JPH0241661Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement in a dot matrix light-emitting display constructed using light-emitting elements such as light-emitting diodes.

PRIOR ART In recent years, so-called dots have been developed in which arbitrary characters, symbols, etc., can be displayed as dot patterns by energizing any of the light-emitting elements arranged in a matrix using a dynamic drive circuit. It has been proposed by the applicant as a matrix light emitting display. In such a light emitting display, a conductive pattern constituting a lighting circuit is formed, and a mask plate made of an insulating material is placed on a display substrate in which a large number of light emitting elements such as light emitting diodes are arranged in a matrix. It is located.

The structure of the mask plate 3 will be explained with reference to FIG. 3. This mask plate 3 has through holes forming through holes 31 at each portion corresponding to each of the light emitting elements 2, and the mask plate 3 is formed with through holes that form through holes 31 through adhesive or the like. After placing the mask plate 3 on the display substrate 1, the light emitting element 2 in which the transparent resin 4 is injected into the through hole 31 is sealed, and the sealing layer 4 is applied to each light emitting part A. Form. In this case, the upper surface of the sealing layer 4 is a flat surface, and a diffusing agent is mixed therein in order to improve the visibility (viewing angle, etc.) of the light emitting part A.

On the other hand, a predetermined conductive pattern 11 constituting a lighting circuit is formed in advance on the surface of the light emitter display substrate 1, and a lower electrode pattern 11c and a through hole 11d formed on the lower surface of the insulating plate 10 of the substrate 1 are formed in advance.
On the cathode side pattern portion 11a of the conductive pattern 11 connected through the conductive pattern 11, a large number of light emitting elements 2 made of semiconductor chips are arranged in a dot matrix shape and fixed with silver paste or the like.

The upper part of the light emitting element 2 is connected to the anode side pattern part 11b of the conductive pattern 11 via a bonding wire 21.

The mask plate 3 used in such a dot matrix light-emitting display prevents leakage of light emitted from the light-emitting element 2, enlarges the apparent diameter of the light-emitting part A, and makes its outline clear. It is used primarily to improve the visibility of the dot matrix light-emitting display, but at the same time protects the conductive pattern 11 appearing on the surface of the display substrate 1. It is also used to prevent leakage of the sealing resin 4 when sealing the light emitting element 2 (for example, when a thermosetting or ultraviolet curable liquid resin is used). .

Problems to be solved by the invention However, according to subsequent research by the present applicant, the sealing layer formed in the light emitting part to seal the light emitting element has a relatively high refractive index (1.3 or more). )
When filled with a light-transmitting material and having a concave upper surface and a light-reflecting surface formed on the inner circumferential wall of the transparent hole of the mask plate, the outline of the light-emitting part becomes clear, improving visibility. It turned out to be beneficial.

The present invention was developed based on this knowledge, and the outline of the light emitting part is clear, the apparent diameter of the light source can be increased, and the thickness of the mask plate can also be reduced, reducing material costs. The object of the present invention is to provide a dot matrix light-emitting display that can also be used to display images.

Specific Means to Solve the Problems In order to achieve the above objectives, the present invention forms a sealing layer for sealing the light emitting element of the light emitting part with a transparent material having a refractive index of 1.3 or more. The present invention provides a dot matrix light-emitting display body characterized in that the upper surface thereof is further formed into a concave surface, and a light reflecting surface is provided on the inner peripheral wall of the through-hole portion of the mask plate.

Embodiment of the invention An embodiment of the invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a dot matrix light-emitting display of the present invention.

Reference numeral 1 denotes a display substrate, on the upper and lower surfaces of which are provided conductive patterns 11 to form the aforementioned lighting circuit. Further, a mask plate 3 is bonded to the upper surface of the display substrate 1 with an adhesive or the like, and a transparent material is filled through each through hole 31 of the mask plate 3 so that each light emitting part A can emit light. Body element (semiconductor chip) 2
is sealed by a sealing layer 4.

The translucent material used here is not limited to resin materials such as epoxy resin, polycarbonate resin, and acrylic resin, but may also be inorganic glass.

FIG. 2 is a vertical cross-sectional structural diagram of the light emitting section A that constitutes the main part of the present invention.

The sealing layer 4 has a concave upper surface, and a light diffusing agent may be mixed therein if necessary.

