JPH07120145B2 - Liquid crystal display device and amplifier circuit for liquid crystal display device - Google Patents

Description

Detailed Description of the Invention

The present invention relates to a liquid crystal display device using a matrix type liquid crystal display panel , and particularly to a pixel of the liquid crystal display device.
The present invention relates to the configuration of an amplifier circuit for an image signal to be supplied.

[0002]

2. Description of the Related Art Various display devices have been devised or put into practical use by utilizing the electro-optical effect of liquid crystals. These are due to a combination of alignment characteristics of liquid crystal molecules, dielectric anisotropy, optical anisotropy, etc., and are commonly known as DSM, TN, G
There are names such as H. The common features of these liquid crystals are that they have a light receiving type display effect, have a relatively high resistance, and that the threshold value in the display characteristics is slow or unstable with respect to each parameter. Here, the light-receiving type and the high resistance are the reason why the liquid crystal is superior to other display bodies and is practically used as a display body, but on the contrary, the threshold characteristics are inferior to those of other display elements. , The driving conditions of liquid crystal are complicated and difficult. Further, the fact that the life for DC driving is short is another factor that makes driving conditions difficult.

FIG. 1 is a circuit diagram around a display panel showing a conventional embodiment. For example, reference SID77DIGEST P.
Examples can be found in 64-65 and the like. In the figure, 2-1 is an image signal input such as a television video signal, 2-2 is a sync separation signal,
A circuit 2-3 generates a control signal such as a timing clock from the sync separation signal. Reference numerals 2-4 and 2-5 are circuits for controlling the vertical lines or the horizontal lines of the matrix display section to distribute and scan the display signal to each matrix pixel. Reference numeral 2-4 is a drain drive circuit that converts the serial image signal input from 2-1 into parallel signals and supplies the parallel image signals to the drain side of the transistor connected in series to each pixel. Reference numeral 2-5 is a gate drive circuit that sequentially turns on and off the gates of the transistors connected in series to each pixel in accordance with 2-3 output clocks for each line to read an image signal into the pixel. The drains 2-6 on the output side of the transistors arranged in each matrix are coupled to the respective pixel electrodes of the liquid crystal display. Reference SID78DIG
As described in EST P96-97, conventionally , in the matrix display by the circuit of FIG. 1, the liquid crystal drive is DC drive. In FIG. 1, among the electrodes sandwiching the liquid crystal of the liquid crystal matrix display unit, the electrode facing each pixel electrode is a common electrode over the entire display surface,
The electric potential is set to the GND level and coincides with the electric potential of the common side electrode of the substrate of the MOS transistor and the capacitor arranged in parallel. For this reason, the liquid crystal material needs to be treated with a redox agent or the like for the purpose of maintaining a long DC life.

FIG. 2 shows the relationship between the signal waveform and the potential in the circuit of FIG. 3-1 is an image signal supplied to the terminal 2-1, and 3-2 is a synchronizing signal when the image signal is sampled for each data line of each matrix in the block 2-4. The horizontal axis t represents time, and the vertical axis V represents voltage. Reference numeral 3-3 represents a black level of the image signal and 3-4 represents a white level, which correspond to the threshold voltage and the saturation voltage of the liquid crystal, respectively. Voltage 0 corresponds to GND in FIG. 1 and is the substrate and common electrode potential.

Further, another conventional circuit example related to the present invention is shown in FIG. Specifically, SDI78DIGEST P9
Examples can be found in 4-95. In FIG. 3, 4-1 is shown in FIG.
2-1 corresponds to the image signal input. 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 input 4-1 is converted into an image signal in a band corresponding to the display performance of the corresponding display panel through a low pass filter and an amplifier, and then digital code converted by an A / D converter. Reference numeral 4-8 outputs the converted image digital image data in parallel to each data line of the matrix. The parallel output data is input to the D / A converter provided for each data line and restored to 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 (voltage-contrast) correlation characteristic of the liquid crystal and the contrast of the image signal match. Further, the D / A output is a buffer amplifier 4
It is input to -12. An offset bias level adjusting circuit 4-10 adjusts a reference level 4-12 so that the reference level of the image signal corresponds to the vicinity of the threshold value of the liquid crystal and outputs the image signal to the data line. Reference numeral 4-6 is a sync separation circuit, 4-7 is a timing signal generation circuit, and 4-13 is a circuit for controlling a clock line of the matrix display portion, which corresponds to 2-5. 4-16
Is a display matrix portion, and the configuration is the same as 2-7 in FIG. In the circuit example shown in FIG. 3, the liquid crystal is driven by direct current as in FIG. or,
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, and the signal level is adapted to the characteristics of the liquid crystal display. Is possible.

