JPH08160885A - Dot matrix light emitting display with light shielding louver - Google Patents

Abstract

PURPOSE: To provide a dot matrix light emitting display with a light shielding louver of high reliability which does not cause the mispositioning and lack of strength of the light shielding louver on the front surface of a display, has the good heat radiatability from the light shielding louver and has no possibility of the occurrence of the destruction and disconnection of light emitting elements by a difference in coefft. of thermal expansion and warpage, distortion, crack, peel, etc., of the light emitting display. CONSTITUTION: This dot matrix light emitting display is constituted by adhering a mask plate 2 longitudinally and transversely arranged and formed with many through-holes 21 on the front surface of a wiring board 1 longitudinally and transversely disposed with the many LED light emitting elements 5 and housing the respective light emitting elements 5 into the respective through-holes 21 to form many light emitting dots 4. The mask plate 2 is formed as a mask plate having a thickness of >=0.5mm formed of a rubber elastic material having a Young's modulus of <=500g/cm<2> and further, the light shielding louver 3 is formed by providing a back surface plate 32 longitudinally and transversely arranged and formed with many openings 31 with light shielding plates 33 between at least the top end edge and the upper and lower openings. The back surface plate 33 of the light shielding louver 3 is adhered to the front surface of the mask plate 2. Thermal stresses are absorbed by the mask plate 2 and the thermal conductivity from the mask plate 2 to the light shielding louver 3 is improved by adhesion of the back surface plate 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dot matrix light emitting display with a light-shielding louver, which has improved visibility, heat dissipation, warpage, distortion and the like.

[0002]

2. Description of the Related Art Various types of dot-matrix light-emitting displays have been developed so far, and the applicant of the present invention has developed a large number of L
A mask plate having a large number of through holes arrayed vertically and horizontally is adhered to the front surface of a wiring board in which ED light emitting elements are arranged vertically and horizontally, and a large number of light emitting dots are formed by accommodating each LED light emitting element in each hole. We have already developed a dot matrix light emitting display.

This dot-matrix light-emitting display has the advantage of good visibility because it has a large apparent light-emitting dot despite the use of a small LED light-emitting element, but it can be used outdoors in bright places. In the case of use, it is necessary to attach a light-shielding louver made of a metal plate or the like to the front surface of the light emitting display to shield the direct sunlight so that the visibility is not impaired.

[0004]

However, when the light-shielding louver made of a metal plate or the like is attached to the front surface of the light-emitting display body with an adhesive, the internal stress due to the temperature environment change due to the difference in thermal expansion coefficient between the two. Occurs, which may cause breakage or disconnection of the light emitting element, and easily cause warping, distortion, cracks, peeling, etc.So far, it was decided to attach the four corners of the light shielding louver with screws etc. A large loose hole or the like can absorb the difference in thermal expansion and contraction, which causes a problem that the light shielding louver is easily displaced.

When the light-shielding louver is attached with screws or the like as described above, the light-shielding louver itself must have a certain level of strength, but if the light-emitting display has a small dot size, the thickness of the light-shielding louver is small. I have no choice but to thin
There is also a problem that the strength and mounting strength of the light shielding louver itself are insufficient.

Further, if the light-shielding louver is attached with a screw or the like,
Since the light-emitting display and the light-shielding louver do not come into close contact with each other, the thermal conductivity is poor, and therefore, there is a problem that the heat generated from the LED light-emitting element is difficult to be radiated through the light-shielding louver.

The present invention has been made in view of the above problems, and it is an object of the present invention to prevent displacement of the light-shielding louver and lack of strength and to provide good heat dissipation from the light-shielding louver. It is an object of the present invention to provide a highly reliable dot matrix light emitting display with a light-shielding louver, which is free from the risk of destruction or disconnection of a light emitting element and warpage, distortion, cracking, peeling or the like of a light emitting display due to a difference in thermal expansion coefficient.

[0008]

In order to achieve the above object, a dot matrix light emitting display with a light-shielding louver according to the present invention has a large number of through holes on the front surface of a wiring board in which a large number of LED light emitting elements are vertically and horizontally arranged. In a dot-matrix light emitting display in which a mask plate in which the LEDs are arranged vertically and horizontally is adhered and each LED light emitting element is accommodated in each through hole to form a large number of light emitting dots, the mask plate has a Young's modulus of 500 g / mm ² A mask plate having a thickness of 0.5 mm or more formed of the following rubber elastic body is used. Further, a light-shielding plate is provided between at least the upper edge and the upper and lower openings of the back plate having a large number of openings arranged vertically and horizontally to form a light-shielding louver. It is characterized in that the back plate of the light-shielding louver is adhered to the front surface of the mask plate.

