JPS583305Y2 - small light emitting display device - Google Patents

Description

[Detailed description of the invention] This invention relates to a small light emitting display device that prevents light from penetrating adjacent segments through the gap between a substrate and a reflector by printing black paint. In display devices, the light emitting efficiency of the light emitting diode element is low, so a reflector is used to reflect the light in order to make effective use of the light. This is a problem especially in small display bodies because it may leak to the adjacent segment via the space between the two segments.

The present invention prevents the above-mentioned light leakage by using a reflector printed with black paint, and will be explained below with reference to the drawings.

FIG. 1 is a perspective view of a Japanese-letter-shaped display device, in which each segment 1 is close to each other but separated by a reflector 2, so there is almost no problem with crosstalk on the surface.

FIG. 2 is a plan view of a reflector 2 made of white synthetic resin, in which each segment 1 has a bar shape on the top surface, but a circular shape on the bottom surface as shown by dotted lines to facilitate the wiring of the light emitting diode elements. Since each segment is close to each other on the bottom surface, if there is light leakage between the segments on the bottom surface, there is a conventional problem of crosstalk, so black paint is printed on the back surface.

FIG. 3 is a sectional view taken along the line AA in FIG. 1, in which a light emitting diode element 4 is wired on a substrate 3, and a reflector 2 is placed on it.

The lower surface of the window hole 5 of the reflector 2 corresponding to the segment 1 in FIG. 1 is semispherical, and the light emitting diode element 4 is wired inside it. The pores do not need to be large and hemispherical.

A scattering sheet 6 is further placed on the reflector 2, and the whole is covered with a colored transparent case 7.

FIG. 4 shows a partially enlarged view of FIG. 3.

In the figure, there is a gap between the reflector 2 whose back surface is coated with black paint 8 and the substrate 3, but it is difficult to eliminate the gap due to manufacturing reasons, and especially the reflector 2 is made of inexpensive synthetic resin. Therefore, a certain amount of gap cannot be avoided.

Generally, plating is applied to the reflector, but plating makes the surface flat and very good, but it is expensive, so as in the example above, a white synthetic resin is used to reflect the reflector. It is better to increase the efficiency and eliminate the need for plating treatment.O Most of the light from the light emitting diode element 4 is reflected by the inner surface of the window hole 5 of the reflector 2 and guided upward, but some light remains. is emitted onto the surface of the substrate 3 and absorbed by the substrate 3, or enters between the substrate 3 and the reflector 2.

FIG. 5 is a diagram showing the state of light leakage. Even if leaked light enters between the substrate 3 and the reflector 2, it is absorbed by the black paint surface 8 on the back surface of the reflector 2 and does not pass through to the adjacent segment.

Furthermore, in order to prevent light leakage, it is possible to apply black paint to the substrate 3 or make it a black substrate, but it is difficult to selectively coat the surface of the substrate 3 other than the light emitting diode elements 4. A black substrate is not preferable because it increases the cost.

As described above, the present invention includes placing a white reflector with a window hole that resembles a light emitting diode element and a black print on the back side on a substrate on which a plurality of light emitting diode elements are arranged, and further A light-scattering material is provided on the back of the reflector, and crosstalk between each segment can be suppressed by simply printing black on the back side of the reflector, making it a simple structure and ideal for small displays.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is a plan view of the reflector shown in Fig. 1, Figs. 3, 4, and 5 are cross-sectional views of Fig. 1. 02 is a reflection 3 is a substrate 4 is a light emitting diode element, 5 is a window hole, and 8 is a black printed layer.

Claims (1)

[Scope of utility model registration request] A white reflector with window holes corresponding to the light emitting diode elements and black printing on the back side is placed on a substrate on which a plurality of light emitting diode elements are arranged, and a light scattering material is further provided on top of the white reflector. Compact light emitting display device 0