JPH0764054A - Method for driving liquid crystal display device - Google Patents

Abstract

PURPOSE:To provide a method for driving a liquid crystal display device capable of obtaining an excellent display by sufficiently increasing the voltage applied to a liquid crystal layer without prolonging a selection period and enlarging a current limit value Izmax. CONSTITUTION:The voltage Vin applied to both ends of a series circuit constituted of the liquid crystal layer and a non-linear resistance terminals element is varied from the immediately after time Vss starting the selection period to the immediately before time Vse ending the selection period, and the change of the voltage Vz applied to the non-linear resistance two terminals element in the selection period is made smaller. Thus, when the current limit value Izmax of the non-linear resistance two terminals element is equal to that of using a rectangular wave pulse, a liquid crystal layer applying charge is made larger compared with the case when the rectangular wave pulse voltage is used.

Description

Detailed Description of the Invention

[0001]

The present invention relates to MSM (metal semico)
nductor metal) element, MIM (metal insulator meta)
l) A driving method of a liquid crystal display device having a non-linear resistance two-terminal element such as an element.

[0002]

15 and 16 are plan views of both substrates constituting a general liquid crystal display device using a non-linear resistance two-terminal element. On one insulating substrate 1 shown in FIG. 15, a plurality of scanning signal lines 101 are arranged in parallel, and a plurality of picture element electrodes 104 are formed between adjacent scanning signal lines 101. Further, the non-linear resistance two-terminal element 1 is connected so as to connect each pixel electrode 104 and the corresponding scanning line 101.
03 is formed. On the other insulating substrate 2 shown in FIG. 16, a plurality of data signal lines 102 are formed in a direction perpendicular to the scanning signal lines 101. Both boards 1, 2
Are bonded to each other, and a liquid crystal layer is sealed in the gap to form a liquid crystal display device.

FIG. 17 shows an equivalent circuit of the above liquid crystal display device. In this figure, the liquid crystal layer 105 is represented by a parallel connection circuit of a resistor and a capacitor. Scanning signal line 10
A scan signal 106 as shown in FIG. 18A is applied to 1 and a data signal 107 as shown in FIG. 18B is applied to the data signal line 102. This scanning signal line 1
A difference between the potential of 01 and the potential of the data signal line 102 corresponds to one picture element (hereinafter referred to as a liquid crystal layer portion) of the liquid crystal layer 105 and a non-linear resistance two-terminal element 103. Applied across the circuit.

The scanning signal 106 is divided into a selection period 108 and a non-selection period 109. During the selection period 108, a selection potential that makes the non-linear resistance two-terminal element 103 conductive is taken, and during the non-selection period 109, the non-linear resistance is applied. 2-terminal element 103
A non-selection potential is set to make the non-conducting state. Selection period 108
The potential of b is set to have a polarity opposite to that of the potential of the selection period 108a one cycle before, and the scanning signal 106 drives the liquid crystal layer portion by AC.

The other data signal 107 is set to either one of the two potentials 107a or 107b or an arbitrary potential in the middle thereof when performing binary display of black and white. Here, suppose that black display is performed when the voltage applied to the liquid crystal layer portion is high, and white display is performed when the applied voltage is low (the same case will be described below). A case where black is displayed by increasing the applied voltage is shown, and a case where white is displayed by decreasing the voltage applied to the liquid crystal layer portion is shown in the selection period 108b. In this way, during the selection period 108, an appropriate voltage is applied to the liquid crystal layer portion via the non-linear resistance two-terminal element 103 that is in a conductive state, and during the non-selection period 109, the voltage is held repeatedly. Is displayed.

[0006]

When a scanning signal 106 and a data signal 107 as shown in FIG. 18 are applied, both ends of a series circuit composed of a non-linear resistance two-terminal element 103 and a liquid crystal layer portion. The voltage Vin applied to the liquid crystal layer, the voltage VLC applied to the liquid crystal layer portion, the voltage Vz applied to the non-linear resistance two-terminal element and the current Iz flowing through the non-linear resistance two-terminal element are shown in FIGS. ).