Preferably, the opening diameter R of the through hole on the front surface of the mask plate and the thickness T of the mask plate are R / 5≤T≤3.
The thickness of the mask plate T
Is set in the range of 0.5 to 3.0 mm.

[0010]

According to the present invention, the mask plate adhered to the front surface of the wiring board is made of a rubber elastic body having a Young's modulus of 500 g / mm ² or less and has a thickness of 0.5 mm or more. If you attach the back plate of the shading louver to the front of the
Since the mask plate absorbs and relaxes the stress due to the thermal expansion and contraction of the wiring board and the back plate, even if both are bonded,
No warp, distortion, crack, peeling, etc. will occur.

Moreover, since the back plate of the light-shielding louver, the mask plate, and the wiring board are adhered to each other and have good thermal conductivity, the heat generated by the LED light-emitting elements of the wiring board is conducted to the back plate of the mask plate and the light-shielding louver. Then, heat is efficiently radiated from each light shielding plate of the light shielding louver, which also functions as a radiation fin, to the outside air, and the temperature rise is suppressed to a low level.

Further, since the back plate of the light-shielding louver is bonded to the mask plate and integrated with the mask plate, the strength of the light-shielding louver is sufficiently secured even if the back plate or the light-shielding plate of the light-shielding louver is thin. .

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view showing an embodiment of a dot matrix light emitting display with a light-shielding louver according to the present invention, FIG. 2 is a partially enlarged vertical sectional view of the same embodiment, and FIG. 3 is a front view of the same embodiment. 4 is a partial sectional view of the mask plate.

This light-emitting display with a light-shielding louver has a wiring board 1, a mask plate 2 and a light-shielding louver 3 bonded and integrated, and shows an embodiment in which 16 × 16 light emitting dots 4 are formed vertically and horizontally. That is, in this light-emitting display body with a light-shielding louver, a mask plate 2 having 16 × 16 through holes 21 formed vertically and horizontally is bonded to the front surface of a wiring board 1 in which 16 × 16 LED light-emitting elements 5 are arranged vertically and horizontally. , Each of the LED light emitting elements 5 is housed in each through hole 21 to form 16 × 16 light emitting dots 4 vertically and horizontally, and the back plate 32 of the light shielding louver 3 having 16 × 16 openings 31 vertically and horizontally is masked. It is bonded to the front surface of the plate 2.

The wiring board 1 has 16 vertical conductive patterns (for example, a cathode side Y pattern group) formed by etching or the like on the front surface of a copper clad laminate or a ceramic substrate using glass epoxy resin as a base material. Simultaneously, 16 horizontal conductive patterns (for example, a group of X patterns on the anode side) are formed on the back surface in the same manner. As shown in FIG. It is led out to the front surface of the wiring board 1 for each. Then, the LED light emitting element 5 is fixed on the lead-out portion with a conductive paste such as silver paste, and is connected to the conductive pattern 11a on the surface of the substrate with the bonding wire 6 to form an XY matrix lighting control circuit. . Further, on the back surface of the wiring board 1, the leads 7 of the conductive patterns 11a and 11b are provided in a protruding manner.

The mask plate 2 adhered to the front surface of the wiring board 1 must be made of a rubber elastic body having a Young's modulus (elastic modulus) of 500 g / mm ² or less, and its thickness is at least 0. 0.5 mm or more (preferably 0.8 m
m or more). When the mask plate 2 is made of a so-called high-rigidity material having a Young's modulus of more than 500 g / mm ² or a mask plate having a thickness of less than 0.5 mm is used, the wiring substrate 1, the mask plate 2 and the light shielding louver back plate 32 are respectively formed. When the materials have different thermal expansion coefficients, the mask plate 2 does not sufficiently absorb and relax the thermal stress caused by the change in the temperature environment, so that the warp, the strain, the crack, and the peeling are likely to occur. It becomes difficult to achieve the object of the invention. Specific examples of the rubber elastic body having a low Young's modulus as described above include silicone rubber, neoprene rubber, urethane rubber and the like. Among them, silicone rubber is excellent in heat resistance and weather resistance, and Young's modulus changes with time. It is particularly preferably used because it has a small amount.

