A scanner comprises a transparent platen mounted on a housing, and an object-imaging device within the housing mounted for longitudinal movement relative to the platen and an object supported thereby. The object-imaging device is rotatable about a transverse axis and comprises an aperture for receiving light reflected from the object. The object-imaging device has a travel distance between a home end position and a back end position, the travel distance comprising a central portion and at least one end portion. The scanner further comprises a mechanism operatively associated with the object-imaging device for rotating the device about the transverse axis thereof in response to movement of the device within the at least one end portion of the travel distance, the device being rotated in a direction so that the light-receiving aperture is rotated away from the central portion of the travel distance.