JPH02177679A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To form a picture display device in which the display performance of liquid crystal is sufficiently used by inverting a phase in units of either picture elements or scanning lines in the cycle of one frame. CONSTITUTION:A liquid crystal display device is equipped with a picture display signal generating means to invert the polarity of a picture element display signal synchronously with the field cycle of a picture display signal and supply the polarity inverted picture display signal to a picture element electrode. Further, the device is equipped with a common signal generating means to generate two level voltage to be inverted synchronously with the field cycle and supply the two level voltage to be inverted to a common electrode as a common electrode signal. A common electrode potential is changed into 9-6(a) and 9-6(b) and set for a waveform 9-1 and a waveform 9-2 respectively. Namely, the common electrode potential is alternated between 9-6(a) and 9-6(b) in the polarity inverting cycle of a signal to drive the liquid crystal. Thus, satisfactory display can be obtained.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is directed to ma! -Relates to a single image display device such as a television using a liquid crystal display panel.

[Conventional technology]

Various display devices were devised using the electro-optic effect of liquid crystals.
Or it has been put into practical use. These are due to the combination of alignment characteristics of liquid crystal molecules, dielectric anisotropy, optical anisotropy, etc.
- DSM as an internal common name.

There are names such as TN, GH, etc. Common features of these liquid crystals include that they have a light-receiving display effect, that they have relatively high resistance, and that the threshold value of the display characteristics is slow or unstable with respect to each parameter. The fact that it is a light-receiving type and has high resistance is why liquid crystals are superior to other display elements and are put into practical use as display elements; however, on the other hand, their threshold characteristics are inferior to other display elements. This makes the driving conditions for liquid crystals complicated and difficult. Furthermore, the short lifespan compared to DC drive is another factor that makes the drive conditions difficult.

FIG. 1 is a circuit diagram around a display panel showing a conventional embodiment, for example, in the document S ID77D IGESTP64-6.
Examples can be seen in 5th grade. In the figure, 2-1 is an image signal input such as a TV video signal, 2-2 is a synchronization separation signal, and 2-3
is a circuit that generates a control signal such as a timing clock from a synchronous separation signal.

2-4.2-5 is a circuit that controls the vertical lines or groove lines of the 7-trix display section and distributes and scans display signals to each matrix pixel. 2-4 is a drain drive circuit that converts the serial image signal manually input from 2-1 into parallel and supplies it to the drain side of the transistor connected in series to each pixel. 2-5 is 2
-3 The gates of the transistors connected in series to each pixel are sequentially turned ON and OFF for each line using the output clock.
This is a gate drive circuit that reads image signals into pixels.

The output side drains 2-6 of the transistors arranged in each matrix section are coupled to each pixel electrode of the liquid crystal display. As stated in Document S ID78DIGEST P96-97 (in the conventional 7-trix display using the circuit shown in Fig. 1, the liquid crystal drive was a direct current drive. In Fig. 1, the liquid crystal Contents of the electrodes sandwiching the liquid crystal of the matrix display body The electrodes facing the pixel N11i are as follows:
It consists of a common electrode over the entire display surface, and the potential is set at the GND level and matches the common side electrode potential of the substrate of the MOS transistor and the capacitors arranged in parallel. For this reason, liquid crystal materials require treatments such as doping with redox agents in order to maintain a long DC life.

Here, the relationship between the signal waveform and potential in the circuit of FIG. 1 is shown in FIG. Reference numeral 3-1 is an image signal supplied to the terminal 2-1, and reference numeral 3-2 is a synchronization signal when the image signal is sampled for each seven-trix data line in the block 2-4. The horizontal axis t represents time, and the vertical axis V represents voltage. 3-3 represents the black level of the image signal, 3-4 represents the white level, and the liquid crystal threshold 1ii! Corresponds to voltage and saturation voltage, respectively. Voltage 0 corresponds to GND in FIG. 1, and the substrate and common voltage If! There is only one electric line.

