JPH1145075A - Driving method for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve picture quality by completing the compensation of scan distortion voltage caused by switching of the polarity of signal voltage at a signal electrode in one horizontal synchronizing period. SOLUTION: When scan distortion voltage in a scanning side dummy electrode X0 is detected by a compensation voltage generating circuit 3 and compensation voltage is generated, the compensation voltage is reversed and added to a scanning voltage non-selection potential VM generated by a scanning voltage-non-selection potential generating circuit 2, and compensation is performed, a power operational amplifier 12 for compensating voltage is used for an element performing this inversion and addition and this compensation is finished in one horizontal synchronizing period in which scan distortion voltage is generated. Therefore, since compensation voltage does not reach the next horizontal synchronizing period, as effective voltage of pixel applying voltage in the next horizontal synchronizing period is not affected, scan distortion voltage can be compensated without degrading picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly to a method of driving a simple matrix type liquid crystal display having a matrix pixel structure.

[0002]

2. Description of the Related Art In recent years, the display capacity of a liquid crystal display device has been dramatically increased, and the liquid crystal display device has been widely used as a display for a personal computer, a monitor, or the like by utilizing its thin and lightweight features. Among them, a super twisted nematic (hereinafter, referred to as STN) liquid crystal display device is characterized by being relatively inexpensive and capable of obtaining good display characteristics.

In a simple matrix type liquid crystal display device such as the STN described above, a driving method generally called a voltage averaging method is used, and each pixel of the liquid crystal responds to an effective voltage of a pixel applied voltage. However, in an actual liquid crystal panel, the scanning voltage is distorted due to the influence of the differential distortion voltage from the counter electrode due to the capacitance component of the liquid crystal. For this reason, the effective voltage applied to each pixel deviates from the ideal value, and display unevenness called crosstalk occurs.

Hereinafter, a driving method of a conventional STN type liquid crystal display device will be described with reference to the drawings. FIG. 6 shows ST
It is a schematic diagram which shows the drive method of an N-type liquid crystal display device. In the figure, reference numeral 1 denotes a 3 dot × 4 dot liquid crystal panel.
In the liquid crystal panel 1, X0 is a scanning-side dummy electrode, X1
X4 is a scanning electrode, Y1 to Y3 are signal electrodes, V (X1)
V (X4) is a scanning voltage, V (Y1) to V (Y3) are signal voltages, Va is a positive differential distortion voltage, Vb is a negative differential distortion voltage,
Vc indicates a scanning distortion voltage, and Vrev indicates an AC inversion signal. VR minus or V is applied to each of the scanning electrodes X1 to X4.
The R-plus scanning voltages V (X1) to V (X2) are sequentially applied to turn on / off the display of the pixel on the selected scanning electrode.
Signal voltages V (Y1) to V (Y3) corresponding to the OFF state are applied to respective signal electrodes Y1 to Y3. Here, t indicates the elapsed time.

At this time, the AC inversion signal Vrev becomes "L".
, The scanning voltage selection potential is VR minus, the signal voltage is VC plus when on, and VC minus when off, and when the AC inversion signal Vrev is “H”, the scanning voltage selection potential is VR plus and the signal The voltage is VC minus when turned on, and VC plus when turned off. According to this, in the display in FIG. 6, in the line of the signal electrode Y1 and the signal electrode Y3, all the four pixels from the top are turned off, and in the line of the signal electrode Y2, the three pixels from the top are turned on and the fourth is displayed. Are off display. When the above-mentioned display is performed, the differential distortion voltage is applied to the scanning electrode from the signal electrode via the liquid crystal at the timing when the AC inversion signal Vrev switches from "L" to "H".

