JP2012008202A - Display device - Google Patents

Abstract

Processing for generating and displaying display data for each sub-pixel is performed to enable high-resolution expression. At this time, video display with optimum video quality is performed according to the characteristics of the video content.
A display device includes a display panel in which one pixel is composed of sub-pixels of four colors, generates display data based on an input video signal for each of the sub-pixels, and displays the display data on the display panel. In addition, the high-luminance subpixels are arranged separately in one pixel, and the area of each of the high-luminance subpixels in one pixel is smaller than that of the other subpixels. The RGBY four primary color sub-pixels preferably have a pixel configuration 104 in which the high-luminance G and Y are separated and the sub-pixels are arranged in the order of RGBY, for example. Thus, processing for improving the resolution is performed. Then, according to the setting of the image quality mode of the display device, the processing for improving the resolution is turned OFF or ON.
[Selection] Figure 3

Description

  The present invention relates to a display device, and more particularly to a display device that supports multi-primary color display such as RGBY.

  2. Description of the Related Art Conventionally, various types of displays that form images with pixels have been commercialized as display means for displaying information and video. For example, one pixel is generally composed of sub-pixels (sub-pixels) of three primary colors composed of red (R), green (G), and blue (B), and thus color display is generally performed. Color filters are usually used to realize these subpixels. In such a color display technology, in recent years, it has been studied to expand color reproducibility in order to improve display quality.

  On the other hand, by increasing the number of primary colors to four or more primary colors using new colors other than the three primary colors of RGB, the area on the chromaticity diagram for chromatic colors is expanded or the luminance efficiency is improved. So-called multi-primary color displays have been developed. For example, an RGBY pixel configuration in which Y (yellow) is added to RGB and an RGBW pixel configuration in which W (white) is added to RGB are being studied.

  On the other hand, there is a sub-pixel sampling technique for sampling an input video signal in units of sub-pixels constituting a pixel in order to improve display resolution characteristics and perform high-definition video expression. In the subpixel sampling technique, for example, with respect to a pixel composed of three subpixels of RGB, each subpixel is regarded as one pixel, and the luminance is reproduced for each subpixel. Here, if RGB are arranged in the horizontal direction, sampling is performed by setting the horizontal sampling frequency to three times that of the conventional method. The subpixels are driven based on the signals corresponding to the sampled RGB subpixels.

  For example, Patent Document 1 discloses a technique for increasing the resolution of a rendered black-and-white text or graphics image and reducing the color edge. Here, a grayscale image is interleaved three times in the horizontal direction, and low-pass filtering is performed to create and display RGB image data.

JP 2001-117529 A

  When an input video signal is sampled and video representation is performed using digital data, a phenomenon in which video quality is deteriorated generally occurs in the process of processing a digital image. For example, in the frequency axis direction, interference fringes (beats) are generated due to a signal having a Nyquist frequency equal to or higher than ½ of the sampling frequency turning back to a low frequency. There is also a problem such as color misregistration (color aliasing) that occurs because the apparent RGB gradation changes with respect to the input.

  These problems can be suppressed to some extent by setting a sampling frequency suitable for the quality of the input video and performing appropriate digital processing. However, sufficient video quality may not always be maintained due to factors such as pixel arrangement and sampling method. For example, when trying to improve the resolution characteristics by sub-pixel sampling on a general display that expresses the three primary colors of RGB as one pixel, for example, an image with a high spatial frequency such that white and black are alternately arranged When the is input, the degradation of video quality due to beats may be noticeable.

  In other words, it is possible to perform high-resolution expression by generating and displaying display data for each of the sub-pixels, but at this time, it is necessary to have a technical idea that does not cause deterioration in video quality. Become.

  Even when subpixel sampling is performed as described above, for example, a video having a characteristic characteristic peculiar to the content such as a movie, a game, animation, or a video output from a PC (Personal Computer). On the other hand, not only the sub-pixel sampling is performed uniformly, but also high-resolution processing can be executed with optimal video quality by performing optimal video processing according to the characteristics of the video content.

  The present invention has been made in view of the circumstances as described above, and enables high-resolution expression by performing processing for generating and displaying display data for each of the sub-pixels, and at this time, depending on the characteristics of the video content. An object of the present invention is to provide a display device capable of displaying an image with optimum image quality.

