JPH067301B2 - Light emitting display - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of light emitting diodes arranged one-dimensionally or two-dimensionally and serves as a pointer portion for indicating a level, or displays letters, numbers, symbols, etc. The present invention relates to a light emitting display device that functions as a unit.

2. Description of the Related Art The range of use of light emitting diodes is not limited to just a point light source, but is widely used as a constituent element of the pointer unit that indicates various levels and as a unit pixel for displaying characters, numbers, symbols, etc. It has come to be used.

For example, in the former light emitting display device for level indication, a plurality of light emitting devices and diodes are arranged one-dimensionally, and the number of light emission of the light emitting diode is changed according to the high (low) of the display level. Instructions are given.

Further, in a light emitting display device for displaying characters, numbers or symbols, a plurality of light emitting diodes are arranged two-dimensionally, and a desired character is selectively emitted by the light emitting diodes.
A light-emitting display such as numbers or symbols is provided.

By the way, in such a light emitting display, a light emitting display unit in which a plurality of light emitting diodes are arranged one-dimensionally or two-dimensionally is required as a constituent element.

FIG. 3 and FIG. 4 are views showing the cross-sectional structure of a light emitting display device having such a light emitting display unit which has been widely adopted.

In the light emitting display device shown in FIG. 3, as shown in the figure, the light emitting diode element 2 is fixed to the light emitting diode element fixing region on the printed circuit board 1, and the electrodes on the light emitting diode element and the wiring layer on the printed circuit board are arranged. A reflection plate 5 having a reflection hole 4 for guiding the light emitted from the light-emitting diode element 2 to the outside is provided on the upper part of the assembly structure formed by electrically connecting the metal wire with the metal thin wire 3. The inside of 4 is filled with a resin 6 containing a light-scattering substance, and a light-scattering sheet 7 is provided on the uppermost part.

Further, as shown in FIG. 4, a structure in which the inside of the reflection hole 4 is a completely hollow portion and the other structure is the same as that shown in FIG. 3 is also adopted.

Problems to be Solved by the Invention In the light emitting display device having the structure shown in FIG. 3, since the light from the light emitting diode element is scattered by the resin 6, the uneven brightness of the light scattering sheet surface serving as the light emitting surface is eliminated. However, since the inside of the reflection hole 4 is completely filled with the resin, the light emitting diode element cannot be replaced once it is completed as a light emitting display device. There is a problem that reproduction becomes difficult when, for example, one of the elements fails.

In the light emitting display device having the structure shown in FIG. 4, there is no resin inside the reflection hole 4, and the light emitting diode element 2 can be replaced. Therefore, when the light emitting diode element 2 fails, reproduction is easy. Further, it is possible to prevent a decrease in the brightness of the light emitting surface. However, since there is no light scattering by the resin, uneven brightness occurs on the light emitting surface. That is, the luminance is high in the light emitting surface portion directly above the light emitting diode element, while the luminance is low in the surrounding light emitting portion. In order to eliminate this inconvenience, it is sufficient to use the light scattering sheet 7 having a large light scattering effect, but if the light scattering effect is enhanced, the luminance of the light emitting surface is significantly reduced.

Means for Solving the Problems The light emitting display device of the present invention has been made for the purpose of eliminating all the problems existing in the conventional light emitting display device, and a plurality of light emitting diodes are fixed on the printed circuit board. A reflector having a reflection hole formed on the assembly structure in which the electrode on the light emitting diode and the wiring layer on the printed circuit board are connected by a metal wire at a position corresponding to the fixing position of each light emitting diode. Further, the inside of the reflection hole is filled with a resin to which a light scattering material is added, leaving a space around the light emitting diode and the metal wire located inside the reflection hole.

Action According to this structure, direct contact between the light emitting diode and the metal wire and the resin is cut off, and the light scattering effect by the resin is also exhibited.

Example Hereinafter, a light emitting display device of the present invention and a method for manufacturing the same will be described in detail with reference to FIGS. 1 and 2.

