JPH0850458A - Light emitting display device - Google Patents

Abstract

PURPOSE:To improve heat radiation efficiency by packaging light emitting elements on one surface side of a printed circuit board and driving elements on the other surface side, arranging lead wires of these light emitting elements so as to avert the driving elements and tightly adhering a heat radiatable sheet and a heat radiating member. CONSTITUTION:LED lamps 200 as the light emitting elements are packaged on one surface side 110 of the printed circuit board 100 and the driving elements 300 of a front surface packaging type for driving these LED lamps 200 are packaged on the other surface side 120. The LED lamps 200 consist of sets of the lamps emitting red light, green light and blue light and are arranged in a matrix form. The lead wires of the LED lamps 200 are bent and formed in an approximate crank form and are arranged to avert the driving elements 300 packaged on the other surface side 120 of the printed circuit board 100. The heat radiatable sheet 400 is tightly adhered to the other surface side 120 of the printed circuit board 100. The heat radiating member 500 consisting of a frame part 510 housing the printed circuit board 100 and plural fin parts 520 projecting to the rear surface side of the frame part 510 is tightly adhered to the heat radiatable sheet 400.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to light emitting display devices.

[0002]

2. Description of the Related Art A conventional light emitting display device of this type will be described with reference to FIG. The light-emitting display device illustrated in FIG. 8A includes a mother board 900, a plurality of sub-boards 910 that are orthogonally attached to the mother board 900 via connectors 930, and light-emitting elements mounted on the sub-board 910. Multiple LEs
It has a D lamp 940 and a driving element 950 mounted on the sub board 910. In such a light emitting display device, the LED lamps 940 are arranged in a matrix when facing the front side, that is, the LED lamps 940.

Further, the light emitting display device shown in FIG. 8B does not have the sub-board 910, and a plurality of LED lamps 94 which are light emitting elements directly on the mother board 900.
0 is implemented. In addition, a driving element 950 for driving the LED lamp 940 is provided on the back surface side of the mother board 900.
Has also been implemented.

[0004]

However, in the conventional light emitting display device described above, if the cooling air can be passed between the sub-boards 910 as shown in FIG. 8A, the light emitting display device can be used. The thickness of the entire device tends to be large. Further, in the case of the one shown in FIG. 8B, the thickness dimension does not become large, but it is difficult for the cooling air to pass therethrough and the heat radiation efficiency is not good. In particular, a full-color type light emitting display device, which consumes much more power, cannot be used due to its low heat dissipation effect.

In the type shown in FIG. 8B, LE
In order to avoid the lead wire 941 of the D lamp 940, the driving element 950 is mounted so as to float from the motherboard 900. Therefore, for example, even if a heat dissipation sheet having excellent thermal conductivity is attached to the back surface side of the mother board 900, it is difficult to efficiently dissipate heat from all the LED lamps 940.

In addition, in order to display characters and figures, LED
In the matrix type in which the lamps are arranged in a matrix, it is difficult to efficiently dissipate the heat generated by the inner LED lamp.

The present invention has been made in view of the above circumstances, and provides a light emitting display device which is excellent in heat dissipation efficiency and does not have a large thickness, and is particularly suitable for a full color type or a matrix type light emitting display device. It is an object.

[0008]

A light emitting display device according to the present invention includes a printed circuit board on which a light emitting element is mounted on one side and a surface mount type driving element for driving the light emitting element is mounted on the other side. The printed circuit board is provided with a heat dissipation sheet that is in close contact with the other surface side and a heat dissipation member that is in close contact with the heat dissipation sheet, and the lead wire of the light emitting element is arranged so as to avoid the drive element.

Further, the heat dissipation member has a frame body portion for accommodating the printed circuit board and the heat dissipation sheet, and a fin portion protruding from the back surface side of the frame body portion.

As the light emitting element, two or three types which emit different colors are used.

Further, the light emitting elements are arranged in a matrix.

[0012]

1 is a schematic sectional view of a light emitting display device according to an embodiment of the present invention, FIG. 2 is a schematic side view of an LED lamp used in the light emitting display device, and FIG. 1 is a drawing of a printed circuit board used, in which an LED lamp mounted on one surface side and a driving element mounted on the other surface side are shown in an overlapping manner.

FIG. 4 is an enlarged schematic plan view of a printed circuit board used in this light emitting display device, and FIG. 5 is a drawing of a heat dissipation member used in this light emitting display device. FIG. FIG. 6A is a plan view, FIG. 6B is a schematic front view, FIG. 6C is a schematic side view, and FIG. 6 is a drawing of a louver used in this light emitting display device. A plan view, FIG. 7B is a schematic side view, and FIG. 7 is a drawing of a spacer used in this light emitting display device. FIG. 7A is a schematic plan view and FIG. 7B is a schematic view. It is a side view.

