JP2009253098A - Led display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an LED display device that improves wide-viewing property of LED element lighting and reduces unnecessary electromagnetic wave leakage to the front face direction of a screen face. <P>SOLUTION: An LED display device 1 accommodates a printed circuit board 4 that implements a plurality of LED elements 2 on one side surface 4a in such a way that the one side surface 4a faces an opening owned by a metal case 5. On the one side surface 4a of the printed circuit board 4, an insulation resin layer 7 with a height covering the wires 3 is formed by filling a clearance between wires 3 of the LED element 2 with an insulation resin, and the metal case 5 and the wires 3 are electrically insulated. Further, on the surface of the insulation resin layer 7, a conductive resin layer 8 with a height covering the entire LED elements 2 is formed by filling a clearance between the LED elements 2 with a transparent conductive resin, to prevent electromagnetic waves leakage from the LED elements 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an LED display device, and more particularly to an electromagnetic wave leakage prevention structure of an LED element.

  2. Description of the Related Art There is an LED display device that performs screen display by selectively controlling lighting of a plurality of LED elements as a large display mainly installed outdoors. FIG. 6 is a front view (a) and a cross-sectional view (b) showing the configuration of the LED display device disclosed in Patent Document 1. An LED display device 90 shown in FIG. 6 is configured by mounting a plurality of LED elements 91 on a printed circuit board 92 and housing the printed circuit board 92 in a metal casing 93. By providing a light shielding plate 94 that surrounds the side surface of each LED element 91 and protrudes forward from each LED element 91, direct sunlight is not incident on the LED element 91 from an oblique direction, and the display contents are easy to see. It was. Further, the light shielding plate 94 is made of a conductive metal, thereby suppressing unnecessary electromagnetic waves leaking from the LED element 91.

JP 11-38905 A

  Since the conventional LED display device is configured as described above, the field-of-view range of the LED display device and the electromagnetic wave shielding effect are in a trade-off relationship. Although the visual field range is widened, the electromagnetic wave shielding effect is deteriorated and the leakage amount of unnecessary electromagnetic waves is increased. Therefore, when a wide visual field range is required for lighting the LED element, there is a problem that the amount of leakage of unnecessary electromagnetic waves from the LED element increases by shortening or not installing the light shielding plate.

  The present invention has been made to solve the above-described problems, and aims to improve the wide field of view of lighting of the LED element and to reduce leakage of unnecessary electromagnetic waves in the front direction of the display surface. And

  An LED display device according to the present invention includes a substrate on which a plurality of LED elements are mounted, an opening, a metal housing that houses the substrate so that the mounting surface of the LED elements faces the opening, and a metal housing An insulating resin layer that covers an electrode terminal of an LED element connected to the substrate, and an electrically conductive resin that is filled on the insulating resin layer. And a conductive resin layer covering the LED element exposed from the insulating resin layer.

  According to the present invention, a board on which a plurality of LED elements are mounted is housed in a metal housing having an opening so that the mounting surface of the LED element faces the opening, and the LED on the board housed in the metal housing The mounting surface of the element is filled with insulating resin to cover the electrode terminals of the LED elements connected to the substrate, and the insulating resin layer is filled with conductive resin to be exposed from the insulating resin layer. Since the LED element is covered, it is possible to widen the field of lighting of the LED element and to prevent leakage of electromagnetic waves.

Embodiment 1 FIG.
FIG. 1 is a front view (a) and a cross-sectional view (b) showing a configuration of an LED display device according to Embodiment 1 of the present invention. FIG.1 (b) is sectional drawing along the AA 'line of Fig.1 (a). The LED display device 1 shown in FIG. 1 includes a metal housing 5 that houses a printed board 4 on which a plurality of LED elements 2 each having two wires 3 that are electrode terminals are mounted vertically and horizontally.

The metal housing 5 has an opening, and the printed circuit board 4 is accommodated in the metal housing 5 so that the one-side surface 4a on which the LED element 2 is mounted faces the opening. The printed circuit board 4 and the LED element 2 are surrounded by the side wall of the metal housing 5. A plurality of LED elements 2 facing the opening of the metal housing 5 constitute a display screen.
On the back surface of the metal housing 5, input / output terminals 6 are provided that are electrically connected to the wiring pattern of the printed circuit board 4 on which the LED elements 2 are mounted. The LED display device 1 performs arbitrary screen display by controlling lighting of each LED element 2 in accordance with a signal input from the input / output terminal 6.