The through holes 21 of the mask plate 2 make the light emitting dots 4 look wide and efficiently reflect and emit the light from the light emitting element 5 to the front surface, so that the front widening as shown in FIGS. It is formed in a mortar shape, and its inner peripheral surface is a white or silver-based light reflecting surface. Then, the translucent sealing material 8 is filled and cured in the through hole 21, and L in the through hole is filled.
The mounting portion and the wire bonding portion of the ED light emitting element 5 are sealed so as not to be corroded by an external gas, moisture or the like. As with the mask plate 2, silicone rubber is suitable for the sealing material 8.

As shown in FIG. 4, the opening diameter of the through hole 21 on the front surface of the mask plate 2 (in the case of a square opening, the opposite side length) R
And the thickness T of the mask plate 2 are set such that R / 5 ≦ T ≦ 3R and the thickness T of the mask plate 2 is 0.5 to 0.5.
It is desirable to set it in the range of 3.0 mm. When the thickness T of the mask plate 2 is set to less than 1/5 of the opening diameter R of the through hole 21, the thickness of the mask plate 2 is 0.5 mm especially in the case of a small-sized light emitting display having a small opening diameter R. If it is less than the above, there is a possibility that the above-mentioned stress absorption and relaxation will be insufficient, and since the through hole 21 is shallow and has a flat mortar shape, the sealing material 8 for the light-emitting dots 4 is used. LE
There is also a possibility that inconvenience such as insufficient sealing of the D light emitting element 5 may occur. On the other hand, the thickness T of the mask plate 2 is set to the through hole 2
If it is set to be larger than 3 times the opening diameter R of 1 and exceeds 3.0 mm, the visibility of the light emitting dots 4 is reduced, the amount of rubber elastic material used is increased, and the total thickness of the light emitting display body is increased. It only causes inconveniences such as larger size,
There is almost no additional merit in terms of stress absorption and relaxation, sealing property, and the like.

For reference, 40 mm square, 64 mm square, and 96 mm suitable for the present invention having 16 × 16 luminescent dots
Table 1 below shows specific numerical values of the preferable thickness T of the mask plate and the opening diameter R of the through hole for each of the square, 128 mm square, and 192 mm square light emitting display bodies.

[Table 1]

A light-shielding louver 3 adhered to the front surface of the mask plate 2.
Is made of a metal such as aluminum or a heat resistant plastic such as polycarbonate or Noryl resin, and 16 × 16 openings 31 are formed in an array on the back plate 32 in correspondence with the through holes 21 of the mask plate 2. A light shielding plate 33 is provided between the upper edge of the back plate 32 and the upper and lower openings. The entire surface is made of a black light absorbing surface to improve the display contrast and prevent the visibility from being impaired by the reflection of light. In this case, the light-shielding louver 3 may be composed of a plurality of structures, such as four side-by-side structures of 8 × 8 dot structure, instead of the 16 × 16 dot integrated structure of this embodiment. It goes without saying that, on the contrary, one light-shielding louver 3 may be constituted by a plurality of wiring boards 1 and a plurality of mask plates 2 to form an integrated light emitting display. Further, in this embodiment, the through holes 21 of the mask plate 2 and the openings 31 of the back plate 32 of the light-shielding louver 3 are arranged in a 1: 1 correspondence, but a plurality of mask plates 2 (for example, 4) through hole 2
One opening 31 of the light-shielding louver 3 may be arranged so as to correspond to 1, and it can be applied to a relatively large size having a large dot size.

The thickness of the back plate 32 and the light blocking plate 33 of the light blocking louver 3 is preferably 0.5 mm or less for a light emitting display body having a small dot size with a light emitting dot pitch of 4 mm or less. However, sufficient practical strength can be obtained by integrally bonding with the mask plate 2.
It is desirable to set the protruding length of the light shielding plate 33 to be approximately the same as the mutual distance between the light shielding plates. If the protruding length of the light blocking plate 3 is longer than the mutual distance between the light blocking plates, the light blocking plate 3 becomes an obstacle when looking up the light emitting display from an obliquely lower position,
On the other hand, if the protruding length of the light shielding plate 3 is too short, absorption and blocking of direct sunlight from above will be insufficient, so
In either case, it becomes difficult to satisfactorily improve the visibility. The light shield plate 33 may be provided with a slight slanting inclination.

As an adhesive agent for adhering the wiring board 1, the mask plate 2, and the light-shielding louver 3 to each other, a silicone rubber adhesive or an epoxy resin adhesive is used. In particular, the mask plate 2 is made of silicone rubber. In that case, a silicone rubber-based adhesive is preferably used.

