Display device and display method

Abstract

A display device (10) comprises: a display unit (13) that displays a video based on a video signal; and a control unit (14) that controls the display unit. The control unit executes detection processing (S1) for detecting, from the video represented by the video signal, a region (A) which includes high-gradation pixels that are pixels in a predetermined high-gradation range and low-gradation pixels that are pixels in a predetermined low-gradation range, and includes a pattern having a combination of the high-gradation pixel and the low-gradation pixel adjacent to each other, and averaging processing (S2) for averaging the gradations of pixels in the region.

Description

Display device and display method

[0001] The present invention relates to a display device and a display method.

[0002] In a display device, a technique for detecting a specific input pattern and changing pixel control is known (see, for example, Patent Document 1). When displaying a white dot (pixel) in the center of a black background (display of a killer pattern), the pixels in the row above the white pixel may have a whiter color than the original black (occurrence of black floating), and the quality of the image may deteriorate (see paragraph 0021 of Patent Document 1). In Patent Document 1, such a killer pattern is detected, and by controlling the drive transistor that drives the pixel, the occurrence of black floating and the like is suppressed. That is, when displaying an image including a killer pattern, the control unit of this display device sets the counter voltage of the pixel so that the potential difference from the gradation voltage written to the pixel becomes small (see paragraph 0065).

[0003] Japanese Patent Application Laid-Open No. 2021-173871

[0004] However, in the conventional technology as described above, individual drive control for each pixel (for example, control of the drive transistor that drives the pixel) is required. For this reason, there is a possibility of causing complexity in the display device, such as adding a control mechanism for individual drive control for each pixel.

[0005] An object of the present invention is to realize a display device and a display method that reduce the necessity of individual drive control for each pixel in order to prevent deterioration of display quality.

[0006] The display device according to the present invention includes a display unit that displays an image based on a video signal, and a control unit that controls the display unit. The control unit includes high-gradation pixels that are pixels in a predetermined high-gradation range and low-gradation pixels that are pixels in a predetermined low-gradation range from the image represented by the video signal, and detects a region including a pattern having a combination of adjacent high-gradation pixels and low-gradation pixels, and executes an averaging process for averaging the gradations of the pixels in the region.

[0007] According to the present invention, it is possible to realize a display device and a display method that reduce the need for individual drive control for each pixel in order to prevent a decrease in display quality.

[0008] This is a block diagram showing an example of a display device according to an embodiment of the present invention. This is a flowchart showing an example of a display method according to an embodiment of the present invention. This is a plan view showing an example of a pattern flowchart showing an example of a detection process according to an embodiment of the present invention. This is a plan view showing an example of a pattern according to an embodiment of the present invention. This is a flowchart showing another example of a detection process according to an embodiment of the present invention. This is a plan view showing an example of an averaging process according to an embodiment of the present invention. This is a plan view showing an example of a gamma curve. This is a schematic diagram showing an example of an averaging process according to an embodiment of the present invention.

[0009] Hereinafter, one embodiment of the present invention will be described in detail. Figure 1 is a block diagram showing an example of a display device 10 according to an embodiment of the present invention. As shown in Figure 1, the display device 10 includes a video signal processing unit 11, a driver 12, a display unit 13, a control unit 14, and a storage unit 15.

[0010] The display device 10 is either a self-emissive display device or a liquid crystal display device. If the display device 10 is a self-emissive display device, the display unit 13 is composed of a self-emissive display unit, for example, an EL (electroluminescent) display element. If the display device 10 is a liquid crystal display device, the display unit 13 is composed of liquid crystal display elements.

[0011] The video signal processing unit 11 processes the video signal IS and outputs it to the driver 12. The driver 12 generates a drive signal DS to drive the display unit 13 based on the processed video signal IS. The display unit 13 is driven by the drive signal DS and displays the image (e.g., video, still image) represented by the video signal IS.

