JP2008039868A - Liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem in a three-plate projection type liquid crystal display device that when the response characteristics of three plate liquid crystal display panels are different, edges are colored when a pattern which is originally achromatic is displayed as a moving image, and the display quality of a moving image deteriorates. <P>SOLUTION: An interpolation processing part 17 calculates a correction factor K(x, y) according to two dimensional coordinates of display pixels by interpolation processing based on m x n pieces of dynamic image correction factor data read from an in-plane distribution correction factor table 16. A multiplier 15 multiplies a difference ΔS between a current frame signal Sn and a previous frame signal Sn-1 by the correction factor, adding an obtained difference signal ΔS' to the current frame signal Sn by an adder 18 to obtain a final corrected signal Sn'. Thus, even when liquid crystal cell thickness tendency of each color panel in the three-plate projection type liquid crystal display varies, the image quality deterioration occurring partially in the plane is improved by optimizing the dynamic image correction factor data representatives. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a three-plate active matrix liquid crystal display device suitable for a projection type liquid crystal display or the like.

  In recent years, in parallel with technological progress of computers, communications, broadcasting, information recording media, etc., there is an increasing demand for displays that display such video information on a large screen and with high definition. In order to realize this, an active matrix liquid crystal display device has been put into practical use. However, in the conventional liquid crystal display device, there is a problem in the moving image display characteristics due to the delay of the luminance change of the image based on the response speed of the liquid crystal, and there is a problem that the moving image quality is deteriorated due to moving image blur and afterimage feeling.

  Therefore, a method for improving the moving image display characteristics of a liquid crystal display device has been disclosed conventionally (see, for example, Patent Document 1). FIG. 5 is a block diagram showing an example of a correction circuit which is a main part of the liquid crystal display device described in Patent Document 1. In FIG. 5, input video data Sn is supplied to the frame memory 31 and accumulated for one frame, and then read out in synchronization with the current frame data to output video data Sn-1 delayed by one frame from the frame memory 31. Is done.

  The moving image correction processing data conversion unit 32 receives the video data Sn of the current frame and the video data Sn-1 delayed by one frame from the frame memory 31, and compares the video data of these two consecutive frames. By doing this, a change in signal level between corresponding pixels in the video data of the two frames before and after is detected, and a correction signal Sn ′ determined by the detected signal level and the change is generated.

  6 and 7 are diagrams schematically showing the relationship between the correction signal Sn 'generated by the correction circuit of FIG. 5 and the liquid crystal response. As shown in FIG. 6A, when the signal level of the video data Sn of the current frame changes to a value larger than the signal level of the video data Sn-1 of the previous frame in the same pixel, the change Overshoot correction signal Sn ′ is generated so as to emphasize (steepen) more and output as video data of the current frame.

  Accordingly, as shown in FIG. 6B, the liquid crystal response is obtained by adding an overshoot with the correction signal Sn ′ to the liquid crystal response (characteristic A) when the correction process is not applied, so that the response characteristic is B, As shown in C, the transition to the target luminance is improved in a shorter time.

  Similarly, as shown in FIG. 7A, when the signal level of the video data Sn of the current frame changes to a value smaller than the signal level of the video data Sn-1 of the previous frame in the same pixel. Then, an undershoot correction signal Sn ′ that emphasizes (steepens) the change is generated and output as video data of the current frame.

  Accordingly, as shown in FIG. 7B, the liquid crystal response is obtained by adding an undershoot with the correction signal Sn ′ to the liquid crystal response (characteristic A) when the correction process is not applied, so that the response characteristic is B, As shown in C, the transition to the target luminance is improved in a shorter time. In the emphasis processing of the response characteristic C shown in FIGS. 6B and 7B, the luminance change temporarily exceeding the target luminance is given, but the luminance integrated value in the change period is the luminance change of the ideal response. By determining the correction amount so as to be close, perceived motion blur is greatly improved.

JP 2002-82657 A

  By the way, there is a projection type liquid crystal display device as a method of a liquid crystal display device that enables high-definition display on a large screen. In a general three-plate projection type liquid crystal display device as a projection type liquid crystal display device, three liquid crystal display panels corresponding to three primary colors of light, R (red), G (green), and B (blue), are used. Each panel modulates the light of each primary color, optically color-combines them, and then projects an image on a screen with a projection lens.

