JP2002196727A - Method for driving liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate white stripes appearing on the border between two pictures to obtain high quality display. SOLUTION: A scanning start signal FRM, a scanning clock LP, and a display signal DISP for controlling a top and bottom two-split simple matrix type liquid crystal display device are inputted to a counter circuit; a CDISP is outputted which controls the bottom picture scanning electrode driving circuit to a non selection voltage VM according to the count result of the FRM and a scanning clock CP when DISP is ON; selection voltages VH, VL, and VM are inputted to a top and bottom picture scanning electrode driving circuit, and voltage V0 and V1 corresponding to ON/OFF of display data and VM are inputted to a top and bottom picture signal electrode driving circuit; and, by the display signal CDISP the bottom picture scanning electrode driving circuit outputted by the counter circuit, VM is applied from a driving power source circuit only to the bottom picture scanning electrodes to be selected first during one frame period for a prescribed period shorter than a one-line scanning period when a driving duty ratio for one frame period is 1/(n+α) to the number of scanning electrodes (n) of each top and bottom picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for driving a liquid crystal display.

[0002]

2. Description of the Related Art P. FIG. 6 shows a configuration example of a simple matrix type liquid crystal display device of a two-screen division system driven by an (Alt Pleshko) method.

According to FIG. 1, a scanning substrate in which scanning electrode patterns and alignment films arranged in one direction are sequentially laminated,
A signal electrode pattern and a signal side substrate on which an alignment film is sequentially laminated are arranged in the other direction, and a signal side substrate on which an alignment film is sequentially laminated is disposed opposite to each other via a liquid crystal layer, and both electrode patterns are crossed to form a square shape. An upper / lower two-screen split type liquid crystal panel 1 having no display area and a total of 2n scanning electrodes, and an upper screen scanning electrode driving circuit 2 for driving upper screen scanning electrodes
A lower screen scanning electrode driving circuit 3 for driving a lower screen scanning electrode; an upper screen signal electrode driving circuit 4 for driving an upper screen signal electrode; and a lower screen signal electrode driving circuit for driving a lower screen signal electrode. 5 and a driving power supply circuit 6 for generating a predetermined voltage for driving the liquid crystal panel 1.

A control signal such as a scan start signal FRM, a scan clock LP and a data latch pulse LP, an AC signal DF, a data shift clock CP, display data, and a display signal DISP are supplied from outside.

The driving power supply circuit 6 includes the scanning electrode driving circuit 3
Select voltage VH, VL of scan electrode and non-select voltage VM
The signal electrode drive circuits 4 and 5 turn on the display of the signal electrodes.
V0, V1, and an intermediate voltage VM corresponding to / OFF. The non-selection voltage VM and the intermediate voltage VM are the same voltage.

Next, the operation of the drive circuit when a display as shown in FIG. 6 is made on the liquid crystal display device will be described with reference to FIGS. 7 and 8. FIG. 7 shows the timing of the control signal, and FIG. 8 shows an ideal waveform of the operation.

After the input of the rising edge of the scanning start signal FRM,
The scan electrode drive circuits 3 of the upper and lower screens apply a selection voltage to the first scan electrodes X1 and X1 'of each screen in synchronization with the fall of the first scan clock (this is referred to as "selection"). The selection voltage is either the voltage VH or the voltage VL according to the AC signal DF.

At the same time, the signal electrode driving circuit Y1 responds to the contents of the display data taken in and the AC signal DF.
One of the voltages V0 and V1 is output to all the electrodes Ym to Ym, and at the same time, the next display data is captured in synchronization with the data shift clock CP.

The outputs of the scan electrode drive circuit and the signal electrode drive circuit are maintained until the next scan clock LP falls, and when the next scan clock is input, the scan electrodes X2 and X2 'are output. Is selected, and the signal electrode driving circuit selects Y in accordance with the content of the display data taken in.
One of the voltages V0 and V1 is output to all the electrodes 1 to Ym, and then X3 and X3 ',... Xi and Xi' are sequentially selected. The non-selection voltage VM is applied to the other scanning electrodes that are not selected.

Then, when the scan start signal FRM is inputted after the last scan electrodes Xn and Xn 'of each screen are selected, the scan electrodes are sequentially selected again from the top scan electrode of each screen. Repeat the operation. A period from the input of the scan start signal FRM to the input of the next scan start signal FRM is referred to as a frame period.

