JP4942808B2 - Display device and luminance unevenness correction method for display device - Google Patents

Description

  The present invention relates to a technique for correcting luminance unevenness on a display screen of a display device.

  In an image display device such as a liquid crystal display device, a plasma display, or an organic EL display, the brightness unevenness in which the display brightness on the screen is locally darker or brighter than the desired brightness due to various reasons in the manufacturing process. May occur.

  Brightness unevenness is classified into several types according to its shape, but typical ones are streaky unevenness that causes streaky luminance unevenness on the display screen, and spots that cause uneven brightness unevenness locally. There is unevenness.

  For example, in the manufacturing process of small high-definition liquid crystal panels, after depositing amorphous silicon on a glass substrate, laser irradiation is used to crystallize amorphous silicon with low mobility and change it to polysilicon with high mobility. If the intensity distribution of the laser is uneven, the polysilicon characteristics are uneven along the laser scanning direction, causing streaky unevenness. In addition, various parasitic capacitances exist in the display device, and stripe-like unevenness may occur due to variations in the parasitic capacitance value for each line such as a signal line.

  In addition, for example, the spot-like unevenness includes, for example, that the cell thickness of the display panel is locally different from the surroundings, the TFT characteristics are locally different, the electrode pattern dimensions are locally different, and alignment film pinholes are locally present It is caused by a cause such as contaminated foreign matter being locally mixed.

  As a method of correcting the luminance unevenness, for example, in Patent Document 1, in order to correct the luminance unevenness caused by the difference in the amount of light emitted from the backlight according to the distance from the backlight in the liquid crystal display device, It is described that luminance unevenness is corrected by multiplying a video signal by a coefficient corresponding to the distance from the backlight.

JP 2000-253277 A (published on September 14, 2000)

  However, the technique disclosed in Patent Document 1 requires the provision of a multiplier and a bit compression circuit, which causes a problem that the circuit configuration is complicated and the circuit scale is increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a display device and a luminance unevenness correction method capable of appropriately correcting the luminance unevenness of the display device with a simple configuration. is there.

  In order to solve the above problems, the display device of the present invention corrects luminance unevenness of the display screen for the display screen for displaying an image corresponding to the display image data and the display image data. And a drive control unit that controls the display state of each pixel of the display screen based on the display image data after the correction process, wherein the drive control unit The gradation correction value of each pixel in the correction data indicating the gradation correction value for correcting luminance unevenness for each pixel is added to or subtracted from the luminance value of the pixel of the display image data corresponding to each pixel. Thus, an addition / subtraction unit for performing the above-described correction processing is provided.

  Further, in order to solve the above-described problem, the brightness unevenness correction method for a display device according to the present invention includes a display screen for displaying an image corresponding to display image data, and the display for the display image data. The display screen in a display device including a drive control unit that performs a correction process for correcting luminance unevenness of the screen and controls a display state of each pixel of the display screen based on display image data after the correction process In the luminance unevenness correction method, the gradation correction value for each pixel in the correction data indicating the gradation correction value for correcting the luminance unevenness for each pixel is used as the display image data corresponding to the pixel. And an addition / subtraction step for performing the above-described correction processing by adding or subtracting the luminance value of the pixel.

  According to the display device and the luminance unevenness correction method described above, the gradation correction value of each pixel in the correction data indicating the gradation correction value for correcting the luminance unevenness for each pixel is the display image corresponding to the pixel. The display image data is corrected by adding to or subtracting from the luminance value of the data pixel. As a result, it is not necessary to provide a multiplier or a bit compression circuit as compared with the conventional technique described above, so that the circuit scale can be greatly reduced and the manufacturing cost can be greatly reduced.

  Further, the addition / subtraction unit is configured such that the display image data and the correction data are input in series for each pixel, and the luminance value of each pixel of the display image data input in series is set. On the other hand, the gradation correction value of the pixel of the correction data corresponding to each pixel may be sequentially added or subtracted pixel by pixel.

  According to the above configuration, the display image data correction process can be realized by an addition / subtraction unit having a simpler configuration.

  The display screen is arranged such that a large number of scanning signal lines arranged in parallel with each other and a large number of data signal lines arranged in parallel with each other intersect, and the display signal line includes the scanning signal lines and the data signal lines. A pixel is provided at each intersection, and the display image data for one frame is stored, and the stored display image data is stored in each pixel corresponding to one scanning signal line of the display screen or one scanning signal line. Each of the corresponding pixels is divided into groups each including a plurality of pixels, and a RAM that outputs the data in parallel for each group. The display image data for each pixel that corresponds to one scanning signal line of the display screen that is output from the RAM is 1 A parallel input serial output type shift register that outputs pixels in series, and the adder / subtractor outputs each of the display image data output in series from the shift register one pixel at a time. The luminance value of the unit, the gradation correction value of the correction data pixels corresponding to the respective pixels sequentially one by one pixel may be configured to add or subtract.

  In a configuration including a RAM (so-called frame buffer) that stores the display image data for one frame, the output from the RAM is generally composed of a plurality of pixels for each scanning signal line (or each pixel on one scanning signal line). Are output in parallel for each group divided into groups). On the other hand, in the above configuration, display image data output in parallel from the RAM for each scanning signal line (or each group) is input, and the input display image data is input to the adder / subtractor. A parallel input serial output type shift register that outputs pixels one by one in series is provided. As a result, the addition / subtraction unit sequentially adds or subtracts the gradation correction value of the pixel of the correction data corresponding to each pixel one by one with respect to the luminance value of each pixel of the display image data input in series. can do. Therefore, a RAM is provided that outputs the display image data in parallel for each pixel corresponding to one scanning signal line of the display screen or for each group obtained by dividing each pixel corresponding to one scanning signal line into a group consisting of a plurality of pixels. Even with the configuration, the correction process can be performed by an addition / subtraction unit having a simple configuration.

  The display screen is arranged such that a large number of scanning signal lines arranged in parallel with each other and a large number of data signal lines arranged in parallel with each other intersect, and the display signal line includes the scanning signal lines and the data signal lines. A pixel is provided for each intersection, the display image data for one frame subjected to the correction processing by the addition / subtraction unit is stored, and the stored display image data is stored in one scanning signal line of the display screen. RAM that outputs each pixel corresponding to one or each pixel corresponding to one scanning signal line into a group composed of a plurality of pixels in parallel, and the correction processing is performed by the adder / subtractor and stored in the RAM An inverse conversion processing unit that performs reverse processing of the correction processing on the display image data that has been displayed and restores the display image data before the correction processing is performed, and the reverse conversion processing. A frame comparison unit that compares the restored display image data with the display image data of the second frame that is a frame to be displayed next to the display image data stored in the RAM. The addition / subtraction unit is for displaying the second frame when the frame comparison unit determines that the display image data restored by the inverse transformation process is different from the display image data for the second frame. The correction processing is performed by adding or subtracting the gradation correction value of the pixel of the correction data corresponding to each pixel to the luminance value of each pixel of the image data, and one frame worth stored in the RAM While updating the display image data to the display image data after the correction process, the display image data and the second frame restored by the inverse conversion process It may be configured to not update the display image data to be stored in the RAM in the case of the frame comparing section and display image data and are the same is determined.

  According to the above configuration, the inverse conversion processing unit performs the inverse conversion process on the display image data after the correction process stored in the RAM to restore the display image data before the correction process. As a result, display image data for the current frame (display image data obtained by performing reverse conversion on the display image data stored in the RAM) and display for the next frame (second frame) in the frame comparison unit. When comparing with image data, it is possible to compare display image data that has not been subjected to correction processing. Therefore, it is possible to appropriately determine whether or not the display image data for the current frame and the display image data for the next frame are the same. In addition, since the display image data and the correction data before being stored in the RAM are each input in series in the adder / subtracter, the luminance value of each pixel of the display image data input in series is calculated. Correction processing can be performed by sequentially adding or subtracting gradation correction values of pixels of correction data corresponding to the respective pixels one by one. Therefore, the correction process can be performed with a simple configuration.

  The display screen is arranged such that a large number of scanning signal lines arranged in parallel with each other and a large number of data signal lines arranged in parallel with each other intersect, and the display signal line includes the scanning signal lines and the data signal lines. A pixel is provided at each intersection, and the display image data for one frame is stored, and the stored display image data is stored in each pixel corresponding to one scanning signal line of the display screen or one scanning signal line. A RAM that outputs each corresponding pixel into a group of pixels and outputs the correction data in parallel for each group, and the correction data that is input in series for each pixel for each pixel corresponding to one scanning signal line on the display screen And a serial input parallel output type shift register that outputs in parallel for each pixel corresponding to the above, and the adder / subtractor inputs in parallel for each pixel corresponding to one scanning signal line of the display screen from the RAM Gradation correction of pixels corresponding to each pixel in correction data inputted in parallel for each pixel corresponding to one scanning signal line of the display screen from the shift register for each pixel of the display image data It is good also as a structure which adds or subtracts a value in parallel.

  According to the above configuration, the addition or subtraction process for each pixel corresponding to one scanning signal line is performed in parallel, so that the processing time can be shortened. Further, the adder / subtractor described above can be realized simply by including an adder / subtracter corresponding to the number of pixels corresponding to one scanning signal line, and therefore, it is necessary to include a multiplier and a bit compressor as in the above-described prior art. The display image data can be corrected with a simple configuration.

  The drive control unit is an area in which an image having a luminance value different from an appropriate luminance value corresponding to the inspection image data is displayed when an image corresponding to the inspection image data is displayed on the display screen. To reduce the difference between the luminance value when displaying an image corresponding to the display image data and the appropriate luminance value corresponding to the display image data for at least a part of the luminance uneven region. In addition, for correcting the gradation values of the pixels included in the correction area, which is an area corresponding to the at least some luminance unevenness area in the display image data or an area including the luminance unevenness area and its peripheral area. When a correction data generation data storage unit for storing correction data generation data used for generation of correction data and an image corresponding to the display image data are displayed on the display screen Correction for generating the correction data for correcting the display image data so as to change the gradation values of at least some of the pixels included in the correction area based on the correction data generation data A data generation unit, and the addition / subtraction unit adds the gradation correction value of each pixel in the correction data generated by the correction data generation unit to the luminance value of the pixel of the display image data corresponding to the pixel. Or it is good also as a structure which subtracts.

  According to the above configuration, the correction data is created according to the occurrence state of the brightness unevenness when the image corresponding to the inspection image data is displayed on the display screen, and the brightness unevenness correction processing is performed according to the created correction data. It can be performed. Thereby, luminance unevenness can be corrected appropriately.

  The display screen is arranged such that a large number of scanning signal lines arranged in parallel with each other and a large number of data signal lines arranged in parallel with each other intersect, and the display signal line includes the scanning signal lines and the data signal lines. A pixel is provided at each intersection, and the correction data generation data storage unit corrects streaky luminance unevenness that extends in a direction parallel to the direction in which the data signal lines extend on the display screen. A first correction data generation data storage unit for storing first correction data generation data used for generating the first correction data for correcting the spot-like luminance unevenness locally present on the display screen A second correction data generation data storage unit for storing second correction data generation data used for generating the second correction data, and the correction data generation unit responds to the display image data. When displaying the image on the display screen, based on the first correction data generation data, the gradation of at least some of the pixels included in the correction area corresponding to the stripe-shaped luminance unevenness A first correction data generating unit that generates the first correction data for correcting the display image data so as to change the value; and an image corresponding to the display image data is displayed on the display screen. Based on the second correction data generation data, the display image data so as to change the gradation values of at least some of the pixels included in the correction region corresponding to the spot-like luminance unevenness. A second correction data generating unit that generates the second correction data for correcting the first correction data, and an integrated processing unit that generates integrated correction data obtained by integrating the first correction data and the second correction data. The addition / subtraction unit performs the correction process by adding or subtracting the gradation correction value of each pixel in the integrated correction data to the luminance value of the pixel of the display image data corresponding to the pixel. It is good also as a structure.

  According to the above configuration, streaky luminance unevenness and spotted luminance unevenness can be corrected with a simple circuit. A first correction data generating unit that generates first correction data for correcting streaky luminance unevenness; and a second correction data generating unit that generates second correction data for correcting speckled luminance unevenness; Are separately provided, the first correction data and the second correction data can be created by an algorithm corresponding to the characteristic of each luminance unevenness.

