JPS5921417Y2 - light emitting diode display - Google Patents

Description

[Detailed description of the invention] The present invention relates to a light emitting diode display device, particularly when displaying small characters, there is no brightness unevenness on the display surface, and the light emitting diode display device has a reflective window suitable for mass production. .

Conventionally, there have been three methods for displaying small characters using light emitting diodes:

The first is a method using a monolithic light emitting diode, the second is a method in which a light emitting diode is placed approximately at the center of the bottom of the box and a predetermined cutout is provided on the surface of the box, and the third is a method in which a monolithic light emitting diode is used.
As shown in the figure, this method uses a reflective frame 13 that has a large opening only in the portion surrounding the light emitting diode 12.

However, in the first method, monolithicization of the light emitting diode is an advanced technology, and as the size of the display increases, the area of the light emitting diode substrate that is not used for display increases, making it extremely expensive. became.

Although the second method is easy to manufacture, it is brightest right above the light emitting diode and becomes dark at the edges of the box due to scattering of light, resulting in significant uneven brightness on the display surface.

In the third method, there is less uneven brightness, but when manufacturing the reflective frame, the mold for the reflective window is a substantially trapezoidal mold 18 for making a reflective mirror, as shown in Figure 2, and a mold 18 for making the bottom part wider. Since it requires approximately egg-shaped molds 19 and 19, and the desired shape can only be obtained by fitting these two molds together, the life of the molds is extremely short, making mass production difficult. was not suitable.

The present invention has been developed in view of the above-mentioned drawbacks, and the present invention will be described in detail below based on examples.

Fig. 3 is a perspective view with a partially broken surface showing an embodiment of the present invention, in which 1 is a substrate made of epoxy or the like, and on a predetermined printed pattern (not shown) on this substrate, one side is 0.4 mm. A light emitting diode 2 is mounted.

Reference numeral 3 denotes a reflective frame made of resin molding and having a height of 2 mm, and has seven reflective windows 4, 4, 4, 4, in the shape of a mouth.

These reflective windows 4, 4...4 have a surface with a width of 0.6 m.
It has a rectangular shape with a length of 3 mm, and a cylindrical shape with a diameter of 1 mm is arranged approximately in the center of a trapezoidal pyramid whose cross section becomes smaller toward the bottom, forming a through hole.

Reference numeral 5 denotes a mask plate laid on the surface of the reflective frame 3, which is made of a material that does not transmit light, such as a metal thin film, and is placed at a position corresponding to the reflective windows 4, 4...4. The strip-shaped through holes 6, 6...6 are provided.

Reference numeral 7 denotes an outer case made of transparent colored resin or the like, which encloses the substrate 1, the reflective frame 3, and the mask plate 5.

The present invention has the above-described structure, and since the bottom of the reflective window 4 is wide open, the light emitting diode 2 will not be damaged.

On the other hand, on the surface of the reflective window 4, the area directly above the light emitting diode 2 has a large amount of light, but since the opening area is larger than the area used for the surface, the light is diffused, and the area near both ends of the strip shape where the amount of light is small is as described above. Since the slope of the pyramid acts as a reflecting mirror and directs the light upward, a display with uniform brightness can be obtained as a whole.

Furthermore, since the mold for making the reflective window 4 has a cross-sectional area that decreases in one direction as shown in FIG. Since it is long enough, it is suitable for mass production.

In the above embodiment, the lower the height of the reflective frame 3 and the smaller the surface opening area of the reflective window 4, the greater the effect can be obtained.

For example, if the height of the reflective frame 3 exceeds 15 times the height of the light emitting diode 2 (for example, 4.5 mm or more when the height of the light emitting diode is Q, 3 mm), the height of the light emitting diode 2 is 4.5 mm or more. In this case, it is more effective to implement the reflective frame 13 by dividing it into two layers, upper and lower.

Furthermore, the surface opening of the reflective window 4 consists of a circle and a rectangular shape, but the area of the circle is preferably 9 times or less the surface area of the light emitting diode, and the width of the rectangular strip is 0.8 times the diameter of the circle.
This idea is most effective when the length is less than 4 times or less.

Furthermore, since the brightness is uniform on the surface of the reflective window 4, the through holes 6 of the mask plate 5 are not limited to the rectangular shape for displaying characters as shown in FIG. 5a, but are circular as shown in the same figure. You can.

Although the slope of the pyramid in the reflection window 4 is illustrated as a single slope, it may be a plurality of slopes as long as it functions as the above-mentioned reflecting mirror.

Furthermore, the above-mentioned combination of reflective windows is not limited to the shape of a square, and any combination of circular or substantially circular shapes is sufficient.Furthermore, the rectangular shape may also be rectangular, trapezoidal, etc. depending on the mutual relationship with adjacent reflective windows. It may have a sword point shape.

Further, the outer case can be replaced with tape or the like.

As described above, the present invention includes at least a substrate, a light emitting diode placed on the substrate, a reflective frame disposed on the substrate and having a reflective window surrounding the light emitting diode,
In a light emitting diode display device comprising a mask plate placed on the reflective frame, the bottom opening of the display window is approximately circular, and the surface opening is a strip having a width narrower than the diameter of the approximately circular shape. The mask plate has a shape in which the circular shape is arranged approximately in the center of the mask plate, and a through hole having the substantially circular shape or the rectangular shape is provided in the portion of the mask plate corresponding to the reflective window. , a small light emitting diode display with uniform brightness suitable for mass production can be obtained.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional light emitting diode display; Figure 2 is a perspective view of a conventional light emitting diode display;
FIG. 4 is a perspective view of a mold, FIG. 3 is a perspective view of a light emitting diode display according to an embodiment of the present invention, and FIG. 5 is a plan view of a mask plate. 1...Substrate, 2...Light emitting diode,
3... Reflective frame, 4... Reflective window, 5...
...Mask plate, 6...Through hole.

Claims (1)

[Scope of utility model registration request] At least a substrate, a light emitting diode placed on the substrate, a reflective frame disposed on the substrate and having a reflective window surrounding the light emitting diode, and a mask plate placed on the reflective frame. In the light emitting diode display device, the bottom opening of the display window has a substantially circular shape, and the surface opening has the substantially circular shape in the substantially central part of a rectangular shape having a width narrower than the diameter of the substantially circular shape. A light-emitting diode display device having a shape in which the mask plate has a substantially circular or rectangular through hole in a portion corresponding to the reflective window.