When the display signal DISP is not input, the outputs of the scan electrode drive circuit and the signal electrode drive circuit are forcibly fixed to the voltage VM, but the other scan electrode drive circuits and the signal electrode drive circuits are not. The internal operation is the display signal DIS
This is performed regardless of the presence or absence of P.

[0012] From the above operation, the ideal waveform at the time of driving the circuit operation when the pixels on the Yj line is performing a display by the black circle and the white circle as shown in FIG. 6 is as shown in FIG.

[0013]

However, since the liquid crystal panel 1 is equivalently represented by an RC distributed constant circuit composed of an ITO electrode and a liquid crystal capacitor, an actual driving waveform has distortion or dullness. .

In recent years, there has been proposed a simple matrix type liquid crystal display device in which a semi-transmissive film is provided inside a liquid crystal panel so that the device can be used under both sunlight and a dark place. In many cases, a dielectric material or the like is used for the semi-permeable film as a material of the film, and the use of such a semi-permeable film also causes distortion or dullness in the drive waveform.

Hereinafter, this problem will be described in detail. First, a liquid crystal panel provided with a semi-transmissive film will be described with reference to FIG. FIG. 1 is a cross-sectional view of a transflective color type liquid crystal panel.

The scanning-side substrate 8 and the signal-side substrate 9 are bonded together with a seal portion 10, and a liquid crystal layer 11 is sealed in a region surrounded by the seal portion 10.

The seal portion 10 is made of epoxy, acrylic,
Such a structure is made of a thermosetting resin such as a silicone resin. In such a structure, the scanning side substrate 8 and the signal side substrate 9 are adhered to each other via a sealant, and a space is provided by further aligning the sealant. Then, the sealing portion 10 is formed by curing.

When this space is provided, non-conductive spacers 12 made of resinous spheres are dispersed and dispersed between the scanning-side substrate 8 and the signal-side substrate 9 so that the distance between the two substrates is kept constant. The liquid crystal layer 11 is sealed in the substrate.

A plurality of signal electrodes 13 are arranged in parallel on the signal substrate 9, and the arrangement pattern is the seal portion 1.
It extends out of zero.

A semi-transmissive film 21 is formed on the other scanning-side substrate 8, and is made of, for example, a dielectric having a thickness of about 1 μm. A color filter 14 and an overcoat 15 are sequentially formed thereon, and a plurality of scanning electrodes 16 are further formed thereon.
Are arranged in parallel, and the arrangement pattern extends to the outside of the seal portion 10.

The color filter 14 is coated with a color resin solution of each color in which red (R), green (G), and blue (B) coloring materials such as dyes and pigments are uniformly dispersed on a transparent resin or the like. Is formed by a dispersion method or the like in which patterning is performed.

The overcoat 15 is a color filter 1
4 to protect the colorant 4 and prevent the coloring material from being eluted into the liquid crystal layer 11, and is made of a transparent resin.

When the signal substrate 9 and the scanning substrate 8 are bonded to each other, the signal electrodes 13 and the scanning electrodes 16 are arranged so as to be orthogonal to each other, and a region where these electrodes intersect is a rectangular display region.

The signal electrode 13 and the scanning electrode 16 are made of ITO.
(Indium Tin Oxide). Then, an alignment film 17 of a polyimide resin is coated on the signal electrodes 13 and the scanning electrodes 16.

The signal electrode 1 extending outside the seal portion 10
A signal electrode drive circuit and a scan electrode drive circuit are connected to the scan electrodes 3 and the scan electrodes 16, respectively, and the liquid crystal panel is driven through these circuits.

A retardation plate 18 and a polarizing plate 19 for optical compensation are arranged outside the scanning substrate 16 and the signal substrate 9, respectively. Further, a backlight system 20 is provided on the scanning side substrate side of the liquid crystal panel. Are arranged, and ON (ON) and OFF (OFF) of pixels in the display area
As a result, light from the backlight system 20 is passed or blocked, and a display state is established.

In the above transflective liquid crystal panel,
A reduction in visibility of a transmissive panel under strong light such as sunlight can be eliminated by reflecting sunlight with a semi-transmissive film. On the other hand, the display can be performed by turning on the backlight system 20 even in a dark place.

However, the line-to-line capacitance between the scanning electrodes of the liquid crystal panel is increased by the dielectric material used for the semi-transmissive film 21. When the liquid crystal display device is driven, each electrode rises and falls in the voltage applied to the adjacent electrode. , And the waveform actually becomes a waveform at the time of operation of the drive circuit as shown in FIG.