FIG. 1 is a sectional view showing the structure of the light emitting display device of the present invention, and its basic structure is almost the same as the conventional light emitting display device shown in FIG. That is, a plurality of light emitting diode elements 2 are fixed to the light emitting diode element fixing region on the printed circuit board 1, and the electrodes on these light emitting diode elements and the wiring layer on the printed circuit board are connected by the thin metal wires 3. A reflection plate 5 having a reflection hole 4 is arranged on the upper part of the assembly structure formed by the above, and the reflection hole 4 is filled with a resin 6 containing a light diffusing substance. . Although the light scattering sheet 7 is attached to the uppermost portion, the light scattering sheet 7 is not an essential component.

By the way, in the light emitting display device of the present invention having such a structure, as shown in the drawing, the hollow portion 8 is formed around the light emitting diode element 2 and the thin metal wire 3, and the contact with the resin 6 is completely cut off. In addition, the surface of the resin 6 on the side facing the light emitting diode element 2 has a lens shape. In this respect, the structure is different from that of the conventional light emitting display device.

FIG. 2 is a view showing a process of manufacturing the light emitting display device having the structure shown in FIG. 1. As shown in FIG. 2 (a), a reflective plate 5 having a predetermined number of reflection holes 4 is formed. After attaching the light scattering sheet 7, the reflection plate 5 is installed with the mounting surface side facing down, and the resin 6 containing the light scattering substance in the reflection hole 4.
Inject. What is important in this injection is to keep the injection amount of the resin 6 in the middle of the reflection hole 4.

FIG. 2 (b) is a view showing a state after the resin 6 injected by establishing such a relationship is cured and the resin 6 has a lens-like surface shape as shown in the figure. A vacant space is left behind.

If the light scattering sheet 7 is not used, a sheet that closes one opening may be attached instead of the light scattering sheet 7 and the sheet may be removed after the resin 6 is cured.

Then, as shown in FIG. 2 (c), a plurality of light emitting diode elements 2 are fixed to a predetermined portion of the printed circuit board 1, and a metal is provided between the electrodes on the light emitting diode elements and the wiring layer on the printed circuit board. The assembly structure formed by connecting the thin wires 3 and the reflecting plate 5 are opposed to each other, and the both are aligned so that the voids of the reflecting holes which remain without being filled with the resin 6 are located right above each light emitting diode. After that, the light emitting display device having the structure shown in FIG. 1 is completed by closely adhering and fixing. By the way, in the case of closely fixing the both, any method such as a method of using an adhesive, a method of screwing with a screw, or a method of fixing with a pressing force from the outside may be adopted.

EFFECTS OF THE INVENTION In the light emitting display device of the present invention, since the resin having the light scattering effect is present in the reflection hole of the reflection plate, it is possible to realize a light emitting surface with less unevenness of brightness, and when viewed from the outside, a hollow portion Since the interface with the resin can be seen as the light emitting part, the angle at which the display can be confirmed widens, and because the light emitting diode element and the thin metal wire are not in contact with the resin, the specific light emitting diode element can be replaced by removing the reflector. There are many effects such as the fact that the stress from the resin is not applied to the light emitting diode element and the thin metal wire.

[Brief description of drawings]

1 is a diagram showing a cross-sectional structure of a light emitting display device of the present invention, and FIGS. 2 (a) to 2 (c) are diagrams for explaining a manufacturing process of the light emitting display device shown in FIG. 1, FIG. FIG. 4 is a sectional view showing the structure of a conventional light emitting display device. 1 ... Printed circuit board, 2 ... Light emitting diode element, 3 ...
… Metal fine wire, 4 …… Reflecting hole, 5 …… Reflector, 6 …… Resin, 7 …… Light scattering sheet, 8 …… Hollow part.

Claims (1)

[Claims] 1. A plurality of light emitting diodes are fixedly mounted on a printed circuit board, and each of the light emitting diodes is mounted on an assembly structure in which electrodes on the light emitting diodes are connected to a wiring layer on the printed circuit board by a metal wire. A reflection plate having a reflection hole is attached at a position corresponding to the fixed position of the diode, and a light scattering substance is added to the inside of the reflection hole leaving a space around the light emitting diode and the metal wire. A light emitting display device characterized in that it is filled with a filled resin.