JPS59100485A - Color image display - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] TECHNICAL FIELD The present invention relates to a pentagonal color image display device, and particularly to a pentagonal color image display device.

The present invention relates to a color image display device in which the pixel arrangement pitch is optimized when a plurality of color elements, for example, the three primary colors of R', +, G'+B, are arranged in a dotted manner.

In conventional picture element arrangement, efforts have been made to make the picture element spacing as small as possible within the technically possible range so that the picture elements cannot be seen. That is, color display devices, color panels, etc. have been manufactured based on the design concept that the smaller the pixel spacing, the better.

However, it is technically difficult to make the pixel spacing extremely small (
Not only is this difficult, but it is also due to the nature of vision.

It has been found that reducing the distance between picture elements does not result in better image quality.

In view of the above-mentioned points, an object of the present invention is to determine the optimal pixel arrangement and pixel spacing based on visual characteristics, thereby improving the image quality of a color panel and facilitating the implementation of the sM technology. We provide all the color □image □surface system □equipment. - In order to achieve such an object, the present invention provides a color image table in which the luminescence amount of a plurality of color elements can be set so that a unit picture element consisting of the first color element with respect to a reference input model number maintains white balance. The thread device is arranged so that the unit pixel spacing is 2-pd, cpd both vertically and horizontally at the optimum viewing distance.

The present invention will be described in detail below with reference to one drawing.

The first drawing shows an arrangement of picture elements used in one embodiment of the present invention. Here, the luminance ratio of multiple color elements in front of each picture element is R-!
:G, 3B, □. Various arrangements of dot-like picture elements can be considered, but it is possible to fill in the gaps on the screen using R (red), G (green), and B (blue) picture elements.

This is because it is isotropic in both the vertical and horizontal directions, and for images with a scanning line structure like television, there are no irregularities along the scanning line and the edges of the picture elements are in a straight line. As shown in the figure, two G picture elements are used for each element. By using G picture elements,
When reproducing white, the luminance per unit area of □ 6 ↓ and R are almost equal. This (komontsu, tejl T S
White color in G system) Kuran “xc”: +R+., B
Pickling ratio: 0.3: 0. ．． 4. ? : 0. // l
): Satisfied. In addition, the fact that there are twice as many G pixels as there are R and B pixels means that the resolution of achromatic and green images is higher than that of images obtained using seven G pixels. It has the advantage of being better (Iruma's eyes are most sensitive to green).

Now, when the panel shown in Figure 1 (4) becomes achromatic, a part of the 5 screen is taken out and its luminance distribution is shown.
Figure (B>'o. In other words, the brightness of only the part corresponding to picture element B becomes i (i.e., it becomes darker)
appear.

FIG. 2 shows the spatial frequency characteristics of vision. Here, the horizontal axis represents the spatial frequency (Cpd), and the vertical axis represents the relative sensitivity (c
lb). As is clear from this figure, the spatial frequency characteristics for the luminance pattern are much broader than those for the five chromaticity pattern. Therefore, while the 5 pixels are coarse, the R-G-B pixel arrangement shown in Figure 1 (A) can be seen as is and colors do not mix, but as the pixels become finer and exceed the chromaticity resolution, colors will mix. . However, changes in brightness, ie, the brightness distribution of picture elements (see FIG. 1 [F])) can be discerned. Furthermore, when the picture elements become finer and exceed the resolution of brightness changes, the arrangement of picture elements according to brightness (see Figure 7, 03) also becomes difficult to see, and the picture elements become indiscernible.

The present applicant has already filed an application for a pixel array with a knitted structure as shown in FIG. It is clear that there is a gap. Such a visual effect is also valid for the dot-like array in the dark area (see FIG. 1(B)). For example, when the spatial size of the picture elements and their arrangement interval are gradually reduced, the interference window (the degree to which the picture element stands) and the sharpness window of only the picture elements become as shown in Figure 1. It appears as a visual effect. As is clear from Fig.
If the picture elements are coarse, as shown by the caustic line, the image quality evaluation value will be small when an image is composed of picture elements where the interference window tends to be too close. On the other hand, when the picture elements become smaller and smaller, it becomes difficult to see (
Based on the visual spatial frequency characteristics shown in Figure 1), the evaluation value when an image is composed of such picture elements (Saitoto Garu).

In addition, the sharpness window of a picture element is relatively large and constant when the picture element is coarse, but as the picture element becomes smaller and the interval between them becomes smaller, the picture element itself becomes sharp. The original sharpness of the window also deteriorates, and the evaluation of the image quality when an image is composed of picture elements that differ from each other also deteriorates.

Based on these facts, it is estimated that there is an optimal value for the pixel spacing. In other words, it can be said that a picture element that is not large, such as the obstructing windows 75S and 41, but is fine enough to leave a sharp window, is optimal.

[Reality] The content of the image itself should determine the evaluation of the original image quality, but when the pixels on one surface with a pixel structure become finer, human vision becomes less sharp than the content of one image. Both the window and the sharpness of the picture element cannot be obtained.

