JPH08292420A - Method for driving liquid crystal display device - Google Patents

Abstract

PURPOSE: To provide a method for driving a liquid crystal display device having good image quality by rapidly, efficiently, stably and uniformly preventing the change in the current-voltage characteristics of a nonlinear resistance element and preventing the degradation in contrast, flickering and image burn. CONSTITUTION: Scanning signals have a writing voltage Vs in a writing period Ts, a change preventive voltage Vr in a change preventive period Tr for preventing the change in the current-voltage characteristics of the nonlinear resistance element and a data compensation voltage in a data compensation period Td for preventing the deviation in the data voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving method of a liquid crystal display device having a non-linear resistance element, and more particularly to a stable state of the non-linear resistance element which causes a change in current-voltage characteristics depending on display contents, that is, the amount of current flowing through the non-linear resistance element. West,
Further, the present invention relates to a method for driving a liquid crystal display device, which relates to a technique for preventing a change in display quality due to display contents.

[0002]

2. Description of the Related Art In recent years, liquid crystal display devices using a liquid crystal display panel have been increasing in capacity. In the driving method using the multiplex driving for the liquid crystal display device having the simple matrix structure, the contrast is lowered or the response speed is lowered as the time division is increased, and when there are about 200 scanning lines, a sufficient contrast is obtained. Harder to get.

Therefore, in order to eliminate such a defect, an active matrix liquid crystal display panel in which a switching element is provided in each pixel is adopted.

The systems of the active matrix liquid crystal display panel are roughly classified into a three-terminal system using a thin film transistor and a two-terminal system using a non-linear resistance element. Less than,
A conventional technique will be described using a two-terminal non-linear resistance element.

FIG. 15 is a plan view showing the structure of a liquid crystal display panel using a two-terminal non-linear resistance element. FIG.
FIG. 16 is a cross-sectional view showing a cross section taken along line AA of the plan view of the liquid crystal display panel shown in FIG. 15. Hereinafter, FIG. 15 and FIG.
Description will be made by alternately referring to and.

A first electrode 32 is provided on the first substrate 31, and a nonlinear resistance layer 33 is provided on the surface of the first electrode 32. Further, the second electrode 34 is provided so as to overlap the first electrode 32 via the non-linear resistance layer 33, and the non-linear resistance element 30 is configured. A part of the second electrode 34 also serves as the display electrode 35.

On the second substrate 36, a black matrix 37 is provided in the area shown by the diagonal lines 61 in FIG. 15 in order to eliminate light leakage from the gap between the display electrodes 35.

Further, so as to face the display electrode 35,
A counter electrode 39 is provided on the second substrate 36. The counter electrode 39 is provided via the insulating film 38 so as not to come into contact with the black matrix 37 and cause a short circuit.

The first electrode 32 on the first substrate 31 has a region protruding to form the nonlinear resistance element 30, and the second electrode 34 and the first electrode in the region of the nonlinear resistance element 30. 32 overlaps.
Further, the first electrode 32 and the display electrode 35 have a fixed gap.

The display electrode 35 is arranged so as to overlap the counter electrode 39 through the liquid crystal 41, and becomes a pixel portion of the liquid crystal display panel.

The black matrix 37 is a display electrode 35.
It is configured so as to protrude into the inner region of the display electrode 35, and functions to prevent leakage of light from the periphery of the display electrode 35. And
The liquid crystal display device performs a predetermined display by changing the transmittance of the liquid crystal 41 in the opening area of the black matrix 37 on the display electrode 35.

Further, the first substrate 31 and the second substrate 36 described above are provided with alignment films 40 and 40, respectively, as processing layers in order to regularly arrange the molecules of the liquid crystal 41. Furthermore, a spacer 42 allows the first substrate 31 and the second substrate 36 to face each other with a constant gap, and a liquid crystal 41 is sealed between the first substrate 31 and the second substrate 36. .

An equivalent circuit of the non-linear resistance elements 30 and the liquid crystal 41 provided in the matrix shown in FIGS. 15 and 16 is shown in FIG.
7 shows the circuit diagram. The circuit diagram of FIG. 17 shows an equivalent circuit of a liquid crystal display panel using the nonlinear resistance element 30 shown in FIG.

Scan electrodes S1 to SN and signal electrodes D1 to DN
Are provided on the facing surfaces of the first substrate 31 and the second substrate 36, respectively. The nonlinear resistance element 41 and the liquid crystal pixel 4 are provided at the intersections of the scanning electrodes and the signal electrodes.
And a display pixel composed of two.

When a drive voltage for turning on the liquid crystal pixel 42 is applied, the resistance of the non-linear resistance element 41 is small and the liquid crystal pixel 42 is turned on with a small time constant. On the other hand, when the drive voltage is turned “off”, the resistance of the non-linear resistance element 41 exhibits a large value and discharges with a large time constant.

As a result, the ratio of the effective value of the voltage applied to the liquid crystal at the time of "on" and that at the time of "off" becomes large, and high-density multiplex driving becomes possible.

Drive waveforms used for display of the liquid crystal display device will be described with reference to FIGS. 18 and 19. FIG. 18 shows the waveform of the scanning signal, and FIG. 19 shows the waveform of the data signal.

As shown in FIG. 18, the write voltage Vs is applied during the standard write time (1H = Ts) that is time-divided, and a large voltage is applied to the non-linear resistance element to turn on the non-linear resistance element.

At this time, as the data signal, a signal voltage for displaying the intended display content is applied. In the prior art shown here, the so-called pulse width modulation is used in which the target display content is plus or minus VD1 with the time width TD to which the data signal voltage is applied.

The standard writing period (1H = Ts) is, for example, when the number of scanning lines is 200 and the period of the positive side field or the negative side field is 16 milliseconds (msec).
16 milliseconds / 200 = 80 microseconds (μsec).

In the writing period Ts, in order to prevent the charges accumulated in the liquid crystal capacitance from changing through the non-linear resistance element while the writing period Ts exists in the other scanning electrodes in a time division manner, the standard writing period ( The holding voltage Vh is applied during the holding period Th other than 1H = Ts).

Here, in the actual display, the scan electrodes S1 to S are
There is a field inversion drive method in which N uses a write voltage of the same polarity, or a row-by-row inversion drive method in which display is performed while inverting the polarity of the write voltage in the odd and even rows of the scan electrodes S1 to SN.

[0023]

However, in either of the field inversion driving method and the row-by-row inversion driving method, the bias of the data voltage occurs depending on the display content. When this bias is generated, a biased voltage is applied to the non-linear resistance element during the holding period Th, and a so-called crosstalk phenomenon occurs that is affected by other data signals.

Further, some non-linear resistance elements show a change from the initial current-voltage characteristic due to the current flowing through the non-linear resistance element during driving of the liquid crystal display panel. For example, when white and black fixed display is performed on the liquid crystal display panel, the amount of current flowing through the nonlinear resistance element differs between black display and white display.

Therefore, the current-voltage characteristics of the non-linear resistance element differ between white display and black display, and even if the image is switched after the fixed display for a certain period of time, the fixed image remains as an afterimage on the display. The phenomenon occurs. This afterimage phenomenon will be described with reference to FIG. The liquid crystal display device has a normally white display. The graph of FIG.
It shows the change in transmittance when changing the voltage at minute intervals.

First, the displayed voltage (V1) with a transmittance of 50%
Is applied for 5 minutes (non-selection period: T1), and then transmittance 1
0% display voltage (V2) for 5 minutes (selection period: T2)
Then, the same voltage (V3) as the voltage (V1) applied during the first non-selection period of T1 is applied again for 5 minutes (non-selection period: T3).

The afterimage phenomenon is a phenomenon in which a difference (ΔT) occurs in transmittance even though the voltages applied to the non-selection period T1 and the non-selection period T3 are equal. The transmittance difference ΔT in the above-described liquid crystal display device was 5%.

