White light emitting device and white light source module using the same

• US 8,317,348 B2
• Filed: 04/29/2011
• Issued: 11/27/2012
• Est. Priority Date: 12/05/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Yoo, Chul Hee, Jeong, Young June, Park, Young Sam, Han, Seong Yeon, Kim, Ho Yeon, Hahm, Hun Joo, Kim, Hyung Suk
• Primary Examiner(s): SEMBER, THOMAS M
• Application Number:
  US13/097,419
• Publication Number:
  US 20110242437A1
• Time in Patent Office: 578 Days
• Field of Search: 362 971- 973, 362/84, 362/293, 257 98-100, 257/E33.061, 313502-504, 313485-487
• US Class Current: 362/84
• CPC Class Codes: C09K 11/0883 Arsenides; Nitrides; Phosphides
• CPC Class Codes: C09K 11/7731 with alkaline earth metals
• CPC Class Codes: C09K 11/77347 Silicon Nitrides or Silicon Oxynitrides
• CPC Class Codes: C09K 11/77348 Silicon Aluminium Nitrides or Silicon Aluminium Oxynitrides
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H05B 33/12 Light sources with substantially two-dimensional radiating surfaces
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

A white light emitting device including: a blue light emitting diode chip having a dominant wavelength of 443 to 455 nm; a red phosphor disposed around the blue light emitting diode chip, the red phosphor excited by the blue light emitting diode chip to emit red light; and a green phosphor disposed around the blue light emitting diode chip, the green phosphor excited by the blue light emitting diode chip to emit green light, wherein the red light emitted from the red phosphor has a color coordinate falling within a space defined by four coordinate points (0.5448, 0.4544), (0.7079, 0.2920), (0.6427, 0.2905) and (0.4794, 0.4633) based on the CIE 1931 chromaticity diagram, and the green light emitted from the green phosphor has a color coordinate falling within a space defined by four coordinate points (0.1270, 0.8037), (0.4117, 0.5861), (0.4197, 0.5316) and (0.2555, 0.5030) based on the CIE 1931 color chromaticity diagram.

Claims

1. A white light source module comprising:

a blue light emitting diode having a dominant wavelength of 443 to 455 nm; and

a first phosphor and a second phosphor disposed around the blue light emitting diode, the first phosphor and the second phosphor excited by the blue light emitting diode to emit white light together with a blue light emitted by the blue light emitting diode;

wherein the light emitted from the first phosphor has a color coordinate falling within a space defined by four coordinate points (0.5448, 0.4544), (0.7079, 0.2920), (0.6427, 0.2905) and (0.4794, 0.4633) based on the CIE 1931 color chromaticity diagram.

2. The white light source module of claim 1, wherein the first phosphor is a red phosphor excited by the blue light emitting diode to emit red light.

3. The white light source module of claim 2, wherein the first phosphor is a nitride or a sulfide.

4. The white light source module of claim 1 or claim 2, wherein the second phosphor is a green phosphor excited by the blue light emitting diode to emit green light.

5. The white light source module of claim 4, wherein the second phosphor is a silicate or .beta.-sialon.

6. A display device comprising:

a display panel; and

a backlight unit which emits light to the display panel, the backlight unit comprising a white light source module, wherein the white light source module comprises;

a blue light emitting diode having a dominant wavelength of 443 to 455 nm; and

a first phosphor and a second phosphor disposed around the blue light emitting diode, the first phosphor and the second phosphor excited by the blue light emitting diode to emit white light together with a blue light emitted by the blue light emitting diode;

wherein the light emitted from the first phosphor has a color coordinate falling within a space defined by four coordinate points (0.5448, 0.4544), (0.7079, 0.2920), (0.6427, 0.2905) and (0.4794, 0.4633) based on the CIE 1931 color chromaticity diagram.

7. The display device of claim 6, further comprising a driving circuit which drives the backlight unit.

8. The display device of claim 6, wherein the display panel is a liquid crystal panel.

9. A television comprising the display device of claim 6.

10. A white light source module comprising:

a blue light emitting diode having a dominant wavelength of 443 to 455 nm; and

a first phosphor and a second phosphor disposed around the blue light emitting diode, the first phosphor and the second phosphor excited by the blue light emitting diode to emit white light together with a blue light emitted by the blue light emitting diode;

wherein the light emitted from the first phosphor has a color coordinate falling within a space defined by four coordinate points (0.1270, 0.8037), (0.4117, 0.5861), (0.4197, 0.5316) and (0.2555, 0.5030) based on the CIE 1931 color chromaticity diagram.

