Patent ID: 8077137
Filing Date: 2011-12-13
Classification: G09G

Abstract:
1. A liquid crystal display backlight driving system using at least one red light emitting diode (LED) array with a plurality of red LEDs emitting red light connected in series, at least one green LED array with a plurality of green LEDs emitting green light connected in series, and at least one blue LED array with a plurality of blue LEDs emitting blue light connected in series as light sources, comprising: a switch mode power supply (SMPS) having an AC-DC converter for converting an externally inputted AC voltage to a DC voltage, a red LED DC-DC converter for converting the DC voltage, converted from the AC-DC converter, to a predetermined magnitude of DC voltage suitable for driving the red LED array, a green LED DC-DC converter for converting the DC voltage, converted from the AC-DC converter, to a predetermined magnitude of DC voltage suitable for driving the green LED array, and a blue LED DC-DC converter for converting the DC voltage, converted from the AC-DC converter, to a predetermined magnitude of DC voltage suitable for driving the blue LED array, wherein all of the same color LED arrays are operated commonly by a single DC-DC converter; a light source disposed on a substrate where the red, green and blue LED arrays are arranged, the light source having at least one of each of red, green and blue LED constant current controllers for controlling the current running through the red, green and blue LED arrays so as to maintain predetermined outputs from the red, green and blue LEDs; and a bridge board having circuit patterns for electrically connecting the red, green and blue LED DC-DC converters with the red, green and blue LED constant current controllers, respectively, wherein the bridge board does not have any electronic devices mounted thereon.