JPH07129097A - Display device - Google Patents

Abstract

PURPOSE:To compose LED picture elements suitable for color display. CONSTITUTION:(a) is a first embodiment of 3X3 matrix picture element in which four blue LED are arranged at four corners, three green LED are arranged at a central column and two red LED are arranged at the centers of remained opposite sides. (b) is a second embodiment in which five blue LED are arranged in a cross shape at the center, two green and two red LED are respectively arranged at the four corners diagonally. Dots matrix is composed of the arrangement of the picture element 10 or 10' as a dot and many dots are arranged to form a large-sized display panel. As a constitution of a picture element, color arrangement has symmetry and in such a manner, the picture elements are excellent in color mixing and white mixing is realized in a short distance.

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 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. In particular, the shape of a cannonball-shaped LED (see Fig. 5) is large, and its layout is important. In addition, conventionally, there has been proposed a display device using red and green LEDs, in which the red and green LEDs are configured in a single package, and using this, a display device configured as a dot matrix (for example, actual Kaihei 5-25483, etc.). Figure 6
Is a configuration diagram of the display panel, and 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. In this arrangement, three LEDs are grouped together to form one pixel, but the blue LED is not used and full-color display is not possible.

[0003]

However, in the case of a dot matrix using the three primary colors of RGB, the blue LED is not yet sufficiently bright, and red, green and blue LEDs are used one by one. With the pixel configuration, it is necessary to suppress the brightness of red and green for display in order to balance the color mixture, and there is a problem that the display as a whole has insufficient brightness. Moreover, because individual LEDs are displayed collectively,
There is a problem that it is difficult to form a fine color dot display like a color liquid crystal display device.

Therefore, an object of the present invention is to consider that the display is handled only on a large scale, and assumes a large display which is sufficiently bright from a distance and is capable of sufficiently recognizing colors.
It is to provide an LED display device with RGB collective lamps.

[0005]

In order to solve the above-mentioned problems, the structure of the present invention has a color display in which a plurality of LEDs of three colors of red, green and blue are used as one pixel and a plurality of the pixels are arranged. In the display device described above, the LEDs of the pixels are arranged in a matrix of 3 × 3, and one pixel is configured in a number arrangement having a uniform color mixture and symmetry. Also, in the configuration of the related invention, the arrangement of the number is such that the blue LEDs are four at the four corners of the matrix, the green LEDs are three in a central row, and the red LEDs are the remaining two. That is. Another configuration of the related invention is also that the number arrangement is such that the blue LEDs are arranged in a central cross of the matrix.
It is characterized in that the green LEDs are arranged in two of the four corners and the red LEDs are arranged in two of the remaining four corners.

The structure of another related invention of the present invention is further characterized in that the array of the pixels is an array in which the symmetry axes or directions of the symmetry are alternately gathered at 90 ° or 180 ° with respect to each other. According to yet another configuration, the blue LED is a gallium nitride semiconductor.

[0007]

According to the arrangement of the present invention, since a plurality of LEDs are used, display can be performed with sufficient brightness, and the three primary colors are mixed at an appropriate distance and recognized as one pixel.

[0008]

EFFECTS OF THE INVENTION In a 3 × 3 matrix of LEDs with a diameter of 3.8 mm, about 5 in white, which shows the homogeneity of the mixture of each color.
m is recognized as one pixel, and effective color mixing is achieved.
It is effective for large display panels. In addition, a full-color display device with sufficient brightness is realized.

[0009]

EXAMPLES The present invention will be described below based on specific examples. FIG. 1 (a) shows a first embodiment of a pixel of the 3X3 matrix of the present invention, in which four blue LEDs are arranged at four corners, three green LEDs are arranged in one row in the center, and two red LEDs are arranged in the middle two of the opposite sides. led
Is arranged. In addition, as shown in FIG. 1 (b), as a second embodiment, five blue LEDs are arranged in a cross shape in the center, and green and red LE
Two D's are placed on each of the four corners diagonally. This pixel 10, 10 'is arranged as 1 dot and 16
FIG. 2 shows a x16 dot matrix configured to display one character or character. In FIG. 2, the notation of the arrangement of LEDs within one pixel is omitted except for the upper left. This 16x16 dot matrix is 1
If a large number of display modules are arranged, a large display panel is formed.