  In order to solve the above problems, a first technical means of the present invention is a display device having an image quality mode for displaying an image with an optimum image quality according to the type of input video signal. A display panel in which one pixel is configured by color sub-pixels, and a display control unit that performs processing for generating a video signal to be displayed on the display panel from the input video signal, and the display control unit includes: Display data based on the input video signal is generated for each subpixel, and the display data is displayed on the display panel to improve the resolution of the display image, and display data based on the input video signal is generated on a pixel basis. The processing for improving the resolution of the display image is turned OFF or ON according to the setting of the image quality mode. Is obtained by it said.

  According to a second technical means, in the first technical means, as the image quality mode, a movie mode for optimally displaying a movie, a standard mode for displaying an image with a standard image quality, and a clear and vivid image are displayed. At least one of a dynamic mode for displaying and a game mode for optimally displaying a video of a game, and the display control unit is configured such that the image quality mode set in the display device is the movie mode. In the case of any one of the standard mode, the dynamic mode, and the game mode, the process for improving the resolution is turned on.

  According to a third technical means, in the first or second technical means, the image quality mode includes a PC mode for optimally displaying an image output from a personal computer and an animation mode for optimally displaying an animation. And the display control unit turns off the processing for improving the resolution when the image quality mode set in the display device is the PC mode or the animation mode. It is what.

  According to a fourth technical means, in any one of the first to third technical means, the display panel includes two high-luminance sub-pixels out of the four sub-pixels, and the other two low-color sub-pixels. The luminance is at least twice as high as the luminance of the luminance sub-pixel, and the high-luminance sub-pixels are arranged apart from each other in the one pixel.

  According to a fifth technical means, in the fourth technical means, the high-luminance sub-pixel and other sub-pixels other than the high-luminance sub-pixel are alternately arranged. .

  Sixth technical means is characterized in that, in the fourth or fifth technical means, the area of each of the high-luminance sub-pixels in the one pixel is smaller than that of the other sub-pixels. It is a thing.

  A seventh technical means is any one of the fourth to sixth technical means, wherein the four color sub-pixels are sub-pixels of four colors of red, green, blue and yellow, It is characterized by having green and yellow sub-pixels as sub-pixels.

  According to the present invention, processing for generating and displaying display data for each sub-pixel is performed to enable high-resolution expression, and at this time, video display with optimal video quality is performed according to the characteristics of the video content. A display device can be provided.

It is the figure which showed typically the structural example of the display part of the liquid crystal display device which can apply this invention. 1 is a block diagram of a liquid crystal display device to which the present invention can be applied. It is a figure for demonstrating the resolution obtained according to the structure of a sub pixel. It is a figure for demonstrating pixel sampling and subpixel sampling.

  FIG. 1 is a diagram schematically showing a configuration example of a display unit of a liquid crystal display device to which the present invention can be applied, and shows a display unit 1 having a RGBY pixel configuration. Here, one pixel 11 has an RGBY pixel configuration. That is, each pixel of the color image displayed by the display unit 1 is R sub-pixel, G sub-pixel, B sub-pixel corresponding to R (red), G (green), B (blue), and Y (yellow), respectively. It consists of Y subpixels. Note that the arrangement order of the sub-pixels can be appropriately changed as long as an arrangement condition described later is satisfied, and may be an order such as YRGB.

  The same applies to the RGB pixel configuration and the RGBW pixel configuration. In the case of RGB, one pixel 11 is composed of RGB sub-pixels. In the case of RGBW, one pixel 11 is sub-RGBW sub-pixel. Consists of pixels.

FIG. 2 is a block diagram of a liquid crystal display device to which the present invention can be applied. This block diagram shows a video display control portion of the liquid crystal display device, which has a conventional pixel configuration in which one pixel is composed of RGB sub-pixels, a multi-primary pixel configuration such as RGBY, or RGBW. The present invention can also be applied to a pixel configuration.
The liquid crystal display device includes a display unit 1, an input unit 2, a video processing circuit 3, a control unit 4, a light source control circuit 5, and a drive control circuit 6. The display unit 1 includes an active matrix type color display panel, and the drive control circuit 6 generates a drive signal for driving the display unit 1.

The input unit 2 is an interface for inputting a video signal such as a digital broadcast signal. The video processing circuit 3 executes various signal processes on the input video signal from the input unit 2.
The video processing circuit 3 performs video processing according to the image quality mode selected in accordance with a user operation of an operation input unit (not shown). The image quality mode is a mode for optimizing the brightness and contrast of the screen so that the quality is suitable for the content viewed by the user.

