JP2012208292A - Liquid crystal display device, electronic apparatus and data signal generating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress occurrence of a horizontal line to which a reverse tilt domain is connected.SOLUTION: A liquid crystal device 1 includes: a display panel 10 provided with a plurality of pixels Px; and a controlling circuit 50 provided with a video processing circuit 70. In a case where bright pixels Pxw of which data signal Vid corresponding to gradation specified by a video signal VIDEO is not less than a second voltage Vsat are adjacent to one another at opposite sides to visual directions L of dark pixels Pxb of which the data signal Vid corresponding to the gradation specified by the video signal VIDEO is less than a first voltage Vc, the video processing circuit 70 corrects the video signal VIDEO and generates the data signal Vid such that an application voltage applied to a liquid crystal 232 of the dark pixels Pxb becomes the first voltage Vc.

Description

  The present invention relates to a technique for reducing display defects in a liquid crystal display device.

The liquid crystal panel includes a pair of substrates having a constant interval, and a plurality of pixels are provided in a matrix. Specifically, a plurality of pixel electrodes are formed on one substrate so as to correspond to each of the pixels, and a common electrode common to the plurality of pixels is formed on the surface of the other substrate facing the one substrate. The A liquid crystal is provided between the common electrode and the plurality of pixel electrodes.
In the VA (Vertical Alignment) method and the TN (Twisted Nematic) method, the alignment state of the liquid crystal, that is, the inclination of the liquid crystal molecules constituting the liquid crystal is perpendicular to the pair of substrates generated between the common electrode and the pixel electrode. It is defined by a vertical electric field having a component in various directions. The transmittance or reflectance of the pixel is determined by the alignment state of the liquid crystal molecules controlled by the vertical electric field.

  By the way, in recent years, liquid crystal devices have become smaller and higher definition, and the pixel pitch has become narrower. When the pixel pitch is reduced, a horizontal electric field is generated between adjacent pixels in addition to a vertical electric field that controls the alignment state of the liquid crystal. When a lateral electric field is applied to liquid crystal molecules whose alignment state is controlled by a vertical electric field, alignment defects (reverse tilt domains) in which the liquid crystal molecules tilt in a direction different from the direction in which the liquid crystal molecules should originally tilt occur, resulting in display defects. There was a problem.

  In order to deal with such a problem of the reverse tilt domain, the shape of the light shielding layer and the opening is devised so that the reverse tilt domain occurrence region cannot be visually recognized (Patent Document 1), or calculated from the video signal A technique (Patent Document 2) or the like that clips a video signal higher than a setting by determining that a reverse tilt domain occurs when the average brightness value is equal to or less than a certain value has been proposed.

JP-A-6-34965 JP 2009-69608 A

However, in the method of reducing the influence of the reverse tilt domain by the structure of the liquid crystal panel such as the shape of the light shielding layer and the opening, the aperture ratio is lowered, so that there is a problem that sufficient luminance cannot be obtained.
On the other hand, in the case of a technique for clipping a video signal, a video signal having a high gradation value cannot be displayed on the liquid crystal panel, and thus there is a problem in that the brightness of the image is limited and the display quality is lowered such as the contrast of the image is lowered. Arise.

  Therefore, in view of the above-described circumstances, the present invention has an object to solve and prevent the occurrence of display defects due to the reverse tilt domain without causing deterioration in display quality.

  In order to solve the above-described problem, a liquid crystal display device according to the present invention is provided corresponding to a plurality of scanning lines, a plurality of data lines, and an intersection of the plurality of scanning lines and the plurality of scanning lines. A plurality of pixels, a video processing circuit for generating a data signal for defining a transmittance of each of the plurality of pixels so as to obtain a gradation to be displayed based on the video signal, and the data on the plurality of data lines A data line driving circuit for supplying a signal and a scanning line driving circuit for driving the plurality of scanning lines, and the direction in which the liquid crystal molecules are displaced based on the data signal when viewed from the direction perpendicular to the display surface is clearly seen When the direction is set, the video processing circuit is configured such that the applied voltage applied to the liquid crystal of one of the plurality of pixels is smaller than the first voltage, and is opposite to the clear viewing direction with respect to the one pixel. Applied to the liquid crystal of the pixel located at When the voltage is equal to or higher than a second voltage higher than the first voltage, the data signal is generated by correcting the voltage applied to the liquid crystal of the one pixel to be the first voltage. To do.

According to the present invention, a pixel (dark pixel) in which the applied voltage applied to the liquid crystal is smaller than the first voltage and a pixel (brighter) in which the applied voltage applied to the liquid crystal is greater than or equal to the second voltage greater than the first voltage. When the pixel is adjacent, correction is performed so that the applied voltage applied to the liquid crystal of the dark pixel becomes the first voltage. By performing such correction, the horizontal electric field generated between these two pixels can be reduced and the vertical electric field generated in the dark pixel can be increased as compared with the case where correction is not performed.
The transmissivity of a pixel is controlled by tilting the liquid crystal molecules of the pixel toward the clear viewing direction by a vertical electric field generated by a voltage applied to the liquid crystal of the pixel based on a data signal supplied to the pixel. However, when the potential difference between the voltage applied to the liquid crystal of a certain pixel and the voltage applied to the liquid crystal of a pixel adjacent to the certain pixel becomes large, the liquid crystal is generated by a lateral electric field generated between these two pixels. In some cases, the molecules are inclined to the opposite side of the clear vision direction, which should be inclined by the longitudinal electric field, and the orientation is disturbed. When the reverse tilt domain formed by the liquid crystal molecules in such a disordered orientation is enlarged, the user visually recognizes it as a display defect. This reverse tilt domain is likely to occur when the lateral electric field between the two pixels is large.
On the other hand, when the vertical electric field acts on the liquid crystal molecules, the liquid crystal molecules are in a stable state due to the regulating force by the vertical electric field. In this case, the liquid crystal molecules are not easily affected by the transverse electric field, and as a result, the reverse tilt domain is hardly generated.
According to the present invention, the correction reduces the horizontal electric field generated between the dark pixel and the bright pixel and also increases the vertical electric field generated in the dark pixel, so that the possibility of occurrence of a reverse tilt domain can be suppressed to a low level. It becomes possible.

Further, according to the present invention, a pixel (dark pixel) in which the applied voltage applied to the liquid crystal is smaller than the first voltage, and a pixel in which the applied voltage applied to the liquid crystal is equal to or higher than the second voltage greater than the first voltage. When the bright pixel is adjacent to the bright pixel and the bright pixel is located on the opposite side to the clear vision direction of the dark pixel, the dark pixel is corrected.
When the liquid crystal molecules are tilted in the opposite direction to the clear viewing direction due to the influence of the lateral electric field, the liquid crystal molecules are in the original state, that is, in the tilted state toward the clear viewing direction. It becomes difficult to return. Such a lateral electric field that tilts the liquid crystal molecules in the direction opposite to the clear viewing direction is generated between the dark pixel and the bright pixel located on the opposite side of the dark pixel in the clear viewing direction. Therefore, the reverse tilt domain is more likely to occur in the vicinity of the boundary between these two pixels when the bright pixels are adjacent to each other on the opposite side to the clear viewing direction when viewed from the dark pixels.
According to the present invention, when the dark pixel and the bright pixel are adjacent to each other, when the bright pixel is located on the opposite side to the clear vision direction of the dark pixel, the dark pixel is corrected. That is, the correction is performed on pixels that are highly likely to generate a reverse tilt domain, and the number of pixels to be corrected can be reduced. Since the first voltage different from the voltage corresponding to the gradation specified by the video signal is applied to the liquid crystal of the dark pixel by the correction, the corrected dark pixel has the gradation specified by the video signal. Different gradations are displayed. Therefore, when the correction is performed on a large number of pixels, the luminance change due to the correction is more likely to be visually recognized by the user.
Therefore, by reducing the number of pixels to be corrected as in the present invention, it is possible to reduce the possibility that the luminance change due to the correction will be visually recognized by the user, and the contour portion even when the image has light and shade It is possible to prevent the image from being blurred and display a clear image.

Note that the reverse tilt domain generated in one pixel often disappears after several frames. The reverse tilt domain that disappears in such a short period is not visually recognized by the user and does not cause a large deterioration in display quality.
However, a reverse tilt domain generated in a certain pixel is combined with a reverse tilt domain generated in a pixel adjacent to the certain pixel, and the combined reverse tilt domain is further combined with a reverse tilt domain generated in a neighboring pixel. In some cases, the reverse tilt domain develops into a “horizontal line” that is connected in a straight line in the horizontal direction and may exist for a long period of time. Such a horizontal line indicates that the dark pixel and the bright pixel adjacent to the opposite side to the clear direction of the dark pixel scroll to the right one pixel at a time on the opposite side to the clear direction of the dark pixel. Occurs like a tail.
According to the present invention, when a bright pixel is adjacent to the opposite side of the clear vision direction of the dark pixel, the dark pixel is corrected. When correcting dark pixels, even if a reverse tilt domain occurs in the corrected pixels, the size can be reduced. Therefore, the correction can prevent the reverse tilt domain generated in the corrected pixel from being combined with the reverse tilt domain generated in other pixels, and the possibility of the occurrence of a horizontal line can be suppressed to a low level.

  In the liquid crystal display device described above, when the transmittance of the pixel corresponding to the maximum value of the data signal is 100% and the transmittance of the pixel corresponding to the minimum value of the data signal is 0%, The first voltage is preferably a voltage that causes the transmittance of the pixel to be greater than 0% and not greater than 0.1%.

