Patent ID: 7746522

Claim:
An image reading device comprising: a transparent board having a surface on which a document is placed; a carriage provided on the side of the back surface of the transparent board so as to be movable parallel with the transparent board; a linear image sensor mounted on the carriage in the direction perpendicular to the moving direction to perform an image reading operation for the document placed on the transparent board; a plurality of positioning members provided on the image sensor in the vicinity of both ends of the image sensor in a longitudinal direction and on a part of the image sensor not in the vicinity of the ends, the plurality of positioning members projected so as to abut on the transparent board; and a forcing member provided in the carriage to force the image sensor toward the transparent board, wherein the positioning member arranged on the part of the image sensor not in the vicinity of the ends is arranged outside the reading region of a document having a predetermined size on the transparent board.