11. The white light source module of claim 10, wherein the first phosphor is a green phosphor excited by the blue light emitting diode to emit green light.

12. The white light source module of claim 11, wherein the first phosphor is a silicate or .beta.-sialon.

13. The white light source module of claim 11 or 12, wherein the second phosphor is a red phosphor excited by the blue light emitting diode to emit red light.

14. The white light source module of claim 13, wherein the second phosphor is a nitride or a sulfide.

15. A display device comprising:

a display panel; and

a backlight unit which emits light to the display panel, the backlight unit comprising a white light source module, wherein the white light source module comprises;

a blue light emitting diode having a dominant wavelength of 443 to 455 nm; and

a first phosphor and a second phosphor disposed around the blue light emitting diode, the first phosphor and the second phosphor excited by the blue light emitting diode to emit white light together with a blue light emitted by the blue light emitting diode;

wherein the light emitted from the first phosphor has a color coordinate falling within a space defined by four coordinate points (0.1270, 0.8037), (0.4117, 0.5861), (0.4197, 0.5316) and (0.2555, 0.5030) based on the CIE 1931 color chromaticity diagram.

16. The display device of claim 15, further comprising a driving circuit which drives the backlight unit.

17. The display device of claim 15, wherein the display panel is a liquid crystal panel.

18. A television comprising the display device of claim 15.

19. A white light source module comprising:

a blue light emitting diode chip having a dominant wavelength of 443 to 455 nm;

a first phosphor;

and a second phosphor, wherein the light emitted from the first phosphor has a color coordinate falling within a space defined by four coordinate points (0.5448, 0.4544), (0.7079, 0.2920), (0.6427, 0.2905) and (0.4794, 0.4633) based on the CIE 1931 color chromaticity diagram, and the light emitted from the second phosphor has a color coordinate falling within a space defined by four coordinate points (0.1270, 0.8037), (0.4117,

     5861), (0.4197, 0.5316) and (0.2555, 0.5030) based on the CIE 1931 color chromaticity diagram; and

wherein the first phosphor and the second phosphor are provided in a film.

20. The white light source module of claim 19, wherein the film is disposed on the blue light emitting diode chip.

21. The white light source module of claim 19 further comprising an encapsulant which encloses the blue light emitting diode chip, wherein the film is disposed on a surface of the encapsulant.

22. The white light source module of claim 21, further comprising a circuit board, wherein the blue light emitting diode chip is disposed directly on the circuit board, the encapsulant forms a dome-shape surrounding the blue light emitting diode chip, and the film disposed on the surface of the encapsulant is disposed to cover an outer dome-shaped surface of the encapsulant.

23. The white light source module of claim 21, further comprising a circuit board and package body defining a reflective cup mounted on the circuit board, wherein the blue light emitting diode chip is mounted within the reflective cup of the package body, the encapsulant is disposed within the reflective cup, and the film disposed on the surface of the encapsulant is disposed on an upper, substantially planar surface of the encapsulant.

24. A display device comprising:

a display panel; and

a backlight unit which emits light to the display panel, the backlight unit comprising a white light source module, wherein the white light source module comprises a blue light emitting diode chip having a dominant wavelength of 443 to 455 nm;

a first phosphor; and

a second phosphor, wherein the light emitted from the first phosphor film has a color coordinate falling within a space defined by four coordinate points (0.5448, 0.4544), (0.7079, 0.2920), (0.6427, 0.2905) and (0.4794, 0.4633) based on the CIE 1931 color chromaticity diagram, and the light emitted from the second phosphor film has a color coordinate falling within a space defined by four coordinate points (0.1270, 0.8037), (0.4117, 0.5861), (0.4197, 0.5316) and (0.2555, 0.5030) based on the CIE 1931 color chromaticity diagram; and

wherein the first phosphor and the second phosphor are provided in a film.

25. The display device of claim 24, further comprising a driving circuit which drives the backlight unit.

26. The display device of claim 24, wherein the display panel is a liquid crystal panel.

27. A television comprising the display device of claim 24.