In the present invention, when the voltage applied to the liquid crystal of a certain pixel is corrected to be the first voltage, the value of the first voltage is determined based on the relative transmittance of the pixel.
The VT characteristic indicating the relationship between the relative transmittance of the pixel and the voltage applied to the liquid crystal differs depending on each display panel. If the first voltage is set to a certain fixed value, when the first voltage is applied to the liquid crystals of a plurality of different display panels, the relative transmittance of the pixels becomes different between the plurality of display panels. The display quality varies among the panels. Furthermore, when the first voltage is set to a fixed value, there is a possibility that the luminance change due to the correction is increased to be visually recognized by the user on some display panels due to such variations in display quality.
According to the present invention, by determining the value of the first voltage with reference to the relative transmittance of the pixel, even when there is a variation in VT characteristics between individual display panels, It becomes possible to keep the luminance change within a certain range. That is, since the influence on the luminance change when correction is performed can be made uniform for each display panel, the display quality of the display panel can be kept constant.

Further, the shape of the curve VT indicating the VT characteristics changes while maintaining the relative transmittance of the pixels at approximately 0% when the voltage applied to the liquid crystal is less than a certain level (for example, about 1.5 V or less). On the other hand, when the voltage applied to the liquid crystal exceeds a certain level, the relative transmittance of the pixel also rises rapidly.
According to the present invention, by setting the first voltage to a voltage at which the relative transmittance of the pixel is greater than 0% and 0.1% or less, the value of the first voltage can be set to a sufficiently large value. It becomes. That is, according to the present invention, a large voltage (first voltage) can be applied to the liquid crystal while minimizing the luminance change due to the correction, so that the reverse tilt domain can be effectively performed without degrading the display quality. Can be suppressed.

  In the liquid crystal display device described above, when the pixel adjacent to the first pixel in the direction opposite to the clear vision direction is the second pixel, the video processing circuit performs gamma correction on the video signal and outputs the first signal. Gamma correction means for generating, delay means for delaying the first signal corresponding to the first pixel to generate a second signal corresponding to the second pixel, and a value indicated by the first signal A determination unit that determines whether or not a value that is smaller than one voltage and the value indicated by the second signal is equal to or greater than a second voltage; and a determination result of the determination unit indicates affirmative, the first signal is It is preferable that correction means for generating the data signal by correcting the first voltage is provided.

According to the present invention, the video processing circuit includes the first pixel in the video signal input to the video processing circuit when a reverse tilt domain may occur between the first pixel and the second pixel. A data signal is generated by correcting the value defining the gray level so as to be a value corresponding to the first voltage. Thereby, generation | occurrence | production of a reverse tilt domain can be suppressed between a 1st pixel and a 2nd pixel.
The video processing circuit converts the video signal that defines the gradation to be displayed by the pixel into a data signal that defines the voltage value corresponding to the gradation to be displayed by the pixel. This conversion is performed with reference to, for example, a lookup table that associates the transmittance of the pixel with the voltage applied to the pixel. Accordingly, even when the value of the first voltage is determined based on the transmittance of the pixel, the voltage value corresponding to the transmittance of the pixel can be easily calculated by using the lookup table. it can.
That is, according to the present invention, it is possible to easily correct the video signal, and it is possible to easily set and change the setting of the pixel transmittance.

  In the liquid crystal display device described above, the video processing circuit may be configured such that the data signal is smaller than the first voltage for each of a predetermined number of pixels positioned on the clear vision direction side with respect to the one pixel. In some cases, it is preferable that the data signal is generated by correcting the data signal of the pixel to be the first voltage.

  According to the present invention, when a bright pixel is adjacent to the dark pixel on the side opposite to the clear vision direction, correction is performed on each of the plurality of pixels located on the clear vision direction side when viewed from the dark pixel including the dark pixel. Do. Accordingly, even when there are a plurality of dark pixels on the clear vision direction side of the dark pixels and a reverse tilt domain may occur in each of the plurality of dark pixels, by performing correction, The scale of the reverse tilt domain generated in each of the plurality of dark pixels can be reduced. Accordingly, it is possible to prevent reverse tilt domains generated in each of the plurality of dark pixels from being combined with each other to form a horizontal line.

  Next, an electronic apparatus according to the present invention includes any one of the above liquid crystal display devices. Such electronic devices include car navigation devices, personal computers, and mobile phones.

  Next, a data signal generation method according to the present invention corresponds to an intersection of a liquid crystal including liquid crystal molecules, a plurality of scanning lines, a plurality of data lines, and the plurality of scanning lines and the plurality of scanning lines. The data supplied to a liquid crystal display device comprising: a plurality of pixels provided; a data line driving circuit for supplying data signals to the plurality of data lines; and a scanning line driving circuit for driving the plurality of scanning lines. A data signal generation method for generating a signal, wherein when a direction in which the liquid crystal molecules are displaced based on the data signal when viewed from a direction perpendicular to a display surface is a clear vision direction, one of the plurality of pixels The applied voltage applied to the liquid crystal of the pixel is smaller than the first voltage, and the applied voltage applied to the liquid crystal of the pixel located in the direction opposite to the clear viewing direction with respect to the one pixel is greater than the first voltage. Determine if the voltage is over the second voltage When the determination result is affirmative, the data signal is generated by correcting the voltage applied to the liquid crystal of the one pixel to be the first voltage, and when the determination result is negative, the video A data signal designating a voltage to be applied to the liquid crystal of the one pixel so as to have a gradation indicated by the signal is generated.

  According to the present invention, even when a bright pixel is adjacent to the dark pixel on the opposite side to the clear vision direction, the voltage applied to the dark pixel is corrected so as to become the first voltage. It is possible to suppress the occurrence of reverse tilt domains in the vicinity of the boundary. In addition, such correction is performed only for pixels that are likely to generate a reverse tilt domain, and the change in the transmittance of the pixel before and after correction is suppressed to a small level. It is possible to suppress the possibility that the change will be visually recognized by the user.

1 is a block diagram illustrating a configuration of a liquid crystal device according to a first embodiment of the present invention. 3 is a timing chart showing the operation of the liquid crystal device. It is an equivalent circuit diagram of a pixel. It is a figure which shows the VT characteristic of a display panel. It is explanatory drawing which shows the generation | occurrence | production location of a reverse tilt domain, and the orientation of the liquid crystal molecule at the time of generation | occurrence | production of a reverse tilt domain. It is a figure explaining the change after generation | occurrence | production of a reverse tilt domain. It is a figure explaining the relationship between a correction voltage and the relative transmittance | permeability of a liquid crystal. It is a figure explaining the reverse tilt domain which generate | occur | produces when correct | amending. It is a figure explaining the change after generation | occurrence | production of the reverse tilt domain which generate | occur | produces when correct | amending. It is a block diagram which shows the structure of a video processing circuit. It is a figure which shows the relationship between a video signal and a data signal. It is a block diagram which shows the structure of the video processing circuit which concerns on 2nd Embodiment. It is a figure which shows the relationship between the video signal and data signal which concern on 2nd Embodiment. It is a figure explaining the change after generation | occurrence | production of the reverse tilt domain which generate | occur | produces when correct | amending. It is a block diagram which shows the structure of the video processing circuit which concerns on 3rd Embodiment. It is a figure which shows the relationship between the video signal and data signal which concern on 3rd Embodiment. It is a block diagram which shows the structure of the video processing circuit which concerns on 4th Embodiment. It is a figure which shows the relationship between the video signal and data signal which concern on 4th Embodiment. It is a figure explaining the change after generation | occurrence | production of the reverse tilt domain which generate | occur | produces when correct | amending. It is a figure which shows the VT characteristic of the display panel which concerns on the modification 4. It is a figure explaining the generation | occurrence | production location of the clear vision direction and reverse tilt domain of the liquid crystal device which concerns on the modification 5. FIG. It is a perspective view of an electronic device (personal computer). It is a perspective view of an electronic device (cellular phone). It is a perspective view of an electronic device (projector).

<A: First Embodiment>
Hereinafter, various embodiments according to the present invention will be described with reference to the accompanying drawings. In the drawings, the ratio of dimensions of each part is appropriately changed from the actual one.

FIG. 1 is a block diagram of a liquid crystal device 1 according to the first embodiment of the present invention. The liquid crystal device 1 can be mounted on an electronic device as a display body that displays an image. As shown in FIG. 1, the liquid crystal device 1 includes a display panel 10 that displays an image, and a control circuit 50 that controls the display panel 10.
The display panel 10 includes a display area 20 (display surface) having a plurality of pixels Px and a drive circuit 30 for driving the plurality of pixels Px. The driving circuit 30 includes a scanning line driving circuit 31 connected to the M scanning lines 21 and a data line driving circuit 32 connected to the N data lines 22. The control circuit 50 includes a scanning control circuit 60 that supplies various signals for controlling the display panel 10 and a video processing circuit 70 that generates a data signal Vid based on the video signal VIDEO.

The scanning control circuit 60 generates a Y transfer start pulse Dy and a Y clock signal Cly based on a synchronization signal Sync supplied from an external host device (not shown) and outputs the Y transfer signal to the scanning line driving circuit 31 and X transfer. A start pulse Dx and a dot clock signal Dclk are generated and output to the data line driving circuit 32 and the video processing circuit 70. Here, as shown in FIG. 2, the Y transfer start pulse Dy is a pulse signal that rises to a high level in a cycle of 1 frame F, and the X transfer start pulse Dx goes to a high level in a cycle of 1 horizontal scanning period H. It is a pulse signal that rises.
The video processing circuit 70 is supplied with a video signal VIDEO that defines gradations of a plurality of pixels Px included in the display area 20 from the host device. Then, the video processing circuit 70 temporarily stores the video signal VIDEO in the internal memory of the video processing circuit 70 in accordance with the control from the scanning control circuit 60, and then reads it in synchronization with the drive of the display panel 10 to obtain an analog data signal. Vid is generated and output to the data line driving circuit 32.

