JPS6328456Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a light emitting diode device having a uniformly bright illumination surface with a sufficiently large area compared to a light emitting diode.

B. Conventional technology As shown in FIG.
A substantially truncated pyramid reflector 15 covering the light emitting diode 13 has been used. However, when the display area becomes larger or uniform high illuminance is required over the entire illumination area, the difference between the darkness at the periphery of the display surface or illumination surface and the brightness almost directly above the light emitting diode 13 becomes noticeable. Even if a light diffusion sheet or lens means (none of which are shown) is used, the brightness cannot be made very uniform. This is particularly noticeable when the display surface is square.

Therefore, we have attempted methods of effectively utilizing light by providing an intervening layer between the substrate and the reflector or by integrally molding them (for example, Japanese Patent Application Laid-Open No. 48-46288), and we have tried to create a lens effect on the light-emitting diode. A method of providing a transparent resin cord (for example, Japanese Unexamined Utility Model Publication No. 54-48587) has been proposed. However, it has not yet been put to practical use because the light emitting diode is too small and it is difficult to mold a resin mold that provides the desired light distribution.

C. Problems to be solved by the invention This invention has been made in consideration of the above points.
In particular, the aim is to improve the uniformity of the spread of light by increasing the efficiency of light utilization near the bottom of the light emitting diode.

D. Means for Solving the Problems The present invention provides an opaque resin from the reflective surface on the substrate side (upper bottom side) of the reflector to the exposed surface of the substrate, and extends the transparent resin covering the light emitting diode to this opaque resin. More preferably, when the reflector is in the form of a truncated pyramid, the opaque resin is arranged on each side facing the reflective surface to form a substantially half-moon shape, and the transparent resin is made substantially convex.

E. Effect: As a result, the opaque resin not only prevents light from dissipating between the reflector and the substrate, but also serves as a low reflector that guides the light emitted diagonally downward from the light emitting diode toward the display and illumination direction. do. By extending the transparent resin to the opaque resin, the transparent resin functions as a light propagation path and a light diffusing plate. Therefore, as a synergistic effect, it is equivalent to having a strong point light source at the top of the reflector and a surface light source around it, and the light is efficiently and spread out toward the bottom of the reflector.

Furthermore, if the reflector is pyramid-shaped, such as when the corners of the display surface are at right angles or acute angles, if the opaque resin is approximately semicircular, the transparent resin will follow its shape as it approaches the reflective surface. The width increases, and the role of the light diffusion plate described above increases the effect of directing light toward the edges rather than the center of the bottom, and this opaque resin supports the bottom surface of the transparent resin, making it easier to form a convex shape. You can easily obtain the lens effect that was previously used.

(F) Embodiment FIG. 2 is a plan view of a light emitting diode display according to an embodiment of the present invention, and FIG. 3 is a sectional view taken along the line A-A' in FIG. In the figure, reference numeral 1 denotes a substrate such as a printed circuit board made of paper phenol resin, glass epoxy resin, etc. as a base material, and has conductive foils 2, 2, such as copper patterns plated on the surface. Reference numeral 3 denotes a light emitting diode made of gallium phosphorus or the like, which is placed and fixed on a conductive foil 2 and wired with a thin metal wire 4 or the like. Reference numeral 5 denotes a reflector made of a white resin molded product having reflective surfaces 6, 6, etc. made up of four bent slopes, and since the interior of the reflective window is approximately pyramid-shaped, it has a wide opening on the light emission side. The opening on the light source side will be referred to as the lower base and the opening on the light source side as the upper base.
The substantially pyramid-shaped lower base 7 is left open to serve as a display surface, and the light emitting diode 3 is placed on the substrate 1 so as to be located approximately at the center of the upper base. 9, 9 are opposite sides 8, 8 of the upper base of the reflector 5
The light-emitting diode 3 is an opaque resin that extends inward from each of the substrates 3 in a substantially half-moon shape, and is made of colored epoxy resin or the like.
It is coated to a thickness of 2/3 to 1/10 of the height. Incidentally, when the shape of the lower base 7, which is a light extraction portion such as a display surface, is rectangular, the opposing sides 8, 8 are preferably sides corresponding to the long sides. 10 is a transparent resin such as silicon that covers the light emitting diode 3 and the opaque resins 9, 9, and has a convex shape to cover the light emitting diode 3, and has a spade-shaped cross section due to the opaque resins 9, 9.

G. Effect of the invention As described above, the light-transmitting resin is reflected at the interface with the opaque resin, and is sufficiently scattered within the light-transmitting resin.
Since it contributes to display and illumination, light usage efficiency is high and uniformity is promoted. The translucent resin is supported by the opaque resin and tends to form a convex shape, thereby increasing the lens effect.Moreover, in the longitudinal direction, the transparent resin becomes wider towards the tip, so the translucent resin It serves to spread light approximately corresponding to the shape (square) of the display surface and illumination surface (lower base).

[Brief explanation of drawings]

Figure 1 is a sectional view of a conventional display, Figure 2 is a plan view of a light emitting diode display according to an embodiment of the present invention, and Figure 3 is a cross-sectional view of a conventional display.
The figure is a sectional view taken along line A-A' in FIG. 1... Substrate, 2, 2... Conductive foil, 3... Light emitting diode, 5... Reflector, 6, 6... Reflective surface, 7
...Lower base, 9,9... Opaque resin, 10... Transparent resin.

Claims (1)

[Claims for Utility Model Registration] 1. A reflector in which both a lower base and an upper base smaller than the lower base are open and the inner wall serves as a reflective surface, a substrate disposed on the upper base side of the reflector, and a light emitting diode placed on a substrate and wired so as to be located approximately in the center of the open top of the reflector;
A light emitting device comprising: an opaque resin that extends from the reflective surface on the upper bottom side of the reflector to the surface of the substrate exposed from the upper bottom; and a transparent resin that covers the light emitting diode and extends to the opaque resin. diode device. 2. The reflector has a substantially truncated pyramid formed by an upper base, a lower base, and a reflective surface, and the opaque resin is provided in a substantially half-moon shape facing toward the light emitting diode from each of the opposing sides of the upper base of the reflector. 2. The light emitting diode device according to claim 1, wherein the transparent resin has a substantially convex shape with its apex above the light emitting diode.