JP4626478B2 - Image display device, electronic device, and pixel arrangement design method - Google Patents

Description

  The present invention relates to an image display device, an electronic apparatus, and a pixel arrangement design method.

  Conventionally, there has been known an image display apparatus capable of displaying an image using four or more primary colors (hereinafter also referred to as “multi-primary colors”). For example, Patent Document 1 describes an image display apparatus that performs display using four primary colors of Red, Green, Blue, and Cyan (hereinafter also simply referred to as “RGBC”).

JP 2001-306003 A

  However, in the technique described in Patent Document 1 described above, the arrangement of sub-pixels corresponding to RGBC has not been performed in consideration of the effect on vision.

  The present invention has been made in view of the above points. An image display device in which pixels constituting the four primary colors are arranged, an electronic device having the image display device, and a sufficient influence on visual perception, and It is an object of the present invention to provide a pixel arrangement design method for determining the arrangement of pixels.

In one aspect of the present invention, in an image display apparatus that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors, the display pixel includes the four sub-pixels. Of the colors, two sub-pixels having low luminance are arranged at both ends of the display pixel, the luminance of the colors of the two sub-pixels arranged at both ends, and the two sub-pixels arranged at both ends. The remaining two colors excluding the two colors used at both ends of the display pixel are reduced so that the absolute value of the difference between the two luminance addition values obtained from the luminance of the colors of the sub-pixels adjacent to each pixel is reduced. A color sub-pixel is arranged in the center, and each colored region in the colors of the four sub-pixels is a blue-based colored region or a red-based colored region in a visible light region whose hue changes according to a wavelength. Wearing the hue of Regions, and two colored regions of the hue that is selected from among colors ranging from blue to yellow.
In another aspect of the present invention, in an image display device that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors, the display pixel includes the four sub-pixels. Of the colors, two sub-pixels having low luminance are arranged at both ends of the display pixel, the luminance of the colors of the two sub-pixels arranged at both ends, and the two sub-pixels arranged at both ends. The remaining two colors excluding the two colors used at both ends of the display pixel are reduced so that the absolute value of the difference between the two luminance addition values obtained from the luminance of the colors of the sub-pixels adjacent to each pixel is reduced. A colored sub-pixel is arranged in the center, and each colored region in the colors of the four sub-pixels has a colored region in which the peak of the wavelength of light transmitted through the colored region is 415 to 500 nm, and 600 n A colored area in the above, the colored region in the 485-535nm, a colored region in 500～590Nm.
In another aspect of the present invention, in an image display device that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors, the display pixel includes the four sub-pixels. Of the colors, two sub-pixels having low luminance are arranged at both ends of the display pixel, the luminance of the colors of the two sub-pixels arranged at both ends, and the two sub-pixels arranged at both ends. The remaining two colors excluding the two colors used at both ends of the display pixel are reduced so that the absolute value of the difference between the two luminance addition values obtained from the luminance of the colors of the sub-pixels adjacent to each pixel is reduced. A color sub-pixel is arranged in the center, and the display pixel is a display pixel that is vertically adjacent in the vertical direction, and the display pixel of each display pixel is at least one sub-pixel. It is arranged so as to only deviate up and down.
According to the above image display device, it is possible to reduce the luminance error in the display image and to reduce the edge blurring phenomenon when visually observed. Therefore, according to the image display device, it is possible to display a high-quality image.

  In one aspect of the image display device, the luminance and the luminance addition value are values defined in a luminance-opposite color space, and are defined based on visual space characteristics in the luminance-opposite color space. As a result, it is possible to arrange the sub-pixels in consideration of the visual impact.

  In another preferred example of the image display device, the four pixels are configured by Red, Green, Blue, and White, and the display pixel includes the four sub-pixels in the order of Blue, White, Green, and Red. It is arranged with.

  In a preferred example, a plurality of the display pixels are arranged on a straight line so that the same color is continuous in the vertical direction of the image display device. That is, display pixels are arranged in stripes. The vertical direction means a direction orthogonal to the scanning direction.

  In another preferred example, the display pixels are arranged so that the display pixels adjacent to each other in the vertical direction in the vertical direction are shifted vertically by at least one subpixel. ing. Thereby, the number of display pixels in the horizontal direction can be reduced while suppressing deterioration of the display image. Thus, the cost of the image display device can be reduced.

  Preferably, the horizontal width of the sub-pixel is approximately one quarter of the horizontal width of the display pixel. The image display device includes a color filter disposed so as to overlap the sub-pixel.

  Further, the above image display device can be suitably applied to an electronic apparatus including a power supply device that supplies a voltage to the image display device.

In another aspect of the present invention, in an image display device that displays an image using a display pixel having a set of four sub-pixels corresponding to different colors, a pixel arrangement that determines the arrangement of the four sub-pixels The design method includes a first arrangement determining step of determining the positions of two color sub-pixels having low luminance among the four sub-pixels at both ends of the display pixel, and two sub-pixels arranged at both ends. color and intensity of, as the absolute value becomes smaller in the difference of the two luminance addition values obtained from the color of the luminance of the sub-pixels adjacent to each of the two sub-pixels arranged in the both ends, of the display pixels comprising a second arrangement determining step of arranging the remaining two sub-pixels of the color in the center, except for the two colors used on both ends, a. By applying the sub-pixel arrangement determined by the pixel arrangement design method described above to the image display device, the luminance error in the display image is reduced and the edge blurring phenomenon when visually observed is reduced. A display device can be realized.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
A first embodiment of the present invention will be described.

(overall structure)
FIG. 1 is a block diagram illustrating a schematic configuration of an image display apparatus 100 according to the first embodiment. The image display apparatus 100 mainly includes an image processing unit 10, a data line driving circuit 21, a scanning line driving circuit 22, and a display unit 23. The image display device 100 is configured to be able to display an image using multiple primary colors. Specifically, the image display apparatus 100 can display four primary colors of Red, Green, Blue, and Cyan (hereinafter also simply referred to as “R”, “G”, “B”, and “C”). It is configured.

  The image processing unit 10 includes an I / F control circuit 11, a color conversion circuit 12, a VRAM 13, an address control circuit 14, a table storage memory 15, and a γ correction circuit 16. The I / F control circuit 11 acquires image data and a control command from the outside (for example, a camera) and supplies the image data d1 to the color conversion circuit 12. Note that image data supplied from the outside is composed of three primary colors of R, G, and B.

  The color conversion circuit 12 performs processing for converting the acquired image data d1 from three primary colors to four primary colors. In this case, the color conversion circuit 12 performs image processing such as color conversion with reference to data stored in the table storage memory 15. The image data d2 subjected to image processing by the color conversion circuit 12 is written in the VRAM 13. The image data d2 written in the VRAM 13 is read out as image data d3 by the γ correction circuit 16 based on a control signal d21 from the address control circuit, and at the same time, the address data (scanning line driving circuit 22 is read by the scanning line driving circuit 22). Read as d4) (to synchronize based on address data). The γ correction circuit 16 refers to the data stored in the table storage memory 15 and performs γ correction on the acquired image data d3. Then, the γ correction circuit 16 supplies the image data d5 after γ correction to the data line driving circuit 21.

