IP Library Granted Patent US 8,164,712
Granted Patent B2
US 8,164,712 · App. 12/192,181 · Granted Apr 24, 2012

Liquid crystal display device

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Quick Facts
Patent No.
US 8,164,712
App. No.
12/192,181
Granted
Apr 24, 2012
Kind
B2
Abstract

A liquid crystal display device includes a backlight device, a liquid crystal panel and a light source unit. The light source unit includes a case having an opening surface, a fluorescent tube, an electric holder, and a cover member. The cover member includes a shield plate, a fixed groove and an overhanging portion, wherein the overhanging portion is provided at an edge of the fixed groove and on a side of the liquid crystal panel with respect to the fluorescent tube which includes a portion which extends through the fixed groove. A portion of the cover member includes a protrusion which is a separate member from the overhanging portion and which extends more toward the liquid crystal panel than a surface portion of the overhanging portion.

Claims (53)

1. A liquid crystal display device comprising:

a liquid crystal panel; and

a light source unit for illuminating the liquid crystal panel from a back side of the liquid crystal panel, wherein

the light source unit includes:

a case having an opening surface;

a fluorescent tube provided in the case and having a longitudinal axis;

an electrode holder provided in the case and holding an electrode section formed in an edge portion of the fluorescent tube; and

a cover member having a shield plate for shielding the electrode holder from a diffusion area in which light emitted by a light emitting section provided in the fluorescent tube is scattered, wherein

the cover member includes:

a fixed groove through which the fluorescent tube extends; and

an overhanging portion, which is provided at an edge of the fixed groove and on the side of the liquid crystal panel with respect to the fluorescent tube, faces the fluorescent tube, and protrudes toward the inside of the case and in the direction of the longitudinal axis of the fluorescent tube, and wherein

when a plane which includes the overhanging portion, is perpendicular to a surface of the liquid crystal panel, and is substantially parallel to the longitudinal axis of the fluorescent tube, is S 1 ; a plane which includes a portion of the shield plate and is perpendicular to the surface of the liquid crystal panel is S 2 , the portion of the shield plate not including the overhanging portion; and a plane which includes the overhanging portion and is parallel to the surface of the liquid crystal panel is S 3 , a cross sectional shape of a portion of the cover member, which is taken along the plane S 1 and located on the side of the liquid crystal panel with respect to the plane S 3 , is different from a cross sectional shape of a portion of the cover member, which is taken along the plane S 2 and located on the side of the liquid crystal panel with respect to the plane S 3 , and the portion of the cover member, which has the cross sectional shape taken along the plane S 1 and located on a front side of the plane S 3 in a direction toward the liquid crystal panel, includes a protrusion which faces the liquid crystal panel and which extends closer to the liquid crystal panel than a surface portion of the overhanging portion which lies in the plane S 3 .

2. The liquid crystal display device according to claim 1 , wherein

the protrusion includes a reflector having at least two reflective surfaces is provided for the fixed groove and located on a surface of the cover member and on the side of the liquid crystal panel with respect to the overhanging portion, and one of planes, each of which includes a boundary between the reflective surfaces and is perpendicular to the surface of the liquid crystal panel, includes an area present around the center of the fluorescent tube, the center of the fluorescent tube being determined in a cross section of the fluorescent tube taken along a plane perpendicular to the planes S 1 and S 3 .

3. The liquid crystal display device according to claim 2 , wherein

the reflective surfaces of the reflector are substantially symmetrical to the plane S 1 including an area present around the center of the fluorescent tube, the center of the fluorescent tube being determined in a cross section of the fluorescent tube taken along a plane perpendicular to the planes S 1 and S 3 , and wherein

the reflector is located on the surface of the cover member and on the side of the liquid crystal panel with respect to the overhanging portion.

4. The liquid crystal display device according to claim 1 , wherein

the overhanging portion has a surface substantially parallel to the surface of the liquid crystal panel and a surface substantially perpendicular to the surface of the liquid crystal panel.

5. The liquid crystal display device according to claim 2 , wherein

the portion of the cover member, which has the cross sectional shape taken along the plane S 2 , is bent toward the opposite side to the liquid crystal panel between the fluorescent tubes adjacent to each other.

6. The liquid crystal display device according to claim 1 , wherein the fluorescent tube is an external electrode fluorescent lamp.