Furthermore, another example of a conventional circuit related to the present invention is shown in FIG. Specifically, examples can be found in S ID78DIGESTP94-95, etc. In Figure 3, 4-1 is Figure 1 2-1
Corresponds to the image signal human power. 4-2 is a low-pass filter, 4-3 is an amplifier, 4-4 is an A/D converter, 4-
5 is a data encoder, and 4-8 is a serial/parallel conversion shift register. The image signal 4-1 is converted into an image signal of a band corresponding to the display performance of the display panel through a low-pass filter and an amplifier, and then converted into a digital code by an A/D converter. 4-8 outputs the converted image digital image data to each data line of the matrix in parallel. Parallel output data is provided by D/A for each data line.
The signal is input to a converter and converted back into an analog image signal. At this time, the gain of the D/A converter output signal is controlled by the gain control circuit 4.
-9, and is adjusted so that the (1r1 pressure-contrast) correlation characteristic of the liquid crystal matches the contrast of the image signal. Furthermore, the D/A output is a buffer amplifier 4-12.
is input. 4-12 is the offset bias level,
'1. ! The adjustment circuit 4-10 adjusts the reference level of the image signal so that it corresponds to the vicinity of the threshold value of the liquid crystal, and outputs the image signal to the data line. 4-6 is a synchronization separation circuit, 4-7 is a timing signal generation circuit, and 4-13 is a circuit for controlling the clock line of the 7-trix display section, which corresponds to 2-5. 4-1
Reference numeral 6 denotes a display matrix section, whose configuration is the same as 2-7 in FIG. 1, so the illustration is omitted. In the circuit example shown in FIG. 3 as well, the liquid crystal is driven by direct current, as in FIG. 1. Further, in FIG. 3, there is a gain control circuit 4-9 and an offset bias level control circuit 4-10 for the image signal supplied to the data line of the matrix display section, which adjusts the signal level according to the characteristics of the liquid crystal display. It allows for adaptation.

[Problems with the Prior Art] In the conventional circuit as described above, a D/A converter that adjusts the gain and a buffer amplifier that adjusts the offset are provided for each data line, and each is connected to the same control signal line. It is adjusted by Therefore, as is clear from FIG. 3, the number of D/A converters and buffer amplifiers equal to the number of data lines is required, making the data line driving circuit extremely complicated.

Furthermore, each D/A or amplifier constituting the buffer is
Gain and other amplification characteristics must match.

It is nearly impossible to match the characteristics of each amplifier without adjustment in terms of element manufacturing, so adjustment must be made for each amplifier in advance.

[Purpose of the invention]

The present invention aims to improve the conventional drawbacks and provide an image display device that fully utilizes the display performance of liquid crystal.

According to the invention, the document Dlspray conf, 1
Even if the number of matrix scanning lines is greatly increased compared to the so-called dynamic drive method of 976P51, the display contrast performance of the liquid crystal will not be impaired in the slightest, and the applied voltage required for display drive will not increase. Furthermore, screen flickering (so-called flicker) does not occur.

Furthermore, since the present invention drives the liquid crystal with alternating current, it is possible to maintain the life of the liquid crystal for a long time, and there is no need to mix additives such as redox agents. The circuit implementing the present invention is greatly simplified compared to the one shown in FIG. There are no factors that cause such variations.

〔Example〕

FIG. 4 is a block diagram showing an overall view of a television receiver constructed using the liquid crystal image display device according to the present invention. In the figure, 5-1 is a part of a tuner that selects the frequency of a predetermined channel from received radio waves input from an antenna. 5-2 is a circuit from the intermediate frequency amplifier to image detection, 5-4 is a circuit for audio intermediate frequency, detection, output, etc., and 5-5 is a circuit for separating horizontal, vertical, etc. synchronization signals from the video signal. It is. Reference numeral 5-3 denotes a video amplification circuit block according to the present invention, which outputs a liquid crystal display image signal to a subsequent stage matrix display section data signal latch circuit 5-8. 5-9 is a data line driving circuit. 5-6. 5-7 receives the output of the synchronization signal separation circuit 5-5, and sends a data latch signal to 5-8, and a timing signal for driving the matrix display clock line (horizontal line) to 5-10. % pay. 5-
Reference numeral 11 denotes a power source, which supplies a common electrode voltage to be described later to the common electrode 5-13 (-dotted chain line). 5-12 represents a matrix type liquid crystal display panel, the details of which are shown in FIG. 6-1 is a gate drive circuit, and 6-2 is a drain drive circuit, each of which is provided with a transistor for selectively supplying an image signal to the pixel mW for each pixel 6-3 of the matrix display section. All of the pixel electrodes to which the outputs of each transistor are connected are located on one of a pair of flat plates that sandwich the liquid crystal, and each electrode is electrically separated and independent on the flat plate on which the electrode is placed. are doing. Among the flat plates that sandwich the liquid crystal,
A single common electrode is provided on the flat plate facing the above flat plate over the entire display section.