In the line of the signal electrode Y1 and the signal electrode Y3, the signal voltage switches from VC minus to VC plus, so that the differential distortion voltage applied to the scanning electrode becomes a positive differential distortion voltage Va. In the signal electrode Y2 line, the signal voltage switches from VC plus to VC minus, so that the differential distortion voltage applied to the scanning electrode becomes the negative differential distortion voltage Vb.
At this time, the magnitude of the differential distortion voltage is larger for the positive differential distortion voltage applied from the two lines of the signal electrode Y1 and the signal electrode Y3, and finally the positive differential distortion voltage is applied to the scan electrode. , A scanning distortion voltage Vc is generated.

FIG. 7 is a waveform diagram showing each signal in the line of the scanning electrode X4. Note that the same reference numerals are given to the same contents as those in FIG. In the figure, V
(X4) is a scanning voltage at which a scanning distortion voltage is generated by the differential distortion voltage from the signal electrode, V (X4Y1) is a pixel applied voltage to a pixel between the scanning electrode X4 and the signal electrode Y1, d1 is a voltage distortion portion, V (X4Y2) is a pixel applied voltage to a pixel between the scanning electrode X4 and the signal electrode Y2, d2 is a voltage distorted portion, V
(X4Y3) is a pixel applied voltage to a pixel between the scanning electrode X4 and the signal electrode Y3, and d3 is a voltage distortion portion.

In FIG. 7, in the voltage distortion portion d1 and the voltage distortion portion d3, the effective voltage decreases, but in the voltage distortion portion d2, the effective voltage increases. As a result, while all the pixels are in the off-display state, only the effective voltage to the pixels between the scanning electrode X4 and the signal electrode Y2 is increased, causing display unevenness and crosstalk.

Conventionally, in order to reduce this phenomenon, a scanning-side dummy electrode X0 shown in FIG. 6 is provided, a scanning distortion voltage to the scanning electrode is detected from a potential change thereof, and the detected scanning distortion voltage is inverted. Means for compensating for the scanning distortion voltage by adding it to the scanning voltage non-selection potential (hereinafter, this method is referred to as feedback compensation) is used.
No. 899 discloses an example.

FIG. 8 shows a configuration of a feedback compensation circuit of a conventional liquid crystal display device. In the drawing, X0 is a scanning side dummy electrode, 2 is a scanning voltage non-selection potential generating circuit for generating a scanning voltage non-selection potential VM, and 3 is a potential change of the scanning side dummy electrode X0 based on the scanning voltage non-selection potential VM. A compensation voltage generation circuit for detecting and generating a compensation voltage; 4, a scanning voltage non-selection potential compensation circuit for inverting and adding the compensation voltage to a scanning voltage non-selection potential VM for compensation; and 5, a compensated scanning voltage non-selection potential. Is a scan driver that generates and drives a scan voltage for each scan electrode based on the scan voltage. In the compensation voltage generating circuit 3, reference numerals 6 and 7 denote distortion voltage adjustment resistors, and reference numeral 8 denotes a distortion voltage detecting operational amplifier having a gain set to 1. Further, in the scanning voltage non-selection potential compensating circuit 4, reference numerals 9 and 10 denote compensation resistors for adjusting a compensation voltage, and reference numeral 11 denotes a voltage compensating operational amplifier for inverting and adding a compensation voltage to the scanning voltage non-selection potential.

The operation of the above configuration will be described. The scanning distortion voltage applied to the scanning-side dummy electrode X0 is adjusted by the distortion voltage adjusting resistor 6 and the distortion voltage adjusting resistor 7 of the compensation voltage generating circuit 3, and is supplied to the scanning voltage non-selection potential via the distortion voltage detecting operational amplifier 8. The voltage is output to the compensation circuit 4, adjusted by the compensation voltage adjustment resistors 9 and 10 of the scanning voltage non-selection potential compensation circuit 4, and inverted and added to the scanning voltage non-selection potential by the voltage compensation operational amplifier 11 for scanning. Output to the driver 5. The scan driver 5 drives the liquid crystal panel 1 by applying a scan voltage generated based on the compensated scan voltage non-selection potential to the liquid crystal panel 1.

