DRIVE DEVICE OF COLOR LED BACKLIGHT

Abstract

Disclosed herein is a drive device of a color light emitting diode (LED) backlight, which is capable of uniformly controlling an optical output of an LED regardless of a variation in an ambient temperature and easily changing characteristic data (by referring to a lookup table).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram showing the configuration of a conventional drive device of a white LED backlight;

FIG. 2 is a block diagram showing the configuration of a drive device of a color LED backlight according to the present invention; and

FIG. 3 is a flowchart illustrating the operation of the drive device of the color LED backlight according to the present invention.

Claims

1. A drive device for driving a color light emitting diode (LED) backlight including a plurality of color LED arrays, comprising: a voltage detecting unit for detecting a voltage applied to the color LED backlight;a temperature detecting unit for detecting a temperature of the color LED backlight;a control unit for controlling driving currents which respectively flow in the color LED arrays of the color LED backlight according to the temperature detected by the temperature detecting unit and the voltage detected by the voltage detecting unit, by referring to previously set driving current values; anda multi-channel current source for adjusting amounts of the driving currents which respectively flow in the color LED arrays of the color LED backlight, by the driving current control of the control unit.

2. The device according to claim 1, wherein the control unit comprises: a lookup table in which the driving current values are previously set for each temperature and voltage;a main controller for uniformly controlling light efficiencies of the color LED arrays of the color LED backlight according to the temperature detected by the temperature detecting unit and the voltage detected by the voltage detecting unit by referring to the driving current values set in the lookup table; anda current controller for controlling the driving currents through the multi-channel current source by the control of the main controller.

3. The device according to claim 2, wherein: the plurality of color LED arrays of the color LED backlight include first, second and third color LED arrays; andthe multi-channel current source comprises a DA converter for converting a driving current control signal of the current controller of the control unit into an analog control signal; andfirst, second and third current sources for adjusting the amounts of first, second and third driving currents which respectively flow in the first, second and third color LED arrays, according to the analog control signal from the DA converter.