  Thus, since the three-plate projection type liquid crystal display device uses three liquid crystal display panels corresponding to the three primary colors of RGB, there is essentially no case where the response characteristics of the three liquid crystal display panels are different. There is a problem that when a picture that is colored is displayed as a moving image, coloring occurs at the edge, and the display quality of the moving image is deteriorated.

  Here, the display characteristics of the liquid crystal display panel will be described with reference to FIGS. FIG. 8 is a schematic diagram showing the relationship between the thickness of the liquid crystal portion of the liquid crystal display panel and the response speed. As shown in the figure, the response speed of the liquid crystal display panel usually tends to increase as the thickness of the liquid crystal cell decreases. Therefore, in order to increase the response speed of the liquid crystal, it is effective to reduce the thickness of the liquid crystal cell, but the thickness of the liquid crystal cell of the liquid crystal display panel of the projection type liquid crystal display device is usually several μm. It is an order, and it is extremely difficult to form a uniform liquid crystal thickness within the display area.

  FIG. 9 is a contour diagram showing the in-plane thickness distribution in the liquid crystal display panel. In this way, when the in-plane liquid crystal cell thickness is uneven, A distribution of response characteristics occurs. In particular, since the above-described three-plate projection type liquid crystal display device uses three liquid crystal display panels corresponding to the three primary colors of RGB, if the distribution of the liquid crystal cell thickness differs between the color panels, The degree of difference between the colors of the response characteristics also results in in-plane distribution.

  FIG. 10 is a schematic diagram showing an example of applied voltage-output luminance (light intensity) characteristics of the liquid crystal display panel. In this example, it is assumed that black is displayed when the applied voltage of the liquid crystal is zero and “normally black” is displayed when white is displayed. As shown in FIG. 10, in the normally black display, under the condition that the applied voltage is constant, the applied voltage-output luminance characteristic depends on the thickness of the liquid crystal cell of the liquid crystal display panel. As the thickness of the liquid crystal cell increases, the output luminance, that is, the expression of the light modulation effect tends to increase for the same applied voltage.

  Since the three-plate projection type liquid crystal display device uses three liquid crystal display panels corresponding to the three primary colors of RGB, if the distribution of the liquid crystal cell thickness differs among the color panels, for example, the entire surface of an achromatic color (gray) When such an image is displayed, in-plane non-uniformity occurs in the output light quantity balance on the projection surface between the respective colors, and image quality deterioration due to color shading in a so-called still image occurs. In the three-plate projection type liquid crystal display device, a shading correction means for correcting the distribution difference of the in-plane output light of each color panel by signal processing on the video signal is usually applied to this color shading.

  Here, based on the applied voltage-output luminance characteristics shown in FIG. 10, the average liquid crystal cell in the portion where the liquid crystal cell thickness tends to be thicker in the in-plane position of the liquid crystal display panel. Since the light output tends to be excessive compared to the light output (output brightness) when displaying the achromatic color (gray) in the thick part, the corresponding liquid crystal cell thickness tends to be thicker at the pixel position. Correction processing is applied to the video signal in the direction of decreasing the applied voltage. That is, in a portion where the liquid crystal cell thickness tends to be thick, when the shading correction process is applied, the applied voltage is weakened.

  On the other hand, in the relationship between the liquid crystal cell thickness and the response speed described above, as shown in FIG. 8, when the thickness of the liquid crystal cell is thick, the response speed tends to be slow. The response speed of the liquid crystal has a property of changing depending on the applied voltage and the amount of difference between the applied voltage. As shown in FIG. 8, the liquid crystal cell whose response speed tends to be slower than that of other colors is thicker. Since the applied voltage is weakened by applying the shading correction process, the response speed is further slowed down. As a result, the coloring of the moving image edge due to the non-uniformity of the moving image response for each in-plane color tends to be emphasized.

  As described above, in a liquid crystal display device, particularly a three-plate projection type liquid crystal display device, when there is a difference in the distribution tendency of the liquid crystal cell thickness between the liquid crystal display panels of each primary color, the color of the response speed is partially There is a problem that an edge difference occurs, and edge coloring occurs in an in-plane distribution with respect to the movement of the achromatic image. In addition, when color shading correction processing is applied to a still image, coloring of the moving image edge tends to be further emphasized, and these problems are caused by applying the above-described video response correction processing by overdrive driving. Is also difficult to solve.

