WHITE LIGHT LED

• US 20090033204A1
• Filed: 01/30/2008
• Published: 02/05/2009
• Est. Priority Date: 08/03/2007
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Chi, Wu-sheng, Wang, Chih-lin
• Granted Patent: US 7,872,409 B2
• Time in Patent Office: Days
• US Class Current: 313/498
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/502 Wavelength conversion materials

Abstract

A white light LED is disclosed. The white light LED includes a dual-wavelength chip and an optical thin film. The dual-wavelength chip generates a first wavelength light and a second wavelength light. The optical thin film is disposed above the dual-wavelength chip. The optical thin film can partially be a quantum well thin film. Therefore, the quantum well thin film can be excited by the first wavelength light and/or second wavelength light to generate a third wavelength light. The optical thin film further comprises a plurality of windows to let the first and second wavelength lights pass through. By predetermining a ratio of the quantum well thin film area and the window area that belong to the optical thin film, a lumen ratio of the first, the second, and the third wavelength lights can be adjusted to realize white lights of different color temperatures.

Claims

1. A light emitting diode, comprising:

a dual-wavelength chip for generating a first wavelength light and a second wavelength light; and

an optical thin film, disposed above the dual-wavelength chip, for receiving at least one of the first wavelength light and the second wavelength light so as to generate a third wavelength light to mix with the first wavelength light, the second wavelength light, and the third wavelength light to produce a monochromatic light.

2. The light emitting diode according to claim 1, wherein the first wavelength light is a blue light having a wavelength of 450 nm to 460 nm.

3. The light emitting diode according to claim 1, wherein the second wavelength light is a green light having a wavelength of 520 nm to 540 nm.

4. The light emitting diode according to claim 1, wherein the third wavelength light is a red light having a wavelength of 620 nm to 630 nm.

5. The light emitting diode according to claim 1, wherein the monochromatic light is a white light.

6. The light emitting diode according to claim 5, wherein a lumen ratio of the first wavelength light, the second wavelength light, and the third wavelength light is adjustable to realize the white light of different color temperatures.

7. The light emitting diode according to claim 6, wherein the lumen ratio satisfies the following equation:

the first wavelength light;

the second wavelength light;

the third wavelength light=

1;

1;

y;

x; and

y=1.67x+4.8

8. The light emitting diode according to claim 1, wherein the optical thin film is a thin film having quantum well structures.

9. The light emitting diode according to claim 8, wherein the thin film further comprises a plurality of windows to let the first and second wavelength lights pass through.

10. The light emitting diode according to claim 9, wherein a lumen ratio of the first wavelength light, the second wavelength light and the third wavelength light is adjusted by predetermining a square measure proportion of the windows to the quantum well structures.

11. A backlight module a liquid crystal display, comprising the light emitting diode of claim 1.

12. A method of manufacturing a light emitting diode, comprising:

providing a dual-wavelength chip for generating a first wavelength light and a second wavelength light; and

disposing an optical thin film above the dual-wavelength chip for receiving at least one of the first wavelength light and the second wavelength light so as to generate a third wavelength light, wherein the first wavelength light, the second wavelength light, and the third wavelength light are mixed to produce a monochromatic light.

13. The method according to claim 12, wherein the monochromatic light is a white light.

14. The method according to claim 13, further comprising adjusting a lumen ratio of the first wavelength light, the second wavelength light and the third wavelength light so as to realize the white light of different color temperatures.

15. The method according to claim 14, wherein the lumen ratio satisfies the following equation:

the first wavelength light;

the second wavelength light;

the third wavelength light=

1;

1;

y;

x; and

y=1.67x+4.8

16. The method according to claim 12, wherein the optical thin film is a thin film having quantum well structures.

17. The method according to claim 16, wherein the thin film further comprises a plurality of windows to let the first and second wavelength lights pass through.

18. The method according to claim 17, further comprising adjusting a lumen ratio of the first wavelength light, the second wavelength light and the third wavelength light by predetermining a square measure proportion of the windows to the quantum well structures.