Lens unit , LED heads , an exposure apparatus , an image forming apparatus and a reader

摘要

PROBLEM TO BE SOLVED: To suppress a relative displacement and a shape difference between components due to contraction and expansion of materials and prevent reduction in resolution.;SOLUTION: A lens unit 1 comprises: a first lens array 10 in which a plurality of first lens elements 12 are arranged in a row in an arrangement direction approximately perpendicular to a first optical axis; a second lens array 10 in which a plurality of second lens elements 12 are arranged in a row in an arrangement direction approximately perpendicular to a second optical axis; and a shading member 20 having a plurality of diaphragms 22 passing the first optical axis and the second optical axis and arranged in a row in an arrangement direction. The first lens array is arranged to face the second lens array with an approximately same shape so as to coincide the first optical axis with the second optical axis, and the second lens array is arranged at a position opposite to the first lens array when rotating with a straight line 25 parallel to an arrangement direction as a rotation axis.;COPYRIGHT: (C)2013,JPO&INPIT