  The present invention has been made in view of the above points, and even when there is a difference in the distribution tendency of the liquid crystal layer thickness between the liquid crystal display panels of each primary color, there is no coloring of the moving image edge based on the moving image response characteristics. An object of the present invention is to provide a three-plate type liquid crystal display device capable of realizing excellent moving image display characteristics.

In order to achieve the above object, a first invention provides a drive circuit board in which a plurality of unit pixels including switching elements and display electrodes are arranged in a matrix, a translucent board in which a common electrode is formed, and a drive circuit board. Liquid crystal display panels each having a liquid crystal sandwiched between a liquid crystal display panel and a translucent substrate are provided corresponding to the three primary colors of light, and the primary color signals to be displayed on the respective primary color liquid crystal display panels A three-plate liquid crystal display device including a correction circuit that generates a correction signal that emphasizes a level change of the first color signal and supplies the correction signal as a drive signal to the liquid crystal display panel together with the primary color signal.
A memory circuit for storing and accumulating at least one frame of the primary color signal to be displayed in the correction circuit, and a primary color signal of the current frame input to the memory means by performing write control and read control of the primary color signal to the memory means A memory control unit that reads from the memory unit the primary color signal Sn-1 of the previous frame delayed by one frame period with respect to Sn, a subtracting unit that generates a difference signal between the primary color signals Sn and Sn-1 of the two frames before and after; For each of the m × n divided blocks obtained by dividing the display area of the liquid crystal display panel horizontally into m and vertically n, the liquid crystal response speed of the liquid crystal display panel corresponding to one pixel determined as a representative point is defined as a predetermined response speed. Correction data table in which all m × n representative values of coefficient data for moving image correction are stored in advance, and a plurality of representative points read from the correction data table Interpolation processing means for calculating correction data at each pixel coordinate surrounded by the plurality of representative points from the correction data by interpolation processing; multiplication means for multiplying the correction data calculated by the interpolation processing means and the difference signal; An addition means for generating a correction signal by adding the multiplication result of the multiplication means to the primary color signal Sn of the current frame is characterized.

  In the present invention, correction data at each pixel coordinate surrounded by a plurality of representative points is calculated by interpolation processing, multiplied by the difference signal, and the multiplication result is added to the primary color signal Sn of the current frame to generate a correction signal. Therefore, the correction signal can be generated not only according to the level change of the primary color signal to be displayed but also according to the two-dimensional coordinates of the display pixel.

In order to achieve the above object, the second invention provides a driving circuit board in which a plurality of unit pixels including switching elements and display electrodes are arranged in a matrix, a translucent board on which a common electrode is formed, and driving. Three liquid crystal display panels each having a liquid crystal sandwiched between a circuit board and a translucent substrate are provided corresponding to the three primary colors of light and should be displayed on each of the liquid crystal display panels of the respective primary colors. In a three-plate liquid crystal display device including a correction circuit that generates a correction signal that emphasizes a level change of a primary color signal and supplies the correction signal as a drive signal to the liquid crystal display panel together with the primary color signal.
A memory circuit for storing and accumulating at least one frame of the primary color signal to be displayed in the correction circuit, and a primary color signal of the current frame input to the memory means by performing write control and read control of the primary color signal to the memory means Memory control means for reading out the primary color signal Sn-1 of the previous frame delayed by 1 frame period from Sn from the memory means, and an m × n divided block obtained by dividing the display area of the liquid crystal display panel horizontally into m and vertically n For each of the above, a total of m × n moving image correction coefficient data representative values for setting the response speed of the liquid crystal display panel corresponding to one pixel determined as a representative point to a predetermined response speed are stored in advance. Correction at each pixel coordinate surrounded by the representative points from the correction data table and the correction data of the representative points read from the correction data table Interpolation processing means for calculating data by interpolation processing, and emphasis difference data for improving the response to each gradation level input of the primary color signal Sn of the current frame and the primary color signal Sn-1 of the previous frame are stored in advance. The reference table value is referenced based on the reference color table Sn, the current frame primary color signal Sn and the previous frame primary color signal Sn-1, and the gradation direction interpolation is performed based on a predetermined function. Gradation interpolation processing means for generating correction data, multiplication means for multiplying the difference correction data calculated by the gradation interpolation processing means and the correction data generated by the interpolation processing means, and the result of multiplication by the multiplication means for the current frame And adding means for generating a correction signal by adding to the primary color signal Sn.