  In addition, the drive control unit may include an average value, a maximum value, a minimum value, an intermediate value between the maximum value and the minimum value of pixels included in the correction area in the display image data, or the correction area. Any one of the average value, the maximum value, the minimum value, and the intermediate value between the maximum value and the minimum value of the gradation values of some of the included pixels, a predetermined upper limit value, and When any one of the values is equal to or higher than the upper limit and when any one of the values is equal to or lower than the lower limit, it belongs to the correction region in the display image data. A configuration in which the gradation value of the pixel is not corrected may be employed.

  The drive control unit compares a gradation value of each pixel included in the correction area in the display image data with a predetermined upper limit value and lower limit value, and the gradation value is equal to or higher than the upper limit value. It is also possible to adopt a configuration in which the gradation value is not corrected for pixels that are and pixels that are equal to or lower than the lower limit value.

  Generally, luminance unevenness is easy to see when displaying a halftone image (particularly a dark gray image), and when displaying a white image (or an image close to white) or a black image (or an image close to black). Since it is relatively difficult to visually recognize the image, if the luminance unevenness correction process is performed on the white image or the black image, the corrected area is visually unnaturally displayed. On the other hand, according to each configuration described above, it is possible to prevent the region corrected by the luminance unevenness correction process from being unnaturally viewed.

  The correction data generation unit selects some of the pixels included in the correction area as adjustment correction pixels, and adjusts the correction amount of the gradation value for the adjustment correction pixel in the correction area. It is also possible to adopt a configuration in which the gradation value correction amount for pixels other than the pixels is different.

  According to the above configuration, the luminance value of all the pixels in the correction area of the image to be viewed is less than the luminance value corresponding to one gradation of the display image data (or the floor portion of the display image data is not zero). (A luminance value corresponding to a tone value) can be brought close to an image when it is uniformly changed. That is, the luminance value of all the pixels in the correction area is less than the luminance value corresponding to one gradation of the display image data (or the luminance value corresponding to the gradation value in which the decimal part of the display image data is not 0). Can only be corrected. Therefore, it is possible to more appropriately prevent the luminance unevenness from being visually recognized.

  For example, some medium-sized and small-sized display devices provided in portable electronic devices and the like perform display using 6-bit video signals for each color of RGB. In these display devices, luminance between gradations in the video signal is determined. The width of the value is larger than that of a display device such as 8 bits for each color of RGB. For this reason, in many cases, the magnitude of the correction value for correcting the luminance unevenness is less than a value corresponding to one gradation of the video signal, and the gradation correction value in the correction region is uniform as in the prior art. However, the luminance unevenness cannot be appropriately corrected due to insufficient correction amount or too much correction amount. On the other hand, according to the above configuration, the image to be visually recognized is less than the luminance value corresponding to one gradation for each pixel in the correction area (or the gradation value in which the decimal part of the display image data is not 0). (Brightness value corresponding to) can be made close to the image when it is uniformly changed, so that uneven brightness can be corrected more appropriately.

  The correction data creation unit may be configured to select the adjustment correction pixels so that the adjustment correction pixels are dispersed in the correction area without being densely arranged.

  According to the above configuration, by distributing the positions of the adjustment correction pixels in the correction area, the luminance value of all the pixels in the correction area corresponding to one gradation of the display image data is displayed in the image to be viewed. It can be made closer to the case where it is uniformly corrected by less than the value (or the luminance value corresponding to the gradation value in which the decimal part of the display image data is not 0).

  Further, the correction data creation unit may be configured to change a pixel selected as the adjustment correction pixel every predetermined period in the correction area.

  According to the above configuration, by changing the position of the adjustment correction pixel in the correction area every predetermined period, the luminance value of all the pixels in the correction area is set to one gradation of the display image data. It can be made closer to the case where it is uniformly corrected by less than the luminance value corresponding to (or the luminance value corresponding to the gradation value in which the decimal part of the display image data is not 0).

  As described above, in the display device of the present invention, the drive control unit calculates the gradation correction value of each pixel in the correction data indicating the gradation correction value for correcting the luminance unevenness for each pixel. An addition / subtraction unit that performs the correction process by adding or subtracting the luminance value of the pixel of the display image data corresponding to the pixel is provided.

  Further, in the luminance unevenness correction method for a display device according to the present invention, the gradation correction value of each pixel in the correction data indicating the gradation correction value for correcting the luminance unevenness for each pixel corresponds to the pixel. It includes an addition / subtraction step for performing the correction process by adding or subtracting the luminance value of the pixel of the display image data.

  Therefore, since it is not necessary to provide a multiplier or a bit compression circuit, the circuit scale can be greatly reduced, and the manufacturing cost can be greatly reduced.

It is a block diagram which shows the structure of the drive control part with which the display apparatus concerning one Embodiment of this invention is equipped. It is a block diagram which shows the structure of the correction data production apparatus which produces | generates the correction data for correct | amending the brightness nonuniformity in this display apparatus and this display apparatus. FIG. 3 is a graph showing an example of luminance data extracted from imaging data and a moving average value calculated from the luminance data in the correction data creation apparatus shown in FIG. 2. FIG. 4 is a graph showing luminance data obtained by removing the influence of slowly varying luminance unevenness such as luminance unevenness caused by a backlight from the luminance data shown in FIG. 3 and an average luminance of a display screen. It is explanatory drawing for demonstrating the production | generation method of the correction data in the correction data production apparatus shown in FIG. It is explanatory drawing for demonstrating the production | generation method of the correction data in the correction data production apparatus shown in FIG. It is explanatory drawing which shows an example of the correction pixel (adjustment correction pixel) and the pixel which is not correct | amended (pixels other than an adjustment correction pixel) in the correction data produced | generated in the correction data production apparatus shown in FIG. It is explanatory drawing which shows the concept of the approximation to the circular area | region of the brightness nonuniformity area | region in the correction data production apparatus shown in FIG. (A) And (b) is explanatory drawing which shows an example of the correction pattern set in the drive control part shown in FIG. It is explanatory drawing which shows an example of the correction pattern set in the drive control part shown in FIG. It is explanatory drawing which shows the correction method of the image data in the display apparatus shown in FIG. (A) And (b) is explanatory drawing which shows an example of the correction pattern set in the drive control part shown in FIG. It is explanatory drawing which shows an example of the setting method of the correction pattern in the drive control part shown in FIG. It is explanatory drawing which shows an example of the setting method of the correction pattern in the drive control part shown in FIG. It is a graph which shows the brightness | luminance data before and behind a brightness nonuniformity correction process. It is a block diagram which shows the structure of the drive control part with which the display apparatus concerning other embodiment of this invention is equipped. It is a block diagram which shows the structure of the drive control part with which the display apparatus concerning further another embodiment of this invention is equipped. It is a block diagram which shows the structure of the drive control part with which the display apparatus concerning further another embodiment of this invention is equipped.

Embodiment 1
An embodiment of the present invention will be described. In the present embodiment, a source in a transmissive liquid crystal display device provided in a mobile device such as a mobile phone, which displays based on image data expressing each color of RGB in 6 bits. An example in the case of correcting streaky luminance unevenness (streaky unevenness) in a direction parallel to the extending direction of the line (data signal line) and local spotted luminance unevenness (spotted unevenness) will be mainly described. . That is, in the present embodiment, a large number of gate lines (scanning signal lines) arranged in parallel to each other and a large number of source lines arranged in parallel to each other intersect, and the gate lines, the source lines, In a display device having a configuration in which a pixel is provided at each intersection, an example of correcting streaky luminance unevenness in a direction parallel to the extending direction of the source line and local spotted luminance unevenness will be described. .

  FIG. 2 is a block diagram illustrating the configuration of the correction data generation data creation device 10 and the display device 20 according to the present embodiment. In the present embodiment, correction data generation data is generated based on the result of imaging the display screen of the display device 20 in a state where the correction data generation data generation device 10 displays an image corresponding to the inspection image data. . More specifically, the correction data generation data creation device 10 uses the display device 20 to generate first correction data for use in generating first correction data for correcting streak-like unevenness, and the display device 20. The second correction data generation data used when generating the second correction data for correcting the spot-like unevenness in FIG. The display device 20 stores the correction data generation data, and displays the first correction data and the second correction data based on the correction data generation data when displaying an image corresponding to the display image data. Data is generated, and the display image data is corrected based on both the correction data and displayed.

(1-1. Correction Data Generation Data Creation Device 10)
First, the correction data generation data creation device 10 will be described. As illustrated in FIG. 2, the correction data generation data generation device 10 includes a display data generation unit 11, an imaging unit 12, a luminance data extraction unit 13, a first moving average processing unit 14, and a first luminance unevenness detection unit 15. , A first correction data generation data generation unit 16, a second moving average processing unit 14b, a second luminance unevenness detection unit 15b, and a second correction data generation data generation unit 16b.

  The display data generation unit 11 generates inspection image data, which is display data to be displayed on the display panel when the display panel 21 is inspected for luminance unevenness, and outputs the generated image data to the drive control device 22a of the display panel 21. . In general, luminance unevenness is likely to be visually recognized when a halftone image (particularly a dark gray image) is uniformly displayed on the entire surface with the same gradation. For this reason, in the present embodiment, the display data generation unit 11 generates image data for displaying a halftone image of the same gradation on all pixels of the display panel as inspection image data in order to detect luminance unevenness. To do.

  The imaging unit 12 acquires imaging data by imaging the display surface of the display panel 21 on which an image corresponding to the inspection image data generated by the display data generation unit 11 is displayed. As the imaging unit 12, for example, a CCD camera or the like can be used.

  The luminance data extraction unit 13 extracts luminance data from the imaging data acquired by the imaging unit 12.

  The first moving average processing unit 14 is a region corresponding to each source line of the display screen in the luminance data extracted by the luminance data extracting unit 13 (or a region having a predetermined width parallel to the extending direction of the source line (for example, 2 to 2). For the line pixel group that is a set of pixels in the area of three lines)), the average value of the luminance of each pixel included in the line pixel group is calculated as the luminance value of the line pixel group. In addition, the first moving average processing unit 14 determines the luminance value of each line pixel group as a peripheral region of a predetermined range including the line pixel group (for example, the extending direction of the line pixel group centered on the line pixel group). A moving average process is performed to calculate moving average data averaged with the luminance value of each pixel included in a 3 mm wide area in a direction perpendicular to the vertical direction. Hereinafter, the luminance value of each pixel after the moving averaging process is referred to as a moving average value.

  The solid line in FIG. 3 is a graph showing the luminance value of each line pixel group calculated based on the luminance data extracted by the luminance data extraction unit 13, and the broken line shows the moving average value of the luminance value of each line pixel group. It is a graph. The above moving average value is obtained in order to remove moderate luminance unevenness such as luminance unevenness caused by the backlight and extract local luminance unevenness that is easily recognized as unevenness. Show. The solid line in FIG. 4 is obtained by adding the average value of panel luminance (average value of luminance of the entire display screen) to the value obtained by subtracting the moving average value from the luminance value of each line pixel group in FIG. It is a graph which shows the luminance value of each line pixel group after removing the influence of the luminance unevenness which changes gradually, such as the luminance unevenness resulting from light, and a broken line is a graph which shows the average value of panel luminance. In these graphs, the horizontal axis indicates the position of each line pixel group, and the vertical axis indicates the luminance value of each line pixel group (the average value of the luminance values of pixels belonging to each line pixel group).

  The first luminance unevenness detection unit 15 detects a region where the luminance unevenness occurs based on the luminance value of each line pixel group extracted from the imaging data by the luminance data extraction unit 13 and the moving average value thereof.

  Specifically, the first luminance unevenness detection unit 15 calculates and calculates the difference between the luminance value of each line pixel group in the luminance data extracted from the imaging data by the luminance data extraction unit 13 and the moving average value thereof. An area composed of a set of line pixel groups in which the absolute value of the difference is equal to or greater than a predetermined threshold is detected as luminance unevenness. In other words, the moving average value of the luminance values of each line pixel group is regarded as an appropriate luminance value when no luminance unevenness has occurred for each line pixel group, and is compared with the luminance value of each line pixel group. Detects the area where is occurring. Thereby, it is possible to appropriately detect luminance unevenness by removing the influence of the backlight and the like.