  The control unit 4 includes a CPU and a memory that control the operation of the liquid crystal display device. The light source control circuit 5 adjusts the luminance of the backlight light source by controlling the power supplied to the backlight light source constituting the display unit 1 in accordance with a control command from the control unit 4.

  The display unit 1 includes a color filter 7, a liquid crystal panel body 8, and a backlight light source 9. The liquid crystal panel body 8 is formed with a plurality of data signal lines and a plurality of scanning signal lines intersecting therewith. The liquid crystal panel body 8 and the color filter 7 constitute a color liquid crystal panel including a plurality of pixel forming portions arranged in a matrix. The backlight light source 9 is a light source that illuminates the liquid crystal panel body 8.

  The display unit 1 having an RGBY pixel configuration will be described as an example. The drive control circuit 6 includes a display control circuit 61, a data signal line drive circuit 13, and a scanning signal line drive circuit 14. The display control circuit 61 corresponds to the display control unit of the present invention. The display control circuit 61 receives the data signal DAT (Ri, Gi, Bi) from the video processing circuit 3 and the timing control signal TS from a timing controller (not shown), and receives the digital video signal. DV (Ro, Go, Bo, Yo), data start pulse signal SSP, data clock signal SCK, latch slope signal LS, gate start pulse signal GSP, gate clock signal GCK, and the like are output.

  Each pixel 11 of the display unit 1 is composed of RGBY sub-pixels, and the data signal DAT is composed of three primary color signals (Ri, Gi, Bi) respectively corresponding to the three primary colors of red, green, and blue. The display control circuit 61 converts an input primary color signal (Ri, Gi, Bi) corresponding to the three primary colors of RGB into an output primary color signal (Ro, Go, Bo, Yo) corresponding to the four primary colors of RGBY. Is provided. The digital video signal DV is an output primary color signal (Ro, Go, Bo, Yo) output from the conversion circuit 62, and thereby displays a color image to be displayed on the display unit 1.

  The data start pulse signal SSP, the data clock signal SCK, the latch strobe signal LS, the gate start pulse signal GSP, the gate clock signal GCK, and the like are timing signals for controlling the timing for displaying an image on the display unit 1. It is.

  The data signal line drive circuit 13 receives the digital image signal DV (Ro, Go, Bo, Yo), the data start pulse signal SSP, the data clock signal SCK, and the latch strobe signal LS output from the display control circuit 61, and displays them. In order to charge the pixel capacitance in each sub-pixel of the unit 1, a data signal voltage is applied as a drive signal to the data signal line of each pixel.

Based on the gate start pulse signal GSP and the gate clock signal GCK output from the display control circuit 61, the scanning signal line driving circuit 14 activates an active scanning signal (a scanning signal for turning on the TFT) on the scanning signal line in the display unit 1. Voltage) is applied sequentially.
As a result, a voltage corresponding to the digital video signal DV is held in the pixel capacitance of each sub-pixel and applied to the liquid crystal layer. As a result, a color image represented by the digital video signal DV is displayed on the display unit 1 by RGBY color filters provided in each sub-pixel.

  The display control circuit 61 generates display data based on the input video signal for each of the sub-pixels, and displays the display data on the display unit 1 to improve the resolution of the display image, and the input video signal in units of pixels. It is possible to switch between processing for generating display data based on. That is, high resolution processing by subpixel sampling and conventional pixel sampling processing are switched and executed. The process is switched according to the image quality mode of the display device as will be described later.

FIG. 3 is a diagram for explaining the resolution obtained according to the configuration of the sub-pixels. The horizontal axis of FIG. 3 shows the spatial frequency obtained by each subpixel configuration.
Here, a monochrome first pixel configuration 101, a second pixel configuration 102 with three RGB subpixels, a third pixel configuration 103 with RGBY subpixels, and a fourth pixel configuration 104 with RGBY subpixels. , Comparing. Here, the third pixel configuration 103 has a 1: 1: 1: 1 configuration in which the areas of the RGBY sub-pixels are the same. In the fourth pixel configuration 104, the area ratio of RGBY sub-pixels is R: B: G: Y = 1.6: 1.0: 1.6: 1.0.

