JPH03264991A - Driving method for liquid crystal panel - Google Patents

Abstract

PURPOSE:To suppress the generation of a brightness irregularity even when a brightness adjusting voltage is varied by varying a correcting voltage according to the level of the driving voltage of a liquid crystal panel. CONSTITUTION:When a brightness adjusting variable resistor 30 is adjusted to vary the potential VLCD of a power circuit 24, the potential VLCD is inputted to a brightness adjusting voltage converting circuit 31 and the source voltage of a D/A converting circuit 28 is varied with the resistance of the adjusting variable resistor 312 and a reference voltage Vf. Thus, the source voltage is varied to vary even the correcting voltage according to the adjustment of the brightness adjusting variable resistor 30. Consequently, when the brightness adjusting voltage VLCD is low, the correcting voltage becomes small, but when high, the correcting voltage becomes large to perform proper correction corre sponding to the brightness adjusting voltage VLCD. Consequently, A countermea sure to the generation of the brightness irregularity based depending upon a display pattern can be taken even when the brightness adjusting voltage is varied to make a display of good quality.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for driving a liquid crystal panel, when driving a liquid crystal panel with a simple matrix structure using a voltage averaging method, the occurrence of brightness unevenness depending on the display pattern of each line is With the aim of suppressing changes in drive voltage, a matrix type liquid crystal panel in which data electrodes and scan electrodes are provided in an intersecting manner is used with a voltage averaging method that has a positive voltage application mode period and a negative voltage application mode period. For each scan electrode drive time, a correction voltage according to the data displayed on the selected scan electrode is applied to the scan electrode or data electrode with opposite polarity during the positive voltage application mode period and the negative voltage application mode period. In a liquid crystal panel driving method in which crosstalk is removed by adding the selected voltage or non-selected voltage with the same polarity or opposite polarity, the correction voltage is changed according to the magnitude of the liquid crystal panel driving voltage. .

[Industrial application field]

The present invention relates to a method and device for driving a liquid crystal panel having a simple matrix structure.

2. Description of the Related Art In recent years, with the spread of personal computers, word processors, etc., liquid crystal display devices, which are lightweight, thin, and can be powered by batteries, have been increasingly adopted as display devices in place of large, power-consuming CRTs. Driving methods for liquid crystal display devices are broadly divided into simple matrix type and active matrix type, but active matrix type requires a non-linear element for each pixel, making it difficult to manufacture.Currently, liquid crystal display devices with large display capacity Display devices generally employ a simple matrix structure.

However, in display devices with a simple matrix structure, as the display capacity is increased, display unevenness (crosstalk) that depends on the display pattern occurs due to its characteristics, and the display quality deteriorates.Therefore, it is strongly desirable to eliminate this display unevenness. It is rare.

[Conventional technology]

FIG. 11 shows that in the liquid crystal panel with the simple matrix structure shown in FIG. 12, when "bright" is written to all the liquid crystal display elements in one row such as the X1 column and the X2 column (the liquid crystal display is O), This shows the driving waveform of the liquid crystal panel when writing is performed (the liquid crystal display is -). In the figure, (a) shows the data voltage application waveform (
(thick line), data voltage application waveform (dotted line) for column X2,
(b) is Y.

(C) is the scan voltage application waveform of the 72nd row; (d) is the drive voltage waveform of cell α (
(thick line), and the driving voltage waveform of cell β (dotted line).

Note that conventional driving methods employ the voltage averaging method shown in FIG. 13, in which the first period is selected during one frame period and the second period is selected in the next frame, Devices that switch between the first period and the second period every few lines are in practical use, preventing direct current components from being applied to the liquid crystal, and achieving highly reliable driving that does not deteriorate panel characteristics.

This switching between the first period and the second period is called polarity inversion, and the control signal thereof is called a polarity inversion signal.

By the way, in a conventional liquid crystal display device having a simple matrix structure, it is known that as the display capacity is increased, display unevenness (crosstalk) depending on the display pattern occurs due to its characteristics, and the display quality deteriorates. This crosstalk includes a first crosstalk as shown in FIG. 5 and a second crosstalk as shown in FIG.

