A document backing extending in a plane is resiliently biased in a direction substantially parallel to the plane.

A driving device of the present invention includes a drive wire and a drive pulley. The drive pulley has a fixing hole and a guide groove on a wire-winding surface thereof on which the drive wire is wound. The drive wire is disposed in the guide groove and fixed in a fixing hole by a fixing member. A bottom face of the guide groove has a curved face portion formed in a boundary region of the wire-winding surface and the guide groove.

An image reading device of the present invention includes a reading unit in which a lighting system and an optical system are mounted, a controller provided at a position where the controller does not transfer along with the reading unit, and a flexible flat cable that includes a curved portion and connects the reading unit with the controller. The lighting system includes an elongated light conductor extended in the main scanning direction and an end portion light source arranged at the end portion of the light conductor. The flexible flat cable is arranged on the outside of the optical system and on the lower side of the light conductor.

A driving device is used in an image reading apparatus, and reciprocates a scanning unit for reading an image on an original. The driving device comprises a pull member, a driving pulley which transmits driving force to the pull member, a following pulley which applies tension to the pull member and a pulley holder having a pulley axis which holds the following pulley rotatably. Then, the pulley axis has a lock pawl capable of locking an upper end portion of the following pulley and canceling engagement with the following pulley by being tilted toward a side of an axial center by elastic deformation. Furthermore, the lock pawl is arranged at a side of a tension acting direction from the pull member to the following pulley except the farthest position from the driving pulley among positions in a circumferential direction of the pulley axis. It is possible to attach and detach the following pulley easily at a time of maintenance or the like.

An image reading apparatus includes a reader that reads an image of a document by using plural light receiving elements arranged in a first scanning direction; a moving unit that moves the reader in a second scanning direction to move a reading position at which the reader reads the document; and an adjusting unit that moves the reader in the first scanning direction to adjust a position of the reader in the first scanning direction.

A driving device is used in an image reading apparatus, and reciprocates a scanning unit for reading an image on an original. The driving device comprises a pull member, a driving pulley which transmits driving force to the pull member, a following pulley which applies tension to the pull member and a pulley holder having a pulley axis which holds the following pulley rotatably. Then, the pulley axis has a lock pawl capable of locking an upper end portion of the following pulley and canceling engagement with the following pulley by being tilted toward a side of an axial center by elastic deformation. Furthermore, the lock pawl is arranged at a side of a tension acting direction from the pull member to the following pulley except the farthest position from the driving pulley among positions in a circumferential direction of the pulley axis. It is possible to attach and detach the following pulley easily at a time of maintenance or the like.

An image forming apparatus includes a main apparatus for forming an image on a sheet and an image reading apparatus for reading an image on an original. The main apparatus includes a discharge tray on which the sheet, on which the image is formed, is stacked. The image reading apparatus includes a housing to accommodate a reading unit, a sensor disposed on a bottom surface of the housing and a cable connected to the sensor. A lower surface of the bottom surface is positioned above a discharge tray and forms an upper portion of a discharge space to which the sheet, on which the image is formed, is discharged. In a bottom surface of the housing, a groove which is recessed downward inside the housing and protrudes in the discharge space is formed. The cable is arranged to pass through inside the groove.