output to the inside of the panel 205 for one frame period _TF , the display signal written to the pixel at the end of the frame period is written to the pixel at the beginning of the frame period. The pixel is more likely to fluctuate than the displayed signal. The voltage waveform inside the panel of FIGS.
FIG. 4 is an example of a display signal in which a frame is composed of n lines;
FIG. 93 (a) shows a drive waveform when a display signal is written to a pixel at the beginning of a frame, and FIG. 94 (a) shows a drive waveform when a display signal is written to a pixel at the last nth line of the frame. Sg shown by a solid line is Tg
A gate signal waveform for driving the gate of the FT element.
sigc is the center potential of the display signal, and + Vsig indicated by a dotted line with Vsigc as the center is a positive display signal, and -Vsig is a negative display signal. Figure 93
FIGS. 93 (a) and 94 (b) correspond to FIGS. 93 (a) and 94 (b), respectively.
(A) shows the pixel potential of the pixel on which writing has been performed. FIGS. 93 (c) and 94 (c) show the difference between the display signal applied to the inside of the panel and the pixel potential, and FIGS. 93 (b) and 94 (b). That is, FIGS. 93 (c) and 94
(C) shows that when the TFT element holds the potential of the pixel,
Voltage (Vd) applied between the source and drain of the FT element
s). Therefore, even when the gate is in the holding state,
When the voltage Vds increases, the current flowing in the channel of the TFT element increases, so that the potential held in the pixel fluctuates. However, as shown in FIGS. 93 (c) and 94 (c), one frame At the beginning and at the end, the voltage Vds applied to the TFT element of the pixel written at the end of one frame
Is longer and longer than the voltage applied to the TFT element of the pixel written first. That is, it can be seen that the potential of the pixel written at the end of one frame is liable to fluctuate, and the display is apt to deteriorate. Therefore, in the conventional liquid crystal display device,
When the holding period is long, crosstalk between the pixel and the signal line occurs due to the magnitude of the voltage applied between the source and the drain of the TFT element, and the display signal displayed on the liquid crystal display device deteriorates. There was a second problem of getting lost.

Further, there is a problem that the area of the driving circuit is increased along with the amount of power consumed by the panel, resulting in an increase in the size of a device incorporating the liquid crystal display device. The problem is that display signals and scanning signals are
This is because the signal line driving circuits 202 and 203 and the scanning signal driving circuit 204 to be supplied to the panel 05 are arranged at the same height as the panel 205. FIG. 95 shows a method of mounting a panel having a conventional structure, a signal line, and a scanning line driving circuit. As shown in FIG. 95, signal lines and scanning line driving circuits 202, 203, and 204
Is TAB (Tape Automated Bondi)
ng) Since the liquid crystal display device is horizontally connected to the panel 205 via the tape 207, the outer shape of the liquid crystal display device is necessarily larger than the area of the panel 205. That is, the driving circuit 2
. 02 are arranged at the same height as the panel 205, there is a problem that the liquid crystal display device is enlarged.

The embodiment described below has been made in view of such a point. In order to reduce the power consumption of the panel, the signal lines inside the panel are divided, that is, the capacitance of the signal lines is reduced. And the divided signal lines are arranged to be driven by independent signal line drivers.
In addition, in order to reduce the power consumed by the signal line itself of the liquid crystal display device, an arrangement distance between the counter electrode and the signal line switching element is set, and in order to reduce their capacitance, a liquid crystal layer and a pixel electrode are used. A signal line, a signal line driving circuit, or both are arranged on the back surface of the substrate. further,
The pixel area where the display signal has changed is individually driven to reduce the number of driving of the pixel electrode and the signal line, equivalently lowering the driving frequency to reduce power consumption, and achieving high quality, low power consumption, small size and light weight. Is provided.