The first crosstalk shown in FIG. 5(a) is between the r-bright J display cell A on the scan electrode that often displays "dark" and the r-bright display cell B on the scan electrode that often displays "bright". In this case, there is a difference in brightness even in the same "bright" display.

In addition, the second crosstalk shown in Figure 6(a) occurs when "bright" and "dark" horizontal striped patterns on the same scan electrode are repeatedly displayed with different phases and widths. There is a difference in brightness between the cell C on the narrow data electrode and the cell D on the wide data electrode for "dark" display.

Therefore, as a first method to eliminate crosstalk, a liquid crystal panel driving method that counts the number when a certain line is selected and superimposes a correction voltage corresponding to that value on the selection voltage of the scan electrode driver, or The driving method is to add the selection voltage of the data electrode, the non-selection voltage of the data electrode, and the non-selection voltage of the scan electrode, or the reverse method of adding to the selection voltage of the scan electrode and the selection voltage of the scan electrode. The applicant has proposed a driving method in which the select voltage of the data electrode, the non-select voltage of the data electrode, and the non-select voltage of the scan electrode are added in terms of polarity.Also, as a method to eliminate the second crosstalk, the scan When selecting an electrode and selecting the next scan electrode,
The number of times the display data changed from “1” to “O” and “0”
A liquid crystal panel driving method that calculates the difference in the number of changes from 1 to 1 and superimposes a corresponding correction voltage on the non-selection voltage of the scan electrode driver, or a liquid crystal display that superimposes the selection voltage and non-selection voltage of the data electrode. The applicant has proposed a method for driving the panel.

Incidentally, in an actual liquid crystal display device, in order to set the driving voltage, a brightness adjustment circuit is provided so that the display brightness can be adjusted according to the surrounding brightness. This brightness adjustment circuit includes a variable resistor (brightness adjustment volume) provided between the DC power supply VEE and ground, and the drive voltage of the liquid crystal cell is set by the variable output voltage V LCD. For example, if you adjust the brightness adjustment volume in the direction of increasing the output voltage (hereinafter referred to as brightness adjustment voltage) of the brightness adjustment circuit VLCD, the voltage applied to the liquid crystal cell will increase and the display brightness of the cell will increase; When the brightness adjustment volume is adjusted in the direction of decreasing the brightness adjustment voltage V LCD, the voltage applied to the liquid crystal cell becomes smaller and the display brightness of the cell becomes lower.

[Problem to be solved by the invention]

However, when the display brightness of the liquid crystal panel is changed, there is a problem that crosstalk cannot be completely prevented with the above-mentioned correction voltage (which is referred to as ΔVm). For example, when the first crosstalk is taken care of using the above-mentioned correction voltage, the transmittance-drive voltage characteristic (TV characteristic) when the light transmittance of cells A and B is measured by changing the brightness adjustment voltage is calculated as follows. Figure 5 ('b
). As shown in this figure, liquid crystal cell A (indicated by a dotted line curve) in an area where no crosstalk occurs, and liquid crystal cell B in an area where crosstalk occurs and becomes dark.
(shown by the solid line curve), the angle of inclination of the TV characteristic is large, so the brightness adjustment voltage VLCD is
Only when set to I, the occurrence of wolfberry talk can be prevented.

Similarly, in the second case of crosstalk, the TV characteristics of liquid crystal cell D are more inclined than those of liquid crystal cell C where crosstalk occurs, and even after countermeasures, it becomes dark (Fig. 6(b)). As shown in FIG. 2, the TV characteristics do not match except for the brightness adjustment voltage VLCD at VLCD4, and when the brightness adjustment voltage VLCD is changed, there is a problem in that crosstalk occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal panel driving method that solves the problems with the conventional simple matrix type liquid crystal display device and can suppress the occurrence of brightness unevenness even when the brightness adjustment voltage is changed. It is.

[Means to solve the problem]

A liquid crystal panel driving method of the present invention that solves the above-mentioned conventional problems includes a matrix type liquid crystal panel in which data electrodes and scan electrodes are provided to intersect with each other, and has a positive voltage application mode period and a negative voltage application mode period. In the method of driving using the voltage averaging method, in the first form, as shown in FIG.
For each scan electrode driving time, a correction voltage is determined according to the data to be displayed on the selected scan electrode, and then the correction voltage is corrected according to the magnitude of the driving voltage of the liquid crystal panel, and the corrected correction voltage is has opposite polarity during the positive voltage application mode period and the negative voltage application mode period, and is added to the selection voltage or non-selection voltage of the scan electrode or data electrode with the same or opposite polarity.