As is apparent from the above description, the occurrence of the afterimage phenomenon causes display contents different from the image to be originally displayed. For this reason, the afterimage phenomenon significantly deteriorates the quality of the liquid crystal display device, which is a serious problem in practical use as a liquid crystal display device.

As a major cause of the above-mentioned afterimage phenomenon,
There is a display content, for example, a difference in the amount of current flowing through the non-linear resistance element due to the difference between black display and white display, which causes a difference in the change in the current-voltage characteristic of the non-linear resistance element.

The change in the current-voltage characteristic will be described with reference to FIG. FIG. 21 is a graph showing the current-voltage characteristics of the nonlinear resistance element. As shown in FIG. 21, the horizontal axis represents the voltage applied to the nonlinear resistance element, and the vertical axis represents the current flowing in the nonlinear resistance element on the logarithmic axis. The solid line B is a curve showing the current-voltage characteristic after white display for a certain period of time, and the broken line C is a curve showing the characteristic after black display for a certain period of time.

The characteristics after white display and black display are shown in FIG.
As shown in FIG. 1, a difference occurs between the solid line B and the broken line C, and the solid line B
And the difference between the broken line C causes the afterimage phenomenon described above. Due to the occurrence of the image sticking, the display quality of the liquid crystal display device is deteriorated.

Further, the liquid crystal layer used in the liquid crystal display device has a so-called liquid crystal dielectric anisotropy in which the molecular orientation is deformed by a voltage and the capacity of the liquid crystal is changed depending on the display content.
Therefore, the capacitance ratio between the liquid crystal and the non-linear resistance element changes depending on the displayed contents, and the change in the current-voltage characteristic of the non-linear resistance element is further emphasized.

An object of the present invention is to provide a driving method of a liquid crystal display device capable of suppressing the change of the voltage-current characteristics due to the display contents of the above-mentioned nonlinear resistance element and maintaining the initial characteristics.

A further object of the present invention is to prevent the occurrence of data voltage bias due to display contents, to prevent crosstalk, and to prevent changes in current-voltage characteristics due to data voltage bias, thereby reducing contrast and flickering. It is an object of the present invention to provide a method of driving a liquid crystal display device having good image quality by preventing the phenomenon and image sticking phenomenon.

Further, an object of the present invention is to apply a voltage for canceling out the dielectric anisotropy of liquid crystal depending on the display content, to make the current-voltage characteristic of the non-linear resistance element depending on the display content very small, and to prevent image burn-in. It is an object of the present invention to provide a method for driving a liquid crystal display device for preventing the above.

A further object of the present invention is to prevent different steep currents from flowing at the initial stage of the writing period Ts depending on the display content of the element, and to reduce long-term changes in the current-voltage characteristic of the element. A method of driving a liquid crystal display device is provided.

[0037]

In order to achieve the above object, the following driving method is adopted in the driving method of the liquid crystal display device of the present invention.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage Vh is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. It is characterized by having Vd.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through a non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element, a scanning signal is a writing period. A change prevention period T having a write voltage Vs at Ts and preventing a change in the current-voltage characteristic of the nonlinear resistance element
The data compensating voltage Vd is included in the data voltage compensating period Td for preventing the bias of the data voltage by having the change prevention voltage Vr in r
The change prevention voltage Vr is larger than the write voltage Vs, and the data compensation voltage Vd has the same polarity as the write voltage Vs.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
The data signal VD1 according to the display content is applied to s, the constant data voltage VD0 is applied to the scan signal change prevention period Tr regardless of the display content, and the data signal of the writing period Ts is applied to the scan signal data voltage compensation period Td. It is characterized in that an inverted signal of VD1 is applied.

In the driving method of the liquid crystal display device of the present invention, the write voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the write period Ts via the scanning signal and the data signal, and is held in the hold period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
The data signal VDs according to the display content is applied to s, and the maximum amplitude V of the data voltage is applied to the scan signal change prevention period Tr.
It is characterized in that D1 is applied and an inverted signal of the data signal VDs of the writing period Ts is applied during the data voltage compensation period Td of the scanning signal.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
s, the change prevention period Tr, and the data voltage compensation period Td have different data voltage amplitudes.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
A data signal VD1 according to the display content is applied to s, a large voltage VB0 is applied to the scan signal change prevention period Tr when the liquid crystal capacity is small due to the display content, and a small voltage VB1 is applied to the scan signal change prevention period Tr to apply the scan signal. Of the constant data voltage VB3 during the data voltage compensation period Td of
Is applied.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
A data signal VD1 according to the display content is applied to s, a large voltage VB0 is applied to the scan signal change prevention period Tr when the liquid crystal capacity is small due to the display content, and a small voltage VB1 is applied to the scan signal change prevention period Tr to apply the scan signal. In the data voltage compensation period Td, the inverted signal of the data signal VD1 in the writing period Ts is applied.

According to the driving method of the liquid crystal display device of the present invention, the write voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the write period Ts via the scanning signal and the data signal, and is held in the hold period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
The data signal VDs according to the display content is applied to s, the intermediate amplitude VD2 of the data voltage is applied to the scan signal change prevention period Tr, and the data signal VDs of the writing period Ts is inverted during the data voltage compensation period Td of the scan signal. A signal is applied, and the scanning signal has a change prevention voltage Vr in a plurality of change prevention periods Tr for preventing a change in the current-voltage characteristic of the non-linear resistance element.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal, and is held in the holding period Th. A driving method of a liquid crystal display device having a non-linear resistance element in which a voltage is applied to a liquid crystal through the non-linear resistance element and a current-voltage characteristic of the non-linear resistance element changes according to a current flowing through the non-linear resistance element is used. The write voltage Vs is included in the period Ts, the change prevention voltage Vr is included in the change prevention period Tr that prevents the current-voltage characteristics of the nonlinear resistance element from changing, and the data compensation voltage is included in the data voltage compensation period Td that prevents the bias of the data voltage. Vd, and the data signal is a scanning signal writing period T
A data signal VD1 according to the display content is applied to s, a large voltage VB0 is applied to the scan signal change prevention period Tr when the liquid crystal capacity is small due to the display content, and a small voltage VB1 is applied to the scan signal change prevention period Tr to apply the scan signal. Of the constant data voltage VB3 during the data voltage compensation period Td of
Further, the scanning signal has a data voltage compensation voltage Vd in a plurality of data voltage compensation periods Td.

According to the driving method of the liquid crystal display device of the present invention, the writing voltage Vs is applied to the non-linear resistance elements arranged in a matrix in the writing period Ts via the scanning signal and the data signal and is held in the holding period Th. The voltage Vh is applied to the liquid crystal through the non-linear resistance element, and the current-voltage characteristic of the non-linear resistance element changes according to the current flowing through the non-linear resistance element. The write voltage Vs is included in the write period Ts, the change prevention voltage Vr is included in the change prevention period Tr for preventing the change of the current-voltage characteristics of the non-linear resistance element, and the data compensation is performed in the data voltage compensation period Td for preventing the bias of the data voltage. The change prevention period Tr having the voltage Vd and preventing the change of the current-voltage characteristic of the non-linear resistance element includes a write period Ts and a data voltage compensation period. Characterized in that than a r a short period of time.

In the driving method of the liquid crystal display device of the present invention, the voltage VS1 smaller than the write voltage Vs is applied at the beginning of the write period Ts of the scanning signal, and the write voltage changes from VS1 to Vs within the write period Ts. It is characterized by doing.

By adopting the driving method of the liquid crystal display device of the present invention, the writing period Ts used for actual display is obtained.
In addition, a change prevention period Tr for preventing a difference in change in current-voltage characteristics is provided.

