| 摘要 |
Light guide design for an edge-type backlight unit in a display device. The upper surface of the guide (120) is divided by a step into two regions: Reg. I (130) and Reg. II (140); moreover, the guide exhibits a recess or indented channel at its edge opposite to the light sources (112). In each region the guide has a different thickness, with the upper surface in Reg. II being set back from Reg. I by the step. Optical sheets (160) are disposed on the guide surface in Reg. II abutting the step and may be held in place by tabs 142 on the guide surface. The recess at the edge of the guide in Reg. I may accommodate the light sources. The design saves space, reduces light leakage and enhances the reliability of light emission in the backlight. Optionally, reflective films may be arranged in the recess and/or on the lower surface of the guide in Reg. II. A light-scattering pattern may also be arranged on the upper surface in Reg. I. The lower surface of the guide may be inclined in Reg. II, so that the guide has a wedge shape. Indications for preferable sizes, size ratios and shapes (e.g. curvature) for both the recess and the step are given. |