[0006]

In the conventional circuit as described above, a D / A converter for adjusting the gain and a buffer amplifier for adjusting the offset are provided for each data line, and the same control is performed for each. It is adjusted by the signal line. Therefore, as is clear from FIG. 3, a number of D / A converters and buffer amplifiers equal to the number of data lines are required,
The data line drive circuit becomes extremely complicated. Furthermore, each D /
The gains and other amplification characteristics of the amplifiers constituting A or the buffer must be the same. It is almost impossible to manufacture the device in which the characteristics of the amplifiers are the same in the unadjusted state. Therefore, it is necessary to adjust each amplifier in advance.

The present invention provides an image display device that improves the conventional drawbacks and makes full use of the display performance of liquid crystals. According to the invention, the document Display c
onf. Even if the number of matrix scanning lines is significantly increased compared to the so-called dynamic driving method of 1976 p51,
The display contrast performance of the liquid crystal is not impaired at all, and the applied voltage required for driving the display does not increase. Further, the screen flicker (so-called flickering) does not occur. Further, since the present invention drives the liquid crystal by alternating current,
It is possible to maintain the life of the liquid crystal for a long time, and it is not necessary to mix an additive such as a redox agent. The circuit embodying the present invention is much simpler than that shown in FIG. 3, and the adjustment of contrast, brightness, etc. can be performed very easily. It is highly practical and has a variation as shown in FIG. Does not have a factor of.

[0008]

The present invention is, firstly, to provide a pair.
Liquid crystal between the two substrates, and one of the substrates in a matrix
In a liquid crystal display device having a pixel electrode formed,
Phase inversion of the image signal supplied to the pixel electrode every predetermined period
And an output circuit for outputting the original image signal.
A first amplifier for inputting a signal to the positive input terminal,
A second amplifier for inputting the image signal to the negative input terminal;
The outputs of the first amplifier and the second amplifier are set to the predetermined period.
Switch means for outputting the image signal by switching for each
A negative input terminal of the first amplifier and the first amplifier
A DC voltage of a predetermined level is applied to the positive input terminal of the second amplifier.
Is applied . Second, a pair of groups
Pixels in a matrix on one of the substrates with liquid crystal between the plates
In a liquid crystal display device having electrodes, the pixel
The phase of the image signal supplied to the electrodes is inverted every predetermined period.
An amplifier circuit for outputting is provided, and the amplifier circuit is configured so that one phase
A first amplifier for inputting an original image signal having a state, the
Has one phase state and the other phase state inverted
A second amplifier for inputting an original image signal and the first amplifier
And switching the output of the second amplifier every predetermined period
Switch means for outputting the image signal,
The first and second amplifiers set the output potential level
Characterized by comprising resistance means interlocking with each other.
It Thirdly, a pixel that drives the liquid crystal of the liquid crystal display device.
The phase of the image signal supplied to the electrodes is inverted every predetermined period.
In an amplifier circuit for a liquid crystal display device that outputs, the amplifier circuit
Is a first amplifier that inputs the original image signal to the positive input terminal.
And a second inputting the original image signal to the negative input terminal
Output of the first amplifier and the second amplifier
A switch for outputting the image signal by switching at every predetermined period.
Switch means, and a negative input terminal of the first amplifier.
A predetermined level on the positive input terminal of the child and the second amplifier.
It is characterized by being applied with a direct current voltage. Fourth
Is supplied to the pixel electrode that drives the liquid crystal of the liquid crystal display device.
A liquid crystal display that inverts the phase of the image signal
In the amplifier circuit for the display device, the amplifier circuit is
A first amplifier for inputting an original image signal having a state, before
Note: It has one phase state and the other phase state which is the phase inversion.
Second amplifier for inputting the original image signal, and the first amplifier
The output of the power supply and the second amplifier at each of the predetermined periods
And a switch means for outputting the image signal,
The first and second amplifiers set the output potential level.
Characterized in that it is provided with interlocking resistance means for
To do.