  The data line driving circuit 21 supplies data line driving signals X1 to X2560 to 2560 data lines. The scanning line driving circuit 22 supplies scanning line driving signals Y1 to Y480 to 480 scanning lines. In this case, the data line driving circuit 21 and the scanning line driving circuit 22 drive the display panel 23 in synchronization. The display unit 23 is composed of a liquid crystal (LCD), and displays an image using the four primary colors RGBC. The display unit 23 includes unit pixels (hereinafter referred to as “display pixels”) having four pixels corresponding to RGBC (hereinafter referred to as “sub-pixels”) as a set of “480 vertical ×× vertical pixels”. It is constituted by VGA size having “640 horizontal”. Therefore, the number of data lines is “640 × 4 = 2560”. The display unit 23 displays images such as characters and video to be displayed by applying voltages to the scanning lines and the data lines.

  FIG. 2 is a schematic view showing each pixel of the display unit 23 in an enlarged manner. A white circle 153 indicates the position of the display pixel 151, and a difference in hatching indicates a difference between “R”, “G”, “B”, and “C” constituting the sub-pixel 152. In this case, a plurality of display pixels 151 are arranged on a straight line so that the same color is continuous in the vertical direction, that is, in a stripe arrangement. Further, since the vertical / horizontal length ratio of the display pixel 151 is “1: 1”, regarding the sub-pixel 152, if the vertical length is “1”, the horizontal length is “0. 25 ". In this specification, “vertical direction” means a direction orthogonal to the scanning direction, and “lateral direction” means a direction horizontal to the scanning direction. Details of a specific arrangement of the sub-pixels 152 and a method of determining the arrangement of the sub-pixels 152 will be described later.

  FIG. 3 is a perspective view showing a specific configuration of the display unit 23. As shown in FIG. 3, a pixel electrode 23f is formed inside the TFT array substrate 23g, and a common electrode 23d is formed inside the counter substrate 23b. Further, a color filter 23c is formed between the counter substrate 23b and the common electrode 23d. A backlight unit 23i and upper and lower polarizing plates 23a and 23h are formed outside the TFT array substrate 23g and the counter substrate 23b.

  Specifically, the TFT array substrate 23g and the counter substrate 23b are made of a transparent substrate such as glass or plastic. The pixel electrode 23f and the common electrode 23d are formed of a transparent conductor such as ITO (indium tin oxide). Further, the pixel electrode 23f is connected to a TFT (Thin Film Transistor) provided on the TFT array substrate 23g, and is applied to the liquid crystal layer 23e between the common electrode 23d and the pixel electrode 23f in accordance with switching driving of the TFT. A voltage is applied. The liquid crystal layer 23e includes liquid crystal molecules whose arrangement changes according to the voltage value applied by the common electrode 23d and the pixel electrode 23f.

  In the liquid crystal layer 23e and the upper and lower polarizing plates 23a and 23h, the alignment of the liquid crystal molecules changes according to the voltage value applied to the liquid crystal layer 23e, so that the liquid crystal layer 23e and the upper and lower polarizing plates 23a and 23h are transmitted. The amount of light to change changes. Therefore, the liquid crystal layer 23e controls the amount of light incident from the backlight unit 23i side, and transmits the light to the observer side with a predetermined light transmission amount. The backlight unit 23i includes a light source and a light guide plate. In such a configuration, the light emitted from the light source is uniformly spread inside the light guide plate, and the light source light is emitted in the direction indicated by the arrow in FIG. A light source is comprised from a fluorescent tube, white LED, etc., and a light-guide plate is comprised from resin, such as an acryl. The display unit 23 having such a configuration is a transmissive liquid crystal display device that emits light emitted from the backlight unit 23i in a direction indicated by an arrow and extracts the light from the counter substrate 23b side. That is, liquid crystal display is performed using the light source light of the backlight unit 23i.

  FIG. 4 is a diagram illustrating an example of display characteristics of the display unit 23. FIG. 4A is a diagram illustrating spectral characteristics of the color filter 23c used in the display unit 23, in which the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the transmittance (%). FIG. 4B is a diagram illustrating the light emission characteristics of the backlight unit 23i, which is a light source. The horizontal axis indicates the wavelength (nm), and the vertical axis indicates the relative luminance. FIG. 4C is a diagram in which the transmission characteristics of the color filter 23c are reflected on the light emission characteristics of the backlight unit 23i, that is, the light emission characteristics of the four primary colors. In FIG. 4C as well, the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the relative luminance. Although the transmitted light is controlled by the liquid crystal layer 23e, the transmission characteristics are almost flat, and this is not shown. FIG. 4D shows a diagram in which tristimulus values representing colors are calculated for the emission characteristics of the four primary colors and plotted on the xy chromaticity diagram. The inside of the square in FIG. 4D indicates a color that can be reproduced on the display unit 23, and this square corresponds to the color reproduction region on the display unit 23. The quadrangular vertices correspond to RGBC constituting the primary color.

(Sub pixel error check method)
In the first embodiment, the sub-pixels of the four primary colors RGBC are arranged in a form that fully considers the effect on vision. Here, a description will be given of visual characteristics and the like that should be taken into consideration when arranging the sub-pixels. Specifically, it will be described how the visual characteristics are affected when the arrangement of sub-pixels is different.

  FIG. 5 is a flowchart showing the sub-pixel error checking process. This sub-pixel error confirmation process is a process performed for confirming an error generated by each candidate for the RGBC pixel arrangement order candidates. In an image display device using sub-pixels, each pixel is arranged side by side on a plane and the color is reproduced by a fine color mixture of light emission. However, due to the visual characteristics, edge blurring and color breakup (false color due to the arrangement of each pixel) ) May occur. The “error” to be confirmed in the subpixel error confirmation process shown in FIG. 5 corresponds to such edge blurring or color breakup. The sub-pixel error confirmation process is executed by a computer or the like.

  First, in step S101, XYZ for each color of RGBC is input. XYZ of each color is a value that can be determined from the spectral characteristics of the color filter 23c and the backlight unit 23i, and is obtained by simulation or actual measurement. Then, the process proceeds to step S102. In step S102, XYZ is converted into a luminance-opposite color space and expressed as Lum, R / G, and B / Y components. Then, the process proceeds to step S103.

  In step S103, filter processing corresponding to visual characteristics is performed in the luminance-opposite color space. The details of this filtering process will be described later. Then, the process proceeds to step S104, and error confirmation such as edge blurring or color breakup is performed on the filter processing result.

