Warm white light emitting apparatus and back light module comprising the same

• US 7,906,789 B2
• Filed: 11/26/2008
• Issued: 03/15/2011
• Est. Priority Date: 07/29/2008
• Status: Active Grant

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Seoul Semiconductor Co., Ltd.
• Inventors: Jung, Jung Hwa, Lee, Sang Min
• Primary Examiner(s): DANG, TRUNG Q
• Application Number:
  US12/324,091
• Publication Number:
  US 20100025700A1
• Time in Patent Office: 839 Days
• Field of Search: 257/89, 257/98, 257/E33.001
• US Class Current: 257/89
• CPC Class Codes: F21K 9/62 using mixing chambers, e.g. housings with reflective walls
• CPC Class Codes: F21K 9/64 using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
• CPC Class Codes: F21V 23/009 the casing being inside the housing of the lighting device
• CPC Class Codes: F21V 7/26 the material comprising photoluminescent substances
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body

Abstract

A warm white light emitting apparatus includes a first light emitting diode (LED)-phosphor combination to generatea base light that is white or yellowish white and a second LED-phosphor combination to generate a Color Rendering Index (CRI) adjusting light. The base light the CRI adjusting light together make a warm white light having a color temperature of 2500 to 4500 K.

Claims

1. A warm white light emitting apparatus, comprising:

a first light emitting diode (LED)-phosphor combination to generate a base light, the base light being white or yellowish white; and

a second LED-phosphor combination to generate a Color Rendering Index (CRI) adjusting light,

wherein the base light and the CRI adjusting light together make a warm white light having a color temperature of 2500 to 4500K.

2. The warm white light emitting apparatus of claim 1, wherein the base light exists in a rectangular region defined by color coordinates (0.29, 0.45), (0.33, 0.37), (0.52, 0.47), and (0.45, 0.54) on a Commission on Illumination (CIE) chromaticity diagram, and the CRI adjusting light exists in a rectangular region defined by color coordinates (0.36, 0.34), (0.44, 0.20), (0.67, 0.32), and (0.55, 0.44) on the CIE chromaticity diagram.

3. The warm white light emitting apparatus of claim 1, wherein the first LED-phosphor combination comprises at least one blue LED and one or more phosphors having a peak wavelength of 500 to 600 nm.

4. The warm white light emitting apparatus of claim 3, wherein the second LED-phosphor combination comprises at least one blue LED and one or more phosphors having a peak wavelength greater than 600 nm.

5. The warm white light emitting apparatus of claim 3, wherein the second LED-phosphor combination comprises at least one ultra violet (UV) LED and one or more phosphors having a peak wavelength greater than 600 nm.

6. The warm white light emitting apparatus of claim 1, wherein the first LED-phosphor combination and the second LED-phosphor combination are disposed in a single package independently of each other.

7. The warm white light emitting apparatus of claim 6, wherein the first LED-phosphor combination and the second LED-phosphor combination are respectively positioned in corresponding cavities divided by a partition wall in the single package.

8. The warm white light emitting apparatus of claim 6, wherein corresponding phosphors in the first LED-phosphor combination and the second LED-phosphor combination are arranged to individually cover corresponding LEDs in the first LED-phosphor combination and the second LED-phosphor combination, respectively.

9. The warm white light emitting apparatus of claim 1, wherein a plurality of second LED-phosphor combinations are provided around the first LED-phosphor combination.

10. The warm white light emitting apparatus of claim 1, wherein the first LED-phosphor combination and the second LED-phosphor combination are contained in different packages, respectively.

11. The warm white light emitting apparatus of claim 10, further comprising a frame comprising a base portion having the different packages mounted thereon, and a reflective portion to reflect light generated from the first LED-phosphor combination and the second LED-phosphor combination.

12. The warm white light emitting apparatus of claim 1, wherein the LEDs in the first LED-phosphor combination and the second LED-phosphor combination operate individually.

13. The warm white light emitting apparatus of claim 1, wherein the first LED-phosphor combination comprises a blue LED and at least one of a blue phosphor, a green phosphor, and an amber phosphor.

14. The warm white light emitting apparatus of claim 1, wherein the second LED-phosphor combination comprises a blue or UV LED and at least one of a nitride-based red phosphor or a sulfide-based red phosphor.

