Patent attributes
In an image reading device which includes a transmission light source and a pickup device which face each other with original platen glass for holding an original interposed therebetween, receives light irradiated from the transmission light source by the pickup device, and reads a light transmission original, a pickup device movement mechanism which reciprocally moves the pickup device in a predetermined direction is interlockingly connected to a light source movement mechanism which reciprocally moves the transmission light source in the predetermined direction in interlock with the reciprocal movement of the pickup device movement mechanism by a connection mechanism. The connection mechanism has a torque limiter function for generating sliding between the light source movement mechanism and the pickup device movement mechanism when torque equal to or greater than a predetermined value is delivered.