[Effect]

According to the present invention, when the correction voltage when the scan electrode is selected or not selected is determined for each line according to the display pattern, this correction voltage is appropriately corrected according to the brightness adjustment voltage. As a result, the TV characteristics of cells that have become bright and cells that have become dark due to crosstalk are the same, and a high-quality display can be obtained even when the brightness adjustment voltage is changed.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. First, an example in which the method of the present invention is applied to the second crosstalk shown in FIG. 6 will be described.

FIG. 2 is a circuit diagram showing the configuration of an embodiment of a liquid crystal panel driving device embodying the present invention. In the figure, a data electrode driver (X driver) 21 is attached to the data electrode of the liquid crystal panel 23, and a scan electrode driver (X driver) is attached to the scan electrode of the liquid crystal panel 23.
Y driver) 22 are connected respectively. Reference numeral 24 denotes a power supply circuit, which divides the voltage between two potentials LC1 and GND using a plurality of resistors to generate voltages ①, .about.■. The voltages ■, ~■6 are the voltages necessary to implement the voltage averaging method explained in FIG. 10, and their values are v, =v v, = (2/a)VV2
=(1-1/a)V Vs =(1/a)V
Vs = (1-2/a)VV, = 0, where a is a number determined by the duty ratio.

Also, the potential V LCD is the power supply voltage ■. It is connected to a brightness adjustment volume 30 connected to. Therefore, the potential V L
The brightness of the CD is changed by adjusting the brightness adjustment volume 30.

The data electrode driver 21 is supplied with voltages v, , v, , v, , v from the power supply circuit 24, and the scan electrode driver 22 is supplied with a correction voltage adding circuit 2, which will be described later.
9 from the power supply circuit 24 through the voltages V,,V,,v,.

(2) Six potentials are given. A liquid crystal panel control device 26 is connected to the data electrode driver 21 and the scan electrode driver 22. The liquid crystal panel control device 26 sends X data, which is liquid crystal panel display data, to the data electrode driver 21 and the scan electrode driver 22 in response to a command from a control device such as a personal computer 25.
DATA and Y data YDATA, a data clock signal DCLK for synchronizing these data, and a signal signal for switching between the positive voltage application mode period and the negative voltage application mode period (hereinafter, the case of switching every frame will be described). ) is given as an example.

Further, the data electrode driver 21 and the scan electrode driver 22 receive X data XD from the liquid crystal panel control device 26.
ATA, Y data YDATA Nijin, and gave one of the data electrodes of each of the liquid crystal panel 23, and one of the above -mentioned voltage from the power supply circuit 24 in each scan electrode 24. That is, in the positive voltage application mode period, the data electrode driver 21 sets 0 to the data electrodes selected based on the X data XDATA, and sets (0) to the unselected data electrodes.
2/a) V is applied, and the scan electrode driver 22 is Y
Based on the data YDATA, V is applied to the selected scan electrode and (1/a) V is applied to the unselected scan electrode. Similarly, during the negative voltage application mode period, the data electrode driver 21 displays ■ for data electrodes selected based on the X data XDATA, and () for unselected data electrodes.
1-2/a) Apply V and scan electrode driver 22
is based on Y data YDATA, sets 0 to selected scan electrodes, and sets (1-1/a) to unselected scan electrodes.
) Apply V.

In this embodiment, in addition to the above configuration, a correction parameter generation circuit 27, a D/A conversion circuit 28, a correction voltage addition circuit 29, and a brightness adjustment voltage conversion circuit 31 are provided. The correction parameter generation circuit 27 includes a data latch circuit 271 that captures the X data XDATA in synchronization with the data clock signal DCLK, and a data detection circuit that detects 'ON' data from the output of the data latch circuit 271 and the data clock signal DCLK. 272, a counter 273 that receives the output of the data detection circuit 272 and calculates the number of "ON" data, and a latch 274. The initialization R5T of the counter 273 and the clock input CK of the latch 274 have a scan A scan synchronization signal 5SYNC for synchronizing electrode drive is connected, the count result is latched every scan drive period, and the counter 273 is reset and set to the initial state.

