White light emitting device and display device using the same

• US 10,545,375 B2
• Filed: 12/03/2015
• Issued: 01/28/2020
• Est. Priority Date: 12/03/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jeon, Jong Pil, Kim, Jong-hoi, Lee, Kye Hoon, Lee, Dae-hee, Cho, Byoung-jin, Choi, Suk-ju
• Primary Examiner(s): Caley, Michael H
• Assistant Examiner(s): Qureshi, Mariam
• Application Number:
  US14/958,453
• Publication Number:
  US 20160161089A1
• Time in Patent Office: 1,517 Days
• 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: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: H01L 2224/1403 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation

Abstract

A white light emitting device, including a circuit board; a plurality of light sources mounted on the circuit board, each light source of the plurality of light sources configured to emit monochromatic light; a light converter spaced apart from the circuit board, the light converter configured to convert the monochromatic light emitted from the light sources to white light; and a compensator provided between the circuit board and the light converter, the compensator configured to convert the emitted monochromatic light to white light.

Claims

1. A white light emitting device comprising:

a circuit board;

a plurality of light sources mounted on the circuit board, each light source of the plurality of light sources including a light emitting diode configured to emit blue light, and a lens disposed directly on the circuit board and through which the blue light emitted from the light emitting diode passes;

a light converter spaced apart from the circuit board, the light converter configured to emit approximately white light in response to the blue light being incident on the light converter;

a compensator provided on the circuit board, at least partially covered by the lens and spaced apart from the lens and the light emitting diode, the compensator configured to emit approximately white light in response to the blue light being incident on the compensator,

wherein the compensator includes a plurality of yellow phosphor members, the plurality of yellow phosphor members are arranged at regular intervals on a circumference of approximately a circle surrounding the light emitting diode, and each of the plurality of yellow phosphor members is arranged at an interval corresponding to a predetermined angle around the light emitting diode.

2. The white light emitting device according to claim 1, wherein the plurality of yellow phosphor members are disposed between the plurality of light sources.

3. The white light emitting device according to claim 1, wherein at least one yellow phosphor member of the plurality of yellow phosphor members is disposed inside at least one light source of the plurality of light sources.

4. The white light emitting device according to claim 3, wherein the at least one yellow phosphor member is disposed between the light emitting diode and the lens emits approximately white light in response to a light reflected inside of the at least one light source being incident.

5. The white light emitting device according to claim 1, wherein the plurality of yellow phosphor members have different patterns according to different patterns of a color mura of the white light emitted from the light converter.

6. The white light emitting device according to claim 1, wherein the plurality of yellow phosphor members include a first group of yellow phosphor members disposed on an edge of the circuit board, and a second group of yellow phosphor members disposed at a center of the circuit board, and the first group is more densely arranged than the second group.

7. The white light emitting device according to claim 1, wherein the plurality of yellow phosphor members have different sizes according to different levels of a color mura of white light converted from the light converter.

8. The white light emitting device according to claim 7, wherein the plurality of yellow phosphor members includes a first yellow phosphor member having first size and located on an edge of the circuit board and a second yellow phosphor member having a second size and located on a center of the circuit board, and the first size is greater than the second size.

9. The white light emitting device according to claim 1, further comprising:

a coated layer stacked on the compensator.

10. The white light emitting device according to claim 1, further comprising:

a reflector including a plurality of openings corresponding to the plurality of light sources, stacked on the circuit board, and reflecting the blue light toward the light converter.

11. The white light emitting device of claim 1, wherein the compensator is a planar sheet or planar film disposed on the circuit board.

12. The white light emitting device of claim 1, wherein the plurality of yellow phosphor members are arranged at approximately equal intervals on the circumference of approximately the circle.

