Light emitting diode back light unit

• US 20070258266A1
• Filed: 05/08/2007
• Published: 11/08/2007
• Est. Priority Date: 05/08/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Baek, Chang Hoon, Lee, Sang Yun
• Granted Patent: US 7,874,715 B2
• Time in Patent Office: Days
• US Class Current: 362/612
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2360/145 the light originating from the display screen
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 3/3426 the different display panel areas being distributed in two dimensions, e.g. matrix

Abstract

A light emitting diode backlight (LED) unit includes: a substrate having a plurality of divided areas; a plurality of LEDs disposed on the substrate; and an LED driver supplying a drive power to the plurality of LEDs disposed in at least two of the plurality of divided areas, wherein at least a part of the plurality of LEDs disposed in one of the plurality of divided areas is electrically connected to each other.

Claims

1. A light emitting diode backlight unit comprising:

a substrate having a plurality of divided areas;

a plurality of light emitting diodes disposed on the substrate; and

a light emitting diode driver supplying a drive power to the plurality of light emitting diodes disposed in at least two of the plurality of divided areas,

wherein at least a part of the plurality of light emitting diodes disposed in one of the plurality of divided areas is electrically connected to each other.

2. The light emitting diode backlight unit of claim 1, further comprising:

a sensor portion detecting an amount of light emitted by the plurality of light emitting diodes; and

a controller comparing the light amount detected by the sensor portion with a previously determined reference light amount and controlling the drive power supplied to the plurality of light emitting diodes according to a result of the comparison.

3. The light emitting diode backlight unit of claim 1, wherein the plurality of light emitting diodes comprises:

a plurality of red light emitting diodes emitting red light;

a plurality of green light emitting diodes emitting green light; and

a plurality of blue light emitting diodes emitting blue light,

wherein mutual electrical connection is formed between light emitting diodes whose color of lights are identical with each other.

4. The light emitting diode backlight unit of claim 3, wherein the light emitting diode driver comprises:

a red light emitting diode drive circuit supplying a drive power to the plurality of red light emitting diodes;

a green light emitting diode drive circuit supplying a drive power to the plurality of green light emitting diodes; and

a blue light emitting diode drive circuit supplying a drive power to the plurality of blue light emitting diodes.

5. The light emitting diode backlight unit of claim 2, wherein the light emitting diode driver comprises a pulse with modulation driving portion determining a size of the drive power supplied to the light emitting diodes by switching a power supply on/off and the controller controls the drive power by determining an on/off switching duty ratio of the pulse with modulation driving portion.