As shown in FIG. 14 (b), Iz becomes maximum immediately after the start of the selection period 108 and then sharply decreases. Generally, a non-linear resistance two-terminal element has a current density Jz with a limit value Jzmax, and when a current of a current limit value Izmax (= Jzmax × S) obtained by multiplying Jzmax by an element area S is applied, the non-linear resistance two-terminal element is provided. Causes dielectric breakdown. Therefore,
The scanning signal 106 and the data signal 10 as shown in FIG.
7 is applied, the maximum current immediately after the start of the selection period needs to be equal to or less than the current limit value Izmax. Note that FIG.
(B) shows the maximum current Izm immediately after the start of the selection period 108.
The case of ax is shown.

Non-linear resistance 2-terminal element 103 during the selection period
The charges applied to the liquid crystal layer portion flowing through
It is represented by the area of the shaded area. The electric charge applied to the liquid crystal layer portion becomes maximum when the maximum current immediately after the start of the selection period is Izmax as shown in FIG. This maximum charge needs to be sufficiently larger than the charge required to light the liquid crystal layer portion (capacitance charge of the liquid crystal layer 105 × required voltage applied to the liquid crystal layer). When Izmax is small and the maximum charge that can be applied to the liquid crystal layer portion is not sufficiently large, the liquid crystal layer portion cannot be lit, so it must be increased.

As a method of increasing the maximum charge, a method of lengthening the selection period can be considered, but this method is not preferable because it is necessary to reduce the number of scanning signal lines. As another method, it is possible to increase the element area S and increase the current limit value Izmax. However, in this case, the amount of charge that can be applied to the liquid crystal layer portion during the selection period increases, and at the same time, the non-linear resistance 2-terminal element 1
Since the current flowing through 03 also increases, the charge lost from the liquid crystal layer 105 during the non-selection period increases. Further, when the element area S is increased, the electrostatic capacitance Cz of the non-linear resistance two-terminal element 103 is increased, so that the following adverse effects are exerted on the driving of the liquid crystal layer 105.

The voltage Vza applied to the non-linear resistance two-terminal element 103 immediately after the start of the selection period is expressed by the following equation (1).

Vza = Vins × CLC / (CLC + Cz) (1) where Vins: voltage applied across the series circuit composed of the non-linear resistance two-terminal element and the liquid crystal layer portion in the selection period CLC; liquid crystal layer Capacitance Cz; Capacitance of Non-Linear Resistance Two-Terminal Element According to the above equation 1, it is understood that as Cz increases, the ratio of Vins applied to the non-linear resistance two-terminal element 103 decreases. This means that in order to increase the element area S and the voltage applied to the non-linear resistance two-terminal element 103 to be the same as before the element area S is increased, it is necessary to increase the voltage Vins. Indicates that there is.

The present invention has been made in order to solve the problems of the prior art, and is applied to the liquid crystal layer without lengthening the selection period or increasing the current limit value Izmax. It is an object of the present invention to provide a driving method of a liquid crystal display device which can obtain a good display by sufficiently increasing the voltage.

[0013]

According to a method of driving a liquid crystal display device of the present invention, each of a plurality of scanning signal lines and a plurality of data signal lines passes through the periphery of picture element electrodes arranged in a matrix. A non-linear resistance two-terminal element, which is arranged in parallel with each scanning signal line and each data signal line and is provided in the vicinity of the intersection of both signal lines, includes the pixel electrode, the scanning signal line, and the data. A pixel signal is connected to a signal line, a scanning signal having a selection period and a non-selection period is applied to the scanning signal line, and a data signal is applied to the data signal line, and the pixel is passed through the non-linear resistance two-terminal element. In a liquid crystal display device in which a voltage is applied to electrodes, a voltage having a gradient in voltage value is applied to both ends of a series circuit composed of a liquid crystal layer portion corresponding to one picture element and the nonlinear resistance two-terminal element. Applied and the two ends of the non-linear resistance during the selection period Since small change in voltage applied to the device, the object is achieved.