  That is, in a transmissive liquid crystal display device, a diffusion plate or the like is generally provided to uniformly irradiate the display panel with light emitted from the backlight, but it is difficult to make the display panel uniform uniformly. Depending on the position, there may be a difference in the brightness of the light emitted from the backlight. However, since the luminance distribution due to the relative position with respect to the backlight changes relatively gently over a wide range of the display panel (see the inclination of the broken line portion in FIG. 3), it is rarely recognized as luminance unevenness. In other words, it is recognized that the brightness is uneven in the human eye when the brightness is greatly changed locally, and is recognized as uneven when the brightness is continuously changing with a large spatial period. It is hard to be done. For this reason, the difference in luminance caused by the luminance distribution of the irradiation light from the backlight is rarely recognized as luminance unevenness.

  On the other hand, if the brightness value of the appropriate area where brightness unevenness does not occur without considering the influence of the backlight is regarded as a constant value for all areas of the display screen, an area that is not visually recognized as brightness unevenness may be detected as brightness unevenness. In some cases, an area that is visually recognized as luminance unevenness is detected as an appropriate area. That is, the luminance value (appropriate luminance value) of the appropriate area where the luminance unevenness does not occur differs depending on the position on the display panel.

  Therefore, in the present embodiment, the first moving average processing unit 14 performs the moving averaging process on the luminance data extracted by the luminance data extracting unit 13, and the moving average value of the luminance value of each line pixel group is set to each of the corresponding values. It is regarded as a luminance value (appropriate luminance value) when the line pixel group is an appropriate region. This eliminates the influence of the luminance distribution of the illumination light from the backlight, and appropriately and easily detects an area where the difference from the brightness of the adjacent area, which is easily visible as an uneven brightness, changes rapidly. be able to.

  Note that the range to be averaged in the moving averaging process (the range in the direction perpendicular to the extending direction of the line pixel group) is sufficiently wider than the width of the stripe-like luminance unevenness region, and the backlight at each position within the range. It is preferable to set the difference in the luminance value of the irradiation light from within a range where the luminance value in the luminance unevenness region is sufficiently small with respect to the deviation from the appropriate luminance value. Specifically, in the case of a display panel of about several hundred pixels × several hundred pixels provided in a mobile device such as a mobile phone, it is preferable to set the display panel in a range of 1 mm to 5 mm. In this embodiment, the display panel 21 of 360 pixels × 480 pixels is used, and the above range is set to 3 mm.

  The first correction data generation data generation unit 16 is based on the information on the luminance unevenness detected by the first luminance unevenness detection unit 15, and first correction data for making the display device 20 less likely to visually recognize the stripe-shaped luminance unevenness. The first correction data generation data (correction data generation data) used when generating is generated, the generated first correction data generation data is subjected to compression processing and output to the display device 20. When the difference between the peak value of the luminance value of the line pixel group included in the luminance unevenness region and the appropriate luminance value is less than a predetermined reference value, it is considered that no streaky luminance unevenness exists and the first correction data is generated. You may make it not create production data.

  In the present embodiment, as described above, the display device 20 that performs display based on image data expressing each color of RGB with 6 bits is used. In this type of low gradation panel, uneven brightness may not be corrected appropriately by simply adjusting the gradation of the display image data based on the detection result of uneven brightness. This is because the minimum value of the deviation of the luminance value recognized as luminance unevenness is less than the luminance value corresponding to one gradation in the display image data in the case of a 6-bit gradation panel. If the correction is made so that the data is increased by one gradation, the correction amount becomes too large and the brightness is visually perceived as bright luminance unevenness. This is because it may be visually recognized as unevenness.

  Therefore, the first correction data generation data generation unit 16 visually recognizes the luminance unevenness caused by the luminance deviation even if the luminance deviation with respect to the appropriate luminance value is less than the luminance value corresponding to one gradation of the image data. First correction data generation data for making it difficult to be generated is generated.

  FIG. 5 is an explanatory diagram for explaining a correction pattern generation method. More specifically, FIG. 5 displays inspection image data having gradation values 9, 10, and 11 (gradation value 0 corresponds to black and gradation value 63 corresponds to white) for each pixel, It is a graph which shows the luminance value of each line pixel group extracted based on the imaging data which imaged the display panel 21 of the state which displayed the image according to these each gradation value, and the average value of panel luminance. Note that FIG. 5 shows the luminance value of each line pixel group after performing the same processing as in FIG. 4 and removing the influence of the luminance variation that gradually changes such as the luminance variation caused by the backlight.

  The first luminance unevenness detection unit 15 detects a portion where the absolute value of the difference between the luminance values with respect to the appropriate luminance value in the luminance data extracted from the imaging data is equal to or greater than a predetermined threshold as luminance unevenness. Specifically, a portion where the difference is a positive value and the absolute value is greater than or equal to the threshold is detected as bright unevenness, and a portion where the difference is a negative value and the absolute value is greater than or equal to the threshold is determined as dark unevenness. To detect. In the example of FIG. 5, the portions indicated by C1 and C2 are detected as bright luminance unevenness, and the portions indicated by D1 and D2 are detected as dark luminance unevenness.

  Next, the first correction data generation data generation unit 16 detects a difference between the value of each luminance unevenness portion and the appropriate luminance value. In the example of FIG. 5, differences c1, c2, d1, and d2 are detected for luminance unevenness C1, C2, D1, and D2, respectively.

  In addition, the first correction data generation data generation unit 16 determines the difference A between the luminance value of the appropriate portion for the image data that is one gradation higher than the reference gradation value and the luminance value of the appropriate portion for the image data of the reference gradation value. , And the difference B between the luminance value of the appropriate part for the image data of the reference gradation value and the luminance value of the appropriate part for the image data one gradation lower than the reference gradation value.

  Then, the first correction data generation data generation unit 16 calculates the ratios c1 / B and c2 / B between the differences c1 and c2 and the difference B with respect to the luminance unevenness C1 and C2, respectively. For dark luminance unevenness D1 and D2, ratios d1 / A and d2 / A between the differences d1 and d2 and the difference A for the luminance unevenness are calculated.

  When the above ratio (c1 / B, c2 / B, etc.) for bright luminance unevenness is 1 or less, the first correction data generation data generation unit 16 belongs to the line pixel group corresponding to the bright luminance unevenness. First correction data generation data for reducing the display image data for the pixels (adjustment correction pixels) at a ratio corresponding to the ratio of the luminance unevenness among the pixels by one gradation is generated.

  When the ratio (c1 / B, c2 / B, etc.) exceeds 1, the first correction data generation data generation unit 16 displays image data for pixels belonging to the line pixel group corresponding to bright luminance unevenness. The first correction data generation data for lowering the image by the gradation value corresponding to the integer part of the ratio, and display image data for the ratio of pixels (adjustment correction pixels) corresponding to the decimal part of the ratio First correction data generation data for lowering one gradation is generated.

  FIG. 6 is a graph illustrating an example of a relationship between a position where bright luminance unevenness occurs and the value of the ratio for each luminance unevenness.

  The first correction data generation data generation unit 16 groups the luminance unevenness regions according to the ratio value. For example, as shown in FIG. 6, the luminance unevenness region having the above ratio of 0.125 or more and less than 0.375 has a correction strength of 1, the luminance unevenness region having the ratio of 0.375 or more and less than 0.625 has a correction strength of 2, Luminance unevenness area where the ratio is 0.625 or more and less than 0.875, correction intensity 3, and luminance unevenness area where the ratio is 0.875 or more and less than 1.125, correction intensity 4, and the ratio is 1.125 or more and 1.375. The luminance unevenness region less than the threshold is classified into the correction intensity 5.

  Then, regarding the luminance unevenness region with the correction intensity 1, it is assumed that the ratio is 0.25, and the first correction data generation data for reducing the gradation value by one gradation at a ratio of one pixel to four pixels is generated. To do. For example, since the value of ck / B is 0.19 at the position corresponding to ck shown in FIG. 6, it is classified as correction strength 1, and the gradation value is lowered by one gradation at a ratio of one pixel to four pixels. First correction data generation data is generated.

  In addition, regarding the luminance unevenness region with the correction strength 2, it is assumed that the above ratio is 0.5, and the first correction data generation data for reducing the gradation value by one gradation at a ratio of one pixel to two pixels is created. To do. For example, since the value of cn / B is 0.44 at the position corresponding to cn shown in FIG. 6, it is classified as correction intensity 2 and the gradation value is lowered by one gradation at a ratio of one pixel to two pixels. First correction data generation data is generated.

  In addition, regarding the luminance unevenness region with the correction intensity 3, it is assumed that the ratio is 0.75, and the first correction data generation data for reducing the gradation value by one gradation at a ratio of three pixels to four pixels is generated. To do. For example, since the value of cl / B is 0.80 at the position corresponding to cl shown in FIG. 6, it is classified as correction strength 3, and the gradation value is lowered by one gradation at a ratio of 3 pixels to 4 pixels. First correction data generation data is generated.

  Further, regarding the luminance unevenness region with the correction intensity 4, it is assumed that the ratio is 1, and the first correction data generation data for reducing the gradation value by 1 gradation is created for each pixel.

  In addition, the luminance unevenness area with the correction strength 5 is regarded as having the above ratio of 1.25, and the gradation value of each pixel is lowered by one gradation, and the gradation value is set for the ratio of one pixel to four pixels. Further, first correction data generation data for lowering one gradation (a total of two gradations) is created. For example, since the value of cm / B at the position corresponding to cm shown in FIG. 6 is 1.29, it is classified as correction intensity 5, and the gradation value of each pixel is lowered by 1 gradation and the pixel value is reduced to 4 pixels. First correction data generation data for lowering the gradation value by one gradation at a rate of one pixel is created.

  Further, when the ratio (c1 / B, c2 / B, etc.) exceeds 1, the first correction data generation data generation unit 16 has a division result of 1 or less when the ratio is divided. The above ratio may be divided by the number n, and first correction data generation data for reducing the display image data for the pixels (adjustment correction pixels) at a ratio corresponding to the division result by n gradations may be created. For example, in the case of the luminance unevenness region belonging to the correction intensity 5 shown in FIG. 6, it is assumed that the ratio is 1.25 (= 5/4), and a value obtained by dividing n = 2 (5/4 ÷ 2 = 5/8) is calculated, and first correction data generation data for reducing two gradations at a ratio of 5 pixels to 8 pixels may be created according to the division result.

  Further, when the ratio (d1 / A, d2 / A, etc.) for dark luminance unevenness is 1 or less, the first correction data generation data generation unit 16 belongs to the line pixel group corresponding to the dark luminance unevenness. First correction data generation data for increasing the display image data by one gradation for the pixels in a proportion corresponding to the ratio of the luminance unevenness among the pixels is generated.

  When the ratio (d1 / A, d2 / A, etc.) exceeds 1, the first correction data generation data generation unit 16 displays image data for pixels belonging to the line pixel group corresponding to the dark luminance unevenness. Further includes first correction data generation data for increasing the gradation value corresponding to the integer part of the ratio, and display image data for pixels (adjustment correction pixels) at a ratio corresponding to the decimal part of the ratio. First correction data generation data for increasing one gradation is generated.

  Further, when the ratio (d1 / A, d2 / A, etc.) exceeds 1, the first correction data generation data generation unit 16 has a division result of 1 or less when the ratio is divided. The above ratio may be divided by the number n, and first correction data generation data for increasing the display image data for the ratio of pixels according to the division result by n gradations may be created.

  Note that FIG. 6 does not show the case where the ratio is 1.375 or more, but also in the case where the ratio is 1.375 or more, the grouping of each luminance unevenness region and each luminance unevenness region are performed in the same manner as described above. The corresponding first correction data generation data may be created. Further, the width of the ratio corresponding to each group is not limited to the example shown in FIG.