[0012] The display unit 13 displays an image based on a video signal on the display area 131. The display area 131 has pixels P arranged in a matrix in a first direction (e.g., the Y direction) and a second direction different from the first direction (e.g., the X direction). In the first direction (Y direction), the display color of the pixels P is the same, and in the second direction (X direction), the display color of the pixels P is a periodic repetition of the first to nth display colors (e.g., R (red), G (green), B (blue)) (n: an integer of 3 or more).

[0013] In the example shown in Figure 1, in the display unit 13, the display colors (R, G, B) of pixel P are the same in the first direction (Y direction), and in the second direction (X direction), the display colors of pixel P are a periodic repetition of the first to third display colors R, G, and B (RGB stripe pixel arrangement). The following explanation will proceed using the RGB stripe pixel arrangement as an example.

[0014] However, the configuration of this embodiment may be applied to pixel arrangements other than RGB stripes. For example, in the second direction (X direction) on the display area 131, four or more colors, for example, (1) R, G, B, W (white), or (2) R, G, B, Y (yellow), may be periodically repeated.

[0015] In addition, the configuration of this embodiment may also be applied when the display unit 13 is as follows: (1) or (2).

[0016] (1) When the number of pixels on the display unit 13 is less than the number of pixels on the image data, the resolution of the image in at least one of the X and Y directions will be reduced. Generally, the resolution in the X direction (horizontal direction) is reduced. For example, for image data with 1080 dots × RGB (1080 × 3 dots) in the X direction (horizontal direction) and 1920 dots in the Y direction (vertical direction), the resolution of the display unit 13 is set to 1080 × 2 dots in the X direction, while maintaining 1920 dots in the Y direction. One example of this is SPR (Sub Pixel Rendering).

[0017] (2) In the display area 131, when a pixel P is longer in one of the X and Y directions, and R, G, and B are repeated in order in the other of the X and Y directions (in this case, the X and Y directions are referred to as the first direction and the second direction, respectively) This (2) can be divided into (2a) when a pixel that is longer in the Y direction (vertically elongated) is arranged in the X direction (horizontally elongated) as R, G, and B, and (2b) when a pixel that is longer in the X direction (horizontally elongated) is arranged in the Y direction (vertically elongated) as R, G, and B. For example, this situation may occur when the number of source lines is less than the number of gate lines.

[0018] The control unit 14 controls the display unit 13 and performs the detection process S1 and the averaging process S2, which will be described later.

[0019] Figure 2 is a flowchart showing an example of a display method according to an embodiment of the present invention. The display method includes a detection process S1 and an averaging process S2.

[0020] A. Detection process (S1) Detection process S1 is the process of detecting a region containing a predetermined pattern from the image represented by the video signal.

[0021] This predetermined pattern includes high-gradation pixels (bright pixels, e.g., white pixels) which are pixels P in a predetermined high-gradation range, and low-gradation pixels (dark pixels, e.g., black pixels) which are pixels P in a predetermined low-gradation range. The predetermined high-gradation range and low-gradation range may be, for example, predetermined ranges (e.g., within 10%) from the top and bottom of the gradation range. For example, if the gradation range is 0 to 255, then 230 to 255 and 0 to 25 can be set as the predetermined high-gradation range and low-gradation range, respectively.

[0022] The predetermined pattern has a combination of adjacent high-gradation pixels and low-gradation pixels. When high-gradation pixels and low-gradation pixels are adjacent, the charging and discharging current in the source line or source bus line is more likely to increase due to voltage inversion in the source line or source bus line. As a result, the display quality on the display unit 13 may decrease, the noise generated from the display unit 13 may increase, and the current consumption of the display unit 13 may increase.