As a result, the actual writing period Ts
The difference between the current-voltage characteristics of the non-linear resistance element that occurs in the
It is possible to eliminate the difference in current-voltage characteristics. Therefore, it is possible to eliminate the difference between the current-voltage characteristics of the non-linear resistance element depending on the display content.

Further, during the change prevention period Tr, the difference between the changes in the current-voltage characteristics of the non-linear resistance element due to the above-mentioned display contents is set to the intermediate voltage VD of a constant data voltage which does not depend on the display contents.
0 is applied. As a result, the difference in the current-voltage characteristics of the non-linear resistance element can be well controlled without depending on the display content.

Further, if it is not enough to apply a constant voltage during the change prevention period Tr depending on the display content due to the dielectric constant anisotropy of the liquid crystal depending on the display content, the dielectric constant of the liquid crystal is anisotropic during the change prevention period Tr. A voltage that corrects the property, that is, a large voltage is applied when the liquid crystal capacity is small, and a small voltage is applied when the liquid crystal capacity is large. The change in current-voltage characteristics of the resistance element can be reduced.

Further, in the case of correcting the dielectric anisotropy of the liquid crystal, a constant voltage VB3 can be applied during the data voltage compensation period Td to prevent the rounding of the initial waveform during the writing period Ts. , Crosstalk can be reduced.

Therefore, according to the driving method of the liquid crystal display device of the present invention, the current-depending on the display content of the nonlinear resistance element
It is possible to prevent a difference in voltage characteristics and, at the same time, prevent a crosstalk phenomenon that occurs when a bias of the data voltage depending on the display content occurs. Alternatively, it is possible to reduce the difference in current flowing through the non-linear resistance element due to the dielectric anisotropy of the liquid crystal.

Furthermore, the change prevention period Tr for preventing the difference between the current-voltage characteristics is shortened, and the change prevention period Tr is applied a plurality of times. As a result, it is possible to efficiently reduce the difference between the current-voltage characteristics of the non-linear resistance element depending on the display content without causing deterioration of display quality.

Further, the voltage applied at the beginning of the writing period Ts is made smaller than the voltage applied at the latter half of the writing period Ts. Further, by increasing the voltage stepwise or gradually from the initial voltage of the writing period Ts, it is possible to reduce the current flowing through the non-linear resistance element in the initial period of the writing period Ts. Therefore, the current flowing through the nonlinear resistance element can be rapidly controlled at the beginning of the writing period Ts,
It is possible to reduce current deterioration of the non-linear resistance element.

Furthermore, by shortening the change prevention period Tr and the data voltage compensation period Td, it is possible to reduce the difference between the current-voltage characteristics of the non-linear resistance element depending on the display content without lowering the display quality.

[0058]

BEST MODE FOR CARRYING OUT THE INVENTION A method for driving a liquid crystal display device in the best mode for carrying out the present invention will be described below with reference to the drawings. The liquid crystal display panel used in the embodiment of the present invention has the same structure as the structure described with reference to FIGS. 15, 16, and 17.

First, drive waveforms used in the method of driving the liquid crystal display device according to the first embodiment of the present invention will be described with reference to the waveform diagrams of FIGS. 1 and 2. The waveform diagram of FIG. 1 is a waveform diagram showing a scanning signal waveform used in the first embodiment of the present invention. FIG. 2 is a waveform diagram showing a data signal waveform used in the first embodiment of the present invention. Hereinafter, the driving method according to the first embodiment of the present invention will be described by alternately using FIG. 1 and FIG.

The scanning signal waveform shown in FIG. 1 is a waveform applied to the scanning electrode SN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. The data signal waveform shown in FIG. 2 is a waveform applied to the data electrode DN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. 1 and 2, the vertical axis represents voltage and the horizontal axis represents time.

As shown in the waveform diagram of FIG. 1, the scanning signal waveform is time-divided, and during the standard writing period (1H), the change prevention period Tr for preventing the change of the current-voltage characteristic of the non-linear resistance element. And the data voltage compensation period Td,
It has a writing period Ts.

Then, the change prevention voltage Vr is applied during the change prevention period Tr for preventing the change of the current-voltage characteristic of the nonlinear resistance element of the scanning signal waveform. The write voltage Vs is applied during the write period TS. The data compensation voltage Vd is applied during the data voltage compensation period Td.

In the embodiment of the present invention, the change prevention voltage Vr
Applies a voltage having an absolute value larger than the write voltage Vs and the data compensation voltage Vd. Further, the write voltage Vs and the data compensation voltage Vd have opposite polarities and have the same absolute value.

Further, as shown in FIG. 2, the data signal waveform has a period corresponding to the scanning signal writing period Ts.
As the voltages of the data voltage + VD1 and the data voltage −VD1, a constant voltage is applied irrespective of the display content, and depending on the display content, the data voltage + VD1 and the data voltage −VD1.
A driving method is adopted in which the period for applying voltage is made variable to perform the desired display.

For example, in the negative side field writing period Ts, the data voltage + VD1 is applied for the period T1, and the data voltage −VD1 is applied for the period T2. A driving method that changes the ratio between the period T1 and the period T2 is adopted. This driving method is called a pulse width modulation driving method.

Next, in the period corresponding to the data voltage compensation period Td, the data voltage having the opposite polarity to the writing period Ts is applied by using the pulse width modulation driving method.
That is, in the data voltage compensation period Td, the data voltage −VD1 is applied for the period T3, and the data voltage + V
D1 is applied for the period T4.

The period T3, the period T1, the period T4, and the period T2 have the same time. In terms of time, the order of the period T3 is followed by the period T4, the period T4 is followed by the period T1, and the period T1 is followed by the period T2.

Further, in the change prevention period Tr for preventing the change of the current-voltage characteristic of the non-linear resistance element, the data signal waveform shows the data voltage + VD1 and the data voltage -VD.
The voltage VD0, which is the central voltage of 1, is applied, and a voltage that does not depend on the display content is provided.

The scan signal waveform has a standard writing period (1
The holding voltage Vh is applied during the holding period Th other than H).

The afterimage phenomenon when the driving method according to the first embodiment of the present invention is used will be described with reference to FIGS. 3 and 4. FIG. 3 is a graph showing the afterimage phenomenon, and FIG. 4 is a graph showing changes in the current-voltage characteristics of the nonlinear resistance element. In the graph showing the afterimage phenomenon shown in FIG. 3, the liquid crystal display device uses normally white display as in FIG. 14 described in the related art. The graph of FIG.
It shows the change in transmittance when changing the voltage at minute intervals.

First, the displayed voltage (V1) with a transmittance of 50%
Is applied for 5 minutes (non-selection period: T1), and then transmittance 1
0% display voltage (V2) for 5 minutes (selection period: T2)
Then, the same voltage (V3) as the voltage (V1) applied during the first non-selection period of T1 is applied again for 5 minutes (non-selection period: T3).

The afterimage phenomenon is caused by the non-selection period T1 and the non-selection period T.
This is a phenomenon in which a difference (ΔT) occurs in the transmittance even though the voltages applied to 3 and 3 are equal. By using the driving method shown in the first embodiment of the present invention, the difference in transmittance (Δ
T) becomes extremely small. At this time, the transmittance difference ΔT in the liquid crystal display device was 0.1%, which was improved to the extent that it cannot be detected by the naked eye.

Next, changes in the current-voltage characteristics of the non-linear resistance element depending on the displayed contents when the driving method according to the first embodiment of the present invention is used will be described with reference to FIG. FIG. 4 is a graph showing the current-voltage characteristics of the non-linear resistance element.
The horizontal axis of the graph in FIG. 4 represents the voltage applied to the nonlinear resistance element, and the vertical axis represents the current flowing in the nonlinear resistance element on the logarithmic axis. The solid line X is a curve showing the current-voltage characteristic after white display for a certain period of time, and the broken line Y is a curve showing the characteristic after black display for a certain period of time.