In this embodiment, a pixel electrode having pixel electrodes arranged in a matrix, means for controlling writing and holding of a display signal for each pixel electrode, and means for controlling writing and holding is provided. Means for supplying a display signal to the liquid crystal display device, and when at least one of the signal line drive circuits connected to each of the signal lines is driven when the display signal applied to the liquid crystal display device is in a pause state, Means for electrically opening the other signal lines and the driving circuit connected to the signal lines when in the state, or means for fixing the potential of the signal lines to an arbitrary potential; It is characterized by. When the display signal applied to the liquid crystal display device is in a halt state, or when at least one of the signal line driving circuits connected to each of the signal lines is in a driving state, the other signal lines and Means for electrically opening a drive circuit connected to the signal line or means for fixing the potential of the signal line to an arbitrary potential, and a display signal is applied to a pixel electrode of a liquid crystal display device. When writing data, only the pixel electrode and the signal line driving circuit to which the pixel electrode is connected can be operated. There is no need to charge and discharge a capacitive load that is connected to the power supply, and power consumed inside the liquid crystal panel can be reduced. In particular, the amount of reduction in power consumption for charging and discharging a capacitive load electrically connected to a signal line inside a liquid crystal panel is larger in a large-panel liquid crystal display device. That is, a large-sized liquid crystal display device can be realized with low power consumption.

By operating only the pixel electrode and the signal line driving circuit to which the pixel electrode is connected when writing the display signal, the active element connected between the pixel electrode and the signal line is held. In this case, the voltage difference applied between the active element and the pixel electrode and the fluctuation of the voltage can be reduced, and the leak current of the active element can be reduced. A liquid crystal display device with high image quality can be realized.

Further, by arranging the driving circuit on the back surface, it is possible to reduce the capacitive load applied to the signal lines, to realize a liquid crystal display device with lower power consumption, and to use the driving circuit for the panel. Since it is not necessary to dispose the liquid crystal display device on a frame, a small liquid crystal display device can be realized.

Hereinafter, the present embodiment will be described in detail. FIG. 77 shows a block diagram of a liquid crystal panel of the liquid crystal display device according to the present embodiment. As shown in FIG.
15 is cut by a dashed line at the center of the panel 215 in the column direction. In the liquid crystal display device shown in FIG. 15, the upper signal line driver (XU driver) 212 is connected to the upper half signal line of the panel 215. , Lower signal line driver (X
D driver) 213 is connected to the lower half signal line of panel 215. In addition, XU, XD driver 21
2 and 213, the output of which is high impedance (Hi-
Z) is different from the conventional signal line driver in that it has a function of controlling to the state, and other functions are the same as the conventional.

FIG. 78 is a timing chart for driving the liquid crystal panel and the X drivers 212 and 213 shown in FIG. In the timing chart shown in the figure, _TF indicates a period of one screen (one frame), and in the first half of the period _TF , the XU driver 212 outputs a display signal to a signal line wired to the panel 215, XD in the latter half of _TF
The driver 213 outputs a display signal to a signal line wired to the panel 215. XU212, XD
213 is in the Hi-Z state during the time when the display signal is not output.

FIG. 79 shows a block diagram of X drivers 212 and 213 for driving liquid crystal panel 215 shown in FIG. X drivers 212 and 213 shown in FIG.
Is similar to the conventional X driver except that it has a switch circuit 224 for turning off the signal output to the panel 215 to the signal output circuit.
R) 221, D / A converter 222, output buffer 2
23. The switch circuit 224 is a MOS switch that can be created by a normal IC process, or a C-type switch.
It can be realized by a MOS switch, and does not require any special circuit realization method. Here, the power consumed inside panel 215 when the driving shown in FIG. 78 is performed will be described. The pixel 215L inside the panel 215 is driven at a signal line drive frequency fs for each row (one line) in the row direction, a signal voltage for driving the pixel is Vs, and a capacitance Cs of the signal line is set.
ig, the power Psig consumed by the signal line of the panel 215 is: Psig = Rs × Csig × fs × (Vs) ² (11) Further, the power PLCD consumed by the panel 215 is expressed by the following equation (1).
0), PLCD ≒ Rs × Csig × fs × (Vs) 2 (12) Rs in Expressions (11) and (12) is a ratio between the signal line area of the conventional liquid crystal panel and the signal line area of the liquid crystal panel of the present embodiment. Therefore, in the embodiment shown in FIG. 77, since the area of the signal lines connected to the XU or XD drivers 212 and 213 is の of the panel, Rs = １ ／... (13) Therefore, PLCD ≒ 1/2 × Csig × fs × (Vs) 2...
(14). Here, assuming that the power consumed by the conventional panel expressed by the equation (10) is PCNV, PL
CD ≒ 1/2 × PCNV ··· (1
5) Therefore, according to the present embodiment, the power is reduced to about １ ／ compared to the power consumed by the conventional liquid crystal panel.