FIG. 9 is a waveform diagram showing each signal voltage of the line of the scanning electrode X4 in FIG. 6 at this time. In addition,
The same reference numerals are given to the same contents as those in FIG. 7 and the description is omitted. Here, Vd is a compensation voltage.

The compensation voltage Vd is an effective voltage between the voltage applied to the pixel between the scan electrode X4 and the signal electrode Y1 and the voltage applied to the pixel between the scan electrode X4 and the signal electrode Y3. In the direction in which the effective voltage decreases in the voltage applied to the pixel between the scanning electrode X4 and the signal electrode Y2. As a result, the scanning distortion voltage due to the switching of the signal voltage is canceled out, the effective voltage to each pixel becomes equal, and a uniform display can be obtained.

[0014]

In such a conventional method of driving a liquid crystal display device, the compensation of the effective voltage cannot be completed within one horizontal synchronization period, and is shifted to the next horizontal synchronization period. Deviates from the desired effective voltage.

FIG. 10 is a waveform diagram showing an operation at the time of scanning voltage non-selection potential compensation by the conventional feedback compensation circuit shown in FIG. Now, the line of the scanning electrode X1 is set as an off display line, the signal voltage V (Y1) shown in FIG. 10C is applied to the signal electrode Y1, and the signal voltage V (Y) shown in FIG. Suppose that scanning is performed in synchronization with the horizontal synchronizing signal VH shown in FIG.
At this time, the scanning distortion voltage Vc when the signal voltage V (Y1) and the signal voltage V (Y2) are switched at the timing synchronized with the horizontal synchronizing signal VH is detected by the scanning side dummy electrode X0, and is shown in FIG. The compensation voltage Vd is added and compensated by the feedback compensation circuit. However, as shown in FIG. 10A, the compensation voltage Vd reaches the horizontal synchronization period T2 following the horizontal synchronization period T1. In the horizontal synchronizing period T2, the effective voltage applied by the signal voltage V (Y1) of the signal electrode Y1 and the scanning voltage V (X1) of the off display line decreases, while the signal voltage V of the signal electrode Y2 decreases. (Y2) and the scanning voltage V (X
The effective voltage applied in 1) increases in the direction described above, and there is a problem that the display becomes non-uniform due to a difference in luminance due to the difference in the effective voltage even though both pixels are in the off display. Was.

The present invention solves the above-mentioned problems, and eliminates non-uniformity of display by voltage compensation of a scanning voltage non-selection potential performed in response to a scanning distortion voltage due to switching of a signal voltage, thereby improving image quality. It is an object of the present invention to provide a method for driving a liquid crystal display device.

[0017]

According to a first aspect of the present invention, in a liquid crystal display device in which scanning electrodes and signal electrodes are arranged in a matrix, a scanning voltage is applied to the scanning electrodes and a signal is applied to the signal electrodes. When driving by applying a signal voltage, a scanning distortion voltage superimposed on the scanning voltage via liquid crystal due to a change in the polarity of the signal voltage is detected by a potential change of an auxiliary scanning electrode, and the detected scanning distortion voltage is scanned. The voltage non-selection potential compensating circuit inverts and superimposes the scanning voltage on the scanning voltage non-selection potential, thereby compensating for the fluctuation of the effective voltage of the scanning voltage. A driving method of a liquid crystal display device, wherein the compensation operation is completed within a horizontal synchronization period in which a distortion voltage is generated.

According to the present invention, the compensation of the scanning voltage non-selection potential can be completed within one horizontal synchronization period, and the image quality can be improved.

According to a second aspect of the present invention, in a liquid crystal display device in which scanning electrodes and signal electrodes are arranged in a matrix, a scanning voltage is applied to the scanning electrodes and a signal voltage is applied to the signal electrodes. When driving, a scanning distortion voltage superimposed on the scanning voltage via the liquid crystal due to a polarity change of the signal voltage is detected by a potential change of an auxiliary scanning electrode, and the detected scanning distortion voltage is used as a scanning voltage non-selection potential compensation circuit. And compensates for the variation of the effective voltage of the scanning voltage by superimposing the scanning voltage on the scanning voltage non-selection potential. This is a method for driving a liquid crystal display device that is used by switching to a scanning voltage non-selection potential of a selection potential generation circuit.