In fact, when a certain type of image (for example, a girl's image) is subjectively evaluated for the sense of interference and sharpness, the characteristics (experimental values) shown in FIG. 5 are obtained. Here, the horizontal axis is the spatial frequency (c
pd), and the vertical axis shows the evaluation value. Further, the solid line indicates the evaluation value of the image quality, and the dotted line and the dashed-dotted line indicate the sense of interference and the sharpness of the image (including the sharpness of the picture elements), respectively. It is clear from this figure that in areas where the picture elements are fine (that is, the spatial frequency is high), the evaluation values indicating the sense of interference and the sense of sharpness have opposite characteristics. As a result, the evaluation value of image quality, which is a comprehensive evaluation, becomes a solid line that is almost at the end of low values for interference and sharpness.

FIG. 6 shows overall image quality evaluation values for other images. Here, the horizontal and vertical axes are number ! As in the figure, the spatial frequency (OPD) and evaluation value are shown, respectively. As clearly seen from this figure, the spatial frequency is 23-11. ! tcp
Around d (at this point, the image quality evaluation value is the highest).

Also, the scanning lines used in current broadcasting! 2! The effective number of scanning lines in this method is about 60. 'The size of the RGGB basic unit of the panel structure shown in Figure 1 ■ is x
If l<=> and the height is ′y (seagull), then the screen height is ≠
The width of one tby (deaf) screen is 10'y (mm). If this screen is converted to 1 point of suitable viewing distance for the Yu-Omoto method, it is 5 times the height of the screen, which is 1, and the value is 23.
ooy-', becomes oy at 27. In the vertical direction, it is equivalent to one scanning line width/unit pixel, etc., and when we calculate the spatial frequency, it is the reciprocal of each, and becomes da 0 - 'Ig cpd.Furthermore, the above-mentioned X is Assuming that 7 units of pixels are arranged horizontally (rectangular), ucpd is calculated as the optimum pitch for J. At this time, y is set to 2fi. The minimum x1■ is X1÷
The reciprocal of 17600 In the tar θ area, horizontal/2:?'Ortm, its optimal pitch is vertical, 2III1+horizontal is 2 to 3.
becomes. In addition, in the //, 2j method, which is a high-precision lfa method, the number of effective scanning lines is 7000, the vertical pitch of picture elements is /, and the aspect ratio is 3X! given that.

Similarly, the drawing is 1000 lines vertically, @1b7o■, and its optimal pitch is vertical/an (, a, y-cpd)
.

To the horizontal, it becomes l stiff ~ 2.7 sparse.

Therefore, as shown in FIG. 7, a basic unit consisting of G picture elements R, G', 'i, and B (the part surrounded by the broken line in FIG. 1 (4) ) is optimal. This can be applied not only to high-definition televisions with a larger number of scanning lines, but also to televisions of a type with a smaller number of scanning lines. Further, when the above-mentioned basic unit shape is a rectangle, it may be set so that the interval in the long side direction (that is, the low frequency component) becomes J-gj cpd.

In addition, without making the width of the /scanning line match the size of the above-mentioned R, G, G;, B basic unit, more narrow R, G,
G7. When using the B basic unit, it spans a width of two or more scanning lines, and when using the smaller I'l, G, G, B basic unit, it spans a width of more than (7 )
Includes R, G, G, and B basic units. the result,
Compared to the optimal pixel arrangement, image quality deteriorates.

It goes without saying that the present invention can be applied not only to color panels using a plasma display method, but also to panels using a liquid crystal display method.

Further, the present invention can also be applied to color printing using R, lc, , and B picture elements.

As mentioned above, according to the present invention, R, G.

The highest image quality can be obtained by arranging the picture elements of B at intervals of 3~(licpa), so it is possible to obtain a color image display device that improves image quality and suppresses increases in production costs. In other words, since it is necessary to have a fine pixel structure, the manufacturing cost is low, and images of high quality can be obtained with such a fine pixel structure.

[Brief explanation of drawings]

The first drawing and (B) are diagrams explaining the pixel arrangement used in one embodiment of the present invention, the first drawing is a diagram showing the spatial frequency characteristics of visual perception, and the third drawing is about the pixel arrangement of the knitted structure. Figure 5 is a diagram showing the interference window and sharpness of picture elements.
6 and 6 are diagrams showing spatial frequency versus evaluation values in various images, and FIG. 7 is a diagram illustrating the relationship between scanning lines and picture elements according to the present invention. Patent applicant: Japan Broadcasting Corporation, 1 See 1,! 7 No. 1 (A) ” (B) 2. Atsushi Katama Shutsuma (cpd) 3. 4 EE Gokan Edition-mI scan i+*min 741

Claims (1)

[Scope of Claims] 1) A color image display device capable of setting the light emitting amount of a plurality of color elements so that a unit picture element consisting of a plurality of color elements maintains white balance with respect to a reference input signal, The unit pixel spacing is 5 both vertically and horizontally at the optimal viewing distance.
A color image display device characterized in that the color image display device is arranged so that the image size is 4'5 cpcl. 2) The unit picture element is composed of R, C, G, and B color elements of equal area and arranged in a square or rectangle, and the luminance per unit area of the color elements is at least R and G are set almost equally, and if the picture element in the above unit is a square, the interval is set as maple; if the picture element in the unit is a rectangle, the interval is set as . The distance in the direction is Ω5-1f
! The first claim characterized in that ;cpa
Color image display device as described in Section 1. 6) The color image display device according to claim 1 and claim 2, wherein the width of the scanning line is equal to the vertical width of the unit picture element. .