Further, the D/A conversion circuit 28 generates a correction voltage, and converts the digital count result output from the latch 2747 into a corresponding voltage value.

Further, the correction voltage addition circuit 29 includes an addition circuit 291 that adds the correction voltage to the scan electrode selection voltage (2) of the power supply circuit 24.
, an inversion circuit 292 that inverts the correction voltage, and a power supply circuit 2
The adder circuit 293 adds an inverted correction voltage to the scan electrode selection voltage (2) of No. 4 (6). The brightness adjustment voltage conversion circuit 31 includes a power supply 311 that generates a reference voltage Vf and a voltage adjustment volume 312.

Next, the operation of the circuit configured as above will be explained. The X data XDATA output from the liquid crystal panel control device 26 is sent to the data electrode driver 21, and at the same time is taken into the data latch circuit 271 therein by the correction parameter generation circuit 27 in synchronization with the data clock signal DCLK, and after latching. Output immediately. Then, in the data detection circuit 272, the data latch circuit 27
1 and the data clock signal DCLK, a pulse is output from the data detection circuit 272 only when the X data XDATA is "on".This output is input to the counter 273. The scan synchronization signal 5SYNC for synchronizing the scan electrode drive is input to the initialization manual R5T, and the counter 273 is reset every scan drive period.
The number of "on" states in ATA is counted by the number of rising or falling edges of the pulse output by data detection circuit 272, and the result is output from latch 274 as a correction parameter.

This correction parameter output is converted into a voltage by a subsequent D/A conversion circuit 28, which is a correction voltage generation circuit, and output as a correction voltage. This correction voltage is directly inputted to an addition circuit 291 in the correction voltage addition circuit 29, and the scan electrode selection voltage (2) is corrected. Further, this correction voltage is inverted and inputted to the addition circuit 293 through the inverting circuit 292, and the scan electrode selection voltage (2)6 is corrected in the opposite direction to the correction of the scan electrode selection voltage (1). This correction voltage becomes a larger value as the number of "'on"'s in the X data XDATA increases.

Then, when the brightness adjustment volume 30 is adjusted and the potential ■L0 of the power supply circuit 24 is changed, this potential VLC1
1 is input to the brightness adjustment voltage conversion circuit 31, and the power supply voltage of the D/A conversion circuit 28 is changed by the brightness adjustment voltage VLCD and the resistance of the adjustment volume 312 and the reference voltage Vf. Therefore, by changing the power supply voltage, the correction voltage is also changed in accordance with the adjustment of the brightness adjustment volume 30.

As a result, as shown in FIG. 4(a), the brightness adjustment voltage V
When the LCD is a low value (LCI, 2), the correction voltage Δ■ is a low value (ΔVZ), and when the brightness adjustment voltage VLCD is a high value (VLc++i), the correction voltage Δ■ is a high value (ΔV
become S). The corrected voltage Δ■ at this time is the following formula, ΔV=ΔV
m Xk (Vtco Vf). However, ΔV
m is the conventional correction voltage amount, k and Vf are coefficients. Therefore, appropriate correction is performed according to the brightness adjustment voltage VLCD, and the TV characteristics of cells where crosstalk has occurred and cells where no crosstalk has occurred match, and the brightness adjustment voltage VLCD
A high-quality display can be obtained even if the value is changed.

Next, an example in which the method of the present invention is applied to the second crosstalk shown in FIG. 6 will be described. FIG. 3 shows the configuration of a driving device for a liquid crystal panel embodying the present invention. Since the configuration of this driving device is almost the same as that of the driving device shown in FIG. 2, the same components are used. The same reference numerals are given to the same reference numerals, and the configuration will be explained only with respect to the parts that are different from the apparatus shown in FIG.

The device shown in FIG. 3 differs from the device shown in FIG. 2 in the configuration of the correction parameter generation circuit 27, and a down counter 275 is further added to the device shown in FIG.

The output of the data detection circuit 272 is input to the clock input CK of the down counter 275 and the counter 273.

