JP4234178B2 - VIDEO DATA PROCESSING DEVICE, LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME, DISPLAY DEVICE DRIVE DEVICE, DISPLAY DEVICE DRIVE METHOD, PROGRAM THEREOF, AND RECORDING MEDIUM - Google Patents

Description

  The present invention is a video data processing apparatus that processes video data indicating the gradation of a pixel, and includes a video data processing apparatus capable of balancing reduction in circuit scale and improvement in display quality at a higher level. The present invention relates to a liquid crystal display device, a display device drive device, a display device drive method, a program thereof, and a recording medium.

  In addition to the features of space-saving and power-saving, liquid crystal display devices have recently been improved in performance such as viewing angle, contrast, color reproducibility, response speed and the like, and are now becoming image display devices that surpass CRTs. For this reason, the application of liquid crystal display devices to television and OA monitors (computer monitors) is expected to continue to expand.

  Normally, when a voltage is applied to the liquid crystal cell, the major axis direction (director) of the liquid crystal material (liquid crystal molecules) in the liquid crystal cell is changed by its dielectric anisotropy. Since the liquid crystal material has optical anisotropy, the polarization direction of the light transmitted through the liquid crystal cell changes when the direction is changed. The amount of light transmitted through the liquid crystal cell is controlled by an applied voltage (applied voltage) applied to the liquid crystal cell with the action of a polarizing plate or the like provided in the liquid crystal cell. As a result, the luminance of each pixel can be set to the gradation luminance to be displayed, and image display can be performed.

  However, a certain amount of time is required for the liquid crystal material to respond to changes in the applied voltage (the response speed of the liquid crystal material is slow). For example, in the case of TN (Twisted Nematic), IPS (In-Plane-Switching), VA (Vertically Aligned), or the like in a liquid crystal display mode (liquid crystal display mode) that is currently widely used, the response speed of the liquid crystal material is slow. It becomes 30 to 50 msec between gradations. Therefore, the response speed corresponding to 60 Hz (about 16.6 msec) of the NTSC (National Television System Committee) signal or 50 Hz (20.0 msec) of the PAL (Phase Alteration by Line) signal cannot be realized. Therefore, higher performance is required to meet the demand for further market expansion.

  In view of this, liquid crystal display devices have been developed in which liquid crystal materials and display driving methods have been devised to increase the response speed.

  For example, in Patent Document 1 (Japanese Patent Laid-Open No. 10-39837; publication date: February 13, 1998), a liquid crystal material is applied by applying a voltage larger than the voltage difference corresponding to the gradation change. A liquid crystal display device using “overshoot drive” that sharply moves the image to the target gradation is disclosed. In overshoot driving, an applied gradation value to be applied to a liquid crystal material in correspondence with a start gradation (current gradation) and a target gradation (desired gradation) (or an applied voltage value that realizes the applied gradation) A look-up table (LUT) that defines () is prepared in advance, and voltage application is performed based on this.

  Here, if an LUT storing values corresponding to applied voltage values corresponding to all gradation change patterns is prepared, there arises a problem that the capacity of the memory storing the LUT becomes extremely large.

  In order to solve this problem, in Patent Document 2 (Japanese Patent Laid-Open No. 2004-4629; date of publication: January 8, 2004), as shown in FIG. And the measurement data from the temperature sensor 108, and by performing an interpolation operation while referring to the plurality of LUTs stored in the LUT memory 112, the gradation data necessary for gradation display is set as the target gradation data. A liquid crystal display device including an applied gradation value acquisition unit 113 for calculation is disclosed. In this configuration, high-accuracy target gradation data (interpolation value) can be obtained by interpolation calculation using local coordinates while considering various additional conditions.

  However, in the configuration of Patent Document 2, the circuit scale is greatly reduced as compared with the configuration storing all patterns, while the display caused by the interpolation calculation is compared with the case where all patterns are stored. Some quality will occur. Therefore, it is required to further improve the display quality within a range that does not increase the circuit scale.

  An object of the present invention is to realize a display device that balances reduction in circuit scale and improvement in display quality at a higher level.

  In order to achieve the above object, a video data processing device according to the present invention stores video data indicating the gradation of a certain pixel that is repeatedly input until the next time, and the video data storage device Based on the previous video data and current video data read out from, corrected to enhance the gradation transition from the gray level indicated by the previous video data to the gray level indicated by the current video data Correction means capable of outputting video data, and the correction means corresponds to a predetermined combination among the combinations of values that can be taken by the previous and current video data, and corresponds to the combination. A parameter storage device storing parameters for determining corrected video data to be corrected, and a threshold value in which a difference between gradations indicated by both the input video data is determined in advance If the parameter corresponding to the input combination that is a combination of the values of both video data is not stored in the parameter storage device, a plurality of parameters are read from the parameter storage device, Interpolating means for calculating the parameter corresponding to the input combination and generating the corrected video data by interpolation based on the parameter, and outputting the current video data without correction when the threshold is not exceeded, The parameter storage device is determined by the parameter as a parameter corresponding to a specific combination in which the gradations indicated by the values constituting the combination are the same among the predetermined partial combinations. The gradation indicated by the corrected video data is the specific combination If the difference between the gradations indicated by the values constituting the input combination exceeds the threshold value, the parameter corresponding to the input combination is calculated by the interpolation calculation. The parameter for storing is memorize | stored.

  In the above configuration, when the difference between gradations indicated by the input video data exceeds a predetermined threshold, the video data processing apparatus can output corrected video data in which gradation transition is emphasized. Therefore, the response speed of the pixels of the display device that displays the video data can be improved.

  In addition, the interpolation means does not perform gradation transition enhancement when the amount of gradation transition does not exceed the threshold value. Therefore, for example, in the case of displaying a still image, for example, noise is displayed. It is possible to emphasize the gradation transition that occurs slightly due to the influence of the above, and to prevent the occurrence of the problem that the unwanted gradation transition is visually recognized by the user.

  Furthermore, the parameter storage device stores only the parameters corresponding to a part of the combinations of values that can be taken by the current and previous video data, and the parameters corresponding to the remaining combinations are calculated by interpolation. Therefore, the circuit scale can be greatly reduced as compared with storing parameters corresponding to all combinations in the parameter storage device.

  Further, in the parameter storage device, corresponding to the specific combination, the following parameters, that is, the gradations indicated by the corrected video data determined by the parameters are the levels indicated by the values constituting the specific combination. Stores a parameter for calculating a parameter corresponding to the input combination by the interpolation calculation when the difference between the gradations indicated by the values constituting the input combination exceeds the threshold value. Has been. Therefore, in response to a specific combination in which no gradation transition occurs, an error caused by approximation using interpolation calculation is compared with a configuration in which any of the gradations indicated by the values constituting the specific combination is stored. The display quality when displayed on the display device can be improved.

  As a result, it is possible to realize a display device that balances reduction in circuit scale and improvement in display quality at a higher level.

  In addition, when the parameters as described above are stored corresponding to the specific combination, if an interpolation calculation is used when the amount of gradation transition is equal to or less than the threshold, an error caused by approximation using the interpolation calculation May become large. However, the interpolation means does not perform gradation transition enhancement when the amount of gradation transition does not exceed the threshold value. Therefore, when the amount of gradation transition is equal to or less than the threshold value, the error does not occur, and display quality deterioration due to the error can be prevented.

  In order to achieve the above object, the display device driving device according to the present invention includes a correction unit that corrects and outputs video data indicating the gradation of a certain pixel that is repeatedly input, and a corrected video image. A display device driving device including output means for outputting a signal corresponding to data to a data signal line connected to the pixel, wherein the uncorrected video data inputted repeatedly is D (n−1). ), D (n), and the corrected video data corresponding thereto are D2 (n−1) and D2 (n), the correction means has the gradation transition amount of the video data before correction in advance. When larger than the predetermined threshold L, D2 (n) = α + k · [(D (n−1) −D (n)]) is output as the corrected video data D2 (n), and the correcting means Indicates that the gradation transition amount of the video data before correction satisfies the threshold value L. In this case, D2 (n) = D (n) is output as the corrected video data D2 (n), and α is set to a value different from D (n). .