The display area 20 includes M (M is a natural number of 1 or more) scanning lines 21 extending in the X direction and N (N is a natural number of 1 or more) data extending in the Y direction intersecting the X direction. Line 22 and a plurality of pixels Px arranged in a matrix of vertical M rows × horizontal N columns corresponding to the intersection of each scanning line 21 and each data line 22.
The scanning line driving circuit 31 is means for sequentially scanning (selecting) a plurality of scanning lines 21 in units of rows. The scanning line driving circuit 31 is supplied with a Y transfer start pulse Dy and a Y clock signal Cly from the scanning control circuit 60. Then, as shown in FIG. 2, the scanning line driving circuit 31 sequentially generates the selection signals G [1] to G [M] by shifting the Y transfer start pulse Dy in accordance with the Y clock signal Cly. The output is sequentially performed for each of the M scanning lines 21.
Based on the data signal Vid supplied from the video processing circuit 70 and the X transfer start pulse Dx and the dot clock signal Dclk supplied from the scanning control circuit 60, the data line driving circuit 32 performs various operations as shown in FIG. Data voltages VD [1] to VD [N] defining the gradation of the pixel Px are generated and sequentially output to the N data lines 22 in the horizontal effective period Ha in one horizontal scanning period H. The data signal Vid is an analog signal obtained by time-division multiplexing the data voltages VD [1] to VD [N].

  FIG. 3 is an equivalent circuit diagram of the pixel Px. Here, the pixel Px located in the i-th row (i is a natural number satisfying 1 ≦ i ≦ M) and j-th column (j is a natural number satisfying 1 ≦ j ≦ N) is representatively illustrated. The pixel Px includes a liquid crystal element 230 including a selection transistor (switching element) 235, a liquid crystal 232 provided between the transparent pixel electrode 231 and the transparent common electrode 233, and a storage capacitor CO. The gate of the selection transistor 235 is connected to the i-th scanning line 21, one of the source and the drain is connected to the data line 22 in the j-th column, and the other of the source and the drain is connected to the pixel electrode 231. The holding capacitor CO has one end connected to the pixel electrode 231 and the other end connected to a capacitor line 24 held at a constant voltage, for example, the ground potential GND.

  When the selection signal G [i] supplied to the scanning line 21 becomes a high level, the selection transistor 235 is turned on, and the data signal Vid (specifically, the data voltage VD [j]) is transmitted from the data line 22 to the selection transistor. It is supplied to the pixel electrode 231 through 235. The data voltage VD [j] supplied to the pixel electrode 231 is held by the capacitor of the liquid crystal element 230 and the holding capacitor CO. In addition, during a period in which the selection signal G [i] supplied to the scanning line 21 is at a low level, the selection transistor 235 is turned off, and the data line 22 and the pixel electrode 231 are in a non-conductive state.

  Although not shown, the display panel 10 includes an element substrate and a counter substrate that are bonded to each other with a certain interval. The liquid crystal 232 is sealed in the gap between the element substrate and the counter substrate. In this embodiment, the scanning line driving circuit 31, the data line driving circuit 32, the scanning line 21, the data line 22, the selection transistor 235, and the pixel electrode 231 are formed on the element substrate, and the common electrode 233 is formed on the counter substrate. Are formed so as to be common to the plurality of pixel electrodes 231. A common potential Vcom is supplied to the common electrode 233.

  This embodiment assumes a normally black mode in which the liquid crystal 232 is a VA system and the pixel Px displays black (the relative transmittance of the pixel is 0%) when no voltage is applied to the liquid crystal element 230. In the following, the relationship between the voltage applied to the liquid crystal element 230 and the relative transmittance of the pixel and the movement of the liquid crystal molecules m when a voltage is applied to the liquid crystal element 230 will be described with reference to FIG.

FIG. 4A is a graph showing a VT characteristic that is a relationship between the voltage applied to the liquid crystal element 230 and the relative transmittance of the pixel Px. Here, the relative transmissivity of the pixel means that the transmissivity of the pixel when the voltage is not applied to the liquid crystal element 230 in the display panel 10 is 0% and the maximum voltage is applied to the liquid crystal element 230. Is obtained by scaling the transmittance of the pixel with 100%.
In the following, a voltage for setting the relative transmittance of the pixel to 0% is expressed as a black display voltage Vbk, and a voltage for setting the relative transmittance of the pixel to 100% is expressed as a white display voltage Vwt. In the present embodiment, the black display voltage Vbk is 0V, the white display voltage Vwt is 5V, and the common potential Vcom is set to 0V.

  FIG. 4B shows the alignment state of the plurality of liquid crystal molecules m constituting the liquid crystal 232 when the black display voltage Vbk is applied to the liquid crystal element 230 and when the white display voltage Vwt is applied. It is the shown schematic diagram. Since this embodiment is a VA system, when the black display voltage Vbk is applied to the liquid crystal element 230, the liquid crystal molecules m are arranged so that the major axis thereof is oriented almost perpendicular to the common electrode 233. Orient. On the other hand, when the white display voltage Vwt is applied to the liquid crystal element 230, the major axis of the liquid crystal molecules m is tilted toward the clear viewing direction L and is aligned in a direction almost parallel to the common electrode 233.

  Here, the clear viewing direction L is a direction representing a component parallel to the display panel 10 among the directions in which the liquid crystal molecules m are tilted when a voltage is applied to the liquid crystal element 230. When viewed from the direction L, the contrast of the image displayed on the display panel 10 is the highest. The clear viewing direction L is specified along the rubbing direction or the vapor deposition direction of the alignment film formed on the side facing the liquid crystal in the pair of substrates. In the present embodiment, the clear vision direction L is assumed to be a direction from the lower left to the upper right of the display panel 10 when viewed from a direction perpendicular to the display panel 10.

As described above, the liquid crystal 232 of the pixel Px is configured by the vertical electric field generated between the pixel electrode 231 and the common electrode 233 when the data voltage VD [j] is supplied to the pixel Px as the data signal Vid. The liquid crystal molecules m to be driven are controlled.
However, with the recent miniaturization and higher accuracy of the liquid crystal device, the interval between the pixels Px is narrowed, so that the potential difference between the data voltages VD [j] supplied to the two adjacent pixels Px is different. If it is large, a horizontal electric field in a direction parallel to the common electrode 233 may be generated between the pixel electrodes 231 of these two pixels Px.

  The liquid crystal molecules m are controlled so as to be tilted toward the clear vision direction L by the vertical electric field, but may be tilted in the opposite direction to the clear vision direction L due to the influence of the lateral electric field. For the liquid crystal molecules m in such a disordered state, it is difficult to control the alignment state by a vertical electric field. The region where the orientation is defective is a reverse tilt domain. In the pixel Px in which the reverse tilt domain is formed, the liquid crystal molecules m are not in the alignment state defined by the data voltage [j], and therefore, a gradation different from the gradation to be displayed is displayed. As a result, the display quality of the display panel 10 is degraded.

When the voltage applied to the pixel electrode 231 of a certain pixel Px is a small voltage such as the black display voltage Vbk, the pixel Px liquid crystal molecule m is in an unstable state that is not controlled by the vertical electric field, and is caused by the horizontal electric field. Be susceptible. Furthermore, in this case, the potential difference between the voltage applied to the pixel electrode 231 of a certain pixel Px and the voltage applied to the pixel electrode 231 of the pixel Px adjacent to the pixel increases, and therefore, between these two pixels Px. The lateral electric field generated in the case becomes larger.
Accordingly, the voltage applied to the liquid crystal element 230 of a certain pixel Px is a small voltage such as the black display voltage Vbk, and the optical saturation voltage (second voltage) is applied to the liquid crystal element 230 of the pixel Px adjacent to the pixel Px. When a voltage of Vsat or higher is applied, the orientation of the liquid crystal molecules m is disturbed due to the influence of the lateral electric field generated between these two pixels Px, and a reverse tilt domain is likely to occur.
Note that according to the standard JEITA ED-2521B established by the Japan Electronics and Information Technology Industries Association, “Measurement method of liquid crystal display panel and its constituent materials”, the optical saturation voltage Vsat is a relative transmittance of 90 pixels. It is an applied voltage when it becomes%.

With reference to FIG. 5, the details of the location where the reverse tilt domain occurs and the movement of the liquid crystal molecules m when the reverse tilt domain occurs will be described.
FIG. 5A is a diagram showing gradations to be displayed in one frame with 16 pixels Px of 4 rows × 4 columns and a reverse tilt domain generated in the 16 pixels Px. Here, the pixel Px displayed in white is a bright pixel Pxw in which the white display voltage Vwt is applied to the liquid crystal element 230, and the pixel Px displayed in black is a dark pixel in which the black display voltage Vbk is applied to the liquid crystal element 230. This is the pixel Pxb. As described above, the liquid crystal molecules m of the bright pixels Pxw are aligned in the clear vision direction L side, and the liquid crystal molecules m of the dark pixels Pxb are aligned in the direction perpendicular to the drawing.
Hereinafter, a pixel Px to which a voltage equal to or higher than the optical saturation voltage (second potential) Vsat is applied to the liquid crystal element 230 is referred to as a bright pixel Pxw, and a correction voltage (first voltage) Vc described later is applied to the liquid crystal element 230. A pixel Px to which a small voltage is applied is referred to as a dark pixel Pxb.

