| 摘要 |
PROBLEM TO BE SOLVED: To provide an image reading device capable of stably conveying a document without narrowing a gap of a conveyance path, even when a document contacts a white reference roller to cause the white reference roller slightly rotate during conveyance of the document, and when a direction of the white reference roller is deviated from a target position to a certain degree due to an error in position control, so as to contribute to improvement of accuracy of read images, and consequently improvement of image quality in image formation.SOLUTION: A white reference roller 26 has a shape of combining circular arc parts 26b and 26c having lengths of diameters from a rotation center 26a different from each other. A sign 62 represents a document reading surface. During shading data acquisition, the reading surface and the white reference roller 26 are substantially in contact with each other. During document conveyance, the circular arc part 26c having a radius of r2 is directed to the document reading surface so as to secure a conveyance gap t necessary for conveyance of the document. |
