Xerox Corporation

Munir G Salfity

George L Eldridge

John Cheng Ming Tou

Michael E Farrell

Peter A Crean

David E Rumph

Mark A Smith

Thomas Robson

San A Phong

William Samuel Jacobs

Daniel Fleysher

Yuanta Kuo

Robert E Lyons

Eric J Thibodeau

A circuit which uses a compressor to divide each separation image into 8-line strips, and to independently compress each strip, a single decompressor to decompress two or more color image separations, strip by strip, by interleaving them, and to apply them to two or more print heads, one for each color separation. DMA from a main memory is used to apply both separations to the decompressor, and the decompressor output is demultiplexed into two print heads, one for each separation. This is done to drive each color separation simultaneously in a single-pass color printer. Multiplexing logic controls the DMA into the decompressor and the output of the decompressor into separate buffers for each color separation. Additional logic uses the page and line sync from each print head to synchronize the accessing of the correct image raster from buffers at the output of the decompressor to the associated print head.

Time multiplexed image data decompression circuit

The invention generates a page description language compliant data stream, that has been pre-designed and pre-processed to create unique and predictable page element ordering, overlay layout, and for splitting large page elements into multiple independent elements. In this way, multiple processors can be used to render the document without merging the data stream.

Systems and methods for rapid processing of raster intensive color documents

A high speed image data interface between a print server containing a page description language decomposer and an interface card, and a printer containing a rendering card and a print engine, where the interface card is physically located in the printer case and is plugged into the backplane of the printer. The interface is synchronous and carries clock, page request, line request and reset signals from the renderer, and line valid, error and data signals from the interface card. Other communications between the printer and server are carried by a telephone line or local area network. The advantage of this arrangement is that the printer manufacturer can design the printer without having to design the interface card to match the server manufacturer's requirements.

Image data interface between digital front end and printer

A system for using the page buffer memory which stores the pixel map to generate the cursor in a CRT display. An unused portion of the memory is used to store a duplicate copy of the band in which the cursor is currently located, and the cursor is written into its appropriate location in this duplicate band, thus destroying the underlying image in the duplicate, but not in the original. The display is then generated by cycling through the page buffer except that the duplicate band containing the cursor, instead of the original band containing the underlying image, is displayed. After each display is generated, during the time when the scan returns from the bottom to the top of the display, if the cursor has moved since the previous display, the new band containing the cursor is created in the unused portion, and the display process is repeated.

Method of generating a cursor

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Torrance, CA, United States of America

Munir G Salfity