According to the present invention, the compensation of the scanning voltage non-selection potential can be always completed within one horizontal synchronization period to improve the image quality without using a power operational amplifier and thus suppressing an increase in power.

According to a third aspect of the present invention, a scan driver for generating a scan voltage based on a scan voltage non-selection potential includes a scan voltage non-selection potential generated by a scan voltage non-selection potential generation circuit and a compensated scan voltage. A voltage non-selection potential is input, and a scan voltage non-selection potential compensated only during a horizontal synchronization period in which a scan distortion voltage is generated is used by switching to a scan voltage non-selection potential of a scan voltage non-selection potential generation circuit. A method for driving a liquid crystal display device according to claim 2.

As a result, the overall configuration can be simplified.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Hereinafter, Embodiment 1 of a method for driving a liquid crystal display device of the present invention will be described with reference to the drawings. In the present embodiment, a power operational amplifier is employed as an operational amplifier for inverting and adding a scanning distortion voltage to a scanning voltage non-selection potential, so that compensation is completed within one horizontal synchronization period.

FIG. 1 is a block diagram showing a configuration of a feedback compensation circuit according to the present embodiment. FIG.
The same reference numerals are given to the same contents and description thereof is omitted. This embodiment differs from the feedback compensation circuit shown in FIG. 8 in that a voltage compensation power operational amplifier 12 is used in place of the voltage compensation operational amplifier 11 in the scanning voltage non-selection potential compensation circuit 4.

The operation of the above configuration will be described. The scanning distortion voltage applied to the scanning-side dummy electrode X0 is adjusted by the distortion voltage amount adjusting resistor 6 and the distortion voltage amount adjusting resistor 7 in the compensation voltage generating circuit 3, and is applied as a compensation voltage via the distortion voltage detecting operational amplifier 8 to the scanning voltage. It is output to the non-selection potential compensation circuit 4. The scanning voltage non-selection potential compensating circuit 4 adjusts the compensating voltage by using a compensating voltage amount adjusting resistor 9 and a compensating voltage amount adjusting resistor 10, and adjusts the voltage compensating power operational amplifier 12.
, And inverts and adds to the scanning voltage non-selection potential VM, and applies the scanning driver 5 to the liquid crystal panel.

FIG. 2 is a waveform diagram showing an operation at the time of scanning voltage non-selection potential compensation in this embodiment. Note that FIG.
The same reference numerals are given to the same contents as in the conventional example shown in FIG. The scanning distortion voltage Vc when the signal voltage V (Y1) and V (Y2) are switched at the timing synchronized with the horizontal synchronizing signal VH is detected by the scanning side dummy electrode X0, and is compensated by the feedback compensation circuit shown in FIG. The voltage Vd is added and compensated. In the present embodiment, as shown in FIG. 2A, the compensation voltage Vd is adjusted by the voltage compensation power operational amplifier 12 in the next horizontal synchronization at the time of voltage compensation. The voltage is applied only during the horizontal synchronizing period T1 during voltage compensation without affecting the period T2. This allows
The effective voltage applied by the signal voltage V (Y1) of the signal electrode Y1 and the scan voltage V (X1) of the off display line, the signal voltage V (Y2) of the signal electrode Y2 and the scan voltage V (X1) of the off display line ), The effective voltage applied is equal to each other, and the display non-uniformity generated at the time of scanning voltage non-selection potential compensation is eliminated, crosstalk is compensated for without deteriorating the image quality, and the image quality is improved. it can.

(Embodiment 2) Hereinafter, a second embodiment of a method of driving a liquid crystal display device according to the present invention will be described with reference to the drawings. In the present embodiment, a switching between a compensated scanning voltage non-selection potential obtained by inverting and adding a scanning distortion voltage to a scanning voltage non-selection potential and a normal scanning voltage non-selection potential generated by a scanning voltage non-selection potential generation circuit is performed. By switching and using the compensated scanning voltage non-selection potential only within one horizontal period in which the scanning distortion voltage is generated, the compensation always ends within one horizontal synchronization period.