Initializing down counter 275 manually RST and counter 2
The scan synchronization signal 5SYNC is input to the data load manual LOAD of 73, the value of the counter 273 is latched by the latch 274 every scan drive period, the calculation result of the down counter 275 is loaded to the counter 273, and the down counter 274 is Reset and latch 274
D/A converts the output. In addition, the correction voltage addition circuit 32
The configuration of the power supply circuit 24 is also different in the device shown in FIG.
A correction voltage is superimposed on the voltages 1 and 6 at , that is, the selection voltage of the scan electrode, but in this device, the correction voltage is superimposed on the voltages z and VS in the power supply circuit 24, that is, the non-selection voltage of the scan electrode. They are now superimposed.

Therefore, the correction voltage addition circuit 32 has D/
An addition circuit 321 that adds the outputs of the A conversion circuit 28, an inversion circuit 322 for the output of the D/A conversion circuit 28, and an addition circuit 323 that adds the output of the D/A conversion circuit 28 to the voltage (1). It is being

D/A conversion circuit 2 in the device configured as above
8 and the operation of the brightness adjustment voltage conversion circuit 31 are the same as those in the device shown in FIG.
At step 7, the difference in the number of "ON"s in the X data XDATA between one scan drive period and the next one scan drive period is counted, and the result is output as a correction parameter. Then, a correction voltage is created in the D/A conversion circuit 28 by this correction parameter output, and this correction voltage is directly input to the addition circuit 321 in the correction voltage addition circuit 32, and the scan electrode non-selection voltage 2 is corrected. is inverted and inputted to the adding circuit 323 through the inverting circuit 322, and the scan electrode non-selection voltage (2) is corrected.

Then, when the brightness adjustment volume 30 is adjusted and the potential ■Lo of the power supply circuit 24 is changed, this potential V LC
D is input to the brightness adjustment voltage conversion circuit 31, and the power supply voltage of the D/A conversion circuit 28 is changed by the brightness adjustment voltage VLCD and the resistance of the adjustment volume 312 and the reference voltage Vf. Therefore, by changing the power supply voltage, the correction voltage is also changed in accordance with the adjustment of the brightness adjustment volume 30.

As a result, as shown in FIG. 4(b), the brightness adjustment voltage V
When the LCD is at a low value (V Lcas), the correction voltage Δ■
is a low value (ΔVS), and when the brightness adjustment voltage VLcD is a high value (VLCD&), the correction voltage Δ■ is a high value (ΔVS).
V6). The corrected voltage Δ■ at this time is the following formula, ΔV=Δ
It is expressed as Vm Xk (VLco Vf). However, Δ
Vm is a conventional correction voltage amount, and k and Vf are coefficients. Therefore, appropriate correction is performed according to the brightness adjustment voltage V LCfl, and the T-characteristics of cells where crosstalk has occurred and cells where no crosstalk has occurred match, and the brightness adjustment voltage V
Good quality display can be obtained even if the LCD is changed.

Note that in the two embodiments described above, the brightness adjustment voltage conversion circuit 3
1 is configured with a power supply 311 that generates the reference voltage Vf and an adjustment volume 312, but the fluctuation of the brightness adjustment voltage is
/D conversion, determine the power supply voltage of the D/A conversion circuit 28 according to the brightness adjustment voltage using a conversion table in the digital value, and convert this to D/A as the power supply voltage of the D/A conversion circuit 28. is also good.

In addition, in the embodiment shown in FIG. 2, the correction voltage according to the data displayed on the selected scan electrode is applied every one scan electrode drive time, and the polarity is opposite between the positive voltage application mode period and the negative voltage application mode period. The present invention is applied to a driving method in which the voltage is added to the selected voltage of the scan electrode, and the embodiment shown in FIG. , the present invention is applied to a driving method in which the voltage is added to the non-selection voltage of the scan electrode. The driving method of the liquid crystal panel of the present invention is to apply the correction voltage to the data electrode selection voltage, the data electrode non-selection voltage, and the scan electrode non-selection voltage with opposite polarity during the positive voltage application mode period and the negative voltage application mode period. Driving method that adds to the voltage, ■ Adds to the selected voltage of the scan electrode with opposite polarity during the positive voltage application mode period and the negative voltage application mode period,
and a driving method in which the selection voltage of the data electrode, the non-selection voltage of the data electrode, and the non-selection voltage of the scan electrode are added with the opposite polarity to the selection voltage of the scan electrode, and ■ a positive voltage application mode period. This driving method can also be applied to a driving method in which the selection voltage of the data electrode and the non-selection voltage of the data electrode are added to each other with opposite polarity during the negative voltage application mode period.