[0009]

FIG. 4 is a block diagram showing an overall view of a television receiver using the liquid crystal image display device according to the present invention. In the figure, reference numeral 5-1 is a tuner section for selecting a frequency of a predetermined channel from a received radio wave input from an antenna. Reference numeral 5-2 is a circuit from the intermediate frequency amplifier to video detection, 5-4 is a circuit for audio intermediate frequency, detection, output, etc., and 5-5 is a circuit for separating horizontal, vertical and other synchronizing signals from the video signal. . A video amplification circuit block 5-3 according to the present invention outputs a liquid crystal display image signal to the matrix display section data signal latch circuit 5-8 in the subsequent stage. 5
-9 is a data line drive circuit. The reference numerals 5-6 and 5-7 receive the output of the synchronizing signal separation circuit 5-5 and supply a data latch signal to 5-8 and a timing signal for driving the matrix display clock line (horizontal line) to 5-10. To do. 5
A power source -11 supplies a common electrode voltage, which will be described later, to the common electrode 5-13 (dashed line). Reference numeral 5-12 represents a matrix type liquid crystal display panel, the details of which are as shown in FIG. 6-1 is a gate drive circuit, 6-2 is a drain drive circuit, and a transistor for selectively supplying an image signal of a pixel electrode is supplied to each pixel 6-3 of the matrix display portion. The electrodes of the pixels to which the outputs of the respective transistors are coupled are all located on one of the pair of flat plates that sandwich the liquid crystal, and the electrodes are electrically isolated and independent on the flat plate on which the electrodes are arranged. ing. A single common electrode is provided over the entire display unit on the flat plate facing the flat plate among the flat plates sandwiching the liquid crystal. Here, the substrate potential of each transistor and the electrode potential on one side of the capacitor provided for each pixel are in common with the GND potential, but the liquid crystal display section common electrode potential 6-4 is not the GND potential. Figure 4
6 and 7 show partial views of an example in which the transistor and the capacitor are configured for each pixel as described above.

FIG. 6 is a cross-sectional view of a pair of flat plates sandwiching a liquid crystal, the flat plate on the side having electrodes which are separated for each pixel and arranged in a matrix. In the figure, 7-1 is a silicon substrate. 7-
Reference numeral 2 is a diffusion layer having a conductivity type opposite to that of 7-1, and 7-3 is a diffusion layer having the same conductivity type as 7-1, which serves as electrodes of a stopper and a capacitor. Further, 7-4 is a gate oxide film having a film thickness of about 400 to 2000. 7-
Reference numeral 5 is polysilicon, 7-5 (a) is a gate electrode of a MOS transistor, and 7-5 (b) is an electrode of a capacitor. 7-6 is a field oxide film, 7-7 is an insulating film,
7-8 is an aluminum electrode. In FIG. 6, the transistor for switching each pixel is composed of a silicon gate MOS transistor, and the electrode of the capacitor arranged in parallel with each pixel of the liquid crystal is the silicon substrate itself and the polysilicon 7-. 5 (b). In this case, the silicon substrate is held at the GND potential, and one side electrode of the capacitor and the substrate potential of the transistor coincide with each other and reach the GND level, as shown in FIG.

FIG. 7 is a plan view of the driving circuits arranged in a matrix form, and a sectional view taken along the line AA 'in FIG.
Equivalent to. In the figure, 7-2 from 8-2 to 8-8
Corresponds to 2 to 7-8. Further, in FIG. 7, the drain electrode 7-8 (b) in FIG. 6 is omitted so that the drawing is not complicated. In FIG. 7, a pixel is an area indicated by a chain double-dashed line. Therefore, the so-called pixel electrode that applies a voltage to the liquid crystal is
Transistors or signal lines 8-5 (a), 8 running horizontally and vertically
It is arranged in a form insulated from −8 (a) and the like, as shown by a chain double-dashed line above the pattern of FIG. As mentioned above, 7-1 is a monolithic silicon crystal substrate,
There are various other methods of forming the circuit of FIG. 5, and thin film technology is one of them. In FIG. 5, each transistor is composed of a MOSFET,
Other switching elements may be used.

