| 摘要 |
PURPOSE: A back light unit for an LCD is provided to increase the amount of effective incident light from a lamp to a waveguide by improving the shape of a lamp cover. CONSTITUTION: A back light unit(100) for an LCD includes at least one lamp(20), a lamp cover(10), a waveguide(30) and sheets(40). The lamp cover(10) has upper and lower plates(14,15) for covering the lamp(20) and side plates(13) bent from the ends of the upper and lower plates(14,15) to form sharp points at the outermost portions, and reflects light from the lamp(20) through the upper, lower and side plates(14,15,13). The sheets(40) are arranged in front of the waveguide(30) for outputting light through the waveguide(30) to liquid crystal panels(202). A normal line, which is perpendicular to a plane of incident of the waveguide(30) and passes the center of the lamp(20), meets the sharp points at the outermost portions of the side plates(13). |