In this method of driving a liquid crystal display device, a voltage obtained by modifying a rectangular wave pulse voltage by a circuit including at least a resistor and a capacitor is applied to a voltage applied to both ends of the series circuit during a selection period. can do.

A voltage that changes at a rate of change substantially equal to the voltage applied to both ends of the liquid crystal layer portion during the selection period is applied to both ends of the series circuit during the selection period, and the voltage is applied to the both ends of the selection period during the selection period. The voltage applied to the non-linear resistance two-terminal element may be substantially constant.

[0016]

In the present invention, the voltage Vin applied to both ends of the series circuit composed of the liquid crystal layer portion corresponding to one picture element and the non-linear resistance two-terminal element is a voltage having a gradient in the voltage value during the selection period. Is applied, the nonlinear resistance 2 is applied during the selection period.
The change in the voltage applied to the terminal element becomes small. As a result, compared to the case where the rectangular wave pulse voltage is used, the charges applied to the liquid crystal layer can be increased even if the current limit values of the non-linear resistance two-terminal element are the same.

Further, the voltage Vin applied to both ends of the series circuit during the selection period is changed at a change rate substantially equal to the change rate of the voltage VLC applied to both ends of the liquid crystal layer portion during the selection period. Then, the voltage applied to the non-linear resistance two-terminal element during the selection period becomes substantially constant, and the charge applied to the liquid crystal layer becomes maximum.

Further, a scanning signal may be obtained by blunting the rectangular wave output from the scanning driver by using a circuit in which at least a resistor and a capacitor are combined.
In this case, although it is difficult to obtain the optimum scanning signal waveform, the conventionally used scanning driver can be used as it is, and a special scanning driver is not required.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

In the present invention, the selection period ends immediately after the start of the selection period as shown in FIG. 1A at both ends of the series circuit composed of the liquid crystal layer portion and the non-linear resistance 2-terminal element in the selection period. The Vin changed immediately before is applied. Then, as shown in FIG. 1B, the change in the element current Iz during the selection period becomes small. Therefore, FIG.
Compared to the case of using the rectangular wave pulse voltage shown in (a),
Even if the maximum value of the device current Iz in the selection period is set to be the same as Izmax, the liquid crystal layer applied charge represented by the area of the shaded area in the drawing becomes large.

Further, as shown in FIG. 2A, at a rate of change substantially equal to the rate of change of the voltage VLC applied across the series circuit during the selection period and across the liquid crystal layer portion during the selection period. When the changing voltage Vin is applied, the voltage applied to the non-linear resistance two-terminal element becomes substantially constant during the selection period. In this case, when the maximum value of the device current Iz in the selection period is set to the device current limit value Izmax, the liquid crystal layer applied charge represented by the area of the shaded portion in FIG. 2B can be maximized.

The voltage Vin applied during the selection period
It is necessary that the liquid crystal layer applied charges necessary for display be obtained and that a current exceeding a limit value does not flow through the non-linear resistance two-terminal element. Furthermore, it is desirable that the maximum value of Vin is as small as possible in order to reduce the breakdown voltage required for the driver used to obtain the signal. When the voltage having the waveform as shown in FIG. 1A is used, the voltage Vin applied in the selection period is optimized as follows.

First, as shown in FIG. 2, let us consider a case where display is performed with the highest voltage applied to the liquid crystal layer. here,
The required liquid crystal layer applied voltage is ± VLCb, Vin immediately after the start of the selection period is Vss, Vin immediately before the end of the selection period is Vse, and the rate of change (gradient) of Vin in the selection period is as shown in FIG. To be constant. Further, the current limit value of the non-linear resistance two-terminal element is Izmax, the voltage applied to the non-linear resistance two-terminal element at that time is Vzmax, and the length of the selection period is t.

In this case, the voltage Vzs applied to the non-linear resistance two-terminal element immediately after the start of the selection period is represented by the following two equations.

