Backlight unit of liquid crystal display

• US 7,172,325 B2
• Filed: 08/12/2004
• Issued: 02/06/2007
• Est. Priority Date: 05/28/2004
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Park, Young Sam, Kim, Hyung Suk, Jeong, Young June, Hahm, Hun Joo, Park, Jung Kyu
• Primary Examiner(s): O'Shea; Sandra
• Assistant Examiner(s): Truong; Bao Q.
• Application Number:
  US10/916,480
• Publication Number:
  US 20050276066A1
• Time in Patent Office: 908 Days
• Field of Search: 362/561, 362/555, 362/227, 362/230, 362/231, 362/235, 362/236, 362/237, 362/238, 362/240, 362/241, 362/245, 362/247, 362/294, 362/373, 362/800, 362/308, 362/309, 362/330, 362/335, 362/559, 362/560, 257/98
• US Class Current: 362/561
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133605 including specially adapted reflectors
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A backlight unit of a liquid crystal display includes a plurality of light emitting diode packages arranged in a matrix while being spaced a uniform distance apart from each other. Each light emitting diode package includes one or more light emitting diode chips and is structured such that light generated from the light emitting chips is emitted in the horizontal direction. A reflector consists of a plurality of reflection cells connected to each other in a matrix. Each of the reflection cells of a unit size has each of the light generating packages positioned at the center thereof, and reflects the light, emitted from the light emitting diode at the center thereof in the horizontal direction, in the vertical direction.

Claims

1. A backlight unit of a liquid crystal display, comprising:

a plurality of light emitting diode packages arranged in a matrix while being spaced a uniform distance apart from each other, each of said light emitting diode packages including one or more light emitting diode chips and being structured such that light generated from the one or more light emitting diode chips is emitted in the horizontal direction; and

a reflector comprising a plurality of reflection cells connected to each other in a matrix, wherein each of the reflection cells has one of the light emitting diode packages positioned at the center thereof, and reflects the light, emitted from the light emitting diode package at the center thereof in the horizontal direction, in the vertical direction;

wherein each of the light emitting diode packages comprises;

a printed circuit board with a conductive pattern for transmitting power formed thereon;

a base located on the printed circuit board and having a heat dissipation function for transmitting heat to the printed circuit board;

the one or more light emitting diode chips mounted on the base and electrically connected to the conductive pattern of the printed circuit board; and

a lens formed on the base in order to change a path of the light, generated from the one or more light emitting diode chips, to the horizontal direction.

2. The backlight unit as set forth in claim 1, wherein each of the reflection cells of the reflector is formed, at the center thereof, with a hole having a predetermined size, and the light emitting diode package of said reflection cell is inserted into the hole.

3. The backlight unit as set forth in claim 1, wherein the one or more light emitting diode chips of each of said light emitting diode packages consist of white light emitting diodes.

4. The backlight unit as set forth in claim 1, wherein the one or more light emitting diode chips of each of said light emitting diode packages consist of a combination of light emitting diodes emitting light of complementary colors.

5. The backlight unit as set forth in claim 1, wherein the lens comprises a reflective surface having a spherical surface shape, at an upper portion of the lens in the vertical direction above the one or more light emitting diode chips, and

said reflective surface reflecting the light, emitted from the one or more light emitting diode chips in the vertical direction, in the horizontal direction.

6. The backlight unit as set forth in claim 5, wherein the reflective surface of the lens is defined by a reflective material coating on an upper surface of the lens, said upper surface having the spherical surface shape.

7. A backlight unit of a liquid crystal display, comprising a plurality of unit backlight cells connected to each other in a matrix, each of the plurality of unit backlight cells integrally comprising:

a printed circuit board having a conductive pattern for transmitting power formed thereon;

one or more light emitting diode chips electrically connected to the conductive pattern on the printed circuit board;

a lens for changing a path of light generated from the one or more light emitting diode chips to the horizontal direction; and

a reflector formed to surround the lens and having a unit size for reflecting the light refracted into the horizontal direction by the lens in the vertical direction.

8. The backlight unit as set forth in claim 7, wherein the lens comprises a reflective surface having a spherical surface shape, at an upper portion of the lens in the vertical direction above the one or more light emitting diode chips, and

said reflective surface reflecting the light, emitted from the one or more light emitting diode chips in the vertical direction, in the horizontal direction.

9. The backlight unit as set forth in claim 8, wherein the reflective surface of the lens is defined by a reflective material coating on an upper surface of the lens, said upper surface having the spherical surface shape.

10. The backlight unit as set forth in claim 7, wherein the one or more light emitting diode chips consist of white light emitting diodes.

11. The backlight unit as set forth in claim 7, wherein the one or more light emitting diode chips consist of a combination of light emitting diodes emitting light of complementary colors.