Patent ID: 7537357
Filing Date: 2009-05-26
Classification: G09G

Abstract:
1. A backlight unit for a light source of a display, the backlight unit comprising: a plurality of light-emitting devices which are disposed on a substrate and driven separately; an image analyzer which analyzes an image signal and extracts position information corresponding to a region of an image requiring a relative increase or decrease of brightness; and a control unit which independently drives and controls light-emitting devices which are located in the region corresponding to the position information which is extracted by the image analyzer to increase or decrease the brightness more than that of light-emitting devices which are not located in the region corresponding to the position information; wherein each of the plurality of light-emitting devices comprises light-emitting diode (LED) chips which emit light having at least two wavelength ranges and a cone-shaped cap which covers the LED chips, wherein the LED chips are packaged on a base of the light-emitting device and are disposed at a periphery of the base, wherein the cap has a larger refractive index than a refractive index of an adjacent external medium, and the cap totally reflects at least some of the light emitted from each LED chip several times.