Backlight unit, method of manufacturing the same and display apparatus including the same

Patent metadata

Field	Value
Publication number	US-11487158-B2
Application number	US-202117210025-A
Country	US
Kind code	B2
Filing date	Mar 23, 2021
Priority date	Mar 25, 2020
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A backlight unit includes a printed circuit board; a light source disposed on the printed circuit board and configured to emit light towards an upper side of the backlight unit; a reflective lens disposed on an upper side of the light source; and a reflective tape attached to the printed circuit board so as to surround the light source. At least a part of the reflective tape has a color different from a color of the light emitted by the light source.

First claim

What is claimed is:

1. A backlight unit comprising:
a printed circuit board;
a light source disposed on the printed circuit board and configured to emit light towards an upper side of the backlight unit;
a reflective lens disposed on an upper side of the light source; and
a reflective tape attached to the printed circuit board so as to surround the light source,
wherein at least a part of the reflective tape has a color different from a color of the light emitted by the light source,
wherein the reflective tape comprises:
a first conversion area that comprises a phosphor and is configured to increase brightness of a first portion of the light, and
a second conversion area that comprises an ink and is configured to decrease brightness of a second portion of the light, and

wherein the reflective tape, including the first conversion area and the second conversion area, is directly below the reflective lens.

2. The backlight unit according to claim 1 , wherein the reflective lens has a reflective surface which is positioned to face the printed circuit board and is formed concavely towards the printed circuit board.

3. The backlight unit according to claim 1 , wherein the light, that the light source is configured to emit, is blue light,
wherein the phosphor of the first conversion area is a yellow phosphor, and
wherein the second conversion area has a yellow color.

4. The backlight unit according to claim 3 , wherein the first conversion area and the second conversion area are formed as a plurality of dots disposed radially around a center of the reflective tape.

5. The backlight unit according to claim 1 , wherein the reflective tape is rotationally symmetrical around the light source.

6. The backlight unit according to claim 1 , wherein the reflective tape has a height lower than a height of the light source.

7. The backlight unit according to claim 1 , further comprising:
a reflective sheet attached to the printed circuit board so as to surround the reflective lens.

8. The backlight unit according to claim 7 , wherein the reflective sheet and the reflective tape are integrally formed as one body.

9. A method for manufacturing a backlight unit, the method comprising:
preparing a printed circuit board;
disposing a plurality of light sources on the printed circuit board to be spaced apart from each other;
attaching a reflective tape to a first area of the printed circuit board so as to surround the plurality of light sources;
disposing a reflective lens on an upper side of the plurality of light sources; and
attaching a reflective sheet to a second area of the printed circuit board,
wherein the reflective tape includes:
a first conversion area that includes a phosphor and is configured to increase brightness of a first portion of light from one of the plurality of light sources, and
a second conversion area that includes an ink and is configured to decrease brightness of a second portion of the light, and

wherein the reflective lens is disposed such that the reflective tape, including the first conversion area and the second conversion area, is directly below the reflective lens.

10. The method of claim 9 , wherein
the disposing the reflective lens comprises disposing the reflective lens on a light source from among the plurality of light sources such that a reflective surface of the reflective lens faces the printed circuit board and is formed concavely towards the printed circuit board.

11. The method of claim 9 , wherein
the plurality of light sources are configured to emit a blue light,
the phosphor of the first conversion area is a yellow phosphor, and
the second conversion area has a yellow color.

12. The method of claim 9 , wherein
the reflective tape and the reflective sheet are formed integrally as one body, and
the attaching the reflective tape and the attaching the reflective sheet are performed at a same time.

13. A display apparatus comprising:
a display panel; and
a backlight unit disposed on a lower side of the display panel,
wherein the backlight unit comprises:
a printed circuit board;
a light source disposed on the printed circuit board and configured to emit light towards an upper side of the backlight unit;
a reflective lens disposed on an upper side of the light source; and
a reflective tape attached to the printed circuit board so as to surround the light source,

wherein at least a part of the reflective tape has a color different from a color of the light emitted by the light source,
wherein the reflective tape comprises:
a first conversion area that comprises a phosphor and is configured to increase brightness of a first portion of the light, and
a second conversion area that comprises an ink and is configured to decrease brightness of a second portion of the light, and

wherein the reflective tape, including the first conversion area and the second conversion area, is directly below the reflective lens.

14. The display apparatus according to claim 13 , further comprising:
a quantum dot sheet disposed between the display panel and the backlight unit and configured to change a wavelength of the light.

15. The display apparatus according to claim 13 , wherein the reflective lens has a reflective surface which is positioned to face the printed circuit board and is formed concavely towards the printed circuit board.

16. The display apparatus according to claim 13 , wherein the light, that the light source is configured to emit, is blue light,
wherein the phosphor of the first conversion area is a yellow phosphor, and
wherein the second conversion area has a yellow color.

17. The display apparatus according to claim 16 , wherein the first conversion area and the second conversion area are formed as a plurality of dots disposed radially around a center of the reflective tape.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Hyungsuk
• Kim Jongbin
• Lee Youngmin
• Jeon Dukjin
• Cho Byoungjin
• Choi Sukju

Classifications

• G02F1/133603

  with LEDs · CPC title

• G02F1/133605 Primary

  including specially adapted reflectors · CPC title

• G02F1/133607

  the light controlling member including light directing or refracting elements, e.g. prisms or lenses · CPC title

• G02F1/133612 Primary

  Electrical details · CPC title

• G02F1/133606

  including a specially adapted diffusing, scattering or light controlling members · CPC title