  FIG. 6 is a diagram illustrating filter characteristics for luminance-opposite color components. FIG. 6 shows a graph of the Lum component on the left, a graph of the R / G component on the center, and a graph of the Y / B component on the right, with the horizontal axis indicating the position in the image and the vertical axis The weight (specifically, the relative value when the Lum component is “1” when the viewing distance is short) is shown. Further, the graph when the viewing distance is short is shown in the upper stage, and the graph when the viewing distance is far is shown in the lower stage. As shown in FIG. 6, the filter characteristics have different amplitude characteristics and spread widths for the respective components of luminance and opposite colors. Further, since the filter characteristic corresponds to the visual characteristic, the characteristic changes depending on the viewing distance. Furthermore, it can be seen that the R / G component has a larger filter amplitude than the B / Y component.

  FIG. 7 shows an example of a result obtained by the sub-pixel error checking process shown in FIG. FIG. 7A shows a spatial pattern used in the sub-pixel error confirmation process. Specifically, the display pixels arranged in the order of RGBC are used, the display pixel indicated by the central reference numeral 160 is turned off (all blocked), and the display pixel groups indicated by reference numerals 161 and 162 located on both sides thereof are defined. Set to the fully lit (totally transmissive) state. That is, a spatial pattern (hereinafter also referred to as “black and white pattern”) in which the central portion is displayed in black and both sides thereof are displayed in white is used. In this specification, when the arrangement order of sub-pixels is expressed as “RGBC”, “R”, “G”, “B”, and “C” are arranged in order from the left or right. Shall be shown.

  7B, 7 </ b> C, and 7 </ b> D, the horizontal axis indicates the image position corresponding to the black and white pattern, and the vertical axis indicates the Lum component, R / G component, and B / Y component, respectively. In FIG. 7B, graphs in an ideal case where spatially complete color mixing is performed without using the sub-pixel plane arrangement are displayed in an overlapping manner. From FIG. 7B, it can be seen that when the sub-pixel is used, the white portion has a color when observed finely, and thus the unevenness of the graph is generated. Further, it can be seen that in the black portion, a luminance increase that causes edge blurring occurs due to the influence of surrounding sub-pixels. Regarding the R / G component and the B / Y component, when no error occurs (ideal case), the graph repeats at a constant period. However, from FIG. 7C and FIG. 7D, both the R / G component and the B / Y component are affected by the surrounding sub-pixels in the black area and the color components increase, causing color breakup. You can see that For example, in the R / G component of FIG. 7C, the peak portion on the right side of the center increases in the positive (red) direction, and if the black and white pattern is observed, the Red pixel is located. . Such a large increase in the positive direction is a result of the filtering process reflecting the visual characteristics, and such a change does not occur unless the filtering process is performed. That is, such a large color component does not originally exist, but color components appear to be generated by visual observation.

  Here, taking the facts shown in FIGS. 5 to 7 into consideration, the sub-pixel error checking process is performed on the arrangement candidates of the respective pixels of the four primary colors RGBC, and the result is considered.

  8A to 8L show arrangement candidates for the four primary colors RGBC. In this case, the number of combinations in RGBC is “4 × 3 × 2 × 1 = 24”, but considering the left-right symmetry, the number of arrangement candidates is 12, which is half of this. That is, for example, “RGBC” is treated as the same as “CBGR”.

  FIG. 9 shows a result when the sub-pixel error check process is performed on the 12 arrangement candidates shown in FIGS. 9A to 9L, the horizontal axis indicates the image position corresponding to the black and white pattern, and the vertical axis indicates the value of the Lum component. A thick line indicates a graph obtained by the sub-pixel error checking process, and a thin line indicates a graph in an ideal case where spatially complete color mixing is performed without using the sub-pixel plane arrangement. From this, it can be seen that the error is relatively small when the arrangement order of “BGRC” shown in FIG. Although the arrangement order error shown in FIG. 9K or the like appears to be small, the luminance Lum is asymmetrically shifted from the center position of the black display pixel, so that the error is larger than the arrangement order shown in FIG. Is big.

  Hereinafter, the cause of such a result will be described. In detail, it demonstrates paying attention to the luminance Lum. The luminance Lum is defined in the luminance-opposite color space, and is defined based on the visual space characteristics in the luminance-opposite color space. Here, attention is paid to the luminance Lum. When the luminance of the sub-pixel located at the edge is high, the luminance at the edge when white is displayed becomes high, resulting in edge blurring as a result of filtering with black. This is because it is considered that the luminance increases, in other words, the error increases. That is, it is considered that the above-described error is reduced by arranging a sub-pixel having a low luminance at the end of the display.

  Further, when the sub-pixels arranged on both sides of the display pixel are determined in this way, attention is paid to the left-right luminance balance in the display pixel. Specifically, two luminance addition values obtained from two subpixels arranged at both ends and subpixels adjacent to the two subpixels arranged at both ends (in this specification, “luminance addition”). “Value” means a value obtained by adding the luminances of two adjacent sub-pixels.) Based on the difference in luminance, the left and right luminance balance is considered. The reason for paying attention to the balance between the left and right luminances is that if the balance between the left and right luminances is lost, a problem that only one edge is blurred may occur. The reason why the luminance addition values of the two subpixels are used instead of the subpixels alone is that the two subpixels are considered to affect the surroundings in a unified form due to the filter characteristics reflecting the visual characteristics. That is, it is considered that the error is reduced by arranging the central two sub-pixels so that the absolute value of the difference between the two luminance addition values obtained from the two left and right sub-pixels becomes small.

  FIG. 10 is a table specifically showing RGBC luminances and luminance addition values. FIG. 10A shows, in order from the left, the Lum component, R / G component, and B / Y component obtained from XYZ for each color of RGBC. In this specification, the luminance is used as a value corresponding to Y, and the saturation is used as a value representing the intensity of the color.

  FIG. 10B shows a value (luminance addition value) obtained by adding the luminances of two colors (first color and second color) selected from RGBC. Further, FIG. 10C shows a case where “BR” (right set) and “GC” (left set) are combined (ie, “BRGC” in the case where “B” and “C” are arranged at both ends. The absolute value of the difference between the two luminance addition values (when arranged in the order of arrangement) is shown above, and when “BG” (right set) and “RC” (left set) are combined (ie, arranged in the order of “BGRC”) The absolute value of the difference between the two luminance addition values in the case) is shown below. The reason why the values obtained when “B” and “C” are arranged at both ends will be described later.

  FIG. 10A shows that the luminance Lum of Blue and Cyan is small. Accordingly, it is considered that the error is reduced when Blue and Cyan are arranged at both ends of the display pixel. Referring to FIG. 9, when Blue and Cyan are arranged at both ends (for example, FIGS. 9 (k) and (l)), when Blue and Cyan are not arranged at both ends (for example, FIG. 9). Compared with (f)), it can be seen that the error is actually small.

