JPH0428147Y2 - - Google Patents

Description

[Detailed explanation of the idea] <Industrial application field> The present invention relates to a display device.

<Prior Art> FIG. 1 is an explanatory diagram schematically showing an example of a conventional display device, in which FIG. 1A shows a plan view, and FIG.

In the figure, 1 is a printed circuit board on which a light emitting diode 2 is provided, 3 is a housing with a reflective surface formed inside, 4 is a transparent resin, and 5 is a scattering plate. As is clear from the figure, the light emitting diode 2
The distance from the light emitting diode 2 to the scattering plate 5 is shortest immediately above the light emitting diode 2. Therefore, the part corresponding to the upper part of the light emitting diode 2 shown by diagonal lines in FIG. 1A becomes brighter than the other parts. As described above, conventional display devices have the disadvantage that it is difficult to obtain a display with uniform brightness over the entire surface.

On the other hand, in order to eliminate the above drawbacks, the distance between the light emitting diode 2 and the scattering plate 5 may be increased, or
The use of a scattering plate with low light transmittance causes another problem in that the brightness of the display device is reduced, especially in the former case since the thickness of the device increases;
There is also the problem that it cannot be used in electrical equipment with thin specifications.

<Purpose> This invention does not significantly reduce brightness,
Another object of the present invention is to provide a display device that can provide a display surface with uniform brightness without increasing the thickness of the device.

<Structure> This invention is a display device that includes a housing, a printed circuit board, a plurality of light emitting diodes, and a light-transmitting insulating resin, and the housing has a display surface that has a rectangular opening as a whole. A plurality of eaves portions are formed from a white insulating resin and are formed into a bottomed rectangular shape having a display surface opened in a bottomed rectangular shape having The light emitting diode has one long side arranged in parallel, and a reflective surface whose bottom part is curved radially to make it shallower from the long side to the other opposite long side, and the light emitting diode is located in the eaves part. The light-transmitting resin is attached to the printed circuit board at the deepest position and is not visible from the display surface in plan view, and the light-transmitting resin fills the space formed by the eaves part and the reflective surface. The light emitted from the light emitting diode directly hits the reflective surface, is reflected by the reflective surface, and exits to the display surface, and the other is the first light that once enters the eaves, is reflected by the eaves, and enters the reflective surface. The second light is reflected by the reflective surface and exits to the display surface, and the third light is directly incident on the display surface from the light emitting diode.

<Embodiment> FIG. 2 is an explanatory diagram schematically showing an embodiment of this invention, and FIG. 2A is a plan view, and FIG. 2B is a sectional view taken along line A-A.

This device includes a housing 13, a printed circuit board 11 (111 is a terminal of the printed circuit board 11), a plurality of (two in the illustrated example) light emitting diodes 12, and a light-transparent insulating resin 14. There is.

The housing 13 is made of a white insulating resin and has a rectangular shape with a bottom and a display surface 15 having a rectangular opening. Reference numeral 131 denotes an eaves portion formed by hollowing out the inside of one long side of the housing 13 into a substantially 1/4 spherical shape, and a plurality of eaves portions 131 (two in the illustrated example) are formed.

Reference numeral 132 denotes a reflective surface, and the reflective surface 132 has a shape in which the bottom is curved parabolically and becomes shallower from the long side on which the eaves are formed to the opposite long side.

The mounting position of the light emitting diode 13 to the printed circuit board 11 is hidden inside the eaves section 131.
That is, the position is the innermost position of the eaves part 131, is not visible from the display surface 15 in plan view, and is attached to the printed circuit board.

14 is a translucent resin such as epoxy resin, and as shown in FIG.
It fills the space formed by the reflective surface 132.

The light emitted from the light emitting diode 13 is reflected on the reflective surface 13
The first light is directly incident on the display surface 15 , reflected by the reflective surface 132 , and a portion of the first light is incident on the eaves section 131 , is reflected by the eaves section 131 , and then enters the reflective surface 132 .
It consists of a second light that is reflected by the reflective surface 132 and exits to the display surface 15, and a third light that enters the display surface 15 directly from the light emitting diode 13.

<Effects> According to this invention, the light emitting diode is hidden behind the eaves and installed in a position that cannot be seen, so that there is no light emitted directly above from the light emitting diode. Direct light from the light emitting diode does not exit perpendicularly to the display surface, but rather in an oblique direction. Furthermore, since there is a so-called dome-shaped eave above the light emitting diode, the light emitted from the light emitting diode is reflected in various directions by the surface of the eave.

Further, by configuring the eaves portion and the reflective surface as described above, the first, second, and third lights respectively exit the display surface, so that a display with uniform brightness can be obtained. Through experiments, the inventor was able to confirm that much more uniform brightness can be obtained compared to conventional display devices.

The resin filling the housing may be a transparent resin, and therefore, a thin display device can be obtained without any reduction in brightness.

[Brief explanation of the drawing]

FIG. 1 is an explanatory view schematically showing a conventional display device, and FIG. 2 is an explanatory view schematically showing an embodiment of this invention. 11...Printed circuit board, 12...Light emitting diode, 13...Housing, 131...Eave part, 1
32... Reflective surface, 14... Transparent resin, 15...
Display surface.

Claims (1)

[Scope of utility model registration request] The display device includes a housing, a printed circuit board, a plurality of light emitting diodes, and a light-transparent insulating resin, wherein the housing is formed in a bottomed rectangular shape having a rectangular opening display surface. It is made of a white insulating resin, and has a plurality of eaves cut out in an approximately 1/4 spherical shape in parallel on one long side, and the other long side facing from the long side. the light emitting diode is located at the innermost position of the eaves and is not visible from the display surface in plan view; It is attached to a printed circuit board, and the light-transmitting resin fills a space formed by the eaves part and the reflective surface, and the light emitted from the light emitting diode enters the reflective surface and is reflected by the reflective surface. A first light that exits to the display surface, a second light that once enters the eaves, is reflected by the eaves, enters the reflective surface, is reflected by the reflective surface, and exits to the display surface, and a light emitting diode. and a third light directly incident on the display surface.