For example, a full high-definition (HD) panel having a horizontal direction of 1920 pixels is assumed. Here, assuming 1 pixel / dot as a reference, in the case of the monochrome first pixel configuration 101, the spatial frequency indicating the pixel resolution is Fn. Here, in the full HD panel, 1920 pixels = 1920 dots, which has a resolution equivalent to 1 pixel.
In the case of the second pixel configuration 102 using RGB sub-pixels, since one pixel is composed of three sub-pixels having an equal area, the spatial frequency is 3 times 3Fn. In a full HD panel, 1920 pixels × 3 subpixels = 5760 dots, which is a resolution equivalent to 0.33 pixels.

  In the case of the third pixel configuration 103 using RGBY sub-pixels, one pixel is composed of four sub-pixels having an equal area, so that the spatial frequency is 4Fn, which is four times that of monochrome. . In a full HD panel, 1920 pixels × 4 subpixels = 7680 dots, which is a resolution equivalent to 0.25 pixels. Therefore, in the case of the third pixel configuration 103 of RGBY, the resolution is 1.33 times smaller than that of the second pixel configuration 102 of RGB.

Further, in the case of the fourth pixel configuration 104 with RGBY sub-pixels, one pixel has four ratios of R: G: B: Y = 1.6: 1.0: 1.6: 1.0. It consists of sub-pixels. Therefore, the spatial frequency of R and B having a ratio of 1.6 is Fn × 5.2 / 1.6 = 3.25Fn. The spatial frequency of G and Y having a ratio of 1.0 is Fn × 5.2 / 1.0 = 5.2Fn.
In a full HD panel, in the case of R and B sub-pixels, 1920 × 5.2 / 1.6 = 6240 dots, which is a resolution equivalent to 0.31 pixels. In the case of G and Y sub-pixels, 1920 pixels × 5.2 / 1.0 = 9984 dots, which is a resolution equivalent to 0.19 pixels. Accordingly, in the case of the R and B subpixels, the resolution is 1.08 times finer than that of the RGB second pixel configuration 102, and in the case of the G and Y subpixels having a small area, the RGB second pixel. The resolution is 1.73 times smaller than that of the configuration 102.

  In the embodiment according to the present invention, one picture element is composed of RGBY sub-pixels, and good pixel quality can be obtained by performing sub-pixel sampling. Here, in the embodiment according to the present invention, for example, it is important that one pixel is arranged in the order of RGBY. The reason is that among the RGBY, the G and Y sub-pixels having a high luminance ratio are arranged apart from each other. When the brightness of G and Y, which are high brightness, is sufficiently larger than the brightness of R and B, the brightness center becomes two by the high brightness sub-pixel that controls the brightness within one pixel, and the resolution is improved. Can do. In other words, by arranging in the order of RGBY, G and Y having a high luminance ratio from RGBY are arranged apart from each other without being adjacent to each other, thereby achieving the same effect as when the spatial resolution is increased, and video quality is achieved. Can be improved. Here, since the luminance of G and Y is high, the same effect can be obtained even with an arrangement of YRGB, GRYB, RYBG, or the like.

  Whether or not the luminance of the sub-pixel is sufficiently large is determined based on whether or not the luminance of the sub-pixel is twice or more that of the other sub-pixels. The reason for this is that G, which has a dominant luminance, has about five times the luminance of B and about two times the luminance of R in RGB configuration pixels. Here, it is said that the luminance is sufficiently large when the luminance of G and Y is at least twice that of R and B. That is, in the embodiment according to the present invention, two high-luminance sub-pixels out of four sub-pixels have at least twice the luminance of the other two low-luminance sub-pixels. It is necessary that high-luminance sub-pixels are arranged apart from each other in one pixel.

More specifically, in the configuration in which four subpixels are arranged, a subpixel having at least twice the luminance of the other subpixels is set as a high-luminance subpixel that is dominant in luminance. High luminance sub-pixels and other sub-pixels are alternately arranged. Thereby, in the configuration in which the pixels are continuously arranged, the high-luminance sub-pixels are alternately arranged, and the resolution is improved in the arrangement direction.
Further, even in the direction orthogonal to the subpixel arrangement direction, the resolution of the entire pixel matrix can be improved by alternately arranging the high-luminance subpixels and the other subpixels.

  The configuration in which the high-luminance subpixels and the other subpixels are alternately arranged is not limited to the RGBY arrangement. For example, it does not prevent the adoption of the RGBW arrangement or the RYBG arrangement.

