US Patent 7387421 Surface light source and backlight unit having the same

A backlight unit for a liquid crystal display is provided. The backlight unit includes a surface light source, a diffuser sheet uniformly diffusing incident light from the surface light source, and a light collection sheet collecting light diffused by the diffuser sheet. The surface light source includes a first LED arrangement in which two green LEDs, a red Led, and a blue LED are arranged in this order and a second LED arrangement in which two green LEDs, a blue LED, and a red LED are arranged in this order. The first and second LED arrangements are done along rows or columns, and, in a combination of the first and second LED arrangement, the two green LEDs are surrounded by the red and/or blue LEDs.