  In the present invention, difference correction data obtained by performing interpolation in the gradation direction using the reference table and the gradation interpolation processing unit is generated, and the difference correction data is multiplied by the correction data generated by the interpolation processing unit. Since the multiplication result is added to the primary color signal Sn of the current frame to generate a correction signal, the response characteristic of the liquid crystal display panel is highly resistant to gradation dependence and nonlinearity based on the difference correction data. Video response correction with high accuracy is possible.

  According to the present invention, not only the level change of the primary color signal for displaying the correction signal but also the two-dimensional coordinates of the display pixel is generated. Even in the in-plane display pixels where there is a difference in the distribution tendency of the liquid crystal cell thickness, the moving image correction coefficient data representative value can be optimized, and this makes it possible to color moving image edges based on moving image response characteristics. It is possible to improve image quality degradation such as partial occurrence in the image.

  Further, according to the present invention, the difference correction data obtained by performing the interpolation in the gradation direction by the reference table and the gradation interpolation processing unit is generated, and the correction signal is generated based on the difference correction data. It is possible to correct the moving image response with high accuracy with respect to the gradation dependency and nonlinearity of the response characteristic of the display panel.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a main part of a liquid crystal display device according to a first embodiment of the present invention. As shown in the figure, the present embodiment includes a frame memory 11, a memory control unit 12, and a moving image correction processing data generation unit 13, and generates a correction signal Sn 'from the current frame signal Sn of the input video signal. To do. The correction signal Sn 'is input to a liquid crystal display panel (not shown). The liquid crystal display panel has the same configuration as the conventional one, and includes a drive circuit substrate in which a plurality of unit pixels including switching elements and display electrodes are regularly arranged in a two-dimensional matrix, a translucent substrate on which a common electrode is formed, The structure includes a liquid crystal sandwiched between the drive circuit board and the translucent board. Note that this embodiment is a three-plate liquid crystal display device, and the above-mentioned liquid crystal display panel is provided in total, one for each of the three primary colors of RGB, and the configuration of FIG. It is provided for each liquid crystal display panel (in FIG. 1, only the structure provided for one liquid crystal display panel is shown as a representative).

  The frame memory 11 is supplied with a video signal to be displayed (specifically, one of the primary color signals of R, G, and B, but hereinafter referred to as a video signal for convenience), and is controlled by the memory control unit 12. The input video signal is stored and accumulated frame by frame and read out with a delay of one frame period, thereby outputting the previous frame signal Sn-1 on the same time axis as the current frame signal Sn. The same pixel data of the current frame signal Sn and the previous frame signal Sn-1 from the frame memory 11 are supplied to the moving image correction processing data generation unit 13 at the same timing.

  The memory control unit 12 receives a horizontal synchronization signal H-Sync and a vertical synchronization signal V-Sync of a video signal to be displayed, and a clock CLK, generates a memory control signal, supplies it to the frame memory 11, and writes it. / Controls the readout operation and supplies control signals to an in-plane distribution correction coefficient table 16 and an interpolation processing unit 17 to be described later.

  The moving image correction processing data generation unit 13 includes a subtractor 14, a multiplier 15, an in-plane distribution correction coefficient table 16, an interpolation processing unit 17, and an adder 18. First, the moving image correction processing data generation unit 13 obtains a difference ΔS between the signal levels in each pixel of the current frame signal Sn and the previous frame signal Sn−1 by the subtractor 14.

  In the in-plane distribution correction coefficient table 16, as shown in FIG. 2, m × n moving image correction coefficients for m × n divided blocks obtained by horizontally dividing the display area of the liquid crystal display panel into m and vertically n. Data representative values D11, D21,..., Dmn are stored in advance. These dynamic image correction coefficient data representative values D11, D21,..., Dmn use the response speed of the liquid crystal display panel corresponding to one pixel determined as a representative point in each divided block as a predetermined response speed. This is a representative value for moving image correction coefficient data, and is measured in advance at the factory before product shipment and stored in the in-plane distribution correction coefficient table 16.

  The in-plane distribution correction coefficient table 16 is based on the read control signal supplied from the memory control unit 12 and is synchronized with the video signals Sn, Sn-1, and the moving picture correction coefficient data representative values D11, D21,. Read Dmn. According to the present embodiment, coefficient data Dij (where i = 1, 2,..., M, j = 1, 2,..., N) used for moving image response correction is stored in the correction target pixel. Different values can be used depending on the position.