As for the characteristic difference between the white display and the black display, as shown in the graph of FIG. 4, there is almost no difference (ΔI) between the solid line X and the broken line Y. The cause of this is that in the driving method of the present invention, the change prevention voltage Vr that does not depend on the display content.
This is because the current-voltage characteristics of the non-linear resistance element change on average irrespective of the display content by applying. Therefore, there is no difference in the change in the current-voltage characteristics of the non-linear resistance element due to the displayed contents.

Further, during the data voltage compensation period Td,
In the writing period Ts, a voltage that is symmetrical with respect to the central voltage VD0 and that has the same time for applying the symmetrical voltage is applied. Therefore, the deviation of the data voltage does not occur depending on the displayed contents.

Therefore, the non-linear resistance element is turned on during the writing period Ts, and the electric charges written in the liquid crystal are generated during the holding period Th via the non-linear resistance element generated by the bias of the data voltage + VD1 and the data voltage −VD1 depending on the display content. It does not change the charge of the liquid crystal.

Therefore, the charge accumulated in the liquid crystal is not changed by the data voltage during the holding period Th.
There is no change in charge depending on the displayed contents. For this reason,
The so-called crosstalk, which is a change in the image connected to the scanning electrodes or the data signal electrodes, is eliminated.

Next, a method of driving the liquid crystal display device according to the second embodiment of the present invention will be described. Driving waveforms used in the driving method of the liquid crystal display device according to the second embodiment of the present invention will be described with reference to the waveform diagrams of FIGS. 5 and 6. FIG. 5 is a waveform diagram showing a scanning signal waveform used in the second embodiment of the present invention. FIG. 6 is a waveform diagram showing a data signal waveform used in the second embodiment of the present invention. Hereinafter, the second embodiment of the present invention will be described by alternately using FIG. 5 and FIG.

The scanning signal waveform shown in FIG. 5 is a waveform applied to the scanning electrode SN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. The data signal waveform shown in FIG. 6 is a waveform applied to the data electrode DN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. Here, the vertical axis in each of FIGS. 5 and 6 represents voltage, and the horizontal axis represents time.

As shown in FIG. 5, the scanning signal waveform is time-divided, and the standard writing period (1H (SN))).
During the period, a change prevention period Tr3 for preventing a change in the current-voltage characteristic of the nonlinear resistance element, a change prevention period Tr7, a data voltage compensation period Td, and a writing period Ts are included.

Further, in the second embodiment of the present invention, in the scan signal waveform applied to the scan signal electrode SN, the change of the current-voltage characteristic of the non-linear resistance element is shown before the writing period Ts of the scan signal electrode SN. To prevent this, the change prevention period Tr is applied a plurality of times.

The change prevention period Tr for preventing the current-voltage characteristics of the non-linear resistance element from changing a plurality of times is as described below.

Scan signal electrode SN before scan signal electrode SN
-1, scan signal electrode SN-2, and scan signal electrode SN-3 within the standard writing period (1H)
1. The change prevention period Tr2 and the change prevention period Tr6 for preventing the change of the current-voltage characteristic of the non-linear resistance element of No. 1 and the change prevention period Tr1 for preventing the change of the current-voltage characteristic of the non-linear resistance element of scan signal electrode SN-2. And change prevention period Tr5
And a change prevention voltage Vr for preventing a change in the current-voltage characteristics of the non-linear resistance element in a period corresponding to a change prevention period Tr4 for preventing the change in the current-voltage characteristics of the non-linear resistance element of the scan signal electrode SN-3. Apply.

As in the first embodiment, the write voltage Vs is applied during the write period Ts, and the data compensation voltage Td is applied during the data voltage compensation period Td.

In the second embodiment of the present invention, the change prevention voltage Vr is a voltage having an absolute value larger than the write voltage Vs and the data compensation voltage Vd. Further, the write voltage Vs and the data compensation voltage Vd have opposite polarities and have the same absolute value.

Further, as shown in FIG. 6, the data signal waveform shows that the data voltage + VD1 and the data voltage −VD1 are in the period corresponding to the scanning signal writing period Ts.
A driving method is adopted in which a constant voltage is applied regardless of the display content, and the period for applying the data voltage + VD1 and the data voltage −VD1 is made variable depending on the display content to perform the target display.

For example, in the negative-side field writing period Ts, the data voltage + VD1 is applied for the period T1 and the data voltage −VD1 is applied for the period T2.
A driving method in which the ratio between the period T1 and the period T2 is changed is adopted. This driving method is called a pulse width modulation driving method.

Next, the scanning signal data voltage compensation period T
In the period corresponding to d, the data voltage having the opposite polarity to the writing period Ts is applied by using the pulse width modulation driving method.

Further, the change prevention periods Tr1 to Tr1 for preventing changes in the current-voltage characteristics of the non-linear resistance element applied a plurality of times.
Data voltage + VD1 and data voltage −V are applied to Tr7.
A center voltage VD0 voltage with respect to D1 is applied to provide a voltage that does not depend on the display content.

The scanning signal waveform has a standard writing period (1
The holding voltage Vh is applied during the holding period Th other than H).

Regarding the evaluation of the afterimage phenomenon when the driving method shown in the second embodiment of the present invention is used, as in the first embodiment, first, the display voltage (V1) with the transmittance of 50% is displayed.
Is applied for 5 minutes (non-selection period: T1), and then transmittance 1
0% display voltage (V2) for 5 minutes (selection period: T2)
Then, the same voltage (V3) as the voltage (V1) applied during the first non-selection period of T1 is applied again for 5 minutes (non-selection period: T3).

The afterimage phenomenon is caused by the non-selection period T1 and the non-selection period T.
This is a phenomenon in which a difference (ΔT) occurs in the transmittance even though the voltages applied to 3 and 3 are equal. By using the driving method shown in the second embodiment of the present invention, the difference in transmittance (Δ
T) becomes extremely small. At this time, the transmittance difference ΔT in the liquid crystal display device is 0.05%, which can be improved to the extent that it cannot be detected by the naked eye at all.

When the second embodiment of the present invention is used, the change in the current-voltage characteristics of the non-linear resistance element due to the displayed contents is as follows.
It is extremely small as in the first embodiment.

Further, during the data voltage compensation period Td,
By making the voltage symmetrical with respect to the central voltage VD0 and by making the time for applying each voltage equal, it is possible to prevent the deviation of the data voltage due to the display content. Therefore, during the writing period Ts, the non-linear resistance element is turned “on” to charge the liquid crystal in the holding period T.
Due to the bias of the data voltage + VD1 and the data voltage −VD1 at h, the charge of the liquid crystal is not changed via the nonlinear resistance element.

Therefore, since the charges accumulated in the liquid crystal are not changed by the data voltage during the holding period Th,
There is no change in charge depending on the displayed contents. Therefore, the occurrence of crosstalk, which is a change in the image connected to the scanning electrodes or the data signal electrodes, is eliminated.

Further, in the second embodiment of the present invention, before the writing period Tr, the current of the nonlinear resistance element--
A plurality of change prevention periods Tr for preventing a change in voltage characteristics
Is provided. Therefore, the change prevention period Tr for preventing the change of the current-voltage characteristic of the non-linear resistance element can be set to a low voltage in a short time.

Therefore, the writing period Ts used for actual display can be lengthened, so that the contrast ratio is improved and the display quality can be improved.

Further, the change prevention voltage Vr for preventing the change of the current-voltage characteristic of the non-linear resistance element can be lowered. Therefore, for example, the voltage level of the scanning signal is maintained at the change prevention voltage + Vr (= + Vs) by making the change prevention voltage Vr and the write voltage Vs that prevent the change of the current-voltage characteristic of the non-linear resistance element equal. Voltage +
There are four levels of Vh, change prevention voltage −Vr (= −Vs), and holding voltage −Vh.

