JP2007114491A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device having high resolution and satisfactory image quality. <P>SOLUTION: The display device for performing display by pixels corresponding to RGB includes the first pixel corresponding to G and the second pixel corresponding to R or B. The second pixel alternately performs the display corresponding to R and the display corresponding to B. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device that supports color display using RGB.

  A typical example of a color display method in a display device is a method using pixels or subpixels corresponding to RGB. In such color display using RGB, various proposals have been made regarding a method of arranging pixels or subpixels corresponding to R, G, and B (see, for example, Patent Document 1).

  As an example of the above-described pixel arrangement method, there is a so-called stripe arrangement (stripe structure). FIG. 1 is a diagram illustrating an example of pixels arranged in stripes. In the stripe arrangement shown in FIG. 1, three subpixels R, G, and B are collected to constitute one pixel. However, this method complicates the structure and requires a very high cost for high definition. Therefore, a Bayer array (Bayer structure) as shown below is often used as the pixel array of the display device. Yes.

  FIG. 2 is a diagram illustrating an example of pixels arranged in a Bayer array. In the Bayer arrangement shown in FIG. 2, G, which is a main component of a luminance signal that requires high resolution, is arranged in a checkered pattern, and R and B, which are two color components that may have a relatively low resolution, are displayed in the remaining part. It has a structure arranged in a shape. In the Bayer structure, for example, one structure (R, B, or G) becomes one pixel, so that there is an advantage that the structure of the display device becomes simple and the display device can be easily manufactured. Further, although the size of one pixel is relatively larger than that of the stripe structure, it has a feature that high definition is easy.

For example, if the size of one pixel is 1 mm (vertical) × 1 mm (horizontal), one subpixel is 0.33 mm × 1 mm in the case of the stripe arrangement described above. On the other hand, in the case of the Bayer array, the size of one pixel corresponding to the sub-pixel is 0.58 mm × 0.58 mm. For example, when the stripe arrangement and the Bayer arrangement are compared with the same screen size, the Bayer arrangement is three times as compared with the number of pixels, and the Bayer arrangement is advantageous for high definition.
JP 2005-91875 A

  However, in the Bayer array, as described above, since the size of one pixel is relatively larger than that of the stripe array, the pixel structure is easily noticeable, which may cause the image quality of the image to deteriorate. Such a problem of image quality degradation will be described below with reference to the drawings.

  FIG. 3A schematically shows how R, G, and B appear in a stripe arrangement and FIG. 3B in a Bayer arrangement, respectively. For example, when displaying uniform white, the luminance of the subpixels in the stripe arrangement shown in FIG. 3A is R: 0.2126, G: 0.7152, and B: 0.0722. The luminance of the pixel in the case of the Bayer array shown in FIG. 3B is R: 0.2126, both G1 and G2 are: 0.3576, and B: 0.0722.

  The reason why the brightness of G differs between the stripe arrangement and the Bayer arrangement is that the number of G is doubled in the Bayer arrangement. When the above display is actually observed, in the case of the stripe arrangement, the R and B sub-pixels appear to be slightly dark in one pixel, whereas in the case of the Bayer arrangement, the 4-pixel sub-pixel is seen. Among them, there was a problem that only one B looks very dark.

  Such a phenomenon that the sub-pixel or pixel corresponding to B looks darker than other sub-pixels or pixels also occurs in the case of the stripe arrangement, but in the case of the Bayer arrangement, the following reasons As a result, the deterioration of image quality becomes noticeable.

  First, the Bayer array has a feature that the difference in luminance between R and G is smaller than that of a stripe array. For this reason, the decrease in the brightness of B is more emphasized.

  Second, in the Bayer array, one of the four pixels is dark. For this reason, the presence of dark areas becomes rough as compared with the stripe arrangement and the like, and the deterioration of image quality is conspicuous.

  Accordingly, an object of the present invention is to provide a new and useful display device that solves the above-described problems.

