Abstract: The printing apparatus according to the present invention includes a system for pre-warning of impending shutdown due to slippage of sheets within the printing apparatus sheet transport system. The system includes a plurality of sensors positioned along a sheet transport path for sensing sheets moving along the sheet transport path and a controller for determining an amount and location of slip within the sheet transport path by comparing outputs of the plurality of sensors. Once the location of the slip has been determined, automatic correction may be performed by the printing apparatus or manual correction may be performed by a service representative.

Abstract: An imaging system for forming multiple superimposed image exposure frames on a photoconductive member moving in a process direction including a rotating polygon having a plurality of facets. A raster output scanner forms a plurality of scanlines in a transverse direction across the photoconductive member by reflecting modulated beams from the rotating polygon. A control provides a start of scan (SOS) signal for each of the facets of the rotating polygon, determines the facet related to the first scanline of a first image exposure frame on the photoconductive member, and initiates the first scanline of each succeeding superimposed image exposure frame on the photoconductive member in relation to the facet related to the first scanline of the first image exposure frame.

Abstract: A gun cleaner has an elongated sleeve, a rod reciprocally mounted in the sleeve, a gun cleaning element attached to the rod, and mounting means attached to the sleeve for slidably guiding the rod along a major axis of the sleeve between a retracted position with the gun cleaning element at least substantially disposed within the sleeve and an extended position with the head and a portion of the rod extending outwardly from the end of the sleeve.

Abstract: In a facsimile communication system transmitting a signal sequence indicative of a scan-by-scan reading of a document, the improvement including a scan interlock control system for matching the scan pitch rate in the receiver with the scan pitch rate in the transmitter. During each scan, the transmitter provides a scan synchronization pulse which is compared for coincidence with a receiver scan synchronization pulse. If a mismatch is found, the minimum bit width in a receiver scan counter is altered by a variable length counter towards a matching direction. The adjusted scan counter then provides the serial bits of data which, through a D/A converter, control the scanning mechanism in the receiver.