Next, a driving method of the liquid crystal display device according to the third embodiment of the present invention will be described. Driving waveforms used in the driving method of the liquid crystal display device according to the third embodiment of the present invention will be described with reference to the waveform diagrams of FIGS. 7 and 8. The waveform diagram of FIG. 7 is a waveform diagram showing a scanning signal waveform used in the third embodiment of the present invention. FIG. 8 is a waveform diagram showing a data signal waveform used in the third embodiment of the present invention. Below, FIG.
And FIG. 8 are used alternately to describe a third embodiment of the present invention.

The scanning signal waveform shown in FIG. 7 is a scanning signal waveform applied to the scanning electrode SN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. Further, the data signal waveform shown in FIG. 8 is a waveform applied to the data electrode DN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. Here, the vertical axis in FIGS. 7 and 8 represents voltage, and the horizontal axis represents time.

As shown in FIG. 7, the scanning signal waveform is time-divided, and during the standard writing period (1H),
It has a change prevention period Tr for preventing a change in the current-voltage characteristic of the nonlinear resistance element, a data voltage compensation period Td, and a writing period Ts.

Further, the change prevention period Tr for preventing the change of the current-voltage characteristic of the nonlinear resistance element is the write period T.
It is shorter than s or the data voltage compensation period Td.

Further, as shown in FIG. 8, the data voltage is
The maximum data voltage + VD1 or data voltage -VD1 is always applied.

Therefore, it is possible to efficiently apply a large voltage to the non-linear resistance element even during a short period of time for preventing the change of the current-voltage characteristic of the non-linear resistance element, and to increase the writing period Ts. Therefore, the display quality of the liquid crystal display device can be improved.

Further, during the change prevention period Tr for preventing the change of the current-voltage characteristic of the nonlinear resistance element, the change prevention voltage V
Apply r. In the writing period Ts, the writing voltage V
s is applied. The data compensation voltage Td is applied during the data voltage compensation period Td.

In the third embodiment of the present invention, the change prevention voltage Vr is a voltage having an absolute value larger than the write voltage Vs and the data compensation voltage Vd. further,
The write voltage Vs and the data compensation voltage Vd have opposite polarities and have the same absolute value. Further, the same voltage is applied as the change prevention voltage Vr and the write voltage Vs for preventing the change of the current-voltage characteristic of the nonlinear resistance element.

Further, as for the data signal waveform, a voltage between the data voltage + VD1 and the data voltage −VD1 is applied according to the display content in the period corresponding to the writing period Ts. This driving method is called a pulse height modulation driving method.

Next, in the period corresponding to the data voltage compensation period Td, the data voltage having the reverse polarity of the scanning signal writing period Ts is applied by using the pulse height modulation driving method.

That is, when the data voltage + VD1 is applied during the writing period Ts, the data voltage -VD1 is applied during the data voltage compensation period Td. When the voltage of 1/3 of the data voltage + VD1 is applied during the writing period Ts, the voltage of 1/3 of the data voltage + VD1 is applied during the data voltage compensation period Td.

Further, during the change prevention period Tr for preventing the change in the current-voltage characteristic of the non-linear resistance element, for example, the change prevention voltage for preventing the change in the current-voltage characteristic of the non-linear resistance element is + Vr in the data signal waveform. In the case of, the data voltage is set to -VD1, and when the change prevention voltage is -Vr, the data voltage is applied to + VD1.

The scanning signal waveform has a standard writing period (1
The holding voltage Vh is applied during the holding period Th other than H).

Regarding the afterimage phenomenon when the driving method shown in the third embodiment of the present invention is used, as in the first embodiment, first, the display voltage (V1) with the transmittance of 50% is set to 5%. Applied for 1 minute (non-selection period: T1), then the transmittance is 1
0% display voltage (V2) for 5 minutes (selection period: T2)
Then, the same voltage (V3) as the voltage (V1) applied during the first non-selection period of T1 is applied again for 5 minutes (non-selection period: T3).

The afterimage phenomenon is a phenomenon in which a difference (ΔT) occurs in the transmittance even though the voltages applied to the non-selection period T1 and the non-selection period T3 are equal. By using the driving method according to the third embodiment of the present invention, the difference in transmittance (ΔT) becomes extremely small. At this time, the transmittance difference ΔT in the liquid crystal display device was 0.1%, which was improved to the extent that it cannot be detected by the naked eye.

When the third embodiment of the present invention is used, the change in the current-voltage characteristics of the nonlinear resistance element due to the displayed contents is as follows.
It is extremely small as in the first embodiment.

Further, during the data voltage compensation period Td,
Since the voltage is always symmetrical with respect to the VD0 voltage which is the center voltage, and the time when each voltage is applied is also symmetrical, the bias of the data voltage due to the display content does not occur, so that the non-linear resistance during the writing period Ts is eliminated. The element is turned "on" and the charge written in the liquid crystal is held for a holding period Th.
In addition, the bias of the data voltage + VD1 and the data voltage −VD1 prevents the charge of the liquid crystal from changing via the non-linear resistance element.

Therefore, the charges accumulated in the liquid crystal are not changed by the data voltage during the holding period Th. Therefore, the change in charge depending on the display content is eliminated, and the occurrence of crosstalk, which is a change in the image connected to the scan electrodes or the data signal electrodes, is eliminated.

Next, a driving method of the liquid crystal display device according to the fourth embodiment of the present invention will be described. Driving waveforms used in the driving method of the liquid crystal display device according to the fourth embodiment of the present invention will be described with reference to the waveform diagrams of FIGS. 9 and 10. The relationship between the drive voltage of the liquid crystal and the dielectric constant will be described with reference to FIG. An equivalent circuit diagram showing the relationship between the nonlinear resistance element and the liquid crystal of the active matrix type liquid crystal display device will be described with reference to FIG.

First, FIG. 11 shows the characteristics of liquid crystal drive voltage and liquid crystal dielectric anisotropy. The drive voltage shown here is a voltage (effective value voltage: Vrms) applied directly to the liquid crystal without passing through the non-linear resistance element. The vertical axis of FIG. 11 is the transmittance (T)
Is the dielectric constant (ε), and the horizontal axis is the effective voltage (Vrms)
Indicates. The liquid crystal is ZLI-4792, which is a general liquid crystal for active matrix liquid crystal display devices, and the polarizing plates are arranged in crossed Nicols, and the case of normally white mode is shown.

As shown in the characteristic diagram of FIG. 11, a curve 11 shows the relationship between the driving voltage (Vrms) to the liquid crystal and the transmittance (T). A curve 12 shows the relationship between the driving voltage (Vrms) and the dielectric constant (ε). It can be seen that the dielectric constant of the liquid crystal changes depending on the voltage applied to the liquid crystal.

FIG. 12 is an equivalent circuit diagram briefly showing an equivalent circuit of the liquid crystal and the nonlinear resistance element in the liquid crystal display device having the nonlinear resistance element. As shown in FIG. 12, the nonlinear resistance element can be represented by a variable resistance 13 and an element capacitance 14. The liquid crystal can be represented by a resistor 15 and a liquid crystal capacitor 16.

Since the liquid crystal capacitance 16 changes with the drive voltage, the ratio of the element capacitance 14 and the liquid crystal capacitance 16 changes with the drive voltage. Further, the ratio of the element capacitances (capacity ratio = element capacitance 14 / liquid crystal capacitance 16) is large when the driving voltage is small, and is small when the driving voltage is large.

Therefore, in the fourth embodiment of the present invention, the data signal waveform applied to the scan signal waveform change prevention period Tr or the data voltage compensation period Td is
A voltage for compensating the dielectric anisotropy of the liquid crystal is applied.