[0023] The specified pattern may include the following patterns (1) to (3): (1) A pattern in which high-gradation pixels and low-gradation pixels are arranged alternately in both the first direction (Y direction) and the second direction (X direction); (2) A pattern in which high-gradation pixels in column m1 arranged in the second direction (X direction) and low-gradation pixels in column m1 arranged in the second direction (X direction) (m1: an integer from 1 to 3) are arranged alternately in the first direction (Y direction); (3) A pattern in which high-gradation pixels in column m2 arranged in the first direction (Y direction) and low-gradation pixels in column m2 arranged in the first direction (Y direction) (m2: an integer from 1 to 3) are arranged alternately in the second direction (X direction).

[0024] Pattern (1) can be exemplified by Pattern P1-1, described below. Pattern (2) can be exemplified by Patterns P2-1 to P2-3, described below. Pattern (3) can be exemplified by Patterns P3-1 and P3-2, described below. Note that Patterns P3-1 and P3-2 occur every 1 column and every 3 columns (m2 = 1, 3), but every 2 columns is also acceptable (m2 = 2 is also acceptable).

[0025] These patterns (1) to (3) are just examples of the predetermined patterns, and a variety of other patterns may also be included. Examples of the predetermined patterns will be explained in detail below. Figures 3 and 4 are diagrams that show examples of the predetermined patterns.

[0026] Pattern P1-1 in Figure 3 is an RGB dot staggered arrangement pattern. In pattern P1-1, pixels are arranged alternately in the X and Y directions, with some being bright (high-gradation pixels) and others dark (low-gradation pixels).

[0027] Pattern P1-2 in Figure 3 is a staggered arrangement pattern of two subpixels. In pattern P1-2, in one of the two RGB columns in the X direction, two pixels are light and one is dark, while in the other column, the light and dark states of the pixels are reversed.

[0028] Pattern P1-3 in Figure 3 is a black and white dot arrangement pattern. In pattern P1-3, the three RGB pixels in the X direction alternate between light and dark. Pattern P2-1 in Figure 3 is a black and white horizontal line arrangement pattern. In pattern P2-1, the pixels of one line in the X direction alternate between light and dark.

[0029] Pattern P2-2 in Figure 3 is a pattern with two horizontal lines of black and white. In pattern P2-2, the pixels of the two lines in the X direction alternate between light and dark.

[0030] Pattern P2-3 in Figure 3 is a pattern with three horizontal lines of black and white. In pattern P2-3, the pixels of the three lines in the X direction alternate between light and dark.

[0031] The above patterns P1-1 to P1-3 and P2-1 to P2-3 are applicable to both self-emissive display devices and liquid crystal display devices.

[0032] Pattern P3-1 in Figure 4 is an RGB vertical stripe arrangement pattern. In pattern P3-1, the pixels of one line in the Y direction alternate between light and dark.

[0033] Pattern P3-2 in Figure 4 is a black and white stripe arrangement pattern. In pattern P3-2, the pixels of the three lines in the Y direction alternate between light and dark.

[0034] Patterns P3-1 and P3-2 described above may be applied to either self-emissive display devices or liquid crystal display devices. However, their application may be limited to certain liquid crystal display devices (the 1-line inversion / N-line inversion method described later). Liquid crystal display devices generally use an inversion drive method that inverts the positive and negative voltages of the source line and COM line. Of these, in the alternating inversion method, where the positive and negative voltages are inverted alternately, image degradation due to patterns P3-1 and P3-2 does not occur. However, in the case of a method that does not alternately invert the positive and negative voltages, for example, the 1-line inversion / N-line inversion method, image degradation due to patterns P3-1 and P3-2 may occur.

[0035] The following describes patterns that are not included in the predetermined pattern. Figure 5 is a diagram showing an example of a pattern that is not included in the predetermined pattern.

[0036] Pattern P4-1 in Figure 5 is a pattern that is entirely white. In pattern P4-1, all pixels are in a bright state (high-gradation pixels).

[0037] Pattern P4-2 in Figure 5 is a pattern of four horizontal lines, one black and one white. In pattern P4-2, the pixels of the four lines in the Y direction alternate between light and dark. Pattern P4-2, like patterns P2-1 to P2-3 described above, alternates between light and dark in the Y direction. However, because the number of lines that are switched is large, the effects of display degradation and increased power consumption are reduced, so it does not need to be included in the specified patterns.

