JP2000206906A - Led display device and light diffusion sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED display device which is capable of protecting an LED display element from static electricity. SOLUTION: This LED display device has a substrate 4 arranged with the LED display element 2 and reflection frame 3 on its front surface, a light diffusion sheet 5 stuck top the reflection frame 3 and a metallic frame 6 fixed to the rear surface of the substrate 4. A light shieldable conductive layer 52 exclusive of light transparent areas 51 of LED is integrally formed on the light diffusion sheet 5 and the conductive layer 52 is connected to the metallic frame 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an LED display device and a light diffusion sheet used therein.

[0002]

2. Description of the Related Art A large dot matrix type display system such as a message board is disclosed in, for example, JP-A-8-27.
It can be assembled by combining a plurality of small dot matrix type LED display devices each having a length of several centimeters as disclosed in Japanese Patent No. 2317. When handling the display device at the time of assembly, static electricity may be applied to the display device via an assembling worker, and this static electricity may damage the LED display element. In particular, LE
D display element has high brightness (about 1 cd) blue or green LE
In the case of D, the breakdown voltage with respect to static electricity is relatively low, and it tends to be easily damaged by static electricity.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an LED display device capable of protecting an LED display element from static electricity.

[0004]

According to a first aspect of the present invention, there is provided an LED display device having a light diffusion sheet affixed to an upper surface thereof.
The light-shielding conductive layer is formed integrally except for the light transmission region of the ED display element.

According to a second aspect of the present invention, there is provided an LED display device comprising: a substrate on which an LED display element and a reflection frame are arranged on an upper surface; a light diffusion sheet attached to an upper surface of the reflection frame; A metal frame fixed to the lower surface of the light diffusion sheet, a light-blocking conductive layer is integrally formed on the light diffusion sheet except for a light transmitting region of the LED display element, and the conductive layer is formed of the metal frame. Characterized in that it is connected to

In the light diffusion sheet of the present invention, a light-shielding conductive layer is integrally formed on the light diffusion layer in a predetermined pattern, and a grounding connection piece is partially formed on the light diffusion layer. It is characterized by being provided integrally.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of the display device 1 of the present invention, FIG. 2 is a plan view of a light diffusion sheet used by being attached to the upper surface of the display device 1, and FIG. 3 is an enlarged cross-sectional view of a main part of the light diffusion sheet.

[0008] As shown in FIG.
Substrate 4 on which LED display element 2 and reflection frame 3 are arranged on the upper surface
A light diffusion sheet 5 attached to the upper surface of the reflection frame 3,
A metal frame 6 fixed to the lower surface of the substrate 4.

The LED display element 2 is a LED in a chip state.
, And one or a plurality of pixels are used to constitute one pixel unit. These pixel units are arranged in a matrix, but may be arranged corresponding to characters and numerals. The reflection frame 3 includes a frame having a reflection surface 31 inclined to surround each pixel unit.
In order to enhance light reflectivity, it is made of a white resin frame. A plurality of boss pins 32 are integrally formed on the back surface of the reflection frame 3.
And is integrally fixed to the upper surface of the. The boss pin 32 is also used for fixing the frame 6 by fusing the tip after penetrating the substrate 4 and the frame 6. The frame 6 is formed by a metal frame having a U-shaped cross section including a surface 61 located on the back side of the substrate 4 and a pair of mounting surfaces 62, 62 extending downward from both sides of the surface.

Below the board 4, a plurality of connector pins 7
A driving substrate 8 connected and fixed to the substrate 4 is arranged. On the back side of the substrate 8, a connector 9 for a cable,
9 are provided.