  An insulating resin layer 7 is formed on the one-side surface 4a of the printed board 4 by filling the insulating resin from the one-side surface 4a to a height that completely covers the wire 3 of the LED element 2. The insulating resin layer 7 fills the gap between the wires 3 and the gap between the metal housing 5 and the wire 3, whereby the metal housing 5 and the wire 3 are electrically insulated.

In addition, a conductive resin layer 8 is formed on the surface of the insulating resin layer 7 by filling a transparent conductive resin from the surface to a height that completely covers the LED element 2.
FIG. 2 is an explanatory diagram showing electromagnetic waves leaking from the LED elements. In FIG. 2, the same or corresponding parts as those in FIG. Electromagnetic waves are radiated in the front direction and the oblique direction of the LED element 2 shown in FIG.

Conventionally, in order to effectively reduce the electromagnetic wave leakage shown in FIG. 2, it is necessary to install a conductive light shielding plate 94 shown in FIG. 6 around the LED element. The conductive light-shielding plate 94 surrounding the side surface of the LED element can prevent electromagnetic wave leakage in the oblique direction, but cannot prevent electromagnetic wave leakage in the front direction.
On the other hand, in this embodiment, since the conductive resin layer 8 is configured to cover not only the side surface of the LED element 2 but also the top of the head, the leakage of electromagnetic waves in the front direction and the oblique direction of the LED element 2 is prevented. Can be prevented. In addition, since the conductive resin covering the LED element 2 is transparent, the lighting visual field range of the LED element 2 is not narrowed.

  Further, as shown in FIG. 1, the insulating resin layer 7 or the conductive resin layer 8 is formed so as to be in close contact with the inner wall surface of the metal casing 5, and the insulating resin layer 7 or the conductive resin layer 8 and the metal casing are formed. By filling the gap with the body 5, a waterproof effect can be obtained.

  As described above, according to the first embodiment, the printed circuit board 4 in which the plurality of LED elements 2 are mounted on the one-side surface 4 a is placed on the metal housing 5 so that the one-side surface 4 a faces the opening of the metal housing 5. In the LED display device 1 housed in the housing, an insulating resin layer 7 having a height that covers the wires 3 by filling the gaps of the wires 3 of the LED elements 2 with an insulating resin on the one-side surface 4a of the printed circuit board 4. Then, on the surface of the insulating resin layer 7, the gap between the LED elements 2 was filled with a transparent conductive resin to form a conductive resin layer 8 having a height that covers the entire LED element 2. Therefore, it is possible to widen the field of lighting of the LED element and to prevent leakage of electromagnetic waves.

Embodiment 2. FIG.
FIG. 3: is the front view (a) and sectional drawing (b) which show the structure of the LED display apparatus which concerns on Embodiment 2 of this invention. FIG. 3B is a cross-sectional view taken along line BB ′ of FIG. The LED display device 20 shown in FIG. 3 is conductive from the surface of the insulating resin layer 7 to a height that covers the side surface of the LED element 2 instead of the conductive resin layer 8 of the LED display device 1 of the first embodiment. A conductive resin layer 21 filled with resin is formed. For the conductive resin layer 21, a conductive resin colored opaque or black is used. In FIG. 3, the same or equivalent parts as in FIG.

  On the surface of the insulating resin layer 7, as shown in FIG. 3A, the top of the LED element 2 is left and the opaque or black conductive resin is high enough to prevent the LED element 2 from being completely hidden. By forming the layer 21, the lighting of the LED element 2 and the color of the conductive resin layer 21 are contrasted, and the contrast of the display image can be improved. Moreover, when the conductive resin layer 2 covers the side surface of the LED element 2, leakage of electromagnetic waves can be reduced.

  As described above, according to the second embodiment, the conductive resin layer 21 has a height that covers the side surface of the LED element 2 from the surface of the insulating resin layer 7 using the conductive resin colored opaque or black. Formed. Therefore, it is possible to improve the contrast of the display image.