[0038] Pattern P4-3 in Figure 5 is a pattern that is entirely gray. Pattern P4-3 does not contain any high-gradation pixels or low-gradation pixels.

[0039] Patterns P4-1 to P4-3 are less likely to cause image degradation and are therefore not included in the predetermined patterns. Similarly, natural images with minimal tonal differences between adjacent pixels are also not included in the predetermined patterns.

[0040] A predetermined pattern may include one or more unit patterns. That is, a predetermined pattern can be constructed by combining unit patterns.

[0041] The unit patterns can be any of the following (1) or (2): (1) A pattern containing 2, 4, or 6 pixels in the first direction (Y direction) and n pixels in the second direction (X direction) (2) A pattern containing 1 pixel in the first direction (Y direction) and 2*n pixels in the second direction (X direction)

[0042] Examples of unit patterns corresponding to the unit pattern (1) include the unit patterns PT1a, PT1b, PT2a to PT2c, PT3a, PT3b, PT4, and PT5 in FIG. 3. Among these, the unit patterns PT1a, PT1b, PT2a to PT2c, PT3a, and PT3b include two pixels in the first direction (Y direction). The unit pattern PT4 includes four pixels in the first direction (Y direction). The unit pattern PT5 includes six pixels in the first direction (Y direction). Examples of unit patterns corresponding to the unit pattern (2) include the unit patterns PT6 and PT7 in FIG. 4.

[0043] The unit pattern may include the same number of high-tone pixels and low-tone pixels in each of the first to nth display colors. The unit patterns PT1a, PT1b, PT2a to PT2c, PT3a, PT3b, PT4, PT5 in FIG. 3 and the unit patterns PT6, PT7 in FIG. 4 all meet this condition.

[0044] Details of the unit pattern will be described below based on FIGS. 3 and 4.

[0045] The pattern P1-1 in FIG. 3 is composed of the unit patterns PT1a and PT1b. In the unit pattern PT1a, among the two columns of RGB pixels, RB in the first column and G in the second column are in the bright state (high-tone pixels), and G in the first column and RB in the second column are in the dark state (low-tone pixels). The unit pattern PT1b is a pattern with the opposite light and dark states to the unit pattern PT1a.

[0046] The pattern P1-2 in FIG. 3 is composed of the unit patterns PT2a to PT2c. In the unit pattern PT2a, among the two columns of RGB pixels, RG in the first column and B in the second column are in the bright state (high-tone pixels), and B in the first column and RG in the second column are in the dark state (low-tone pixels). In the unit pattern PT2b, among the two columns of RGB pixels, GB in the first column and R in the second column are in the bright state (high-tone pixels), and R in the first column and GB in the second column are in the dark state (low-tone pixels). In the unit pattern PT2c, among the two columns of RGB pixels, B in the first column and RG in the second column are in the bright state (high-tone pixels), and RG in the first column and B in the second column are in the dark state (low-tone pixels).

[0047] Pattern P1-3 in FIG. 3 is composed of unit patterns PT3a and PT3b. The unit pattern PT3a is composed of one column of bright-state RGB pixels and one column of dark-state RGB pixels. The unit pattern PT3b is a pattern obtained by inverting the light and dark of the unit pattern PT3a. Pattern P2-1 in FIG. 3 is composed of the unit pattern PT3a.

[0048] Pattern P2-2 in FIG. 3 is composed of the unit pattern PT4. The unit pattern PT4 is composed of two columns of bright-state RGB pixels and two columns of dark-state RGB pixels.

[0049] Pattern P2-3 in FIG. 3 is composed of the unit pattern PT5. The unit pattern PT5 is composed of three columns of bright-state RGB pixels and three columns of dark-state RGB pixels.