Vzs = VLCb + Vss × CLC / (CLC + Cz) (2) The above Vss is set to a maximum value, that is, a value such that Vzs is equal to Vzmax. This is to minimize the maximum value Vse of Vin during the selection period. When Vzs is kept at Vzmax during the selection period and the variation amount ΔVLC of the liquid crystal layer applied voltage during the selection period is maximized, ΔVLC = Izmax × t / CLC (3) Vse = Vss + ΔVLC = Vss + Izmax × t / CLC (4) ), And VLC immediately after the selection period is expressed by the following equation (5).

VLC = −VLCb + ΔVLC− (Vse−Vss) × Cz / (CLC + Cz) (5) Since this VLC needs to be VLCb or more, VLC = −VLCb + ΔVLC− (Vse−Vss) × Cz / (CLC + Cz) ) ≧ VLCb ΔVLC ≧ 2VLCb + (Vse−Vss) × Cz / (CLC + Cz) (6). Further, Izmax needs to satisfy the following equation 7 from the above equations 3 and 6.

Izmax ≧ {2VLCb + (Vse−Vss) × Cz / (CLC + Cz)} × CLC / t (7) When the equal sign (=) is satisfied in the above equation 7, Vse is calculated from the above equations 4 and 6. It is set to the value represented by the following eight formulas obtained.

Vse = Vss + 2VLCb + (Vse−Vss) × Cz / (CLC + Cz) (8) When the inequality sign (<) is satisfied in the above equation 7, Vse
Is set to a value represented by the above equation 8, VLC> VLCb immediately after the end of the selection period. Therefore, Vse is set smaller than the value represented by the above equation 8 so that VLC = VLCb. The reason for setting in this way is to reduce the withstand voltage required for the drive signal generation driver as much as possible and to reduce the driver cost.

Next, as shown in FIG. 3, let us consider a case where display is performed in which the voltage applied to the liquid crystal layer is smaller than the maximum value.
As shown in FIG. 3, Vss and Vse are reduced by the same value ΔV as compared with Vss and Vse when the voltage applied to the liquid crystal layer is maximum, and the rate of change (gradient) of Vin in the selection period is made constant. The required voltage applied to the liquid crystal layer can be obtained. In this case, a scanning signal having a constant slope during the selection period as shown in FIG. 4A and a data signal having a constant value in the range of ± Vsig during the selection period as shown in FIG. 4B. Can be used.

Further, as shown in FIG. 5, the gradient is the same as Vss in the case of the display in which the liquid crystal layer applied voltage is the largest and in the case of the display in which the liquid crystal layer applied voltage is smaller than the maximum value, and the opposite gradient to the conventional one. There is a method of obtaining a necessary voltage applied to the liquid crystal layer by changing the voltage by changing Vse by. In this case, as shown in FIG. 6A, the scan signal may be a normal rectangular wave pulse voltage, and the data signal may have an appropriate slope. Further, when the signal shown in FIG. 5 is used, the change in Vz is larger than when VLC is obtained using the conventional signal.

Further, as shown in FIG. 7, a circuit in which a resistor R and a capacitor C are combined is used, and as shown in FIG. 8A, a rectangular wave pulse output from the scan driver (shown by a broken line). The scanning signal (shown by the solid line) may be obtained by blunting. At this time, the data signal shown in FIG.
An ordinary one as shown in (b) can be used.
In this case, when the required liquid crystal layer applied voltage is large, the Vin and VLC waveforms are as shown in FIG. 9A, and when the required liquid crystal layer applied voltage is small, the waveform shown in FIG. Let Vin and VLC waveforms as shown in b). With this method, it is difficult to obtain a scan signal waveform having an optimum change rate, but a scan driver conventionally used can be used. The change in Vz in this case is smaller than that in the case where the conventional signal shown in FIG. 14 is used.