That is, noise accompanying the rising of the selection voltage of the scanning electrode Xi selected immediately before the scanning electrode Xi + 1 itself is selected is applied to the scanning electrode Xi + 1. Although only the noise accompanying the rise of the selection voltage is shown in the figure, the noise associated with the fall is actually applied in the opposite direction to the voltage of the noise associated with the rise, and accordingly, the scan electrode Xi + 1 itself is correspondingly applied. Had risen up.

More specifically, when driving the liquid crystal display device, the number of scanning electrodes and the driving duty ratio of one screen are usually the same, and if the number of scanning electrodes is n, the driving duty ratio is 1 / n. It is. For example, in the case of an 800 × 600 dot two-screen split type liquid crystal display device, the number of scanning electrodes in one screen out of two screens is 300, and the driving duty ratio is 1/300. In the control signal, there are 300 scan clocks LP in one frame period.

However, in an electronic device equipped with a liquid crystal display device, not only the liquid crystal display device, but also a CRT may be displayed at the same time, or the liquid crystal display device and the CRT may be switched and displayed. Often, the circuits are capable of operating both the liquid crystal display and the CRT. Therefore, the scanning start signal FRM of the control signal and the scanning clock LP are shown in FIG.
As shown in FIG. 1, the same number of scan clocks LP do not exist each time within one frame period, and n pulses and n + α pulses alternate (α is a positive integer, n is the number n of scan electrodes for one screen in FIG. 6).
And the same).

This is called a simultaneous scan,
This is a technique used when simultaneously operating the RT and the liquid crystal display device.

For example, when n = 300 and n + α = 302, the drive duty ratios are 1/300 and 1/300.
302 alternates. In a frame period in which the scan clock LP has 302 pulses, from the first scan electrode to the 300th scan electrode in order from 1 to 300 pulses, the 301st and 302th scan electrodes are selected at the 301st and 302nd pulses. Does not exist, all lines are not selected during this period.

In some cases, there are n + α pulses of the scanning clock every time. In this case, the driving duty becomes 1/302.

However, when the liquid crystal panel is operated by the above-described simultaneous scan or the like, there are the following problems. This problem will be described with reference to FIGS. 12A and 12B when the selection voltage is VH.

As shown in FIG. 12A, during the period in which n scan clocks LP exist, after the scan electrode Xn selected last in the upper screen of one frame period is selected,
The scan electrode X which is the scan start electrode of the lower screen immediately next to it
1 'is selected, so that all scan electrodes are selected immediately after adjacent scan electrodes are selected, and all scan electrodes receive noise interference from adjacent scan electrodes, but have the same size. There is no impact.

However, during the period in which the n + α pulse scan clock is present, the scan electrode X1 'is not selected immediately after the scan electrode Xn is selected.
Reference numeral 1 'denotes noise interference received from an adjacent scanning electrode (= scanning electrode Xn) as compared with the other scanning electrodes, and in particular, noise interference caused by the falling of the selection voltage is caused by the rising of the selection voltage as shown in FIG. Since they do not overlap, the rise of the selection voltage becomes steeper than during the period in which the n-panel scan clock exists.
Therefore, a voltage higher than the pixels on the other scan electrodes is applied to the pixels on the scan electrode X1 ', and the pixels on the scan electrode X1' are lit whiter than the surroundings and appear as white stripes. Was.

Further, when the scan clock has n + α pulses each time, the scan electrode Xn of the scan electrode X1 '
Since the noise interference received from each line is different from that of the other lines during each frame period, the pixels on the scan electrode X1 'were lit whiter than the surroundings, and looked like white stripes.

Accordingly, the present invention has been completed in view of the above description, and an object of the present invention is to provide a simple matrix type liquid crystal display device of a two-screen split type in which a white-line streak generated at a boundary between two screens is eliminated. An object of the present invention is to provide a method for driving the device.

[0040]

According to the present invention, there is provided a method of driving a liquid crystal display device, comprising: a scanning side substrate on which scanning electrode patterns and alignment films arranged in one direction are sequentially laminated; and a signal arranged in the other direction. A signal side substrate on which an electrode pattern and an alignment film are sequentially laminated is arranged to face each other via a liquid crystal layer, and both electrode patterns intersect to form a rectangular display area.
A liquid crystal panel of a two-screen division type in which the signal electrode pattern is divided into two and the number of scanning electrodes is 2n; a one-screen scanning electrode driving circuit for driving one screen of the scanning electrodes; The other screen scanning electrode driving circuit, the one screen signal electrode driving circuit driving one screen of the signal electrodes, the other screen scanning electrode driving circuit driving the other screen, and the liquid crystal panel. A liquid crystal display device having a driving power supply circuit for generating a predetermined voltage of:
When performing the duty drive whose drive duty is 1 / (n + α), the first screen period immediately after performing the 1 / (n + α) duty drive is selected at the beginning of the scanning electrode selection period of the other screen. First, a non-selected voltage is applied for a predetermined period shorter than the selection period of one line.