  Further, from FIG. 10C, when Blue and Cyan are arranged at both ends, when “BG” (right set) and “RC” (left set) are combined, the absolute value of the difference between the luminance addition values is I understand that it is small. Accordingly, it is considered that the error is reduced by arranging the order of “BGRC” rather than arranging the order of “BRGC”. Here, referring to FIG. 9, when “BG” and “RC” are combined (see FIG. 9L), when “BR” and “GC” are combined (see FIG. 9K). It can be seen that the error is actually small.

  As described above, the result that the error in the arrangement order of “BGRC” (see FIG. 9L) is small is that two sub-pixels with low luminance are arranged at both ends, and two left and right sub-pixels are arranged. This is because the sub-pixels having a small difference between the luminance addition values in the two luminance addition values respectively obtained from the above are arranged in the center two.

  Note that “CRGB” is an arrangement opposite to “BGRC”. That is, the arrangement of “CRGB” is the same as the arrangement of “BGRC”. Therefore, the same result as in FIG. 9L can be obtained with the arrangement of “CRGB”.

(Sub-pixel arrangement method)
Next, a subpixel arrangement method performed in consideration of the above results and considerations will be described. In the first embodiment, two sub-pixels having low luminance are arranged at both ends, obtained from two sub-pixels arranged at both ends, and sub-pixels adjacent to each of the two sub-pixels arranged at both ends. The sub-pixels are arranged in the center two so that the absolute value of the difference between the two luminance addition values is small.

  FIG. 11 is a flowchart showing the sub-pixel arrangement process. This process is executed by the computer reading the program or by reading the program recorded on the recording medium. Further, this process is executed at the stage of designing the image display device 100.

  First, in step S201, RGBC XYZ colors are input. XYZ of each color is a value that can be determined from the spectral characteristics of the color filter 23c and the backlight unit 23i, and is obtained by simulation or actual measurement. Then, the process proceeds to step S202. In step S202, XYZ is converted into a luminance-opposite color space and expressed as Lum, R / G, and B / Y components. Then, the process proceeds to step S203.

  In step S203, the RGBC arrangement is determined based on the luminance Lum obtained in step S202. First, based on the calculated luminance Lum, two sub-pixels having the lowest luminance Lum are arranged at both ends of the display pixel. When the result as shown in FIG. 10 is obtained, “B” and “C” having low luminance Lum are arranged at both ends. Next, two luminance left and right luminance addition values of the edge sub-pixel and the adjacent sub-pixel are obtained, the absolute value of the difference between these luminance addition values is calculated, and then a candidate with a small absolute value is selected. Specifically, a candidate for combining BR and GC and a candidate for combining BG and RC are conceivable. However, when the result shown in FIG. 10 is obtained, the absolute value of the difference between the luminance addition values is small. And a candidate for combining RC is determined. Thereby, the arrangement order of “BGRC” is determined. Note that “BGRC” is the same as “CRGB”. When the above process ends, the process exits the flow.

  As described above, according to the sub-pixel arrangement processing according to the first embodiment, it is possible to determine the arrangement of RGBC sub-pixels with sufficient consideration of visual characteristics. By applying the arrangement of the sub-pixels determined in this way to the image display apparatus 100, it is possible to reduce the luminance error in the display image and reduce the edge blur phenomenon when visually observed. Thereby, the image display apparatus 100 can display a high-quality image.

  In the above description, the example in which the arrangement of the sub-pixels “BGRC” is determined by the sub-pixel arrangement process is described. However, the arrangement order is not always determined by the sub-pixel arrangement process. Since these are the arrangement order determined based on the result shown in FIG. 10, when a result other than that shown in FIG. 10 is obtained for each pixel of RGBC, an arrangement order different from this arrangement order is obtained. It is determined.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the second embodiment, the configuration of multi-primary colors is different from that of the first embodiment. Specifically, the second embodiment is different from the first embodiment in that White (hereinafter also simply referred to as “W” or “Wh”) is used instead of Cyan. That is, the primary color is constituted by RGBW. In the second embodiment, an image display device having the same configuration as that of the above-described image display device 100 is used, and the description thereof is omitted. In addition, in the “White” sub-pixel, a transparent resin layer is arranged instead of a colored layer.

  FIG. 12 is a diagram illustrating an example of display characteristics of the display unit 23 in the second embodiment. FIG. 12A is a diagram illustrating the spectral characteristics of the color filter 23c, in which the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the transmittance (%). Note that the color filter 23c corresponding to White is not used. FIG. 12B is a diagram showing the light emission characteristics of the backlight unit 23i, where the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the relative luminance. FIG. 12C is a diagram showing the emission characteristics of the four primary colors RGBW, where the horizontal axis indicates the wavelength (nm) and the vertical axis indicates the relative luminance. In this case, since the color filter 23c is not provided in the pixel portion corresponding to White, the white spectral characteristics are substantially the same as the spectral characteristics of the backlight unit 23i. FIG. 12D shows a diagram in which tristimulus values representing colors are calculated for the emission characteristics of the four primary colors and plotted on the xy chromaticity diagram. As shown in FIG. 12D, the color reproduction region is not a quadrangle but a triangle. The vertex of this triangle corresponds to RGB, and W is located inside the triangle. Such a color reproduction region is the same as the color reproduction region for the three primary colors, but the transmittance is increased by adding White to the four primary colors. Therefore, the effect of improving the surface brightness of the display unit 23 can be obtained.

  Next, a subpixel error arrangement method according to the second embodiment will be described. Also in the second embodiment, two sub-pixels having low luminance are arranged at both ends, obtained from two sub-pixels arranged at both ends, and sub-pixels adjacent to each of the two sub-pixels arranged at both ends. The sub-pixels are arranged in the center two so that the absolute value of the difference between the two luminance addition values is small.

  FIG. 13 is a flowchart illustrating a sub-pixel arrangement process for RGBW sub-pixels. This process is executed by the computer reading the program or by reading the program recorded on the recording medium. Further, this process is executed at the stage of designing the image display device 100.

  First, in step S301, XYZ for each RGBW color is input. XYZ of each color is a value that can be determined from the spectral characteristics of the color filter 23c and the backlight unit 23i, and is obtained by simulation or actual measurement. Then, the process proceeds to step S302. In step S302, XYZ is converted into a luminance-opposite color space and expressed as Lum, R / G, and B / Y components. Then, the process proceeds to step S303.

  In step S303, the RGBW arrangement is determined based on the luminance Lum obtained in step S202. Specifically, first, the luminance Lum and the luminance addition value in RGBW are obtained. For example, a table as shown in FIG. 14 is obtained.

  FIG. 14 is a table specifically showing RGBW luminances and luminance addition values. FIG. 14A shows, in order from the left, the Lum component, R / G component, and B / Y component obtained from XYZ for each color of RGBW. FIG. 14B shows a value (luminance addition value) obtained by adding the luminances of two colors (first color and second color) selected from RGBW. Further, FIG. 14C shows a case where “BG” (right set) and “WR” (left set) are combined in a case where “B” and “R” are arranged at both ends (that is, “BGWR” The absolute value of the difference between the two luminance addition values (when arranged in the arrangement order) is shown above, and when “BW” (right set) and “GR” (left set) are combined (ie, arranged in the arrangement order of “BWGR”) The absolute value of the difference between the two luminance addition values in the case) is shown below.

