| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a direct type backlight unit using LEDs as a light source capable of getting rid of luminance unevenness of a display screen and maintaining high luminance in order to realize low energy consumption and thinning of a liquid crystal display. <P>SOLUTION: The direct type backlight unit is provided with two or more point light sources arranged on a reflective sheet and with a light diffusion panel arranged on a light outgoing side of the point light sources. As the light diffusion panel (1), an object with a convex type structure molded on all over its surface is used on a light outgoing face on an opposite side from the point light source side, with a bottom face square and equipped with symmetrical planes perpendicular to the bottom face and parallel to each of the sides on the bottom face, and with a maximum tilt angle against the bottom face of the convex outline shape to be 25-75°. Also as an optical sheet (2) which is layered up on the light diffusion panel (1), at least one sheet of the object with the convex type structure molded on all over its surface is used; with a bottom face square and equipped with symmetrical planes perpendicular to the bottom face and parallel to each of the sides on the bottom face, with a maximum tilt angle against the bottom face of the convex outline shape to be 25-75°. <P>COPYRIGHT: (C)2011,JPO&INPIT |