13. A white light emitting device comprising:

a circuit board;

a plurality of light sources mounted on the circuit board, each light source of the plurality of light sources including a light emitting diode configured to generate blue light, and a lens disposed directly on the circuit board and through which the blue light emitted from the light emitting diode passes;

a light converter spaced apart from the circuit board, the light converter configured to emit approximately white light in response to the blue light being incident on the light converter;

a reflective sheet stacked on the circuit board, the reflective sheet configured to reflect the blue light toward the light converter; and

a compensator provided on the circuit board at least partially covered by the lens and spaced apart from the lens and the light emitting diode, the compensator configured to emit approximately white light in response to the blue light being incident on the compensator,

wherein the compensator includes a plurality of yellow phosphor members, the plurality of yellow phosphor members are arranged substantially equidistant from the light emitting diode, and each of the plurality of yellow phosphor members is arranged at an interval corresponding to a predetermined angle around the light emitting diode.

14. The white light emitting device according to claim 13, wherein the plurality of yellow phosphor members are arranged between the plurality of light sources.

15. The white light emitting device according to claim 14, wherein the plurality of yellow phosphor members have different patterns according to different patterns of a color mura of the white light converted from the light converter.

16. The white light emitting device according to claim 15, wherein the plurality of yellow phosphor members includes a first group of yellow phosphor members disposed on an edge of the circuit board, and a second group of yellow phosphor members disposed at a center of the circuit board, and the first group is more densely arranged than the second group.

17. The white light emitting device according to claim 13, wherein the plurality of yellow phosphor members are directly printed and formed on the reflective sheet.

18. The white light emitting device according to claim 13, wherein the plurality of yellow phosphor members are disposed between the lens and the light emitting diode.

19. The white light emitting device according to claim 14, wherein the compensator is formed of at least one from among a sheet or film having the plurality of yellow phosphor members, and the compensator is bonded to the reflective sheet.

20. The white light emitting device according to claim 14, wherein the compensator is formed by depositing the plurality of yellow phosphor members on the reflective sheet.

21. The white light emitting device according to claim 14, wherein the compensator is formed by bonding the plurality of yellow phosphor members to the reflective sheet.

22. The white light emitting device of claim 13, wherein the plurality of yellow phosphor members are arranged at approximately equal intervals on a circumference of approximately a circle with the light emitting diode as a center.

23. A display apparatus, comprising:

a display panel;

a diffusion plate provided behind the display panel; and

a light emitting device provided behind the diffusion plate, the light emitting device configured to emit light onto the diffusion plate,

wherein the light emitting device comprises;

a circuit board;

a plurality of light sources mounted on the circuit board, each light source of the plurality of light sources including a light emitting diode configured to emit blue light and a lens through which the blue light emitted from the light emitting diode passes;

a light converter spaced apart from the circuit board, the light converter configured to emit approximately white light in response to the blue light being incident on the light converter; and

a compensator, formed of a material having a yellow color, provided on the circuit board to be closer to the circuit board than the lens and to at least partially surround the light emitting diode,

wherein the compensator includes a plurality of yellow phosphor members, the plurality of yellow phosphor members are arranged at regular intervals on a circumference of approximately a circle, and each of the plurality of yellow phosphor members is arranged at an interval corresponding to a predetermined angle around the light emitting diode.

24. The display apparatus of claim 23, wherein the compensator is disposed on the circuit board between the lens and the light emitting diode.

25. The display apparatus of claim 23, wherein a yellow phosphor member of the plurality of yellow phosphor members is formed in a rectangular shape.

26. The display apparatus of claim 23, wherein a part of one phosphor yellow member of the plurality of yellow phosphor members is disposed inside one light source of the plurality of light sources, and another part of the one yellow phosphor member of the plurality of yellow phosphor members is disposed outside the one light source of the plurality of light sources.

27. The display apparatus of claim 23, wherein the compensator is disposed in parallel with the circuit board.

28. The display apparatus of claim 23, further comprising a coated layer stacked on the compensator,

wherein the coated layer is provided in a rear of the lens, and

the compensator is provided between the circuit board and the coated layer.

29. The display apparatus of claim 23, wherein the lens is disposed directly on the compensator, and the compensator is disposed directly on the circuit board.

30. The display apparatus of claim 23, wherein the plurality of yellow phosphor members are arranged at approximately equal intervals on the circumference of approximately the circle.

31. The display apparatus of claim 23, wherein the plurality of yellow phosphor members are formed by printing or coating on the circuit board.