FIGS. 80 and 81 show voltage waveforms in the panel when the liquid crystal panel shown in FIG. 77 is driven as shown in FIG. 78. FIG. 80A shows a drive waveform when a display signal is written to a pixel at the beginning of a frame.
(A) shows a drive waveform when a display signal is written to a pixel in the last n-th line of a frame, Sg shown by a solid line is a gate signal waveform for driving the gate of the TFT, and Vsigc is The center potential of the display signal,
+ Vsig indicated by a dotted line centered on Vsigc is a display signal of a positive polarity, and −Vsig is a display signal of a negative polarity. In the display signal waveform shown by the dotted line, "" Hi-
The portion indicated by Z "" indicates that the output signal of the X driver IC shown in FIG. 79 is in the OFF state (Hi-Z state). FIGS. 80 (b) and 81 (b) show the pixel potentials of the pixels to which the writing has been performed in FIGS. 80 (a) and 81 (a), respectively. FIG. 80 (c), FIG. 81
(C) shows the difference between the display signal applied to the inside of the panel and the pixel potential, and FIGS. 80 (b) and 81 (b). In other words, FIGS. 80C and 81C show the voltage (Vds) applied between the source and the drain of the TFT when the TFT holds the potential of the pixel. 80 and 81
As can be seen from the driving waveforms shown in FIGS. 93 and 94, when the output signals of the X drivers 212 and 213 are in the Hi-Z state as compared with the conventional driving waveforms shown in FIGS.
It can be seen that the voltage (Vds) applied between the source and the drain of the first embodiment has become smaller. Further, in the Hi-Z state, there is no change in the voltage applied to the signal line, and therefore, coupling due to the parasitic capacitance between the pixel and the signal line (to the pixel electrode corresponding to the voltage fluctuation of the signal line). Dive)
Is no longer affected. Therefore, according to the present embodiment, T
The voltage Vds of the FT becomes smaller than before, the leak current of the TFT decreases, and the change in the signal voltage written to the pixel can be suppressed to a small value. Further, the influence of the coupling due to the parasitic capacitance between the pixel and the signal line is eliminated, and the change in the signal voltage written in the pixel is suppressed to a small value. That is, since the change in the voltage of the pixel is small, higher image quality can be realized as compared with the related art.

Next, FIG. 82 is a block diagram of a liquid crystal panel of a liquid crystal display device according to a second example of this embodiment. In the panel shown in the embodiment of the same figure, as in the case of the first embodiment, the signal line is divided by 1 /
It is divided into two. The difference from the first embodiment is that a two-terminal nonlinear element 215D is used as an active element. The other parts are the same as the embodiment of FIG. 77, and the description is omitted. FIG. 83 shows a two-terminal nonlinear element 2.
15 shows an equivalent circuit of a pixel electrode portion composed of 15D and a liquid crystal 215L. In the pixel using the two-terminal non-linear element 215D, the voltage difference given from the X driver-212 or 213 and the Y driver-214 is compared with the two-terminal non-linear element 215D.
The liquid crystal is driven by dividing the voltage by the capacitance of 15D and the liquid crystal capacitance of the pixel 215L. Therefore, the display signal Vs ± is applied to the pixel electrode.
After writing Vc, the potential difference between the display signal Vc and the scanning signal Vs is reduced so that the nonlinear element 215D is not turned on, and a constant voltage is set so that the pixel potential does not fluctuate due to the coupling of the nonlinear element 215D by the capacitance CD. Need to be kept. FIG. 84 is a block diagram of an X driver IC for driving the liquid crystal panel 215 of FIG. The X driver IC shown in FIG. 84 has the same configuration as a normal X driver except that the output unit has a switching circuit 224 for switching between a normal display signal output and a constant voltage (VOFF) and outputting the same.

