| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize an image reading device capable of reducing an image surface curvature and a magnification deviation in a secondary scanning direction even when using a high-resolution line sensor. <P>SOLUTION: The image reading device includes: an image reading lens for imaging image information of a document; and reading means disposed in the imaging position of the image information and having a plurality of line sensors in which pixels are arranged in a primary scanning direction. The image reader reads image information by moving the reading means in a secondary scanning direction. The reading means satisfies W/L≥0.015 (where W is the width of each line sensor on the shorter side, and L is the interval between the centers of adjoining line sensors). The image reading lens has an anamorphic lens including an anamorphic face in which at least one face is rotationally asymmetric with respect to an optical axis. Where the cross-sectional form of the anamorphic face within a main scanning cross-section including the optical axis and the main scanning direction is a generatrix, at least one face of the anamorphic lens is such that a sagittal curvature continuously changes in the direction of the generatrix from the optical axis and satisfies a conditional expression. Here, the sagittal curvature is defined within a plane that is perpendicular to the main scanning cross-section and includes a normal line at an arbitrary position in the generatrix direction. <P>COPYRIGHT: (C)2012,JPO&INPIT |
