Backlight unit

• US 8,220,944 B2
• Filed: 10/08/2010
• Issued: 07/17/2012
• Est. Priority Date: 07/19/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Jeong, Young June, Kim, Dae Yeon, Hahm, Hun Joo, Shin, Jae Hong, Shin, Chang Ho
• Primary Examiner(s): Husar, Stephen F
• Application Number:
  US12/901,236
• Publication Number:
  US 20110026241A1
• Time in Patent Office: 648 Days
• Field of Search: 362 971- 973, 362/249.02, 362/249.05, 362/249.06, 362/612, 362/613, 313/500
• US Class Current: 362/97.3
• 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: F21K 9/60 Optical arrangements integrated in the light source, e.g. for improving the colour rendering index or the light extraction
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: H05K 1/142 Arrangements of planar printed circuit boards in the same plane, e.g. auxiliary printed circuit insert mounted in a main printed circuit

Abstract

Provided is a backlight unit including a plurality of light emitting diodes (LEDs) that emit light; a plurality of LED modules having a printed circuit board (PCB) which supports and drives the plurality of LEDs; a plurality of optical sheets that are attached to the top surfaces of the respective LED modules; and a plurality of heat radiating pads that are attached to the rear surfaces of the respective LED modules.

Claims

1. A backlight unit comprising:

a plurality of light emitting diodes (LEDs) that emit light;

a plurality of LED modules having a printed circuit board (PCB) which supports and drives the plurality of LEDs;

a plurality of optical sheets that are attached to top surfaces of the plurality of LED modules, respectively,

wherein the plurality of LED modules include a plurality of white LEDs arranged in a matrix shape composed of two or more rows and two or more columns and a center luminous intensity of an LED unit composed of arbitrary LEDs which are disposed at the shortest distance from each other corresponds to 80 to 120% of the average of luminous intensities of the LEDs, and

each of the LEDs has a phosphor in order to emit white light.

2. The backlight unit according to claim 1, wherein the plurality of LEDs are continuously arranged in a triangle shape and a distance between first and second LEDs, which are disposed in the same column and are adjacent to each other, is set in the range of 20 to 140 mm.

3. The backlight unit according to claim 1, wherein the plurality of LEDs are continuously arranged in a triangle shape and a distance between LEDs which are adjacent to each other in a row or column direction is set in the range of 8.2 to 70 mm.

4. The backlight unit according to claim 1, wherein the plurality of LEDs are continuously arranged in a rectangle shape and distances between LEDs, which are adjacent to each other, are set in the range of 8.2 to 70 mm.

5. The backlight unit according to claim 1, wherein the plurality of LEDs are continuously arranged in a rectangle shape and an angle between the column direction where the LEDs are arranged and a position where the LED is disposed is formed in the range of 70 to 110 degrees.

6. The backlight unit according to claim 1, wherein the plurality of LED modules are divided into a plurality of blocks which are separated from each other through printing circuit patterns in a circuit manner so as to be independently turned on/off.

7. A backlight unit comprising:

a plurality of light emitting diodes (LEDs) that emit white light; and

a plurality of LED modules having a printed circuit board (PCB) which supports and drives the plurality of LEDs,

wherein distances between LEDs, which are adjacent to each other, are set in the range of 8.2 to 70 mm,

the plurality of LED modules are arranged outside of a predetermined region of a central part of the backlight unit, and

the plurality of LED modules emit white light towards the central part.