FIG. 5B is a schematic diagram illustrating a cross section obtained by cutting the 16 pixels Px shown in FIG. 5A along straight lines α to β passing through diagonal lines of the four pixels Px1 to Px4. Here, the pixels Px1, Px2, and Px4 are bright pixels Pxw to which the white display voltage Vwt is applied, and the pixel Px3 is a dark pixel Pxb to which the black display voltage Vbk is applied.
As shown in FIG. 5B, a horizontal electric field exists between the pixel electrode 231 of the dark pixel Px3 and the pixel electrode 231 of the bright pixel Px4. Due to the influence of the lateral electric field, the liquid crystal molecules m existing between the pixels Px3 and Px4 are in a state in which the tilt orientation is disturbed in the direction opposite to the clear vision direction L, and a reverse tilt domain is formed. When the liquid crystal molecule m becomes defective in alignment, it takes a certain time for the liquid crystal molecule m to return to the state of tilting toward the original clear vision direction L. Therefore, the reverse tilt domain continues for a certain period. Become.

The reverse tilt domain occurs in the vicinity of the boundary between the two pixels Px when the bright pixel Pxw is adjacent to the clear vision direction L as viewed from the dark pixel Pxb.
As shown in FIG. 5B, a lateral electric field also exists between the pixel electrode 231 of the pixel Px3 and the pixel electrode 231 of the pixel Px2. This lateral electric field is a lateral electric field that tends to tilt the liquid crystal molecules m toward the clear viewing direction L. Since the liquid crystal molecules m are originally controlled to be tilted toward the clear vision direction L side by the vertical electric field, the horizontal electric field disappears when tilted to the clear vision direction L side due to the influence of the lateral electric field. Thus, it is possible to quickly return to the original inclination (in the case where there is no lateral electric field). Therefore, in this case, the reverse tilt domain is difficult to be formed.

  Thus, the reverse tilt domain is the boundary between the pixels Px3 and Px4, that is, the boundary between the two pixels Px when the bright pixel Pxw is adjacent to the clear viewing direction L when viewed from the dark pixel Pxb. Occurs.

  When the reverse tilt domain occurs and continues for a long period of time, a display defect is visually recognized by the user. The period during which the reverse tilt domain persists depends on what tone image is displayed by the plurality of pixels Px existing in the vicinity of the occurrence location of the reverse tilt domain after the occurrence of the reverse tilt domain. Hereinafter, with reference to FIG. 6, the relationship between the gradation to be displayed by the plurality of pixels Px existing in the vicinity of the location where the reverse tilt domain occurs and the duration of the reverse tilt domain will be described.

FIGS. 6A and 6B illustrate how the reverse tilt domain generated in the Kth frame (K is a natural number of 1 or more) changes during the four frames up to the K + 3th frame thereafter. FIG. In FIG. 6, the dark pixel Pxb is displayed in black, the bright pixel Pxw is displayed in white, and the reverse tilt domain is displayed in diagonal lines.
When the image changes continuously as shown in FIG. 6A, that is, the dark pixel Pxb is scrolled to the right by one pixel per frame, and the bright pixel Pxw adjacent to the dark pixel Pxb is also one pixel per frame. When scrolling to the right one by one, the reverse tilt domain gradually expands and remains for a long time.

  Specifically, in the Kth frame, a reverse tilt domain occurs near the left side and the lower side of the pixel Px1, and then, in the K + 1th frame, a reverse tilt domain occurs near the left side and the lower side of the pixel Px2. Then, the reverse tilt domain generated in the Kth frame and the reverse tilt domain generated in the (K + 1) th are combined to form one region. Similarly, a reverse tilt domain is newly generated in the (K + 2) th frame and the (K + 3) th frame, and these are combined with the reverse tilt domain generated in the (K) th frame and the (K + 1) th frame. As a result, the reverse tilt domain expands in the horizontal direction, and a “horizontal line” is formed in which a horizontal line of black lines is displayed on the pixels Px that should originally display white.

  The liquid crystal molecules m present in the region where the reverse tilt domain is formed support each other so as to maintain a disordered state. The force that the liquid crystal molecules m with disordered alignment support each other becomes stronger as a plurality of reverse tilt domains are combined and the region is expanded. Accordingly, a horizontal line formed by combining a plurality of reverse tilt domains remains for a long period of time.

On the other hand, as shown in FIG. 6B, when the change in the image is not continuous, that is, when the dark pixel Pxb does not move one pixel at a time, the reverse tilt domain disappears in a relatively short time. To do.
In the case shown in FIG. 6B, a reverse tilt domain occurs in the vicinity of the lower side and the left side of the pixel Px1, which is the dark pixel Pxb, in the Kth frame. In the (K + 1) th frame, all the ten pixels Px become the bright pixels Pxw, and the lateral electric field existing near the left side and the lower side of the pixel Px1 disappears. When the lateral electric field disappears, the liquid crystal molecules m in the reverse tilt domain region can be tilted toward the clear viewing direction L. Further, since the liquid crystal molecules m existing around the liquid crystal molecules m constituting the reverse tilt domain are driven by the vertical electric field and tilted toward the clear viewing direction L, the liquid crystal molecules m existing in the reverse tilt domain region are also affected. In response, it gradually tilts toward the clear vision direction L. As a result, the region of the reverse tilt domain is gradually reduced. Similarly, in the (K + 2) th frame and the (K + 3) th frame, all the ten pixels Px become the bright pixels Pxw, and the state in which no lateral electric field exists in the ten pixels Px is continued. The reverse tilt domain gradually shrinks and eventually disappears. As described above, when the reverse tilt domain disappears within a relatively short period of time, it is unlikely that the display defect due to the reverse tilt domain is visually recognized by the user.

In order to suppress the occurrence of display defects that are likely to be visually recognized by the user among the display defects caused by the reverse tilt domain, the occurrence of horizontal lines as shown in FIG. 6A is prevented. It is necessary to do.
A horizontal line is generated when reverse tilt domains generated in a plurality of dark pixels Pxb are combined, and when the plurality of dark pixels Pxb are changed to bright pixels Pxw and white display is to be performed. Therefore, when the image is scrolled pixel by pixel as shown in FIG. 6A, if the reverse tilt domain can be eliminated or reduced at the boundary between the dark pixel Pxb and the bright pixel Pxw, a plurality of reverse tilt domains are combined. Thus, it is possible to prevent the region thus formed from projecting into a region composed of a plurality of bright pixels Pxw that perform white display and forming a horizontal line. More specifically, paying attention to two pixels Px located in the same row, when the dark pixel Pxb and the bright pixel Pxw are adjacent to each other, the occurrence of the reverse tilt domain in the dark pixel Pxb may be suppressed.

Note that the reverse tilt domain occurs in a portion of the dark pixel Pxb close to the side opposite to the clear vision direction L. Therefore, when the bright pixel Pxw is located on the left side when viewed from the dark pixel Pxb among the two pixels Px located in the same row, it is more effective to suppress the occurrence of the reverse tilt domain in the dark pixel Pxb. The generation of horizontal lines can be prevented.
For example, in the case of the example shown in FIG. 6A, the reverse tilt domain includes the pixel Px1 in the Kth frame, the pixel Px2 in the K + 1th frame, the pixel Px3 in the K + 2th frame, and the pixel Px4 in the K + 3th frame. It is possible to suppress the generation of horizontal lines by suppressing the occurrence of.

A method for suppressing the occurrence of the reverse tilt domain will be described with reference to FIG.
FIG. 7 is an enlarged view of a curve VT representing the VT characteristic of the display panel 10 and a part thereof. Note that since the VT characteristic varies depending on the individual display panel 10, in FIG. 7, taking into account the variation in the VT characteristic in the individual display panel 10, the range that the VT curve can take is represented by the curve VT1 (the liquid crystal element 230 of the pixel Px). The graph also expresses the case where the rise of the relative transmittance of the pixel Px is faster than the voltage applied to and the curve VT2 (when the rise is slow).

As described above, since the voltage applied to the liquid crystal element 230 is small in the dark pixel Pxb, the regulating force by the vertical electric field is weak, and the liquid crystal molecules m are in an unstable state. When the dark pixel Pxb and the bright pixel Pxw are adjacent to each other, the horizontal electric field generated between the dark pixel Pxb and the bright pixel Pxw disturbs the orientation of the liquid crystal molecules m located at the boundary between the two pixels Px, and reverse Tilt domain occurs.
Therefore, if the voltage applied to the liquid crystal element 230 of the dark pixel Pxb is increased to a certain extent, the regulating force by the vertical electric field can be increased to stabilize the liquid crystal molecules m of the dark pixel Pxb, and the liquid crystal molecules m Therefore, the occurrence of the reverse tilt domain can be minimized.

However, when the voltage applied to the liquid crystal element 230 of the dark pixel Pxb is increased, the dark pixel Pxb displays a gradation different from the gradation specified by the video signal VIDEO. The problem of deterioration occurs.
Therefore, in the present embodiment, a correction voltage (such that the relative transmittance is 0.1% with respect to the dark pixel Pxb whose relative transmittance corresponding to the gradation specified by the video signal VIDEO is smaller than 0.1%. Correction is performed so as to apply the first voltage (Vc).