When the light-shielding louver 3 as described above is adhered to the front surface of the mask plate 2, direct sunlight from above is absorbed and blocked by the light-shielding plate 33 of the light-shielding louver 3, so that the display relative brightness of the light emitting display body is increased. The visibility is significantly improved by increasing the display contrast. Moreover, since the heat conductivity from the mask plate 2 to the light-shielding louver 3 is improved by the adhesion, the heat generated in the LED light-emitting element 5 of the wiring board 1 is applied to the mask plate 2 and the back plate 32 of the light-shielding louver 3.
Each light-shielding plate 3 that conducts heat and functions as a radiation fin.
Heat is efficiently radiated from 3 to the outside air. Especially, the light-shielding louver 3
Is optimally formed of a metal material such as aluminum having good thermal conductivity. Therefore, a more reliable light-emitting display body in which the number of LED light-emitting elements 5 provided is increased to provide a high-luminance light-emitting display, or the number of LED light-emitting elements 5 provided is kept unchanged to suppress a temperature rise. Can be
Further, as described above, the stress caused by the thermal expansion / contraction difference among the wiring board 1, the mask plate 2, and the light-shielding louver 3 has a Young's modulus of 500 g / mm ² or less and a thickness of 0. Since it is sufficiently absorbed and relaxed by the mask plate 2 having a size of 5 mm or more, the LED light emitting element is not damaged or broken, and the display body is not warped, distorted, cracked, peeled, or the like even when the three are bonded. Since, of course, the light-shielding louver is not displaced as in the case of the conventional screw fastening, the reliability can be greatly improved also in these points.

Although the present invention has been described above with reference to the embodiment of the light emitting display having 16 × 16 light emitting dots, the present invention is not limited to this embodiment, and 8 × 8 light emitting dots are used. A light emitting display which has, a light emitting display having 24 × 24 light emitting dots, and a light emitting dot which is a rectangle instead of a circle, and each light emitting dot has one LED light emitting element of blue, red and green. Or, it is applied to various light emitting display bodies such as a full-color light emitting display body in which a plurality of light emitting display bodies are arranged.

[0026]

As is apparent from the above description, the dot matrix light emitting display with a light-shielding louver of the present invention has good visibility even when installed in a bright environment such as outdoors, because of the light-shielding louver. Since the heat dissipation through the louver is good, the number of LED light-emitting elements provided is increased to provide a high-luminance light-emitting display body, or the number of LED light-emitting elements provided is kept as it is and the temperature rise is kept low to achieve high reliability. It can be used as a light emitting display, and the stress caused by the difference in thermal expansion and contraction between the wiring board and the light-shielding louver is sufficiently absorbed and relaxed by the mask plate. As a result, the light-shielding louver is not displaced as in the case of the conventional screw fixing, and even if the light-shielding louver is thinned, it is filled with the mask plate by adhesion. Since Do practical strength is obtained, exhibits particularly such thickness as possible preferably applied to a small light-emitting display of sufficiently take no emission dot size, various remarkable effects.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a dot matrix light emitting display with a light-shielding louver according to the present invention.

FIG. 2 is a partially enlarged vertical sectional view of the embodiment.

FIG. 3 is a front view of the embodiment.

FIG. 4 is a partial cross-sectional view of a mask plate.

[Explanation of symbols]

 1 wiring board 2 mask plate 21 through hole 3 light-shielding louver 31 opening 32 back plate 33 light-shielding plate 4 light-emitting dot 5 LED light-emitting element R through-hole opening diameter T mask plate thickness

Claims (2)

[Claims] 1. A mask plate having a large number of through holes arranged vertically and horizontally is adhered to a front surface of a wiring board in which a large number of LED light emitting elements are arranged vertically and horizontally, and each LED light emitting element is housed in each through hole. In a dot matrix light emitting display in which a large number of light emitting dots are formed by using the mask plate, the Young's modulus is 500 g / mm.
A mask plate made of rubber elastic body of ² or less and having a thickness of 0.5 mm or more. Further, a light-shielding louver is provided by providing a light-shielding plate between at least the upper edge and the upper and lower edges of the rear plate having a large number of openings arranged vertically and horizontally. And a back plate of the light-shielding louver is adhered to the front surface of the mask plate. 2. The opening diameter R of the through hole on the front surface of the mask plate and the thickness T of the mask plate have a relationship of R / 5 ≦ T ≦ 3R, and the thickness T of the mask plate is 0.5 to 3. The dot matrix light emitting display with a light-shielding louver according to claim 1, which is 0 mm.