Abstract: Apparatus for scanning a light-beam across a sheet mounted on a flat bed, the apparatus including a bridge that extends across the bed from one side to the other and is supported at each end on carriage guided along a respective one of said sides of the bed, a scanning head that is su ported on the bridge, drive devices at each end of the bridge to drive a respective carriage, location devices at each end of the bridge to monitor the position of each carriage along a respective one of said sides, and control device to control operation of each drive devices in accordance with information of the position of the respective carriage driven by the drive devices, determined by the respective location devices, so that both ends of the bridge are moved simultaneously in timed relation to one another.

Abstract: An apparatus and method for controlling an image recording device. The apparatus includes an acousto-optic deflector that deflects a beam of light so as to write a sub-scan comprising a predetermined number of picture elements. The image recording device is arranged to write a plurality of sub-scans side by side in a substantially contiguous manner. The apparatus also includes a component that commences sub-scans, a start of sub-scan detector that detects when the light beam is directed towards a start of sub-scan position, and an end of sub-scan detector that detects when the beam of light is directed towards an end of sub-scan position. A timing logic controller generates a start reference signal representing a desired position for the start of a sub-scan. A controller compares an output of the start of sub-scan detector with respect to the start reference signal.

Abstract: A rotary drum scanner comprises a rotatably mounted hub, a drum detachably mounted to the hub and an interlock mechanism which locks the hub against rotation until the drum is locked to the hub.