  In this configuration, when the gradation transition amount of the video data before correction is larger than a predetermined threshold L, the corrected video data D2 (n) is D2 (n) = α + k · [(D (n -1) -D (n)] is output, and when the gradation transition amount of the video data before correction is less than the threshold value L, D2 (n) = D as the video data D2 (n) after correction. (N) is output, and α is set to a value different from D (n).

  Therefore, in the same manner as the video data processing apparatus, the following configuration, that is, the configuration storing one of the gradations indicated by the values constituting the specific combination corresponding to the specific combination where the gradation transition does not occur is compared. Thus, errors due to approximation using interpolation calculation can be reduced, and display quality when displayed on a display device can be improved. As a result, it is possible to realize a display device that balances reduction in circuit scale and improvement in display quality at a higher level.

  Other objects, features, and advantages of the present invention will be fully understood from the following description. The advantages of the present invention will become apparent from the following description with reference to the accompanying drawings.

1, showing an embodiment of the present invention, is a block diagram illustrating a main configuration of a modulation drive processing unit. FIG. It is a block diagram which shows the principal part structure of an image display apparatus provided with the said modulation | alteration drive process part. It is a circuit diagram which shows the structural example of the pixel of the said image display apparatus. 4 is a diagram illustrating output video data stored in a lookup table of the modulation drive processing unit. 6 is a diagram illustrating a combination of previous and current frame video data in which corresponding output video data is stored in the lookup table. It is a graph which shows the relationship between the ideal characteristic of the said output video data, and the output video data produced | generated by the interpolation calculation. 9 is a view showing another embodiment of the present invention and showing output video data stored in a lookup table of the modulation drive processing unit. FIG. 32 is a block diagram illustrating a main configuration of a modulation drive processing unit according to still another embodiment of the present invention. It is a block diagram which shows a prior art and shows the structure of a liquid crystal display device.

Explanation of symbols

1. 1a to 1b Image display device (liquid crystal display device)
21 · 21a to 21b Modulation drive processing unit (video data processing device)
31 frame memory (video data storage device)
35 / 35a Look-up table (parameter storage device)
34 / 34a to 34b Modulation processing unit (interpolation means)
V Video data value (parameter)
V1 ・ V2 Video data value (first and second parameters)
V1 · V2a Difference value of video data values (first and second parameters)

[First Embodiment]
An embodiment of the present invention will be described below with reference to FIGS. That is, the image display device according to the present embodiment interpolates the values stored in the lookup table (LUT) when the amount of gradation transition from the previous time to the current time is larger than a predetermined threshold value. When the tone transition is emphasized and is equal to or less than a predetermined threshold, the image display device emphasizes the tone transition, and can perform more appropriate interpolation without increasing the circuit scale of the lookup table.

  As shown in FIG. 2, the panel 11 of the image display device 1 includes a pixel array 2 having pixels PIX (1,1) to PIX (n, m) arranged in a matrix, and data signals of the pixel array 2. A data signal line driving circuit 3 for driving the lines SL1 to SLn and a scanning signal line driving circuit 4 for driving the scanning signal lines GL1 to GLm of the pixel array 2 are provided. In addition, the image display device 1 includes a control circuit 12 that supplies control signals to both the drive circuits 3 and 4, and the control circuit 12 that emphasizes the gradation transition based on the input video signal. A modulation drive processing unit (video data processing device) 21 for modulating a video signal to be applied is provided. These circuits are operated by power supply from the power supply circuit 13.

  Below, before explaining the detailed configuration of the modulation drive processing unit 21 as a drive device of the display device, the overall configuration and operation of the entire image display device (liquid crystal display device) 1 will be described. For convenience of description, for example, only when the position needs to be specified as in the i-th data signal line SLi, it is not necessary to specify the position by referring to the position with a numeral or alphabetic character. When referring to the case or generically, the characters indicating the position are omitted for reference.

  The pixel array 2 includes a plurality (in this case, n) of data signal lines SL1 to SLn and a plurality (in this case, m) of scanning signal lines GL1 that intersect the data signal lines SL1 to SLn, respectively. GLm, and an arbitrary integer from 1 to n and an arbitrary integer from 1 to m are j, a pixel PIX (i, j for each combination of the data signal line SLi and the scanning signal line GLj. ) Is provided. In the present embodiment, each pixel PIX (i, j) includes two adjacent data signal lines SL (i−1) and SLi and two adjacent scanning signal lines GL (j−1). -It is arranged in the part surrounded by GLj.

  The image display device 1 according to the present embodiment is a liquid crystal display device, and the pixel PIX (i, j) has a gate as a switching element, for example, as shown in FIG. 3, and a drain to a scanning signal line GLj. Is connected to the data signal line SLi, and a pixel capacitor Cp (i, j) having one electrode connected to the source of the field effect transistor SW (i, j). I have. The other end of the pixel capacitor Cp (i, j) is connected to a common electrode line common to all the pixels PIX. The pixel capacitor Cp (i, j) includes a liquid crystal capacitor CL (i, j) and an auxiliary capacitor Cs (i, j) that is added as necessary.

  When the scanning signal line GLj is selected in the pixel PIX (i, j), the field effect transistor SW (i, j) is turned on, and the voltage applied to the data signal line SLi is changed to the pixel capacitance Cp (i, j). ). On the other hand, while the selection period of the scanning signal line GLj ends and the field effect transistor SW (i, j) is cut off, the pixel capacitor Cp (i, j) continues to hold the voltage at the cut-off. Here, the transmittance or reflectance of the liquid crystal varies depending on the voltage applied to the liquid crystal capacitance CL (i, j). Therefore, if the scanning signal line GLj is selected and a voltage corresponding to the video data D to the pixel PIX (i, j) is applied to the data signal line SLi, the display state of the pixel PIX (i, j) is It can be changed in accordance with the video data D.

  In the image display device 1 according to the present embodiment, as a liquid crystal cell used for the pixel array 2, a liquid crystal cell in a vertical alignment mode, that is, when no voltage is applied, liquid crystal molecules are aligned substantially perpendicular to the substrate, and the pixel PIX ( The liquid crystal cell in which the liquid crystal molecules are inclined from the vertical alignment state in accordance with the voltage applied to the liquid crystal capacitance CL (i, j) of i, x) is employed, and the liquid crystal cell is normally black mode (no voltage applied). Sometimes used in black display mode).

  In the above configuration, the scanning signal line drive circuit 4 shown in FIG. 2 outputs a signal indicating whether or not the selected period, such as a voltage signal, to each of the scanning signal lines GL1 to GLm. Further, the scanning signal line drive circuit 4 changes the scanning signal line GLj that outputs a signal indicating the selection period based on a timing signal such as a clock signal GCK or a start pulse signal GSP given from the control circuit 12, for example. Yes. Thus, the scanning signal lines GL1 to GLm are sequentially selected at a predetermined timing.

  Further, the data signal line driving circuit 3 extracts the video data D... To the respective pixels PIX... Input in a time division manner as the video signal DAT by sampling at a predetermined timing. Further, the data signal line driving circuit 3 supplies the data signal lines SL1 to SLIX to the pixels PIX (1, j) to PIX (n, j) corresponding to the scanning signal line GLj selected by the scanning signal line driving circuit 4. An output signal corresponding to each video data D ... is output via SLn.