Here, the substrate potential of each transistor and the one-side electrode potential of the capacitor provided for each pixel are commonly connected to GNDf1.
However, the common electrode potential 6-4 of the liquid crystal display section is not the GND potential. As shown in FIG. 4, partial views of an example in which transistors and capacitors are configured for each pixel are shown in FIGS. 6 and 7.

FIG. 6 is a sectional view of a pair of flat plates sandwiching a liquid crystal on the side where electrodes are arranged in a matrix and separated for each white pixel. In the figure, 7-1 is a silicon substrate. 7-2 is 7-
1 is a diffusion layer of the opposite conductivity type, and 7-3 is a diffusion layer of the same conductivity type as 7-1, which functions as a stopper and a capacitor electrode. Further, 7-4 is a gate oxide film, and its film thickness is about 400 to 2,000 .ANG. 7-5 is polysilicon, 7-5 (a) is the gate flili of the MOS transistor, and 7-5 (b) is the W of the capacitor.
lm. 7-6 is a field oxide film, 7-7 is an insulating film, and 7-8 is an aluminum electrode. In FIG. 6, the transistors that switch each pixel are composed of silicon gate MOS transistors, and
The electrodes of the capacitor arranged in parallel with each pixel of the liquid crystal are the silicon substrate itself and polysilicon 7-5 (b).

In this case, the silicon substrate is held at GND potential, and the sixth
As shown in the figure, the one side electrode of the capacitor and the substrate potential of the transistor match and become GND level.

FIG. 7 shows a plan view of the drive circuit arranged in a 7-trix pattern, and the AA' cross-sectional view in the figure corresponds to FIG. In the figure, 8-2 to 8-8 correspond to 7-2 to 7-8, respectively. Further, in FIG. 7, the drain electrode 7-8 (b) in FIG. 6 is omitted so as not to complicate the drawing. In FIG. 7, the pixels are areas indicated by two-dot chain lines. Therefore, the so-called pixel electrode that applies voltage to the liquid crystal is connected to a transistor or a signal [8-5(a)
, 8-8(a), etc., and are arranged above the pattern in FIG. 7 almost as shown by the two-dot chain line. As mentioned above, 7-1 is a monolithic silicon crystal substrate, but there are various other methods for configuring the circuit shown in FIG. 5, including thin film technology. Fifth
In the figure, each transistor is composed of a MOSFET, but it may also be a switching element.

Next, FIG. 8 shows an example of a signal waveform according to the present invention. In the figure, both 9-1 and 9-2 are image signals. 9-6
The one-dot chain line shown in 2 indicates the potential on the common electrode side of the liquid crystal matrix display body, and the voltage polarity of the image signal applied to each matrix image electrode of the liquid crystal is repeatedly inverted at the same period. For example, in the case of image signals for television broadcasting, one screen of video signal is taken as one frame, one frame is further divided into two fields, and interlaced scanning of the screen is performed for each field. Here, in FIG. 8, for example, 9-
1, it is assumed that t is aimed at one horizontal scanning line of one image signal of one frame including the first and second fields.

9-2 is the next one following the signal for one frame.
These are image signals corresponding to the same display portion of one image signal for a frame.

9-3 is a sampling synchronization signal that represents one image, and the period is not shown in 9-4.
It corresponds to the period in which the duty is displayed. 9-5 is TV picture 1
corresponds to the horizontal retrace period of the image signal.

In the vertical axis of FIG. 8, 0 potential, that is, 9-11, is the potential of the display substrate 7-1, for example, and 9-10 is the display body circuit voltage corresponding to 9-11. In this case, the switching transistor arranged for each pixel in FIG. 5 is, for example, a P-channel enhancement MO3FET.
Can be done. When 9-10 is set to the potential of base W and 7-1, the switching transistor may be constructed of an N-type MOS.

The amplitude of the image signal 9-1 is from the wavy line 9-7 to the wavy line 9-8.
It's between. 9-7 corresponds to black of the image signal, and 9-8 corresponds to white. Regarding the linearity of the signal, it is sufficient to prevent the linearity of the original image signal from being distorted by the liquid crystal by interposing an amplifier that is corrected based on the correlation characteristic between the applied voltage of the liquid crystal and the display contrast. Picture rib RG No. 9-1
The purpose of applying 9-2 and 9-2 alternately to each liquid crystal display pixel electrode is to extend the life of the display by AC driving the liquid crystal. When converting the signal into an alternating current signal to drive the liquid crystal, flickering of the displayed image occurs due to the alternating voltage drive of the liquid crystal. This is because the direction in which the electric dipole of the liquid crystal molecules faces also changes in response to the reversal of the applied voltage polarity. The following methods can be considered as methods for reducing flickering or making it effectively negligible.

