JPS5941192B2 - Manufacturing method of light emitting diode day indicator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a light emitting diode type day of the week display, and more particularly to a method of manufacturing a light emitting diode type day of the week display that is compact and capable of providing high quality display.

Conventionally, a light emitting diode as shown in FIG.
21, days of the week 122, 122, etc., as shown in FIG. A plate 109 was placed on it, and these were covered with an outer case 113.

In order to obtain a display with uniform brightness on the display surface, a light diffusing sheet 106 of milky white color or the like is used to clarify the outline of the display, or when it is desired to display characters with a single light emitting diode (for example, the days of the week in the figure). (display), a mask plate 109 was used to form a transparent portion in the shape of the character. The outer case 113 not only has the role of making the display surface look flat and improving the contrast of the display, but also has the role of aligning the mask plate. That is, the mask plate 109 described above
If the transparent hole (not shown) does not correspond to the position of the reflective window 105 provided in the reflective frame 103, the outline of the display will be blurred or the characters will be displayed with missing characters. be. However, if the outer case 113 is required, the display becomes larger and the manufacturing cost increases. In addition, in order to make the display smaller, there is a method of eliminating the outer case and pasting a printed light diffusion sheet on the surface of the reflective frame. When displaying English or Japanese characters on each of a series of many display elements, the position of the characters obtained by printing etc. and the position of the reflective window tend to shift during the work of pasting the light diffusion sheet, which is extremely inconvenient. There is also a method of devising the shape of the reflective frame and eliminating the mask by printing, etc., but the reflective frame is expensive and the light diffusion sheet is thin, so the unevenness of the reflective frame surface appears on the display surface and the quality of the display is low. Become. Another disadvantage of conventional displays such as that of FIG. 1a is that the day of the week display is difficult to read.

On days of the week 122, 122..., the display element corresponding to the day of the week out of the seven display elements corresponding to Saturday is lit, and the size of this display element is determined by the light emission intensity of the light emitting diode that is the light source. For example, one display element (one layer or one segment) incorporates one Gap red light emitting diode, and the time 120, 120, etc. Character height is 15
When mm to 25mwL, day of the week 122, 122...
The display elements of ... are SU in a 3n to 7n square frame.
The characters N, MON, . . . or sleep moon, . . . will be drawn. Therefore, if a decorative clock or the like is made using such a display, the characters on the day of the week display will become difficult to read even from a distance of 2 to 3 meters, making it impossible to determine which day of the week it is. The present invention has been made to improve the above-mentioned two drawbacks, and will be described in detail below.

FIG. 2 is a perspective view of a display manufactured by the method of the present invention, and FIGS. 3A to 3D are side views centering on the day of the week display section showing the manufacturing method of the present invention in this order. (Figure 3a
) First, light emitting diodes 2, 2, etc. such as Gap are placed on a board 1 on which printed wiring such as paper epoxy is applied.
... and wire it, and attach the reflective frame 3, such as a resin molded product, to the board 1.
Fixed to.

If a lead frame or the like is used as the substrate 1, the substrate 1 may be fixed to the reflective frame 3. The reflective frame 3 has a reflective window 5 surrounding the light emitting diodes 2, 2... to form seven display elements 4, 4... corresponding to the seven days of the year.
, 5... are provided. (FIG. 3b) Next, a light diffusion sheet 6 is attached to the surface of this reflective frame 3 with an adhesive 7.

Titanium oxide (TiO.TiO2), calcium oxide (CaO), or the like as a light diffusing agent is mixed with a coloring agent into the light diffusing sheet 6 or adhesive 7 made of polyester film or the like to obtain a colored transparent or colored opaque appearance. . The thickness of the light diffusion sheet 6 is 100 μm to 300 μm,
Because it can be made thinner for the black matte paint described later, 2
10μm or less and the light transmittance is 8 before adding the light diffusing agent.
Most preferably, it is 0% or more. The coloring agent preferably exhibits a dark color close to the color of light emitted by the light emitting diodes 2, 2, . (FIG. 3c) A black matte paint 9 is applied to the surface of the light diffusing sheet 6 by screen printing or the like using one end face (for example, 8) of the reflective frame 3 as a reference.

The paint 9 has a high affinity with the light diffusion sheet 6, does not apply stress to the light diffusion sheet 6 during curing, has appropriate strength or viscosity after curing, and should not fade or discolor the light diffusion sheet 6. For example, it is best to mix black pigment (e.g. Carbon Black, Eye Poly Black) into acrylic resin paint (e.g. Zentex (trademark)) and print it to a thickness of 20 to 60 ttm. Shows favorable properties. In this printing application, cut out characters 10 and 10 are made as shown in a and b in Fig. 4,
This serves as a conventional mask plate. Since the printing coating is based on the end surface of the reflective frame 3, the cutout characters 10
, 10 and the display elements 4, 4, . . . will not be misaligned. (Fig. 3 d) Finally, on the surface of the black matte paint 9, again using the end surface 8 of the reflective frame 3 as a reference, white paint is applied. . . . Print partitions 12, 12 . . . between them. Partition 12,1
A frame may be used instead of 2. Also this partition 12
, 12...Also, the area where the frame is printed may be removed when printing the black matte paint 9, but in this case, the white paint will be in direct contact with the light diffusion sheet 6, so there will be no color transfer. It is necessary to consider the material of the white paint. As described above, the display device manufactured by the manufacturing method of the present invention can be made small, and the unevenness on the surface of the reflective frame is flattened or made less noticeable to some extent by applying black matte paint, so that, for example, red letters are printed on a black background. It is possible to produce an elegant display that stands out, and it can be easily manufactured without positional deviation, especially in a display device that displays the day of the week using seven display elements.
Even in environments where text is difficult to read, the white partitions or frames make it easy to read the day of the week from the lighting position.

[Brief explanation of the drawing]

Figure 1 is a perspective view a and a sectional view b1 of the main part of the display unit.
The figure is a perspective view of a display device according to the present invention, FIG.
The figure is a plan view of main parts showing an example of cutout character printing. 1...Substrate, 2,2...Light emitting diode, 3...Reflection frame, 4,4...Display element, 6... Light diffusion sheet, 9...Black matte paint, 10,10...Cut out letters, 12
, 12... Partition.

Claims (1)

[Claims] 1 Surround the light-emitting diode with a reflective frame to mark 7, which corresponds to the Seven Days of the Seven Days.
A colored light diffusion sheet is pasted on the surface of the reflective frame, characters are printed with black gloss paint on the surface of the light diffusion sheet using the end surface of the reflective frame as a reference, and the same is applied. A method for manufacturing a light-emitting diode day of the week display, characterized in that symbols for separating the display elements are printed with white paint on the end surface of the reflective frame.