US Patent 7732828 Flat panel display

A flat panel display is provided. The flat panel display includes a display panel. A light guide plate is disposed below the display panel. At least one optical film is disposed between the display panel and the light guide plate. At least one illuminating device package is disposed in proximity to the side of the light guide plate. The illuminating device package includes an illuminating semiconductor device and a lens encapsulating the illuminating semiconductor device. The lens includes two reflective surfaces disposed at either side of a central axis. A plurality of diffractive surfaces are disposed between the reflective surfaces. Each of the diffractive surfaces has a tilt angle respective to the central axis. A first portion of light beams incident to each of the reflective surfaces is reflected to at least one diffractive surface and then diffracted and collected into a first convergent angle.