The waveform chart of FIG. 9 is a waveform chart showing the scanning signal waveform used in the fourth embodiment of the present invention. Figure 10
It is a wave form diagram which shows the data signal waveform used for the 4th Embodiment of this invention. Hereinafter, the fourth embodiment of the present invention will be described by alternately using FIG. 9 and FIG. The scanning signal waveform shown in FIG. 9 is a scanning signal waveform applied to the scanning electrode SN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. further,
The data signal waveform shown in FIG. 10 is a waveform applied to the data electrode DN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. Here, the vertical axis in FIGS. 9 and 10 represents the voltage,
The horizontal axis represents time.

As shown in FIG. 9, the scanning signal waveform is time-divided, and during the standard writing period (1H),
It has a change prevention period Tr for preventing a change in the current-voltage characteristic of the nonlinear resistance element, a data voltage compensation period Td, and a writing period Ts.

Further, the change prevention period Tr for preventing the change of the current-voltage characteristic of the non-linear resistance element and the data voltage compensation period Td are shorter than the writing period Ts.

FIG. 10 shows a data signal waveform, and the waveform corresponding to each display content (white, gray, and black display) applied to the positive side field in the standard writing period (1H) is continuously shown. . For a plurality of displays from white to black, the voltage applied during the change prevention period Tr is VB1,
Three types of VB2 and VB3 are classified and applied.

Further, as shown in FIG. 10, the data voltage has three types of data voltage amplitudes. First, in the change prevention period Tr, ± VB0 is used in the case of white display with a small dielectric constant according to the magnitude of the dielectric constant of the liquid crystal. ± VB2 is used in the case of halftone (gray) display in which the dielectric constant is intermediate. In the case of black display with a large dielectric constant, ± VB1 is used.

As described above, since the dielectric constant anisotropy of the liquid crystal can be corrected within the standard writing period (1H), the display content can be easily recognized, and the dielectric constant anisotropy of the liquid crystal depends on the display content. I can compensate.

Further, as shown in FIG. 10, a constant voltage VB3 is applied during the data voltage compensation period Td. This prevents crosstalk depending on the display content.
Further, as shown in FIG. 10, the data voltage compensation period Td
Is ± Vb3. In the writing period Ts, so-called pulse width modulation is used in which the display content is changed by changing the ratio of the period in which ± VB3 (= ± VB1) is applied.

In the white display, during the writing period Ts,
+ VB3 is applied during the period T21 which is the same as the writing period Ts. In gray display, + VB is applied during the writing period Ts.
3 is applied during the period T22 of the writing period Ts, and −VB
3 is applied for the period of T23. During black display, −VB3 is set to the same T as the writing period Ts during the writing period Ts.
It is applied for 24 periods.

Therefore, it is possible to efficiently prevent the change of the current-voltage characteristic of the non-linear resistance element depending on the change of the dielectric constant of the liquid crystal by utilizing the change prevention period Tr.

Further, during the change prevention period Tr for preventing the change of the current-voltage characteristic of the non-linear resistance element, the change prevention voltage V
Apply r. In the writing period Ts, the writing voltage V
s is applied. The data compensation voltage Td is applied during the data voltage compensation period Td.

In the fourth embodiment of the present invention, the change prevention voltage Vr, the write voltage Vs, and the data compensation voltage Vd have the same absolute value. As a result, the scanning signal waveform can be simplified.

The change prevention voltage Vr and the write voltage V
A voltage having the same polarity as that of s is applied, and a voltage having the opposite polarity is applied as the data voltage compensation voltage Vd. The scanning signal waveform includes
The holding voltage Vh is applied during the holding period Th other than the standard writing period (1H).

Regarding the afterimage phenomenon when the driving method shown in the fourth embodiment of the present invention is used, each display is performed for a longer time than in the first embodiment. First of all, the transmittance is 50%
Voltage (V1) displayed for 10 minutes (non-selection period: T1)
Then, apply the applied voltage (V2) with a transmittance of 10% to 1
The voltage is applied for 80 minutes (selection period: T2), and again, the same voltage (V3) as the voltage (V1) applied during the first non-selection period of T1 is applied for 10 minutes (non-selection period: T3).

The afterimage phenomenon is a phenomenon in which a difference (ΔT) occurs in the transmittance even though the voltages applied to the non-selection period T1 and the non-selection period T3 are equal. By using the driving method according to the fourth embodiment of the present invention, the difference (ΔT) in transmittance can be extremely reduced particularly when a constant display is performed for a long time. At this time, the transmittance difference ΔT in the liquid crystal display device was 0.1%, which was improved to the extent that it cannot be detected by the naked eye.

When the fourth embodiment of the present invention is used, the change in the current-voltage characteristics of the non-linear resistance element due to the displayed contents at the initial stage and after the display of the transmittance of 10% for 180 minutes is as follows. It is extremely small as in the embodiment.

Further, during the data voltage compensation period Td,
Be sure to apply a constant voltage VB3 that does not depend on the displayed contents,
At the beginning of the writing period Ts, the delay of the scanning signal waveform or the data signal waveform depending on the display content can be made constant. Therefore, it is possible to reduce the change in the image depending on the display content, so-called crosstalk.

Next, a method of driving the liquid crystal display device according to the fifth embodiment of the present invention will be described. Driving waveforms used in the driving method of the liquid crystal display device according to the fifth embodiment of the present invention will be described with reference to the waveform diagrams of FIGS. 9 and 10.

The fifth embodiment has an initial writing period (T31) and a final writing period (T32) of the scanning signal waveform writing period Ts. Initial write voltage (± Vs) applied during the initial write period (T32)
i) has a two-step write voltage whose absolute value is smaller than the last write voltage (± Vs).

Further, the data signal waveform has a period corresponding to the change prevention period Tr, the data voltage compensation period Td, the initial writing period (T31) and the last writing period (T32). Particularly, a constant voltage (VB0) is applied during the initial writing period (T32).

Next, in the last writing period (T32), a voltage depending on the display content is applied. In the last writing period (T32), the so-called pulse height modulation method is used in which the same voltage is applied and the display content is changed according to the amplitude.

Further, in order to compensate the dielectric anisotropy of the liquid crystal, a method of compensating the dielectric anisotropy of the liquid crystal is adopted during the change prevention period Tr by changing the voltage according to the display content.

The scanning signal waveform shown in FIG. 13 is a scanning signal waveform applied to the scanning electrode SN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. Further, the data signal waveform shown in FIG. 14 is a waveform applied to the data electrode DN of the equivalent circuit diagram of the liquid crystal display panel shown in FIG. Figure 1
3 and FIG. 14, the vertical axis represents voltage and the horizontal axis represents time.

As shown in FIG. 13, the scanning signal waveform is time-divided, and during the standard writing period (1H),
It has a change prevention period Tr for preventing a change in the current-voltage characteristic of the nonlinear resistance element, a data voltage compensation period Td, and a writing period Ts.

Further, the writing period Ts includes an initial writing period (T31) and a final writing period (T32). The initial write voltage (± Vsi) applied in the initial write period (T31) is the last write period (T32).
It is a voltage smaller than the last write voltage (± Vs) applied to the. In the fifth embodiment of the present invention, the writing period Ts is a two-stage voltage application period. Even if multiple stages are adopted, it is effective.

Further, the change prevention period Tr for preventing the change of the current-voltage characteristic of the non-linear resistance element and the data voltage compensation period Td are shorter than the writing period Ts.

FIG. 14 shows a data signal waveform,
The waveforms corresponding to the respective display contents (white, gray, and black display) applied to the positive side field in the standard writing period (1H) are continuously shown. For a plurality of displays from white to black, the voltage applied during the change prevention period Tr is -VB0,-
Three types of VB2 and -VB1 are classified and applied.

Further, as shown in FIG. 14, the data voltage has three kinds of data voltage amplitudes. First, in the change prevention period Tr, −VB0 is used in the case of white display with a small dielectric constant according to the magnitude of the dielectric constant of the liquid crystal. In the case of a halftone (gray) display in which the dielectric constant is intermediate, -VB2 is used. In the case of black display with a large dielectric constant, -VB1 is used.