In other words, the phase may be reversed at a cycle faster than the eye can respond.

(1) The phase is inverted at the frame period, and the frame period is approximately 30 Hz or more.

(2) Invert each pixel or scanning line within one frame period to increase the effective inversion period.

Furthermore, various methods can be considered depending on the above application. When displaying television images in a matrix, the number of images constituting the matrix may be smaller than the effective number of pixels (or resolution) of the television video signal. At this time, for example, if one liquid crystal image is constructed from a matrix for one field (1/2 frame) of a TV video signal, the phases of the signals for the first field and the second field are inverted, and two frames are displayed on the same pixel. It becomes possible to display a signal for one pulse at a frequency of 60H2. Although the resolution in terms of image quality is reduced, flickering due to the difference in original image signals is canceled by the response performance of the liquid crystal itself, and an average image of the first field and the second field is displayed. Furthermore, in the method (2), the polarity direction is switched for each pixel, and the image display signal within one frame is selected to be both positive and negative polarity signals, and the AC cycle of each pixel is set to 1. In units of frames, the linearity of the amplifier or the linearity of the switching characteristics of the transistor provided in each pixel depends on the operating voltage width (9
-11 to 9-10), the nonlinearity from the viewpoint of display effect can be effectively ignored.

The common electrode potential is 9- for waveform 9-1 and waveform 9-2.
6(a) and 9-6(b). That is, the potential of the common a electrodes is alternated between 9-6(a) and 9-6(b) at the polarity reversal period of the signal that drives the liquid crystal.

The effects of the above embodiment will be described in detail below.

As shown in FIG. 9(a), in the conventional driving method, the polarity of the video signal 4. is inverted for each field with respect to the fixed common electrode potential V(,). A[(u
As ■4. In addition, the level of Vat was required as the level of transistor data 1-tli.

On the other hand, in this embodiment, as shown in FIG. 9(b), since the common fliim is made to fluctuate at two levels Uu between VO2 for each field, the video signal v-m
Even if the polarity of is inverted for each field, the power supply potential for the video signal may be at the level 12, which is half of the V□, and the gate potential of the transistor may be VO2, which is half the VGI.

In addition, in general, a transistor, as shown in FIG. 9(C),
It has parasitic capacitance ff1c+, C2. Due to such capacitive coupling, the following offset voltage ΔV is generated in the liquid crystal electrode.

AV=Vc-C+/(C++CI)CL is the capacitance of the liquid crystal.

Since this voltage Δ■ is always unidirectional, the signals applied to the liquid crystal appear to be asymmetrical for each field. This asymmetry causes so-called flicker. From the above formula, the offset voltage ΔV is the gate voltage v6
Because it depends on v.

The lower the value, the less noticeable the flicker will be.

In order to solve this problem, in the present invention, as described above, the gate voltage can be significantly reduced compared to the conventional method, so that the effect of making this flicker less noticeable can be obtained.

By setting the potential and inverting the image signal as described above, the operating voltage or power supply voltage of the liquid crystal display drive circuit can be set to approximately the voltage Vs+α necessary for driving the liquid crystal, thereby enabling AC driving. Here, the elements of a include the threshold voltage of the drive circuit transistor shown in FIG. 5 and the channel resistance value when the transistor is turned on. In order to reliably write a signal corresponding to an image within the sampling period, it is necessary to set the gate voltage level higher than the threshold voltage with respect to the drain signal level. Game+-yar standing 9-10
When the drain potential is 9-8 (a) and 9-8 (
In case b), a difference occurs in the response speed of image signal writing. Therefore, in the present invention, 9-6(a) or 9-8(b
), it is proposed to set the potential of 9-10 to more than twice the threshold potential of the transistor. In particular, when outputting a television video signal to the liquid crystal display device according to the present invention,
One horizontal scanning signal time is 63.5 μsec, and this internal line time is about 10 μsec. Therefore, the writing time for each pixel is taken within the retrace period of 10 μsec, and is limited to about a divisor B sec. Conventionally, as shown in Japanese Unexamined Patent Publication No. 550-1O993Ft, 10, two 2-4 drain drive circuits are provided in parallel, and during a period when data is being sampled in one circuit, data is already sampled in the other circuit. There was a method to write the data that was displayed to the pixels. In this case, the writing time is 6
It is 3.5 μsec.

