Back light assembly for flat panel display

• US 6,130,658 A
• Filed: 09/30/1997
• Issued: 10/10/2000
• Est. Priority Date: 09/30/1996
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yamamoto, Koichi, Yoneya, Dai, Omori, Takayoshi
• Primary Examiner(s): Nguyen, Chanh
• Application Number:
  US08/940,976
• Time in Patent Office: 1,106 Days
• Field of Search: 345/87, 345/32, 345/102, 345/215, 349/62, 349/65, 349/70, 349/58, 349/95, 362/27, 362/30, 362/31, 362/29, 361/681, 361/682
• US Class Current: 345/102
• CPC Class Codes: G02F 1/133604 with lamps
• CPC Class Codes: G02F 1/133608 including particular frames or supporting means
• CPC Class Codes: G02F 2203/68 Green display, e.g. recycling, reduction of harmful substances
• CPC Class Codes: G09F 13/04 Signs, boards or panels, illuminated from behind the insignia

Abstract

Disclosed is a flat display allowed to facilitate a maintenance work for a back light unit contained in the flat display. The flat display includes a frame, display unit, back light unit, and chassis. The frame is positioned on the front side and has a window portion. The display unit, which is of a transmission type and is formed in a flat shape, is assembled from the rear side to the frame in such a manner as to be matched with the window portion to form an image screen. The chassis is positioned on the rear side and is engaged with the frame while putting the display unit therebetween to form a flat containing space on the back surface side of the display unit. The back light unit 3 is a surface light source which is pre-assembled using a flat case, and is removably insertable in the containing space. The back light unit functions to illuminate the transmission type display unit from the back surface side.

Claims

1. A flat display, comprising:

a frame positioned on a front side of said flat display and formed with a window portion;

a display unit having a transmission type flat panel, said display unit being assembled from a rear side to said frame in such a manner as to be matched with said window portion to form a display screen;

a chassis positioned on the rear side of said flat display, said chassis being engaged with said frame with said display unit between said chassis and said frame to form a flat containing space on a back surface side of said display unit; and

a back light unit as a surface light source for illuminating said display unit from the back surface side, said back light unit being pre-assembled using a flat case and removably insertable in said containing space.

2. A flat display according to claim 1, wherein said display unit includes:

optical parts, formed in flat shapes, for diffusing and/or collecting illuminating light coming from said back light unit; and

a liquid crystal panel for modulating the illumination light in accordance with an image signal and creating an image on the display screen;

wherein said optical parts are separated from said back light unit and are joined to a back surface of said liquid crystal panel.

3. A flat display according to claim 2, wherein said optical parts include:

a light diffusion plate for diffusing illumination light in both vertical and horizontal directions of the display screen; and

a prism sheet for collecting the illumination light, which has been once diffused, at least in the vertical direction.

4. A flat display according to claim 2, wherein said liquid crystal panel includes:

scanning lines composed of discharge channels extending in a horizontal direction and arranged with a specific pitch in a vertical direction;

signal lines composed of signal electrodes extending in the vertical direction and arranged with a specific pitch in the horizontal direction; and

pixels composed of liquid crystal, interposed at crossing points between said scanning lines and said signal lines.

5. A flat display according to claim 1, wherein said back light unit has a light diffusion plate having a relatively high light-transmittance and mounted on a front side of said back light unit.

6. A flat display according to claim 5, wherein said display unit has a light diffusion plate having a relatively low light-transmittance and mounted on a rear surface of said display unit.

7. A flat display according to claim 2, wherein said display unit has a structure in which a space formed between said liquid crystal panel and said optical parts are enclosed from an exterior.

8. A flat display as claimed in claim 1, wherein said back light unit includes a plurality of elongated lamps arranged parallel to one another and position at said back surface side of said display unit.