JP2001177154A - Led display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED display device causing no trouble to peripheral equipment by eliminating a switching noise to the outside from a display unit when an LED is turned ON, OFF. SOLUTION: A shield material 5 conductively connected to the ground line is provided between a display unit board 2 having many LEDs 2a of pixel units and disposed in a frame 4 arranged on a light emitting display surface on the front surface and a circuit board 3 having a circuit conducted to the LEDs 2a disposed at an interval on the rear surface of the board 2. Thus, when the LEDs 2a are turned ON, OFF, an electromagnetic noise generated at the board 3 is shielded by the material 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LED display device equipped with a light-emitting diode used for a large-screen light-emitting display or the like, and more particularly, to a radio wave caused by noise emitted from a circuit section when the LED is turned on and off. The present invention relates to an LED display device capable of preventing occurrence of a failure.

[0002]

2. Description of the Related Art For example, a large-screen full-color light-emitting display device uses a combination of red (R), green (G), and blue (B) light-emitting diodes (hereinafter, referred to as "LED") as one dot. In general, the LED display provided is arranged on the entire screen. LED display,
FIG. 2 is a schematic side view of a combination of an LED display unit and a circuit unit for controlling lighting of each LED.

As shown in the figure, an LED display 1 has a display unit substrate 2, a circuit unit substrate 3 disposed on the back surface thereof, and a frame 4 for inserting and supporting the display unit substrate 2 from the back surface side.
Is a combination of The display substrate 2 is composed of R, G,
The dots of the combination of the LEDs 2a of B are arranged in a matrix, and the leads (not shown) of the LEDs 2a are held in a state of protruding to the rear side.
In addition, a boss (not shown) for attaching to the housing of the light emitting display is provided on the back surface of the display unit substrate 2, and a pin header 2 b for conducting connection with the wiring pattern of the circuit unit substrate 3 is provided. . Circuit board 3 is L
A circuit component 3a such as an IC, a transistor and a power supply connector for driving and lighting control of the ED 2a is mounted. Then, a wiring pattern connected to the power connector is formed on the back surface, and the pin header 2b of the display unit substrate 2 is conducted to the wiring pattern to integrate the display unit substrate 2 and the circuit unit substrate 3. In addition, the frame 4 is provided with a mounting hole for inserting the LEDs 2a arranged on the display unit substrate 2 and facing the front according to the arrangement pattern of the dots.
On the front surface side, a hood 4a for suppressing interference due to insertion of sunlight or the like is formed for each row of dots.

[0004] The display of images and characters by the LED display 1 is performed by the LED of each dot arranged on the display section substrate 2.
By controlling the lighting of 2a, full-color light emission display is possible.

[0005]

When on / off control of the LED 2a is performed, switching noise is generated from the entire circuit part including the circuit parts 3a and the wiring pattern from the power connector. This noise also has a subtle effect on the control of energization of the LED 2a, making the blinking control unstable and deteriorating the displayed image. In order to prevent such an influence on the power supply control to the LED 2a, the circuit board 3
The improvement can be achieved by incorporating an appropriate protection circuit before D2a.

However, the generation of switching noise itself cannot be suppressed, and this noise passes through the display substrate 2 as electromagnetic waves and is emitted to the outside. When the electromagnetic waves are emitted in this way, electric and electronic devices around the light emitting display are hampered by radio waves. Therefore, troubles of devices around the light emitting display are caused, and the light emitting display itself cannot be installed in a place where many devices are arranged.