  Therefore, for example, when the ratio is 1 or less, in the luminance uneven region where the difference from the appropriate luminance value (deviation from the appropriate luminance value) is large, the ratio of the pixels for correcting the display image data by one gradation is large ( In the luminance uneven region where the difference to the appropriate luminance value is relatively small, the ratio of the pixels for correcting the display image data by one tone is small (display pixels are densely corrected for the display image data by one tone). Pixels for correcting one gradation of image data are sparse). FIG. 7 is an explanatory diagram illustrating an example of a pixel that corrects the gradation of display image data by one gradation when the ratio in the first correction data generation data is 1 or less.

  For example, in the case of c1 / B = 1/3, the image data for the pixels on the source line corresponding to the luminance unevenness C1 in the display image data is displayed on the first floor for every three pixels along the extending direction of the source line. First correction data generation data (image data indicating the ratio of the adjustment correction pixels to the total number of pixels connected to the source line to be corrected) for correcting the low tone is generated. When d1 / A = 1/3, the image data for the pixels on the source line corresponding to the luminance unevenness D1 in the display image data is displayed on the first floor by one pixel every three pixels along the extending direction of the source line. First correction data generation data for high correction is generated.

  Note that each luminance depends on the size of the ratio ci / B (i is an integer of 1 or more indicating the position of luminance unevenness) or the ratio dj / A (j is an integer of 1 or more indicating the position of luminance unevenness). It is determined which of a plurality of preset groups the degree of brightness unevenness in the unevenness area (degree of deviation from the appropriate brightness value) belongs to, and this determination result and each group are preset. The ratio of the adjustment correction pixels in the display image data (or the interval between the adjustment correction pixels) may be set based on the value.

  In the above example, the case where the value of ci / B or dj / A and the ratio of the adjustment correction pixel are set to the same value has been described. However, the present invention is not limited to this. For example, the value of ci / B or dj / A is set in advance. You may make it set the ratio of an adjustment correction pixel based on the value which multiplied the defined correction coefficient. The correction coefficient may be set according to the gradation value of the display image data. For example, as described above, the luminance unevenness is easy to be visually recognized in the halftone, and is difficult to visually recognize in the case of a display close to black and white. Therefore, the correction coefficient in the gradation close to black and white is used. You may set larger than.

  As described above, the first correction data generation data includes, for example, the source line (position of the correction area) corresponding to the luminance unevenness, the ratio of the adjustment correction pixels in the source line (adjustment correction pixel interval), and the adjustment. It consists of information indicating whether the correction pixel should be raised or lowered by one gradation. If there is luminance unevenness with the ratio exceeding 1, the correction amount of the gradation value for each pixel included in the region corresponding to the luminance unevenness (correction for pixels other than the adjustment correction pixel) in addition to these pieces of information. Amount). Alternatively, when there is luminance unevenness with the ratio exceeding 1, the correction amount of the gradation value of the adjustment correction pixel (described above) is used instead of the information indicating whether the adjustment correction pixel is increased or decreased by one gradation. Information indicating whether to increase or decrease the gradation value of the adjustment correction pixel.

  In the above description, the first correction data generation data generation unit 16 corrects only the pixels in the detected luminance unevenness region. However, the present invention is not limited to this, and the luminance unevenness region and its peripheral region (for example, Pixels in a region including a luminance unevenness region and a range of several pixels or a few mm may be corrected. That is, the luminance unevenness region may be used as the correction region, and the region including the luminance unevenness region and its surrounding region may be used as the correction region. As described above, by including the peripheral region in the correction region, it is possible to make the luminance unevenness region less visible by blurring the outline of the luminance unevenness region.

  Further, it is not always necessary to correct all the detected luminance unevenness areas, and only a part of the detected brightness unevenness areas may be corrected. For example, it is possible to extract and correct only the luminance unevenness region that is easily visually recognized according to the size of the luminance unevenness region or the degree of deviation from the appropriate luminance value.

  The first correction data generation data generation unit 16 calculates the first correction data generation data for each of R (Red), G (Green), and B (Blue) subpixels.

  Note that first correction data generation data for one color (for example, G) of R, G, and B may be generated and shared for the other colors. In many cases, streaky luminance unevenness continuously occurs within a predetermined range, so that the first correction data generation data generated for one color of R, G, and B is used for the other colors on both sides. Even when applied to sub-pixels, the degree of image quality is almost the same as when the first correction data generation data is individually generated for each color of R, G, and B. Further, by using the common first correction data generation data for each color of R, G, and B, compared to the case where individual first correction data generation data is generated for each of these colors, the display device 20 described later is used. The storage capacity required for the first correction data generation data storage unit 31 for storing the first correction data generation data provided can be reduced.

  Thereafter, the first correction data generation data generation unit 16 performs a compression process on the generated first correction data generation data, and the first correction data generation data after the compression process is sent to the drive control device 22a of the display device 20. Output. Note that the compression processing method and the size of the first correction data generation data after compression are not particularly limited, and depend on the storage capacity of the first correction data generation data storage unit 31 provided in the display device 20. May be set as appropriate. For example, the compression process may be performed using a conventionally known method such as run-length encoding. In run-length encoding, for example, when the first correction data generation data before compression is 0010000000011..., The encoded data is [0,2] [1,1] [0,8] [1 , 2]. Alternatively, the value of 0 can be omitted and expressed as [2] [1,1] [8] [1,2].

  By compressing the first correction data generation data in this way, depending on the compression processing method, for example, the first correction data generation data for a display device having a display panel of 360 pixels × 480 pixels is about 1 kbit, for example. Can be stored with a very small storage capacity. Therefore, an empty area of an existing memory provided in these display devices can be used as the first correction data generation data storage unit 31.

  The second moving average processing unit 14b applies to the luminance data extracted by the luminance data extraction unit 13 from the imaging data obtained by imaging the display screen of the display device 20 in a state where the imaging unit 12 displays the inspection image data. Then, a second moving averaging process is performed in which the luminance value of each pixel is replaced with the average value of the luminance values of each pixel included in a block having a predetermined size centered on each pixel. Hereinafter, the luminance value of each pixel after the second moving average process is referred to as a second moving average value.

  The predetermined size is sufficiently wider than the range of the spot-like luminance unevenness region, and the difference in the luminance value of the light emitted from the backlight at each position within the predetermined size is the appropriate luminance value of the luminance value in the luminance unevenness region. It is preferable to set a range that is sufficiently small with respect to deviation from the value. Specifically, in the case of a display panel of about several hundred pixels × several hundred pixels provided in a mobile device such as a mobile phone, it is preferably set in a range of 2 mm × 2 mm to 10 mm × 10 mm. In this embodiment, the display panel 21 of 360 pixels × 480 pixels is used, and the above range is 5 mm × 5 mm. Note that the length in the vertical direction and the length in the horizontal direction in the predetermined size are not necessarily the same.

  The second luminance unevenness detection unit 15b calculates the difference between the luminance value of each pixel extracted by the luminance data extraction unit 13 and the second moving average value for each pixel, and the absolute value of this difference is equal to or greater than a predetermined threshold value. A region where a predetermined number or more of pixels are continuous is detected as spot-like luminance unevenness. If the difference is less than a predetermined reference value, it is considered that there is no speckled luminance unevenness, and the second correction data generation data may not be generated. Further, the predetermined number may be set as appropriate according to the size, application, etc. of the display device 20 so that luminance unevenness can be prevented from being visually recognized.

  Further, as shown in FIG. 8, the second luminance unevenness detection unit 15b approximates each detected spot-like luminance unevenness region to a circular region. The approximation method to the circular region is not particularly limited, and various conventionally known methods can be used.

  Based on the detection result of the second luminance unevenness detection unit 15b, the second correction data generation data generation unit 16b generates second correction data generation data (correction data generation data) for making it difficult to view spotted luminance unevenness. Data), compression processing is performed on the generated second correction data generation data, and the compressed data is output to the drive control device 22a included in the display device 20.

  Specifically, the second correction data generation data generation unit 16b is configured to calculate the average luminance of each pixel in the region for the region that approximates the region extracted as the luminance unevenness by the second luminance unevenness detection unit 15b. Then, a difference from an appropriate luminance value (for example, the second moving average value of each pixel in the region) in which luminance unevenness does not occur in the region is calculated. That is, in the present embodiment, in order to reduce the capacity to be stored in the second correction data generation data storage unit 31b described later, the spot-like luminance unevenness area is approximated to a circle, and the approximate correction area has the same correction strength. We are going to make corrections. In the following description, when the difference is e (e> 0) (when bright brightness unevenness occurs), and when f (f <0) (when dark brightness unevenness occurs). Will be described.

  The second correction data generation data generation unit 16b causes the display data generation unit 11 to display an image corresponding to image data that is one gradation higher than the reference gradation value over the entire area of the display panel 21, and the imaging unit 12 Based on the luminance data extracted by the luminance data extraction unit 13 from the image data obtained by capturing the image, an appropriate luminance value for image data that is one gradation higher than the reference gradation value, and an appropriate luminance value for the image data of the reference gradation value, The difference A is calculated. The second correction data generation data generation unit 16b causes the display data generation unit 11 to display an image corresponding to image data that is one gradation lower than the reference gradation value over the entire area of the display panel 21, and the imaging unit 12 Based on the luminance data extracted by the luminance data extraction unit 13 from the image data obtained by capturing the image, the appropriate luminance value for the image data of the reference gradation value and the appropriate luminance value for the image data one gradation lower than the reference gradation value The difference B is calculated.

  Then, the ratio | e | / B of the absolute value | e | of the e to the B is calculated for each region where bright luminance unevenness occurs. When the ratio | e | / B is 1 or less, the number of adjustment correction pixels for correcting the gradation value of the image data to be lowered by one gradation in order to correct the luminance unevenness is set in each area. The ratio is set according to the ratio | e | / B of the included pixels. For example, in the region where the value of the ratio | e | / B is 1/3, the second correction data generation data is set so that one pixel is lowered by one gradation for every three pixels among the pixels included in the region. Is generated.

  Similarly, the ratio | f | / A between the absolute value | f | of the f and the A is calculated for each region where the dark luminance unevenness occurs. When the ratio | f | / A is 1 or less, the number of adjustment correction pixels for correcting the gradation value of the image data to be increased by one gradation in order to correct the luminance unevenness in each area. The ratio is set according to the ratio | f | / A of the included pixels. For example, in the region where the value of the ratio | f | / A is 1/3, the second correction data generation data is set so that one of three pixels among the pixels included in the region is raised by one gradation. Is generated.

  When the ratio (| e | / B, | f | / A, etc.) exceeds 1, each pixel in the region corresponding to the ratio is corrected by the gradation value corresponding to the integer part of the ratio, and the above Second correction data generation data for further correcting one gradation of the display image data for pixels (adjustment correction pixels) at a ratio corresponding to the fractional part of the ratio is generated. Alternatively, when the ratio (| e | / B, | f | / A, etc.) exceeds 1, the above ratio is divided by a number n of 2 or more that results in a division result of 1 or less when divided. You may make it produce the 2nd correction data production | generation data for making the display image data with respect to the pixel of the ratio according to this division result high n gradation.

  Further, the degree of luminance unevenness of each block (the degree of deviation of the luminance value with respect to the appropriate luminance value. Correction intensity) is set in advance in accordance with the magnitude of the ratio A / | e | or the ratio B / | f |. It is determined which of the plurality of groups (for example, eight groups of correction strengths 1 to 8 shown in FIG. 9A) belong to, and the determination result and each group are set in advance. The ratio of the adjustment correction pixel may be set based on the value. Alternatively, information indicating the group classification result may be included in the second correction data generation data instead of the ratio.

  In the above description, the second correction data generation data generation unit 16b corrects only the pixels in the detected luminance unevenness region. However, the present invention is not limited to this, and the luminance unevenness region and its peripheral region (for example, Pixels in a region including a luminance unevenness region and a range of several pixels or a few mm may be corrected. That is, the luminance unevenness region may be used as the correction region, and the region including the luminance unevenness region and its surrounding region may be used as the correction region. As described above, by including the peripheral region in the correction region, it is possible to make the luminance unevenness region less visible by blurring the outline of the luminance unevenness region.