As described above, since the dielectric constant anisotropy of the liquid crystal can be corrected within the standard writing period (1H), the display content can be easily recognized, and the dielectric constant anisotropy of the liquid crystal can be determined depending on the display content. I can compensate.

Further, in the present invention, as shown in FIG. 14, a constant voltage VB0 is applied during the data voltage compensation period Td. Further, during the initial writing period (T31), a constant voltage (VBM) is similarly applied. This prevents crosstalk depending on the display content.

Further, of the portion corresponding to the writing period Ts, a constant + VBM is applied to the portion corresponding to the initial writing period T31 regardless of the display content. By providing this period, it is possible to further reduce the crosstalk and efficiently control the flow of a rapid current through the nonlinear resistance element at the beginning of the writing period Ts.

In the final writing period T32, + VB3 is applied during white display. + VB when gray is displayed
4 is applied. -VB3 (-VB1) when displaying black
Is applied.

In the fifth embodiment of the present invention, the change prevention voltage Vr, the final write voltage Vs, and the data compensation voltage Vd are applied with the same absolute value. As a result, the scanning signal waveform can be simplified. Further, since a voltage lower than the final writing voltage Vs is applied in the initial writing period T31, it is not necessary to particularly increase the withstand voltage of the integrated circuit (IC) that creates the scanning signal waveform.

The change prevention voltage Vr and the write voltage V
A voltage having the same polarity as that of s is applied, and a voltage having the opposite polarity is applied as the data voltage compensation voltage Vd. The scanning signal waveform includes
The holding voltage Vh is applied during the holding period Th other than the standard writing period (1H).

Regarding the afterimage phenomenon when the driving method shown in the fifth embodiment of the present invention is used, each display is performed for a longer time than in the first embodiment. First of all, the transmittance is 50%
Voltage (V1) displayed for 10 minutes (non-selection period: T1)
Then, apply the voltage (V2) at the display with a transmittance of 10% to 6
The voltage is applied for 00 minutes (selection period: T2), and again, the same voltage (V3) as the voltage (V1) applied during the first non-selection period of T1 is applied for 10 minutes (non-selection period: T3).

The afterimage phenomenon is a phenomenon in which a difference (ΔT) occurs in the transmittance even though the voltages applied to the non-selection period T1 and the non-selection period T3 are equal. By using the driving method according to the fifth embodiment of the present invention, the difference (ΔT) in transmittance can be made extremely small particularly when a display is performed for a long time. At this time, the transmittance difference ΔT in the liquid crystal display device is 0.05%, which can be improved to the extent that it cannot be detected by the naked eye at all.

When the fifth embodiment of the present invention is used, the change in the current-voltage characteristics of the non-linear resistance element due to the displayed contents at the initial stage and after the display of the transmittance of 10% for 600 minutes is as follows. It is extremely small as in the embodiment.

Further, during the data voltage compensation period Td,
Be sure to apply a constant voltage VBM that does not depend on the displayed contents,
Furthermore, since the data signal waveform that does not depend on the display content is used in the initial writing period 1, the delay of the waveform of the data signal waveform can be made constant. Therefore, it is possible to reduce the change in the image depending on the display content, so-called crosstalk.

As is apparent from the above description, even when a constant display is performed for a long time by using the fifth embodiment, almost all the current-voltage characteristics of the non-linear resistance element depending on the display content are generated. Never.

[0161]

As is apparent from the above description, by using the driving waveform of the present invention, the scanning signal waveform applied to the scanning signal electrode can be written in the writing period Ts and the data voltage compensation period Td in the standard writing period (1H). And a change prevention period Tr for preventing a change in the current-voltage characteristics of the nonlinear resistance element
And has a holding period Th.

As a result, the desired display is performed by the combination of the write period Ts of the scanning signal waveform and the data signal waveform, and the change prevention voltage Vr is changed in the change prevention period Tr for preventing the change of the current-voltage characteristic of the nonlinear resistance element.
By applying, it is possible to prevent the change of the current-voltage characteristic of the non-linear resistance element depending on the display content.

Further, in the change prevention period Tr, voltages having different voltage amplitudes are applied to compensate the dielectric anisotropy of the liquid crystal.
By using a small voltage amplitude when the dielectric constant of the liquid crystal is large and a large voltage amplitude when the dielectric constant is small, the current of the non-linear resistance element that depends on the displayed contents is particularly large when the non-linear resistance element is used. -The difference between changes in voltage characteristics can be made extremely small.

Further, the current flowing through the non-linear resistance element is controlled to be small at the beginning of the writing period Ts by adopting the stepwise or gradually increasing the final writing voltage from the initial writing voltage of the writing period Ts. You can Further, it can be further improved by making the data signal waveform in the initial writing period constant independent of the display content.

Furthermore, in the present invention, by providing the data voltage compensation period Td, it is possible to prevent the deviation of the data voltage due to the display contents. Therefore, it is possible to prevent charges accumulated in the liquid crystal during the writing period Ts from changing through the nonlinear resistance element during the holding period Th depending on the display content.

Further, a plurality of change prevention periods Tr for preventing the change of the current-voltage characteristics of the non-linear resistance element are provided before the writing period Ts. As a result, in the driving method of the present invention, the change of the current-voltage characteristics of the non-linear resistance element can be efficiently prevented at a low voltage.

Furthermore, the current of the non-linear resistance element −
The change prevention period Tr for preventing the change of the voltage characteristic is set to be shorter than the writing period Ts or the data voltage compensation period Td. As a result, in the present invention, it is possible to prevent the change in the current-voltage characteristics of the non-linear resistance element without degrading the display quality.

Further, the change prevention voltage Vr applied in the change prevention period Tr for preventing the change of the current-voltage characteristic of the nonlinear resistance element is more than the voltage Vs applied in the write period Ts or the voltage Vd applied in the data voltage compensation period Td. Also applies a large voltage.

As a result, in the driving method of the present invention, a current can be efficiently passed through the non-linear resistance element. Therefore, the change of the current-voltage characteristics of the non-linear resistance element can be efficiently and stably prevented and uniformly prevented in a short time, and the deterioration of contrast, the flicker phenomenon and the image sticking phenomenon can be prevented, and a good image can be obtained. A method for driving a liquid crystal display device having high quality can be provided.

[Brief description of drawings]

FIG. 1 is a waveform diagram showing a scanning signal waveform, showing a driving method of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a data signal waveform, showing a driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 3 is a graph showing changes in current-voltage characteristics of a non-linear resistance element when the driving method of the liquid crystal display device according to the embodiment of the present invention is used.

FIG. 4 is a graph showing a burn-in amount of the liquid crystal display device when the driving method of the liquid crystal display device according to the embodiment of the present invention is used.

FIG. 5 is a waveform diagram showing a scanning signal waveform, showing a driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 6 is a waveform diagram showing a data signal waveform, showing the driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 7 is a waveform diagram showing a scanning signal waveform, showing a driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 8 is a waveform diagram showing a data signal waveform, showing a driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 9 is a waveform diagram showing a scanning signal waveform, showing a driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 10 is a waveform diagram showing a data signal waveform, showing a driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 11 is a graph showing the relationship between the applied voltage and the transmittance of liquid crystal and the relationship between the applied voltage and the dielectric constant.

FIG. 12 is a circuit diagram showing an electrically equivalent configuration of a liquid crystal and a non-linear resistance element.

FIG. 13 is a waveform diagram showing a scanning signal waveform, showing the driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 14 is a waveform diagram showing a data signal waveform, showing the driving method of the liquid crystal display device according to the embodiment of the present invention.

FIG. 15 is a plan view showing a configuration of a liquid crystal display panel including a non-linear resistance element.