The light diffusion sheet 5 has a light-shielding conductive layer 52 formed on the upper surface thereof in a predetermined pattern. That is, as shown in the plan view of FIG. 2, the light diffusing sheet 5 has a portion excluding the transmission regions 51, 51 for transmitting light emitted from the LED display elements 2 arranged in a matrix (the hatching in FIG. 2). The light-shielding conductive layer 52
Are integrally formed, and a connection piece 53 for grounding is formed.
Are integrally formed. The conductive layer 52 is formed corresponding to the upper surface of the reflection frame 3. The light diffusion sheet 5 is shown in FIG.
As shown in the enlarged cross-sectional view, an optical sheet having a light diffusion layer 56 on the upper surface of the base material layer 55 and an adhesive layer 54 on the lower surface is used as a basic sheet, and the upper surface has conductivity and light shielding properties such as aluminum foil. The conductive layer 52 provided is adhered by an adhesive layer 57 to be integrated. When a material having high light reflectivity such as aluminum is used for the conductive layer 52, it is desirable to form a black light-absorbing coating 58 for preventing light reflection on the surface thereof. Also, light diffusion sheet 5
By attaching an easily peelable sheet (not shown) to the lower surface of the adhesive layer 54, the handling can be improved.

The connecting piece 53 for grounding is bent downward at the end of the reflection frame 3 as shown in FIG. 1, and an adhesive tape or the like is attached so that the conductive layer 52 keeps contact with the frame 6. It is fixed to the frame 6 by means 10.

The display device 1 configured as described above is used as a screen component of a large display device (not shown), and is arranged in a matrix along a mounting bar (not shown) for mounting the large display device. Placed and assembled by securing the frame portion to the crosspiece. In such assembling, when the assembling worker handles the display device 1, static electricity charged to the worker may be discharged to the display device 1, and the LED display element 2 is destroyed by such discharge. Was feared. However, the light diffusion sheet 5 has L
Since the light-shielding conductive layer 52 is formed integrally except for the light transmission region 51 of the ED, the conductive layer 52 functions as a discharge path for static electricity, thereby preventing the LED display element 2 from being broken by the discharge. It can be prevented beforehand.
Further, since the conductive layer 52 has a light-shielding property, unnecessary light (light leaking from an adjacent portion or the like) can be cut off as compared with the case where a light-transmitting material is used, and the outline of the pixel is made clear to make the display clear. The contrast can be increased.

Since the conductive layer 52 of the light diffusion sheet 5 is connected to the metal frame 6 fixed to the lower surface of the substrate 4, the conductive layer 52 and the frame 6 function as a discharge path for static electricity. LE by electrostatic discharge
The D display element 2 can be prevented from being destroyed. Particularly, in a structure in which the LED display element 2 is directly arranged on the substrate 4, the conductive layer 52 and the frame 6 are
Since the LED display element 2 is arranged so as to cover the upper and lower sides of the D display element 2, it is possible to more reliably prevent the LED display element 2 from being destroyed by electrostatic discharge.

[0015]

As described above, according to the present invention, it is possible to provide an LED display device which can protect the LED display element from static electricity, and has few failures and can be easily handled.

[Brief description of the drawings]

FIG. 1 is a sectional view of an LED display device according to an embodiment of the present invention.

FIG. 2 is a plan view of a light diffusion sheet according to an example of the present invention.

FIG. 3 is an enlarged sectional view of a main part of a light diffusion sheet according to an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED display device 2 LED display element 3 Reflection frame 4 Substrate 5 Light diffusion sheet 52 Conductive layer 6 Frame

Continued on the front page (72) Inventor Takashi Yamaoka 3-201 Minamiyoshikata, Tottori City, Tottori Prefecture F-term (reference) in Sanyo Electric Co., Ltd. 5C094 AA21 BA25 CA19 DA20 ED20 HA10 5G435 AA16 BB04 EE05 FF06 GG32 LL00

Claims (3)

[Claims] 1. An LED display device having a light diffusion sheet attached to an upper surface thereof, wherein a light-shielding conductive layer is integrally formed on the light diffusion sheet except for a light transmitting region of the LED display element. Display device. 2. A light-emitting device comprising: a substrate on which an LED display element and a reflection frame are arranged on an upper surface; a light diffusion sheet attached to an upper surface of the reflection frame; and a metal frame fixed to a lower surface of the substrate. An LED display device, wherein a light-shielding conductive layer is integrally formed on a diffusion sheet except for a light transmitting region of an LED display element, and the conductive layer is connected to the metal frame. 3. A light diffusion sheet, wherein a light-shielding conductive layer is integrally formed on a light diffusion layer in a predetermined pattern, and a grounding connection piece is integrally provided on a part of the light diffusion layer.