Next, an example of the waveform of the signal according to the present invention is shown in FIG.
Shown in. In the figure, 9-1 and 9-2 are both image signals. The alternate long and short dash line 9-6 indicates the liquid crystal matrix display body part common electrode side potential, and the voltage polarity of the image signal applied to each matrix image electrode of the liquid crystal repeats inversion at a certain cycle. For example, in the case of an image signal for television broadcasting, a video signal of one screen is set as one frame, the one frame is further divided into two fields, and the screen is interlaced for each one field. Here, in FIG. 8, for example, 9-1 corresponds to one horizontal scanning line in the image signal of one frame including the first and second fields. 9-2 is an image signal corresponding to the same display portion in the image signal for the next one frame following the signal for the one frame. Reference numeral 9-3 is an image sampling synchronization signal, and a period shown by 9-4 corresponds to a period for displaying one display pixel in the horizontal direction on the matrix display panel. 9-
5 corresponds to the horizontal blanking period of the television image signal. In the vertical axis of FIG. 8, 0 potential, that is, 9-11, is the potential of the display substrate 7-1 and 9-10 is the display unit circuit voltage corresponding to 9-11. In this case, the switching transistor arranged for each pixel in FIG. 5 can be configured by, for example, a P-channel type enhancement MOSFET. 9
When -10 is set to the potential of the substrate 7-1, the switching transistor may be composed of an N-type MOS.

The amplitude of the image signal 9-1 is between the wavy line 9-7 and the wavy line 9-8. 9-7 is a black image signal, 9-8
Corresponds to white. Regarding the linearity of the signal, the linearity of the original image signal may be prevented from being distorted by the liquid crystal by interposing an amplifier corrected by the correlation characteristic of the applied voltage of the liquid crystal and the display contrast. Image signal 9-
The purpose of alternately applying 1 and 9-2 to each liquid crystal display pixel electrode is to prolong the life of the display body by driving the liquid crystal with an alternating current. When the liquid crystal is converted into an AC signal to drive the liquid crystal, the display image flickers due to the alternating voltage driving of the liquid crystal.
This is because the direction in which the electric dipoles of the liquid crystal molecules face changes according to the reversal of the applied voltage polarity. The following methods are conceivable as methods for reducing flicker or making it effectively ignorable. That is, the phase may be inverted at a faster cycle than the eye responds. (1) The phase is inverted at the frame cycle so that the frame cycle becomes approximately 30 Hz or more. (2) The phase is inverted per pixel or scanning line within one frame period to increase the effective inversion period.

Further, various methods are conceivable depending on the above application. In the case of displaying a television image in a matrix, there are cases where it is attempted to realize the number of images constituting the matrix with a number smaller than the effective number of pixels (or resolution) of the television video signal. At this time, for example, if a liquid crystal image is formed by a matrix for one field (1/2 frame) of a television video signal, the signals for the first field and the second field are phase-inverted, and two fields for the same pixel are formed. It is possible to display the signal at a frequency of 60 Hz. Although the resolution as the image quality is reduced, the flicker caused by the difference between the 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. Further, in the method of (2), the polarity direction is switched for each pixel, and the image display signal in one frame is selected so as to have both the positive polarity signal and the negative polarity signal, and the AC cycle of each pixel is set to 1 In the case of a frame unit, even if the linearity of the amplifier or the switching characteristic of the transistor provided in each pixel is not sufficiently obtained in the operating voltage range (9-11 to 9-10). , Non-linearity in terms of display effect can be effectively ignored.

The common electrode potential has waveforms 9-1 and 9-2.
In contrast, 9-6 (a) and 9-6 (b) are changed and set. That is, the common electrode potential is alternated between 9-6 (a) and 9-6 (b) in the polarity inversion period of the signal for driving the liquid crystal.

The effects of this embodiment described above will be described in detail below. As shown in FIG. 9A, in the conventional driving method, the polarity of the video signal V _ds is inverted for each field with respect to the fixed common electrode potential V _c1 , so that V _d1 is used as the power supply potential for the video signal. The level is required, and the level of V _G1 is required as the gate potential of the transistor.

On the other hand, in this embodiment, as shown in FIG.
As shown in (b), since the common electrode potential is made to _fluctuate with a two-level potential between V _{c2 for} each field, the video signal
Even if the polarity of V _dS is inverted for each field, the power supply potential for the video signal may be the level of V _d2 which is half that of V _d1 , and the gate potential of the transistor is V _G2 which is half of V _G1. Good.

In addition, a transistor generally has a parasitic capacitance C ₁ as shown in FIG. 9 (c). Due to such capacitive coupling, the following offset voltage ΔV is generated in the liquid crystal electrode.

