Patent ID: 7922368
Filing Date: 2011-04-12
Classification: G02B,G02F

Abstract:
1. A backlight unit comprising: a second substrate including at least one light cube, the light cube having: red, green, and blue light emitting diodes disposed on a first substrate; a first lens disposed on the first substrate to cover the red, green, and blue light emitting diodes; a second lens having a concave portion that receives the first lens and forming a space between the first lens and the second lens; a diffusion sheet disposed on a reflective sheet; a light concentrating sheet disposed on the diffusion sheet, wherein the first lens is formed of a silicon material and has a hemispheric shape that is disposed on the red, green and blue light emitting diodes, wherein the concave portion has a slant surface and a space with a curved surface including a large amount of curvature, a medium curvature, and a small curvature on the top, middle and bottom, respectively, wherein the space between the first lens and second lens operates as a third lens to make more refraction at the surface of the first lens and the concave surface of the second lens, wherein the concave portion of the second lens includes an inner surface having a pentagon shaped surface in cross section along a light emitting axis of the light cube wherein the pentagon shaped surface has one of five sides open to receive the first lens and the first substrate.