FIG. 7 shows the configuration of the correction voltage addition circuit 70 and the connection with the D/A conversion circuit 28 when the present invention is applied to the driving method (2), where 71 to 76 are addition circuits, and 77 is an inversion circuit. It is. FIG. 8 shows the configuration of the correction voltage addition circuit 80 and the connection with the D/A conversion circuit 28 when the present invention is applied to the driving method (2), where 81 to 88 are addition circuits, and 89 is an inversion circuit. It is.

FIG. 9 shows the configuration of a correction voltage addition circuit 90 and its connection with the D/A conversion circuit 28 when the present invention is applied to the driving method (2), and 91 to 94 are addition circuits. Even in these configurations, depending on the magnitude of the brightness adjustment voltage,
The power supply of the D/A conversion circuit 28 is changed by a brightness adjustment voltage conversion circuit 31 (not shown), and the correction voltage is changed, but since the operation is exactly the same as the embodiment described above, no further explanation will be given.

In the above embodiments, it was assumed that the panel temperature was constant, but the panel temperature ranged from TloC to T2°c ('r.

〉T2), the optimum correction voltage straight line moves in parallel to the left as shown in FIG. This can be accommodated by changing the reference voltage Vf depending on the panel temperature.

The reference voltage Vf may be changed using a volume or automatically using a thermistor or the like.

Also, set the bias ratio a to the theoretical optimum value of 1 + 1 (however,
It may be combined with a method in which D is smaller than the duty ratio). This method is disclosed in Japanese Unexamined Patent Publication No. 59460124, and has the effect of improving the contrast ratio in addition to the effect of lowering the drive voltage described in the publication. However, when this method is used alone, there is a problem in that the drive margin becomes narrow, so that a slight change in effective voltage causes a large change in transmittance, making crosstalk more likely to occur. Therefore, by suppressing fluctuations in effective voltage due to display patterns in combination with the present invention, it is possible to solve the problem of cocoon talk, lower drive voltage, and improve contrast ratio.

In addition, in the above-mentioned example, v, -v v, = (2/a)VV
z = (1-1/a) V V s = (
1/a) VV:l = (1-2/a)VV
&=0, but in the voltage averaging method, it is sufficient that the difference between each voltage satisfies this relationship, so (1) to V6 may be increased or decreased by a certain voltage value.

In this embodiment, in order to set the drive voltage, the brightness adjustment voltage VLCD was used to obtain the optimal correction voltage.
A configuration using a voltage such as (1-2/a)v may also be used.

In addition, in the above embodiment, the explanation was given using a liquid crystal display device in which "r bright" display corresponds to "on" display data, but a liquid crystal display device in which "dark" display corresponds to "on" display data will be explained. , r 83 If the J display description is replaced with the "r dark" display and the r dark J display description is replaced with the "bright 1 display, it can be applied in exactly the same way.

〔Effect of the invention〕

As explained above, according to the present invention, in a simple matrix liquid crystal display device, the occurrence of brightness unevenness depending on the display pattern can be countered even by changing the brightness adjustment voltage, and a high-quality display can be obtained. There is.

