| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading apparatus using an image reading lens capable of reducing both of curved field aberration and magnification shift of a sub-scanning direction. SOLUTION: The image reading apparatus has a photoelectric conversion element for arranging a pixel in a main-scanning direction in a one-dimensional direction, and the image reading lens for imaging image information on an original on a light receiving face of the photoelectric conversion element. The image reading lens has at least one anamorphic lens comprising an anamorphic face by both faces of an incident face and an emission face. When a cross sectional shape of the anamorphic face in a main-scanning cross section including the optical axis of the image reading lens and the main-scanning direction is made a mother line, child line curvature defined in a face including a normal line of the anamorphic face at a position of an arbitrary mother line direction and vertical to the main-scanning cross section continuously changes as separated along a mother line direction from the optical axis and each condition expression is satisfied. COPYRIGHT: (C)2008,JPO&INPIT
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