  FIG. 14A shows that the luminance Lum of Blue and Red is small. Further, from FIG. 14C, when Blue and Red are arranged at both ends, when “BW” (right set) and “GR” (left set) are combined, the absolute value of the difference between the luminance addition values is I understand that it is small. That is, the absolute value of the difference between the luminance addition values is smaller in the arrangement order of “BGGR” than in the arrangement order of “BGWR”.

  Returning to FIG. 13, the procedure for determining the RGBW arrangement order in step S303 will be described. First, based on the calculated luminance Lum, two sub-pixels having the lowest luminance Lum are arranged at both ends of the display pixel. When the result as shown in FIG. 14 is obtained, “B” and “R” having low luminance Lum are arranged at both ends. Next, two luminance left and right luminance addition values of the edge sub-pixel and the adjacent sub-pixel are obtained, the absolute value of the difference between these luminance addition values is calculated, and then a candidate with a small absolute value is selected. Specifically, a candidate for combining BG and WR and a candidate for combining BW and GR are conceivable. However, when the result shown in FIG. 14 is obtained, the absolute value of the difference in luminance addition values is small. And a candidate for combining GR are determined. Thereby, the arrangement order of “BWGR” is determined. “BWGR” is the same as “RGWB”. When the above process ends, the process exits the flow.

  Here, the result of the above sub-pixel arrangement process is compared with the result when the sub-pixel error check process is performed on the arrangement candidates of the respective pixels of the four primary colors RGBW.

  FIGS. 15A to 15L show arrangement candidates for the four primary colors RGBW. In this case, the number of combinations in RGBW is “4 × 3 × 2 × 1 = 24”, but considering the left-right symmetry, the number of arrangement candidates is 12, which is half of this.

  FIG. 16 shows the results when the sub-pixel error check process is performed on the 12 arrangement candidates shown in FIGS. From this, it can be seen that the error is relatively small when the arrangement order of “RGWB” shown in FIG. Although the arrangement order errors shown in FIGS. 16A and 16F appear to be small, the luminance Lum is asymmetrically shifted from the center position of the black display pixel. The error is larger than the arrangement order shown. From the above, it can be seen that the result of the sub-pixel error confirmation process shows the same result as the sub-pixel arrangement process. That is, two sub-pixels with low luminance are arranged at both ends, and two luminances obtained from two sub-pixels arranged at both ends and sub-pixels adjacent to each of the two sub-pixels arranged at both ends It can be said that the error is reduced by disposing the sub-pixels in the center two so that the absolute value of the difference in the added value is reduced.

  As described above, according to the sub-pixel arrangement processing according to the second embodiment, it is possible to determine the arrangement of RGBW sub-pixels with sufficient consideration of visual characteristics. By applying the arrangement of the sub-pixels determined in this way to the image display apparatus 100, it is possible to reduce the luminance error in the display image and reduce the edge blur phenomenon when visually observed. Thereby, the image display apparatus 100 can display a high-quality image.

  In the above description, an example is shown in which the arrangement of sub-pixels “BWGR” is determined by the sub-pixel arrangement processing, but this arrangement order is not always determined by the sub-pixel arrangement processing. Since these are the arrangement orders determined based on the results shown in FIG. 14, when results other than those shown in FIG. 14 are obtained for each RGBW pixel, an arrangement order different from this arrangement order is obtained. It is determined.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the first and second embodiments described above, the arrangement of display pixels in the display unit 23 is a stripe arrangement, whereas in the third embodiment, the arrangement of display pixels in the display unit (hereinafter referred to as “display”). Also referred to as “pixel arrangement”) from the stripe arrangement.

  FIG. 17 is a block diagram illustrating a schematic configuration of the image display apparatus 101 according to the third embodiment. The image display device 101 is different from the image display device 100 according to the first embodiment (see FIG. 1) in that a resample circuit 11a for an input signal is added and the number of outputs of the data line driving circuit 21 is different. Is the difference. Therefore, the same components and signals are denoted by the same reference numerals and description thereof is omitted.

  The resample circuit 11a changes the number in the horizontal direction in order to match the arrangement of display pixels in the display unit 23z. For example, the resampling circuit 11a performs the above-described change by converting the input digital signal into an analog signal by a D / A converter and then performing re-sampling on the time axis. In another example, the resampling circuit 11a performs the above change by resizing the digital signal.

  The data line driving circuit 21 supplies data line driving signals X1 to X1280 to 1280 data lines. The number of outputs of the data line driving circuit 21 will be described with reference to FIG.

  Here, before explaining the pixel arrangement in the third embodiment, a case where the display pixel arrangement is changed from the stripe arrangement when the three primary colors are used will be described as an example.

  FIG. 18 is a diagram for explaining an example of changing the display pixel arrangement in the three primary colors RGB. In FIG. 18A, a black dot-like grid-like point 180 corresponds to a point where input data exists. For example, in the case of the VGA size, this point 180 is “480 vertical x 640 horizontal”. Further, the arrows in FIG. 18A indicate the input of the data line driving signal and the scanning line driving signal, and the white circle point 181 is a point where data after the change exists (hereinafter also referred to as “sample point”). Is shown.

  The resample circuit 11a described above changes the number in the horizontal direction to match the display pixel arrangement of the display unit 23z. In this case, the interval A11 between the points 181 (in other words, the horizontal length of the display pixel) is doubled, and the number of display pixels is changed to half. Specifically, when the vertical length A12 of the display pixel is “1.0”, the horizontal length A11 of the display pixel is “A11 = A12 × 2 = 2.0”. Each time one horizontal line is lowered in the vertical direction, the sample point is shifted by a half pitch (A11 / 2). By shifting the sample points by a half pitch in this way, even if the number in the horizontal direction is reduced, image display can be performed with relatively little deterioration.

  Next, the display pixel arrangement in the three primary colors will be specifically described with reference to FIG. In this case, the display pixel is formed of a set of three sub-pixels, and the horizontal interval A11 is “2.0”. Therefore, the horizontal length of the sub-pixel is “B11 = A11 / 3 = 0.667. (See the right figure of FIG. 18B). Further, from the left of FIG. 18B, since the display pixel is shifted by a half pitch (A11 / 2) when viewed in the vertical direction, the same sub-pixel is shifted by “A11 / 2”. Further, when viewed as a sub-pixel unit, the shift is “B11 / 2”. In the display unit 23z using the three primary colors, when a set of three colors is observed across two lines, the three colors are arranged at the vertex positions of the inverted triangle, so that a delta arrangement is formed as indicated by reference numeral 185. Has been. The output of the resample circuit 11a is received by a data control circuit (not shown), and the data line driving circuit 21 and the scanning line driving circuit 22 are appropriately controlled by adjusting the timing of the data lines and the scanning lines, thereby displaying an image. The apparatus 101 can appropriately display such a display pixel arrangement.