  As shown in FIG. 3, the interpolation processing unit 17 represents representative point data D (i, j), D (i + 1, j), D (i, j + 1), D (i + 1, j + 1) around the correction target pixel. And a processing block for calculating a correction coefficient K (x, y) for each pixel by linear interpolation according to the distance from each representative point. Thus, according to the present embodiment, data for correcting the in-plane distribution of moving image characteristics is generated by interpolation processing from m × n moving image correction coefficient data representative values (the above representative point data). Therefore, it is not necessary to create a table of correction data for every pixel, and the memory capacity for the correction table can be saved.

  Returning to FIG. 1, the difference ΔS between the signal levels in each pixel of the current frame signal Sn and the previous frame signal Sn−1 calculated by the subtracter 14 and the in-plane distribution correction coefficient table 16 are read. The multiplier 15 multiplies the correction coefficient K (x, y) calculated by the linear interpolation by the interpolation processing unit 17 based on the moving image correction coefficient data representative value. Here, if the correction coefficient K (x, y) is set to “1” or more, the difference ΔS is output as a value ΔS ′ amplified by the multiplication processing in the multiplier 15.

  The adder 18 adds the difference signal ΔS ′ from the multiplier 15 that has amplified and emphasized the difference ΔS with respect to the previous frame signal Sn−1 to the current frame signal Sn to obtain a final correction signal Sn ′ to obtain a subsequent correction signal Sn ′. The drive signal is supplied to the liquid crystal display panel.

  As described above, according to the present embodiment, the processing coefficient for moving image characteristic correction caused by the liquid crystal response speed is not limited to the level change between the screens of the video signal to be displayed, but also the two-dimensional coordinates (x, y), since the liquid crystal cell thickness tendency of each color panel in the three-plate projection type liquid crystal display device varies, the representative value of coefficient data for moving image correction can be optimized. It is possible to improve image quality degradation such as coloring of moving image edges partially occurring in the plane.

  Next, a second embodiment of the present invention will be described. FIG. 4 shows a block diagram of the main part of the second embodiment of the liquid crystal display device according to the present invention. In the figure, the same components as those in FIG. The second embodiment takes into account not only the difference from the difference from the previous frame in the response characteristic of the liquid crystal display panel but also the nonlinear change depending on which level changes to which level, and the correction coefficient for the gradation change is set. The point realized by the reference table and the interpolation process is different from the first embodiment. Note that this embodiment is also a three-plate liquid crystal display device as in the first embodiment, and a total of three liquid crystal display panels are provided, one for each of the primary colors of RGB. The configuration of FIG. 4 is also provided for each liquid crystal display panel.

  The configuration and operation of the second embodiment will be described below. As shown in FIG. 4, the present embodiment includes a frame memory 11, a memory control unit 12, and a moving image correction processing data generation unit 20. The moving image correction processing data generation unit 20 includes an in-plane distribution correction coefficient table 16, an interpolation processing unit 17, a reference table 21, a gradation interpolation processing unit 22, a multiplier 23, and an adder 24.

  In the present embodiment, as in the first embodiment, the frame memory 11 controls the video signal data for one frame (specifically, among the R, G, B3 primary colors) under the control of the frame memory control unit 12. Is stored and accumulated, and is read out with a delay of one frame period, thereby outputting the previous frame signal Sn-1 on the same time axis as the current frame signal Sn. The same pixel data of the current frame signal Sn and the previous frame signal Sn-1 are supplied to the moving image correction processing data generation unit 20 at the same timing.

  The reference table 21 in the moving image correction processing data generation unit 20 defines and stores in advance the enhancement difference data for improving the response to each gradation level input of the current frame signal Sn and the previous frame signal Sn-1. is doing. At that time, if the enhancement difference data is defined for all the gradation level inputs for each of the current frame signal Sn and the previous frame signal Sn-1, a large table capacity is required. Emphasis difference data defining values for various gradation levels is stored in advance.

  The gradation interpolation processing unit 22 in the moving image correction processing data generation unit 20 refers to the value of the reference table 21 based on the input current frame signal Sn and previous frame signal Sn-1, and based on a predetermined function. Then, interpolation in the gradation direction is performed, and difference correction data ΔS ′ is output. In order to correct the moving picture response, it is a basic role of the gradation interpolation processing unit 22 to generate the difference correction data ΔS ′ for further emphasizing the change instead of the current frame signal Sn.