Next, FIG. 85 shows the liquid crystal panel 215 shown in FIG.
84 shows a drive timing chart when driving is performed by the X drivers 212 and 213 in FIG. In the timing chart shown in FIG. 85, XU driver 212 connected to the signal line at the top of panel 215 has one frame period TF
The display signal is output to the inside of the panel 215 during the first half period of the non-linear element 215D.
Is output so as to reduce the potential difference between the display signal VC and the scanning signal VS. XD driver -213 that are connected to the bottom of the panel signal lines outputs a display signal to the internal only panel half period of the latter half of one frame period T _F, the time half the period of the first half nonlinear element 215D A constant voltage VOFF is output so that the potential difference between the display signal VC and the scanning signal VS becomes small so as not to be turned on.

FIGS. 86 and 87 show voltage waveforms inside panel 215 when liquid crystal panel 215 shown in FIG. 82 is operated at the timing shown in FIG. FIG. 86 (a) is a scanning signal waveform when a display signal is written to a pixel at the beginning of a frame, and FIG. 87 (a) is a scanning signal when a display signal is written to a pixel at the last n-th line of the frame. FIG. 86 (b) shows the output signal waveform of the XU driver 212, and FIG. 87 (b) shows the output signal waveform of the XD driver 213. FIG. 86 (c) shows the voltage waveform applied to the pixel according to FIGS. 86 (a) and 86 (b), and FIG. 87 (c) shows FIG.
(A) and (b) show voltage waveforms applied to the pixels. As can be seen from FIGS.
If the C output is at a constant voltage (VOFF),
It can be seen that the potential difference between the display signal Vc and the scanning signal Vs is small, and the signal line voltage is such that the nonlinear element 215D does not turn on after writing the display signal Vs ± Vc to the pixel electrode. Also, when the output of the X driver IC outputs a constant voltage (VOFF), since the AC component of the signal line voltage is small, the nonlinear element 215 of FIG.
It can be seen that it is possible to reduce the fluctuation of the pixel potential due to the coupling between the signal line pixel electrodes due to the capacitance CD of D. Also, the capacitive load of the signal line driven by the X driver in one line writing time (TW) is １ ／ of that of a normal liquid crystal panel which does not divide the signal line.
The power consumption is reduced by half compared to the case of driving the signal lines of a normal liquid crystal panel. Therefore, according to the present embodiment,
A liquid crystal display device with low power consumption and high image quality can be realized.

FIG. 88 shows a timing chart for controlling the output of the X driver when the display image is rewritten only at the upper part of the screen. The partial screen rewriting as shown in FIG. 88 is an effective method for reducing power consumption when movement occurs only in a part of the display screen. If the liquid crystal has a memory property, the XU and XD drivers 212 and 21
By setting the output to Hi-Z for all three, it is possible to further reduce power consumption. In addition, even when driving a liquid crystal having no memory, writing of a moving display portion is performed in a normal frame cycle, and writing of a display portion of a still image only is reduced to half or less of a normal cycle. By doing so, power consumption can be reduced even when driving a liquid crystal having no memory. Switching between the normal output and the Hi-Z output of the output of these display signals is performed for each line and for each pixel, so that more efficient power consumption can be reduced.

Further, further reduction in power consumption can be realized by reducing the capacitive load of the panel. In order to reduce the panel capacity, it is effective to arrange the active elements on the back surface side of the liquid crystal panel and to wire the signal lines, which were conventionally wired inside the panel, on the back surface. In addition, by disposing a driver IC on the back of the panel, the driver I
Since it is not necessary to arrange C in the frame of the panel, the size of the liquid crystal display device can be reduced.