FIG. 3 is a block diagram showing a configuration of the feedback compensation circuit according to the present embodiment. FIG.
The same reference numerals are given to the same contents and description thereof is omitted. In FIG. 3, 13 is a scanning voltage non-selection potential changeover switch, and 14 is a compensation period control signal generation circuit.

The operation of the above configuration will be described. The scanning distortion voltage applied to the scanning-side dummy electrode X0 is adjusted by the distortion voltage adjusting resistor 6 and the distortion voltage adjusting resistor 7 of the compensation voltage generating circuit 3, and the scanning voltage is applied via the distortion voltage detecting operational amplifier 8 as a compensation voltage. It is output to the non-selection potential compensation circuit 4. The scanning voltage non-selection potential compensating circuit 4 converts the compensation voltage into a compensation voltage adjustment resistor 9 and a compensation voltage adjustment resistor 10.
, And is inverted and added to the scanning voltage non-selection potential by the voltage compensation operational amplifier 11, and is output to the scanning driver 5 via the scanning voltage non-selection potential switch 13. On the other hand, the compensation period control signal generation circuit 14 generates a compensation period control signal Vcont which becomes “H” in response to the inversion of the signal voltages of the signal electrodes Y 1 and Y 2, Open / close is controlled, and the scanning voltage non-selection potential changeover switch 13 sets the compensation period control signal Vcont to '
Only when H ′, the output of the scanning voltage non-selection potential compensating circuit 4 is input to the scanning driver 5, and the compensation period control signal Vcont
In the case of L ′, switching is performed so that the scanning voltage non-selection potential VM of the scanning voltage non-selection potential generating circuit 2 is input to the scanning driver 5.

FIG. 4 is a waveform diagram showing an operation at the time of scanning voltage non-selection potential compensation by the feedback compensation circuit according to the second embodiment. The same reference numerals are given to the same contents as those in FIG. FIG. 4E shows the compensation period control signal Vcont.

The scanning distortion voltage Vc when the signal voltage V (Y1) and the signal voltage V (Y2) are switched at the timing synchronized with the horizontal synchronizing signal VH is detected by the scanning side dummy electrode X0, and is shown in FIG. The compensation voltage Vd is added and compensated by the feedback compensation circuit. In the present embodiment, as shown in FIG. 4A, the scanning voltage non-selection potential switch 13 switches the horizontal synchronization period during voltage compensation. T
Only 1 is output to the scanning driver 5 and is switched to the scanning voltage non-selection potential VM of the scanning voltage non-selection potential generating circuit 2 in the next horizontal synchronization period T2 at the time of voltage compensation without voltage compensation.

Therefore, the compensation voltage Vd is applied during the horizontal synchronization period T1 during the voltage compensation without affecting the next horizontal synchronization period T2 during the voltage compensation, and is applied to the signal voltage V (Y1) of the signal electrode Y1. The effective voltage applied by the scan voltage V (X1) of the off display line is equal to the effective voltage applied by the signal voltage V (Y2) of the signal electrode Y2 and the scan voltage V (X1) of the off display line. Become. This eliminates the need for a power operational amplifier for voltage compensation, and therefore eliminates non-uniformity of display that occurs during voltage compensation of the scanning voltage non-selection potential without increasing power, and compensates for crosstalk without deteriorating image quality. In addition, the image quality can be improved.

In the above description, it has been described that, when the signal from the compensation period control signal generation circuit 14 is "H", the voltage is switched to the scanning voltage non-selection potential which is voltage compensated.
A configuration in which the signal is switched to the voltage-compensated scanning voltage non-selection potential when the signal from the compensation period control signal generation circuit 14 is “L” can be similarly implemented, and a power operational amplifier may be used for voltage compensation. It goes without saying that it is good.