[0050] (Details of the detection process) Hereinafter, the details of the detection process will be described. FIG. 6 is a flowchart showing an example of the detection process according to an embodiment of the present invention. FIG. 7 is a plan view showing an example of a pattern according to an embodiment of the present invention. These are examples of detecting the pattern P1-1 (RGB staggered arrangement pattern) as a predetermined pattern.

[0051] Here, the pattern P1-1 is detected based on the following determination criteria 1 to 6. Pixel P1 in the image C1 of FIG. 7 is used as the pixel. - Determination criterion 1: Whether the pixel P1 corresponds to a high-tone pixel or a low-tone pixel (the tone value of the pixel is equal to or greater than the first threshold of a predetermined high-tone range, or equal to or less than the second threshold of a predetermined low-tone range). - Determination criterion 2: Whether the tone difference between the pixel P1 and the pixel P2 adjacent in the horizontal direction (X direction) (the pixel adjacent by one) is the difference between the first threshold and the second threshold (hereinafter referred to as "predetermined tone difference"). - Determination criterion 3: In the horizontal direction, whether the continuous repetition count mx of pixels with a predetermined tone difference is greater than a predetermined first count. - Determination criterion 4: Whether the tone difference between the pixel P1 and the pixel P3 adjacent in the vertical direction (Y direction) (the pixel one below) is equal to or greater than the predetermined tone difference. - Determination criterion 5: In the vertical direction, whether the continuous repetition count my of pixels with a predetermined tone difference is greater than a predetermined second count.

[0052] In step S11, the gradation value of the pixel P1 is compared with the first and second thresholds according to the determination criterion 1 to determine whether the pixel corresponds to a high-gradation pixel or a low-gradation pixel. If the determination result is "YES", the process proceeds to step S12. If the determination result is "NO", the process returns to step S11 and the determination is made for the next pixel in the horizontal direction of the pixel.

[0053] In step S12, the grayscale values ​​of the pixel P1 and its adjacent horizontal pixel P2 are compared according to the determination criterion 2. If the determination result is "YES", the process proceeds to step S13. If the determination result is "NO", the process returns to step S11, and the determination is made for the next pixel horizontally to the pixel P1.

[0054] In step S13, it is determined according to criterion 3 whether the number of horizontal movements is greater than a predetermined first number. If the result of this determination is "YES", the process proceeds to step S14. If the result of this determination is "NO", the process returns to step S11, and the determination is made for the next pixel in the horizontal direction of the pixel in question.

[0055] In step S14, it is determined whether the analysis of the first line of the pixel is complete. If the result of this determination is "YES", the process proceeds to step S15. If the result of this determination is "NO", the process returns to step S11, and the determination is made for the next pixel in the horizontal direction of the pixel in question.

[0056] In step S15, the same determination as in steps S11 to S14 is made for the next line. Once step S15 is complete, proceed to step 16.

[0057] In step S16, the grayscale values ​​of the pixel P1 and its adjacent vertical pixel P3 are compared according to the determination criterion 4. If the determination result is "YES", the process proceeds to step S17. If the determination result is "NO", the process returns to step S11, and the determination is made for the next pixel horizontally to the pixel in question.

[0058] In step S17, it is determined according to criterion 5 whether the number of vertical movements is greater than a predetermined second number of movements. If the result of this determination is "YES", the process proceeds to step S18. If the result of this determination is "NO", the process returns to step S11, and the determination is made for the next pixel in the horizontal direction of the pixel in question.

[0059] In step S18, it is determined whether the analysis of the final line of the pixel is complete. If the result of this determination is "YES", the process proceeds to step S19. If the result of this determination is "NO", the process returns to step S11, and the determination is made for the next pixel in the horizontal direction of the pixel in question.

[0060] In step S18, it is determined that a region A containing a predetermined pattern (pattern P1-1: RGB dot staggered arrangement pattern) has been detected.

[0061] As described above, a predetermined pattern (pattern P1-1) can be detected based on judgment criteria 1 to 5. Similar judgment criteria can also be set for other patterns to detect areas containing the predetermined pattern. For example, this area can be determined based on the first and second counts (thresholds) of each line (vertical and horizontal) of the judgment criteria 3 and 5 described above.

