IP Library Granted Patent US 6,955,460
Granted Patent B2
US 6,955,460 · App. 10/320,413 · Granted Oct 18, 2005

LCD backlight unit having 40° half power angle without a polarizing sheet

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Quick Facts
Patent No.
US 6,955,460
App. No.
10/320,413
Granted
Oct 18, 2005
Kind
B2
Abstract

A backlight unit includes a light emission part having a lamp for emitting light beams and a lamp housing for mounting the lamp therein and for reflecting the light beams from the lamp; a light guide panel for guiding the light beams from the light emission part; a reflecting plate under the light guide panel for reflecting the light beams that progress to a lower surface and a side surface of the light guide panel; a diffusion sheet having a thickness of about 113 μm for diffusing the light beams that have passed through the light guide panel; and a prism sheet having a thickness of about 165 μm and having a half-power angle of at least about 40° for controlling progress directions of the light beams that have passed through the diffusion sheet.

Claims (25)

1. A backlight optical device having a 40° half-power angle without a polarizing sheet and to be coupled with a light emission part that emit light beams, the device comprising:

a light guide panel configured to guide the light beams from the light emission part;

a reflecting plate under the light guide panel for reflecting the light beams that progress to a lower surface and a side surface of the light guide panel;

a diffusion sheet for diffusing the light beams that have passed through the light guide panel; and

a prism sheet having a thickness of about 165 μm and having a matte texture layer uniformly disposed on a bottom surface of the prism sheet for controlling progress directions of the light beams that have passed through the diffusion sheet.

2. The device according to claim 1 , wherein the diffusion sheet is a polyester film having a haze of about 81.4%, a spectral transmittance of about 64.5%, and a total ray transmittance of about 77.6%.

3. The backlight unit according to claim 1 , wherein the prism sheet includes:

a condensing film for condensing light beams; and

a lenticular layer extending in a specific direction on an upper surface of the condensing film,

wherein the matte texture layer uniformly disposed on a lower surface of the condensing film for dispersing light beams.

4. The backlight unit according to claim 3 , wherein the lenticular layer includes a plurality of dome-shape prisms arranged along a direction.

5. The backlight unit according to claim 4 , wherein an apex angle of each prism is about 90° and a pitch of the prisms is about 50 μm.

6. A backlight unit having a 40° half-power angle without a polarizing sheet, comprising:

a light emission part having a lamp for emitting light beams and a lamp housing for mounting the lamp therein and for reflecting the light beams from the lamp;

a light guide panel for guiding the light beams from the light emission part;

a reflecting plate under the light guide panel for reflecting the light beams that progress to a lower surface and a side surface of the light guide panel;

a diffusion sheet for diffusing the light beams that have passed through the light guide panel; and

a prism sheet having a matte texture layer uniformly disposed on a bottom surface of the prism sheet for controlling progress directions of the light beams that have passed through the diffusion sheet.

7. The backlight unit according to claim 6 , wherein the diffusion sheet is a polyester film having a haze of about 81.4%, a spectral transmittance of about 64.5%, and a total ray transmittance of about 77.6%.

8. The backlight unit according to claim 6 , wherein the prism sheet includes:

a condensing film for condensing light beams and;

a lenticular layer extending in a specific direction on an upper surface of the condensing film,

wherein the matte texture layer is uniformly disposed on a lower surface of the condensing film for dispersing light beams.

9. The backlight unit according to claim 8 , wherein the lenticular layer includes a plurality of dome-shape prisms arranged along a direction.

10. The backlight unit according to claim 9 , wherein an apex angle of each prism is about 90° and a pitch of the prisms is about 50 μm.

Assignments (2)
CHANGE OF NAME Recorded Oct 17, 2008
From: LG.PHILIPS LCD CO., LTD.
To: LG DISPLAY CO., LTD.
Reel/Frame 021763/0117 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 17, 2002
From: KIM, JAE BUM
To: LG.PHILIPS LCD CO., LTD.
Reel/Frame 013594/0139 →