(Embodiment 3) Hereinafter, a third embodiment of a method for driving a liquid crystal display device according to the present invention will be described with reference to the drawings. In the present embodiment, the scan voltage non-selection potential and the normal scan voltage non-selection potential which have been compensated inside the scan driver are switched and used.

FIG. 5 is a block diagram showing a configuration of the feedback compensation circuit according to the third embodiment. In addition, about the same content as FIG. 3, the same code | symbol is attached | subjected and description is abbreviate | omitted. The present embodiment is different from the second embodiment in that the scanning voltage non-selection potential changeover switch 13 and the compensation period control signal generating circuit 14 are provided inside the scanning driver 5. Is the same as in the second embodiment.

According to the present embodiment, the scanning driver 5 is provided with the scanning voltage non-selection potential changeover switch 13 and the compensation period control signal generation circuit 14 to reduce the cost increase and to reduce the scanning voltage non-selection potential. It is possible to eliminate display non-uniformity generated at the time of voltage compensation, compensate for crosstalk without deteriorating image quality, and improve image quality.

[0037]

According to the present invention, in a liquid crystal display device in which scanning electrodes and signal electrodes are arranged in a matrix, a scanning voltage is applied to the scanning electrodes and a signal voltage is applied to the signal electrodes. When driving, a scanning distortion voltage superimposed on the scanning voltage via liquid crystal due to a change in polarity of the signal voltage is detected by a potential change of an auxiliary scanning electrode, and the detected scanning distortion voltage is a scanning voltage non-selection potential. The inversion by the compensation circuit is superimposed on the scanning voltage non-selection potential, thereby compensating for fluctuations in the effective voltage of the scanning voltage, and by using a power operational amplifier in the scanning voltage non-selection potential compensation circuit, a scanning distortion voltage is generated. The driving method of the liquid crystal display device is such that the compensation operation is completed within the horizontal synchronization period, thereby suppressing the voltage compensation period to one horizontal synchronization period. Bets can be, without an indication of non-uniformity occurring when the voltage compensation of the scan voltage non-selection potential, it is possible to improve the image quality.

According to a second aspect of the present invention, in a liquid crystal display device in which scanning electrodes and signal electrodes are arranged in a matrix, a scanning voltage is applied to the scanning electrodes and a signal voltage is applied to the signal electrodes. When driving, a scanning distortion voltage superimposed on the scanning voltage via the liquid crystal due to a polarity change of the signal voltage is detected by a potential change of an auxiliary scanning electrode, and the detected scanning distortion voltage is used as a scanning voltage non-selection potential compensation circuit. And compensates for the variation of the effective voltage of the scanning voltage by superimposing the scanning voltage on the scanning voltage non-selection potential. By adopting a driving method for a liquid crystal display device which is used by switching to a scanning voltage non-selection potential of the selection potential generation circuit, power can be increased without using a power operational amplifier. While suppressing, eliminating the display non-uniformity occurring at the time of voltage compensation of the scan voltage non-selection potential, it is possible to improve the image quality.

According to a third aspect of the present invention, a scan driver for generating a scan voltage based on a scan voltage non-selection potential includes a scan voltage non-selection potential generated by a scan voltage non-selection potential generation circuit and a compensated scan voltage. A voltage non-selection potential is input, and a scan voltage non-selection potential compensated only during a horizontal synchronization period in which a scan distortion voltage is generated is used by switching to a scan voltage non-selection potential of a scan voltage non-selection potential generation circuit. By adopting the driving method of the liquid crystal display device according to the second aspect, the entire configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a feedback compensation circuit according to a first embodiment of a method for driving a liquid crystal display device of the present invention.

FIG. 2 is a waveform chart showing the operation of the embodiment.

FIG. 3 is a block diagram illustrating a configuration of a feedback compensation circuit according to a second embodiment of the driving method of the liquid crystal display device of the present invention.

FIG. 4 is a waveform chart showing the operation of the embodiment.