  As shown in FIG. 7, the shape of the curve VT indicating the VT characteristic is such that when the voltage applied to the liquid crystal element is less than a certain level (for example, about 1.5 V or less), the relative transmittance of the pixel is also substantially 0. %, While the voltage applied to the liquid crystal element exceeds a certain level, the relative transmittance of the pixel also rises rapidly. Therefore, by setting the correction voltage Vc to a voltage corresponding to the relative transmittance of the pixel of 0.1%, the value of the correction voltage Vc can be set to a sufficiently large value. For example, as shown in FIG. 7, when correction is performed on a dark pixel Pxb for which a gradation corresponding to the black display voltage Vbk (relative transmittance 0%) is specified, the relative transmittance of the dark pixel Pxb is corrected. The voltage changes from 0% before the correction to 0.1% after the correction, and the amount of change is slight, whereas the voltage applied to the liquid crystal element 230 is changed from 0V before the correction to 1.1V to 1 after the correction. It changes greatly to about 3V. That is, according to the correction of the present embodiment, since a large voltage can be applied to the liquid crystal element 230 while minimizing the luminance change of the dark pixel Pxb, the occurrence of the reverse tilt domain can be effectively suppressed. .

Even when correction is performed on the dark pixel Pxb, when a large voltage (for example, a voltage corresponding to the white display voltage Vwt) is applied to the liquid crystal element 230 of the bright pixel Pxw adjacent to the dark pixel Pxb. In this case, since a large lateral electric field is generated between these two pixels, the occurrence of the reverse tilt domain may not be completely prevented.
For example, as shown in FIG. 8A, when correction is performed on the dark pixel Pxb (pixels Px3, Px5, and Px6) adjacent to the bright pixel Pxw, the pixel Px that has undergone the correction is also reversed. A tilt domain may occur.

  However, the reverse tilt domain generated in the corrected pixel Px can be suppressed to a small scale as compared with the reverse tilt domain generated when correction is not performed as shown in FIG. 5A, for example. That is, by performing the correction, it is possible to reduce the possibility that the reverse tilt domain occurs, and even if the reverse tilt domain occurs, the influence can be minimized. As shown in FIG. 8B, since the correction voltage Vc is applied to the pixel electrode 231 of the dark pixel Pxb (pixel Px3), a vertical electric field is generated in the pixel Px3 and the bright pixel Pxw adjacent to the pixel Px3. This is because the magnitude of the transverse electric field generated between (Px2) can be kept small.

Further, since the reverse tilt domain is small in the corrected pixel Px, it is unlikely that the reverse tilt domain will be combined with the reverse tilt domain generated in the other pixel Px, and the possibility of developing into a horizontal line is low.
FIG. 9 is a diagram illustrating a change after the occurrence of the reverse tilt domain generated in the corrected pixel Px. The reverse tilt domain generated in the dark pixels Px1 and Px2 corrected in the Kth frame is not combined with the reverse tilt domain generated in the pixels Px3 and Px4 in the K + 1th frame, and the area is reduced. Then, the reverse tilt domain generated in the pixels Px1 and Px2 is further reduced in the K + 2 frame and the K + 3 frame, and finally disappears. As described above, according to the correction of the present embodiment, even if a reverse tilt domain occurs, the scale thereof can be suppressed to be small, so that it is possible to prevent the reverse tilt domain from being combined to form a horizontal line.

FIG. 10 is a block diagram showing a configuration of the video processing circuit 70. The video processing circuit 70 generates an analog data signal Vid after correcting the video signal VIDEO based on the correction voltage Vc.
The video processing circuit 70 includes a γ correction unit 71 that outputs the first signal V1 based on the video signal VIDEO, a delay circuit 72 that outputs the second signal V2 based on the first signal V1, the first signal V1 and the first signal V1. A determination unit 73 that outputs a determination value Q based on the two signals V2, a correction unit 74 that outputs an output signal Vout based on the determination value Q and the first signal V1, and a data signal Vid based on the output signal Vout. And a D / A conversion unit 75 for converting the data into a D / A conversion unit.

When the video signal VIDEO is input from the host device, the γ correction unit 71 performs gamma correction on the video signal VIDEO by referring to a look-up table indicating the VT characteristics of the display panel 10, and each of the video signals specified by the video signal VIDEO is designated. A voltage value corresponding to the gradation of the pixel is output as the first signal V1. Note that the look-up table indicating the VT characteristics is preset in the γ correction unit 71, for example.
The delay circuit 72 delays the first signal V1 supplied from the γ correction unit 71 by one pixel (one period of the dot clock signal Dclk) according to a control signal such as the dot clock signal Dclk supplied from the scanning control circuit 60. The second signal V2 is output.

  In the determination unit 73, the value indicated by the first signal V1 supplied from the γ correction unit 71 is less than the correction voltage Vc, and the value indicated by the second signal V2 supplied from the delay circuit 72 is optically saturated. It is determined that the voltage is equal to or higher than Vsat. Next, when the determination condition is satisfied, the determination unit 73 sets a value indicating that the determination condition is satisfied, for example “1”, to the determination value Q, and when the determination condition is not satisfied, the determination value 73 A value indicating that the determination condition is not satisfied is set to Q, for example, “0”, and the determination value Q is output. Note that the values of the optical saturation voltage Vsat and the correction voltage Vc are set in advance in the determination unit 73 or provided from a higher-level device, for example.

When the determination value Q input from the determination unit 73 is “1”, the correction unit 74 sets and outputs the output signal Vout equal to the correction voltage Vc, while the determination value Q is “0”. In this case, the output signal Vout is set to a value equal to the first signal V1 and output.
The D / A converter 75 converts the output signal Vout, which is a digital signal, into a data signal Vid, which is an analog signal, and then outputs the data signal Vid to the data line driving circuit 32.

FIG. 11 shows the relationship between the video signal VIDEO input to the video processing circuit 70 and the data signal Vid output from the video processing circuit 70. Here, as shown in FIG. 11A, the video signal VIDEO defines the gradation of the pixel Px in the i-th row and j-th column to a value corresponding to the white display voltage Vwt, and the i-th row in the (j + 1) th row. Assume that the gradation of the pixels Px in the column is defined to be a value corresponding to the black display voltage Vbk (here, j is a natural number satisfying 1 ≦ j ≦ N−1).
In this case, as shown in FIG. 11B, the video processing circuit 70 corrects the value indicated by the video signal VIDEO, and then each value of the data voltages VD [1] to VD [N]. A data signal Vid for designating is output. Specifically, the video processing circuit 70 sets a value corresponding to the data voltage VD [j + 1] that defines the gray level of the pixel Px in the i-th row and the (j + 1) th column in the data signal Vid to a value equal to the correction voltage Vc. Set to. On the other hand, the video processing circuit 70 sets a value corresponding to the data voltage VD [j] that defines the gradation of the pixel Px other than the j + 1th column of the pixel Px in the i-th row among the data signal Vid of the video signal VIDEO. Each is set to a value indicated by a voltage corresponding to the specified gradation. The data voltages VD [1] to VD [N] whose values are specified by the data signal Vid are supplied to each pixel Px, so that the bright pixel Pxw in the i-th row and j-th column and the i-th row It is possible to suppress the occurrence of a reverse tilt domain between the dark pixels Pxb in the j + 1 column.

As described above, in the liquid crystal device 1 according to the present embodiment, correction is performed so that the correction voltage Vc is applied to the dark pixel Pxb so that the relative transmittance is 0.1%. When the voltage applied to the liquid crystal element 230 is equal to or less than a certain level, the VT characteristic of the display panel 10 changes while the relative transmittance of the pixel Px is kept substantially 0%. Therefore, by setting the correction voltage Vc to a voltage that makes the relative transmittance of the pixel 0.1%, a large voltage is applied to the liquid crystal element 230 while minimizing the change in the relative transmittance of the pixel Px due to the correction. Can be applied.
That is, the liquid crystal device 1 according to the present embodiment effectively suppresses the occurrence of the reverse tilt domain while minimizing the possibility of the user visually recognizing the luminance change by minimizing the luminance change due to the correction. Has the advantage of becoming possible.

In the liquid crystal device 1 according to the present embodiment, the correction voltage Vc is determined based on the relative transmittance of the pixel Px. That is, the correction voltage Vc applied to the liquid crystal element 230 is determined so that the relative transmittance of the pixel Px becomes a certain constant (0.1%).
The VT characteristic indicating the relationship between the relative transmittance of the pixel Px and the voltage applied to the liquid crystal element 230 differs depending on the individual display panel 10. If the correction voltage is set to a certain value, even if the correction voltage is applied to the liquid crystal elements of different display panels, the relative transmittance of the pixels between the display panels is The display quality does not become constant, and the display quality varies for each display panel. In this case, in some display panels, there is a possibility that the luminance change due to the correction becomes so large that it is visually recognized by the user.
On the other hand, as in the liquid crystal device 1 according to the present embodiment, the value of the correction voltage Vc is determined on the basis of the relative transmittance of the pixel Px, so that the VT characteristics vary among the individual display panels 10. Even in this case, it is possible to keep the luminance change when the correction is performed within a certain range. That is, the correction according to the present embodiment can equalize the influence on the luminance change when the correction is performed for each display panel 10, so that the production process including the inspection of the liquid crystal device 1 can be simplified. Has the advantage of becoming.

  Further, in the liquid crystal device 1 according to the present embodiment, when the bright pixel Pxw is adjacent to the opposite side to the clear vision direction L when viewed from the dark pixel Pxb, the dark pixel Pxw is adjacent to the dark pixel Pxb. Correction is performed on the pixel Pxb. The reverse tilt domain often occurs when the bright pixel Pxw is adjacent to the side opposite to the clear vision direction L when viewed from the dark pixel Pxb. Therefore, the reverse tilt domain is corrected by correcting the dark pixel Pxb. Generation of a domain can be effectively suppressed, and even if a reverse tilt domain occurs, it can be prevented from expanding and developing into a horizontal line.