The present invention provides an LED display that does not cause trouble in peripheral devices by preventing switching noise generated when the LED is turned on and off from passing through the display unit and being emitted to the outside. The purpose is to:

[0008]

According to the present invention, there is provided a frame arranged on a light emitting display surface, a display unit substrate arranged in the frame, and a large number of LEDs arranged in units of pixels facing the front surface thereof, A circuit board provided with a circuit section that is arranged at an interval on the back side of the display section board and is electrically connected to the LED; and at least one of the display section board and the circuit section board. To
Or between these display board and circuit board,
It is characterized by having a shield structure for blocking electromagnetic noise from the circuit part substrate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 comprises a frame arranged on a light emitting display surface, and a display board having a large number of LEDs arranged in the frame and arranged in a pixel unit facing the front surface. A circuit portion substrate provided with a circuit portion that is arranged on the rear surface side of the display portion substrate at an interval and that is electrically connected to the LED, wherein at least one of the display portion substrate and the circuit portion substrate is provided. An LED display device comprising a shield structure for blocking electromagnetic wave noise from the circuit portion substrate on one side or between the display portion substrate and the circuit portion substrate. Since the electromagnetic wave noise generated from the circuit board during the off-operation is cut off by the shield structure, the electromagnetic wave is prevented from being emitted to the outside from the display board. It is having an effect.

The invention according to claim 2 is characterized in that the shield structure is a shield material that is conductively connected to a ground line and blocks the passage of electromagnetic noise from the circuit board to the display board. The LED according to claim 1.
A display device, which has an effect of preventing electromagnetic waves generated from a circuit board when an LED is turned on and off by a shield material, thereby preventing electromagnetic waves from being emitted from the display board to the outside. .

According to a third aspect of the present invention, the shield material is fixed by being fitted in an insulated state with a pin header protruding from a back surface of the display portion substrate and conducting to a circuit of the circuit portion substrate. 3. The LED display device according to claim 2, wherein the pin header can be used for both conduction between the circuit board and the LED side and for fixing the shielding material.

According to a fourth aspect of the present invention, in the LED display device according to the second or third aspect, the shield material is made of a conductive material such as copper, aluminum, or carbon. The shield material has an effect of preventing electromagnetic waves from being emitted from the display unit substrate to the outside.

According to a fifth aspect of the present invention, in the LED according to the first aspect, the shield structure comprises the frame and a hood formed in a lattice on the front surface of the frame made of a conductive resin. The display device has a function of being able to perform a shielding function by a frame and a hood on a front surface thereof.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an LED according to an embodiment of the present invention.
It is a schematic right side view of a display. The same components as those in the conventional example shown in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

The LED display 1 comprises a display unit substrate 2, a circuit unit substrate 3, and a frame 4 as in the conventional example.
The back of the frame 4 is fixed to the housing 10 with mounting screws passing through the housing 10 of the light emitting display. LED 2a and pin header 2 provided on display substrate 2
The components b and the circuit components 3a provided on the circuit board 3 are exactly the same as those of the conventional example shown in FIG.

A shield member 5 is provided between the frame 4 and the circuit board 3 for blocking noise emitted from the circuit of the circuit board. The shielding material 5 is formed of a material having a shielding effect of blocking passage of electromagnetic waves, such as aluminum or copper. Then, a through hole 5a through which the pin header 2b passes is formed in the shield material 5, and the pin header 2b is fitted into the through hole 5a so that the shield material 5 is electrically insulated. It is fixed between the substrate 2.

To electrically connect the shield member 5 to the ground line, a signal ground 3b is provided on the front surface of the circuit board 3 or a ground portion 10a is provided on the front surface of the housing 10.
Place. When the signal ground 3b is provided,
The shield material 5 is conducted to the signal ground 3b by the lead wire 3c in the figure. In the case where the ground portion 10a is provided in the housing 10, the shield member 5 is electrically connected to the ground portion 10a by a lead wire 10b indicated by a two-dot chain line in the drawing.

In the above configuration, the shielding member 5 electrically connected to the signal line 3b of the circuit board 3 or the ground portion 10a of the housing 10 and electrically connected to the ground line.
Are located on the front side of the circuit section substrate 3. For this reason, LE
Switching noise generated from the circuit of the circuit unit substrate 3 when the D2a turns on and off is blocked by the shield member 5. That is, by making the thickness of the shield member 5 between the circuit part substrate 3 and the display part substrate 2 appropriate, electromagnetic wave noise such as switching noise generated in the circuit part substrate 3 penetrates into the shield member 5. Sometimes attenuated. Then, the shielding member 5 is connected to the ground portion 1 of the housing 10.
Since it is conducted to 0a, the electromagnetic wave noise can escape to the housing 10 side via the shield member 5, and a large shielding effect can be obtained.

