Backlight modules using diffraction optical elements

• US 20060147152A1
• Filed: 06/17/2005
• Published: 07/06/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Lu, Ying-Tsung, Lai, Pong, Chu, Chang-Sheng, Wu, Ching-Chin
• Granted Patent: US 7,251,412 B2
• Time in Patent Office: Days
• US Class Current: 385/37
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

Direct backlight modules using diffraction optical elements are provided. A direct backlight module includes a light source and a diffraction optical element, wherein the diffraction optical element is disposed above the light source. By properly arranging the phase function, the diffraction optical element can substantially modulate the wavefront of the light emitted from the light source and control light distribution as well as light direction.

Claims

1. A backlight module, comprising:

a light source; and

a diffraction optical element disposed above the light source.

2. The backlight module as claimed in claim 1, wherein the light source is a light-emitting diode, fluorescent lamp, laser diode.

3. The backlight module as claimed in claim 1, wherein the diffraction optical element is a transparent diffraction optical element, or a reflective diffraction optical element.

4. The backlight module as claimed in claim 1, wherein the diffraction optical element modulates the light direction and the light phase distribution

5. The backlight module as claimed in claim 1, wherein the diffraction optical element comprises plastic, silica, or metal.

6. The backlight module as claimed in claim 1, wherein the diffraction optical element is made by injection molding, rolling, or a stamping process.

7. The backlight module as claimed in claim 1, wherein the diffraction optical element can be combined with, or formed on a refraction optical element.