  Further, in the liquid crystal device 1 according to the present embodiment, when the bright pixel Pxw is adjacent to the opposite side to the clear vision direction L when viewed from the dark pixel Pxb, the dark pixel Pxw is adjacent to the dark pixel Pxb. Since the correction is limited to the pixel Pxb, the number of pixels to be corrected can be minimized as compared with the case where the correction is performed on all the dark pixels Pxb adjacent to the bright pixel Pxw. Therefore, the liquid crystal device 1 according to the present embodiment has an advantage that even when the image has light and shade, the outline portion is prevented from being blurred and a clear image can be displayed, and the display caused by the reverse tilt domain is provided. There is an advantage that the above problem can be effectively suppressed.

<B: Second Embodiment>
FIG. 12 is a block diagram of the video processing circuit 70a according to the second embodiment. The liquid crystal device of the second embodiment is configured in the same manner as the liquid crystal device 1 of the first embodiment, except that a video processing circuit 70a is provided instead of the video processing circuit 70.

As shown in FIG. 12, the video processing circuit 70a is configured in the same manner as the video processing circuit 70 except that the video processing circuit 70a includes a correction unit 74a and a counter 76. When the bright pixel Pxw is adjacent to the dark pixel Pxb on the side opposite to the bright vision direction L, the video processing circuit 70a includes the dark pixel Pxb and continues to the clear vision direction L side. A data signal Vid that corrects each of the pixels Px (a natural number of 1 or more) is output.
Hereinafter, a specific configuration of the video processing circuit 70a will be described.

  The counter 76 generates a count value Qc based on the determination value Q supplied from the determination unit 73 and the dot clock signal Dclk supplied from the scanning control circuit 60, and outputs this to the correction unit 74a. Specifically, the counter 77 resets the count value Qc to “0” at the timing when the determination value Q becomes “1”. Further, when the determination value Q is “0”, the counter 77 counts up the count value Qc by 1 every interval corresponding to one period in the dot clock signal Dclk.

  The correction unit 74a generates an output signal Vout based on the first signal V1 supplied from the γ correction unit 71 and the count value Qc supplied from the counter 76, and outputs the output signal Vout to the D / A conversion unit 75. . Specifically, the correction unit 74a first determines that the count value Qc is a value less than the predetermined number D, and the first signal V1 is a value less than the correction voltage Vc. Next, the correction unit 74a sets the value of the output signal Vout to a value equal to the correction voltage Vc when the determination condition is affirmed, and sets the value of the output signal Vout when the determination condition is negative. The output signal Vout is output to the D / A converter 75 after being set to a value equal to the first signal V1.

FIG. 13 shows the relationship between the video signal VIDEO input to the video processing circuit 70a and the data signal Vid output from the video processing circuit 70a. FIG. 13 shows a case where the predetermined number D is set to “3”.
As shown in FIG. 13A, the video signal VIDEO has three video signals of i-th row, j + 1 column to i-th row, j + 3 column (where j is a natural number satisfying 1 ≦ j ≦ N−3). The gradation of the pixel Px is defined as a value corresponding to the black display voltage Vbk, and the gradation of the pixel Px in the i-th row and j-th column is defined as a value corresponding to the white display voltage Vwt.

In this case, as shown in FIG. 13B, the video processing circuit 70a includes data defining the gradation of the three pixels Px in the i-th row, j + 1-th column to the i-th row, j + 3-th column, among the data signal Vid. Values corresponding to the voltages VD [j + 1] to VD [j + 3] are respectively set to values equal to the correction voltage Vc. On the other hand, the video processing circuit 70a defines the gradation of the pixels Px other than the three pixels Px in the i-th row j + 1 column to the i-th row j + 3 column in the i-th row pixel Px in the data signal Vid. A value corresponding to the data voltage VD [j] is set to a value indicated by a voltage corresponding to the gradation specified by the video signal VIDEO.
Thereby, it is possible to suppress the occurrence of the reverse tilt domain between the bright pixel Pxw in the i-th row and j-th column and the dark pixel Pxb in the i-th row and j + 1-th column.

FIG. 14A is a diagram for explaining the occurrence of a reverse tilt domain and subsequent changes when the video signal VIDEO is corrected by the video processing circuit 70a according to the second embodiment.
In the example shown in FIG. 14A, in the K-th frame, reverse is performed between the plurality of bright pixels Pxw in the (i + 1) th row and the pixels Px2 to Px6 in the i-th row and between the pixels Px2 and Px1. There is a tilt domain. In the Kth frame, the dark pixel Pxb (black display) located in the pixels Px2 to Px6 is scrolled to the right by one pixel per frame after the Kth frame. In the example shown in this figure, the predetermined number D is set to “3”, and correction is performed for three dark pixels Pxb adjacent to the bright pixel Pxw.

As shown in FIG. 14 (A), in the Kth frame, correction is performed for the pixels Px2 to Px4. Therefore, the reverse tilt domain generated in these three pixels Px is the uncorrected pixels Px5 and Px6. Smaller than the reverse tilt domain that occurs. In the (K + 1) th frame, since the pixel Px2 becomes the bright pixel Pxw and the pixels Px3 to Px5 are corrected, the reverse tilt domain existing in these four pixels Px reduces the area. Thereafter, the reverse tilt domain existing in these pixels Px is further reduced, and the reverse tilt domain disappears in the pixel Px2 in the (K + 3) th frame.
As described above, the reverse tilt domain generated in the dark pixel Pxb gradually increases in a period corresponding to three frames immediately before the dark pixel Pxb changes to the bright pixel Pxw, that is, in a period in which the dark pixel Pxb is corrected. To reduce the area. Therefore, when the dark pixel Pxb changes to the bright pixel Pxw, the reverse tilt domain is sufficiently small and then disappears quickly thereafter.

On the other hand, FIG. 14B shows a case where the predetermined number D is set to “1” and only one pixel is corrected for comparison.
For example, the pixel Px3 that is the dark pixel Pxb in the Kth frame becomes the bright pixel Pxw in the K + 2th frame after being corrected in the K + 1th frame. In this case, the reverse tilt domain generated in the pixel Px3 in the Kth frame reduces the area because the pixel Px is corrected in the (K + 1) th frame. However, when the pixel Px3 becomes the bright pixel Pxw in the (K + 2) th frame, the reverse tilt domain remains not sufficiently small. As described above, when only one pixel is corrected, the reverse tilt domain remains on the bright pixel Pxw while having a relatively large region.

Thus, in the liquid crystal device according to the second embodiment, when the bright pixel Pxw is adjacent to the dark pixel Pxb on the opposite side to the clear vision direction L, the predetermined number D of pixels Px including the dark pixel Pxb is used. Therefore, the reverse tilt domain can be more effectively suppressed.
Further, the liquid crystal device according to the present embodiment does not correct all the dark pixels Pxb adjacent to the bright pixel Pxw, but the bright pixel Pxw is adjacent to the dark pixel Pxb opposite to the clear viewing direction L. In this case, the correction is performed with the correction voltage Vc so that the relative transmittance of the pixel is 0.1%. Therefore, even when the image has light and shade, the outline portion is prevented from being blurred and a clear image can be obtained. It has the advantage that it can be displayed.

<C: Third Embodiment>
FIG. 15 is a block diagram of a video processing circuit 70b according to the third embodiment. The liquid crystal device according to the third embodiment includes a video processing circuit 70b instead of the video processing circuit 70, and includes a liquid crystal having a clear viewing direction L toward the upper left when viewed from a direction perpendicular to the display panel. The configuration is the same as that of the liquid crystal device 1 of the embodiment.
In the liquid crystal according to the third embodiment, the clear vision direction L is a direction toward the upper left when viewed from the direction perpendicular to the display panel. Therefore, the video processing circuit 70b performs two pixel Px located in the same row. When the bright pixel Pxw is adjacent to the right side of the dark pixel Pxb, a data signal Vid that corrects the dark pixel Pxb is output.

A video processing circuit 70b shown in FIG. 15 is configured in the same manner as the video processing circuit 70 except that it includes a determination unit 73b instead of the determination unit 73 and a correction unit 74b instead of the correction unit 74. In the video processing circuit 70b, the first signal V1 output from the γ correction unit 71 is supplied to the delay circuit 72 and the determination unit 73b. The second signal V2 output from the delay circuit 72 is supplied to the determination unit 73b and the correction unit 74b.
The determination unit 73b corrects the value indicated by the first signal V1 supplied from the γ correction unit 71 to be equal to or higher than the optical saturation voltage Vsat and the value indicated by the second signal V2 supplied from the delay circuit 72. It is determined that the voltage is less than Vc. Next, when the determination condition is satisfied, the determination unit 73b sets a value indicating that the determination condition is satisfied, such as “1”, for example, to the determination value Q2, and when the determination condition is not satisfied, A value indicating that the determination condition is not satisfied is set in Q2, for example, “0”, and the determination value Q2 is output. When the determination value Q2 input from the determination unit 73b is “1”, the correction unit 74b sets and outputs the output signal Vout equal to the correction voltage Vc, while the determination value Q2 is “0”. In this case, the output signal Vout is set to a value equal to the second signal V2 and output.