Further, in the embodiment of the display device according to the present invention, the area of each of the high-intensity sub-pixels described above is made smaller than the other sub-pixels in one pixel. For example, the area ratio of RGBY in the pixel is R: G: B: Y = 1.6: 1.0: 1.6: 1.0.
As described above with reference to FIG. 3, in the case of the fourth pixel configuration 104 in which RGBY is arranged in an area ratio of 1.6: 1.0: 1.6: 1.0, 0 is set for R and B. It can be seen that a resolution equivalent to .31 pixels can be obtained, and for G and Y, a resolution equivalent to 0.19 pixels can be obtained. The apparent resolution can be improved by reducing the area ratio of the high-luminance sub-pixels. Therefore, in the embodiment according to the present invention, the area of the high-luminance subpixel that is dominant in luminance is made smaller than the areas of the other subpixels.

That is, the processing by the sub-pixel sampling 12 for improving the resolution executable in the embodiment of the display device according to the present invention is based on the following.
(1) In the display panel, one pixel is constituted by subpixels of four colors, and display data based on the input video signal is generated and displayed for each of the subpixels.
(2) Of the four color sub-pixels, two high-luminance sub-pixels have at least twice the luminance of the other two-color low-luminance sub-pixels, and within one pixel, High luminance sub-pixels are arranged apart.
(3) A high-luminance subpixel and other subpixels other than the high-luminance subpixel are alternately arranged in one pixel.
(4) Within each pixel, the area of each of the high-luminance sub-pixels is made smaller than that of the other sub-pixels.
(5) RGBY sub-pixels are used as the four-color sub-pixels, and the sub-pixels are arranged in the order of RGBY, YRGB, GRYB, RYGB, etc. Yes.
And with such a sub-pixel arrangement, processing of generating video data for each sub-pixel by sub-pixel sampling etc., and performing video representation, it is possible to express high resolution and improve degradation of video quality A display device can be provided.

4A and 4B are diagrams for explaining pixel sampling and sub-pixel sampling. FIG. 4A is a diagram for explaining the state of pixel sampling, and FIG. 4B is a diagram for explaining the state of sub-pixel sampling. . Here, the horizontal axis indicates the pixel position in the X direction, and the vertical direction indicates the pixel value.
In the pixel sampling shown in FIG. 3A, sampling is performed at one position for each pixel (pixel) with respect to an analog input video signal (input). For example, the input video signal is sampled at a position corresponding to RGB G of each pixel. If the pixel pitch at this time is Δx, the sampling frequency fs is fs = 1 / Δx. Then, the sampled pixel data is assigned to all of RGB and displayed. Accordingly, the RGB pixel value of each pixel is the same value. This technique is pixel sampling.

  In the case of pixel sampling, the R and B subpixels located on both sides of the G subpixel are spatially shifted by ± Δx / 3. Here, each of the input video signals corresponding to the sub-pixels has luminance and color. However, by performing pixel sampling, luminance components are dispersed and the spatial frequency characteristics are dull. In addition, color components are dispersed to cause color shift and distortion.

  In order to improve the dullness and distortion due to pixel sampling as described above, methods such as sub-pixel rendering have been devised. In subpixel rendering, a signal sampled by pixel sampling is interpolated between sampling points to create data of each subpixel, thereby spatially smoothing between the sampling points.

  The subpixel sampling shown in FIG. 4B does not create subpixel data by interpolating the data sampled in units of subpixels as described above, but actually samples the input video signal at subpixel intervals. Data can be obtained, and data faithful to the input video signal can be obtained. Here, the input video signal is sampled at a sampling frequency fx corresponding to a sub-pixel unit. In this case, the R subpixel is shifted by Δx / 3 from the G subpixel, and the B subpixel is sampled by shifting by −Δx from the G subpixel, and the pixel value is assigned.

  The processing according to the present invention for generating display data based on the input video signal for each of the subpixels can be applied to both the subpixel sampling processing and the subpixel rendering processing described above.

As a feature of the present invention, the processing for improving the resolution by subpixel sampling as described above is turned on or off according to the setting of the image quality mode of the display device.
Conventionally, in a display device such as a television device, an image quality mode that can be set by a user can be set as a video display mode. The image quality mode is a mode for optimizing the brightness and contrast of the screen so that the quality is suitable for the content viewed by the user.

