| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical scanner whose constitution is made simple, while reducing the size and the cost and to provide an image forming device having the optical scanner. SOLUTION: In an fθlens 56 of a scanner unit 13, a first incident surface 71 of a first lens 69 is formed into a non-spherical surface, which is rotationally symmetrical around an optical axis Z referenced to the optical axis Z; a first emitting surface 72 is formed into an unsymmetrical shape along the main scanning direction Y, with respect to the optical axis Z and also formed into the shapes in which the curvature of a sub-scanning direction X is unsymmetrical with respect to the optical axis Z. Moreover, a second incident surface 76 and a second emitting surface 77 of a second lens 70 are formed into shapes, which are symmetrical along the main scanning direction Y, with respect to the optical axis Z and also formed into the shapes, in which the curvature of the sub-scanning direction X is symmetrically changed, with respect to the optical axis Z. Thus, only the first emitting surface 72 of the first lens 69 is required to be formed into the shape which varies in an unsymmetrical manner, production of the metallic mold is facilitated, and cost is reduced. COPYRIGHT: (C)2006,JPO&NCIPI
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