  Here, the display pixel arrangement according to the third embodiment will be specifically described with reference to FIGS. 19 to 21.

  FIG. 19 is a diagram for explaining the display pixel arrangement according to the first example of the third embodiment. As shown in FIG. 19A, the resample conditions are the same as those in FIG. That is, when the vertical length A12 of the display pixel is “1.0”, the horizontal length A21 of the display pixel is “A21 = A12 × 2 = 2.0”. In this case, since the input and output of the resample circuit 11a are three primary color signals and the display unit 23z has four primary colors, the color conversion circuit 12 performs color conversion from three colors to four colors. FIG. 19B shows a display pixel arrangement. From the right diagram in FIG. 19B, the horizontal length B21 of the sub-pixel is “B21 = A21 / 4 = 0.5”. Further, from the left side of FIG. 19B, since the display pixel is shifted by a half pitch (A21 / 2) when viewed in the vertical direction, the same sub-pixel is shifted by “A21 / 2”. On the other hand, in terms of sub-pixel units, unlike the case of three primary colors (see FIG. 18), the same position is obtained even if one line is lowered. In other words, a boundary between two subpixels in another line is not located between subpixels in one line.

  In the display unit 23z having the display pixel arrangement shown in FIG. 19, when the input data is VGA, the number of display pixels after resampling is “480 vertical × 320 horizontal”. In this case, the number of horizontal sub-pixels is “320 × 4 = 1280”. FIG. 17 described above shows the image display device 101 to which the display unit 23z having the display pixel arrangement shown in FIG. 19 is applied. Therefore, the data line driving circuit 21 supplies data line driving signals X1 to X1280 to 1280 data lines. On the other hand, in the image display device 100 having the stripe arrangement (see FIG. 1), the output from the data line driving circuit 21 to the display unit 23z is “640 × 4 = 2560”. As described above, by applying the display pixel arrangement according to the first example, it is possible to reduce the output from the data line driving circuit 21 even with the same input, so that the cost of the image display device 101 can be reduced. It becomes possible.

  FIG. 20 is a diagram for explaining a display pixel arrangement according to a second example of the third embodiment. As shown in FIG. 20A, when the vertical length A12 of the display pixel is “1.0”, the horizontal length A31 of the display pixel is “A31 = A12 × 1.5 = 1.5”. is there. FIG. 20B shows a display pixel arrangement. In this case, the horizontal length B31 of the sub-pixel is “B31 = A31 / 4 = 0.375”. Further, when viewed in the vertical direction, the display pixels are shifted by a half pitch (A31 / 2), so the same sub-pixels are shifted by “A31 / 2”. On the other hand, when viewed as a sub-pixel unit, the same position is obtained even if one line is lowered. Even when the display pixel arrangement according to the second example is applied, it is possible to reduce the output from the data line driving circuit 21 even with the same input, so that the cost of the image display device 101 can be reduced. Become.

  FIG. 21 is a diagram for explaining a display pixel arrangement according to a third example of the third embodiment. As shown in FIG. 21A, when the vertical length A12 of the display pixel is “1.0”, the horizontal length A41 of the display pixel is “A41 = A12 × 1 = 1.0”. FIG. 20B shows a display pixel arrangement. In this case, the horizontal length B41 of the sub-pixel is “B41 = A41 / 4 = 0.25”. Further, when viewed in the vertical direction, the display pixels are shifted by a half pitch (A41 / 2), so the same subpixels are shifted by “A41 / 2”. On the other hand, when viewed as a sub-pixel unit, the same position is obtained even if one line is lowered. When the display pixel arrangement according to the third example is applied, the number of outputs from the data line driving circuit 21 is not reduced as compared with the case where the stripe arrangement is adopted (see FIG. 2), but the display pixels are half-finished. By shifting the pitch, the lateral resolution is apparently improved.

  In addition, when the display pixel arrangement according to the first to third examples is performed, the arrangement of the sub-pixels constituting the display pixel is the same as the sub-pixel arrangement process and the second example according to the first embodiment described above. The sub pixel arrangement order determined by any of the sub pixel arrangement processes according to the embodiment can be applied. That is, even when the display pixels are arranged with a half-pitch shift, the arrangement order of the RGBC and RGBW sub-pixels can be determined with sufficient consideration of visual characteristics. Specifically, when the four primary colors of RGBC are used, the arrangement order determined by the sub-pixel arrangement processing according to the first embodiment is applied, and when the four primary colors of RGBW are used, the second embodiment is applied. The arrangement determined by the sub-pixel arrangement process is applied.

  As described above, the reason why the sub-pixel arrangement processing according to the first embodiment and the sub-pixel arrangement processing according to the second embodiment can be applied is as follows. The image display apparatus 101 according to the third embodiment includes the resample circuit 11a. However, since the input and output of the resample circuit 11a are three primary colors, the direct influence on the four primary colors is small. Therefore, for example, when displaying a black-and-white pattern as four primary colors, the image display device 101 is in exactly the same state as the operation of the image display device 100 according to the first and second embodiments. On the other hand, in the third embodiment, since the horizontal length in units of sub-pixels is different, the filter characteristics reflecting the visual characteristics are slightly different, but the magnitude relationship of the errors is considered to be preserved almost as it is. As described above, the subpixel arrangement order determined by the subpixel arrangement processing according to the first and second embodiments can also be applied to the case where the display pixel arrangement according to the third embodiment is performed.

  As described above, according to the third embodiment, even when the display pixels are arranged with a half-pitch shift, the color component error in the display image can be reduced and the color breakup phenomenon when visually observed is reduced. be able to. In addition, such a color break-up phenomenon can be reduced for an image display device whose cost is reduced and an image display device whose resolution is apparently improved.

  In the above description, the display pixel arrangement is changed by setting the horizontal length of the display pixels (display pixel interval) to “A21 = 2.0”, “A31 = 1.5”, and “A41 = 1.0”. Although an example has been shown, the present invention can also be applied to the case where the display pixel arrangement is changed by setting the display pixel to a length other than these.

[Modification]
The present invention can also be applied to the case where a configuration other than RGBC and RGBW is used as the four primary colors. For example, the present invention can also be applied when Yellow is used instead of Cyan and White. Moreover, although the white LED backlight which combined fluorescent substance with Blue LED was shown above, this invention is applicable also when a backlight has another structure. For example, the present invention can be applied to RGB three-color LED backlights.

