BACK LIGHT GUIDE PLATE

PURPOSE:To make the constitution compact and obtain a bright screen, to reduce necessary electric power for driving and prolong the life of a battery, and to stabilize the brightness by forming extremely small reflecting surfaces, which reflect incident light from side surfaces to the front, integrally on the rear surface of the light guide plate. CONSTITUTION:A light guide body 4 is provided on the back of a liquid crystal panel 1 and rod type illumination lamps 2 are placed on one or both sides of the light guide body 4; and many narrow slanting surfaces which reflect the light from the illumination lamps 2 to the front are constituted on the back surface of the light guide plate 4 and the size and arrangement of the slanting surfaces are set in inverse proportion to the quantity of light from the illumination lamps 2. Further, claw shapes 10, etc., like V grooves and U shapes for positioning the illumination lamps 2 are provided at the fitting parts of the illumination lamps 2. Then a metallic film which serve as a reflecting mirror is formed by plating, vapor deposition, etc., outside the slanting surface parts. Further, a scatter plate 3 which scatters the light from the light guide plate 4 is provided between the light guide plate 4 and liquid crystal panel 1.