FIG. 16 shows the relationship between the data signal Vid output from the video processing circuit 70b and the video signal VIDEO. The video processing circuit 70b corrects the value indicated by the video signal VIDEO shown in FIG. 16A, and then data voltages VD [1] to VD [N] as shown in FIG. 16B. A data signal Vid for designating each value is generated. Specifically, the video processing circuit 70b sets the value corresponding to the data voltage VD [j−1] that defines the gradation of the pixel Px in the i-th row and the (j−1) th column in the data signal Vid as the correction voltage. While the value is set equal to Vc, the video signal VIDEO defines a value corresponding to the data voltage VD [j] that defines the gradation of the pixel Px other than the j−1 column among the pixels Px in the i-th row. Each is set to a value indicated by a voltage corresponding to a gradation (here, j is a natural number satisfying 2 ≦ j ≦ N).
Thereby, it is possible to suppress the occurrence of a reverse tilt domain between the bright pixel Pxw in the i-th row and the j-th column and the dark pixel Pxb in the i-th row and the (j−1) -th column on the left side of the bright pixel Pxw. It becomes.

<D: Fourth Embodiment>
FIG. 17 is a block diagram of a video processing circuit 70c according to the fourth embodiment. The liquid crystal device of the fourth embodiment is configured in the same manner as the liquid crystal device 1 of the first embodiment, except that a video processing circuit 70c is provided instead of the video processing circuit 70.

As shown in FIG. 17, the video processing circuit 70c according to the fourth embodiment is configured in the same manner as the video processing circuit 70 except that it includes a determination unit 73c, a correction unit 74c, a counter 76c, and a second delay circuit 77. The
The correction unit 74c is configured in the same manner as the correction unit 74a of the video processing circuit 70a according to the second embodiment except that the third signal V3 is supplied instead of the first signal V1. The counter 76c is configured in the same manner as the counter 76 of the video processing circuit 70a according to the second embodiment, except that the determination value Qj is supplied instead of the determination value Q.
When the bright pixel Pxw is adjacent to the dark pixel Pxb on the bright vision direction L side of the plurality of pixels Px located in the same row, the video processing circuit 70c is opposite to the bright vision direction L including the dark pixel Pxb. Correction is performed for a predetermined number D of pixels Px that are continuous on the side, and when the dark pixel Pxb is adjacent to the bright vision direction L side of the bright pixel Pxw, the bright pixel Pxb including the dark pixel Pxb A data signal Vid for correction is output to a predetermined number D of consecutive pixels Px.

The determination unit 73c counters the determination value Qj based on the value indicated by the first signal V1 supplied from the γ correction unit 71, the value indicated by the second signal V2 supplied from the delay circuit 72, and the dot clock signal Dclk. Output to 77.
Here, the value indicated by the first signal V1 is equal to or higher than the optical saturation voltage Vsat and the value indicated by the second signal V2 is less than the correction voltage Vc as a “first condition”. Further, the “second condition” is that the value indicated by the first signal V1 is less than the correction voltage Vc and the value indicated by the second signal V2 is equal to or higher than the optical saturation voltage Vsat. The first condition is a condition indicating that the bright pixel Pxw is adjacent to the right side of the dark pixel Pxb, and the second condition is a condition indicating that the bright pixel Pxw is adjacent to the left side of the dark pixel Pxb.

When the first condition is satisfied, the determination unit 73c sets and outputs a value indicating that the determination condition is satisfied, for example, “1” as the determination value Qj. On the other hand, when the second condition is satisfied, the determination unit 73c sets a value “1” indicating that the determination condition is satisfied as the determination value Qj, and then delays by a period corresponding to the predetermined number D of the dot clock signals Dclk. And output it.
When neither the first condition nor the second condition is satisfied, a value indicating that the determination condition is not satisfied, for example, “0” is output as the determination value Qj. However, when “0” is output as the determination value Qj and “1” is output as the determination value Qj, “1” is output as the determination value Qj. That is, when the second condition is satisfied before a predetermined number D of dot clock signals Dclk, “1” is output as the determination value Qj.
The second delay circuit 77 delays the first signal V1 input from the γ correction unit 71 by a period corresponding to a predetermined number D of the dot clock signals Dclk supplied from the scanning control circuit 60, and outputs a third signal. V3 is output. The predetermined number D is set in advance in the second delay circuit 76 or the host device, for example.

FIG. 18 shows the relationship between the data signal Vid output from the video processing circuit 70c and the video signal VIDEO. The video processing circuit 70c corrects the value indicated by the video signal VIDEO shown in FIG. 18A, and then data voltages VD [1] to VD [N as shown in FIG. 18B. ] To generate a data signal Vid that designates each value. Specifically, the video processing circuit 70c includes the u-th column to the u-1 column (u is a natural number satisfying 4 ≦ u ≦ N) and the v + 1-th column of the data signal Vid. Data voltages VD [u−3] to VD [u−1] and VD [v + 1] to VD defining the gradation of six pixels Px in the v + 3 column (v is a natural number satisfying 1 ≦ v ≦ N−3). A value corresponding to [v + 3] is set to a value equal to the correction voltage Vc. On the other hand, the video processing circuit 70c has a value corresponding to the data voltage VD [j] that defines the gradation of the pixels Px other than the six pixels among the N pixels Px in the i-th row in the data signal Vid. Are respectively set to values indicated by voltages corresponding to gradations defined by the video signal VIDEO.
Accordingly, in the i-th row, the reverse is performed between the light pixel Pxw in the u-th column and the dark pixel Pxb in the u-th column, and between the light pixel Pxw in the v-th column and the dark pixel Pxb in the v + 1-th column. It is possible to suppress the occurrence of the tilt domain.

FIG. 19 is a diagram for explaining the occurrence of a reverse tilt domain and subsequent changes when the video signal VIDEO is corrected by the video processing circuit 70c according to the fourth embodiment. FIGS. 19A and 19B illustrate a case where there are a plurality of bright pixels Pxw in the (i + 1) th row and four dark pixels Pxb in the ith row. Note that the dark pixel Pxb existing in the i-th row is scrolled to the left by one pixel per frame.
FIG. 19A shows a case where correction is performed on two dark pixels Pxb in contact with the bright pixel Pxw among the four dark pixels Pxb in the i-th row (that is, the predetermined number D is “1”). And). In this case, a reverse tilt domain occurs in the lower side of the pixels Px3 to Px5 in the Kth frame, but since the correction is performed on the pixel Px5, the region of the reverse tilt domain in the pixel Px5 is small. The reverse tilt domain generated at Px5 is reduced after the pixel Px5 is changed to the bright pixel Pxw in the (K + 1) th frame and disappears in the (K + 3) th frame.
On the other hand, in FIG. 19B, among the four dark pixels Pxb in the i-th row, only the leftmost pixel Px2 is corrected, and the rightmost pixel Px5 is not corrected. In this case, the reverse tilt domains generated on the upper sides of the pixels Px3 to Px5 in the Kth frame are not reduced, but are coupled to each other and a horizontal line is generated.

  Thus, when the bright pixel Pxw is adjacent to the right side of the dark pixel Pxb (when corresponding to the first condition), and when the bright pixel Pxw is adjacent to the left side of the dark pixel Pxb (when corresponding to the second condition). By correcting the dark pixel Pxb, the bright pixel Pxw is adjacent to the lower side of the plurality of dark pixels Pxb as shown in FIG. 19, and the plurality of dark pixels Pxb are one pixel on the left side. It is possible to suppress the generation of horizontal lines that occur when scrolling.

  Note that the video processing circuit 70c described above is positioned at the right end and the left end among a plurality of continuously existing dark pixels Pxb by considering both when the first condition is satisfied and when the second condition is satisfied. The predetermined number D of dark pixels Pxb are corrected. However, the correction may be performed in consideration of only one of the first condition and the second condition. When only the first condition is considered, correction is performed only on a predetermined number D of dark pixels Pxb located at the right end among a plurality of continuously existing dark pixels Pxb. When only the second condition is considered, correction is performed only on a predetermined number D of dark pixels Pxb located at the left end among a plurality of dark pixels Pxb that exist continuously.

<E: Modification>
As mentioned above, although embodiment of this invention was described, you may add the deformation | transformation described below with respect to this embodiment.
(1) Modification 1
In the first to fourth embodiments described above, the clear vision direction L is a direction toward the upper right or a direction toward the upper left when viewed from the direction perpendicular to the display panel. However, the clear vision direction L is a direction other than these directions. It may be. Whatever the clear vision direction L is, pay attention to the component parallel to the scanning line 21 in the clear vision direction L, and when the component faces the right side, the bright pixel Pxw is on the left side of the dark pixel Pxb. When the pixel is adjacent to the dark pixel Pxb, the dark pixel Pxb is corrected when the dark pixel Pxb is adjacent to the right side of the dark pixel Pxb. Thus, the occurrence of the reverse tilt domain can be effectively suppressed.

(2) Modification 2
In the above-described embodiment, the voltage at which the relative transmittance of the pixel Px is 0.1% is used as the correction voltage Vc. However, the correction voltage Vc is set so that the relative transmittance of the pixel is a value other than 0.1%. May be determined. For example, the correction voltage Vc may be determined so that the relative transmittance of the pixel is greater than 0% and smaller than 0.1%. In this case, the amount of change in luminance due to correction can be made smaller, and the influence on display quality can be made smaller. On the other hand, the correction voltage Vc may be determined so that the relative transmittance of the pixel Px is larger than 0.1%. In this case, generation of the reverse tilt domain can be more effectively suppressed. The correction voltage Vc is preferably set to a voltage smaller than the voltage at which the VT curve rises rapidly in consideration of the VT characteristics of the display panel 10.