The sealing layer 4 has a structure that sufficiently functions as a so-called concave lens. In this case, it is desirable to select the thickness of the sealing layer 4 (thin part at the center) to be about 1/2 to 2/3 of the thickness dM of the mask plate 3, and the thickness dM of the mask plate is the through-hole diameter R ( In other words, the optimum diameter is about 1/3 of the diameter of the light emitting dot, but it can be formed to about 1/5 to 1/2 times the diameter R of the through hole.

For example, when configuring the present invention using a dot matrix light-emitting display with a dot pitch (distance between adjacent light-emitting dots) of 8.0 mm, the dot diameter R is 6.5 mm, the thickness dM of the mask plate is 2.0 mm, and the display The thickness ds of the body substrate 1 can be formed to be about 1.6 mm.

The mask plate 3 is made of a flexible material such as neoprene rubber or silicone rubber in order to prevent the permeable material that forms the sealing layer from curing and shrinking during sealing and from warping or distortion due to temperature changes. It is desirable to do so.
Further, the light reflecting surface 5 formed on the inner circumferential wall of the through hole 31 of the mask plate 3 may be formed using a light reflective (for example, white color) material as it is, or the light reflecting surface 5 formed on the inner peripheral wall of the through hole 31
It is formed by applying a light-reflecting material such as silver paint to the inner circumferential wall of the Furthermore, it is preferable that the surface of the mask plate 3 be coated with a light-absorbing dark black coating so as not to reflect unnecessary light.

Display substrates to which the present invention can be applied are not limited to ordinary display substrates in which light-emitting elements are arranged in a matrix, but also display substrates in which a large number of so-called segment bodies in which light-emitting elements are arranged linearly on one common substrate are aligned. A composite substrate formed by arranging them as one composite substrate may also be used.

Further, a filter sheet (not shown) that absorbs light having a wavelength other than that emitted from the light emitting section A may be provided on the mask plate 3. All light other than the light wavelength emitted from part A is absorbed by the filter sheet, and only the light from light emitting part A stands out clearly, improving the visibility of the dot matrix light emitting display. There are advantages. Such an embodiment further improves the clarity of the light emitting section, especially when a light source for the light emitting section is used that generates monochromatic light, such as a light emitting diode.

Effects of the Invention The dot matrix light-emitting display of the invention has the following effects due to its structural features.

(1) Due to the synergistic effect of the concave lens effect of the sealing layer and the light reflecting surface formed on the inner circumferential wall of the through hole of the mask plate, the luminous flux from the light emitter element is concentrated on the outline of the light emitting part. Since the structure increases the luminous flux density, the outline of the light-emitting portion becomes clear, and an easy-to-see dot matrix light-emitting display can be obtained.

(2) Compared to the case where the upper surface of the sealing layer is flat or convex, the outline of the light emitting part is clearer, so the mask plate can be made thinner, the viewing angle can be increased, and material costs can be reduced. This can reduce manufacturing costs. Moreover, for this reason, when the same light-emitting element is used as a light source, a dot matrix light-emitting display with a thinner mask plate and a larger diameter of light-emitting dots can be obtained without impairing visibility.

Note that when a diffusing agent is not mixed when forming the sealing layer in the present invention, the synergistic effect of the concave lens effect as described above and the light reflecting surface formed on the inner circumferential wall of the through hole of the mask plate will occur. In addition, the light transmittance is increased (approximately 90% or more) compared to the one containing a diffusing agent, and a dot matrix light-emitting display with even higher brightness can be obtained.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing the first embodiment of the present invention, Fig. 2 is a vertical cross-sectional structural diagram of the light emitting part, and Fig. 3 is a vertical cross-sectional structural diagram of the light emitting part in a conventional dot matrix light emitting display. shows. In the figure, 1...display body substrate, 2...light emitter element, 3...mask plate, 31...through hole thereof, 4
. . . Translucent material forming the sealing layer, 5 . . . Light reflecting surface.

Claims (1)

[Scope of utility model registration request] In a dot matrix light-emitting display in which a mask plate having a through hole corresponding to each of the light emitting elements is disposed on a substrate on which light emitting elements are arranged, the distance is 1.3 or more from the through hole of the mask plate. A sealing layer is formed by filling a translucent material having a refractive index of A dot matrix light-emitting display.