  A specific problem of the present invention is to provide a display device having high resolution and good image quality.

  The present invention provides a display device that displays the above-described problem using pixels corresponding to RGB, and includes a first pixel corresponding to G and a second pixel corresponding to R or B. The second pixel is solved by a display device characterized in that a display corresponding to R and a display corresponding to B are alternately performed.

  According to the present invention, it is possible to provide a display device having high resolution and good image quality.

  Further, illumination corresponding to RGB is used for display of the first pixel and the second pixel, and the display of the second pixel includes illumination corresponding to R and illumination corresponding to B. If the display is performed by alternately lighting, it is possible to easily perform the alternate display of R and B of the second pixel.

  Further, if the illumination corresponding to RGB is made of LEDs, the power consumption of the illumination is small, and the structure of the display device becomes simple.

  In addition, a color filter is used to display the first pixel and the second pixel, and the display of the second pixel is a color filter corresponding to R with respect to the display in which R and B are added, When the color filters corresponding to B and B are alternately enabled, it is possible to perform the R and B alternate display of the second pixel with a simple structure.

  According to the present invention, it is possible to provide a display device having high resolution and good image quality.

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

  FIG. 4 is a diagram showing a pixel arrangement (pixel structure) of the display device according to the present invention. Referring to FIG. 4, in the pixel array according to the present invention, in the conventional Bayer array, a pixel corresponding to R and a pixel corresponding to B are replaced with a pixel corresponding to R + B (M, magenta). That is, in the pixel array arranged in a grid pattern, the same number of pixels (pixels G1 and G2) corresponding to the display of G and the same number of pixels (pixels M and M2) corresponding to the display of M are arranged in a checkered pattern. Yes.

  In this case, R and B are displayed alternately instead of displaying R and B at the pixel corresponding to the display of M at the same time. For example, FIGS. 5A and 5B show a first display state (hereinafter, in-text state 1) and a second display state (hereinafter, in-text state 2), respectively, in the above pixel array. In the state 1 shown in FIG. 5A, the pixels G1 and G2 display G, whereas the pixels M1 and M2 display R, which are the pixels R1 and R2. Similarly, in the state 2 shown in FIG. 5B, the pixels G1 and G2 display G, whereas the pixels M1 and M2 display B and are pixels B1 and B2.

  By adopting the above pixel arrangement, the portion where the luminance is extremely dark (the pixel corresponding to the display of B) is a ratio of two pixels to four pixels, and the portion where the luminance is extremely dark is compared with the conventional Bayer arrangement. Since it is dispersed, the image quality is improved. For this reason, it is possible to improve the image quality of the Bayer array, which can easily realize high resolution by high definition, and it is possible to provide a display device having good image quality and resolution.

  In addition, the description of the pixel arrangement is schematic, and the actual number of pixels can be arbitrarily increased. (The same applies hereinafter).

  Next, more specific examples of the present invention described above will be shown below.

  FIG. 6 schematically shows the color filter F used in the display device according to the first embodiment of the present invention. The color filter F has a structure in which a color filter f1 corresponding to G display and a color filter f2 corresponding to M display are arranged in a checkered pattern. The filter f1 is used for a pixel displaying G, and the filter f2 is used for a pixel displaying M (R or B). In the display device described below, a pixel corresponding to G display is configured by the structure under the filter f1 and the color filter f1, and M (R or B) display is performed by the structure under the filter f2 and the color filter f2. A pixel corresponding to is configured.

  FIG. 7 is a diagram schematically showing the outline of the structure of the display device 100 according to the first embodiment of the present invention using the color filter F described above. However, in the figure, the same reference numerals are given to the parts described above, and the description will be omitted.