Another driving method of the liquid crystal display device of the present invention is as follows.
In the liquid crystal display device, the drive duty is 1 / (n + α) with respect to the number n of scan electrodes on one screen out of two screens.
When the duty driving is performed, at the end of the scanning electrode selection period of the other screen, which is selected at the beginning of the frame period immediately after performing the 1 / (n + α) duty driving,
A non-selected voltage is applied only for a predetermined period shorter than the selection period of one line.

According to the driving method of the liquid crystal display device of the present invention, 2
When the drive duty is 1 / (n + α) with respect to the number n of the scanning electrodes of one screen in the screen, at the beginning of the frame period immediately after the 1 / (n + α) duty drive is performed. At the beginning of the selection period of the scanning electrode of the other screen to be selected, the non-selection voltage is applied only for a predetermined period shorter than the selection period of one line, that is, the number of scanning electrodes n of one screen Applying the non-selection voltage VM only for a predetermined period shorter than the selected period to only the first selected scanning electrode in one frame period when driving is performed with a duty divided by a larger number. Thus, the applied voltage of the pixel on the scan electrode X1 'can be reduced by the increased amount, so that the pixel on the scan electrode X1' performs the same display as the surrounding pixels, and as a result, it occurs at the boundary between two screens. white line The streaks can be eliminated.

According to another driving method of the liquid crystal display device of the present invention, when the duty driving in which the driving duty is 1 / (n + α) is performed with respect to the number n of the scanning electrodes of one screen out of two screens. , 1 / (n + α), at the end of the selection period of the scanning electrode of the other screen, which is selected at the beginning of the frame period immediately after the duty driving of the other screen, is performed for a predetermined period shorter than the selection period of one line. By applying the voltage, that is, only the timing of applying the non-selection voltage during the selection period is different from that described above, the application voltage of the pixel on the scan electrode X1 'is similarly reduced by the increment. As a result, the pixels on the scanning electrode X1 'are displayed in the same manner as the surrounding pixels, and as a result, white stripes generated at the boundary between the two screens can be eliminated.

[0043]

Embodiments of the present invention will be described below with reference to the drawings. (Example 1) FIG. 1 is a view schematically showing a liquid crystal display device according to the present invention. The same parts as those of the conventional liquid crystal display device shown in FIG.

A scanning substrate in which scanning electrode patterns and orientation films arranged in one direction are sequentially laminated, and a signal electrode pattern and orientation film arranged in the other direction and divided at the center thereof are sequentially laminated. The signal-side substrate is disposed to face with the liquid crystal layer interposed therebetween, and both electrode patterns intersect to form a rectangular display area.

The liquid crystal panel 1 is a two-screen split type liquid crystal panel having a total of 2n scanning electrodes, and the one-screen scanning electrode driving circuit for driving the scanning electrodes of the upper screen which is the one screen among the scanning electrodes. An upper screen scan electrode drive circuit 2 and a lower screen scan electrode drive circuit 3 as the other screen scan electrode drive circuit for driving the lower screen scan electrode as the other screen
And an upper screen signal electrode drive circuit 4 which is the one screen signal electrode drive circuit for driving the upper screen signal electrode among the signal electrodes, and a lower which is the other screen signal electrode drive circuit which drives the lower screen signal electrode. A screen signal electrode drive circuit 5, a drive power supply circuit 6 for generating a predetermined voltage for driving the liquid crystal panel 1, a scan start signal FRM and a scan clock LP are counted, and a display signal CDISP is output according to the result. And a counting circuit 7.

The control signals such as the scan start signal FRM, the scan clock LP and the data latch pulse LP, the AC signal DF, the data shift clock CP, the display data, and the display signal DISP are supplied from outside.

The upper screen scan electrode drive circuit 2 and the lower screen scan electrode drive circuit 3 receive a scan start signal FRM, a scan clock LP and an alternating signal DF, and the upper screen scan electrode drive circuit 2 displays signals. DISP and a display signal CDISP, which is an output of a count circuit described later, are input to the lower screen scan electrode drive circuit 3.