  Further, it is not always necessary to correct all the detected luminance unevenness areas, and only a part of the detected brightness unevenness areas may be corrected. For example, it is possible to extract and correct only the luminance unevenness region that is easily visually recognized according to the size of the luminance unevenness region or the degree of deviation from the appropriate luminance value.

  The second correction data generation data generation unit 16b calculates the second correction data generation data for each of R (Red), G (Green), and B (Blue) subpixels.

  Note that second correction data generation data for one color (for example, G) of R, G, and B may be generated and shared for the other colors. Since spot-like luminance unevenness often occurs continuously within a predetermined range, the second correction data generation data generated for one color of R, G, and B is used for the other colors on both sides. Even when applied to sub-pixels, the degree of image quality is almost the same as when the second correction data generation data is generated for each of the R, G, and B colors. Further, by using the common second correction data generation data for each color of R, G, and B, compared to the case where individual second correction data generation data is generated for each color, the display device 20 described later is used. The storage capacity required for the second correction data generation data storage unit 31b for storing the second correction data generation data provided can be reduced.

  In the present embodiment, the second correction data generation data generation unit 16b approximates each luminance unevenness region where the spot-like luminance unevenness occurs to a circular region according to the size of the luminance unevenness region, The center coordinates (or pixels corresponding to the center coordinates) and the radius of the circular area, the ratio of the adjustment correction pixel for each circular area, and information indicating whether the adjustment correction pixel is increased or decreased by one gradation. The second correction data generation data is generated. If there is luminance unevenness with the ratio exceeding 1, the correction amount of the gradation value for each pixel included in the region corresponding to the luminance unevenness (correction for pixels other than the adjustment correction pixel) in addition to these pieces of information. Amount). Alternatively, when there is luminance unevenness with the ratio exceeding 1, the correction amount of the gradation value of the adjustment correction pixel (described above) is used instead of the information indicating whether the adjustment correction pixel is increased or decreased by one gradation. And the information indicating whether to increase or decrease the gradation value of the adjustment correction pixel.

  Thereafter, the second correction data generation data generation unit 16b performs a compression process on the generated second correction data generation data, and sends the second correction data generation data after the compression process to the drive control unit 22a of the display device 20. Output. Note that the compression processing method and the size of the second correction data generation data after compression are not particularly limited, and depend on the storage capacity of the second correction data generation data storage unit 31b provided in the display device 20. May be set as appropriate.

(1-2. Display device 20)
FIG. 1 is a block diagram illustrating a configuration of a drive control device 22 a provided in the display device 20. As shown in this figure, the drive control device 22a includes a first correction data generation data storage unit 31, a second correction data generation data storage unit 31b, a first decoding unit 32, and a first spatial dispersion processing unit 33. A correction data creation unit 41 including a first time dispersion processing unit 34, a second decoding unit 32b, a second spatial dispersion processing unit 33b, a second time dispersion processing unit 34b, and an integration processing unit 35, an adder / subtractor 36, A shift register 37, a first latch unit 38, a second latch unit 39, and a D / A conversion unit 40 are provided. The first decoding unit 32, the first spatial dispersion processing unit 33, and the first time dispersion processing unit 34 constitute a first correction data creation unit, and the second decoding unit 32b, the second spatial dispersion processing unit 33b, and A second correction data creation unit is configured by the second time dispersion processing unit 34b (none of which is shown).

  The first correction data generation data storage unit 31 stores the first correction data generation data (correction data generation data) input from the correction data generation data generation device 10 when the display device 20 is manufactured. It is memory. In the present embodiment, the first correction data generation data storage unit 31 stores the first correction data generation data that has been compressed by the correction data generation data creation device 10.

  When the display device 20 displays an image corresponding to the display image data on the display panel 21, the first decoding unit 32 stores the first correction data generation data stored in the first correction data generation data storage unit 31. , And the first correction data generation data is decoded and output to the first spatial distribution processing unit 33. If the storage capacity of the first correction data generation data storage unit 31 is sufficient, the first correction data generation unit 16 does not compress the first correction data generation data and generates the first correction data. For example, the first decoding unit 32 may be omitted.

  The first spatial dispersion processing unit 33 sets the position of the adjustment correction pixel in each source line corresponding to the luminance unevenness region based on the first correction data generation data input from the first decoding unit 32, and this setting First correction data indicating the result is output to the first time dispersion processing unit 34. Specifically, it is determined how many pixels from the end of the source line are to be adjusted and corrected (offset value), and the pixels and pixels at predetermined intervals from the pixels are set as adjusted correction pixels. .

  For the luminance unevenness area where the ratio is 1 or less, the gradation value of the adjustment correction pixel is changed by one gradation, while the other pixels are not corrected. For the luminance unevenness region where the ratio exceeds 1, the gradation value of each pixel in the luminance unevenness region is changed by the gradation value corresponding to the integer part of the ratio, and the gradation value of the adjustment correction pixel is changed. Further, one gradation is changed. Alternatively, in the luminance unevenness region where the ratio exceeds 1, the gradation value of the adjustment correction pixel may be changed by the gradation value corresponding to the value of n, but the other pixels may not be corrected.

  In addition, in the case where luminance unevenness occurs across a plurality of adjacent source lines, the positions of the adjustment correction pixels in the source lines in the extension direction of the source lines in each source line are different between adjacent source lines and distributed. Alternatively, the position of each adjustment correction pixel may be set. FIG. 10 is an explanatory diagram showing an example of the first correction data in this case.

  Based on the first correction data input from the first spatial dispersion processing unit 33, the first time dispersion processing unit 34 changes the position of the adjustment correction pixel in each source line every predetermined period (for example, every frame). The first correction data indicating the setting result is output to the integration processing unit 35. FIG. 11 is an explanatory diagram illustrating an example of the first correction data set by the first time dispersion processing unit 34. In the example shown in this figure, the first time distribution processing unit 34 sources the adjustment correction pixel position (offset value) for each frame while keeping the ratio of adjustment correction pixels (the pitch between the adjustment correction pixels) constant. The line is changed in the drawing direction.

  Note that the order of the first spatial dispersion processing unit 33 and the first time dispersion processing unit 34 may be reversed. That is, the first correction data generation data is input from the first decoding unit 32 to the first time distribution processing unit 34, and the first correction data is input from the first time distribution processing unit 34 to the first spatial distribution processing unit 33. It may be a configuration.

  The second correction data generation data storage unit 31b stores the second correction data generation data (correction data generation data) input from the correction data generation data generation device 10 when the display device 20 is manufactured. It is memory. In this embodiment, the second correction data generation data storage unit 31b stores the second correction data generation data subjected to the compression processing by the correction data generation data creation device 10.

  When the display device 20 displays an image corresponding to the display image data on the display panel 21, the second decoding unit 32b stores the second correction data generation data stored in the second correction data generation data storage unit 31b. , And the second correction data generation data is decoded and output to the second spatial dispersion processing unit 33b. If the storage capacity of the second correction data generation data storage unit 31b is sufficient, the second correction data generation data generation unit 16b generates the second correction data without compressing the second correction data generation data. The data may be stored in the data storage unit 31b, and in that case, the second decoding unit 32b may be omitted.

  The second spatial dispersion processing unit 33b sets the position of the adjustment correction pixel in each luminance unevenness region based on the second correction data generation data input from the second decoding unit 32b, and indicates the setting result. The correction data is output to the second time dispersion processing unit 34b.

  Specifically, the second spatial distribution processing unit 33b uses the second correction data generation data input from the second decoding unit 32b as a percentage of adjustment correction pixels (or a group classification result corresponding to the degree of luminance unevenness). The correction correction pixel is determined by extracting a correction position pattern corresponding to the detection result from a correction pattern storage unit (not shown). The correction pattern storage unit stores the adjustment correction pixels in the block according to the ratio of adjustment correction pixels included in the second correction data generation data (or a group classification result according to the degree of luminance unevenness). A pattern indicating the position is stored in advance. FIG. 9A shows an example of an arrangement pattern of adjustment correction pixels in the block in the case where the degree of luminance unevenness is classified into eight groups of correction intensities 1 to 8 (black circles in the figure are adjustment corrections). Pixel).

  12 (a) and 12 (b) show the second spatial distribution processing based on the second correction data generation data (information such as radius and adjustment correction pixel ratio) input from the second decoding unit 32b. It is explanatory drawing which shows an example of the arrangement pattern of the adjustment correction pixel which the part 33b determined. Specifically, FIG. 12A shows an example in which the radius of the circular area corresponding to the luminance unevenness area is classified into 6 (6 pixels) and the luminance unevenness area is classified into the correction intensity 3 group. FIG. 12B shows an example in which the radius of the circular area corresponding to the uneven brightness area is 9 (9 pixels), and the uneven brightness area is classified into the correction intensity 4 group.

  As shown in FIGS. 9A and 9B, the arrangement pattern of a plurality of adjustment correction pixels is arranged for each ratio of adjustment correction pixels (or each group according to the degree of luminance unevenness). The adjustment correction pixels may not be adjacent to each other by setting in advance and applying different arrangement patterns in adjacent blocks.

  In the above description, the correction pattern is stored in the correction pattern storage unit in advance. However, the present invention is not limited to this. For example, the ratio of adjustment correction pixels in the block (or group classification according to the degree of luminance unevenness) The position of the adjustment correction pixel may be calculated based on a predetermined arithmetic expression using the result as a parameter.

  In the above description, the position of the adjustment correction pixel is determined using a common arrangement pattern for each of the R, G, and B subpixels. However, the present invention is not limited to this, and an arrangement pattern is set for each color. You may do it. For example, as shown in FIG. 13, a correction pattern for the G subpixel and a correction pattern for the R and B subpixels for each group (or the ratio of the adjustment correction pixels) according to the degree of luminance unevenness. It may be set and each correction target sub-pixel may be selected using both of these correction patterns. Alternatively, both of these correction patterns may be used alternately.

  Based on the second correction data input from the second spatial dispersion processing unit 33b, the second time dispersion processing unit 34b determines the position of the adjustment correction pixel in each block for each predetermined period (in this embodiment, one frame). The second correction data indicating the setting result is output to the integration processing unit 35.

  For example, as shown in FIG. 9A and FIG. 9B, the ratio of the adjustment correction pixels included in the second correction data generation data (or each group according to the degree of luminance unevenness). On the other hand, an arrangement pattern of a plurality of adjustment correction pixels may be set in advance, and the arrangement pattern applied for each frame may be switched. Alternatively, as shown in FIG. 14, the position of the adjustment correction pixel may be changed for each frame by shifting the application position of the arrangement pattern for each frame.

  Note that the order of the second spatial dispersion processing unit 33b and the second time dispersion processing unit 34b may be reversed. That is, the second correction data generation data is input from the second decoding unit 32b to the second time dispersion processing unit 34b, and the second correction data is input from the second time distribution processing unit 34b to the second spatial dispersion processing unit 33b. It may be a configuration.

  The integrated processing unit 35 generates integrated correction data obtained by integrating the first correction data output from the first time dispersion processing unit 34 and the second correction data output from the second time dispersion processing unit 34b, and the adder / subtracter To 36.

  For example, the integration processing unit 35 uses the correction amount (tone correction value) of each pixel in the first correction data for correcting streaky luminance unevenness and the second correction data for correcting speckled luminance unevenness. Integrated correction data is generated by adding the correction amount (tone correction value) of each pixel for each corresponding pixel.

  Note that for a pixel in which the result of adding the correction amount in the first correction data and the correction amount in the second correction data exceeds a predetermined threshold value, the correction amount of the pixel may be set to the threshold value. For example, if the threshold value is set to ± 1, and the correction amount in the first correction data and the correction amount in the second correction data are both +1 gradation, the correction amount of the pixel is set to +1 gradation. That's fine. Similarly, for a pixel in which the correction amount in the first correction data and the correction amount in the second correction data are both −1 gradation, the correction amount of the pixel may be set to −1 gradation. The threshold value is not limited to ± 1, and can be set to any numerical value of 1 or more.

  The adder / subtracter 36 adds / subtracts the correction amount of each pixel in the integrated correction data to the pixel value of each pixel of the display image data corresponding to each pixel, and sequentially outputs it to the shift register 37. For example, the gradation value 1 is added when the correction amount is +1 gradation, and the gradation value 1 is subtracted when the correction amount is −1 gradation.

