JPH07129101A - Display device - Google Patents

Abstract

PURPOSE:To improve visibility of a display device in which color LEDs are used. CONSTITUTION:It is an example in which 3X3 LED matrix is composed as picture elements 10, 10'. A three-color LEDT is arranged at the center of the picture elements 10, 10'. In (a), four blue LEDs are arranged at four corners and two green and red LEDs are arranged respectively per opposite side. The three-color LEDT is made by packaging the green and red two-color LEDs and the blue LED into one package simultaneously, and only-one package can display all colors. However, since light emission luminance of the blue LED is extremely low, only dark three-color LEDT can be realized naturally. Accordingly, a display device is not composed of the three-color LEDT only, but individual single color LED is arranged around the three-color LEDT to obtain well- balanced luminance. In (b), two green and red LEDs are arranged respectively on opposite angles at four corners, and the remaining four LEDs are composed of the blue LEDs. As shown in the above composition, insufficient luminance of the blue LED is supplemented by arranging many blue LEDs to obtain good balance of three colors and improve visibility.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly to a color display device using an RGB collective lamp using LEDs as a display unit (dot or pixel).

[0002]

2. Description of the Related Art After LEDs have realized blue in addition to red, yellow, and green, the so-called RGB primary colors have been completed and LEDs have been used for color display. Therefore, it is possible to display LEDs in color by arranging LEDs of each of the three primary colors as a dod matrix to form one pixel (1 dot). However, unlike the color dots on color TVs, LEDs are large, so
It has been found that some placement selection is required to mix mixed colors. Also, from the past, red and green LE
In a display device using D, red and green LEDs are configured in one package, and a display device configured as a dot matrix using this is proposed (for example, Japanese Utility Model Laid-Open No. 525483). Fig. 6 is a block diagram of the display panel, in which three LEDs are one pixel. One of them, LED 61, is composed of LEDs that emit two wavelengths of red and green. That is, the LED element 61 including the red and green elements is incorporated in one package, and the intermediate color orange can be developed. 3 LEs in this arrangement
The D's are grouped together to form a single pixel, but the blue LED is not used and full-color display is not possible.

[0003]

[Problems to be Solved by the Invention] However, in the case of a dot matrix using LEDs of the three primary colors of RGB, a blue LED is used.
Is still not bright enough with the current technology, red,
With a 1-dot configuration using one green LED and one blue LED, it is necessary to suppress the brightness of red and green for display, and there is the problem that only a dark display with insufficient brightness can be performed as a whole. In addition, since individual LEDs are collectively displayed, there is a problem that it is difficult to form a fine color dot display like a color liquid crystal display device. Therefore three colors
Although it may be possible to use LEDs, it is not easy to incorporate three chips into a small package, and because it is difficult to obtain blue brightness and it is difficult to manufacture, it is more expensive than other LED elements and difficult to implement. There is also a problem.

Therefore, an object of the present invention is to treat a display on a large scale, and assume a large display with sufficient brightness from a distance and sufficient color recognition.
It is to provide an LED display device with a collective lamp.

[0005]

In order to solve the above problems, the structure of the present invention is a display device for displaying a color by arranging a plurality of LEDs of three primary colors to form one pixel. Arrange the LEDs of the pixel from the top 3 x 3
A matrix of 2 pixels with 2 red LEDs and a green LE
Use two D, four blue LEDs, and one red, green, and blue three-color LED set, and arrange the three-color LEDs in the center of the matrix so that the color arrangement is symmetrical. Is. In the configuration of the related invention, the configuration is such that the blue LED is four at the four corners of the matrix, the green LED is two in the middle of the opposite side, and the red LED is the remaining two. Is characterized in that. Another configuration of the related invention is also
In the configuration, the blue LEDs are four in the middle of each side of the matrix, the green LEDs are two diagonally opposite corners, and the red LEDs are the remaining two LEDs. It is characterized in that

Further, the structure of another related invention of the present invention is that the control circuit for the three-color LED is a circuit for always lighting the instructed color mixture when the display device is turned on. Is characterized in that. In another configuration, the arrangement is such that the symmetry axes or directions of the symmetry are 90 ° to each other.
Alternatively, the blue LED is a gallium nitride semiconductor, and the blue LEDs are alternately arranged in an arrangement rotated by 180 °.

[0007]

[Function] The three-color LED in the center of the matrix of pixels is turned on for any color instruction during display, and the center of each pixel is turned on. The blue of this three-color LED is particularly weak as the brightness, so the brightness is reinforced by four individual blue LEDs around the LED. In addition, two other red and green LEDs supplement the brightness of the three-color LED.

[0008]

Since the three-color LED is used at the center of the matrix of pixels, the center of each pixel is turned on by any color instruction, and the coloring and display are balanced for each pixel, and the viewing distance is shortened. In addition, it is practical because the surrounding LEDs are supplemented with sufficient brightness.

[0009]

EXAMPLES The present invention will be described below based on specific examples. Figure 1 shows an example of a 3 x 3 LED matrix configured as pixels. In the center of the matrix, three-color LEDs are arranged. In Figure 1 (a), four blue LEDs are provided at the four corners of the surrounding area, with four opposite sides. Two green LEDs and two red LEDs are arranged. A three-color LED is a package of a conventional red and green bi-color LED and a blue LED at the same time, and a single package can express full color. However, since the emission brightness of the blue LED is extremely low, it is not possible to achieve a well-balanced emission without a design that suppresses the brightness of red and green, and inevitably only dark three-color LEDs can be realized. Therefore, the brightness is balanced by arranging individual single-color LEDs around instead of using only three-color LEDs. In Fig. 1 (b), two red and green LEDs are arranged on the opposite corners of the four corners, and the remaining four LEDs are composed of blue LEDs. By arranging a large amount of blue as in these configurations, the lack of brightness of blue is compensated, the three colors are balanced, and the visibility is improved.