The light emitting display device according to this embodiment is
LED lamp 200 as a light emitting element on one surface side 110
However, a printed circuit board 100 having surface-mounted drive elements 300 for driving the LED lamps 200 mounted on the other surface side 120, and the other surface side 1 of the printed circuit board 100.
The LED lamp 200 includes a heat dissipation sheet 400 that is in close contact with the heat dissipation sheet 400 and a heat dissipation member 500 that is in intimate contact with the heat dissipation sheet 400. The lead wire 210 of the LED lamp 200 is arranged so as to avoid the driving element 300.

The LED lamps 200 are a set of four. That is, one set that emits red light, two sets that emit green light, and one set that emits blue light form one set. The LED lamp 200 has a length of 16
A total of 256 sets of 16 sets and 1024 sets are mounted on one printed circuit board 100. It should be noted that in FIG. 3, for convenience of drawing, only the LED lamp 200 in the lower left corner portion is drawn, and in other portions, the LED lamp 200 is represented by a simple square.

The lead wire 21 of the LED 200 is also used.
0 is bent and formed in a substantially crank shape as shown in FIG. This is to avoid the drive element 300 mounted on the other surface 120 of the printed circuit board 100 when mounted on the printed circuit board 100.

In the LED lamp 200, the height dimension of the light emitting portion 220 varies depending on the type, so that the lead wire 21
This is also because the heights of the light emitting portions 220 of all the LED lamps 200 are made uniform by forming 0 in a substantially crank shape.

The printed circuit board 100 on which the LED lamps 200 are mounted has 1024 LED lamps 200.
A total of 2048 lead holes 130 for mounting are mounted.

On the other hand, the other side 120 of the printed circuit board 100
A wiring pattern 150 for the driving element 300 is formed on the substrate (see FIG. 4). This wiring pattern 150
Is, of course, set so as not to interfere with the lead hole 130.

The driving element 300 is, as shown in FIG.
Between the third and third rows, between the fourth and fifth rows, between the sixth and seventh rows, between the tenth and eleventh rows, twelfth and thirteenth rows , And between the 14th and 15th rows.

Further, the printed circuit board 100 is shown in FIG.
As shown in FIG. 8, a total of eight mounting holes 140 are opened. The mounting hole 140 is for mounting the printed circuit board 100 on the heat dissipation member 500 by using a spacer 600 described later. As shown in FIG. 4, the lead hole 130 formed around the mounting hole 140 is attached to the mounting hole 14 as shown in FIG.
It is open toward 0.

The heat dissipating sheet 300 is a sheet-shaped member having silicon as a main component and having a high thermal conductivity, and has a certain degree of flexibility. That is, it is required that the other surface side 120 of the printed circuit board 100 and the drive element 300 mounted on the printed circuit board 100 are in close contact with each other, and the surface not in close contact with these is substantially smooth. The heat dissipation sheet 300 is used after being cut into the shape of the printed circuit board 100.

The heat dissipation sheet 300 has through holes 310 through which the board mounting screws 810 for mounting the printed circuit board 100 on the heat dissipation member 500 are formed in the same pattern as the board mounting holes 530. There is.

The heat dissipating member 500 is made of aluminum having excellent heat dissipating properties. As shown in FIG.
It is composed of a substantially thin dish-shaped frame body portion 510 in which 0 is stored, and a plurality of fin portions 520 projectingly provided on the back surface side of the frame body portion 510.

The frame body 510 has the heat radiating sheet 400 adhered to the other surface 120 of the printed circuit board 100.
Is stored, the depth is set such that the light emitting portion 220 of the LED lamp 200 slightly protrudes from the edge portion of the frame body portion 510.

Further, the frame portion 510 is provided with eight board mounting holes 530 for mounting the printed circuit board 100 to the heat dissipation member 500 (see FIG. 5A).
The board mounting holes 530 are formed in the same pattern as the mounting holes 140 of the printed circuit board 100.

On the other hand, the fin portion 520 is formed in a substantially thin trapezoidal shape as shown in FIG. 5C and the like, and has a predetermined interval, that is, the rear surface side of the frame body portion 510, that is, the printed circuit board 100. It is projected on the side opposite to the side where the etc. are stored. The fin portion 520 dissipates the heat of the LED lamp 200 and the like.

A louver 700 having a plurality of lateral eaves 710 is attached to such a light emitting display device. As shown in FIG. 6, this louver 700 is configured by combining 17 vertical bars 720 with a total of 16 eaves 710 provided in the lateral direction. Then, the eaves 710 and the vertical bars 720 form 16 × 16 pieces,
A total of 256 cells are formed. Four LED lamps 200, that is, one set of LED lamps 200, are fitted in one cell.

The eaves portion 710 is for preventing the light from above from directly illuminating the LED lamp 200. Due to the eaves portion 710, the LED
The display by the lamp 200 can be clearly seen. In addition, it is possible to prevent the deterioration of the LED lamp 200 due to the light from above, particularly, the sunlight when used outdoors.

Further, the louver 700 is provided with four mounting holes 730. This mounting hole 730 is
This is for attaching the louver 700 to the heat dissipation member 500 by a spacer 600 described later.