  The data signal line driving circuit 3 determines the sampling timing and the output timing of the output signal based on timing signals such as the clock signal SCK and the start pulse signal SSP input from the control circuit 12.

  On the other hand, each of the pixels PIX (1, j) to PIX (n, j) outputs to the data signal lines SL1 to SLn corresponding to the pixels PIX (1, j) to PIX (n, j) while the scanning signal line GLj corresponding to the pixels PIX (1, j) to PIX (n, j) is selected. Depending on the signal, the brightness is adjusted by adjusting the transmittance and the like.

  Here, the scanning signal line driving circuit 4 sequentially selects the scanning signal lines GL1 to GLm. Therefore, all the pixels PIX (1, 1) to PIX (n, m) of the pixel array 2 can be set to the brightness (gradation) indicated by the video data D to each, and the image displayed on the pixel array 2 can be displayed. Can be updated.

  The video data D may be the gradation level itself or a parameter for calculating the gradation level as long as the gradation level of the pixel PIX (i, j) can be specified. As an example, the case where the video data is the gradation level of the pixel PIX (i, j) will be described.

  In the image display device 1, the video signal DAT supplied from the video signal source VS0 to the modulation drive processing unit 21 may be transmitted in units of frames (units of the entire screen), and one frame is divided into a plurality of fields. Although the data may be divided and transmitted in the field unit, the case where the data is transmitted in the field unit will be described below as an example.

  That is, in this embodiment, the video signal DAT supplied from the video signal source VS0 to the modulation drive processing unit 21 is divided into a plurality of fields (for example, two fields) and transmitted in units of the field. .

  More specifically, when the video signal source VS0 transmits all the video data for a certain field when transmitting the video signal DAT to the modulation drive processing unit 21 of the image display device 1 via the video signal line VL, The video data for each field is transmitted in a time-sharing manner, for example, by transmitting video data for the next field.

  The field is composed of a plurality of horizontal lines. For example, in the video signal line VL, after all video data for a certain horizontal line is transmitted in a certain field, the horizontal line is transmitted next. For example, the video data for each horizontal line is transmitted in a time division manner.

  In this embodiment, one frame is composed of two fields, and in the even field, the video data of the horizontal line of the even-numbered row among the horizontal lines constituting one frame is transmitted. In the odd field, the video data of the horizontal line of the odd row is transmitted. Further, the video signal source VS0 drives the video signal line VL in a time-sharing manner when transmitting video data for one horizontal line, and the video data is sequentially transmitted in a predetermined order.

  Here, as shown in FIG. 1, the modulation drive processing unit 21 according to the present embodiment basically includes a frame memory (video data storage device) 31 that stores video data for one frame up to the next frame, and basically. The video data D (i, j, k) of the current frame FR (k) input to the input terminal T1 is written into the frame memory 31, and the video data D0 (from the frame memory 31 of the previous frame FR (k−1)). Based on the memory control circuit 32 that reads out and outputs i, j, k-1) and both the video data D (i, j, k) and D0 (i, j, k-1), the both video data. Based on D (i, j, k) · D0 (i, j, k−1), the determination processing unit 33 for determining whether or not gradation transition enhancement is necessary, and when gradation transition enhancement is necessary, Both video data D (i, j, k) .D0 (i, j, k-1) Based on the video data D (i) of the current frame FR (k) so as to emphasize the gradation transition from the current frame FR (k) to the previous frame FR (k−1) in the pixel PIX (i, j). , J, k) are corrected and output, and if unnecessary, the modulation processing unit (interpolation means) 34 for outputting the video data D (i, j, k) itself and the modulation processing unit 34 correct it. And a look-up table (LUT; parameter storage device) 35 referred to at the time.

  Hereinafter, the signal output from the modulation processing unit 34 is referred to as an output video signal DAT2 regardless of whether or not correction is performed, and among the output video data D2 constituting the output video signal DAT2, the video data D (i, j, k) and data corresponding to D0 (i, j, k-1) are referred to as output video data D2 (i, j, k). Further, in each part of the image display device 1, a pixel based on the output video data D <b> 2 (i, j, k) regardless of whether the signal, data, voltage, or luminance exists at the same time. The voltage applied to PIX (i, j) is the voltage of the current frame FR (k), the frame to which the voltage is applied is the current frame FR (k), and the pixel PIX (i, j) is represented by the voltage. The luminance that reaches the end point of the frame FR (k) is referred to as the luminance of the current frame FR (k).

  The LUT 35 basically includes values (gradations) that the video data D (i, j, k-1) of the previous frame FR (k-1) can take and video data of the current frame FR (k). Out of combinations with possible values (gradations) of D (i, j, k), for each of the predetermined combinations, output video data D2 after correction to be output when the combination is input ( i, j, k) are stored. Here, the value stored in the LUT 35 is determined by the characteristics of the pixel array 2. In the present embodiment, when a voltage corresponding to the second gradation is applied to the pixel PIX (i, j) in a state where the luminance of the pixel PIX (i, j) is the luminance indicated by the first gradation, When the pixel PIX (i, j) reaches the luminance indicated by the third gradation at the end of the frame in which the voltage is applied, the LUT 35 basically includes the first gradation, the third gradation, Corresponding to these combinations, data indicating the second gradation is stored.

  As an example, in the present embodiment, the values that can be taken by the video data D0 and the video data D of the previous frame are 0 to 255, respectively, and the LUT 35 is specified by a combination of both as shown in FIG. When the area is divided into 8 × 8 small areas, video data D2 corresponding to the four corner points of each small area is stored as shown in FIG. In this example, the area is a two-dimensional space from (0, 0) to (255, 255). Therefore, when divided into 8 × 8 small areas, each small area has 32 gradations × It becomes a region of 32 gradations. Therefore, in this case, the LUT 35 stores 9 × 9 points formed by combinations of gradations every 32 gradations.

  When the correction is instructed from the determination processing unit 33, the modulation processing unit 34 linearly interpolates between the video data D2 corresponding to each combination stored in the LUT 35 before being actually input. The video data D2 corresponding to the combination of the frame representative value D0 (i, j, k-1) and the video data D (i, j, k) can be calculated and output.

More specifically, the modulation processing unit 34 according to the present embodiment receives the combination (S, E) of both the video data D0 (i, j, k-1) and D (i, j, k). At this time, it is specified to which of the small areas as the calculation area the combination belongs. Further, the modulation processing unit 34 sets the arrival gradations at the four corners of the calculation area as A, B, C, and D in the order of the upper left corner, the upper right corner, the lower right corner, and the lower left corner, respectively. The value obtained by normalizing the difference between the combination of the upper left corner (S0, E0) and the above combination (S, E) to (1, 1) is (Δy, Δx) = ((S−S0 ) / Y, (E−E0) / X), when Δx> = Δy, the arithmetic circuit 72 reads out each of the reached gradations A, B, and C from the LUT 35, and the following equation (1) As shown in
D2 (i, j, k) = A + Δx · (BA) + Δy · (CB) (1)
To calculate D2 (i, j, k).

On the other hand, in the case of Δx <Δy, the modulation processing unit 34 reads each of the reached gradations A, C, and D from the LUT 35 and, as shown in the following formula (2),
D2 (i, j, k) = C + Δx · (C−D) + (1−Δy) · (D−A) (2)
To calculate D2 (i, j, k).

  For example, in the example of FIGS. 4 and 5, when (S, E) is (144, 48), it is surrounded by (128, 32), (128, 64), (160, 64) and (160, 32). The calculated calculation area is specified, and the corrected video data D2 (i, j, k) becomes 60.