(Embodiment 1) FIG. 10 shows a sectional view of an element side substrate in a liquid crystal display device to which the present invention is applied, and FIG.
FIG. 12 shows a plan view of the element-side substrate, and FIG. 12 shows a plan view of the counter-side substrate which is arranged to face the element-side substrate. As shown in FIGS. 10 and 11, the scanning signal line 5 is provided on the element side substrate.
Are formed. Although only one scanning signal line 5 is shown in the drawing, a plurality of scanning signal lines 5 are actually formed in parallel with the illustrated scanning signal line 5. A plurality of picture element electrodes 8 are provided between adjacent ones of the scanning signal lines 5.
Are formed. Further, the non-linear resistance 2-terminal element 9 is connected so as to connect each pixel electrode 8 and the corresponding scanning signal line 5.
Are formed. The non-linear resistance two-terminal element 9 has a three-layer structure of a Ti thin film 7, a ZnS thin film 6, and a Ta thin film 5.

On the other hand, on the opposite substrate, as shown in FIG. 12, a plurality of stripe-shaped data signal lines 10 are formed in a state intersecting with the above-mentioned scanning signal lines 5, in this example, orthogonal to each other. Has been done.

The element-side substrate and the counter-side substrate are attached to each other with the pixel electrode 8 and the data signal line 10 inside, and the liquid crystal layer is sealed in the gap between them.
A liquid crystal display device is configured.

This liquid crystal display device can be manufactured as follows.

First, on a glass substrate to be a device side substrate,
A Ta thin film is laminated by a sputtering method and patterned by a photolithography method to form a scanning signal line 5.

Next, a ZnS thin film is formed by a sputtering method and patterned by a photolithography method to form a ZnS thin film 6. A Ti thin film is laminated thereon by a sputtering method and is patterned by a photolithography method to form a Ti thin film 7.
This Ti thin film 7, ZnS thin film 6, and scanning signal line 5
The layer structure becomes the non-linear resistance two-terminal element 9.

Further, ITO is formed by the sputtering method.
A thin film of (Indium Tin Oxide) is laminated and patterned by a photolithography method to form a pixel electrode 8. By the above, the element side substrate is completed.

Next, on the glass substrate to be the opposite substrate,
An ITO thin film is formed by a sputtering method and is patterned by a photolithography method to form a stripe-shaped data signal line 10. Through the above steps, the opposite substrate is completed.

These two substrates are attached so that the scanning signal lines 5 and the data signal lines 10 are orthogonal to each other and fixed with a sealing resin, and the gap is filled with liquid crystal to form a liquid crystal layer. With the above, the liquid crystal display device is completed.

After that, the scan driver is connected to the external scanning signal line terminals, the data driver is connected to the external data signal line terminals, and the scanning driver shown in FIG.
The scanning signal shown in FIG. 4A is generated, and the data signal shown in FIG.

In the liquid crystal display device of this embodiment, the capacitance CLC of the liquid crystal layer is 0.8 pF, the required liquid crystal layer applied voltage VLC is 1.0 to 5.0, and the length t of the selection period is 35 × 10 5.
^-6 sec, the electrostatic capacitance Cz of the non-linear resistance 2-terminal element is 0.
2pF, the current limit value Izmax of the non-linear resistance two-terminal element is 2.9 × 10 ⁻⁷ A, and the applied voltage Vzmax at that time is 17V.
Has become.

In such a liquid crystal display device, VLC = 5.
When displaying 0 V, Vss
= 15V and Vse = 27.5V.

At this time, the change amount ΔVLC of the voltage applied to the liquid crystal layer during the selection period is ΔVLC = 1 from the above equation (6).
It becomes 2.5V, and the required non-linear resistance 2-terminal element current is
From the above 7 formula, it becomes 2.9 × 10 ⁻⁷ A. This is equal to the current limit value of the non-linear resistance two-terminal element. Therefore, VLC =
When displaying 5.0V, the above Vss = 15V, V
se = 27.5V is used.

When displaying VLC = 1.0V,
As shown in FIG. 3, a method of reducing Vss and Vse by the same value as Vss and Vse when VLC = 5.0 is displayed was used. At this time, Vss = 8.0V, Vse =
At 20.5V, VLC = 1.0V could be obtained.