As described above, according to the present embodiment, the signal lines inside the panel are divided, that is, the capacitance of the signal lines is divided, and each divided signal line is driven by an independent signal line driver. When the display signal applied to the liquid crystal display device is in a pause state, or when at least one of the signal line driving circuits connected to each of the signal lines is in the driving state, the other signal lines When a display signal is written to a pixel electrode of a liquid crystal display device, the driver circuit connected to the signal line can be electrically opened or the potential of the signal line can be fixed to an arbitrary potential. Can operate only the pixel electrode and the signal line driving circuit to which the pixel electrode is connected,
This eliminates the need to charge and discharge capacitive loads that are electrically connected to signal lines that are not related to display signal writing inside the LCD panel, thereby reducing power consumption inside the LCD panel. Become. In particular, the amount of reduction in power consumption for charging and discharging a capacitive load electrically connected to a signal line inside a liquid crystal panel is larger in a large-panel liquid crystal display device. That is, the large liquid crystal display device can be driven with low power consumption. Also, when the display signal is written, only the pixel electrode and the signal line driving circuit to which the pixel electrode is connected are operated so that the active element connected between the pixel electrode and the signal line is in the holding state. It is possible to reduce the voltage difference applied between the active element and the pixel electrode and the fluctuation of the voltage, and to suppress the leak current of the active element to a small value. A display device can be realized. Furthermore, by arranging the driving circuit on the back surface, it is possible to reduce the capacitive load on the signal line, and it is possible to realize a liquid crystal display device with lower power consumption, and to arrange the driving circuit on the frame of the panel. Since it is not necessary to perform the operation, the size of the liquid crystal display device can be reduced.

[0138]

As described in detail above, according to the present invention,
Since at least one of the signal line, the gate line, and the active element is arranged on the substrate surface opposite to the side on which the capacitive load is provided, the coupling capacitance between the electrodes when driving the active element is reduced. Therefore, it is possible to suppress a current caused by charging and discharging, and to provide a display device which realizes high image quality and low power consumption.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 3 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 4 is a diagram showing a manufacturing process of the device of FIG. 1;

FIG. 5 is a diagram showing a manufacturing process of the device of FIG. 1;

FIG. 6 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 7 is a diagram showing a manufacturing process of the device of FIG. 1;

FIG. 8 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 9 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 10 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 11 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 12 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 13 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 14 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 15 is a diagram showing a manufacturing process of the device of FIG. 1;

FIG. 16 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 17 is a view showing a manufacturing process of the apparatus of FIG. 1;

FIG. 18 is a diagram showing a manufacturing process of the device of FIG. 1;

FIG. 19 is a top view of the apparatus of FIG.

FIG. 20 is a bottom view of the apparatus of FIG. 1;

FIG. 21 is a sectional view of a liquid crystal display device according to another embodiment of the present invention.

FIG. 22 is a sectional view of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 23 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 24 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 25 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 26 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 27 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 28 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 29 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 30 is a view showing a manufacturing process of the device of FIG. 22;

FIG. 31 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 32 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 33 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 34 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 35 is a diagram showing a manufacturing process of the device shown in FIG. 22;

FIG. 36 is a view showing a manufacturing process of the device of FIG. 22;

FIG. 37 is a diagram showing a manufacturing process of the device in FIG. 22;

FIG. 38 is a diagram showing a manufacturing process of the device of FIG. 22;

FIG. 39 is a sectional view of a liquid crystal display device according to still another embodiment of the present invention.

40 is a top view of the device shown in FIG. 39.

FIG. 41 is a bottom view of the device shown in FIG. 39;

FIG. 42 is a top view of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 43 is a bottom view of the liquid crystal display device according to the embodiment shown in FIG. 42;

FIG. 44 is a top view of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 45 is a bottom view of the liquid crystal display device according to the embodiment of FIG. 44;

FIG. 46 is a side view of a conventional liquid crystal display device.

FIG. 47 is a side view of the liquid crystal display device of the present invention.

FIG. 48 is a plan view showing a part of the liquid crystal display device of the present invention shown in FIG. 39;

FIG. 49 is a top view of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 50 is a bottom view of the device of FIG. 49.

FIG. 51 is a sectional view of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 52 is a sectional view showing a modification of the embodiment in FIG. 51;

FIG. 53 is a sectional view showing still another modification of the embodiment in FIG. 51;

FIG. 54 is a sectional view showing still another modification of the embodiment in FIG. 51;

FIG. 55 is an equivalent circuit diagram of the display device of the embodiment of FIG. 51.

FIG. 56 is a top view of the display device of the embodiment in FIG. 51.

FIG. 57 is a bottom view of the display device of the embodiment in FIG. 51.

