| 摘要 |
A backlight device is provided to be usable as a backlight or a surface-type illumination light source of an LCD display, and to solve non-uniform brightness, thereby realizing a low cost and lightness of the backlight device. A backlight device(1) comprises as follows. A case(30) has an opening unit(32) and a bottom unit(34). A light source(40) is installed within the case. An optical face part(20) is installed in the opening unit of the case. Plural supporting members support the optical face part on a side of the bottom unit of the case. Given that a radius of a circle centering around the supporting members is 'r(mm)' and thickness of the optical face part is 'T(mm)', a range of the opening unit of the case is included and configured by a circle of the radius 'r' that satisfies a conditional expression T<=0.7 or r<=175T+27.5. |