FIG. 5 is a block diagram illustrating a configuration of a feedback compensation circuit according to a third embodiment of the driving method of the liquid crystal display device of the present invention.

FIG. 6 is a schematic view illustrating a driving method of an STN liquid crystal display device.

FIG. 7 is a waveform chart showing signals on a line of a scanning electrode X4.

FIG. 8 is a block diagram showing a configuration of a feedback compensation circuit in a conventional driving method of a liquid crystal display device.

FIG. 9 is a waveform chart showing signal voltages of a line of a scanning electrode X4 in the conventional example.

FIG. 10 is a waveform chart showing the operation of the conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Scan voltage non-selection potential generation circuit 3 Compensation voltage generation circuit 4 Scan voltage non-selection potential compensation circuit 5 Scan driver 6, 7 Distortion voltage adjustment resistor 8 Distortion voltage detection operational amplifier 9, 10 Compensation voltage adjustment resistor 11 Voltage Compensation Operational Amplifier 12 Voltage Compensation Power Operational Amplifier 13 Scanning Voltage Non-selection Potential Switch 14 Compensation Period Control Signal Generation Circuit d1, d2, d3 Voltage Distortion Part X0 Scanning Dummy Electrode (Auxiliary Scanning Electrode) X1, X2, X3, X4 Scanning electrodes Y1, Y2, Y3 Signal electrode V (X1), V (X2), V (X3), V (X4) Scanning voltage V (Y1), V (Y2), V (Y3) Signal voltage V (X4Y1) , V (X4Y2), V (X4Y3) Pixel applied voltage VM Scanning voltage non-selection potential Va Positive differential distortion voltage Vb Negative differential distortion voltage Vc Scanning distortion voltage Vd Compensation voltage Vrev AC inversion signal VH Horizontal Signal Vcont compensation period control signal T1, T2 horizontal synchronization period

Claims (3)

[Claims] 1. A liquid crystal display device in which a scanning electrode and a signal electrode are arranged in a matrix, wherein the driving device applies a scanning voltage to the scanning electrode and applies a signal voltage to the signal electrode. A scanning distortion voltage superimposed on the scanning voltage via the liquid crystal due to a change in polarity is detected by a potential change of the auxiliary scanning electrode, and the detected scanning distortion voltage is inverted by a scanning voltage non-selection potential compensating circuit to cause the scanning voltage non-selection. By superimposing the effective voltage on the selected potential, the fluctuation of the effective voltage of the scanning voltage is compensated, and by using a power operational amplifier for the scanning voltage non-selected potential compensating circuit, the compensating operation is performed within the horizontal synchronization period in which the scanning distortion voltage is generated. The method of driving a liquid crystal display device, wherein the process is ended. 2. In a liquid crystal display device in which scanning electrodes and signal electrodes are arranged in a matrix, when driving by applying a scanning voltage to the scanning electrodes and applying a signal voltage to the signal electrodes. A scanning distortion voltage superimposed on the scanning voltage via the liquid crystal due to a change in polarity is detected by a potential change of the auxiliary scanning electrode, and the detected scanning distortion voltage is inverted by a scanning voltage non-selection potential compensating circuit to cause the scanning voltage non-selection. The scan voltage non-selection potential is compensated for only within the horizontal synchronization period in which the scan distortion voltage is generated by superimposing the scan voltage non-selection potential on the scan voltage of the scan voltage non-selection potential generation circuit by superimposing the scan voltage on the selection voltage. A method for driving a liquid crystal display device, which is used by switching to a non-selection potential. 3. A scan driver for generating a scan voltage based on a scan voltage non-selection potential inputs a scan voltage non-selection potential generated by a scan voltage non-selection potential generation circuit and a compensated scan voltage non-selection potential. 3. The liquid crystal display according to claim 2, wherein the scan voltage non-selection potential compensated only during the horizontal synchronization period in which the scan distortion voltage is generated is used by switching to the scan voltage non-selection potential of the scan voltage non-selection potential generation circuit. How to drive the device.