FIG. 58 is a diagram showing an example of the arrangement of drive circuits and through holes of the display device according to the embodiment shown in FIG. 51;

FIG. 59 is another example of the arrangement of the drive circuits and through holes of the display device of the embodiment of FIG. 51;

FIG. 60 shows an example of screen division of a liquid crystal display device according to still another embodiment of the present invention.

61 is a layout diagram of a drive circuit in the example of FIG. 60.

FIG. 62 is a diagram showing an output waveform of a drive circuit in the example of FIG. 60 in comparison with a conventional example.

FIG. 63 is a view showing a modification of the arrangement of FIG. 60;

FIG. 64 is a diagram showing an arrangement relationship between a conventional panel and a driving circuit;

FIG. 65 is a diagram showing a state of a display screen by a drive circuit in the example of FIG. 60;

FIG. 66 is a diagram showing a state of a display screen by a driving circuit in a conventional example.

FIG. 67 is a view showing a relationship between wiring and through holes of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 68 is a view showing the relationship between wiring and through holes of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 69 is a view showing the relationship between wiring and through holes of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 70 is a layout diagram of various drive circuits of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 71 is a view showing a state of a picture frame of the apparatus of FIG. 70;

FIG. 72 is a view showing a manufacturing process of the liquid crystal display device according to still another embodiment of the present invention;

FIG. 73 is a view showing a manufacturing process of the liquid crystal display device according to still another embodiment of the present invention;

FIG. 74 shows a configuration of a liquid crystal display device according to still another embodiment of the present invention.

FIG. 75 is a view showing an arrangement relationship between a screen and a drive circuit of a liquid crystal display device according to still another embodiment of the present invention.

76 is a side view of the device shown in FIG. 75.

FIG. 77 is a block diagram of a liquid crystal panel according to still another embodiment of the present invention.

78 is a drive timing chart of the liquid crystal panel shown in FIG. 77.

FIG. 79 is a block diagram showing a configuration of the signal line driver shown in FIG. 77;

FIG. 80 shows a voltage waveform inside the panel shown in FIG. 77.

FIG. 81 shows a voltage waveform inside the panel shown in FIG. 77.

FIG. 82 is a block diagram of a liquid crystal panel according to another embodiment of the present invention.

83 is an equivalent circuit diagram of a pixel portion of the panel shown in FIG. 82

FIG. 84 is a block diagram of a signal line driver according to the present invention.

FIG. 85 is a drive timing chart of the liquid crystal panel according to the present invention.

FIG. 86 shows a voltage waveform inside the panel according to the present invention.

FIG. 87 shows a voltage waveform inside the panel according to the present invention.

FIG. 88 is a drive timing chart of a liquid crystal panel according to still another embodiment of the present invention.

FIG. 89 is a block diagram illustrating a configuration of a conventional liquid crystal display device.

FIG. 90 is a block diagram showing a configuration of a conventional liquid crystal panel.

FIG. 91 is a block diagram of a conventional signal line driver.

FIG. 92 is a drive timing chart of a conventional liquid crystal panel.

FIG. 93 shows a voltage waveform inside a conventional panel.

FIG. 94 shows a voltage waveform inside a conventional panel.

FIG. 95 is a view for explaining the structure of a conventional panel.

FIG. 96 is a cross-sectional view illustrating a structure of a conventional liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Counter electrode 3 ... Pixel electrode 3x ... Lead line 4 ... Signal line 5 ... a-Si 6 ... Liquid crystal layer 7 ... Silicon oxide film 8 ... Glass substrate 9 ... Gate line 10 ... Through hole 13 ... Resist 15 ... Array substrate 16 ... TFT elements 17a, 20 ... Cs electrodes 22 ... Connection pads 24a, 24b ... IC 201 ... Display controller of liquid crystal display device 202 ... Upper signal line driver 203 ... Lower signal line driver 204 ... Scan line driver 221 Shift register for shifting digital display signals 222 D / A converter 223 for converting digital signals to analog signals 223 Output buffer 224 for outputting display signals to signal lines ... Changeover switch for switching ON / OFF of output signal 222A Repel shift circuit for converting a signal to a liquid crystal display voltage 207 A TAB package in which a signal line drive circuit is sealed 205 A glass substrate on which an active element is formed

