| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problems in various kinds of original illuminating devices proposed for almost uniformly illuminating a face to be illuminated long in the main scanning direction by a plurality of light-emitting elements arranged in a line in its direction, in which a long cylinder lens is provided between the face to be illuminated and the light-emitting elements and a light flux emitted to the fronts of the light-emitting elements and passing through the lens becomes almost a parallel light flux, while, a high illuminance part remains at the end of the main scanning direction (it is presumed that the light flux converges around there). <P>SOLUTION: The light beam emitted from the light-emitting element 1 reaches the rear face 3a (the face to be illuminated) of a contact glass 3 via a cylinder lens 2. The light flux emitted in the sub-scanning cross section becomes divergent light on the face to be illuminated as shown by a solid line. The light flux emitted in the direction having an angle to the sub-scanning cross section becomes the same state as the state that a light path length is substantially extended as shown by a broken line. The light flux becomes parallel light at a prescribed skew angle θp. Consequently, the high-illuminance part is not formed at the end part of the main scanning direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