  Referring to FIG. 7, the display device according to the present embodiment has a structure in which the color filter F is stacked on a liquid crystal layer LC that is configured to be capable of modulating light for each pixel. ing. Further, a backlight layer BL is provided on the opposite side of the liquid crystal layer LC from the side on which the color filter F is provided via a diffusion plate DF. The backlight layer BL is provided with a plurality of illumination means L corresponding to the pixels. The lighting means L of the backlight layer BL are controlled to be turned on (ON) and turned off (OFF) by the control means 101. In addition, the display of the arrangement | sequence of the illumination means L in this figure is typical, and about the arrangement | sequence of the illumination means L, it shows in FIG. 8 next.

  FIG. 8 is a diagram showing an arrangement of a plurality of illumination means L installed on the backlight layer BL. Referring to FIG. 8, the illumination means L includes illumination corresponding to R (indicated by R in the figure), illumination corresponding to G (indicated by G in the figure), and illumination corresponding to B (in the figure). And the illumination means are arranged as shown in the figure.

  In this case, the illumination means corresponding to G is configured so as to correspond to the pixel displaying G, and the illumination corresponding to R and the illumination corresponding to B correspond to the pixel displaying M. That is, the color filter F and the backlight layer BL are laminated so that the illumination means corresponding to G corresponds to the color filter f1, the illumination means corresponding to R, and the illumination means corresponding to B to the filter f2. The

  For example, in the above-described structure, it is preferable to use an LED for the illumination unit because the power consumption of the illumination unit is suppressed and the structure of the display device is simplified.

  FIG. 9 is a diagram showing the timing of control of ON / OFF (lighting / extinguishing) of the lighting means L by the control means 101. R, G, and B at the left end in the figure represent the illumination means corresponding to R, the illumination means corresponding to G, and the illumination means corresponding to B, respectively, and the horizontal axis represents the passage of time.

  Referring to FIG. 9, the illumination means corresponding to G is continuously lit, while the illumination means corresponding to R and the illumination means corresponding to B are alternately lit (turned off alternately). It is controlled so that. That is, when the illumination means corresponding to R is turned on, the illumination means corresponding to B is turned off. Conversely, when the illumination means corresponding to R is turned off, the illumination means corresponding to B is turned off. It is controlled to be lit.

  For this reason, in the display device according to the present embodiment, the display of R and the display of B are alternately performed in the pixel displaying M (corresponding to the color filter f2).

  With the configuration described above, in the display device according to the present embodiment, the number of pixels corresponding to the display of B in which the luminance is extremely dark is 2 pixels per 4 pixels, and the portion in which the luminance is extremely dark is the conventional Bayer. Distributed compared to the array. Therefore, the image quality of the Bayer array display device is improved.

  Note that a conventional method (passive matrix method, active matrix method, or the like) can be used for the light modulation control method (control circuit) of the liquid crystal layer, and is not shown in this embodiment.

  In addition, the display device according to the present invention is not limited to the above structure, and can be variously configured. For example, the present invention can be applied not only to a liquid crystal display device but also to a display device using a light emitting element (for example, an organic EL element).

  FIG. 10 is a diagram schematically illustrating the outline of the structure of the display device 200 according to the second embodiment of the invention. Referring to FIG. 2, the display device 200 has a structure in which a color filter F1 and a color filter F2 are stacked on a light emitting element layer EL. The light emitting element layer EL has a structure in which light emitting elements EL1 corresponding to G display and light emitting elements EL2 corresponding to M display are arranged in a checkered pattern. In the present embodiment, a pixel for displaying G and a pixel for displaying M are configured by the light emitting elements EL1 and EL2 and the stacked filters, respectively. The color filters F1 and F2 have a structure in which the filter characteristics are controlled by the control means 201 and 202, respectively.

  FIG. 11 is a diagram showing characteristics of the color filters F1 and F2 with respect to the control signal. Referring to FIG. 11, for example, when the control signal is turned ON, the color filter F1 has a color filter function and has a characteristic corresponding to R + G. When the control signal is turned off, the control signal becomes transparent and does not have a substantial filter function.