As shown in FIG. 4A, the scan signal voltage is Vs1 immediately after the start of the selection period and Vs1 immediately before the end of the selection period.
At s2, the amount of change (gradient) during the selection period is constant and 0 during the non-selection period is used, and as the data signal voltage, as shown in FIG. 4B, the range of ± Vsig is constant. If a value is used, Vss = Vs1 ± Vsig, Vse = Vs
It becomes 2 ± Vsig. Therefore, when VLC = 5.0 is displayed, Vss = 15V and Vse = 27.5V, and VLC = 1.0V
In the case of the display of Vss = 8.0V and Vse = 20.5V, Vs1 = 11.5V, Vs2 = 24.0V, Vsi
g = 3.5V.

According to the driving method of the liquid crystal display device set as described above, the liquid crystal layer is driven by the scanning signal and the data signal shown in FIG. 18 and has a same element current limit value as compared with the conventional liquid crystal display device. The voltage that can be applied to the device was increased, and good display could be obtained.

Although the signals shown in FIGS. 3 and 4 are used in the above-described first embodiment, the signals shown in FIG. 1, the signal shown in FIG. 2, or the signals shown in FIG. 6 are also used in the first embodiment. It can be done using signals.

(Embodiment 2) FIG. 13 is a plan view of an element side substrate in a liquid crystal display device of Embodiment 2. The scanning signal line 5 having the resistance portion 12 and the capacitor portion 13 at the end is provided on the element side substrate, and the resistance portion 12 at the end is provided at the scanning signal line terminal provided outside the display portion on the element side substrate. 11
It is formed in a state of being connected to. This scanning signal line 5
Although one is shown in the illustrated example, a plurality of are actually formed in parallel with the illustrated one. The resistor portion 12 functions as a resistor, and the capacitor portion 13 forms a capacitor with the data signal line on the counter substrate described later.

A plurality of picture element electrodes 8 are formed between adjacent scanning signal lines 5, and each picture element electrode 8 and the corresponding scanning line 5 are formed.
A non-linear resistance two-terminal element 9 is formed so as to connect with. The non-linear resistance two-terminal element 9 includes a Ti thin film 7, Zn
The S thin film 6 and the Ta thin film 5 have a three-layer structure.

Similar to the first embodiment, the opposite substrate is shown in FIG.
As shown in, the plurality of data signal lines 10 are formed in the direction perpendicular to the scanning signal lines 5.

The element-side substrate and the counter substrate are bonded together with the picture element electrodes 8 and the scanning signal lines 5 inside, and a liquid crystal layer is sealed in the gap between them to form a liquid crystal display device.

This liquid crystal display device can be manufactured as follows.

First, on a glass substrate to be a device side substrate,
A Ta thin film is laminated by a sputtering method and patterned by a photolithography method to form a scanning signal line 5. At this time, the resistor portion 12 and the capacitor portion 13 shown in FIG. 13 are also patterned at the same time.

Next, a ZnS thin film is formed by sputtering and patterned by photolithography to form a ZnS thin film 6. A Ti thin film is laminated thereon by a sputtering method and is patterned by a photolithography method to form a Ti thin film 7.
This Ti thin film 7, ZnS thin film 6, and scanning signal line 5
The layer structure becomes the non-linear resistance two-terminal element 9.

Further, an ITO thin film is laminated by a sputtering method and is patterned by a photolithography method to form a pixel electrode 8. By the above, the element side substrate is completed.

Next, on the glass substrate to be the opposite substrate,
An ITO thin film is formed by a sputtering method and is patterned by a photolithography method to form a stripe-shaped data signal line 10. Through the above steps, the opposite substrate is completed.

These two substrates are attached so that the scanning signal lines 5 and the data signal lines 10 are orthogonal to each other and fixed with a sealing resin, and the gap is filled with liquid crystal to form a liquid crystal layer. With the above, the liquid crystal display device is completed.