(3) Modification 3
In the embodiment described above, when the bright pixel Pxw and the dark pixel Pxb to which a voltage equal to or higher than the optical saturation voltage Vsat at which the relative transmittance of the pixel Px is 90% are applied are adjacent to the dark pixel Pxb, Although correction has been performed, when a pixel Px to which a voltage is applied so that the relative transmittance of the pixel is smaller than 90% is adjacent to the dark pixel Pxb, the dark pixel Pxb is corrected. You may make it do. In this case, it is possible to further reduce the possibility of occurrence of the reverse tilt domain.

(4) Modification 4
In the embodiment described above, the liquid crystal element 230 is in the normally black mode, but may be in a normally white mode. In the normally white mode, as shown in FIG. 20, when the voltage applied to the liquid crystal element is the minimum value (0V), the relative transmittance of the pixel is 100%, and when the voltage is the maximum value (for example, 5V). The relative transmittance of the pixel is set to 0%. Then, the correction voltage Vc2 may be determined so that the relative transmittance of the pixel is smaller than a voltage that suddenly falls from 100%. Further, the correction voltage Vc2 may be determined so that the relative transmittance of the pixel becomes a certain value. For example, a voltage corresponding to a pixel having a relative transmittance of 99.9% may be used as the correction voltage Vc2.
In the correction shown in FIG. 20, the bright pixel Pxw to which a voltage lower than the correction voltage Vc2 is applied and the dark pixel Pxb to which a voltage equal to or higher than the voltage Vth at which the relative transmittance is 10% are adjacent to each other. In this case, the process may be performed on the bright pixel Pxw.

(5) Modification 5
In the above-described embodiment, the VA liquid crystal 232 is used, but a TN liquid crystal may be used.
When the liquid crystal is the TN system, the clear viewing direction of the liquid crystal and the location where the reverse tilt domain occurs are different from the VA system in the first to fourth embodiments described above. For example, a case where a normally white mode liquid crystal element is employed is assumed. At this time, as shown in FIG. 21, the counter substrate is rubbed from the right side to the left side in the drawing along the scanning line direction, and the element substrate is rubbed from the bottom side to the upper side in the drawing along the data line direction. In this case, the clear viewing direction L of the liquid crystal is the direction from the lower left α to the upper right β in the figure, and the reverse tilt domain generation region occurs in the clear viewing direction side region in the bright pixel Pxw. Therefore, the occurrence of the reverse tilt domain can be effectively suppressed by correcting the bright pixel Pxw adjacent to the opposite side to the clear vision direction when viewed from the dark pixel Pxb.

<F: Application example>
Next, an electronic apparatus using the liquid crystal device 1 according to each of the above aspects will be described. 22 to 24 show forms of electronic devices that employ the liquid crystal device 1 as a display device.
FIG. 22 is a perspective view showing a configuration of a mobile personal computer employing the liquid crystal device 1. The personal computer 2000 includes a liquid crystal device 1 that displays various images, and a main body 2010 on which a power switch 2001 and a keyboard 2002 are installed.

  FIG. 23 is a perspective view showing a configuration of a mobile phone to which the liquid crystal device 1 is applied. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the liquid crystal device 1 that displays various images. By operating the scroll button 3002, the screen displayed on the liquid crystal device 1 is scrolled.

FIG. 24 is a schematic view illustrating a projection display device (projector) 4000 as an electronic apparatus. The projection type display device 4000 includes the illumination device 4020, the separation optical system 4040, the three display panels 10 (10r, 10g, 10b) according to the above embodiments, the projection optical system 4060, and a control circuit (not shown). .
The control circuit includes a scanning control circuit 60 and three video processing circuits 70 (70r, 70g, 70b). The three video processing circuits 70 are respectively based on video signals VIDEO (VIDEO_r, VIDEO_g, VIDEO_b) representing red, green, and blue supplied from an external host device, and data signals Vid (Vid_r) corresponding to red, green, and blue. , Vid_g, Vid_b).
A common signal is supplied to each display panel 10 from a control circuit. Each display panel 10 is supplied with data signals Vid corresponding to red, green, and blue from the three video processing circuits 70, respectively. As described above, the control circuit generates various signals while synchronizing the image display among the display panels 10.
The separation optical system 4040 separates the illumination light emitted from the illumination device 4020 into a plurality of single color lights (red light, green light, blue light) and irradiates each display panel 10. Specifically, the red light r of the illumination light enters the display panel 10r after being reflected by the dichroic mirror 4041 and the mirror 4042. The green light g transmitted through the dichroic mirror 4041 is reflected by the dichroic mirror 4043 and enters the display panel 10g. The blue light b transmitted through the dichroic mirror 4043 is incident on the display panel 10b via the mirror 4044 and the mirror 4045.
Each display panel 10 is used as a light modulator (light valve) that modulates incident light to form an image. The display panel 10r modulates the red light r coming from the mirror 4042 to form a red image. Similarly, the display panel 10g forms a green image, and the display panel 10b forms a blue image. The projection optical system 4060 projects the emitted light from each display panel 10 onto the display surface 4080. The projection optical system 4060 includes a dichroic prism 4061 that synthesizes light emitted from each display panel 10 (red light, green light, and blue light), and a projection lens 4062 that projects light emitted from the dichroic prism 4061 onto the display surface 4080. It is comprised including. Therefore, a color image is displayed on the display surface 4080.

  Note that electronic devices to which the liquid crystal device according to the present invention is applied include, in addition to the devices illustrated in FIGS. 22 to 24, personal digital assistants (PDAs), digital still cameras, televisions, video cameras, cars Examples include navigation devices, pagers, electronic notebooks, electronic papers, calculators, word processors, workstations, videophones, POS terminals, printers, scanners, copiers, video players, devices equipped with touch panels, and the like.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal device, 10 ... Display panel, 20 ... Display area, 21 ... Scan line, 22 ... Data line, 31 ... Scan line drive circuit, 32 ... Data line drive circuit, 50 ... Control circuit, 60 ... Scan control circuit, 70: Video processing circuit, 230: Liquid crystal element, 232: Liquid crystal, L: Clear vision direction, Px: Pixel, Pxb: Dark pixel, Pxw: Bright pixel, Q: Determination value, VD: Data voltage, VIDEO ... Video signal, Vid ... data signal, Vc ... correction voltage (first voltage), Vsat ... optical saturation voltage (second voltage), Vbk ... black display voltage, Vwt ... white display voltage, m ... liquid crystal molecule.

Claims (6)

A plurality of scan lines;
Multiple data lines,
A plurality of pixels provided corresponding to intersections of the plurality of scanning lines and the plurality of scanning lines;
A video processing circuit that generates a data signal that defines the transmittance of each of the plurality of pixels based on the video signal so as to obtain a gradation to be displayed;
A data line driving circuit for supplying the data signal to the plurality of data lines;
A scanning line driving circuit for driving the plurality of scanning lines,
When the direction in which the liquid crystal molecules are displaced based on the data signal when viewed from the direction perpendicular to the display surface is the clear vision direction,
In the video processing circuit, an applied voltage applied to a liquid crystal of one pixel among the plurality of pixels is smaller than a first voltage, and a pixel positioned in a direction opposite to the clear viewing direction with respect to the one pixel is selected. When the applied voltage applied to the liquid crystal is greater than or equal to a second voltage greater than the first voltage, the data signal is corrected by correcting the voltage applied to the liquid crystal of the one pixel to be the first voltage. A liquid crystal display device characterized by being produced. The transmittance of the pixel corresponding to the maximum value of the data signal is 100%,
When the transmittance of the pixel corresponding to the minimum value of the data signal is 0%,
The first voltage is a voltage that causes the transmittance of the pixel to be greater than 0% and 0.1% or less.
The liquid crystal display device according to claim 1. When the pixel adjacent to the first pixel in the direction opposite to the clear vision direction is the second pixel,
The video processing circuit includes:
Gamma correction means for generating a first signal by performing gamma correction on the video signal;
Delay means for delaying the first signal corresponding to the first pixel to generate a second signal corresponding to the second pixel;
Determination means for determining whether a value indicated by the first signal is smaller than the first voltage and a value indicated by the second signal is equal to or higher than a second voltage;
When the determination result of the determination unit indicates affirmative, a correction unit that generates the data signal by correcting the first signal as the first voltage;
Comprising
The liquid crystal display device according to claim 1. When the data signal has a value smaller than the first voltage for each of a predetermined number of pixels positioned on the clear vision direction side with respect to the one pixel, the video processing circuit Correcting the first voltage to generate the data signal;
It is characterized by
The liquid crystal display device according to claim 1.   An electronic apparatus comprising the liquid crystal display device according to claim 1. Liquid crystal containing liquid crystal molecules, a plurality of scanning lines, a plurality of data lines, a plurality of pixels provided corresponding to intersections of the plurality of scanning lines and the plurality of scanning lines, and the plurality of data lines A data signal generation method for generating the data signal to be supplied to a liquid crystal display device comprising: a data line driving circuit for supplying a data signal to the liquid crystal display device; and a scanning line driving circuit for driving the plurality of scanning lines,
When the direction in which the liquid crystal molecules are displaced based on the data signal when viewed from the direction perpendicular to the display surface is the clear vision direction,
The applied voltage applied to the liquid crystal of one pixel among the plurality of pixels is smaller than the first voltage and applied to the liquid crystal of the pixel located in the opposite direction to the clear vision direction with respect to the one pixel. Determining whether the voltage is greater than or equal to a second voltage greater than the first voltage;
When the determination result is affirmative, the data signal is generated by correcting the voltage applied to the liquid crystal of the one pixel to be the first voltage,
When the determination result is negative, a data signal that specifies a voltage applied to the liquid crystal of the one pixel so as to have a gradation indicated by the video signal is generated.
A data signal generation method characterized by the above.

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