  Incidentally, as described above, the LUT 35 according to the present embodiment basically stores data indicating the second gradation corresponding to the combination of the first gradation and the third gradation. However, as an exception, for a combination of gradations where gradation transition does not occur (a combination in which the values of both video data D (i, j, k) · D0 (i, j, k−1) are equal to each other). Thus, the LUT 35 calculates the video data D2 (i, j, k) in the correction range by interpolation calculation instead of the second gradation value (D (i, j, k) value itself). A value V larger than the value of the second gradation is stored as a value set so that the error in minimizing is minimized. Furthermore, in the present embodiment, as a more preferable setting, the error is set to be the smallest in a range where there is no region in which correction is too strong in the correction range. In FIG. 6, for example, the value when the gradation indicated by the video data D (i, j, k) of the current frame FR (k) is 32 gradations is indicated after V as V (32). A value indicating the value of the video data D (i, j, k) of the current frame FR (k) is attached.

  Furthermore, the modulation processing unit 34 according to the present embodiment corresponds to a combination (D0 = D combination) in which gradation transition does not occur in the value to be read from the LUT 35 in the case of decay gradation transition. If a value is included, instead of reading the value corresponding to the combination from the LUT 35, the video data D0 of the previous frame FR (k-1) itself or the video data D of the current frame FR (k) Can be used for interpolation calculation. The case where the gradation transition is decay is a case where the luminance decreases due to the gradation transition, and the video data D of the current frame FR (k) is more than the video data D0 of the previous frame FR (k−1). Is smaller.

  In the following, referring to FIG. 6, the coordinates (0, 32), (0, 64), (32) of (S, E) are assumed to be small areas having a point where gradation transition does not occur at one of the four corners. , 64) and (32, 32) as an example, the value stored in the LUT 35 will be described by taking the small area A1 as an example.

  Here, how only the video data D2 of the current frame FR (k) is changed from the coordinates (32, 32) to (32, 64), how the optimal video data D2 changes. When S-E is plotted on the horizontal axis and the optimum value of the video data D2 is plotted on the vertical axis, the characteristic C1 shown by a two-dot chain curve in FIG. 6 is obtained. Note that the optimal value of the video data D2 can be determined in the same manner as the other values of the LUT 35 described above (values when no gradation transition occurs).

  On the other hand, as a first comparative example, the LUT 35 stores the video data D itself of the current frame FR (k) corresponding to the combination of gradations where gradation transition does not occur, and the modulation processing unit is always linear. In the configuration for interpolation, the characteristic of the video data D2 is a characteristic C2 indicated by a broken line in FIG.

  Further, as a second comparative example, similar to the modulation processing unit 34 according to the present embodiment, when the gradation transition amount (ES) is less than the predetermined threshold L, the gradation transition is not emphasized. In the configuration, the characteristic of the video data D2 output from the modulation processing unit is a characteristic C3 indicated by a solid broken line in FIG.

  However, in the configuration of the second comparative example, since the video data D itself of the current frame FR (k) is stored corresponding to the combination of gradations in which no gradation transition occurs, SE is a threshold value. At a location larger than L, the output video data D2 has a value significantly lower than the ideal characteristic C1 described above.

  On the other hand, the LUT 35 according to the present embodiment stores a value larger than the video data D of the current frame FR (k) corresponding to the combination of gradations in which no gradation transition occurs. Therefore, the modulation processing unit 34 can output the video data D2 having the characteristic C4 shown by the solid broken line in FIG.

  More specifically, when the video data before correction is D (n−1) and D (n) and the corresponding video data after correction is D2 (n−1) and D2 (n), The broken line characteristic C4 indicates that when the gradation transition amount of the uncorrected video data before correction is less than the threshold value L, D2 (n) = D (n), and the gradation transition amount is greater than the threshold value L. Is also large, D2 (n) = α + k · [(D (n) −D (n−1)]) Note that in the example of FIG, D2 (n) = D2, D (n) = D, Since D (n−1) = 32, when the gradation transition amount is larger than the threshold value L, D2 = α + k · (D−32). When the gradation transition amount is less than the threshold value L, D2 = D.

  Here, in the present embodiment, since a value larger than the video data D of the current frame FR (k) is stored corresponding to a combination of gradations in which no gradation transition occurs, the second comparative example described above. The video data D2 after linear interpolation has a larger value than the configuration of. Therefore, the modulation processing unit 34 can output video data D2 that is closer to the ideal characteristic C1.

  In FIG. 6, as an example, the video data D0 of the previous frame FR (k−1) is fixed to a constant value (32 gradations in FIG. 6), and only the video data D of the current frame FR (k). Has been described with respect to the characteristics of the corrected video data D2 when increased from the same value as the video data D0. As shown below, “in the case of rise gradation transition, the configuration of the second comparative example It is generally true that the modulation processing unit 34 according to the present embodiment can output video data D2 that is closer to the ideal characteristic C1 than "." Note that the case where the gradation transition is rise is a case where the luminance increases due to the gradation transition, and the video data D of the current frame FR (k) is higher than the video data D0 of the previous frame FR (k−1). Is larger (more precisely, the luminance indicated by the video data D is higher than the luminance indicated by the video data D0).

  That is, although the pixel array 2 according to the present embodiment is a liquid crystal display panel, generally, the larger the gradation difference, the torque that needs to be applied to the liquid crystal molecules for response or the torque that is applied to the liquid crystal molecules at the time of response. Becomes larger. Therefore, as the moving distance increases, the observed response time becomes shorter. As a result, when the modulation processing unit 34 is configured to generate the video data D2 by linear interpolation, the correction becomes insufficient as the gradation difference becomes smaller, and the video data D2 generated by interpolation with respect to the gradation transition amount; The ratio of the difference from the ideal value of the video data D2 tends to increase.

  In other words, when the gradation transition is Rise, the combination of the video data D0 of the previous frame FR (k−1) and the video data D of the current frame FR (k) is changed as shown in FIG. Similarly to the above, even when the characteristic C1 of the ideal video data D2 with respect to the gradation transition amount (ES) is drawn, the characteristic C1 is convex upward in a range where gradation transition enhancement is required. It becomes a curve.

  As a result, as described above in the second comparative example, when the gradation transition does not occur, if the linear interpolation is performed so that the video data D itself of the current frame FR (k) can be output, the gradation transition enhancement is required. In this case, only the video data D2 smaller than the ideal value can always be output.

  On the other hand, if the modulation processing unit 34 according to the present embodiment outputs a linearly interpolated value even when gradation transition does not occur as described above, the video data D of the current frame FR (k). Linear interpolation is performed so that a larger value can be output. Therefore, the identification of the video data D2 output from the modulation processing unit 34 is as indicated by C4 in the figure, and the modulation processing unit 34 can output the video data D2 closer to the ideal characteristic C1. it can.

  Here, the value V referred to when outputting the C4 is calculated as follows, for example. Specifically, when the point when the gradation transition amount is maximum is P1, and the point when the gradation transition amount is L is P2, P1 and P2 are connected by a straight line, and the straight line is S The video data D2 at the point P3 that intersects the straight line of = 32 (the straight line where the video data D is the minimum value) is V. More preferably, when selecting P2, it is desirable to select P2 within a range in which the correction amount in the correction section does not exceed the ideal value (that is, there is no overcorrection).

  Since the linear interpolation by the modulation processing unit 34 is set as described above, if a value obtained by linear interpolation is output even when no gradation transition occurs, it is larger than the video data D. The value is output. In this case, the luminance of the pixel PIX is controlled to the correct luminance (the luminance indicated by the video data D of the current frame FR (k)) when there is no gradation transition as in the case of displaying a still image. The display quality of the image display device 1 is degraded.

  However, when the gradation transition amount (SE) is smaller than the predetermined threshold L, the modulation processing unit 34 according to the present embodiment does not perform gradation transition enhancement, and the video of the current frame FR (k). Data D itself is output. Therefore, even if the linear interpolation by the modulation processing unit 34 is set as described above, the image display device 1 can control the luminance of the pixel PIX to the correct luminance without any trouble even when displaying a still image. Display quality can be prevented from deteriorating.

