THE DIRECT LIGHTING BACK LIGHT FOR HIGH BRIGHTNESS

摘要

PURPOSE: A direct backlight with improved luminance is provided to form a diffusion plate thicker at an upper end part of a fluorescent lamp and thinner at both sides of the lamp, thereby minimizing the luminance at the upper end of the lamp for obtaining the uniformity in the luminance. CONSTITUTION: A direct backlight with improved luminance includes a reflection plate(20), a light guide panel(30), a diffusion plate(40), and diffusion sheets(50,52). The reflection plate has an upper part in a predetermined inclined structure(24) for inducing light from a fluorescent lamp to side surfaces. The light guide panel is provided on the reflection plate and has a lower part in a predetermined inclined structure for inducing the light from the fluorescent lamp to side surfaces. The light guide panel has an upper part formed with grooves(38) by a uniform interval for securing the fluorescent lamp and protruded curve parts(36) at both ends of the grooves. The diffusion plate is positioned on the light guide panel and mounted with the diffusion sheets which improve the uniformity in the luminance. The diffusion plate employs protrusion part(42) to be positioned on the securing grooves and depressed curve parts(44) corresponding to the protruded curve parts of the light guide panel.