After that, the scan driver is connected to the scanning signal line terminal which is output to the outside, the data driver is connected to the data signal line terminal which is output to the outside, and the scanning driver is connected to the scanning driver shown in FIG.
The rectangular wave pulse scanning signal 106 shown in FIG. 18 is generated, and the data signal 107 shown in FIG. 18 is generated in the data driver.

In the liquid crystal display device of this embodiment, the capacitance CLC of the liquid crystal layer is 0.8 pF, the required liquid crystal layer applied voltage VLC is 1.0 to 5.0, and the length t of the selection period is 35 × 10 5.
^-6 sec, the electrostatic capacitance Cz of the non-linear resistance 2-terminal element is 0.
2pF, current limit value Izmax of non-linear resistance two-terminal element is 4.8 × 10 ⁻⁷ A, applied voltage Vzmax at that time is 20V
Has become.

Since the scanning signal line 5 has the resistor portion 12 and the capacitor portion 13, the rectangular wave pulse signal output from the scanning driver has a waveform as shown in FIG. 8 (a). Therefore, the waveforms of Vin and VLC in the case where the liquid crystal layer applied voltage is large are as shown in FIG. 9 (a), and the waveforms of Vin and VLC in the case where the liquid crystal layer applied voltage is small are shown in FIG. 9 (b). As shown in.

The scanning signal voltage during the selection period is 21.0 V,
When the data signal voltage was set to ± 3.5 V, good display could be obtained.

In the above description, the voltage varied across the series circuit composed of the liquid crystal layer portion corresponding to one picture element and the non-linear resistance two-terminal element immediately after the start of the selection period and immediately before the end of the selection period. However, the present invention is not limited to this, and can be implemented by applying a voltage having a gradient in the voltage value during a part of the selection period.

In the above embodiment, the MSM (Metal Semiconductor Metal) element in which the ZnS thin film is sandwiched between the Ta thin film and the Ti thin film is used as the non-linear resistance two-terminal element, but the MSM in which the semiconductor other than ZnS is sandwiched between the metal films is used. MIM (Metal Insulator) with elements and insulators sandwiched by metal films
Various non-linear resistance two-terminal elements such as a metal element can be used.

[0065]

As is apparent from the above description, according to the present invention, the voltage V applied across the series circuit composed of the liquid crystal layer portion corresponding to one picture element and the non-linear resistance two-terminal element.
In is changed so as to have a gradient in the selection period, and the change in the voltage applied to the non-linear resistance two-terminal element during the selection period is small. Therefore, compared to the conventional liquid crystal display device using the rectangular wave pulse voltage, the liquid crystal layer applied charges can be increased even if the current limit values of the non-linear resistance two-terminal elements are equal. As a result, a good display can be obtained by sufficiently increasing the voltage applied to the liquid crystal layer without prolonging the selection period or increasing the current limit value Izmax.

When the rectangular wave output from the scanning driver is rounded by using a circuit in which a resistor and a capacitor are combined, it is difficult to obtain an optimum scanning signal waveform, but it has been used conventionally. The existing scan driver can be used as it is, and it is not necessary to use a special scan driver.

[Brief description of drawings]

FIG. 1A is a diagram showing a liquid crystal layer applied voltage VLC, a nonlinear resistance two-terminal element applied voltage Vz, and a voltage Vin applied to both ends of a series circuit according to one embodiment of the method of the present invention, b) is the current I of the non-linear resistance two-terminal element at that time
It is a figure which shows z.

FIG. 2A is a voltage applied to a liquid crystal layer applied voltage VLC, a nonlinear resistance two-terminal element applied voltage Vz, and both ends of a series circuit when the non-linear resistance two-terminal element current in the selection period is substantially constant in the present invention. It is a figure showing voltage Vin,
(B) is a diagram showing a current Iz of the non-linear resistance two-terminal element at that time.

FIG. 3 is a diagram showing an example of a liquid crystal layer applied voltage VLC and a voltage Vin applied to both ends of a series circuit when displaying with a small liquid crystal layer applied voltage in the method of the present invention.