[Brief explanation of drawings]

Fig. 1 is a basic configuration diagram explaining the detailed explanation of the present invention, Fig. 2 is a circuit diagram showing the structure of the first embodiment of the invention, and Fig. 3 is a diagram showing the structure of the second embodiment of the invention. The circuit diagram, FIG. 4(a), ■) is a characteristic diagram showing the effect of the embodiment shown in FIGS. 2 and 3, and FIG. 5 is a diagram explaining the conventional first crosstalk.
(a) is an example of display pattern, (b) is T- after conventional countermeasures
The V characteristic diagram, Figure 6, explains the conventional second crosstalk.
(a) is an example of display pattern, (b) is T- after conventional countermeasures
V characteristic diagram, Figures 7 to 9 are configuration diagrams of a brightness adjustment voltage conversion circuit explaining other embodiments of the present invention, Figure 10 is a correction characteristic diagram when the panel temperature changes, and Figure 11 is a diagram of 12 FIG. 12 is a diagram showing an example of a display pattern on a liquid crystal panel, and FIG. 13 is a diagram showing a voltage averaging method. 21... Data electrode driver, 22... Scan electrode driver, 23... Liquid crystal panel, 24... Power supply circuit, 26... Liquid crystal panel control device, 27... Correction parameter generation circuit, 28. ...D/A conversion circuit, 29, 32.70.80.90...Correction voltage addition circuit, 30...Brightness adjustment volume, 31...Brightness adjustment voltage conversion circuit, 271...Data latch circuit , 272...Data detection circuit, 273...Counter, 291, 293.321.323...Addition circuit, 27
2, 322... Inversion circuit, 312... Adjustment volume.

Claims (1)

[Scope of Claims] 1. A matrix type liquid crystal panel in which data electrodes and scan electrodes are provided in an intersecting manner is driven by a voltage averaging method having a positive voltage application mode period and a negative voltage application mode period, and one scan is performed. A driving method in which a correction voltage corresponding to the data displayed on the selected scan electrode is added to the selected voltage of the scan electrode at each electrode drive time, with polarity opposite between the positive voltage application mode period and the negative voltage application mode period. A method of driving a liquid crystal panel, characterized in that the correction voltage is changed according to the magnitude of a driving voltage of the liquid crystal panel. 2. A matrix-type liquid crystal panel in which data electrodes and scan electrodes are provided in an intersecting manner is driven by a voltage averaging method having a positive voltage application mode period and a negative voltage application mode period, and for each scan electrode driving time, The correction voltage according to the data displayed on the selected scan electrode is applied with opposite polarity during the positive voltage application mode period and the negative voltage application mode period, and the selection voltage of the data electrode, the non-selection voltage of the data electrode, and the A method for driving a liquid crystal panel, characterized in that the correction voltage is changed in accordance with the magnitude of the driving voltage for the liquid crystal panel, in the driving method for adding the voltage to a non-selected voltage. 3. A matrix-type liquid crystal panel in which data electrodes and scan electrodes are provided in an intersecting manner is driven by a voltage averaging method having a positive voltage application mode period and a negative voltage application mode period, and for each scan electrode driving time, A correction voltage corresponding to the data to be displayed on the selected scan electrode is added to the selected voltage of the scan electrode with opposite polarity during the positive voltage application mode period and the negative voltage application mode period, and the selected voltage of the scan electrode is In a driving method in which the selection voltage of the data electrode, the non-selection voltage of the data electrode, and the non-selection voltage of the scan electrode are added with the opposite polarity to the polarity when adding the correction voltage to the drive voltage of the liquid crystal panel. A method for driving a liquid crystal panel, which is characterized in that the method changes accordingly. 4. A matrix-type liquid crystal panel in which data electrodes and scan electrodes are provided in an intersecting manner is driven by a voltage averaging method having a positive voltage application mode period and a negative voltage application mode period, and for each scan electrode driving time, In a driving method in which a correction voltage corresponding to the data displayed on the selected scan electrode is added to the non-selected voltage of the scan electrode with opposite polarity during the positive voltage application mode period and the negative voltage application mode period, the correction voltage is A method for driving a liquid crystal panel, characterized in that the voltage is changed according to the magnitude of a driving voltage for the liquid crystal panel. 5. A matrix-type liquid crystal panel in which data electrodes and scan electrodes are provided in an intersecting manner is driven by a voltage averaging method having a positive voltage application mode period and a negative voltage application mode period, and for each scan electrode driving time, A correction voltage according to the data to be displayed on the selected scan electrode is added to the selected voltage of the data electrode and the non-selected voltage of the data electrode, with polarity opposite in the positive voltage application mode period and the negative voltage application mode period. A method for driving a liquid crystal panel, characterized in that the correction voltage is changed according to the magnitude of a driving voltage for the liquid crystal panel.