[0019]

[Number 1] _{△ V = V G · C 1} / (C 1 + C L) C L is the capacitance of the liquid crystal.

Since this voltage ΔV is always unidirectional,
The signal applied to the liquid crystal is apparently asymmetric for each field. This asymmetry causes so-called flicker. Since the offset voltage ΔV depends on the gate voltage V _G from the above equation, the lower the V _G is, the less the flicker becomes. With respect to such a problem, in the present invention, as described above, the gate voltage can be significantly reduced as compared with the related art, so that the effect of eliminating this flicker can be obtained. By setting the potential and inverting the image signal as described above, the operating voltage of the liquid crystal display body portion drive circuit,
Alternatively, the power supply voltage is set to about the voltage V _S + α required for driving the liquid crystal to enable AC driving. Here, the factors of α include the threshold voltage of the drive circuit transistor in FIG. 5 and the channel resistance value when the transistor is 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. The drain potential is 9-8 (a) with respect to the gate potential 9-10.
There is a difference in the response speed of writing the image signal between the case of 9 and the case of 9-8 (b). Therefore, in the present invention, it is proposed to set the potential of 9-10 to 9-6 (a) or 9-8 (b) at least twice the threshold potential of the transistor. In particular, when a television video signal is output to the liquid crystal display device according to the present invention, one horizontal scanning signal time is 63.5 μsec.
The inner retrace time is about 10 μsec. Therefore, the writing time to each pixel is limited to about several μsec, which is set within the blanking period of 10 μsec. Conventionally, for example, Japanese Laid-Open Patent Publication No. 50-10993 Fig. As shown in 10, two drain driving circuits 2-4 are provided in parallel, and while the data is being sampled in one circuit, the data already sampled in the other circuit is written to the pixel. was there. In this case, the writing time is 63.5 μsec.

In the present invention, the data sampling drain drive circuit 6-2 is simplified by providing only one sampling circuit for each output. Therefore, the gate applied signal voltage is increased as described above so that an error does not occur during writing due to the difference in the input image signal level, and the pixel data can be correctly rewritten within the blanking period. When the transistor is a P-channel type MOS, the gate applied signal potential or the circuit potential is set to be lower than the lowest level of the drain signal by at least twice the transistor threshold voltage. In the case of N-channel MOS, on the contrary, the potential is set high.

FIG. 10 shows an embodiment of a circuit that realizes the above description. Reference numerals 10-2, 10-3, and 10-4 correspond to image signal amplifiers, 10-5, 10-7, and 10-8 correspond to block 6-2 in FIG. Reference numeral 10-6 is a changeover switch circuit, and the output of 10-6 becomes an image signal input of 6-8 in FIG.

The operation will be described below. Reference numeral 10-1 is an original image signal input, 10-2 is a stage amplifier, and 10-9 has an amplification factor adjusting terminal. 10-3 and 10-4 are differential amplifiers. The same signal, that is, the 10-2 output, is coupled to the positive input terminal 10-3 and the negative input terminal 10-4. 1
The 0-3 negative polarity input terminal and the 10-4 positive polarity input terminal are combined to form a terminal at 10-10. 10-3 and 10-4 are preset so that almost the same characteristics as the amplifier can be obtained. The 10-10 terminal is a terminal for adjusting the brightness of the display image by the liquid crystal, to which a variable DC voltage is applied. For example, the output signals 10-3 and 10-4 respectively correspond to 9-1 and 9-2 in FIG.
At this time, 10-9 adjusts the difference between 9-8 and 9-7, that is, the amplitude, in other words, the contrast of the surface image. 1
0-10 adjusts the difference between 9-7 and 9-6. 10-
The gain of 3 (10-4) may be set appropriately. 10-6
Is a switch circuit, which is a circuit that selectively outputs the output signals of 10-3 and 10-4 when supplying an AC drive signal to the liquid crystal as described above. The switch element may be a transistor such as bipolar or MOS, and various other methods, 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. It is desirable to make it with the same structure, and a so-called transmission gate or the like can be mentioned. The latter circuit 10-7 is also the same. Reference numeral 10-5 is a circuit for sequentially generating a signal for controlling each switch element 10-7, for example, from left to right, and is composed of a shift register. Reference numeral 10-8 is a circuit for storing and holding the image sampling signal sampled by the switch and distributing it to each pixel electrode. 10-8 and thereafter correspond to the liquid crystal matrix display unit including the drive unit, that is, FIG.