  Examples of image quality modes include movie mode for optimally displaying movies, standard mode for displaying images with standard image quality, dynamic mode for displaying clear and vivid images, and optimal game images A game mode for displaying an image, a PC mode for optimally displaying an image output from the PC, an animation mode for optimally displaying an animation, and the like are set.

For example, in the movie mode, emphasis is placed on faithfully reproducing the image, and in order to express more realistic black, the dark image of the movie is made easier to see by suppressing the contrast.
The standard mode is a mode in which all video and audio settings are set to predetermined standard values, and is conscious of being used mainly at home. Emphasis on expressing. In addition, assuming that the frequency of use is high, settings are made so that a certain amount of power saving can be achieved.

  In the dynamic mode, emphasis is placed on making the video appear brighter and clearer than the standard, and black is tightened. This makes it possible to make sports programs and the like particularly powerful with clear and vivid display. In the game mode, the video of a video game or the like is made into a video that is easy on the eyes with reduced brightness. It can also handle games that require a quick response. The PC mode and the animation mode are set so that images output from the PC and animation images can be easily seen with the optimum image quality.

  In the processing for improving the resolution, the luminance is adjusted in units of subpixels in order to improve the luminance resolution. However, for example, in the case of an image with few color types and close to black and white, color adjustment on the screen may become conspicuous by adjusting the luminance in units of subpixels, and depending on the image, a large effect cannot be exhibited. In some cases. On the other hand, a large effect can be expected in the case of an image that contains many colors such as a natural image. In addition, for example, when displaying an image of a geometrical screen structure with a clear edge such as an image output from a PC by dot-by-dot, control is performed to improve resolution by sampling in sub-pixel units. However, the effect is not so great.

  For these reasons, in the embodiment according to the present invention, the processing for improving the resolution by the sub-pixel sampling as described above is turned on / off according to the image quality mode set in the display device. According to the video to be displayed, resolution improvement control by subpixel sampling is effectively executed.

Of the image quality modes set on the display device, the image quality modes for turning on the processing for improving the resolution are the movie mode, the standard mode, the dynamic mode, and the game mode. Even if the display device does not have all of these image quality, if one or more of these image quality modes can be set, the processing for improving the resolution is turned on in the image quality mode. .
In any of the movie mode, the standard mode, and the dynamic mode, a natural image is displayed. In the case of a natural image expressed by a large number of colors, the effect of processing for improving resolution by subpixel sampling is great. Also, in game content displayed in the game mode, since there are many images that are close to natural images in recent years, the effect of the processing for improving the resolution is also great for images displayed in the game mode. Thus, only in the specific image quality mode, by turning on the processing for improving the resolution by subpixel sampling, it is possible to perform video display with high video quality according to the display video.

  On the other hand, when the image quality mode of the display device is the PC mode or the animation mode, the processing for improving the resolution is turned off. As described above, the PC image is often displayed in accordance with the pixels of the display panel, and the effect of the control in units of subpixels is small. Further, if the video output from the PC uses a lot of general character expressions, the coloring is conspicuous and the effect is reduced. In addition, diagonal lines and the like may be noticeable by the enhancement. As for animations, since there are many images whose outlines are surrounded by black lines, shakiness of diagonal lines due to enhancement may be noticeable. When the processing for improving the resolution is turned off, the processing is switched to pixel sampling.

  As described above, in the embodiment according to the present invention, when the image quality mode set in the display device is any one of the movie mode, the standard mode, the dynamic mode, and the game mode, the processing for improving the resolution is turned on, When the mode is the PC mode or the animation mode, the processing for improving the resolution is turned off. As a result, display data is generated and displayed for each of the sub-pixels so that high-resolution expression is possible. At this time, it is possible to perform video display with optimal video quality according to the characteristics of the video content. become.

In the above example, the processing for improving the resolution by sub-pixel sampling is turned ON / OFF according to the image quality mode, but the processing for changing the strength of the processing for improving the resolution according to the image quality mode is performed. May be.
For example, enhancement processing (edge enhancement processing) is performed on the input video signal, and at this time, enhancement can be performed on a pixel basis and smoothing can be performed on a subpixel basis. The enhancement processing includes a shoot enhancement technique in which a correction signal based on a high frequency component of an input video signal is added to an original signal to add undershoot or overshoot. If undershoot and overshoot are strengthened and smoothing is performed in units of subpixels, a higher sharpness can be obtained. This is the intensity of the processing for improving the resolution, and the intensity is changed according to the image quality mode.

