Rotary image scanner capable of mounting drums of various diameters

Abstract

A dual drum rotary image scanner has a headstock and a tailstock between which may be mounted drums of different diameter. The tailstock has substantially annular surfaces which contact corresponding surfaces on the different diameter drums. The different drums, when held in the scanner, each create a different separation between the headstock and tailstock. These different separations are detected by photodetectors, the outputs of which are received by a system controller. The controller uses the photodetector signals to control motors that position the scanning head and the transmittance illuminator relative to the surface of the particular drum mounted in the scanner. The motors turn pinions which, in turn, move racks to which are attached the scanning head and the transmittance illuminator, respectively. The movement of the scanning head also results in the modification of the optical path within the optics box of the scanner. In a first position, the light from the scanning head follows a first optical path which includes a movable mirror in a first angular orientation. As the scanning head is moved to a second position, the angular orientation of the movable mirror is changed, and the light from the scanning head follows a second optical path which includes the movable mirror in its new orientation. Support arms are also provided which adjust to support the different diameter drums during loading, and mounting surfaces between the drum being mounted and the headstock and tailstock are shaped to allow the drum to be lifted off the supports as the headstock and tailstock are brought together.