  In this embodiment, the pixel value of each pixel of the display image data is serially input to the adder / subtractor 36, and the integrated correction data is serially input from the integration processing unit 35 to the adder / subtractor 36 in synchronization therewith. It is like that.

  The shift register 37 is a serial input parallel output type (SIPO (Serial-In, Parallel-Out)) shift register, and the display image data for one gate line after addition / subtraction processing serially output from the adder / subtractor 36. Are converted into parallel and output to the first latch unit 38.

  The first latch unit 38 latches display image data for one line (one gate line) output in parallel from the shift register 37, and the second latch unit 39 is one line latched by the first latch unit 38. The image data for (1 gate line) is re-latched.

  The D / A conversion unit (digital / analog conversion unit) 40 converts the image data for one line (one gate line) latched by the second latch unit 39 into an analog signal and supplies it to each source line of the display panel 21. Output at a predetermined timing.

  The display panel 21 includes a large number of gate lines (scanning signal lines) and a large number of source lines (data signal lines). Pixels are respectively provided in each of the matrix regions defined by the gate lines and the source lines. Provided (none shown).

  Each pixel is composed of a switching transistor and a pixel capacitor, and the pixel capacitor is composed of a liquid crystal capacitor and an auxiliary capacitor that is added as necessary (none is shown). The switching transistor has a gate connected to the gate line, a source connected to the source line, and a drain connected to one electrode of the pixel capacitor. Note that the other electrode of the pixel capacitor is connected to a common electrode line common to all pixels.

  Thus, when a gate line is selected by a gate driver (not shown), the switching transistor of each pixel connected to the selected gate line is turned on, and in synchronization therewith, the D / D of the drive control device 22a. A voltage applied from the A converter 40 to each source line is applied to the corresponding pixel capacitor.

  Note that while the selection period of the gate line ends and the switching transistor is shut off, the pixel capacitor continues to hold the voltage at the time of the shut-off. Since the transmittance or reflectance of the liquid crystal changes depending on the voltage applied to the liquid crystal capacitor, the display state of the pixel is changed to image data by selecting a gate line and applying a voltage corresponding to the image data to the source line. It can be changed together.

  As described above, the display device 20 according to the present embodiment includes the adder / subtractor 36 that corrects the display image data by adding / subtracting the integrated correction data to / from the display image data. This eliminates the need for a multiplier and a bit compression circuit as compared with the configuration in which the display image data is multiplied by the correction data as in the prior art described above, thereby greatly reducing the circuit scale and manufacturing cost. Can be reduced.

  Further, in the present embodiment, a processing unit (a first correction data generation data storage unit 31, a first decoding unit 32, a first spatial dispersion processing unit) that generates first correction data for correcting streaky luminance unevenness. 33, and a first time dispersion processing unit 34) and processing units (second correction data generating data storage unit 31b, second decoding unit 32b) that generate second correction data for correcting spot-like luminance unevenness, A second spatial dispersion processing unit 33b and a second time dispersion processing unit 34b) are provided separately. Thereby, for example, the first correction data generation data compression method for correcting streaky luminance unevenness and the second correction data generation data compression method for correcting spot-like luminance unevenness are different. Even in this case, the correction processing based on both the correction data generation data can be performed efficiently.

  Further, in the present embodiment, when the display device 20 displays an image corresponding to the display image data on the display panel 21, the first correction data generation data stored in the first correction data generation data storage unit 31 is displayed. The adjustment correction pixel is selected based on the data and the second correction data generation data stored in the second correction data generation data storage unit 31b, and the correction amount of the gradation value of the selected adjustment correction pixel is adjusted to this adjustment correction. It is different from the correction amount of the gradation value for other pixels in the correction area to which the pixel belongs. Further, the number of pixels corresponding to the above ratio among the pixels included in the correction area is selected as the adjustment correction pixel based on the second correction data generation data stored in the second correction data generation data storage unit 31b. The gradation value correction amount of the selected adjustment correction pixel is made different from the gradation value correction amount for the other pixels.

  Thus, by making the correction amount of the adjustment correction pixel different from the correction amount of the other pixels among the pixels included in the correction region, the luminance values of all the pixels in the correction region are changed to one gradation of the display image data. It can be visually recognized in substantially the same manner as when the luminance value is uniformly corrected by less than the luminance value corresponding to the minute (or the luminance value corresponding to the gradation value in which the decimal part of the display image data is not 0). That is, the luminance value of all the pixels in the correction area is less than the luminance value corresponding to one gradation of the display image data (or the luminance value corresponding to the gradation value in which the decimal part of the display image data is not 0). Can be corrected in the middle tone. Therefore, it is possible to correct the luminance unevenness with high accuracy and more appropriately prevent the luminance unevenness from being visually recognized.

  FIG. 15 shows luminance data obtained from imaging data obtained by imaging the display panel 21 in a state in which an image corresponding to inspection image data that has not been subjected to the process of correcting streaky luminance unevenness, and streaky luminance. It is a graph which shows the brightness | luminance data of the brightness | luminance data obtained from the imaging data which imaged the display panel 21 on which the image according to the image data for test | inspection which performed the nonuniformity correction process was displayed. The horizontal axis indicates the position of each line pixel group, and the vertical axis indicates the luminance value of each line pixel group (the average value of the luminance values of the pixels belonging to each line pixel group). As is clear from these graphs, the correction method according to the present embodiment can correct the image data so that stripe-like luminance unevenness is not visually recognized.

  In the present embodiment, the position of the adjustment correction pixel in each correction area is changed every predetermined period (for example, every frame). That is, the positions of the adjustment correction pixels are dispersed spatially and temporally within the luminance unevenness region.

  As a result, the visible image is uniformly changed so that the luminance value of all pixels in the luminance unevenness region is less than the luminance value corresponding to one gradation of the display image data (or the gradation value whose decimal part is not 0). It is possible to get closer to the image in the case where Therefore, it is possible to more appropriately prevent the luminance unevenness from being visually recognized.

  In the present embodiment, the first correction data generation data storage unit 31 provided in the display device 20 stores information indicating the position of the luminance unevenness region and the ratio of the adjustment correction pixels to the luminance unevenness region (adjustment correction pixel interval). ) And information indicating whether to raise or lower at least one gradation for the adjustment correction pixel, and the first spatial dispersion processing unit 33 and the first time dispersion processing unit 34 provided in the display device 20 When displaying an image according to the display image data, the positions of the adjustment correction pixels in the luminance unevenness region are determined to be dispersed spatially and temporally. As a result, the data size of the first correction data generation data can be reduced, and the storage capacity required for the first correction data generation data storage unit 31 can be reduced.

  However, the present invention is not limited to this, and the position of the adjustment correction pixel when displaying the display image data is set in advance in the correction data generation data creation device 10, and the position of each adjustment correction pixel and the first floor of each adjustment correction pixel are set. You may make it memorize | store in the data memory | storage part 31 for 1st correction data generation | occurrence | production which shows whether to raise or lower. That is, the first spatial dispersion processing unit 33 and the first time dispersion processing unit 34 may be provided in the correction data generation data creation device 10 instead of the display device 20. In this case, the circuit configuration of the display device 20 can be simplified, and the processing speed for the display image data correction process can be increased.

  In the present embodiment, when calculating the deviation of the luminance value with respect to the appropriate luminance value in each luminance unevenness region, the moving value of the luminance value of the line pixel group is regarded as the appropriate luminance value, and the deviation of the above luminance value is calculated. To do. As a result, even if the appropriate luminance value varies depending on the position on the display screen due to, for example, the luminance distribution of the irradiation light from the backlight, the degree of deviation of the luminance value with respect to the appropriate luminance value in each luminance unevenness region is reduced. It can be calculated easily and appropriately. For example, when an appropriate luminance value corresponding to a position on the display screen is known in advance, a deviation of the luminance value in each luminance unevenness region may be calculated based on the appropriate luminance value.

  In the present embodiment, the correction region corresponding to the spot-like luminance unevenness is approximated to a circular region, and the second coordinate data generation data is obtained by using the center coordinates and radius of the circular region as information indicating the position of the correction region. Include in Thus, the second correction data generation data includes the center coordinates and radius of each correction area, the ratio of the number of adjustment correction pixels in each correction area (or information indicating a group classified according to the degree of luminance unevenness), Since it is only necessary to include four parameters of information indicating whether the gradation value of the adjustment correction pixel is increased or decreased by one gradation, the data amount of the second correction data generation data is reduced and the display device 20 is reduced. It is possible to reduce the storage capacity required for the second correction data generation data storage unit 31b provided.

  Note that the correction region is not limited to a configuration that approximates a circular region, and may be approximated to, for example, a polygon. In that case, as the information indicating the position and range of the correction area, for example, the position of each vertex of the polygon may be included in the correction data generation data. When the polygon is a regular polygon, The center position and radius of the circumscribed circle or inscribed circle of the polygon may be included in the correction data generation data.

  In addition, data for spatially and temporally dispersing the positions of the adjustment correction pixels is generated in advance in the correction data generation data generation device 10 and this data is stored in the second correction data generation data storage unit 31b. It may be. That is, the second spatial dispersion processing unit 33b and the second time dispersion processing unit 34b may be provided in the correction data generation data creation device 10 instead of the display device 20. In this case, the circuit configuration of the display device 20 and the image data correction process can be simplified and the processing speed can be increased.

[Embodiment 2]
Another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 16 is a block diagram illustrating a configuration of a drive control device 22b provided in the display device 20 according to the present embodiment. The drive control device 22b is provided in the display device 20 instead of the drive control device 22a in the first embodiment. As shown in this figure, the drive control device 22b includes a frame comparison unit 42, a RAM (frame buffer) 43, and a shift register 44 in addition to the configuration of the drive control device 22a in the first embodiment.

  The RAM 43 is a memory (so-called frame buffer memory) that stores display image data for one frame (one screen), and stores it at a predetermined timing according to a clock signal input from a control unit (not shown). The display image data for one frame is output to the shift register 44 in parallel by one line (one gate line). In the present specification, the case where the RAM 43 outputs image data in parallel for each pixel corresponding to one gate line will be mainly described. However, the present invention is not limited to this, and each pixel corresponding to one gate line on the display screen is displayed. It may be divided into groups of a plurality of pixels, and image data may be output in parallel for each of the divided groups.

  The frame comparison unit 42 stores display image data of one frame (a frame (second frame) to be displayed next to the display image data stored in the RAM 43) input from the outside, and is stored in the RAM 43. The display image data for one frame before the corresponding frame is compared. When the two display image data are different, the frame comparison unit 42 updates the display image data stored in the RAM 43 to the display image data for one frame input from the outside. On the other hand, when both the display image data are the same, the frame comparison unit 42 does not update the display image data stored in the RAM 43, and continues to store the display image data already stored in the RAM 43. As a result, when the display image data of the next frame to be displayed is the same as the display image data of the previously displayed frame, the display is performed based on the common display image data stored in the RAM 43. .

  The shift register 44 is a serial input parallel output type (PISO (Parallel-In, Serial-Out)) shift register, and serially displays image data for one line (one gate line) output from the RAM 43 in parallel. And output to the adder / subtracter 36 pixel by pixel.

  The adder / subtractor 36 receives a high-speed clock (clock having a frequency equal to or higher than the horizontal scanning frequency multiplied by the number of source lines) from a control circuit (not shown), and outputs from the shift register 44 in synchronization with the high-speed clock. Then, the integration correction data for each pixel input from the correction data creation unit 41 is added to or subtracted from the display image data for each pixel.

  The configurations of the correction data creation unit 41, the shift register 37, the first latch unit 38, the second latch unit 39, and the D / A conversion unit 40 are the same as those in the first embodiment.

  As described above, in this embodiment, the display image data for one frame is output in parallel for each line (one gate line), and the display image data output in parallel from the RAM 43 is converted into serial data. And a shift register 44 for outputting to the adder / subtractor 36 one pixel at a time.