FIG. 11 shows still another embodiment. Figure 11
Is a modification of the configuration of the amplifiers 10-2, 10-3, and 10-4 in FIG. 11-1 and 11-2 are image signals having substantially the same amplitude and opposite polarities. In the figure, the upper amplification circuits (transistors 11-3 and 11-5) and the lower amplification circuits (transistors 11-13 and 11-14)
Are designed so that the circuit configuration and the amplification characteristics are the same. Reference numerals 11-4 and 11-8 are variable resistors for controlling the gain of the amplification system and adjust the contrast of the liquid crystal display image. 11-4 and 11-8 are interlocked by a dotted line 11-10, and can be manually adjusted from the outside. 11-7, 11
- 19 controls the output voltage level, i.e. a variable resistor for changing the brightness of the liquid crystal image display, in conjunction with a wavy line 11-11 can be adjusted manually from the outside. However, 11-7
When operating the potential level in the opposite direction to the 11-19, each output of the symmetry about the level 9-6 as shown in FIG. 9 in 9-1 and 9-2 are maintained. 11-12 is 10- in FIG.
6 is an image signal polarity changeover switch circuit corresponding to 6.

The present invention can also be realized by a configuration other than the circuits given as examples. Furthermore, the contrast,
The brightness adjustment can be controlled manually as described above, or it can be automatically controlled by automatically detecting the liquid crystal display level corresponding to the reference pattern display signal level and automatically controlling the gain or bias level. It will be possible. In the description of the embodiments of the present invention, as shown in FIG. 5, a silicon substrate is used as one flat plate sandwiching a liquid crystal, and a transistor is formed in the silicon substrate. Alternatively, for example, a thin film technology using a polycrystalline material is used. It is possible to realize each element by configuring each element on the glass substrate or by other methods. In FIG. 4, the transistor provided for switching each pixel is one M
Although it is an OS type transistor, in order to improve the linearity of the element, the response speed, the operating voltage, etc., two types of P-type and N-type MOSFETs can be combined in a complementary type for switching. Of course, it is also possible to configure with elements other than MOSFET.

In FIG. 4, a capacitor is arranged in parallel with each pixel of the liquid crystal, but in this case, both electrodes of the capacitor are not connected in parallel with the liquid crystal pixel electrode as described above, but are common. The electrode side potentials are set separately. This is because the common side electrode of the capacitor can be substituted by the substrate by adopting the structure of FIG. At this time, although the polarity and the magnitude of the bias potential applied to the capacitor according to the image signal applied to the liquid crystal pixel are different from the bias potential of the liquid crystal pixel electrode, the effective electrical characteristics related to the display are shown in FIG. It has the same effect as the case shown.

Regarding the liquid crystal used in the display device according to the present invention, only the TN type liquid crystal has been explained, but the operating performance of the first mentioned DSM, GH and other liquid crystals does not basically change. .

[0028]

As described above, according to the present invention, firstly , the pixel electrode
Output the image signal supplied to the
Amplifier circuit to input the original image signal to the positive input terminal.
Input the 1st amplifier and the original image signal to the negative input terminal
Output of the second amplifier, the output of the first amplifier and the second amplifier
The switch that outputs the image signal by switching the power for each predetermined period.
A negative input terminal of the first amplifier and a first
A DC voltage of a predetermined level is applied to the positive input terminal of the second amplifier.
Is applied. Secondly, the pixel electrode
Output the image signal supplied to the
The amplifier circuit that generates the original image signal with one phase state
The input first amplifier and the phase inversion of one phase state
The second phase inputting the original image signal having the other phase state
The output of the amplifier and the first and second amplifiers are output for a predetermined period.
Switch means for switching the image signal for each interval and outputting the image signal
And the first and second amplifiers set the output potential level
With interlocking resistance means for
is there. Therefore, in the first and third inventions,
And the DC voltage level applied to the inputs of the second amplifier are
In the second and fourth inventions, the first and second amplifiers
By adjusting the resistance means interlocking with each other,
The image signal of one phase and the image signal of the other phase.
The other output potential level can be adjusted relatively. Therefore, the image
Extends the life of the liquid crystal by reversing the polarity of the drive voltage of the liquid crystal.
And liquid for reverse driving as in the present invention for reducing flicker
In the crystal display device, the image signals of both phases are relatively
The balance can be adjusted and the brightness of the liquid crystal display image can be adjusted.
As a result, very good display quality can be provided. See you
Can be adjusted with a simple structure.