7. A liquid crystal display device comprising:

a liquid crystal panel; and

a light source unit for illuminating the liquid crystal panel from a back side of the liquid crystal panel, wherein

the light source unit includes:

a case having an opening surface;

a fluorescent tube provided in the case and having a longitudinal axis;

an electrode holder provided in the case and holding an electrode section formed in an edge portion of the fluorescent tube; and

a cover member having a shield plate for shielding the electrode holder from a diffusion area in which light emitted by a light emitting section provided in the fluorescent tube is scattered, wherein

the cover member includes:

a fixed groove through which the fluorescent tube extends; and

an overhanging portion, which is provided at an edge of the fixed groove and on the side of the liquid crystal panel with respect to the fluorescent tube, faces the fluorescent tube, and protrudes toward the inside of the case and in the direction of the longitudinal axis of the fluorescent tube, wherein

the overhanging portion has a surface substantially parallel to a surface of the liquid crystal panel and a surface substantially transverse to the surface of the liquid crystal panel, and wherein

the surface of the overhanging portion, which is substantially parallel to the surface of the liquid crystal panel, extends more toward the inside of the case and in the direction of the longitudinal axis of the fluorescent tube than the surface of the overhanging portion, which is substantially perpendicular to the surface of the liquid crystal panel.

8. The liquid crystal display device according to claim 1 , wherein the protrusion includes a reflector provided on the side of the liquid crystal panel with respect to the overhanging portion and protrudes toward the liquid crystal panel.

9. A liquid crystal display device comprising:

a liquid crystal panel; and

a light source unit for illuminating the liquid crystal panel from a back side of the liquid crystal panel, wherein

the light source unit includes:

a case having an opening surface;

a fluorescent tube provided in the case and having a longitudinal axis;

an electrode holder provided in the case and holding an electrode section formed in an edge portion of the fluorescent tube; and

a cover member having a shield plate for shielding the electrode holder from a diffusion area in which light emitted by a light emitting section provided in the fluorescent tube is scattered, wherein

the cover member includes a fixed groove through which the fluorescent tube extends, wherein

the cover member has an upper surface substantially parallel to the surface of the liquid crystal panel and is present at locations around left and right edge portions of the liquid crystal panel, wherein

when sections present on the boundary between the upper surface and the shield plate of the cover member are defined as diffusion area start sections, at least one of the diffusion area start sections, which is present at top and bottom edge portions of the cover member, is located on the outer side of the case with respect to the other diffusion area start section present around the center of the boundary between the upper surface and the shield plate of the cover member.

10. The liquid crystal display device according to claim 1 , wherein a white elastic body is provided between the overhanging portion and the fluorescent tube.

11. The liquid crystal display device according to claim 4 , wherein the surface of the overhanging portion, which is substantially parallel to the surface of the liquid crystal panel, extends more toward the inside of the case and in the direction of the longitudinal axis of the fluorescent tube than the surface of the overhanging portion, which is substantially perpendicular to the surface of the liquid crystal panel.

12. The liquid crystal display device according to claim 1 , wherein the protrusion extends closer to the liquid crystal panel than the portion of the cover member having the cross sectional shape taken along the plane S 2 and located on the front side of the plane S 3 .

13. The liquid crystal display device according to claim 7 , wherein the surface of the overhanging portion which is substantially transverse to the surface of the liquid crystal panel is substantially perpendicular to the liquid crystal panel.

14. The liquid crystal display device according to claim 1 ,

wherein when sections present on a boundary between an upper surface of the cover member and the shield plate of the cover member are defined as diffusion area start sections, at least one of the diffusion area start sections, which is present at top and bottom edge portions of the cover member, is located on the outer side of the case with respect to the other diffusion area start section present around the center of the boundary between the upper surface and the shield plate of the cover member.

Assignments (3)
CHANGE OF NAME Recorded May 10, 2011
From: IPS ALPHA TECHNOLOGY, LTD.
To: PANASONIC LIQUID CRYSTAL DISPLAY CO., LTD.
Reel/Frame 026257/0377 →
CORRECTIVE ASSIGNMENT TO CORRECT THE ORIGINAL ELECTRONIC COVER SHEET, THE 3RD INVENTOR'S EXECUTION DATE IS INCORRECT AND THE 2ND ASSIGNEE IS MISSING, PREVIOUSLY RECORDED ON REEL 021393 FRAME 0980. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Nov 17, 2010
From: SEKIGUCHI, YOSHIFUMI; AONO, YOSHINORI; TSUBOKURA, MASAKI
To: HITACHI DISPLAYS, LTD.; IPS ALPHA TECHNOLOGY, LTD.
Reel/Frame 025384/0073 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 15, 2008
From: SEKIGUCHI, YOSHIFUMI; AONO, YOSHINORI; TSUBOKURA, MASAKI
To: HITACHI DISPLAYS, LTD.
Reel/Frame 021393/0980 →