  In the above description, the case of rise gradation transition has been described as an example. However, even in the case of decay gradation transition, although the principle is different, it can be considered substantially the same. That is, in the case of decay, the response is based on the relaxation of the elastic body, but the greater the tone difference, the greater the torque that must be applied to the liquid crystal molecules for response, or the torque that is applied to the liquid crystal molecules during response. . Therefore, as the moving distance increases, the response speed of the liquid crystal molecules itself increases, and the response time can be further shortened when the correction amount is the same.

  Similarly, the greater the gradation difference, the greater the torque that must be applied to the liquid crystal molecules for response, or the torque that is applied to the liquid crystal molecules at the time of response. Becomes shorter.

  As a result, when the modulation processing unit 34 is configured to generate the video data D2 by linear interpolation, the correction becomes insufficient as the gradation difference becomes smaller, and the video data D2 generated by interpolation with respect to the gradation transition amount; The ratio of the difference from the ideal value of the video data D2 tends to increase.

  Therefore, when the gradation transition is decaying, the combination of the video data D0 of the previous frame FR (k-1) and the video data D of the current frame FR (k) is changed as shown in FIG. Similarly, even when the characteristic C1 of the ideal video data D2 with respect to the gradation transition amount (ES) is drawn, the characteristic C1 has a downwardly convex curve in a range where gradation transition enhancement is required. become.

  As a result, as described above in the second comparative example, when the gradation transition does not occur, if the linear interpolation is performed so that the video data D itself of the current frame FR (k) can be output, the gradation transition enhancement is required. In this case, only the video data D2 larger than the ideal value can always be output.

  However, when the vertical alignment mode liquid crystal cell is used in the normally black mode as in this embodiment, the response characteristic to the gradation transition in the decay direction is compared with the response characteristic to the gradation transition in the rise direction. Therefore, it is difficult to be influenced by the level of the gradation transition amount, and the above-described correction insufficiency does not occur much.

  In addition, when a vertical alignment mode liquid crystal cell is used in a normally black mode, the response characteristic in the rise direction is particularly susceptible to the amount of gradation transition. Further, particularly at the time of gradation transition starting from 0 gradation, since the response is very slow, a large amount of correction is necessary (the difference between the uncorrected video data D and the corrected video data D2 is large). ).

  Therefore, the following configuration, that is, not only storing values for correcting the video data D at the time of transition in the rise direction with high precision, but also storing the video data D at the time of transition in gray scale in the decay direction with high precision. Compared with the configuration stored in the LUT 35, the circuit scale can be reduced without reducing the display quality.

[Second Embodiment]
In the present embodiment, a configuration for suppressing the above-described correction insufficiency will be described with reference to FIG. 7 not only in the gradation transition in the rise direction but also in the gradation transition in the decay direction.

  That is, as shown in FIG. 1, the modulation drive processing unit 21 a according to the present embodiment has substantially the same configuration as the modulation drive processing unit 21 according to the first embodiment, but is replaced with the modulation processing unit 34 and the LUT 35. Thus, a modulation processing unit 34a and an LUT 35a are provided.

  The LUT 35a is substantially the same as the LUT 35 shown in FIG. 5. However, as shown in FIG. 7, only the value V1 for emphasizing the gradation transition in the rise direction corresponds to the combination where the gradation transition does not occur. In addition, a value V2 for emphasizing gradation transition in the decay direction is also stored. These values V1 and V2 correspond to the first and second parameters described in the claims.

  Here, the decay direction value V2 is smaller than the video data D2 = D0 = D. The value V2 is substantially the same as in the first embodiment. For example, when the point when the gradation transition amount is maximum is P1, and the point when the gradation transition amount is L is P2, P1 And P2 are connected by a straight line, and the video data D2 at the point P3 when the current video data D is minimized is V. As in the rise method, when selecting P2, the error from the ideal value is minimized within a range in which the correction amount in the correction section does not exceed the ideal value (because it is a decay, it does not fall below the correction value). It is preferable to make such a selection.

  The modulation processing unit 34a is substantially the same as the modulation processing unit 34. However, when a value corresponding to a combination in which gradation transition does not occur is read from the LUT 35a, the modulation processing unit 34a and the video data D of the current frame FR (k) Based on the video data D0 of the previous frame FR (k−1), it is determined whether the gradation transition is the rise direction or the decay direction. If the transition is in the decay direction, 2 stored in the LUT 35a corresponding to the combination. Of the two values V1 and V2, the value V2 for the decay direction can be read out. On the other hand, in the rise direction, the value V1 for the rise direction can be read out of the two values V1 and V2.

  Here, the values V1 and V2 may be stored as they are, but in the present embodiment, the values V1 and V2 are used as the video data D (of the current frame FR (k) in order to reduce the storage capacity. Alternatively, it is stored in the form of a difference value with respect to the video data D0) of the previous frame FR (k−1), and the value V1a or V2a read from the LUT 35 is added to or subtracted from the video data D (or D0). Thus, the values V1 and V2 before the difference can be restored.

  In the above configuration, as in the first embodiment, not only the insufficient correction at the time of transition in the rise direction can be suppressed, but also the above-described correction in the gradation direction of the decay direction can be suppressed. Compared to the configuration of the comparative example, it is possible to output larger video data D2 that is closer to the ideal characteristic C1.

  In the present embodiment, as in the first embodiment, when the gradation transition amount falls below the threshold value L, the modulation processing unit 34a does not emphasize the gradation transition, so that the display quality at the time of still image display is improved. Decline can be prevented.

[Third Embodiment]
In the present embodiment, a configuration capable of switching between the LUT 35 of the first embodiment and the LUT 35a of the second embodiment according to the situation will be described with reference to FIG. As triggers for changing the value to be stored in the LUT (the degree of gradation transition emphasis), there are various triggers including, for example, temperature and the type of image to be displayed (whether the image has a lot of motion, etc.) Although a trigger is conceivable, in the following, a case will be described in which the LUT is switched using temperature as a trigger.

  More specifically, when the rise direction value V1a and the decay direction value V2a are stored in the LUT 35a as in the second embodiment, the video data D2 closer to the ideal characteristic C1 can be output. The range of values of V1a and V2a that can be stored without increasing the storage capacity of the LUT 35a is limited.

  For example, the video data D0 and D are each expressed by 8 bits, and an 8-bit storage area is provided on the LUT 35a as an area for storing a value corresponding to one combination of the video data D0 and D. If both the values V1a and V2a are to be stored in the storage area, the size of the storage area that can be occupied by the values V1a and V2a is limited to 4 bits, for example. End up. Accordingly, the range of values that can be taken by the value V0 stored in the LUT 35a corresponding to the combination in which gradation transition occurs is a range of values that can be expressed in 8 bits (0 to 255). The range that the values V1a and V2a can take is limited to a range of values (0 to 16) that can be expressed by 4 bits.

  Therefore, for example, when the correction amount is large (when the degree of gradation transition emphasis is large) as in the case where the temperature is relatively low, the required storage capacity is reduced if an appropriate value is stored in the LUT 35a. Along with this, the circuit scale of the modulation drive processing unit also increases.

  On the other hand, the modulation drive processing unit according to the present embodiment has the following case, that is, when the amount of correction is large and an appropriate value is stored in the LUT 35a. In other cases, the LUT 35 is used, and by using the LUT 35a, the video data D2 closer to the ideal characteristic C1 can be output without increasing the circuit scale.

  Specifically, unlike the configuration using the same LUT regardless of the temperature, the modulation drive processing unit according to the present embodiment divides the temperature into a plurality of temperature ranges, regardless of the temperature. Depending on which temperature range the current temperature belongs to, it is possible to switch the LUT that the modulation processing unit refers to when the gradation transition is emphasized.