Display data, data shift clock CP, data latch pulse LP (same as scan clock) and display signal DISP are input to upper screen signal electrode drive circuit 4 and lower screen signal electrode drive circuit 5.

The display signals DISP and CDISP are signals for controlling the scanning electrode driving circuit and the signal electrode driving circuit to which the respective signals are inputted to the voltage VM.

The count circuit 7 counts the scan start signal FRM and the scan clock, and if the display signal DISP is ON, outputs the display signal CDISP of the lower screen scan electrode drive circuit 3 according to the count result.

Next, the operation of the drive circuit when the display is performed by black circles and white circles as shown in FIG. 1 is shown in FIG.
FIG. FIG. 2 shows the timing of the control signal, and FIG. 3 shows the actual operation waveform.

After the pulse of the scanning start signal FRM is input, the counting circuit 7 counts the number of pulses of the scanning clock LP within the frame period. Then, the number of scan clocks LP counted in the frame period is 1
Display signal C to be output when the number is equal to the number of scanning electrodes on the screen
DISP keeps ON. On the other hand, when the number of scan clocks LP counted in one frame period is larger than the number of scan electrodes in one screen, the display signal CDIS is output immediately after counting the first scan clock LP in the next frame period.
P is turned off for a predetermined period. These are illustrated in FIG.

When the display signal DISP is OFF, the display signal CDISP is OFF in any case.

With the above operation, the drive waveform of the lower screen scan electrode drive circuit 3 is the same as the conventional one as shown in FIG. 3A when the scan clock LP is the same as the number of scan electrodes in one screen. However, when the number of scan clocks LP is larger than the number of scan electrodes, as shown in FIG. 3B, only the uppermost scan electrode on the lower screen has a non-selection voltage VM for a predetermined period during the selection period. There is output.

For example, the aforementioned 800 × 600 dots 2
In the case of a screen division type liquid crystal display device, the display signal CDISP is not turned off immediately after a period in which there are 300 scan clocks in one frame period. In many cases, only the top scanning electrode of the lower screen selected at the beginning of the next frame period of the frame period is turned off by the display signal CDISP for a predetermined period during the selection period, so that the non-selection voltage is reduced. Is output.

The OFF period of the display signal CDISP is determined each time by the liquid crystal display device. More specifically, the pixels on the scanning electrode X1 'may be displayed in the same manner as the surrounding pixels.

Thus, in the liquid crystal display device of the present invention, the pixel on the scanning electrode X1 'is displayed in the same manner as the surrounding pixels by such an operation, and the white line streak which has occurred at the boundary between the two screens as in the prior art is eliminated. Thus, the boundary between the upper screen and the lower screen disappeared, and a high-quality display could be obtained.

(Example 2) Next, another driving method of the present invention will be described. Note that, also in this example, description will be made using the liquid crystal display device shown in FIG.

FIG. 4 is a control signal diagram thereof, and FIG. 5 is a waveform diagram thereof. In this example, the point that the display signal CDISP of the lower screen scan electrode driving circuit is output by counting the scan start signal FRM and the scan clock LP is the same as that in (Example 1). X
Instead of having been at the beginning of the selection period 1 ', it is at the end. Otherwise, as in (Example 1), the pixels on the scanning electrode X1 'have the same display as the surrounding pixels, and as a result, a high-quality display without a boundary between the upper screen and the lower screen can be obtained.

(Preferred Example 1) As described above, in the simple-matrix liquid crystal display device of the two-screen split system, the driving method of the present invention can eliminate the white-line streaks generated at the boundary between the two screens. This has a remarkable effect in a liquid crystal panel provided with a semi-transmissive film using a dielectric or the like in which distortion or rounding is likely to occur.

The configuration of the liquid crystal panel provided with the semi-transmissive film of this embodiment is the same as that shown in FIG.

(Preferred Example 2) As described above, in an electronic device equipped with a liquid crystal display device, not only the liquid crystal display device but also a CRT can be displayed at the same time, or the liquid crystal display device and the CRT can be switched and displayed. Therefore, the control circuit is configured to operate both the liquid crystal display device and the CRT, and the simultaneous scan technology is used for this configuration. The white line-shaped streaks generated at the border of the line were most effectively eliminated.

The present invention is not limited to the above embodiment, and various changes and improvements may be made without departing from the scope of the present invention. For example, in the above-described embodiment, the liquid crystal panel is a two-screen upper and lower screen, but may be a two-screen left and right screen instead.