Embodiment 3 FIG.
FIG. 4 is a front view (a) and a cross-sectional view (b) showing the configuration of the LED display device according to Embodiment 3 of the present invention. FIG. 4B is a cross-sectional view taken along the line CC ′ of FIG. The LED display device 30 shown in FIG. 4 has a configuration in which the metal conductor 31 that connects the ground layer (not shown) of the printed circuit board 4 and the insulating resin layer 8 is provided in the LED display device 1 of the first embodiment. is there. The conductive resin layer 8 is electrically connected to the ground layer of the printed circuit board 4 by the metal conductor 31. Further, the ground layer of the printed circuit board 4 is connected to the ground of the input / output terminal 6. In FIG. 4, the same or equivalent parts as in FIG.

  As described above, according to the third embodiment, the metal conductor 31 that electrically connects the ground layer of the printed circuit board 4 and the conductive resin layer 8 is provided. Therefore, ground reinforcement of the conductive resin can be realized, and the ability to prevent electromagnetic wave leakage can be improved.

  In the above description, the case where the second embodiment or the third embodiment is applied to the configuration shown in the first embodiment has been described. However, the present invention is not limited to this. Further, the configuration of the third embodiment may be appropriately combined.

Further, in Embodiment 1-3 above, the insulating resin layer or the conductive resin layer is configured to be in close contact with the inner wall surface of the metal housing in order to obtain a waterproof effect. The structure which uses a waterproof member between an LED element mounting surface and an insulating resin layer may be sufficient.
FIG. 5 is a cross-sectional view showing a configuration in which a waterproof packing is provided in the LED display device according to Embodiment 1 of the present invention. In FIG. 5, the same or corresponding parts as in FIG. The LED display device 10 shown in FIG. 5 has a configuration in which a waterproof packing 9 is provided between one surface of the printed circuit board 4 on which the LED element 2 is mounted and the insulating resin layer 7. Similarly, the LED display devices of Embodiments 2 and 3 may be configured to be provided with waterproof packing. This provides a waterproof effect.

It is the front view and sectional drawing which show the structure of the LED display apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing which shows the electromagnetic waves which leak from a LED element. It is the front view and sectional drawing which show the structure of the LED display apparatus which concerns on Embodiment 2 of this invention. It is the front view and sectional drawing which show the structure of the LED display apparatus which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the structure which provided the waterproof packing in the LED display apparatus which concerns on Embodiment 1 of this invention. It is the front view and sectional drawing which show the structure of the conventional LED display apparatus.

Explanation of symbols

  1, 10, 20, 30 LED display device, 2 LED element, 3 wire, 4 printed circuit board, 4a one side surface, 5 metal housing, 6 input / output terminal, 7 insulating resin layer, 8, 21 conductive resin layer, 9 waterproof packing, 31 metal conductor, 90 conventional LED display device, 91 LED element, 92 printed circuit board, 93 metal housing, 94 light shielding plate.

Claims (6)

A substrate on which a plurality of LED elements are mounted;
A metal housing that has an opening and accommodates the substrate so that the mounting surface of the LED element faces the opening;
An insulating resin layer made of an insulating resin filled on the mounting surface of the LED element of the substrate housed in the metal casing, and covering the electrode terminal of the LED element connected to the substrate;
An LED display device comprising: a conductive resin filled on the insulating resin layer, and a conductive resin layer covering the LED element exposed from the insulating resin layer.   The LED display device according to claim 1, wherein the conductive resin layer is made of a transparent conductive resin and covers the entire LED element exposed from the insulating resin layer.   The LED display device according to claim 1, wherein the conductive resin layer is made of an opaque conductive resin, and covers the side of the LED element exposed from the insulating resin layer.   The LED display device according to claim 3, wherein the conductive resin layer is a resin colored in black.   5. The LED display device according to claim 1, further comprising a metal conductor that electrically connects a ground layer and a conductive resin layer provided on the substrate.   6. The LED display device according to claim 1, wherein a waterproof member is provided between the mounting surface of the LED element of the substrate and the insulating resin layer.

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