As shown in FIG. 7, the spacer 600 for mounting the printed circuit board 100 on the heat dissipation member 500 is formed in a square shape on the upper surface side and a truncated cone shape on the lower surface side. Louver screw holes 610 are provided from the upper surface side, and substrate screw holes 620 are provided from the lower surface side. Both screw holes 610 and 620 do not penetrate. Further, a groove 630 is provided on the upper surface side.

The groove 630 is a portion into which the tip of a flat-blade screwdriver is fitted. That is, the board mounting screw 810 is screwed in when assembling the light emitting display device.
This is to prevent the spacer 600 from rotating at this time.

In the drawing, reference numeral 830 denotes a molding resin, which fills a gap between the printed circuit board 100 and the light emitting portion 220 of the LED lamp 200, and is a spacer 6
The upper surface of 00 is flush with the molding resin 830, and the upper surface of the molding resin 830 is flush with the edge of the frame body 510.

Although the LED lamp 200 is used as the light emitting element in the above-described embodiment, the present invention is not limited to this. It may be another light emitting element such as an incandescent lamp. However, since the LED lamp 200 generates less heat than other light emitting elements, it is suitable as a light emitting display device.

The LED lamp 200 has a red light,
Although the ones that emit green light and blue light have been described, two types may be used, such as one that emits red light and the one that emits green light.

[0036]

The light emitting display device according to the present invention is
A printed circuit board on which a light emitting element is mounted on one surface side and a surface mount type driving element for driving the light emitting element on the other surface side, a heat dissipation sheet adhered to the other surface side of the printed circuit board, and this heat dissipation And a heat dissipation member that is in close contact with the conductive sheet, and the lead wire of the light emitting element is arranged so as to avoid the drive element. For this reason, the heat radiation sheet can be brought into close contact with the printed circuit board and the drive element, and moreover, the heat radiation sheet is brought into close contact with the heat radiation member.
The heat generated from the D lamp and the driving element is efficiently transmitted to the heat dissipation member and is dissipated into the atmosphere from the heat dissipation member. Therefore, it is suitable for a full-color type light emitting display device which consumes a large amount of power and generates a large amount of heat.

The heat dissipating member has a frame body portion for accommodating the printed circuit board and the heat dissipating sheet, and a fin portion projecting from the back surface side of the frame body portion. Therefore, higher cooling efficiency can be obtained by passing the cooling air through the fins.

The light emitting element can be a full color type light emitting display device as long as it emits red, green and blue light. As described above, since this light emitting display device can obtain high heat dissipation efficiency, it is most suitable for a full-color type light emitting display device.

Furthermore, since the light emitting elements are arranged in a matrix, it is possible to display arbitrary characters and figures. When the light emitting elements are arranged in a matrix, heat treatment from the inner light emitting elements becomes a problem, but since the heat is also transmitted to the heat dissipation member via the heat dissipation sheet, more light is emitted. It is suitable for a matrix type light emitting display device having an element.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a light emitting display device according to an embodiment of the present invention.

FIG. 2 LED used in this light emitting display device
It is a schematic side view of a lamp.

FIG. 3 is a drawing of a printed circuit board used in this light emitting display device, in which an LED lamp mounted on one surface side and a driving element mounted on the other surface side are shown in an overlapping manner.

FIG. 4 is an enlarged schematic plan view of a printed circuit board used in this light emitting display device.

5A and 5B are drawings of a heat dissipation member used in this light emitting display device, wherein FIG. 5A is a schematic plan view, FIG. 5B is a schematic front view, and FIG. It is a figure.

6A and 6B are drawings of a louver used in this light emitting display device, wherein FIG. 6A is a schematic plan view and FIG. 6B is a schematic side view.

7A and 7B are drawings of a spacer used in this light emitting display device, wherein FIG. 7A is a schematic plan view and FIG. 7B is a schematic side view.

FIG. 8 is a schematic configuration diagram of a conventional light emitting display device.

[Explanation of symbols]

 100 Printed Circuit Board 110 One Side of Printed Circuit Board 120 Other Side of Printed Circuit Board 200 LED Lamp 300 Drive Element 400 Heat Dissipating Sheet 500 Heat Dissipating Member

Claims (4)

[Claims] 1. A printed circuit board on which a light emitting element is mounted on one surface side and a surface mount type driving element for driving the light emitting element on the other surface side, respectively, and a heat dissipation property to be adhered to the other surface side of the printed circuit board. A light-emitting display device comprising a sheet and a heat-dissipating member in close contact with the heat-dissipating sheet, wherein the lead wire of the light-emitting element is arranged avoiding a driving element. 2. The heat dissipating member has a frame portion for accommodating a printed circuit board and a heat dissipating sheet, and a fin portion projecting from a rear surface side of the frame portion. Emissive display device. 3. The light emitting display device according to claim 1, wherein two or three types of light emitting elements that emit different colors are used as the light emitting element. 4. The light emitting display apparatus according to claim 1, wherein the light emitting elements are arranged in a matrix.