  Thereby, even in the configuration including the RAM 43 that outputs the display image data in parallel, the display image data that is serially output from the shift register 44 by one pixel and the correction data creation unit 41 by one pixel at a time. Addition / subtraction processing with the integrated correction data output serially can be performed, and luminance unevenness correction processing for the display image data can be performed. Further, since only the adder / subtractor 36 for adding / subtracting the display image data for one pixel and the integrated correction data for one pixel is required, the display image data is multiplied by the correction data as in the above-described prior art. Since it is not necessary to provide a multiplier or a bit compression circuit as compared with the configuration, the circuit scale can be greatly reduced, and the manufacturing cost can be greatly reduced.

[Embodiment 3]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 17 is a block diagram illustrating a configuration of the drive control device 22c provided in the display device 20 according to the present embodiment. The drive control device 22c is provided in the display device 20 instead of the drive control device 22a in the first embodiment. As shown in this figure, the drive control device 22c is provided with an adder / subtractor 36b in place of the adder / subtractor 36, and a serial input parallel output type shift register 37 is provided between the correction data generator 41 and the adder / subtractor 36b. Unlike the drive control device 22b in the second embodiment, the parallel input serial output type shift register 44 is not provided, and the output from the RAM 43 is directly input to the adder / subtractor 36b. ing.

  The shift register 37 converts the integrated correction data serially output for each pixel from the correction data creation unit 41 into parallel, and outputs the converted correction data to the adder / subtractor 36b by one line (one gate line).

  An adder / subtracter (parallel adder / subtractor) 36b is provided for each pixel data in the display image data output in parallel by one line (one gate line) from the RAM 43 and one line (one gate line) from the shift register 37. Data of each pixel in the display image data output in parallel is subjected to addition / subtraction processing, and is output to the first latch unit 38 in parallel for one line (one gate line). Specifically, the adder / subtractor 36b includes the same number of adders / subtractors as the number of source lines for adding / subtracting display image data for one pixel and integrated correction data for one pixel, and one line (one gate line). ) Is added and subtracted in parallel.

  As described above, in this embodiment, the display image data for one frame is output serially for each pixel from the RAM 43 that outputs the image data for one line (one gate line) in parallel and the correction data creation unit 41. There is provided a shift register 37 for converting the integrated correction data into parallel and outputting it to the adder / subtractor 36b by one line (one gate line). The adder / subtractor 36b performs addition / subtraction processing for each pixel for one line (one gate line) in parallel.

  Thereby, even if it is the structure provided with RAM43 which outputs the image data for a display in parallel, the correction process of the brightness nonuniformity with respect to the image data for a display can be performed. Further, since only the adder / subtractor 36b for adding / subtracting the display image data for one line and the integrated correction data for one line need be provided, the display image data is multiplied by the correction data as in the above-described prior art. Since it is not necessary to provide a multiplier or a bit compression circuit as compared with the configuration, the circuit scale can be greatly reduced, and the manufacturing cost can be greatly reduced.

[Embodiment 4]
Still another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 18 is a block diagram illustrating a configuration of a drive control device 22d provided in the display device 20 according to the present embodiment. The drive control device 22d is provided in the display device 20 instead of the drive control device 22a in the first embodiment. As shown in this figure, the drive control device 22d includes a correction data creation unit 41, an adder / subtractor 36, a first latch unit 38, a second latch unit 39, a D / A conversion unit 40, a frame comparison unit 42, a RAM 43, and an inverse. A conversion data generation unit 45 and a second adder / subtractor 46 are provided.

  The adder / subtracter 36 performs an addition / subtraction process between the display image data serially input pixel by pixel from the frame comparison unit 42 and the integrated correction data serially input pixel by pixel from the correction data creation unit 41. The subsequent display image data is stored in the RAM 43. Further, the adder / subtractor 36 outputs the result of the addition / subtraction process for each pixel to the inverse transformation data generation unit 45.

  The RAM 43 stores display image data for one line (one gate line), and outputs the stored display image data to the first latch unit 38 in parallel by one line (one gate line) at a predetermined timing. .

  Based on the result of the addition / subtraction process input from the adder / subtractor 36, the inverse transform data generation unit 45 returns the display image data after the addition / subtraction process stored in the RAM 43 to the display image data before the addition / subtraction process. Inverse conversion data is generated and output to the second adder / subtractor 46. For example, reverse conversion data for lowering one gradation is generated for a pixel that has been increased by one gradation by addition / subtraction processing, and reverse conversion data for increasing one gradation for a pixel that has been decreased by one gradation by addition / subtraction processing. Is generated.

  The second adder / subtractor 46 performs display image data stored in the RAM 43 by performing addition / subtraction processing on the reverse conversion data input from the reverse conversion data generation unit 45 with respect to the display image data stored in the RAM 43. Inverse processing of addition / subtraction processing by the adder / subtractor 36 is performed on the data, the data is restored to the state before the addition / subtraction processing is performed, and is output to the frame comparison unit 42.

  The frame comparison unit 42 compares the display image data input from the second adder / subtractor 46 with the display image data of the next frame input from the outside. If the two display image data are different, the display image data of the next frame is output to the adder / subtractor 36 to perform the addition / subtraction processing of the integrated correction data. On the other hand, when both display image data are the same, the frame comparison unit 42 does not perform addition / subtraction processing by the adder / subtractor 36, and the display image data of the previous frame stored in the RAM 43 is latched from the RAM 43 to the first latch. The data is output to the unit 38 and displayed.

  As described above, in the present embodiment, the RAM 43 that stores display image data for one frame subjected to addition / subtraction processing for luminance unevenness correction, and the display image data stored in the RAM 43 are described above. Inverse conversion data generation unit 45 and second adder / subtractor 46 for performing an inverse conversion process for returning to display image data before the addition / subtraction process is performed, and display image data for one frame subjected to the inverse conversion process And a frame comparison unit that compares display image data of the next frame input from the outside.

  Thereby, even if it is the structure provided with RAM43 which outputs the image data for a display in parallel, the correction process of the brightness nonuniformity with respect to the image data for a display can be performed. Further, since it is only necessary to include an adder / subtractor 36b for adding / subtracting the display image data for one pixel and the integrated correction data for one pixel, the display image data is multiplied by the correction data as in the conventional technique described above. Since it is not necessary to provide a multiplier or a bit compression circuit as compared with the configuration, the circuit scale can be greatly reduced, and the manufacturing cost can be greatly reduced.

  Further, display image data for one frame before luminance unevenness correction obtained by inversely transforming the display image data for one frame after luminance unevenness correction stored in the RAM 43, and the next before luminance unevenness correction. When the display image data of the frame is compared and the display image data is the same, the luminance unevenness correction processing (addition / subtraction processing) by the adder / subtractor 36 is omitted and the display image data stored in the RAM 43 is stored. The display can be performed based on the display image data after the luminance unevenness correction already stored in the RAM 43 without updating. Thereby, processing efficiency can be improved and reduction of power consumption can be aimed at.

  Note that luminance unevenness is generally easily recognized when a halftone image (particularly a dark gray image) is displayed, and a white image (or an image close to white) or a black image (or an image close to black) is displayed. When it is used, it is relatively difficult to see. For this reason, when the above-described luminance unevenness correction process is performed when displaying a white image or a black image, the corrected region may be visually recognized.

  For this reason, in each of the above-described embodiments, the upper limit value and the lower limit value of the display image data to be corrected for luminance unevenness are set in advance, and the gradation level of the display image data before the correction process is set to the upper limit. If the value is greater than or equal to the value and less than or equal to the lower limit value, the correction process may not be performed. For example, the integrated correction data is input from the correction data creation unit 41 to the frame comparison unit 42, and the average value of the gradation values of the pixels belonging to the correction region in the display image data input from the outside by the frame comparison unit 42 and the above upper limit The value and the lower limit value may be compared, and the adder / subtractor 36 may be controlled so that the correction process (addition / subtraction process) is not performed on the correction area above the upper limit value and the correction area below the lower limit value.

  Generally, when a dark gray image is displayed, luminance unevenness is easily visible. For example, the lower limit value is 10% of the maximum gradation value (white image), and the upper limit value is the gradation value. What is necessary is just to set to 80% of the maximum value. Specifically, for example, with respect to the gradation values 0 to 63 that the display image data can take (0 is a black image and 63 is a white image), the lower limit value is a gradation value 6 and the upper limit value is a gradation value 51. And correction processing for luminance unevenness is not performed for the correction region in which the average value of the gradation values of each pixel in the display image data before the correction processing is 6 or less and the correction region that is 51 or more. Good.

  Note that the upper limit value and the lower limit value described above are, for example, a visual test for luminance unevenness when an image corresponding to image data of each gradation level is displayed on the display panel 21, or correction processing for image data of each gradation level. What is necessary is just to set suitably according to the result of the visual test whether a correction | amendment area | region is visually recognized unnaturally when performing and displaying.

  Further, the present invention is not limited to the configuration in which the average value of the gradation value of each pixel belonging to the correction area is compared with the upper limit value and the lower limit value. For example, the maximum value, the minimum value, and the maximum gradation value of each pixel belonging to the correction area An intermediate value between the minimum value and the minimum value, an average value of gradation values for some of the pixels belonging to the correction area, a maximum value, a minimum value, an intermediate value between the maximum value and the minimum value, and an upper limit You may make it compare a value and a lower limit.

  Further, the gradation value of each pixel included in the correction area in the display image data is compared with a predetermined upper limit value and lower limit value, and a pixel whose gradation value is equal to or higher than the upper limit value and lower than the lower limit value. It is also possible to adopt a configuration in which the gradation value is not corrected for the pixels.

  In each of the above embodiments, the configuration in which the correction data for correcting both the stripe-shaped luminance unevenness and the spot-shaped luminance unevenness is added to or subtracted from the display image data is described, but the present invention is not limited to this. For example, correction data for correcting only one of streaky luminance unevenness or speckled luminance unevenness may be added to or subtracted from display image data. Further, the present invention is not limited to the configuration in which the luminance unevenness correction data is added to or subtracted from the display image data. For example, when the display device is a liquid crystal display device, unevenness in the display image due to the variation in the luminance of light emitted from the backlight is corrected. The correction data for correction may be added to or subtracted from the display image data. Further, in a display device in which a display screen is formed by combining a plurality of display panels, correction data for correcting display image unevenness due to variations in characteristics of each display panel in the vicinity of the association portion of each display panel is provided. The display image data may be added or subtracted.

  Further, in each of the above embodiments, the correction data generation data creation device 10 is provided separately from the display device 20, but the present invention is not limited to this, and a part of the correction data generation data creation device 10 is provided. Or it is good also as a structure with which all are provided in the display apparatus 20. FIG. Of the correction data generation data creation device 10, each unit except the imaging unit 12 is provided in the display device 20, and imaging data acquired by imaging the display screen of the display panel 21 by the imaging unit 12 is provided in the display device 20. Alternatively, the data may be input to the correction data generation data creation device 10.

  In each of the above embodiments, each unit (each block) included in the correction data generation data creation device 10 or the drive control devices 22a to 22d may be realized by software using a processor such as a CPU. In this case, each block includes a CPU (central processing unit) that executes instructions of a control program that realizes each function, a ROM (read only memory) that stores the program, and a RAM (random access memory) that expands the program. And a storage device (recording medium) such as a memory for storing the program and various data. An object of the present invention is to provide a recording medium in which a program code (execution format program, intermediate code program, source program) of the control program for each block, which is software that realizes the functions described above, is recorded so as to be readable by a computer. This is achieved by supplying the correction data generation data creation device 10 or the drive control devices 22a to 22d and reading and executing the program code recorded on the recording medium by the computer (or CPU or MPU).

  Examples of the recording medium include a tape system such as a magnetic tape and a cassette tape, a magnetic disk such as a floppy (registered trademark) disk / hard disk, and an optical disk such as a CD-ROM / MO / MD / DVD / CD-R. Card system such as IC card, IC card (including memory card) / optical card, or semiconductor memory system such as mask ROM / EPROM / EEPROM / flash ROM.