[Brief description of drawings]

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 an 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.

FIG. 8 is a signal waveform diagram according to an embodiment of the present invention.

9A to 9C are a signal waveform comparison diagram and a schematic circuit diagram of the conventional invention.

10 and 11 are circuit diagrams of an embodiment of the present invention.

[Explanation of symbols]

 5-12 Matrix Display Section 7-1 Silicon Substrate 8-8 (a) Matrix Display Driving Data Line 8-5 (a) Matrix Display Driving Clock Line 8-5 (b) Capacitor Electrode 3-1, 9-1 , 9-2 Image signal 10-2 Image signal amplifier 10-3, 104 Differential amplifier

Claims (8)

[Claims] 1. A liquid crystal between a pair of substrates, wherein one of the substrates is
Liquid crystal display with pixel electrodes formed in a matrix on a plate
In the device, the image signal supplied to the pixel electrode is phased at predetermined intervals.
An amplifier circuit for inverting and outputting is provided, and the amplifier circuit inputs the original image signal to the positive input terminal.
Input the first amplifier and the original image signal to the negative input terminal.
The second amplifier, the first amplifier and the second amplifier
The image signal by switching the output of the container every predetermined period.
And a switch means for outputting the negative voltage of the first amplifier.
For the polarity input terminal and the positive input terminal of the second amplifier
Is a liquid crystal display device characterized in that a predetermined level of DC voltage is applied . 2. A positive input terminal of the first amplifier and
The original image signal is applied to the negative input terminal of the second amplifier.
A third amplifier for outputting, the third amplifier being the source
Features an adjustment terminal for adjusting the amplitude of the image signal
The liquid crystal display device according to claim 1. 3. A liquid crystal between a pair of substrates, wherein one of the substrates is
Liquid crystal display with pixel electrodes formed in a matrix on a plate
In the device, the image signal supplied to the pixel electrode is phased at predetermined intervals.
An amplifier circuit for inverting and outputting is provided, and the amplifier circuit inputs the original image signal having one phase state.
A first amplifier that force, the one of the phase states and phase inversion
The second inputting the original image signal having the other phase state
Output of the first amplifier and the second amplifier
A switch for outputting the image signal by switching at every predetermined period.
Switch means and the first and second amplifiers are
Interlocking resistance means for setting the force potential level
A liquid crystal display device characterized in that it comprises a. 4. The first amplifier and the second amplifier
Is provided with resistance means for gain control interlocking with each other.
The liquid crystal display device according to claim 3, which is characterized in that. 5. A pixel electrode for driving liquid crystal of a liquid crystal display device.
Output the image signal supplied to the
In the amplifier circuit for liquid crystal display device, the amplifier circuit inputs the original image signal to the positive input terminal.
Input the first amplifier and the original image signal to the negative input terminal.
The second amplifier, the first amplifier and the second amplifier
The image signal by switching the output of the container every predetermined period.
And a switch means for outputting the negative voltage of the first amplifier.
For the polarity input terminal and the positive input terminal of the second amplifier
Is an amplifier circuit for a liquid crystal display device, wherein a DC voltage of a predetermined level is applied . 6. A positive input terminal of the first amplifier and
The original image signal is applied to the negative input terminal of the second amplifier.
A third amplifier for outputting, the third amplifier being the source
Features an adjustment terminal for adjusting the amplitude of the image signal
Amplification for liquid crystal display device according to claim 5
circuit. 7. A pixel electrode for driving liquid crystal of a liquid crystal display device.
Output the image signal supplied to the
In the liquid crystal display device amplifier circuit, the amplifier circuit receives the original image signal having one phase state.
A first amplifier that force, the one of the phase states and phase inversion
The second inputting the original image signal having the other phase state
Output of the first amplifier and the second amplifier
A switch for outputting the image signal by switching at every predetermined period.
Switch means and the first and second amplifiers are
Interlocking resistance means for setting the force potential level
The liquid crystal display device amplifier circuit characterized in that it comprises a. 8. The first amplifier and the second amplifier
Is provided with resistance means for gain control interlocking with each other.
A liquid crystal display device according to claim 7, characterized in that
Amplifier circuit.