| 摘要 |
PROBLEM TO BE SOLVED: To specify the position of a carriage on which a linear light source is mounted in a short time.SOLUTION: A rotation body 51 which can be rotated around a rotation axis parallel to a main scan direction is provided on a first original glass 13. A black rotation position detection mark 56 is provided in a predetermined position in a circumferential direction on the outer circumferential surface 51b of the rotation body 51. In a period except for reading an original image, in such a state that a linear light source 18a mounted on a carriage 18 is turned on, the rotation body 51 is rotated, it is determined whether or not the rotation position detection mark 56 is detected by an image sensor 18b mounted on the carriage 18, and the position of the carriage 18 is specified based on the rotation angle of the rotation body 51 when the rotation position detection mark 56 is detected. |
