Abstract: A queue based technique for handling proof requests in a direct digital color proofing (DDCP) system in a manner which substantially increases the throughput of proof images provided by the system while reducing needed operator interaction with the system. Specifically, proof requests are constructed to contain only parameter values that are necessary for the DDCP system to generate each proof and filename(s) of the accompanying image data therefor, but not the image data itself. These requests are queued in a proof request queue within a raster image processor (RIP) in the DDCP system and sequentially processed thereby on generally a first-in first-out basis. By restricting the requests to parameter values and an accompanying filename(s), a substantial number of these requests can be queued and sequentially processed by the RIP and printed by a proofing engine in the DDCP system without substantial operator intervention.

Abstract: A thermal printer is capable of printing proofs of images on a receiver with any of a plurality of selected half-tone dot patterns. The proof image is generated with a series of incremental dots. A plurality of the incremental dots are generated substantially simultaneously as a swath. The image is formed as a composite of a plurality of the swaths. The printer has the capability of printing with various swath widths. The swath width for a particular image is selected to preclude visible beating of the incremental dots against the selected half-tone dot pattern. Any image artifacts which are a product of interaction of the selected half-tone dot pattern and image elements (such as picket fences) are properly illustrated on the proof image. Image artifacts that are the product of interactions of the incremental dots and the half-tone dots are made invisible to the human eye.

Abstract: There is disclosed a method for providing precise color-to-color registration of color dots in a multicolor proof with a thermal printer comprising a CPU and Printer Controller, a Motion Controller, a writing drum, and a writing head coupled to a translation means. Using the disclosed method, a proof and a dye donor member with a predetermined dye color thereon are mounted on the writing drum. The writing head is then moved to a predetermined start position defined by a sensor at a predetermined position along the translation means which has its optical path blocked by the writing head. The writing head is then moved forward to a predetermined home position which is defined by a next subsequent pulse from a multi-pulse radial position-indicating encoder coupled to the translation means occurring after the writing head leaves the start position.

Abstract: A sheet removal apparatus for unloading a sheet from a hollow drum mounted for rotation about its axis and having a vacuum provided to the interior thereof and to first and second sets of vacuum openings through the surface of the drum. The sheet is arranged to overlie and close the first set of vacuum openings with the second set of openings extending substantially parallel with an edge of the sheet and comprising only a small portion of the total number of vacuum openings through the drum. An exit blade is disposed adjacent the drum and has an edge proximate the drum that extends substantially parallel to the edge of the sheet and forms an acute angle with the drum surface with the proximate edge of the blade closely adjacent the apex of the angle and parallel with the edge of the sheet. When the drum is rotated to a sheet removal position, the first set of vacuum openings lies beneath the acute angle when the edge of the sheet is disposed on the opposite side of the apex.