  Further, the present invention is not limited to application to an image display device using a liquid crystal (LCD), but an organic EL display device (OLED), a plasma display device (PDP), a cathode ray tube display device (CRT), a field emission display device. The present invention can be applied to an image display device that performs flat display such as (FED). The present invention can be applied not only to a transmissive liquid crystal display device but also to a reflective or transflective image display device.

  Furthermore, in the above description, R, G, B, C, and the like have been described as specific examples of the plurality of colors used by the image display apparatus that displays an image. In addition to Y (yellow), C (cyan), and M (magenta), colors between R, G, B and Y, C, M, for example, colors such as yellow green and dark green are also included.

[Electronics]
Next, an example of an electronic apparatus to which the image display devices 100 and 101 of the present invention are applied will be described. FIG. 22 is a schematic configuration diagram showing an overall configuration of an electronic apparatus to which the present invention is applied. The electronic apparatus shown here includes a liquid crystal display device 700 as an image display unit, and a control unit 410 that controls the liquid crystal display device 700. The image display devices 100 and 101 of the present invention can be provided in the liquid crystal display device 700. Here, the liquid crystal display device 700 is conceptually divided into a panel structure 403 and a drive circuit 402 formed of a semiconductor IC or the like. The control unit 410 includes a display information output source 411, a display information processing circuit 412, a power supply circuit (power supply device) 413, and a timing generator 414.

  The display information output source 411 includes a memory such as a ROM (Read Only Memory) or a RAM (Random Access Memory), a storage unit such as a magnetic recording disk or an optical recording disk, and a tuning circuit that tunes and outputs a digital image signal. The display information is supplied to the display information processing circuit 412 in the form of an image signal of a predetermined format based on various clock signals generated by the timing generator 414.

  The display information processing circuit 412 includes various well-known circuits such as a serial-parallel conversion circuit, an amplification / inversion circuit, a rotation circuit, a gamma correction circuit, and a clamp circuit, and executes processing of input display information to obtain image information. Are supplied to the drive circuit 402 together with the clock signal CLK. The driving circuit 402 includes a scanning line driving circuit, a data line driving circuit, and an inspection circuit. The power supply circuit 413 supplies a predetermined voltage to each of the above-described components.

  Next, specific examples of electronic devices to which the present invention is applied will be described with reference to FIG.

  First, an example in which the image display apparatuses 100 and 101 according to the present invention are applied to a portable personal computer (so-called notebook personal computer) will be described. FIG. 23A is a perspective view showing the configuration of this personal computer. As shown in the figure, a personal computer 710 includes a main body 712 having a keyboard 711 and a display 713 to which the image display devices 100 and 101 according to the present invention are applied.

  Next, an example in which the image display devices 100 and 101 according to the present invention are applied to a mobile phone will be described. FIG. 23B is a perspective view showing the configuration of this mobile phone. As shown in the figure, the mobile phone 720 includes a plurality of operation buttons 721, a mouthpiece 722, a mouthpiece 723, and a display unit 724 using a liquid crystal display device.

  Other electronic devices to which the image display devices 100 and 101 according to the present invention can be applied include a liquid crystal television and a videophone.

[Other Examples]
In the above description, RGBC has been described as a plurality of colors (colored areas). However, the application of the present invention is not limited to this, and one display pixel may be configured by other four colored areas. it can.

  In this case, the four-color colored region is a blue-colored colored region (also referred to as a “first colored region”) or a red-based color in a visible light region (380 to 780 nm) whose hue changes according to the wavelength. Colored areas (also referred to as “second colored areas”) and two colored areas selected from hues from blue to yellow (“third colored areas”, “fourth colored areas”) "). Here, the term “system” is used. For example, if it is a blue system, the color is not limited to a pure blue hue, and includes a blue-violet color, a blue-green color, and the like. If it is a red hue, it is not limited to red but includes orange. These colored regions may be composed of a single colored layer, or may be composed of a plurality of colored layers having different hues. In addition, although these colored regions are described in terms of hue, the hue can be set by changing the saturation and lightness as appropriate.

The specific hue range is
-The colored region of the blue hue is from violet to blue-green, more preferably from indigo to blue.
-The colored region of red hue is from orange to red.
-One coloring area | region selected by the hue from blue to yellow is blue to green, More preferably, it is blue green to green.
-The other coloring area | region selected by the hue from blue to yellow is green to orange, More preferably, it is green to yellow. Or it is green to yellowish green.

  Here, the same hue is not used for each colored region. For example, when a green hue is used in two colored regions selected from hues of blue to yellow, the other uses a blue or yellowish green hue for one green.

  Thereby, a wider range of color reproducibility than the conventional RGB colored region can be realized.

In the above description, a wide range of color reproducibility by the colored areas of four colors is described in terms of hue, but the following is expressed in terms of the wavelength of light transmitted through the colored areas.
The blue colored region is a colored region having a peak of the wavelength of light transmitted through the region at 415 to 500 nm, and preferably a colored region at 435 to 485 nm.
The red colored region is a colored region having a wavelength peak of light transmitted through the region of 600 nm or more, and preferably a colored region of 605 nm or more.
One colored region selected with a hue from blue to yellow is a colored region having a wavelength peak of light transmitted through the region of 485 to 535 nm, and preferably a colored region of 495 to 520 nm.
-The other colored region selected with a hue from blue to yellow is a colored region having a wavelength peak of light transmitted through the region of 500 to 590 nm, preferably a colored region of 510 to 585 nm, or 530 to 565 nm. This is a colored region.

Further, when the four colored regions are expressed by an x, y chromaticity diagram, the following is obtained.
The blue colored region is a colored region where x ≦ 0.151 and y ≦ 0.056, and preferably a colored region where 0.134 ≦ x ≦ 0.151 and 0.034 ≦ y ≦ 0.056.
The red colored region is a colored region satisfying 0.643 ≦ x and y ≦ 0.333, and preferably a colored region satisfying 0.643 ≦ x ≦ 0.690 and 0.299 ≦ y ≦ 0.333.
-One colored region selected by hue from blue to yellow is a colored region where x ≦ 0.164 and 0.453 ≦ y, preferably a colored region where 0.098 ≦ x ≦ 0.164 and 0.453 ≦ y ≦ 0.759 is there.
The other colored region selected with a hue from blue to yellow is a colored region in the range of 0.257 ≦ x, 0.606 ≦ y, preferably a colored region in the range of 0.257 ≦ x ≦ 0.357, 0.606 ≦ y ≦ 0.670 is there.

  These four colored areas can be applied within the above-described range when the sub-pixel includes a transmission area and a reflection area.

  Note that when the four colored regions in this example are used, an LED, a fluorescent tube, an organic EL, or the like may be used as the RGB light source for the backlight. Alternatively, a white light source may be used. The white light source may be a white light source generated by a blue light emitter and a YAG phosphor.

However, the following are preferable as the RGB light source.
-B has a wavelength peak between 435 nm and 485 nm.-G has a wavelength peak between 520 nm and 545 nm.-R has a wavelength peak between 610 nm and 650 nm. If selected appropriately, a wider range of color reproducibility can be obtained. Moreover, you may use the light source which has a some peak so that a wavelength may come to a peak at 450 nm and 565 nm, for example.

