Backlight device for display system providing enhanced peripheral illumination

• US 7,591,563 B2
• Filed: 01/15/2004
• Issued: 09/22/2009
• Est. Priority Date: 01/15/2004
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Lin, Yi-Chun, Chou, Shen-Hong
• Primary Examiner(s): Lee; Jong-Suk (James)
• Assistant Examiner(s): MACCHIAROLO, LEAH SIMONE
• Application Number:
  US10/758,364
• Publication Number:
  US 20050174318A1
• Time in Patent Office: 2,077 Days
• Field of Search: 362/613, 362/608, 362/621, 362632-634, 362/800, 362/217, 362/222, 362/223, 362/235, 362/236, 362/240, 362/246, 362/248, 362/631, 362/217.1, 362/217.11, 362/362, 362/29, 362/30, 362 971- 973, 349/66
• US Class Current: 362/97.3
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

The present application describes a backlight device for providing enhanced peripheral illumination of light modulators in display systems. In one embodiment, a display system includes a light modulator, a light diffusing plate, and a backlight device. The backlight device includes light sources that are distributed over an area that is at least equal to or greater than an image display area of the light modulator. In another embodiment, an edge-lit type backlight device is described. The edge-lit type backlight device includes a light guide plate for directing light towards the light modulator. The edge-lit type backlight device further includes light sources that are distributed along a side edge of the light guide plate. The light sources are distributed along a length that is at least equal to or greater than a corresponding length of an image display area of the light modulator.

Claims

1. A display device comprising:

a display panel having a display area for displaying images;

a backlight device coupled to the display panel, including;

a circuit board;

a plurality of light sources distributed on the circuit board with a light distribution surface area; and

a device case enclosing the plurality of light sources, wherein the device case comprises a plurality of sidewalls having an inner surface configured to reflect light from the plurality of light sources, wherein each sidewall of the device case and the circuit board form an angle in the range of about 60 degrees to less than 90 degrees; and

at least one light-diffusing plate optically coupled between the plurality of light sources and the display panel, the at least one light-diffusing plate having a light incidence area for receiving light from the plurality of light sources, wherein the light incidence area of the at least one light-diffusing plate is substantially equal to the display area, and the light distribution surface area is greater than the light incidence area.

2. The display device according to claim 1, wherein the display area has a width ‘

A ’ and

a length ‘

B’

;

each one of the plurality of light sources is separated from adjacent light sources by a pitch ‘

G’

; and

the light distribution surface area ‘

S’

is confined to the range defined by (A+G)×

(B+G)≦

S≦

(A+3G)×

(B+3G).

3. The display device according to claim 1, wherein the display panel is a liquid crystal display panel.

4. The display device according to claim 1, wherein the plurality of light sources are light-emitting diodes.

5. The display device according to claim 1, wherein the plurality of light sources are distributed in an array.

6. The display device according to claim 1, wherein a portion of at least one of the plurality of sidewalls of the device case is curved.

7. The display device according to claim 1, wherein the inner surface of at least one of the plurality of sidewalls of the device case is configured to scatter light within the device case.

8. A display device comprising:

a display panel having a display area for displaying images;

a backlight device coupled to the display panel, including;

a circuit board;

a plurality of light sources distributed on the circuit board with a light distribution surface area; and

a device case enclosing the plurality of light sources, wherein the device case comprises a plurality of sidewalls having an inner surface configured to reflect light from the plurality of light sources, wherein each sidewall of the device case and the circuit board form an angle in the range of about 60 degrees to less than 90 degrees; and

wherein the light distribution surface area is greater than the display area.