FIG. 2 shows one module 20 in which the 3 × 3 LED matrix of FIG. 1 is used as a pixel and this is used as a 16 × 16 pixel matrix. A large number of full-color display panels can be configured by arranging a large number of modules 20 of this pixel matrix. Here, when each LED has a diameter of 4 mm and each pixel has a size of 13 mm square, the module 20 of FIG.
The size is 240 mm square with a pitch of 15 mm between pixels.
Since one module can display one character, for example, vertical 3
If you arrange 0 modules, 40 modules horizontally, 40 modules 30
It will be a full-color large panel with a length of 7.2 m and a width of 9.6 m that can display characters on a line. Since each module is arranged exactly, it is possible to display not only letters but also various patterns and patterns in color.

As a constitution of one pixel, as shown in FIG. 1, symmetry is given as a color arrangement. Symmetry is a desirable condition for the three colors to be uniform. Since the way of taking this symmetry changes depending on the number and arrangement of the LEDs used, the way of mixing each color changes depending on the configuration of one pixel. Figure 4
Is shown in the chromaticity diagram. The results of the luminance and chromaticity values of the LEDs of each color were measured with other numbers and arrangements, and it was confirmed by the inventors that the case of FIG. 1 is the best. Although other arrangements are possible, some disadvantages such as an increased distance of color mixture are recognized.

Further, when forming a module by arranging pixels, periodicity and symmetry are taken into consideration. Normally, the same pattern may be formed continuously so that the same pattern becomes periodic. However, in some cases, when the arrangement of Fig. 1 (a) is arranged in a horizontal row and the central LED is green, the green LE
Since the D's are arranged in a line in the center, the color mixing property may be affected. Therefore, the periodic arrangement is also changed and formed. That is, FIG. 3 (a) and FIG. 3 (b)
As shown in, the symmetry axes of the pixels are alternated by 90 ° or 180
By changing the arrangement, it is possible to reduce the influence of each adjacent pixel and obtain a uniform color mixture. Pixel symmetry does not always have a perfect axis of symmetry, but may have directionality, so it is possible to adopt the arrangement shown in Fig. 3 (b). It may be an array rotated by 90 °.

Further, in the case of the pixels used in the embodiment, the entire color-developable range is a chromaticity diagram of FIG. 4, and is a color display in a range surrounded by a triangle like a solid line. Of course, the 2D used has a different emission characteristic, for example blue L
If the ED is pixel-configured with a blue-green gallium nitride semiconductor LED (BG in FIG. 4), the color expression will be changed within the chromaticity range of the triangle surrounded by R, G, and BG in FIG. Alternatively,
Although the structure is not shown, if blue is used not only with blue LED but also with a pair of blue-green gallium nitride semiconductor LED, a display range of substantially 4 colors is obtained, including the range shown by the dotted line in FIG. The choice of expressions will expand.

As described above, a three-color LED is used in the center, and a plurality of single-color LEDs are supplemented to form one pixel. By using more blue LEDs, which are not particularly bright, than other-color LEDs, By making the balance, one pixel can have sufficient brightness, and a display device useful for a full-color large-sized display panel or the like can be provided.

[Brief description of drawings]

FIG. 1 1 pixel (1 dot) of an LED which constitutes the present invention
Diagram showing the arrangement of FIG.

FIG. 2 is a configuration diagram of a dot matrix using the dot configuration of the present invention.

FIG. 3 is an explanatory diagram showing an arrangement example of a dot matrix.

FIG. 4 is a CIE chromaticity diagram showing the emission characteristics of the LED used in the present invention.

[Explanation of symbols]

 10, 10 'pixel 20 16 × 16 pixel matrix module BG GaN semiconductor blue-green LED B blue LED G green LED R red LED

Claims (6)

[Claims] 1. A display device for displaying a color by arranging a plurality of pixels of a plurality of LEDs of three primary colors and arranging the plurality of pixels, and the LEDs of the pixels are arranged in a matrix of 3 × 3 from the top. , The pixels are 2 red LEDs, 2 green LEDs, 4 blue LEDs
A display device characterized in that one LED of one set of three colors of red, green, and blue is used, the three-color LED is arranged in the center of the matrix, and the color arrangement is symmetrical. 2. The configuration is such that the blue LEDs are four at four corners of the matrix, the green LEDs are two in the middle of opposite sides, and the red LEDs are the remaining two. The display device according to claim 1, wherein the display device is a display device. 3. The configuration is such that the blue LEDs are four in number, one in the middle of each side of the matrix, the green LEDs are two diagonally opposite corners, and the red LEDs are The display device according to claim 1, wherein the display device has the remaining two. 4. The display device according to claim 1, wherein the control circuit of the three-color LED is a circuit that constantly lights the instructed color mixture when the display device is turned on. 5. The display device according to claim 2, wherein the array is an array in which the symmetry axes or directions of the symmetry are alternately gathered in an arrangement in which the symmetry axes or directions are rotated by 90 ° or 180 °. . 6. The display device according to claim 1, wherein the blue LED is a gallium nitride semiconductor.