FIG. 16 is a cross-sectional view showing a configuration of a liquid crystal display panel including a non-linear resistance element.

FIG. 17 is an equivalent circuit diagram showing a configuration of a liquid crystal display panel including a non-linear resistance element.

FIG. 18 is a waveform diagram showing a scanning signal waveform, showing the driving method of the liquid crystal display device in the related art.

FIG. 19 is a waveform diagram showing a data signal waveform, showing the driving method of the liquid crystal display device in the related art.

FIG. 20 is a graph showing a burn-in amount of a liquid crystal display device when a driving method of a liquid crystal display device according to a conventional technique is used.

FIG. 21 is a graph showing a change in current-voltage characteristics of a non-linear resistance element when a driving method of a liquid crystal display device according to a conventional technique is used.

[Explanation of symbols]

 Ts write time Tr change prevention period Td data voltage compensation period Th retention period + Vs write voltage −Vs write voltage + Vr change prevention voltage −Vr change prevention voltage + Vd data voltage compensation voltage −Vd data voltage compensation voltage + Vh retention voltage −Vh retention voltage + VD1 Data voltage −VD1 Data voltage T31 Initial writing period T32 Last writing period SN Scan signal electrode DN Data electrode

Claims (11)

[Claims] 1. A writing voltage Vs is applied to a non-linear resistance element arranged in a matrix during a writing period Ts via a scanning signal and a data signal, and a holding voltage Vs is held during a holding period Th.
The driving method of the liquid crystal display device having a non-linear resistance element in which h is applied to the liquid crystal through the non-linear resistance element, and the current-voltage characteristic of the non-linear resistance element changes according to the current flowing through the non-linear resistance element, the scanning signal A data voltage compensation period T having a write voltage Vs at Ts and a change prevention voltage Vr at a change prevention period Tr for preventing a change in current-voltage characteristics of a non-linear resistance element and preventing a bias of the data voltage.
A method of driving a liquid crystal display device, wherein d has a data compensation voltage Vd. 2. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs during a writing period Ts via a scanning signal and a data signal, and a holding voltage during a holding period Th is applied to a liquid crystal through a non-linear resistance element. In the driving method of the liquid crystal display device having the non-linear resistance element, the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element.
s, has a change prevention voltage Vr in a change prevention period Tr for preventing a change in the current-voltage characteristic of the non-linear resistance element, and has a data compensation voltage Vd in a data voltage compensation period Td for preventing data voltage bias. The method for driving a liquid crystal display device, wherein the change prevention voltage Vr is a voltage higher than the write voltage Vs, and the data compensation voltage Vd is the same voltage with the opposite polarity to the write voltage Vs. 3. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs during a writing period Ts via a scanning signal and a data signal, and a holding voltage during a holding period Th is applied to a liquid crystal through a non-linear resistance element. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. In the signal writing period Ts, the data signal V
D1 is applied, a constant data voltage VD0 is applied during the scan signal change prevention period Tr irrespective of the display content, and an inverted signal of the data signal VD1 of the write period Ts is applied during the data voltage compensation period Td of the scan signal. A method for driving a liquid crystal display device, comprising: 4. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs in a writing period Ts via a scanning signal and a data signal, and a holding voltage is applied in a holding period Th to a liquid crystal via a non-linear resistance element. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. In the signal writing period Ts, the data signal V
Ds is applied, the maximum amplitude VD1 of the data voltage is applied in the scan signal change prevention period Tr, and the data signal VD of the write period Ts is applied in the scan signal data voltage compensation period Td.
A method for driving a liquid crystal display device, which comprises applying an inverted signal of s. 5. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs during a writing period Ts via a scanning signal and a data signal, and a holding voltage during a holding period Th is applied to a liquid crystal through a non-linear resistance element. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. A liquid crystal table characterized in that the maximum amplitude of the data voltage is different between the signal writing period Ts, the change prevention period Tr, and the data voltage compensation period Td. Method of driving the display device. 6. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs during a writing period Ts via a scanning signal and a data signal, and a holding voltage during a holding period Th is applied to a liquid crystal through a non-linear resistance element. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. In the signal writing period Ts, the data signal V
During the scan signal change prevention period Tr, a large voltage VB0 is applied when the capacitance of the liquid crystal is small, and a small voltage VB1 is applied when the capacitance is large during the scan signal change prevention period Tr, and during the scan signal data voltage compensation period Td. A method for driving a liquid crystal display device, which comprises applying a constant data voltage VB3. 7. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs during a writing period Ts via a scanning signal and a data signal, and a holding voltage during holding period Th is applied to a liquid crystal through a non-linear resistance element. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. In the signal writing period Ts, the data signal V
During the scan signal change prevention period Tr, a large voltage VB0 is applied when the capacitance of the liquid crystal is small, and a small voltage VB1 is applied when the capacitance is large during the scan signal change prevention period Tr, and during the scan signal data voltage compensation period Td. A method for driving a liquid crystal display device, which comprises applying an inverted signal of the data signal VD1 in the writing period Ts. 8. A write voltage Vs is applied to a non-linear resistance element arranged in a matrix in a write period Ts via a scanning signal and a data signal, and a hold voltage is applied to a liquid crystal via a non-linear resistance element in a hold period Th. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. In the signal writing period Ts, the data signal V
Ds is applied, the middle amplitude VD2 of the data voltage is applied during the scan signal change prevention period Tr, and the data signal V of the write period Ts is applied during the data voltage compensation period Td of the scan signal.
A driving method of a liquid crystal display device, wherein an inversion signal of Ds is applied, and a scanning signal has a change prevention voltage Vr in a plurality of change prevention periods Tr for preventing a change in current-voltage characteristics of a non-linear resistance element. . 9. A non-linear resistance element arranged in a matrix is applied with a writing voltage Vs during a writing period Ts via a scanning signal and a data signal, and a holding voltage during holding period Th is applied to a liquid crystal through a non-linear resistance element. The driving method of a liquid crystal display device having a non-linear resistance element in which the current-voltage characteristic of the non-linear resistance element changes according to the current flowing in the non-linear resistance element, the scanning signal has the write voltage Vs in the write period Ts. The non-linear resistance element has the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic, and the data compensation voltage Vd in the data voltage compensation period Td for preventing the bias of the data voltage, and the data signal is scanned. In the signal writing period Ts, the data signal V
During the scan signal change prevention period Tr, a large voltage VB0 is applied when the capacitance of the liquid crystal is small, and a small voltage VB1 is applied when the capacitance is large during the scan signal change prevention period Tr, and during the scan signal data voltage compensation period Td. A constant data voltage VB0 is applied, and the scanning signal is applied to the data voltage compensation voltage Vd during a plurality of data voltage compensation periods Td.
A method for driving a liquid crystal display device, comprising: 10. A writing period Ts is applied to a non-linear resistance element arranged in a matrix through a scanning signal and a data signal.
To the liquid crystal through the non-linear resistance element during the holding period Th, and the current-voltage characteristic of the non-linear resistance element changes depending on the current flowing through the non-linear resistance element. According to the driving method of the liquid crystal display device, the scan signal has the write voltage Vs in the write period Ts and the change prevention voltage Vr in the change prevention period Tr for preventing the change of the current-voltage characteristic of the nonlinear resistance element. Data voltage compensation period T to prevent bias
A liquid crystal having a data compensation voltage Vd in d, and a change prevention period Tr for preventing a change in the current-voltage characteristic of the non-linear resistance element is shorter than the writing period Ts and the data voltage compensation period Td. Driving method of display device. 11. The voltage VS1 lower than the write voltage Vs is applied at the beginning of the scan signal write period Ts, as described in any one of claims 1, 2, 3, 4, 5, 6, 7.
11. A method for driving a liquid crystal display device described in 8, 9, or 10.