  For example, in the dynamic mode and the movie mode, the above-described strength is increased and the sharpness of enhancement is increased. In the standard mode and the game mode, the above strength is set to a medium level. In the PC mode, the above strength is weakened so that the sharpness of enhancement is not emphasized so much. Also, if there is a photo mode for displaying a photo, the above collaboration is set weakly in this case as well. These strong, medium, and weak strengths indicate relative relationships between modes, and specific smoothing coefficients and the like can be arbitrarily determined as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Display part, 2 ... Input part, 3 ... Image processing circuit, 4 ... Control part, 5 ... Light source control circuit, 6 ... Drive control circuit, 7 ... Color filter, 8 ... Liquid crystal panel main body, 9 ... Backlight light source, DESCRIPTION OF SYMBOLS 11 ... Pixel, 13 ... Data signal line drive circuit, 14 ... Scanning signal line drive circuit, 61 ... Display control circuit, 62 ... Conversion circuit, 101 ... Pixel configuration, 102 ... Pixel configuration, 103 ... Pixel configuration, 104 ... Pixel configuration .

In order to solve the above problems, a first technical means of the present invention is a display device having an image quality mode for displaying an image with an optimum image quality according to the type of input video signal. includes a display panel in which one pixel by the color sub-pixels are configured, and a display control unit that performs processing for generating a video signal to be displayed on the display panel from said input video signal, the display control unit, the Processing to improve the resolution of a display image by sampling the input video signal at subpixel intervals to generate display data based on the input video signal for each of the subpixels, and displaying the display data on the display panel; Sampling is performed at one position for each pixel, and the data sampled for each pixel is transferred to other sub-pixels within the same pixel. The switching between processing for generating display data based on the input image signal in pixels by assigning performed, depending on the setting of the image quality mode, to the display OFF or ON the processing for improving the resolution of the image It is a feature.

The subpixel sampling shown in FIG. 4B does not create subpixel data by interpolating the data sampled in units of subpixels as described above, but actually samples the input video signal at subpixel intervals. Data can be obtained, and data faithful to the input video signal can be obtained. Here, the input video signal is sampled at a sampling frequency fx corresponding to a sub-pixel unit. In this case, the R subpixel is shifted by Δx / 3 from the G subpixel, and the B subpixel is sampled by shifting by −Δx / 3 from the G subpixel, and the pixel value is assigned.

Claims (7)

In a display device having an image quality mode for performing display with an optimum image quality according to the type of input video signal,
The display device includes a display panel in which one pixel is configured by sub-pixels of four colors, and a display control unit that performs processing for generating a video signal to be displayed on the display panel from the input video signal, A display control unit configured to generate display data based on an input video signal for each of the sub-pixels and display the display data on the display panel to improve a resolution of a display image; And a process for generating display data based on the image quality, and the process for improving the resolution of the display image is turned off or on according to the setting of the image quality mode. 2. The display device according to claim 1, wherein the image quality mode includes a movie mode for optimally displaying a movie, a standard mode for displaying an image with a standard image quality, and a clear and vivid image. At least one or more of a dynamic mode and a game mode for optimally displaying game images,
The display control unit turns on the processing for improving the resolution when the image quality mode set in the display device is any one of the movie mode, the standard mode, the dynamic mode, and the game mode. A display device characterized by that. The display device according to claim 1 or 2, wherein the image quality mode includes one or both of a PC mode for optimally displaying an image output from a personal computer and an animation mode for optimally displaying an animation. Have
The display control unit, when the image quality mode set in the display device is the PC mode or the animation mode, turns off the processing for improving the resolution.   4. The display device according to claim 1, wherein the display panel includes two high-luminance subpixels out of the four color subpixels, and the other two low-luminance subpixels. A display device having a luminance at least twice as high as the luminance, wherein the high-luminance sub-pixels are arranged apart from each other in the one pixel.   5. The display device according to claim 4, wherein the high-luminance sub-pixel and other sub-pixels other than the high-luminance sub-pixel are alternately arranged.   6. The display device according to claim 4, wherein an area of each of the high-luminance sub-pixels is smaller than that of the other sub-pixels in the one pixel.   7. The display device according to claim 4, wherein the four-color sub-pixels are red, green, blue, and yellow sub-pixels, and the high-luminance sub-pixels are green and A display device having yellow sub-pixels.

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