As described above, the electromagnetic wave due to the switching noise is effectively attenuated by the shield member 5,
Emission to the outside from the display unit substrate 2 is suppressed. For this reason, even in the case of a large-screen light-emitting display constructed by arranging a large number of LED displays 1, the emission of electromagnetic waves from the screen is reduced, causing radio interference and trouble in nearby electric and electronic devices. I won't let you.

In the above embodiment, the shield member 5 is disposed between the display substrate 2 and the circuit substrate 3. However, the shield material is provided on either the display substrate 2 or the circuit substrate 3. A shield structure made of a material or the like may be provided. Also, a frame 4 and a hood 4 formed in a grid on the front surface thereof.
By using a as a conductive resin, it is possible to form a shield structure by the frame 4 and the hood 4a, and in this case, emission of the electromagnetic wave from the display substrate 2 can be prevented. The hood 4a may be made of metal such as aluminum.

[0022]

According to the present invention, since a shield mechanism such as a shield material for blocking switching noise is provided between the circuit board and the display board or at one of these boards, the display board is arranged. The emission of electromagnetic waves from the screen of the LED display device thus suppressed can be suppressed, and radio interference and interference with the operation of peripheral devices can be prevented. For this reason, even if various devices are arranged around, you can set the display,
There is no restriction on the installation position, and the versatility can be improved.

In the case where the shield material is fixed by a pin header that conducts to the ground line, the pin header can be used for both conduction between the circuit board and the LED side and for fixing the shield material. Can also be used by easily changing to one with a shield material attached.

Further, the emission of electromagnetic waves from the display substrate can be prevented by using a conductive resin for the frame arranged on the light emitting display surface and the grid-shaped hood on the front surface thereof, and there is no need to separately arrange a shielding material. , The structure becomes simpler.

[Brief description of the drawings]

FIG. 1 is a right side view schematically showing an LED display device of the present invention.

FIG. 2 is a right side view schematically showing a conventional LED display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED display 2 Display part board 2a LED 2b Pin header 3 Circuit part board 3a Circuit parts 3b Signal ground 3c Lead wire 4 Frame 4a Hood 5 Shielding material 5a Through hole 10 Housing 10a Ground part 10b Lead wire

Continued on the front page (72) Inventor Tetsuya Fukudome 1-1, Komachi, Takatsuki-shi, Osaka Matsushita Electronics Co., Ltd. F-term (reference) 5C094 AA09 AA21 BA25 CA18 CA24 FB01 FB12 5F041 AA31 BB06 BB33 DC07 FF06 5G435 AA16 BB04 CC09 CC12 EE36 GG27 GG33 HH12

Claims (5)

[Claims] 1. A frame arranged on a light emitting display surface, a display unit substrate incorporated in the frame and arranged in a large number with LEDs in pixel units facing the front surface, and a space on the back surface side of the display unit substrate. And a circuit portion board provided with a circuit portion that is electrically connected to the LED, and is provided on at least one of the display portion substrate and the circuit portion substrate, or these display portion substrates. An LED display device comprising: a shield structure for intercepting electromagnetic wave noise from the circuit unit substrate between the circuit unit substrates. 2. The LED according to claim 1, wherein the shield structure is a shield material that is conductively connected to a ground line and blocks passage of electromagnetic wave noise from the circuit board to the display board. Display device. 3. The semiconductor device according to claim 2, wherein the shield material is fitted and fixed in an insulated state with a pin header protruding from a back surface of the display unit substrate and electrically connected to a ground line of the circuit unit substrate. LED display device. 4. The shielding material is made of copper, aluminum,
The LED display device according to claim 2, wherein the LED display device is a conductive material such as carbon. 5. The LED display device according to claim 1, wherein in the shield structure, the frame and a hood formed in a lattice on a front surface of the frame are made of a conductive resin.