  Similarly, when the control signal is turned on, the color filter F2 has a color filter function and has a characteristic corresponding to B + G. When the control signal is turned off, the control signal becomes transparent and does not have a substantial filter function.

  FIG. 12 is a diagram showing a state of control of the color filters F1 and F2 by the control means 201 and 202. Referring to FIG. 12, in the display device according to the present embodiment, the control unit 201 enables the color filter F1 (output becomes R + G), and the control unit 202 enables the color filter F2. Control (output becomes B + G) is performed alternately.

  That is, when the color filter F1 is valid (R + G), the color filter F2 is invalid (transparent), and when the color filter F1 is invalid (transparent), the color filter F2 Is controlled to be effective (B + G).

  For this reason, in the display device according to the present embodiment, the display of R and the display of B are alternately performed in the pixel displaying M (corresponding to the display element EL2). For example, in state 1 in the figure, a color filter (color filter F1) corresponding to the display of R is effective for the light emitting element EL2, and in state 2, conversely, B is applied to the light emitting element EL2. The color filter (color filter F2) corresponding to the display of is effective.

  With the configuration described above, in the display device according to the present embodiment, the number of pixels corresponding to the display of B in which the luminance is extremely dark is 2 pixels per 4 pixels, and the portion in which the luminance is extremely dark is the conventional Bayer. Distributed compared to the array. Therefore, the image quality of the Bayer array display device is improved.

  Note that a conventional method (passive matrix method, active matrix method, or the like) can be used for the light emission control method (control circuit) of the light emitting element layer EL, and is not shown in this embodiment.

  In the first and second embodiments, the display device using the liquid crystal and the organic EL element has been described. However, the present invention is not limited to this. For example, it is obvious that the present invention can be applied to a display device of PDP, FED, or projection system.

  Although the present invention has been described with reference to the preferred embodiments, the present invention is not limited to the specific embodiments described above, and various modifications and changes can be made within the scope described in the claims.

It is a figure which shows an example of the pixel arranged in stripes. It is a figure which shows an example of the pixel by which Bayer arrangement was carried out. It is the figure which showed typically how R, G, and B of a stripe arrangement look. It is the figure which showed typically how R, G, and B of a Bayer arrangement look. It is a figure which shows the pixel arrangement | sequence (pixel structure) of the display apparatus of this invention. FIG. 5 is a first diagram illustrating a display state of the pixel in FIG. 4. FIG. 5 is a second diagram illustrating a display state of the pixel in FIG. 4. 3 is a color filter used in the display device according to the first embodiment. 1 is a schematic diagram of a display device according to Example 1. FIG. It is an example of the arrangement | sequence of the illumination means of the display apparatus of FIG. It is a figure which shows the timing of ON / OFF control of the illumination means of FIG. 6 is a schematic view of a display device according to Example 2. FIG. It is the figure which showed the characteristic of the color filter of the display apparatus of FIG. It is the figure which showed control of the color filter of FIG.

Explanation of symbols

100, 200 Display device F, F1, F2, f1, f2 Color filter LC Liquid crystal layer DF Diffuser plate BL Backlight layer L Illuminating means 101, 201, 202 Control means EL light emitting element layer EL1, EL2 Light emitting element

Claims (4)

A display device that performs display using pixels corresponding to RGB,
A first pixel corresponding to G;
A second pixel corresponding to R or B,
The display device characterized in that the second pixel alternately performs display corresponding to R and display corresponding to B. Illumination corresponding to RGB is used for displaying the first pixel and the second pixel,
2. The display device according to claim 1, wherein the display of the second pixel is performed by alternately lighting illumination corresponding to R and illumination corresponding to B. 3.   The display device according to claim 2, wherein the illumination corresponding to RGB is made of an LED. A color filter is used to display the first pixel and the second pixel,
The display of the second pixel is performed by alternately enabling a color filter corresponding to R and a color filter corresponding to B with respect to the display in which R and B are added. Item 4. The display device according to Item 1.

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