When the size of one LED is 3.8 mm and the size of one pixel is 13 mm square, the display module 20 of FIG.
The size is mm square. One module can display one character, so for example, 30 modules vertically, 40 modules horizontally, if you arrange the modules, you can display 40 characters and 30 lines of characters, vertical 7.2 m,
It will be a large full-color panel with a width of 9.6 m. Since each display module is arranged exactly, it is possible to display not only letters but also various patterns and patterns in color.

As shown in FIG. 1 as a structure of one pixel, symmetry is provided as a color arrangement. Symmetry is a desirable condition for the three colors to be uniform. This symmetry is
Since it depends on the number and arrangement of LEDs used, the way of mixing each color changes depending on the configuration of one pixel. FIG. 3 shows the result of actually measuring the degree of color mixing in the case of the arrangement of FIG. FIG. 3 shows the luminance and chromaticity numerically, and FIG. 3 shows 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, disadvantages such as an increased distance for color mixing have been recognized.

With the color mixing of the one pixel configuration of each embodiment, white mixing is realized by lighting LEDs of each color substantially evenly. The chromaticity coordinate values at that time are as shown in FIG.
In the case of (a), it is the closest to the ideal white (x = 1/3, y = 1/3), and then in the case of FIG. 1 (b). In the case of the pixels used for measurement, the entire color-developing range is a chromaticity diagram, and is approximately the same as in FIG.
The color is displayed in the range surrounded by the triangle like the solid line. Of course, the LEDs used have different emission characteristics,
For example, if a pixel is composed of a gallium nitride semiconductor LED,
The color expression is changed within the range of the chromaticity of the triangle surrounded by the dotted line in FIG.

Further, when forming a module by arranging pixels, it is necessary to consider periodicity and symmetry. Normally, the same pattern may be formed continuously so that the same pattern becomes periodic. However, in some cases, FIG.
When the arrangement of (a) is arranged in a horizontal row, the green LEDs are arranged in a central row, which may affect the color mixing property.
Therefore, the periodic arrangement is also changed and formed. That is, as shown in FIGS. 4 (a) and 4 (b), by arranging the symmetry axes of the pixels alternately by 90 ° or 180 °, the influence of each adjacent pixel is mitigated and homogenized. It is possible to obtain a mixed color. 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. 4 (b). It may be a 90 ° rotated array.

As described above, one pixel can be made to have sufficient brightness by constructing one pixel with a plurality of LEDs, and by using more blue LEDs, which have no particular brightness, than LEDs of other colors, one pixel can have sufficient brightness. A display device useful for such purposes 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 block diagram of a dot matrix using the pixel structure of the present invention.

FIG. 3 is a chromaticity diagram of one pixel according to the present invention.

FIG. 4 is an explanatory diagram showing an arrangement example of a dot matrix.

FIG. 5 is a schematic diagram of the structure of a cannonball-shaped LED.

FIG. 6 is an explanatory diagram showing a pixel configuration example of a conventional dot matrix.

[Explanation of symbols]

 10, 10 'pixel 20 display module BG GaN semiconductor blue-green LED B1 SiC semiconductor blue LED B2 PN semiconductor blue LED G green LED R red LED 51 LED chip 61 dual wavelength LED

Claims (5)

[Claims] 1. A plurality of LEDs of three colors, red, green and blue
In a display device for displaying a color by arranging a plurality of pixels and arranging a plurality of the pixels, the arrangement of the LEDs of the pixels is a 3 × 3 matrix, and one pixel is arranged in a number arrangement having a uniform color mixture and symmetry. A display device characterized by being configured. 2. The number arrangement is such that the blue LEDs are four at four corners of the matrix, the green LEDs are three in a central row, 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 number arrangement is such that the blue LEDs are five in the center cross of the matrix, the green LEDs are two out of four corners, and the red LEDs are two in the remaining four corners. The display device according to claim 1, wherein the display device has the following arrangement. 4. The array of pixels according to claim 2, wherein the array of pixels is an array in which the symmetry axes or directions of the symmetry are alternately gathered in a configuration in which the symmetry axes or directions are rotated by 90 ° or 180 °. Display device. 5. The display device according to claim 1, wherein the blue LED is a gallium nitride semiconductor.