4A shows a scanning signal waveform used in the driving method of FIG. 3, and FIG. 4B shows a data signal waveform at that time.

FIG. 5 is a diagram showing another embodiment of the liquid crystal layer applied voltage VLC and the voltage Vin applied to both ends of the series circuit in the case of performing display with a small liquid crystal layer applied voltage in the method of the present invention.

6A shows a scanning signal waveform used in the driving method of FIG. 5, and FIG. 6B shows a data signal waveform at that time.

FIG. 7 is a circuit diagram for realizing a scanning signal waveform used in the method of the present invention from a rectangular wave pulse.

8A shows a scanning signal waveform when the circuit of FIG. 7 is used, and FIG. 8B shows a data signal waveform at that time.

9A is a case where the signal waveform of FIG. 8 is used, and is a liquid crystal layer applied voltage VLC and a voltage Vin applied to both ends of the series circuit when displaying with a large liquid crystal layer applied voltage.
8B shows the case where the signal waveform of FIG. 8 is used, and the liquid crystal layer applied voltage VLC and the voltage Vin applied to both ends of the series circuit when displaying with a small liquid crystal layer applied voltage are shown.
Indicates.

10 is a cross-sectional view showing an element-side substrate of the liquid crystal display device used in Example 1. FIG.

11 is a plan view showing an element-side substrate of the liquid crystal display device used in Example 1. FIG.

FIG. 12 is a plan view showing a counter-side substrate of the liquid crystal display device used in Example 1.

13 is a plan view showing an element side substrate of a liquid crystal display device used in Example 2. FIG.

FIG. 14A is a diagram showing a liquid crystal layer applied voltage VLC, a nonlinear resistance two-terminal element applied voltage Vz, and a voltage Vin applied to both ends of a series circuit in a conventional method for driving a liquid crystal display device, b) is a diagram showing a current Iz of the non-linear resistance two-terminal element at that time.

FIG. 15 is a plan view showing an element-side substrate of a general liquid crystal display device.

FIG. 16 is a plan view showing a counter substrate of a general liquid crystal display device.

FIG. 17 is a diagram showing an equivalent circuit of a general liquid crystal display device.

FIG. 18 is a diagram showing a scanning signal waveform and a data signal waveform used for driving a conventional liquid crystal display device.

[Explanation of symbols]

 5 Scanning Signal Line 6 ZnS Thin Film 7 Ti Thin Film 8 Pixel Electrode 9 Nonlinear Resistance 2 Terminal Element 10 Data Signal Line 11 Scanning Signal Line Terminal 12 Resistor Section 13 Capacitor Section

Claims (3)

[Claims] 1. A plurality of scanning signal lines and a plurality of data signal lines pass through the periphery of picture element electrodes arranged in a matrix and each scanning signal line intersects with each data signal line. A non-linear resistance two-terminal element provided in the vicinity of a portion where both signal lines intersect is connected to the pixel electrode, the scanning signal line and the data signal line, and the scanning signal line has a selection period. In a liquid crystal display device for applying a scanning signal having a non-selection period, applying a data signal to the data signal line, and applying a voltage to the pixel electrode via the non-linear resistance two-terminal element, A voltage having a gradient in voltage value is applied to both ends of a series circuit composed of a corresponding liquid crystal layer portion and the non-linear resistance two-terminal element, and applied to the non-linear resistance two-terminal element in the selection period. Liquid crystal display device that reduces the voltage change Driving method. 2. The liquid crystal display device according to claim 1, wherein a voltage obtained by transforming a rectangular wave pulse voltage by a circuit including at least a resistor and a capacitor is applied to both ends of the series circuit during the selection period. Driving method. 3. A voltage that changes at a rate substantially equal to the voltage applied to both ends of the liquid crystal layer portion during the selection period is applied to both ends of the series circuit during the selection period, and the voltage is applied to the both ends of the selection period during the selection period. The method of driving a liquid crystal display device according to claim 1, wherein the voltage applied to the non-linear resistance two-terminal element is made substantially constant.