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruhiko Okumura 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture

Claims (8)

[Claims] An array substrate comprising: a plurality of signal lines and gate lines arranged on a substrate; and a pixel electrode connected to at least the one signal line and the one gate line via an active element. A display device, comprising: a counter substrate having a counter electrode facing the pixel electrode; and a display medium layer disposed between the pixel electrode and the counter electrode, wherein the signal line, the gate line, A display device comprising: the array substrate in which at least one of the active elements is disposed on the array substrate surface opposite to the side facing the display medium layer. 2. An array substrate comprising: a plurality of signal lines and gate lines arranged on a substrate; and a pixel electrode connected to at least one of the signal lines and the one of the gate lines via an active element. A display device comprising: a counter substrate having a counter electrode facing the pixel electrode; and a liquid crystal layer disposed between the pixel electrode and the counter electrode, wherein the signal line, the gate line, and the active A reflection type liquid crystal display device comprising: the array substrate in which at least one of the elements is arranged on the array substrate surface opposite to the side facing the liquid crystal layer. 3. An array substrate comprising: a plurality of signal lines and gate lines arranged on a substrate; and a pixel electrode connected to at least the one signal line and the one gate line via an active element. A display device, comprising: a counter substrate having a counter electrode facing the pixel electrode; and a liquid crystal layer disposed between the pixel electrode and the counter electrode, wherein at least one of the active elements includes the liquid crystal layer. The pixel electrode and the active element are connected to each other through a through-hole provided in the array substrate, and the through-hole and the pixel electrode are connected to each other by a lead line. A reflective liquid crystal display device characterized by the above-mentioned. 4. A transparent insulating substrate sandwiching a liquid crystal material, an insulating substrate, a transparent electrode provided on the transparent insulating substrate, a pixel electrode having a reflective surface provided on the insulating substrate, and the pixel electrode A signal line for applying an image signal to the signal line, and a signal line driving circuit for supplying an image signal to the signal line, wherein the signal line and the signal line driving circuit pass through a contact hole provided in the insulating substrate. A reflective liquid crystal display device being connected. 5. A transparent insulating substrate sandwiching a liquid crystal material, an insulating substrate, a transparent electrode provided on the transparent insulating substrate, and a pixel electrode having a reflective surface arranged in a matrix on the insulating substrate. Switching means for controlling a writing operation to the pixel electrode, a scanning line for driving the switching element, a scanning line driving circuit for supplying a scanning signal to the scanning line, a signal line for applying an image signal,
A signal line driving circuit that supplies an image signal to the signal line, wherein the signal line and the scanning line are connected to each other through a contact hole provided in the insulating substrate, and the signal line driving circuit and the scanning line driving circuit are provided. And a reflection type liquid crystal display device. 6. A pixel electrode arranged in a matrix on an insulating substrate is divided into a pixel block including at least two or more pixels, and a writing operation is controlled for the pixel electrode disposed in the block. Switching means, and a scanning line for driving the switching element,
A scanning line driving circuit for supplying a scanning signal to the scanning line, a signal line for applying an image signal, and a signal line driving circuit for supplying an image signal to the signal line; and the signal line and the scanning line Is connected to the signal line driving circuit and the scanning line driving circuit through a contact hole provided in the insulating substrate. 7. A pixel signal having a matrix arrangement of pixel electrodes, a unit for controlling writing and holding of a display signal for each pixel electrode, and a unit for controlling the writing and holding of a display signal. Supply means for supplying a display signal to the pixel electrode by a signal line divided in the column direction and a signal line drive circuit connected to each signal line and independent in the column direction. A liquid crystal display device characterized by being performed. 8. A divided signal line arranged in an arbitrary column and a signal line driving circuit independent in a column direction connected to each of the signal lines are applied to a liquid crystal display device. When the display signal is in a quiescent state, or when at least one of the signal line driving circuits connected to each of the signal lines is in a driving state, the signal line is connected to the other signal lines and the signal lines. 8. The liquid crystal display device according to claim 7, further comprising means for electrically connecting the driving circuit to an open circuit state.