  Here, the actual processing of the previous frame signal Sn-1, which is a signal processing that takes into account the change from the level Ln-1 of the previous frame signal Sn-1 to the level Ln of the current frame signal Sn as the original information. If the relationship of the change from the level Ln-1 to the level Ln 'of the current frame signal Sn is defined for all combinations of levels (Ln-1, Ln), the level Ln- of the previous frame signal Sn-1 is defined. Based on the original information of 1 and the level Ln of the current frame signal Sn, it is necessary to define all combinations that generate Ln ′. In this case, assuming that the signals Sn-1 and Sn are 8-bit (256 gradations) video information, Sn ′ (Ln ′) used for correction is determined from 16-bit (= 8 bits + 8 bits) input information. A 16-bit input / 8-bit output conversion table is required as the conversion table.

On the other hand, in the gradation interpolation processing unit 22 in FIG. 4, the difference correction data ΔS ′ (or the correction signal Sn) to be output only for the combination of the representative values among the level combinations (Ln−1, Ln). ') Is defined as a reference table. Thus, for example, when the combination (Ln-1, Ln) of the actual levels of the signals Sn-1, Sn is (12, 40), for example, four representative values above and below surrounding this value as a range, for example (0, 32), (0, 48), (16, 32), and four converted data (table values) a, b, c, d for (16, 48) are used to determine the final correction value by calculation. Most simply, the centroid values of the four representative point data may be obtained by linear calculation, or a predetermined function for interpolation is defined in advance,
ΔS ′ = f (a, b, c, d, Sn−1, Sn)
Thus, the difference correction data ΔS ′ can be determined. The above f () is an approximation function based on the actual response characteristics of the display panel. In this way, the gradation interpolation processing unit 22 in FIG. 4 does not need to define correction data on a one-to-one basis for all combinations of gradation level changes, and has the effect of reducing the capacity of the data conversion table. can get.

  As in the first embodiment, the in-plane distribution correction coefficient table 16 in FIG. 4 includes m × n blocks for m × n divided blocks obtained by horizontally dividing the display area of the liquid crystal display panel into m and vertically n. , Dmn are stored in advance as moving image correction coefficient data representative values D11, D21,. A read control signal for the in-plane distribution correction coefficient table 16 is supplied from the memory control unit 12, and the moving picture correction coefficient data representative value D11 is read from the in-plane distribution correction coefficient table 16 in synchronization with the video signals Sn and Sn-1. , D21,..., Dmn are read out.

  Correction calculated by linear interpolation by the interpolation processing unit 17 based on the difference correction data ΔS ′ calculated by the gradation interpolation processing unit 22 and the moving image correction coefficient data representative value read from the in-plane distribution correction coefficient table 16 The coefficient K (x, y) is multiplied by the multiplier 23. The adder 24 adds the multiplication value of the difference correction data ΔS ′ from the multiplier 23 and the correction coefficient K (x, y) to the current frame signal Sn to obtain a final correction signal Sn ′ to obtain the subsequent liquid crystal. It is supplied as a drive signal to the display panel.

  As described above, in the liquid crystal display device according to the second embodiment of the present invention, the correction data generation is realized by the reference table 21 and the gradation interpolation processing unit 22, so that the response characteristics of the liquid crystal display panel can be improved. It is possible to correct a moving image response with high accuracy against gradation dependency and non-linearity. Further, similarly to the first embodiment, the correction coefficient for the gradation change can be set not only according to the level change of the video signal to be displayed but also according to the two-dimensional coordinates (x, y) of the display pixel. Even when the tendency of the liquid crystal layer thickness of each color panel in a three-plate projection type liquid crystal display device varies, image quality deterioration such as coloring of moving image edges is improved by optimizing the coefficient correction coefficient representative value. It is possible.