[0062] Furthermore, even if criteria 1 to 5 are partially not met, it may still be determined that a predetermined pattern has been detected. For example, if the number of consecutive repetitions in the vertical direction is 200, and there are 300 repetitions including 5 instances where the number of repetitions was not met, it may be determined that a region containing the predetermined pattern has been detected.

[0063] Figure 8 is a flowchart illustrating another example of the detection process according to an embodiment of the present invention. Here, a predetermined pattern is detected using a unit pattern.

[0064] (1) Extraction of regions composed of high-gradation pixels and low-gradation pixels (Step S31) Regions composed of high-gradation pixels and low-gradation pixels are extracted from the image. For example, pixels having a predetermined high-gradation range or low-gradation range are extracted from the pixels on the image, and regions where the extracted pixels are accumulated are identified.

[0065] (2) Division of the extracted region (Step S32) The extracted region is divided. For example, the region is divided based on the size of the unit pattern. For example, the region is divided into 3 x 2 dots according to the unit patterns PT1a to PT1c, PT2a to PT2c, PT3a, and PT3b (divided region). Alternatively, the region may be divided into 3 x 4 dots and 3 x 6 dots corresponding to the unit patterns PT4 and PT5, respectively. Alternatively, the region may be divided into 6 x 1 dots corresponding to the unit patterns PT6 and PT7.

[0066] (3) Determination of matching unit patterns of divided areas (Step S32) It is determined whether the divided areas match a unit pattern. For example, it is determined whether a 3x2 dot divided area matches any of the unit patterns PT1a to PT1c, PT2a to PT2c, PT3a, or PT3b. It is determined whether a 3x4 dot divided area matches unit pattern PT4. It is determined whether a 3x6 dot divided area matches unit pattern PT5. It is determined whether a 6x1 dot divided area matches unit pattern PT6 or PT7.

[0067] (4) Detection of a predetermined pattern (Step S32) A predetermined pattern is detected as an accumulation of divided regions that match a unit pattern. For example, pattern PT1-1 is detected as a combination of unit patterns PT1a and PT1b. By determining the combination of unit patterns, regions that match any of patterns P1-1 to PT1-3, P2-1 to PT2-3, P3-1, and PT3-2 can be extracted from the region.

[0068] However, instead of determining this combination, any region composed of an accumulation of any unit region may be detected as a region containing a predetermined pattern.

[0069] B. Averaging Process (S2) The averaging process S2 is a process that averages the gradation of pixels within a region. Figure 9 is a plan view showing an example of the averaging process according to an embodiment of the present invention. Images BA and AA represent the image before and after the averaging process, respectively. As shown in Figure 9, the averaging image has approximately the same gradation values ​​(luminance and hue) for pixels within the region. Here, as a result of averaging 255 gradations and 0 gradations in terms of luminance, the gradation of the pixels is averaged to 186 gradations.

[0070] The display area 131 of the display unit 13 is generally high-resolution, and there is a certain distance between the viewer and the display area 131. For this reason, viewers tend to perceive images that include repetitions of high-gradation pixels and low-gradation pixels within a few pixels as images with average gradation. As a result, whether images with high-gradation pixels and low-gradation pixels are displayed as they are, or images with averaged mid-tones are displayed, the difference becomes practically imperceptible. Thus, the visual degradation of the display due to the averaging process S2 does not occur in practice.

[0071] This averaging may involve averaging the number of gradations themselves, or it may be done on luminance based on a gamma curve GC, as shown in Figure 9. Figure 10 shows an example graph representing an example of a gamma curve GC. As shown in Figure 10, the gamma curve GC correlates gradation values ​​with luminance. Here, the gradation range is set to 0 to 255.

