Lexmark International, Inc.

Christopher Mark Songer

Martin Geoffrey Rivers

Gail Marie Songer

James Francis Webb

Michael Donald Bender

Jeffrey Keith Wedinger

Jay Scott Martin

John K Brown, Iii

Jeffrey A Minnick

John Francis Gostomski

Hugh Deral Spears

Matthew Scott Keith

Bryan Leslie Ethington

An improved printer is provided which includes a separate hardware compression module and hardware decompression module contained within the ASIC of the print engine. A 'Request Counter' register is decremented each time memory is requested to store a block of bitmap image data. When the Request Counter decreases to a predetermined value, the current size of the remaining 'free memory' space is evaluated. If this free memory is less than another predetermined value (a 'low water mark'), then blocks of data that have already been stored in the printer's memory are sent to the compression module to be compressed before the printer literally runs out of free memory, and the printer can continue storing and processing more incoming print job data. By thus preserving some of the free memory, the printer can continue to process or rasterize more print data while the compression hardware simultaneously operates independently to compress one or more blocks of data. Since the compressor hardware operate independently of the printer's microprocessor, the printer can continue to process further data during the actual compression operations, thereby preventing the printer's microprocessor from becoming idle, which otherwise would become a very inefficient utilization of the printer's processing power. The present invention is especially useful in processing color data, especially in printers containing relatively small quantities of RAM, since color data typically requires four (4) planes of bitmap image data per page to be printed.

Method and apparatus for compressing and decompressing print data in the

An improved networked system having a host computer and multiple printers is provided in which the printers have a bi-directional data communications capability and have at least one memory device capable of storing print data and other types of data files. The host computer can be utilized by a user or a Network Administrator to 'read' the contents of each memory device on each printer connected to the network that has the NPAP bi-directional communications capability. The user/Network Administrator can de-fragment data files (e.g., print job files) on a flash RAM memory device, or can format one of the memory devices of a printer (which deletes all of the files stored on that memory device). Furthermore, the user/Network Administrator can transfer a file from the memory of one of the printers on the network to the memory of a second of the printers on the network. When a given resource management function has been completed, an updated resource directory is automatically displayed at the host which includes all of the changes resulting from the earlier resource management function command. Once the printer receives an NPAP command of the type that accesses the resource management capabilities of the printer, the printer's Emulation Manager will control the execution of the resource management function that has been received. The Emulation Manager communicates the command along with the required arguments to the Common File System, which performs the actual data manipulation of any of the files in the memory devices.

Method and apparatus for providing remote printer resource management

An improved printer is provided that improves the response time before jobs are printer by providing a 'fast data path' for certain print jobs while also storing on a hard disk all incoming print job data. This 'fast data path' is especially useful in situations where the incoming print job lacks an 'end of file' code, which could otherwise hold up the processing of either this print job or later print jobs. Once the printer becomes relatively busy, and begins to accumulate a 'queue' of print jobs waiting to be processed and printed, the printer will automatically store all of the print job data on the non-volatile memory (e.g., a hard disk) before that same data is sent to the processing circuitry. Since it is important to utilize the printer's capabilities efficiently, the printer can allow a 'small' print job to be processed and printed after being received from one input port of the printer, while a much larger print job is still being accumulated from a second input port, even though the larger job began to be received first. Since all print job data received by the printer of the present invention is stored in a non-volatile memory, the capability exists for recovering such print jobs after the occurrence of a power failure. Upon power restoration, a 'Header File' that contains status information about stored print jobs will be inspected, and if a print job was never completely printed, the printer will now begin printing the entire job. In this manner, the printer can guarantee that the entire job will be printed in one intact grouping of sheets of paper.

Method and apparatus for providing print job buffering for a printer on

Printer (1) has code in memory (5) to interpret one or more page description languages and also stores in memory (5) a table of routines useful in other interpreters and their addresses, as well as code to link partially compiled object code in response to directions in Relocation Tables in the partially compiled code. Data is downloaded to the printer by cable (23) to add another interpreter to the printer. That data is employed by the linking code, which responds to the directions in the Relocation Tables to complete the new interpreter making use of routines already stored in the printer. Since the stored routine table is lengthy, it is compressed. The routine table may be downloaded rather than permanently stored.

Download of interpreter to a printer

An improved networked system having a host computer and multiple printers is provided in which the printers have a bi-directional data communications capability and have at least one memory device capable of storing print data and other types of data files. The host computer can be utilized by a user or a Network Administrator to 'read' the contents of each memory device on each printer connected to the network that has the NPAP bi-directional communications capability. The user/Network Administrator can transfer a file from the memory of one of the printers on the network to the memory of a second of the printers on the network. When a given resource management function has been completed, an updated resource directory is automatically displayed at the host which includes all of the changes resulting from the earlier resource management function command. Once the printer receives an NPAP command of the type that accesses the resource management capabilities of the printer, the printer's Emulation Manager will control the execution of the resource management function that has been received. The Emulation Manager communicates the command along with the required arguments to the Common File System, which performs the actual data manipulation of any of the files in the memory devices.

To process bit maps for full color and other data-intense bit maps for printing, a data processing routine (FIG. 4) determines if a block at data within a page is not in color or is otherwise in a single value. Such data is stored in DRAM (28) in one bit per pel form. Other blocks are stored with eight bit for each pel. A table is then developed defining the contiguous order in a page (FIG. 6). An ASIC (32) then transfers the pel information in order of printing to a video RAM (40) with the eight bits restored for data stored in one bit per pel form. The data applied to that ASIC is decompressed.

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Lexington, KY, United States of America

Christopher Mark Songer