  More specifically, as shown in FIG. 8, the modulation drive processing unit 21 according to the present embodiment has substantially the same configuration as the modulation drive processing unit 21 according to the first embodiment, but instead of the LUT 35 described above. In addition, an LUT group 37 composed of LUTs corresponding to the respective temperature ranges is provided. The plurality of LUTs constituting the LUT 37 is the LUT 35 or the LUT 35a. The number of LUTs 35 and 35a may be set to any one, but one of the LUTs is the LUT 35, and the other of the LUTs is the LUT 35a. In the present embodiment, the following temperature range T1, that is, the correction amount is large, and when trying to store an appropriate value in the LUT 35a, the LUT 35 is associated with the temperature range T2 in which the necessary storage capacity increases. The LUT 35a is associated with other temperature ranges.

  In addition to the configuration of the modulation drive processing unit 21, the modulation drive processing unit 21b according to the present embodiment is provided with a temperature sensor 36 that detects the temperature of the panel 11 shown in FIG. The temperature sensor 36 may be arranged at any position as long as the temperature of the pixel PIX can be detected / estimated, but it does not affect the display and more accurately detects / estimates the temperature of the pixel PIX. Therefore, it is preferable that the pixel PIX is provided on the non-display area among the substrate on which the pixel electrode of the pixel PIX is provided, the counter substrate thereof, or the color filter.

  Further, the modulation processing unit 34b provided instead of the modulation processing unit 34 is based on the detection result of the temperature sensor 36, and at the time of gradation transition emphasis at present, among the plurality of LUTs (35, 35a,...). The LUT to be referred to is selected, and the corrected video data D2 can be output based on the value stored in the LUT.

  Further, when the selected LUT is the LUT 35a, the modulation processing unit 34b operates in the same manner as the modulation processing unit 34a according to the second embodiment, and can output the video data D2. On the other hand, when the selected LUT is the LUT 35, the video data D2 can be output by operating in the same manner as the modulation processing unit 34 according to the first embodiment.

  In the above configuration, when the detection result of the temperature sensor 36 indicates the temperature range T1, the modulation processing unit 34b refers to the LUT 35 and generates the corrected video data D2. Unlike the case where all are the LUT 35a, even if the temperature range is as follows, that is, when the correction amount is large and an appropriate value is to be stored in the LUT 35a, the LUT Inadequate correction at the time of gradation transition in the rise direction can be suppressed without increasing the storage capacity required. On the other hand, in the present embodiment, since at least one of the LUTs is the LUT 35a, the video data D2 closer to the ideal characteristic C1 can be output compared to the case where all of the LUTs are the LUT 35a. As a result, the video data D2 closer to the ideal characteristic C1 can be output without increasing the circuit scale so much, and the display quality can be improved.

  In each of the above embodiments, the case where a liquid crystal cell in a vertical alignment mode and a normally black mode is used as a display element has been described as an example. However, the present invention is not limited to this. In the case of a liquid crystal display device, generally, the greater the gradation difference, the greater the torque that must be applied to the liquid crystal molecules for response, or the greater the torque that is applied to the liquid crystal molecules during response, and the greater the travel distance, The observed response time is shortened. Therefore, in the case where the modulation processing unit generates the video data by linear interpolation, the correction becomes insufficient as the gradation difference becomes smaller, and the video data D2 generated by the interpolation with respect to the gradation transition amount is ideal. The ratio of the difference from the value of the video data D2 tends to increase. As a result, if it is a liquid crystal display device, the same effect as said each embodiment is acquired.

  Even if it is not a liquid crystal display element, the pixel response speed is relatively slow, so a large correction is necessary, and correction values (the value of the video data D before correction and the value of the video data D2 after correction) are required. If the display element changes greatly depending on the gradation transition amount, substantially the same effect can be obtained.

  In each of the above-described embodiments, the case where each member configuring the modulation drive processing unit is realized only by hardware has been described as an example. However, the present invention is not limited to this. You may implement | achieve all or one part of each member with the combination of the program for implement | achieving the function mentioned above, and the hardware (computer) which performs the program. As an example, a computer connected to the image display apparatus 1 may realize the modulation drive processing unit (21 to 21b) as a device driver used when driving the image display apparatus 1. Further, when a modulation drive processing unit is realized as a conversion board built in or externally attached to the image display device 1, and the operation of a circuit that realizes the modulation drive processing unit can be changed by rewriting a program such as firmware. By distributing a recording medium in which the software is recorded or transmitting the software via a communication path, the software is distributed, and the hardware is executed by causing the hardware to execute the software. May be operated as the modulation drive processing unit of each of the above embodiments.

  In these cases, if hardware capable of executing the above-described functions is prepared, the modulation drive processing unit according to each of the above embodiments can be realized only by causing the hardware to execute the program.

  More specifically, when implemented using software, a calculation means comprising a CPU or hardware capable of executing the above-described functions executes program code stored in a storage device such as a ROM or RAM. The modulation drive processing units 21 to 21b according to the above embodiments can be realized by controlling peripheral circuits such as an input / output circuit (not shown).

  In this case, it can also be realized by combining hardware that performs a part of the processing and the arithmetic means that executes the program code for controlling the hardware and the remaining processing. Further, even among the members described above as hardware, the hardware for performing a part of the processing and the arithmetic means for executing the program code for performing the control of the hardware and the remaining processing It can also be realized by combining them. The arithmetic means may be a single unit, or a plurality of arithmetic means connected via a bus inside the apparatus or various communication paths may execute the program code jointly.

  The program code itself that can be directly executed by the computing means, or a program as data that can be generated by a process such as decompression described later, stores the program (program code or the data) in a recording medium, A recording medium is distributed, or the program is distributed by being transmitted by a communication means for transmitting via a wired or wireless communication path, and is executed by the arithmetic means.

  In addition, when transmitting via a communication path, each transmission medium which comprises a communication path propagates the signal sequence which shows a program, and the said program is transmitted via the said communication path. Further, when transmitting the signal sequence, the transmission device may superimpose the signal sequence on the carrier by modulating the carrier with the signal sequence indicating the program. In this case, the signal sequence is restored by the receiving apparatus demodulating the carrier wave. On the other hand, when transmitting the signal sequence, the transmission device may divide and transmit the signal sequence as a digital data sequence. In this case, the receiving apparatus concatenates the received packet groups and restores the signal sequence. Further, when the transmission apparatus transmits a signal sequence, the signal sequence may be multiplexed with another signal sequence and transmitted by a method such as time division / frequency division / code division. In this case, the receiving apparatus extracts and restores individual signal sequences from the multiplexed signal sequence. In any case, the same effect can be obtained if the program can be transmitted via the communication path.

  Here, it is preferable that the recording medium for distributing the program is removable, but it does not matter whether the recording medium after distributing the program is removable. In addition, the recording medium may be rewritten (writeable), volatile, or the recording method and shape as long as a program is stored. Examples of recording media include tapes such as magnetic tapes and cassette tapes, magnetic disks such as floppy (registered trademark) disks and hard disks, CD-ROMs, magneto-optical disks (MO), mini-discs (MD) and digital A disk such as a video disk (DVD) may be mentioned. The recording medium may be a card such as an IC card or an optical card, or a semiconductor memory such as a mask ROM, EPROM, EEPROM, or flash ROM. Or the memory formed in calculating means, such as CPU, may be sufficient.

  The program code may be a code for instructing the arithmetic means of all the procedures of the processes, or a basic program capable of executing a part or all of the processes by calling according to a predetermined procedure. If (for example, an operating system or a library) already exists, a part or all of the entire procedure may be replaced with a code or a pointer that instructs the arithmetic means to call the basic program.