[0072] When the luminance of a gradation value of 0 (luminance ratio 0%) and the luminance of a gradation value of 255 (luminance ratio 100%) are averaged, the luminance ratio becomes 50%, and the gradation value at this point becomes 186, which does not match the average gradation value of 127.5 (= (0 + 255) / 2). Thus, considering the viewer's visibility, averaging the number of gradations based on the gamma curve GC is preferable. That is, the number of gradations is converted to luminance (or luminance ratio) to obtain the average luminance, and this average luminance is converted to the number of gradations (average gradation considering luminance).

[0073] This gamma curve GC can be stored in the storage unit 15 as a table representing the relationship between the number of gray levels and brightness. The control unit 14 can use this table to perform the averaging process S2. Instead of this table, the display device 10 may have hardware for calculations that can perform calculations of brightness from the number of gray levels and the inverse calculation.

[0074] The control unit 14 may, for example, execute the averaging process S2 if the pattern detected in the detection process S1 includes a number of pixels greater than a predetermined first number in a first direction, and a number of pixels greater than a predetermined second number in a second direction.

[0075] In other words, the decision of whether or not to perform the averaging process may be made based on the size of the detected region. Here, the presence or absence of the averaging process S2 is determined based on a reference size, which is determined by a predetermined first number in the first direction and a predetermined second number in the second direction. For example, the first and second numbers can be set to numbers of about 100 to 500 (200 as an example).

[0076] The reference size may be set, for example, based on the size of the display area 131 of the display unit 13. For example, the reference size (reference number of pixels) may be set to a number of pixels that is 1 / 16 or more (6.25% or more) of the size (number of pixels) of the display area 131. In this case, the averaging process S2 is executed when the number of pixels in the detected area is greater than the reference number of pixels. On the other hand, the averaging process S2 is not executed when the number of pixels in the detected area is less than or equal to the reference number of pixels.

[0077] In this case, multiple regions divided into two parts may be detected. In this case, (1) it may be determined whether the number of pixels in each of these divided regions is equal to or greater than the reference number of pixels (for example, at least 1 / 16 (6.25% or more) of the size (number of pixels) of the display area 131), or (2) it may be determined whether the sum of the number of pixels in these divided regions is greater than the reference number of pixels.

[0078] In the averaging process S2, the control unit 14 may divide the region detected in the detection process S1 into a plurality of sub-regions and average the grayscale for each of the plurality of sub-regions.

[0079] The size of this sub-region can be set as appropriate. For example, the sub-region may be set as two columns of 3 pixels each of RGB, or as four columns of 6 pixels each of RGBRGB.

[0080] Furthermore, the size of this sub-region can be the size of the unit pattern. For example, in step S32 of step S1, the extracted region may be divided based on the unit pattern, and in step S2, the gradation may be averaged for each of these divided regions.

[0081] The following shows the patterns before and after the averaging process. Figure 11 is a schematic diagram representing an example of the averaging process according to an embodiment of the present invention.

[0082] The upper part of Figure 11 shows that an averaging process is performed using two columns of 3 pixels each of RGB as the unit. In this process, an averaging process S2 is performed using the unit pattern P1a as the unit to generate the averaged pattern P1g.

[0083] In the lower part of Figure 11, averaging is performed using four columns of 6 pixels each of RGBRGB as the unit. This process is equivalent to performing averaging S2 using four unit patterns P4a as the unit to generate four averaged patterns P4g.

[0084] As described above, the display device according to this embodiment includes a display unit 13 that displays an image based on a video signal, and a control unit 14 that controls the display unit 13. The control unit 14 performs a detection process S1 to detect a region from the image represented by the video signal that includes high-gradation pixels, which are pixels within a predetermined high-gradation range, and low-gradation pixels, which are pixels within a predetermined low-gradation range, and that includes a pattern having a combination of adjacent high-gradation pixels and low-gradation pixels. The control unit 14 also performs an averaging process to average the gradation of the pixels within the region.

