| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading apparatus capable of discriminating whether dirt is stuck on an optical member outside a casing or on an optical member inside the casing. SOLUTION: A shading plate 59 within a casing 41 is read, and whether dirt is stuck or not is detected based on a level of an image signal obtained in a CCD 32. Furthermore, a backup plate 58 is read via contact glass 47 outside the casing 41 and whether dirt is stuck or not is detected based on a level of an image signal obtained in the CCD 32. If dirt is detected when the shading plate 59 is read, it is discriminated that dirt is stuck on an optical member (light source 31, mirror 55, 56, 57, image forming lens 54, CCD 32) inside the casing 41 and if dirt is detected when the back plate 58 is read, it is determined that dirt is stuck on an optical member (contact glass 47) outside the casing 41. It is then notified to the user by displaying a message urging the user to perform cleaning. COPYRIGHT: (C)2007,JPO&INPIT
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