  The format for storing the program in the recording medium may be a storage format that can be accessed and executed by the arithmetic means, for example, as in a state where the program is stored in the real memory, or is stored in the real memory. Installed in the local recording medium from the storage format after being installed in a local recording medium (for example, real memory or hard disk) that is always accessible by the computing means, or from a network or a transportable recording medium The previous storage format may be used. Further, the program is not limited to the compiled object code, but may be stored as source code or intermediate code generated during interpretation or compilation. In any case, the above calculation is performed by a process such as decompression of compressed information, decoding of encoded information, interpretation, compilation, linking, allocation to real memory, or a combination of processes. If the means can be converted into an executable format, the same effect can be obtained regardless of the format in which the program is stored in the recording medium.

  As described above, the video data processing apparatus (for example, the signal processing units 21 and 21a to 21b) according to any one of the above-described embodiments can repeatedly input video data indicating the gradation of a certain pixel. Based on the video data storage device (for example, the frame memory 31) to be stored until the next time, the previous video data read from the video data storage device, and the current video data, from the gradation indicated by the previous video data, Correction means capable of outputting post-correction video data corrected to emphasize gradation transition to the gradation indicated by the current video data, and the correction means can take the previous and current video data. Of the combinations of values, parameters for determining corrected video data corresponding to the combinations are stored corresponding to some predetermined combinations. The difference between the gradations indicated by the parameter storage device (for example, LUT 35, 35a, etc.) and the input video data exceeds a predetermined threshold value, and is a combination of the values of the video data. If the parameter corresponding to the input combination is not stored in the parameter storage device, a plurality of parameters are read from the parameter storage device, and the parameter corresponding to the input combination is calculated by interpolation based on these parameters. Then, the corrected video data is generated, and when the threshold value is not exceeded, an interpolation means (for example, modulation processing units 34 and 34a to 34b) that outputs the current video data without correction is provided. The parameter storage device constitutes a combination of the predetermined combinations. As a parameter corresponding to a specific combination in which the gradations indicated by the values are the same as each other, the gradation indicated by the corrected video data determined by the parameters is any of the gradations indicated by the values constituting the specific combination. In addition, a parameter for calculating a parameter corresponding to the input combination by the interpolation calculation when the difference between the gradations indicated by the values constituting the input combination exceeds the threshold is stored. It is characterized by.

  In the above configuration, when the difference between gradations indicated by the input video data exceeds a predetermined threshold, the video data processing apparatus can output corrected video data in which gradation transition is emphasized. Therefore, the response speed of the pixels of the display device that displays the video data can be improved.

  In addition, the interpolation means does not perform gradation transition enhancement when the amount of gradation transition does not exceed the threshold value. Therefore, for example, in the case of displaying a still image, for example, noise is displayed. It is possible to emphasize the gradation transition that occurs slightly due to the influence of the above, and to prevent the occurrence of the problem that the unwanted gradation transition is visually recognized by the user.

  Furthermore, the parameter storage device stores only the parameters corresponding to a part of the combinations of values that can be taken by the current and previous video data, and the parameters corresponding to the remaining combinations are calculated by interpolation. Therefore, the circuit scale can be greatly reduced as compared with storing parameters corresponding to all combinations in the parameter storage device.

  Further, in the parameter storage device, corresponding to the specific combination, the following parameters, that is, the gradations indicated by the corrected video data determined by the parameters are the levels indicated by the values constituting the specific combination. Stores a parameter for calculating a parameter corresponding to the input combination by the interpolation calculation when the difference between the gradations indicated by the values constituting the input combination exceeds the threshold value. Has been. Therefore, in response to a specific combination in which no gradation transition occurs, an error caused by approximation using interpolation calculation is compared with a configuration in which any of the gradations indicated by the values constituting the specific combination is stored. The display quality when displayed on the display device can be improved.

  As a result, it is possible to realize a display device that balances reduction in circuit scale and improvement in display quality at a higher level.

  In addition, when the parameters as described above are stored corresponding to the specific combination, if an interpolation calculation is used when the amount of gradation transition is equal to or less than the threshold, an error caused by approximation using the interpolation calculation May become large. However, the interpolation means does not perform gradation transition enhancement when the amount of gradation transition does not exceed the threshold value. Therefore, when the amount of gradation transition is equal to or less than the threshold value, the error does not occur, and display quality deterioration due to the error can be prevented.

  In addition to the above-described configuration, the parameter storage device may include a parameter corresponding to the specific combination of the current video data that has been input, rather than the first gradation indicated by the previous video data that has been input. A first parameter when the second gradation shown is brighter and a second parameter when the second gradation is dark, and the interpolation means reads the parameter corresponding to the specific combination from the parameter storage device when the second parameter is read out from the parameter storage device. If the second gradation is brighter than one gradation, the first parameter may be read, and if the second gradation is dark, the second parameter may be read.

  In this configuration, since two parameters are stored corresponding to the specific combination, both the gradation transition in which the pixel brightness increases and the gradation transition in which the pixel brightness decreases In comparison with the following configuration, that is, the configuration storing one of the gradations indicated by the values constituting the specific combination corresponding to the specific combination in which no gradation transition occurs, the interpolation calculation is used. Errors due to approximation can be reduced, and display quality can be improved.

  Further, in addition to the above configuration, each parameter indicates the gradation of the corrected video data, and the first and second parameters include the gradation indicated by the current video data and the corrected video as the parameter. The interpolation means indicates a difference from the gradation indicated by the data, and the interpolation means reads the first or second parameter based on the first or second parameter and the current video data. Parameters corresponding to a specific combination may be restored.

  In this configuration, each parameter indicates the gradation of the corrected video data, and the first and second parameters are stored as difference values. Here, when the first and second parameters are stored, that is, when only a small amount of gradation transition occurs, correction is performed as compared with the case where a larger amount of gradation transition occurs. The difference between the later video data and the previous and current video data is small. Therefore, a parameter necessary for storing the first and second parameters is stored by storing not the parameter indicating the corrected video data but the parameter indicating the difference between the corrected video data and the previous or current video data. The size of the area can be reduced. As a result, the circuit scale of the video data processing apparatus can be reduced as compared with the case where the corrected video data itself is stored as the first and second parameters.

  On the other hand, in the video data processing apparatus according to the present invention, in addition to the above configuration, each parameter indicates the gradation of the corrected video data, and the parameter storage device corresponds to the specific combination. As a parameter to be determined, the second gradation indicated by the input current video data is brighter or darker than the first gradation indicated by the previous input video data. Only when the parameters are stored, the interpolation means reads the parameters from the parameter storage device when the parameters corresponding to the specific combination are acquired in the predetermined case, otherwise The current video data is used as a parameter corresponding to the specific combination.

  In the configuration, when the second gradation indicated by the input current video data is brighter or darker than the predetermined one, the current video data is not included in the specific combination. Is used as a parameter corresponding to. Therefore, in both cases, the appropriate parameters are different from each other. When the other parameter is used as one parameter, the display quality is lower than when the value indicating the current video data is used as the parameter. Even so, the degree of deterioration in display quality is stored in one of the following configurations, that is, one of the gradations indicated by the values constituting the specific combination corresponding to the specific combination in which no gradation transition occurs. It can be maintained as well as the configuration. As a result, it is possible to improve the display quality on the other side while suppressing the deterioration of the display quality on one side in both cases.