[0064]

As described above, according to the driving method of the liquid crystal display device of the present invention, in the simple matrix type liquid crystal display device of the two-screen division system, the number of scanning electrodes n of one screen out of two screens is increased. At the beginning of the scanning electrode selection period of the other screen, which is selected at the beginning of the frame period immediately after the 1 / (n + α) duty driving is performed when the driving duty is 1 / (n + α). The non-selection voltage is applied only for a predetermined period shorter than the selection period of one line, or 1 / (n + α)
By applying a non-selection voltage for a predetermined period shorter than the selection period of one line, at the end of the selection period of the scanning electrode of the other screen, which is selected at the beginning of the frame period immediately after performing the duty drive of (2) White line-like streaks generated at the boundary between two screens can be eliminated, and a high-quality liquid crystal display device can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a liquid crystal display device according to the present invention.

FIG. 2 is a diagram showing the timing of a control signal in the driving method of the present invention.

FIG. 3 is a diagram showing actual waveforms when a scan electrode drive circuit is driven by the drive method of the present invention.

FIG. 4 is a diagram showing the timing of a control signal in the driving method of the present invention.

FIG. 5 is a diagram showing actual waveforms when a scan electrode drive circuit is driven by the drive method of the present invention.

FIG. 6 is an explanatory view schematically showing a conventional liquid crystal display device.

FIG. 7 is a diagram showing the timing of a control signal in a conventional driving method.

FIG. 8 is a diagram showing an ideal waveform when a scan electrode driving circuit is driven by a conventional driving method.

FIG. 9 is a diagram showing actual waveforms when a scan electrode drive circuit is driven by a conventional drive method.

FIG. 10 is a schematic sectional view showing the structure of a transflective color liquid crystal panel.

FIG. 11 is an explanatory diagram of a waveform related to a simultaneous scan.

FIG. 12 is a diagram showing driving waveforms during simultaneous scanning.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 2 screen division | segmentation type liquid crystal panel 2 ... Upper screen scan electrode drive circuit 3 ... Lower screen scan electrode drive circuit 4 ... Upper screen signal electrode drive circuit 5 ... Lower screen scan electrode drive circuit 6 ... Drive power supply circuit 7 ... Count circuit Reference Signs List 8 scanning side substrate 9 signal side substrate 10 sealing portion 11 liquid crystal layer 12 spacer 13 signal electrode 14 color filter 15 overcoat 16 scanning electrode 17 alignment film 18 retardation plate 19 polarizing plate 20: backlight system 21: semi-permeable membrane

Continued on the front page F term (reference) 2H093 NA07 NB03 NC03 NC16 NC27 ND01 ND09 ND34 NE06 5C006 AC21 AC22 AC24 AF71 BB12 BC03 BF22 5C080 AA10 BB06 DD02 DD30 FF12 JJ02 JJ04 JJ06

Claims (2)

[Claims] 1. A scanning-side substrate in which scanning electrode patterns and orientation films arranged in one direction are sequentially laminated, and a signal-side substrate in which signal electrode patterns and orientation films arranged in another direction are sequentially laminated. Are arranged facing each other with a liquid crystal layer interposed therebetween to form a rectangular display area by intersecting both electrode patterns.
A liquid crystal panel of a two-screen division type in which the signal electrode pattern is divided into two and the number of scanning electrodes is 2n; a one-screen scanning electrode driving circuit for driving one screen of the scanning electrodes; The other screen scanning electrode driving circuit, the one screen signal electrode driving circuit driving one screen of the signal electrodes, the other screen scanning electrode driving circuit driving the other screen, and the liquid crystal panel. A liquid crystal display device having a drive power supply circuit for generating a predetermined voltage of:
When performing the duty drive whose drive duty is 1 / (n + α), the first screen period is selected immediately after the 1 / (n + α) duty drive is performed. First, a non-selection voltage is applied only for a predetermined period shorter than the selection period of one line, and a driving method of the liquid crystal display device. 2. The liquid crystal display device according to claim 1, wherein the duty ratio is 1 / (n + α) when the driving duty is 1 / (n + α) with respect to the scanning electrode number n of one screen out of two screens. At the end of the selection period of the scan electrode on the other screen, which is selected at the beginning of the frame period immediately after the duty drive of / (n + α) is performed, the voltage at the time of non-selection is reduced for a predetermined period shorter than the selection period of one line. A method for driving a liquid crystal display device, comprising applying a voltage.