In the present invention, the data sampling drain drive circuit 6-2 simplifies the circuit by requiring one sampling circuit for each output. For this purpose, as mentioned above, the gate applied signal voltage is increased.
This ensures that errors do not occur during writing due to differences in input image signal levels, and that pixel data can be rewritten correctly within the retrace period. When the transistor is a P-channel type MO3, the gate applied signal potential or circuit potential is set to be lower than the lowest level of the drain signal and at least twice the transistor threshold voltage. In the case of N-channel MO5, on the contrary, the potential is set high.

FIG. 10 shows an embodiment of a circuit that implements the above description. 10-2.10-3.10-4 is an image signal amplifier, 1
0-5.10-7.10-8 is block 6-2 in Figure 5
corresponds to 10-6 is a changeover switch circuit;
-6 output becomes the image signal input of FIG. 5, 6-8.

The operation will be explained below. ]0-1 is the original image signal input, 1
0-2 is an initial stage amplifier, and 10-9 has an amplification factor adjustment terminal. 10-3 and 10-4 are differential amplifiers. 10-3
The same signal, ie, the 10-2 output, is coupled to the positive input terminal of 10-4 and the negative input terminal of 10-4. 10-3 negative polarity input terminal and 10-4 positive polarity input terminal are combined,
There are terminals at 0-10. 10-3 and 10-4 are
It is set in advance so that almost the same characteristics can be obtained as an amplifier. The 10-10 terminal is a terminal for adjusting the brightness of the image displayed by the liquid crystal to #7 and 1, and a variable DC voltage is applied thereto. For example, each output signal of 10-3.10-4 corresponds to FIG. 8, 9-1 and 9-2, respectively. At this time, 10-9 adjusts the difference between 9-8 and 9-7, that is, the amplitude, in other words, the contrast of one image on the front screen. 10-1
0 adjusts the difference between 9-7 and 9-6. 10-3 (
The gain of 10-4) may be set appropriately. Reference numeral 10-6 is a switch circuit, which switches the respective output signals of 10-3 and 10-4 and selectively outputs them when supplying an AC drive signal to the liquid crystal as described above. As the switch element, a transistor such as a bipolar or MOS transistor (and various other types can be considered), but when a semiconductor is used for the display substrate and the block 2-4 is housed inside the semiconductor substrate as shown in FIG. -6 is preferably made with a similar structure, such as a structure such as a so-called transmission gate.The same is true for the stage circuit 10-7.10-5 sequentially transmits a signal to control each switch element 10-7 For example, the circuit generates data from left to right and is composed of a shift register.10-8 is the image 1 sampled by the switch.
The image sampling signal is memorized and retained for each pixel? 1! This is a circuit for distributing to the poles. 10-8 and subsequent parts correspond to the liquid crystal matrix display section including the drive section, that is, FIG. 4.

FIG. 11 shows yet another embodiment. Figure 11 shows the first
The configuration of the amplifiers 10-2, 10-3, and 10-4 in Figure 0 is changed. Image signals 11-1 and 11-2 have substantially the same amplitude and opposite polarity. In the figure, the upper amplifier circuit (transistor 11-3.1l-5) and the lower amplifier circuit (transistor 11-13.1l-14) are as follows.
The circuit configuration and amplification characteristics are designed to match.

11-4 and 11-8 are variable resistors used for gain control of the amplification system, and adjust the contrast of the liquid crystal display image. 11
-4.11-8 is interlocked with 11-10 shown by the dotted line, and can be manually adjusted from the outside.

11-7 and 11-9 are variable resistors that control the output potential level, that is, change the brightness of the liquid crystal image display;
-11, and can be adjusted manually from the outside. However, potential levels 11-7 and 11-9 operate in opposite directions, and their respective outputs maintain symmetry about level 9-6 as shown in FIG. 9, 9-1 and 9-2. 11-12 is the first
This is an image signal polarity changeover switch circuit corresponding to FIG. 10-6.