  In addition, as described above, the display device driving device (for example, the image display devices 1 and 1a to 1b) according to any one of the above-described embodiments is repeatedly input, and an image showing the gradation of a certain pixel. Correction means for correcting and outputting data (for example, signal processing units 21 and 21a to 21b) and output means for outputting a signal corresponding to the corrected video data to a data signal line connected to the pixel (for example, , The data signal line driving circuit 3 and the like), and the video data before correction that has been repeatedly input is D (n−1) and D (n), and the corresponding corrected video data When the video data is D2 (n−1) and D2 (n), the correction means performs the correction after the correction when the gradation transition amount of the video data before correction is larger than a predetermined threshold L. As video data D2 (n) 2 (n) = α + k · [(D (n−1) −D (n)]), and when the gradation transition amount of the video data before correction is less than the threshold L, the correction means As corrected video data D2 (n), D2 (n) = D (n) is output, and α is set to a value different from D (n).

  In this configuration, when the gradation transition amount of the video data before correction is larger than a predetermined threshold L, the corrected video data D2 (n) is D2 (n) = α + k · [(D (n -1) -D (n)] is output, and when the gradation transition amount of the video data before correction is less than the threshold value L, D2 (n) = D as the video data D2 (n) after correction. (N) is output, and α is set to a value different from D (n).

  Therefore, in the same manner as the video data processing apparatus, the following configuration, that is, the configuration storing one of the gradations indicated by the values constituting the specific combination corresponding to the specific combination where the gradation transition does not occur is compared. Thus, errors due to approximation using interpolation calculation can be reduced, and display quality when displayed on a display device can be improved. As a result, it is possible to realize a display device that balances reduction in circuit scale and improvement in display quality at a higher level.

  Further, the liquid crystal display device according to any of the above embodiments (for example, the image display devices 1 and 1a to 1b) includes any one of the video data processing devices having the above-described configuration and the corrected data from the video data processing device. The liquid crystal display panel (for example, panel 11 etc.) driven by video data is provided. Therefore, like the video data processing device, the display quality can be improved without increasing the circuit scale so much, and the reduction in the circuit size and the improvement in the display quality are balanced at a higher level. Can be realized.

  In addition to the above configuration, the liquid crystal display device may be a television broadcast receiver or a liquid crystal monitor device. As described above, the liquid crystal display device having the video data processing device can balance reduction in circuit scale and improvement in display quality at a higher level. Therefore, it can be suitably used as a television broadcast receiver or a liquid crystal monitor device.

  By the way, the video data processing apparatus may be realized by hardware or may be realized by causing a computer to execute a program. Specifically, the program according to the present invention is a program that causes a computer having each storage device constituting any one of the video data processing devices to operate as each means constituting the video data processing device. The program is recorded on the recording medium.

  When these programs are executed by a computer, the computer operates as the video data processing device. Therefore, like the video data processing apparatus, the display quality can be improved without increasing the circuit scale so much, and a display apparatus that balances the reduction of the circuit scale and the improvement of the display quality at a higher level. Can be realized.

  It should be noted that the specific embodiments or examples made in the detailed description section of the invention are merely to clarify the technical contents of the present invention, and are limited to such specific examples in a narrow sense. It should not be construed, and various modifications may be made within the spirit of the present invention and the scope of the following claims.

  According to the present invention, it is possible to reduce an error caused by approximation using interpolation calculation when there is almost no gradation transition without increasing the circuit scale so much. A display device balanced at a higher level can be realized. Therefore, for example, it can be widely used as a video data processing device for various display devices including a video data processing device provided in a liquid crystal television receiver or a liquid crystal monitor device.

Claims (10)

A video data storage device that stores repeatedly input video data indicating the gradation of a certain pixel until the next time;
Based on the previous video data read from the video data storage device and the current video data, the gradation transition from the gray level indicated by the previous video data to the gray level indicated by the current video data is emphasized. Correction means capable of outputting corrected video data after correction,
The correction means has a parameter for determining corrected video data corresponding to a predetermined combination among a predetermined combination of values of the previous and current video data. A stored parameter storage device; and
The difference between the gradations indicated by the input video data exceeds a predetermined threshold, and a parameter corresponding to the input combination that is a combination of the values of the video data is stored in the parameter storage device. If not stored, a plurality of parameters are read out from the parameter storage device, the parameters corresponding to the input combinations are calculated by interpolation based on these parameters, and the corrected video data is generated. If it does not exceed, it is equipped with interpolation means to output the current video data without correction,
The parameter storage device includes a correction determined by the parameter as a parameter corresponding to a specific combination in which the gradations indicated by the values constituting the combination are the same among the predetermined combinations. When the gradation indicated by the post-video data is not one of the gradations indicated by the values constituting the specific combination, and the difference between the gradations indicated by the values constituting the input combination exceeds the threshold value. A video data processing apparatus, wherein parameters for calculating a parameter corresponding to the input combination by the interpolation calculation are stored. In the parameter storage device, as the parameter corresponding to the specific combination, the second gradation indicated by the inputted current video data is more than the first gradation indicated by the inputted previous video data. A first parameter for bright and a second parameter for dark,
The interpolation means reads the first parameter when the parameter corresponding to the specific combination is read from the parameter storage device, when the second gradation is brighter than the first gradation, and when the second gradation is dark, 2. The video data processing apparatus according to claim 1, wherein the second parameter is read out. Each parameter indicates the gradation of the corrected video data, and the first and second parameters are the gradation indicated by the current video data and the gradation indicated by the corrected video data as the parameter. Showing the difference,
When the first or second parameter is read, the interpolation means restores a parameter corresponding to the specific combination based on the first or second parameter and the current video data. The video data processing apparatus according to claim 2. Each of the above parameters indicates the gradation of the corrected video data,
In the parameter storage device, as a parameter corresponding to the specific combination, the second gradation indicated by the inputted current video data is more than the first gradation indicated by the inputted previous video data. Only the predetermined parameters are stored between when the light is bright and dark,
When the interpolation means obtains the parameters corresponding to the specific combination, the parameter is read from the parameter storage device if the predetermined is determined; otherwise, the current video data is converted into the specific combination. 2. The video data processing apparatus according to claim 1, wherein the video data processing apparatus is used as a corresponding parameter. A drive device for a display device including the video data processing device according to claim 1,
A signal corresponding to the video data after correction look including output means for outputting the data signal line connected to the pixel,
When the video data before correction that is repeatedly input is D (n-1) and D (n) and the corresponding video data after correction is D2 (n-1) and D2 (n) ,
When the gradation transition amount of the video data before correction is larger than a predetermined threshold L, the correction means, as the corrected video data D2 (n),
D2 (n) = α + k · [(D (n) −D (n−1)) is output,
When the gradation transition amount of the uncorrected video data is less than the threshold value L, the correcting means, as the corrected video data D2 (n),
D2 (n) = D (n) is output and
The drive device for a display device, wherein α is set to a value different from D (n). A driving method of a display device including the video data processing device according to claim 1,
A correction step of correcting and outputting video data indicating the gradation of a certain pixel that is repeatedly input;
A signal corresponding to the video data after correction look including an output step of outputting to the data signal line connected to the pixel,
When the video data before correction that is repeatedly input is D (n−1) and D (n) and the corresponding video data after correction is D2 (n−1) and D2 (n). ,
When the corrected video data D2 (n) in the correction process has a gradation transition amount of the video data before correction larger than a predetermined threshold L,
D2 (n) = α + k · [(D (n) −D (n−1)),
When the gradation transition amount of the video data before correction is less than the threshold value L,
D2 (n) = D (n),
The method for driving a display device, wherein α is set to a value different from D (n). The video data processing device according to any one of claims 1 to 4 ,
A liquid crystal display device comprising: a liquid crystal display panel driven by corrected video data from the video data processing device.   8. The liquid crystal display device according to claim 7, wherein the liquid crystal display device is a liquid crystal television receiver or a liquid crystal monitor device. A program that causes a computer having each storage device according to any one of claims 1 to 4 to operate as each unit according to the claim.   A computer-readable recording medium on which the program according to claim 9 is recorded.

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