  The correction data generation data creation device 10 or the drive control devices 22a to 22d may be configured to be connectable to a communication network, and the program code may be supplied via the communication network. The communication network is not particularly limited. For example, the Internet, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication. A net or the like is available. Also, the transmission medium constituting the communication network is not particularly limited. For example, even in the case of wired such as IEEE 1394, USB, power line carrier, cable TV line, telephone line, ADSL line, etc., infrared rays such as IrDA and remote control, Bluetooth ( (Registered trademark), 802.11 wireless, HDR, mobile phone network, satellite line, terrestrial digital network, and the like can also be used. The present invention can also be realized in the form of a computer data signal embedded in a carrier wave in which the program code is embodied by electronic transmission.

  The blocks of the correction data generation data creation device 10 or the drive control devices 22a to 22d are not limited to those realized using software, but may be configured by hardware logic. A combination of hardware that performs a part and arithmetic means that executes software for controlling the hardware and performing the remaining processing may be used.

  In each of the above embodiments, the case where the present invention is applied to a liquid crystal display device has been described. However, the application target of the present invention is not limited to this, and for example, a display device such as a plasma display or an organic EL display. Applicable.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The present invention can be applied to various display devices such as a liquid crystal display device, a plasma display, and an organic EL display, and these display devices.

DESCRIPTION OF SYMBOLS 10 Correction data generation data preparation apparatus 20 Display apparatus 21 Display panels 22a-22d Drive control apparatus 31 1st correction data generation data storage part 31b 2nd correction data generation data storage part 32 1st decoding part (1st correction data) Production Department)
32b 2nd decoding part (2nd correction data creation part)
33 1st spatial dispersion | distribution process part (1st correction data creation part)
33b Second spatial dispersion processing unit (second correction data creation unit)
34 1st time dispersion | distribution process part (1st correction data creation part)
34b Second time dispersion processing unit (second correction data creation unit)
35 Integrated Processing Unit 36 Adder / Subtracter (Addition / Subtraction Unit)
36b Adder / Subtracter (Parallel Adder / Subtractor, Adder / Subtractor)
37 Shift register (serial input parallel output type shift register)
38 First latch section 39 Second latch section 40 D / A conversion section 41 Correction data creation section 42 Frame comparison section 43 RAM (frame buffer)
44 Shift register (parallel input serial output type shift register)
45 Inverse transformation data generation unit (inverse transformation processing unit)
46 Second adder / subtracter (inverse conversion processing unit)

Claims (11)

A display screen for displaying an image corresponding to the display image data, and a correction process for correcting luminance unevenness of the display screen are performed on the display image data, and the display image data after the correction process is displayed. A drive control unit for controlling the display state of each pixel of the display screen based on the display device,
The drive control unit
The gradation correction value of each pixel in the correction data indicating the gradation correction value for correcting the luminance unevenness for each pixel is added to or subtracted from the luminance value of the pixel of the display image data corresponding to the pixel. a subtraction unit for performing the correction process by,
When an image corresponding to the inspection image data is displayed on the display screen, at least one of the luminance unevenness areas, which is an area where an image having a luminance value different from the appropriate luminance value corresponding to the inspection image data is displayed. In the display unevenness region, the difference between the brightness value when the image corresponding to the display image data is displayed and the appropriate brightness value corresponding to the display image data is reduced in the display image data. Correction data used to generate correction data for correcting the gradation values of pixels included in a correction region that is a region corresponding to at least a part of the luminance unevenness region or a region including the luminance unevenness region and its peripheral region A data storage unit for generating correction data for storing data for generation;
When displaying an image corresponding to the display image data on the display screen, the gradation value of at least some of the pixels included in the correction area is changed based on the correction data generation data. A correction data creating unit for generating the correction data for correcting the display image data as described above,
The display screen is arranged such that a large number of scanning signal lines arranged in parallel to each other and a large number of data signal lines arranged in parallel to each other intersect, and an intersection of the scanning signal lines and the data signal lines A pixel is provided for each
The correction data generation data storage unit includes:
In the display screen, first correction data generation data used to generate first correction data for correcting streaky luminance unevenness existing so as to extend in a direction parallel to the extension direction of the data signal line is stored. 1 correction data generation data storage unit;
A second correction data generation data storage unit that stores second correction data generation data used to generate second correction data for correcting spot-like luminance unevenness locally present on the display screen;
The correction data creation unit
When displaying an image corresponding to the display image data on the display screen, based on the first correction data generation data, at least one of the pixels included in the correction region corresponding to the streaky luminance unevenness A first correction data generating unit that generates the first correction data for correcting the display image data so as to change the gradation values of some pixels;
When displaying an image corresponding to the display image data on the display screen, based on the second correction data generation data, at least of the pixels included in the correction region corresponding to the spot-like luminance unevenness A second correction data generating unit for generating the second correction data for correcting the display image data so as to change the gradation values of some pixels;
An integrated processing unit that generates integrated correction data obtained by integrating the first correction data and the second correction data,
The addition / subtraction unit performs the correction process by adding or subtracting the gradation correction value of each pixel in the integrated correction data to the luminance value of the pixel of the display image data corresponding to the pixel. Display device.   The addition / subtraction unit is configured such that the display image data and the correction data are input in series for each pixel, and the luminance value of each pixel of the display image data input in series is determined. 2. The display device according to claim 1, wherein gradation correction values of pixels of the correction data corresponding to the pixels are sequentially added or subtracted pixel by pixel. The display screen is arranged such that a large number of scanning signal lines arranged in parallel to each other and a large number of data signal lines arranged in parallel to each other intersect, and an intersection of the scanning signal lines and the data signal lines A pixel is provided for each
The display image data for one frame is stored, and the stored display image data is grouped for each pixel corresponding to one scanning signal line of the display screen or each pixel corresponding to one scanning signal line is composed of a plurality of pixels. RAM that outputs in parallel for each group divided into
A parallel input serial output type shift register that outputs the display image data for each pixel corresponding to one scanning signal line of the display screen output from the RAM in series for each pixel;
The adding / subtracting unit calculates a gradation correction value of a pixel of the correction data corresponding to each pixel with respect to a luminance value of each pixel of the display image data output in series for each pixel from the shift register. The display device according to claim 2, wherein addition or subtraction is sequentially performed for each pixel. The memory stores the display image data of one frame in which the correction processing has been performed by the upper Symbol subtraction unit, each pixel display image data stored corresponding to one scanning signal line of the display screen or one scanning signal line A RAM that outputs each pixel corresponding to each group divided into a group of a plurality of pixels in parallel;
And the correction processing is performed by the subtraction unit performs inverse transformation processing of the correction processing on the display image data stored in the RAM, restores the display image data before the correction process is performed An inverse transformation processing unit,
A frame comparison unit that compares the display image data restored by the inverse conversion process with the display image data of the second frame that is a frame to be displayed next to the display image data stored in the RAM. And
When the frame comparison unit determines that the display image data restored by the inverse transformation process is different from the display image data of the second frame, the addition / subtraction unit is configured to display the second frame display image. Display for one frame to be stored in the RAM by performing the correction process by adding or subtracting the gradation correction value of the pixel of the correction data corresponding to each pixel to the luminance value of each pixel of the data The image data is updated to the display image data after the correction process, and the frame comparison is performed if the display image data restored by the inverse conversion process and the display image data of the second frame are the same. 3. The display device according to claim 2, wherein the display image data stored in the RAM is not updated when the determination unit determines. The display image data for one frame is stored, and the stored display image data is grouped for each pixel corresponding to one scanning signal line of the display screen or each pixel corresponding to one scanning signal line is composed of a plurality of pixels. RAM that outputs in parallel for each group divided into
A serial input parallel output type shift register that outputs the correction data input in series for each pixel in parallel for each pixel corresponding to each pixel corresponding to one scanning signal line of the display screen;
The addition / subtraction unit outputs one scan signal of the display screen from the shift register to each pixel of the display image data input in parallel for each pixel corresponding to one scan signal line of the display screen from the RAM. The display device according to claim 1, wherein gradation correction values of pixels corresponding to the pixels in correction data input in parallel for each pixel corresponding to a line are added or subtracted in parallel. The drive control unit includes an average value, a maximum value, a minimum value, an intermediate value between the maximum value and the minimum value of pixels included in the correction area in the display image data, or included in the correction area. Any one of average value, maximum value, minimum value, intermediate value between maximum value and minimum value, and predetermined upper limit value and lower limit value of gradation values of some of the pixels When any one of the values is equal to or greater than the upper limit and when any one of the values is equal to or less than the lower limit, the pixels belonging to the correction region in the display image data The display device according to claim 1 , wherein the gradation value is not corrected. The drive control unit compares a gradation value of each pixel included in the correction area in the display image data with a predetermined upper limit value and lower limit value, and the gradation value is equal to or greater than the upper limit value. The display device according to claim 1 , wherein gradation values are not corrected for the pixels and pixels that are equal to or lower than the lower limit value. The correction data creation unit
A part of the pixels included in the correction area is selected as the adjustment correction pixel, and the correction amount of the gradation value for the adjustment correction pixel is set to the gradation value for pixels other than the adjustment correction pixel included in the correction area. The display device according to claim 1 , wherein the display device is different from the correction amount. The correction data creation unit
9. The display device according to claim 8 , wherein each of the adjustment correction pixels is selected so that the adjustment correction pixels are dispersed in the correction area without being crowded. The correction data creation unit
The display device according to claim 8 or 9 , wherein a pixel selected as the adjustment correction pixel is changed at predetermined intervals within the correction region. A display screen for displaying an image corresponding to the display image data, and a correction process for correcting luminance unevenness of the display screen are performed on the display image data, and the display image data after the correction process is displayed. A method for correcting luminance unevenness of the display screen in a display device comprising: a drive control unit that controls a display state of each pixel of the display screen based on:
The display screen is arranged such that a large number of scanning signal lines arranged in parallel to each other and a large number of data signal lines arranged in parallel to each other intersect, and an intersection of the scanning signal lines and the data signal lines A pixel is provided for each
When an image corresponding to the inspection image data is displayed on the display screen, at least one of the luminance unevenness areas, which is an area where an image having a luminance value different from the appropriate luminance value corresponding to the inspection image data is displayed. In the display unevenness region, the difference between the brightness value when the image corresponding to the display image data is displayed and the appropriate brightness value corresponding to the display image data is reduced in the display image data. Correction data used to generate correction data for correcting the gradation values of pixels included in a correction region that is a region corresponding to at least a part of the luminance unevenness region or a region including the luminance unevenness region and its peripheral region A correction data generation data storage step for storing the generation data in a correction data generation data storage unit provided in the display device;
When the drive control unit displays an image corresponding to the display image data on the display screen, at least some of the pixels included in the correction region based on the correction data generation data are displayed. A correction data generating step for generating the correction data for correcting the display image data so as to change the gradation value;
The drive control unit determines the gradation correction value of each pixel in the correction data indicating the gradation correction value for correcting the luminance unevenness for each pixel of the pixel of the display image data corresponding to the pixel. look including a subtraction step of performing the correction processing by adding or subtracting the luminance value,
The correction data generation data storage step includes
In the display screen, the first correction data generation data used to generate the first correction data for correcting streaky luminance unevenness extending so as to extend in a direction parallel to the extending direction of the data signal line is the correction data. A first correction data generation data storage step to be stored in the generation data storage unit;
Second correction data for storing second correction data generation data used to generate second correction data for correcting spot-like luminance unevenness locally present on the display screen in the correction data generation data storage unit. A data storage process for generation,
The correction data creation process is as follows:
When displaying an image corresponding to the display image data on the display screen, based on the first correction data generation data, at least one of the pixels included in the correction region corresponding to the streaky luminance unevenness A first correction data creating step for generating the first correction data for correcting the display image data so as to change the gradation values of some pixels;
When displaying an image corresponding to the display image data on the display screen, based on the second correction data generation data, at least of the pixels included in the correction region corresponding to the spot-like luminance unevenness A second correction data creating step for generating the second correction data for correcting the display image data so as to change the gradation values of some pixels;
An integrated processing step of generating integrated correction data obtained by integrating the first correction data and the second correction data,
In the addition / subtraction step, the correction processing is performed by adding or subtracting the gradation correction value of each pixel in the integrated correction data to the luminance value of the pixel of the display image data corresponding to the pixel. A luminance unevenness correction method for a display device.

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