| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, in an original lighting system using LEDs, since output of each of light sources is small, a plurality of LEDs have to be arrayed, further, if a light source is made closer to an original surface in order to increase original surface illuminance, illuminance non-uniformity considerable in a main scan direction may occur and when a light guide board being long in the main scan direction and being thick a little in a sub scan direction is used, even when the light source is separated from the original surface, scattering of light in the sub scan direction can be suppressed but illuminance drop in a terminal part of the original surface in the main scan direction may not be avoided. SOLUTION: A length Wg of a light guide member 2 is made longer than an original surface length Wp, so that reflection light from both side faces of the light guide member 2 in a length direction effectively reaches an original surface. The length Wg of the light guide member is further made longer than a length Wl of a light source unit. A difference between the lengths is set to 1/2 of an LED array interval P for each one side, as principle. COPYRIGHT: (C)2011,JPO&INPIT
|