It is a block diagram of the principal part of 1st Embodiment of the liquid crystal display device of this invention. It is explanatory drawing of the coefficient data stored in the coefficient table for in-plane distribution correction | amendment in FIG. It is explanatory drawing of the correction data interpolation production | generation corresponding to the 1st Embodiment of this invention. It is a block diagram of the principal part of 2nd Embodiment of the liquid crystal display device of this invention. It is a block diagram of an example of the moving image correction processing circuit of the conventional liquid crystal display device. It is the signal waveform diagram for operation | movement description of the moving image correction process circuit of the conventional liquid crystal display device (the 1). It is the signal waveform diagram for operation | movement description of the moving image correction process circuit of the conventional liquid crystal display device (the 2). It is a figure which shows the characteristic of the liquid crystal cell thickness and response speed of the liquid crystal display panel of the conventional liquid crystal display device. It is a figure which shows the characteristic of the liquid crystal display panel of the conventional liquid crystal display device. It is a figure which shows the characteristic of the applied voltage and output luminance of the liquid crystal display panel of the conventional liquid crystal display device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Frame memory 12 Memory control part 13, 20 Movie correction process data generation part 14 Subtractor 15, 23 Multiplier 16 In-plane distribution correction coefficient table 17 Interpolation process part 18, 24 Adder 21 Reference table 22 Tone interpolation process part

Claims (2)

A drive circuit board in which a plurality of unit pixels including switching elements and display electrodes are arranged in a matrix, a translucent board on which a common electrode is formed, and the drive circuit board and the translucent board are sandwiched Three liquid crystal display panels each having a liquid crystal are provided corresponding to the three primary colors of light, and a correction signal is generated to emphasize the level change of the primary color signal to be displayed on each of the primary color liquid crystal display panels. In a three-plate type liquid crystal display device comprising a correction circuit that supplies the liquid crystal display panel as a drive signal together with the primary color signal,
The correction circuit;
Memory means for storing and storing at least one frame of the primary color signal to be displayed;
The primary color signal Sn-1 of the previous frame delayed by one frame period with respect to the primary color signal Sn of the current frame input to the memory means by performing write control and read control of the primary color signal to the memory means. Memory control means for reading from the memory means;
Subtracting means for generating a difference signal between the primary color signals Sn and Sn-1 of two frames before and after;
For each of the m × n divided blocks obtained by dividing the display area of the liquid crystal display panel into horizontal m and vertical n, the response speed of the liquid crystal of the liquid crystal display panel corresponding to one pixel determined as a representative point is set as a predetermined response. A correction data table in which mxn moving image correction coefficient data representative values for speed are stored in advance;
Interpolation processing means for calculating correction data at each pixel coordinate surrounded by the plurality of representative points from the correction data of the plurality of representative points read from the correction data table;
Multiplication means for multiplying the correction data calculated by the interpolation processing means and the difference signal;
A liquid crystal display device comprising: addition means for generating the correction signal by adding the multiplication result of the multiplication means to the primary color signal Sn of the current frame. A drive circuit board in which a plurality of unit pixels including switching elements and display electrodes are arranged in a matrix, a translucent board on which a common electrode is formed, and the drive circuit board and the translucent board are sandwiched Three liquid crystal display panels each having a liquid crystal are provided corresponding to the three primary colors of light, and a correction signal is generated to emphasize the level change of the primary color signal to be displayed on each of the primary color liquid crystal display panels. In a three-plate type liquid crystal display device comprising a correction circuit that supplies the liquid crystal display panel as a drive signal together with the primary color signal,
The correction circuit;
Memory means for storing and storing at least one frame of the primary color signal to be displayed;
The primary color signal Sn-1 of the previous frame delayed by one frame period with respect to the primary color signal Sn of the current frame input to the memory means by performing write control and read control of the primary color signal to the memory means. Memory control means for reading from the memory means;
For each of the m × n divided blocks obtained by dividing the display area of the liquid crystal display panel into horizontal m and vertical n, the response speed of the liquid crystal of the liquid crystal display panel corresponding to one pixel determined as a representative point is set as a predetermined response. A correction data table in which mxn moving image correction coefficient data representative values for speed are stored in advance;
Interpolation processing means for calculating correction data at each pixel coordinate surrounded by the plurality of representative points from the correction data of the plurality of representative points read from the correction data table;
A reference table in which enhancement difference data for improving response is stored in advance for each of the gradation level inputs of the primary color signal Sn of the current frame and the primary color signal Sn-1 of the previous frame;
Based on the primary color signal Sn of the current frame and the primary color signal Sn-1 of the previous frame, the value of the reference table is referred to, and interpolation in the gradation direction is performed based on a predetermined function to generate difference correction data Gradation interpolation processing means,
Multiplication means for multiplying the difference correction data calculated by the gradation interpolation processing means and the correction data generated by the interpolation processing means;
A liquid crystal display device comprising: addition means for generating the correction signal by adding the multiplication result of the multiplication means to the primary color signal Sn of the current frame.

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