JP2002062527A - Backlight structure of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a liquid crystal display device whose assembling stage is simplified, concerning a backlight structure of the liquid crystal display device. SOLUTION: The backlight structure of the liquid crystal display device, illuminating a liquid crystal display panel from the back surface of the liquid crystal display panel, is provided with a diffusion plate 23 which has a size corresponding to the size of the display panel 20 and one side of which is formed in a waveform, an LED 24 disposed opposite to a recessed part of the waveform of the diffusion plate 23 and a diffusion sheet 21 disposed between the display panel 20 and the diffusion plate 23. Then the diffusion plate 23 and the diffusion sheet 21 are adhered and fixed to each other by using a double coated adhesive tape 22 for shielding light, covering the near part of the waveform of the diffusion plate 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight structure for a liquid crystal display. More specifically, the present invention relates to a backlight structure of a liquid crystal display device used for displaying information of an electronic device used for a vehicle or the like.

[0002]

2. Description of the Related Art One example of a conventional backlight structure of a liquid crystal display device is shown in FIGS. FIG. 3 is an exploded perspective view, FIG.
Is an assembly sectional view. In FIG. 3, reference numeral 1 denotes a liquid crystal display panel, 2 denotes a double-sided adhesive tape, 3 denotes a diffusion sheet, 4 denotes a light shielding tape, 5 denotes a diffusion plate, 6 denotes an LED, and 7 denotes a printed circuit board.

The liquid crystal display panel 1 has a rectangular shape, and a plurality of electrodes 8 are provided on one side thereof. The double-sided adhesive tape 2 is a narrow tape and has a frame shape surrounding the periphery of the liquid crystal display panel 1 so that the diffusion sheet 3 can be adhered to the liquid crystal display panel 1. The light-shielding tape 4 is formed by applying an adhesive to one side of a narrow black tape or the like. The diffusion plate 5 is made of resin, has a size corresponding to the liquid crystal display panel 1, and has one long side formed in a wavy shape, and two short sides provided with mounting feet for mounting on a printed circuit board. 9 are provided.

Each of the above members is assembled as shown in FIG. That is, the light-shielding tape 4 is attached to the diffusion plate 5 along the side where the corrugated portion is formed, and the light-shielding tape 4 is attached to the printed circuit board 7 by the attachment feet 9. Printed circuit board 7
A plurality of LEDs 6 are respectively arranged corresponding to the concave portions of the corrugated portion of the diffusion plate 5, and the electrodes 10 are inserted into through holes formed in advance on the printed circuit board 7 and soldered.

The liquid crystal display panel 1 has a back surface to which a diffusion sheet 3 is adhered by a double-sided adhesive tape 2.
The electrode 8 is inserted into a through hole 11 formed in advance on the printed circuit board 7 and soldered.

[0006] The liquid crystal display device thus configured is an LED.
The light 7 is diffused by the diffusion plate 6, and the liquid crystal display panel 1 can be illuminated from the back by the light diffused above. At this time, the light shielding tape 4 attached to the diffusion plate 5 can prevent the strong light of the LED 6 from being seen through the liquid crystal display panel 1 from the vicinity of the waveform portion.

[0007]

In the above-mentioned conventional liquid crystal display device, a step of bonding a diffusion sheet 3 to a liquid crystal display panel 1 using a double-sided adhesive tape 2 and a step of shielding light along a corrugated portion of the diffusion plate 5 are performed. 4 is required, and there is a problem that assembling is complicated and the number of assembling steps is increased.

The present invention has been made in consideration of the above-described conventional problems, and has as its object to realize a backlight structure of a liquid crystal display device in which an assembling process is simplified.

[0009]

The backlight structure of the liquid crystal display device according to the first aspect of the present invention is a backlight structure of the liquid crystal display device illuminated from the back of the liquid crystal display panel, and corresponds to the liquid crystal display panel 20. A diffusion plate 23 having a size that is one side of which is formed in a wavy shape, an LED 24 disposed to face the wavy concave portion of the diffusion plate 23, and a gap between the liquid crystal display panel 20 and the diffusion plate 23. And a diffusion sheet 21 arranged on the diffusion plate 23, and the diffusion plate 23 and the diffusion sheet 21 are bonded and fixed by a light-shielding double-sided adhesive tape 22 that covers the vicinity of a corrugated portion of the diffusion plate 23.

A second aspect of the present invention is characterized in that the diffusion plate 23 has a rectangular or prism-shaped cross section.
A third aspect of the present invention is characterized in that a reflection film is attached to a lower surface of the diffusion plate 23.

By employing this configuration, the number of steps of bonding the diffusion sheet and the light shielding sheet becomes one, and a backlight structure of the liquid crystal display device in which the assembly step is simplified as compared with the related art can be obtained.