15. A backlight module, comprising:

a light guide plate; and

a warm white light emitting apparatus to supply light to a side surface of the light guide plate,

wherein the warm white light emitting apparatus comprises a first light emitting diode (LED)-phosphor combination to generate a base light, the base light being white or yellowish white, and a second LED-phosphor combination to generate a Color Rendering Index (CRI) adjusting light,

wherein the base light and the CRI adjusting light together make a warm white light.

16. The backlight module of claim 15, wherein the warm white light emitting apparatus comprises an outer wall to define a space in which the first LED-phosphor combination and the second LED-phosphor combination are disposed, and a partition wall to separate the first LED-phosphor combination and the second LED-phosphor combination from each other, the outer wall being adjacent to the side surface of the light guide plate, the partition wall having a lower height than the outer wall to be spaced apart from the side surface of the light guide plate.

17. A warm white light emitting apparatus, comprising:

a first combination of a blue light emitting diode (LED) having a peak wavelength of 400 to 470 nm and at least one phosphor having a peak wavelength of 500 to 600 nm, the first combination to generate a base light, the base light being white or yellowish white; and

a second combination of a blue LED having a peak wavelength of 400 to 470 nm and at least one phosphor having a peak wavelength greater than 600 nm, the second combination to generate a Color Rendering Index (CRI) adjusting light,

wherein the base light and the CRI adjusting light together make a warm white light.

18. The warm white light emitting apparatus of claim 17, wherein the LED in the first combination comprises an alternating current (AC) LED, and the LED in the second combination comprises a direct current (DC) LED.

19. The warm white light emitting apparatus of claim 18, further comprising a delay phosphor.

20. The warm white light emitting apparatus of claim 18, further comprising at least one of an anti-total harmonic distortion (THD) circuit unit and an anti-flickering circuit unit.

21. The warm white light emitting apparatus of claim 18, wherein the LEDs in the first combination and the second combination are individually driven.

22. The warm white light emitting apparatus of claim 17, wherein the first combination and the second combination are disposed in a single package independently of each other.

23. The warm white light emitting apparatus of claim 17, wherein the first combination and the second combination are respectively positioned in corresponding cavities divided by a partition wall in a single package.

24. The warm white light emitting apparatus of claim 17, wherein the corresponding phosphors in the first combination and the second combination are provided to individually cover the corresponding LEDs in the first combination and the second combination, respectively.

25. The warm white light emitting apparatus of claim 17, wherein the first combination and the second combination are contained in different packages, respectively.

26. The warm white light emitting apparatus of claim 25, further comprising a frame comprising a base portion having the different packages mounted thereon and a reflective portion to reflect light generated from the first combination and the second combination.

27. A warm white light emitting apparatus, comprising:

a first combination of a blue light emitting diode (LED) having a peak wavelength of 400 to 470 nm and at least one phosphor having a peak wavelength of 500 to 600 nm, the first combination to generate a base light, the base light being white or yellowish white; and

a second combination of an ultra violet (UV) LED having a peak wavelength of 250 to 400 nm and at least one phosphor having a peak wavelength greater than 600 nm, the second combination to generate a Color Rendering Index (CRI) adjusting light,

wherein the base light and the CRI adjusting light together make a warm white light.

28. The warm white light emitting apparatus of claim 27, wherein the LED in the first combination comprises an alternating current (AC) LED, and the LED in the second combination comprises a direct current (DC) LED.

29. The warm white light emitting apparatus of claim 28, further comprising a delay phosphor.

30. The warm white light emitting apparatus of claim 28, further comprising at least one of an anti-THD circuit unit and an anti-flickering circuit unit.

31. The warm white light emitting apparatus of claim 28, wherein the LEDs in the first combination and the second combination are individually driven.

32. The warm white light emitting apparatus of claim 27, wherein the first combination and the second combination are disposed in a single package independently of each other.

33. The warm white light emitting apparatus of claim 27, wherein the first combination and the second combination are respectively positioned in corresponding cavities divided by a partition wall in a single package.

34. The warm white light emitting apparatus of claim 27, wherein the corresponding phosphors in the first combination and the second combination are provided to individually cover the corresponding LEDs in the first combination and the second combination, respectively.

35. The warm white light emitting apparatus of claim 27, wherein the first combination and the second combination are contained in different packages, respectively.

36. The warm white light emitting apparatus of claim 35, further comprising a frame comprising a base portion having the different packages mounted thereon and a reflective portion to reflect light generated from the first combination and the second combination.