Plane light source and LCD backlight unit having the same

• US 7,894,017 B2
• Filed: 08/27/2008
• Issued: 02/22/2011
• Est. Priority Date: 08/30/2007
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung LED Co., Ltd. (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Hyung Suk, Jeong, Young June, Han, Seong Yeon, Park, Young Sam, Yoo, Chul Hee, Hahm, Hun Joo
• Primary Examiner(s): KIANNI, KAVEH C
• Application Number:
  US12/199,327
• Publication Number:
  US 20090059123A1
• Time in Patent Office: 909 Days
• Field of Search: 349/69, 349/64
• US Class Current: 349/69
• CPC Class Codes: G02F 1/133603 with LEDs

Abstract

There are provided a plane light source and an LCD backlight unit having the same. A plane light source including light emitting device matrixes each having a plurality of light emitting devices arranged in rows and columns on a substrate according to an aspect of the invention includes: a first matrix having a plurality of light emitting devices arranged in rows and columns; and a second matrix having a plurality of light emitting devices arranged in rows and columns, the light emitting devices each located within a rectangle formed by four adjacent light emitting devices included in the first matrix, and forming angles θ satisfying the condition of 45°≦θ≦55° therebetween on the basis of a horizontal direction, wherein among pitches between one light emitting devices included in the light emitting device matrixes and another lighting light emitting device adjacent to the light emitting device, a pitch P1 between the light emitting device and the light emitting device diagonally across from the light emitting device satisfies the condition of 25 mm≦P1≦29 mm, and a pitch P2 between the light emitting device and another light emitting device located in a horizontal direction satisfies the condition of 34 mm≦P2≦38 mm.

Claims

1. An LCD backlight unit comprising:

a plane light source including light emitting device matrixes each having a plurality of light emitting devices arranged in rows and columns on a substrate, the plane light source comprising;

a first matrix having a plurality of light emitting devices arranged in rows and columns; and

a second matrix having a plurality of light emitting devices arranged in rows and columns, the light emitting devices each located within a rectangle formed by four adjacent light emitting devices included in the first matrix, and forming angles θ

satisfying the condition of 45°

≦

θ

≦

55°

therebetween on the basis of a horizontal direction,

wherein among pitches between one light emitting devices included in the light emitting device matrixes and another lighting light emitting device adjacent to the light emitting device, a pitch P1 between the light emitting device and the light emitting device diagonally across from the light emitting device satisfies the condition of 25 mm≦

P1≦

29 mm, and a pitch P2 between the light emitting device and another light emitting device located in a horizontal direction satisfies the condition of 34 mm≦

P2≦

38 mm,

a diffusion sheet located above the plane light source and uniformly diffusing light incident from the plane light source; and

at least one light collecting sheet located above the diffusion sheet and collecting light diffused by the diffusion sheet in a direction perpendicular to the plane of the LCD panel.

2. The LCD backlight unit of claim 1, wherein each of the light emitting devices included in the second matrix is located at the center of the rectangle.

3. The LCD backlight unit of claim 1, wherein the light emitting device emits white light.

4. The LCD backlight unit of claim 1, further comprising a diffusion sheet disposed along a light emission path of the light emitting devices.

5. The LCD backlight unit of claim 1, wherein the light emitting device is a light emitting diode (LED).