摘要 |
An image reading device (3) incorporatable in an image forming apparatus (1) includes a housing (53) including a first housing member (51) having a document reading area and a second housing member (52) attached to the first housing member, a document reading unit (21) disposed inside the housing (53) to read a document (MS) while moving in a sub-scanning direction of the housing (53), a document reference line (51a) formed on the first housing member (51) to position the document (MS) placed on the document reading area in the sub-scanning direction, and a reference position detector (56) positioned on a plane surface of a square that extends perpendicular to the document reading area along a main scanning direction of the document reference line (51a) to detect a reference position of the document reading unit (21) as the document reading unit (21) moves in the sub-scanning direction. |