The present invention can also be realized by a configuration other than the circuit described as an example. Furthermore, the contrast and brightness can be adjusted manually as described in ``2'', or the gain or bias level can be adjusted by automatically detecting light by making the display level of the liquid crystal correspond to the reference pattern display signal level. Naturally, automatic control is also possible.

In the detailed description of the present invention, as shown in FIG. This can be realized by configuring each element on a glass substrate or by other methods depending on technology. In Fig. 4, the transistor provided for switching each pixel is one MO5 type transistor, but in order to improve the linearity, response speed, operating voltage, etc. of the element, P type and N type transistors are used. It is also possible to perform switching by combining two types of MOSFETs in a nine-capture configuration. Of course, M
It is also possible to configure it with elements other than OSFET.

In Fig. 4, a capacitor is placed in parallel with each pixel of the liquid crystal, but in this case, as mentioned earlier, the picture electrode of the capacitor is not connected completely in parallel with the liquid crystal pixel electrode, but the common electrode side The potentials are set separately for each. This is because by adopting the structure shown in FIG. 5, the common side electrode of the capacitor can be replaced by the substrate. At this time, the polarity and magnitude of the bias potential applied to the capacitor in accordance with the image signal applied to the liquid crystal pixel are different from the bias potential of the liquid crystal pixel electrode, but the effective electrical characteristics related to display are shown in Figure 1. This has the same effect as the case shown in .

Regarding the liquid crystal used in the display device according to the present invention, TN
Although I have only explained the type liquid crystal, the DSMS mentioned at the beginning
The operating performance of GH and other liquid crystals remains basically the same.

〔Effect of the invention〕

As described above, in the present invention, liquid crystal is sealed between a pair of substrates,
A common transparent electrode is formed on one of the substrates, a plurality of pixel electrodes arranged in a matrix are formed on the other substrate, and a switching element is connected to the pixel electrode. In a liquid crystal display device, an image display signal generating means for inverting the polarity of the pixel display signal in synchronization with a field period of the image display signal and supplying the polarity-inverted image display signal to the pixel electrode; A two-level voltage that is inverted in synchronization with the cycle is generated, and the inverted two-level voltage is used as a common electrode signal to be applied to the common electrode Cj (
Since the field period is set to be less than 172 times the frame period of the image signal, even if the voltage required to drive the liquid crystal display is reduced to less than half of the conventional voltage, the liquid crystal Good display can be obtained without affecting the display quality. In addition, since the inversion timing of the image signal and the common signal is performed in a field period having a period of 1/2 or less of the frame period, a shift in one image due to inversion and screen flickering due to alternating driving may occur. This has the effect of making it possible to obtain stable images over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a conventional display circuit diagram. FIG. 2 is a conventional signal diagram. FIG. 3 is another conventional display circuit diagram. FIG. 4 is a block diagram showing one embodiment of the present invention. FIG. 5 is an example of a display circuit diagram according to the present invention. FIG. 6 is an example of a partial cross-sectional view of a display device. FIG. 7 is a plan view of FIG. 6. FIG. 8 is a signal waveform diagram in an embodiment of the present invention. FIGS. 9(a) to 9(C) are a comparison diagram and a schematic circuit diagram of the 1g waveform of the conventional invention. 10 and 11 are circuit diagrams for implementing the present invention. 5-12...7 Trix display section 7-1...Silicon! Temporary R-8 (a) ... Data line for driving matrix display 8-5 (a) ... Clock line for driving seven matrix display 8-5 (b) ... Capacitor electrode 3-1.9
-1.9-2...Image signal 10-2...Image signal amplifier 10-3.104, differential amplifier and above Applicant Seiko Epson Corporation Representative Patent attorney Kizobe Suzuki (rIh1 person) )V Figure 6 (α) Figure 9 Figure 10

Claims (2)

[Claims] (1) A liquid crystal is sealed between a pair of substrates, and on one of the substrates, there are multiple scanning lines and multiple signal lines arranged in a matrix, and the intersections of the scanning lines and the signal lines. In a liquid crystal display device in which a switching element and a pixel electrode are formed, and an image display signal is supplied to the pixel electrode every frame, the phase is inverted in units of pixels or scanning lines within one frame period. A liquid crystal display device featuring: (2) Switching the polarity direction for each pixel, selecting so that the image display signal within one frame is both a positive polarity signal and a negative polarity signal, and setting the alternating current cycle of each pixel in one frame unit. The liquid crystal display device according to claim 1.