Specific examples of the configuration of the above four colored regions include the following.
・ Colored areas of red, blue, green, cyan (blue green) ・ Colored areas of red, blue, green, and yellow ・ Colored areas of red, blue, dark green, and yellow ・ Hue Red, blue, emerald, yellow colored areas / hues are red, blue, dark green, yellow green colored areas / hues are red, blue green, dark green, yellow green colored areas

1 is a block diagram illustrating a schematic configuration of an image display device according to a first embodiment. It is the schematic which expanded and showed each pixel of the display part. It is a figure which shows the specific structure of a display part. It is the figure which showed an example of the display characteristic of a display part. It is a flowchart which shows the sub pixel error confirmation process which concerns on 1st Embodiment. It is a figure showing the filter characteristic with respect to a luminance-opposite color component. It is a figure which shows an example of the result obtained by the sub pixel error confirmation process. It is the figure which showed the arrangement | positioning candidate of 4 primary colors RGBC. It is a figure which shows the result when a sub pixel error confirmation process is performed with respect to 12 arrangement | positioning candidates of FIG. It is the figure which showed the brightness | luminance and brightness | luminance addition value of RGBC concretely. It is a flowchart which shows a subpixel arrangement | positioning process. It is the figure which showed an example of the display characteristic of the display part in 2nd Embodiment. It is a flowchart which shows the sub pixel arrangement | positioning process which concerns on 2nd Embodiment. It is the figure which showed the brightness | luminance and brightness | luminance addition value of RGBW concretely. It is the figure which showed the arrangement | positioning candidate of 4 primary colors RGBW. FIG. 16 is a diagram illustrating a result when a sub-pixel error check process is performed on the 12 arrangement candidates in FIG. 15. It is a block diagram which shows schematic structure of the image display apparatus which concerns on 3rd Embodiment. It is a figure for demonstrating the example which changes display pixel arrangement | positioning in three primary colors RGB. It is a figure for demonstrating the display pixel arrangement | positioning which concerns on the 1st example of 3rd Embodiment. It is a figure for demonstrating the display pixel arrangement | positioning which concerns on the 2nd example of 3rd Embodiment. It is a figure for demonstrating the display pixel arrangement | positioning which concerns on the 3rd example of 3rd Embodiment. It is a schematic block diagram which shows the whole structure of the electronic device to which this invention is applied. It is a figure which shows the specific example of the electronic device to which this invention is applied.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Image processing part, 12 color conversion circuit, 15 Table storage memory, 16 gamma correction circuit, 21 Data line drive circuit, 22 Scan line drive circuit, 23 Display part, 100, 101 Image display apparatus

Claims (12)

An image display device that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors,
The display pixel is
Among the colors of the four sub-pixels, sub-pixels of two colors having low luminance are arranged at both ends of the display pixel,
Absolute difference in difference between two luminance addition values obtained from the luminance of the colors of the two sub-pixels arranged at both ends and the luminance of the color of the sub-pixel adjacent to each of the two sub-pixels arranged at both ends The subpixels of the remaining two colors excluding the two colors used at both ends of the display pixel are arranged in the center so that the value becomes smaller,
Each of the colored areas in the colors of the four sub-pixels includes a blue hue colored area, a red hue colored area, and a blue to yellow color in a visible light area whose hue changes according to a wavelength. An image display device, which is a colored region of two kinds of hues selected from hues. An image display device that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors,
The display pixel is
Among the colors of the four sub-pixels, sub-pixels of two colors having low luminance are arranged at both ends of the display pixel,
Absolute difference in the difference between two luminance addition values obtained from the luminance of the color of the two subpixels arranged at both ends and the luminance of the color of the subpixel adjacent to each of the two subpixels arranged at both ends The subpixels of the remaining two colors excluding the two colors used at both ends of the display pixel are arranged in the center so that the value becomes small,
Each of the colored regions in the colors of the four sub-pixels includes a colored region having a wavelength peak of 415 to 500 nm, a colored region having a wavelength of 600 nm or more, and a colored region having a wavelength of 485 to 535 nm. And an image display device characterized by being a colored region at 500 to 590 nm. An image display device that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors,
The display pixel is
Among the colors of the four sub-pixels, sub-pixels of two colors having low luminance are arranged at both ends of the display pixel,
Absolute difference in difference between two luminance addition values obtained from the luminance of the colors of the two sub-pixels arranged at both ends and the luminance of the color of the sub-pixel adjacent to each of the two sub-pixels arranged at both ends The subpixels of the remaining two colors excluding the two colors used at both ends of the display pixel are arranged in the center so that the value becomes smaller,
The display pixels are arranged such that, in the display pixels adjacent vertically in the vertical direction, the sub-pixels of the respective display pixels are arranged so as to be shifted vertically by at least one sub-pixel. Display device. The luminance and the luminance addition value, the luminance - the image display device according to any one of claims 1 to 3, characterized in that a value defined in the opponent color space. The image display apparatus according to claim 4 , wherein the luminance and the luminance addition value are defined based on a visual space characteristic in the luminance-opposite color space. The four sub-pixels are composed of Red, Green, Blue, and White.
6. The image display device according to claim 3 , wherein the display pixel includes the four sub-pixels arranged in the order of Blue, White, Green, and Red. Wherein the display pixels, the image display apparatus according to have a plurality of arranged on a straight line so that the same color is continuous in the longitudinal direction in claim 1 or 2, characterized in in the image display device. The display pixels are arranged such that the display pixels adjacent to each other in the vertical direction in the vertical direction are arranged such that the sub-pixels of the display pixels are shifted up and down by at least one sub-pixel. Item 3. The image display device according to Item 1 or 2 . The width of the sub-pixels, the image display apparatus according to any one of claims 1 to 8, characterized in that it is approximately one quarter of the horizontal width of the display pixel. The image display apparatus according to any one of claims 1 to 9, characterized in that it comprises the arranged color filter so as to overlap with the sub-pixel. An image display device according to any one of claims 1 to 10 ,
An electronic apparatus comprising: a power supply device that supplies a voltage to the image display device. In an image display device that displays an image using display pixels each having a set of four sub-pixels corresponding to different colors, a pixel arrangement design method for determining the arrangement of the four sub-pixels,
A first arrangement determining step of determining positions of two sub-pixels of low color among the four sub-pixels at both ends of the display pixel;
Absolute difference in difference between two luminance addition values obtained from the luminance of the colors of the two sub-pixels arranged at both ends and the luminance of the color of the sub-pixel adjacent to each of the two sub-pixels arranged at both ends A second arrangement determining step for arranging the sub-pixels of the remaining two colors excluding the two colors used at both ends of the display pixel in the center so that the value is reduced. Design method.

Images