[0085] By detecting regions containing patterns with combinations of adjacent high-gradation pixels and low-gradation pixels, and averaging the gradation of pixels within these regions, the displayed image is modified to be less prone to display quality degradation. As a result, a display device and display method can be realized that reduce the need for individual drive control of each pixel (for example, individually controlling the drive transistors) to prevent display quality degradation.

[0086] [Example of implementation by software] The functions of the display device 10 (hereinafter referred to as "device") can be realized by a program that causes a computer to function as the device, and by a program that causes a computer to function as each control block (particularly the control unit 14) of the device.

[0087] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a storage unit 15, for example, memory) as hardware for executing the program. By executing the program using this control device and storage device, each of the functions described in each of the embodiments is realized.

[0088] The above program may be recorded on one or more computer-readable recording media, not temporary ones. These recording media may or may not be provided by the above device. In the latter case, the program may be supplied to the above device via any wired or wireless transmission medium.

[0089] Furthermore, some or all of the functions of each of the above control blocks can also be realized by logic circuits. For example, an integrated circuit in which logic circuits functioning as each of the above control blocks are formed is also included in the scope of the present invention. In addition, it is also possible to realize the functions of each of the above control blocks by, for example, a quantum computer.

[0090] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0091] 10 Display device 11 Video signal processing unit 12 Driver 13 Display unit 14 Control unit 15 Storage unit 131 Display area

Claims

1. A display device comprising: a display unit that displays an image based on a video signal; and a control unit that controls the display unit, wherein the control unit performs a detection process to detect a region from the image represented by the video signal that includes high-gradation pixels which are pixels within a predetermined high-gradation range, and low-gradation pixels which are pixels within a predetermined low-gradation range, and that has a pattern of combinations of adjacent high-gradation pixels and low-gradation pixels; and an averaging process which averages the gradation of pixels within the region.

2. The display device according to claim 1, wherein the image has pixels arranged in a matrix in a first direction and in a second direction different from the first direction, the display color of the pixels is the same in the first direction, and the display color of the pixels in the second direction is a periodic repetition of the first to nth display colors (n: an integer of 3 or more).

3. The display device according to claim 2, wherein the pattern includes one or more unit patterns, and the unit pattern includes (1) two, four, or six pixels in the first direction and n pixels in the second direction, or (2) one pixel in the first direction and 2 * n pixels in the second direction.

4. The display device according to claim 3, wherein the unit pattern includes the same number of high-gradation pixels and low-gradation pixels in each of the first to nth display colors.

5. The display device according to claim 2, wherein the pattern is any of the following: (1) a pattern in which high-gradation pixels and low-gradation pixels are arranged alternately in both the first and second directions; (2) a pattern in which m1 rows of high-gradation pixels arranged in the second direction and m1 rows of low-gradation pixels arranged in the second direction (m1: an integer from 1 to 3) are arranged alternately in the first direction; or (3) a pattern in which m2 rows of high-gradation pixels arranged in the first direction and m2 rows of low-gradation pixels arranged in the first direction (m2: an integer from 1 to 3) are arranged alternately in the second direction.

6. The display device according to any one of claims 2 to 5, wherein the control unit performs the averaging process when the pattern detected in the detection process includes a number of pixels greater than a predetermined first number in the first direction and a number of pixels greater than a predetermined second number in the second direction.

7. The display device according to any one of claims 1 to 6, wherein the control unit divides the region detected in the detection process into a plurality of sub-regions and averages the gradation for each of the plurality of sub-regions.

8. The display device according to any one of claims 1 to 7, wherein the display device is a self-illuminating display device or a liquid crystal display device.

9. A display method for displaying an image based on a video signal, comprising: a detection process for detecting a region from the image represented by the video signal that includes a pattern having a combination of adjacent high-gradation pixels and low-gradation pixels, which include high-gradation pixels that are pixels within a predetermined high-gradation range and low-gradation pixels that are pixels within a predetermined low-gradation range; and an averaging process for averaging the gradation of pixels within the region.

Images