[0012]

1 and 2 show an embodiment of a backlight structure of a liquid crystal display device according to the present invention.
Is an exploded perspective view, and FIG. 2 is an assembled sectional view. In FIG. 1, reference numeral 20 denotes a liquid crystal display panel, 21 denotes a diffusion sheet, 22 denotes a light-shielding double-sided adhesive tape, 23 denotes a diffusion plate, 24 denotes an LED,
25 is a printed circuit board.

The liquid crystal display panel 20 has a rectangular shape.
A large number of electrodes 26 are provided on one side thereof. Also,
The diffusion sheet 21 is formed in a size corresponding to the liquid crystal display panel 1. The light-shielding double-sided adhesive tape 22 is formed by applying an adhesive to both sides of a narrow tape (about 3 mm) such as black. The diffusion plate 23 is made of resin, has a size corresponding to the liquid crystal display panel 20, has one long side formed in a wave shape, and has two short sides provided with mounting feet for mounting on a printed circuit board. 27 are provided. The cross section has a prism shape.

The above members are assembled as shown in FIG. That is, the light-shielding double-sided adhesive tape 22 is stuck to the diffusion plate 23 along the side where the corrugated portion is formed, and the diffusion sheet 21 is stuck on the light-shielding double-sided adhesive tape 22. Then, it is attached to the printed board 25 by the attachment feet 27. The printed circuit board 25 has a plurality of LEs.
D <b> 24 is arranged corresponding to each of the concave portions of the corrugated portion of the diffusion plate 23, and the electrodes 28 are inserted into through holes formed in the printed circuit board 25 in advance and soldered. In addition, the liquid crystal display panel 20 uses the electrode 26 as the printed circuit board 2.
5 is inserted into a through hole 29 formed in advance and soldered.

In the backlight structure of the liquid crystal display device according to the present embodiment, the light of the LED 24 is diffused by the diffusion plate 23 and the liquid crystal display panel 22 is illuminated from above by the light diffused above. can do.
At this time, since the light-blocking double-sided adhesive tape 22 can cut the strong light of the LED 24 that is visible from near the corrugated portion of the diffusion plate 23, it is possible to prevent uneven illumination of the liquid crystal display panel 20. In the description of the embodiment, the diffusion plate 23 has a prism-shaped cross section, but may have a rectangular shape. Alternatively, a reflection film such as an aluminum foil may be attached to the lower surface of the diffusion plate 23. good.

[0016]

According to the backlight structure of the liquid crystal display device of the present invention, the bonding process at the time of assembling is only the bonding of the diffusion sheet using the light-shielding double-sided adhesive tape. The assembly process is simplified, which can contribute to cost reduction.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a backlight structure of a liquid crystal display device of the present invention.

FIG. 2 is an assembly sectional view showing an embodiment of a backlight structure of the liquid crystal display device of the present invention.

FIG. 3 is an exploded perspective view showing an example of a conventional liquid crystal display device.

FIG. 4 is an assembled sectional view showing an example of a conventional liquid crystal display device.

[Explanation of symbols]

 Reference Signs List 20 liquid crystal display panel 21 diffusion sheet 22 light-shielding double-sided adhesive tape 23 diffusion plate 24 LED 25 printed circuit board 26, 28 electrode 27 mounting foot 29 through hole

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 33/00 F21Y 101: 02 // F21Y 101: 02 G02F 1/1335 530 F-term (Reference) 2H038 AA52 AA55 BA01 2H091 FA14Z FA23Z FA32Z FA41Z FA45Z FD06 FD11 LA12 LA13 5F041 DC23 DC83 EE23 EE24 FF01 5G435 AA17 BB12 BB15 EE27 EE34 EE41 FF06 FF08 GG23 GG26 KK05 LL07 LL08

Claims (3)

[Claims] 1. A backlight structure of a liquid crystal display device for illuminating from the back of a liquid crystal display panel, the diffusion plate having a size corresponding to the liquid crystal display panel (20) and having one side formed in a wave shape. ) And the diffusion plate (2
The LED (2) arranged opposite to the corrugated recess of (3)
4) The liquid crystal display panel (20) and the diffusion plate (23)
And a diffusion sheet (21) disposed between
A backlight structure for a liquid crystal display device, wherein the diffusion plate (23) and the diffusion sheet (21) are bonded and fixed with a light-shielding double-sided adhesive tape (22) covering the vicinity of a waveform portion of the diffusion plate (23). . 2. The backlight structure according to claim 1, wherein the diffusion plate has a rectangular or prismatic cross section. 3. The backlight structure of a liquid crystal display device according to claim 1, wherein a reflection film is adhered to a lower surface of said diffusion plate.