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  Dithering unit for multi-segment printheadUSPTO Application #: 20080111845Title: Dithering unit for multi-segment printhead Abstract: A dithering unit for a multi-segment printhead having a plurality of printhead segments that are positioned in a printhead to span a print area so that portions of consecutive printhead segments overlap in common print areas, with each printhead segment defining a lead-in area in one common print area and a lead-out area in a consecutive common print area, the dithering unit being configured to communicate with an interface to receive image data from the interface and a memory device to receive data relating to the characteristics of the multi-segment printhead, the dithering unit being configured to generate a set of dither matrices for each printhead segment so that each set has at least a lead-in dither matrix associated with the lead-in area and a lead-out dither matrix associated with the lead-out area, to generate lead-in/lead-out dither matrices for each common print area based on characteristics of the printhead segments of each common print area, to generate a variable probability value that is dependent on a scalar value that corresponds to a position along a line spanning each common print area and to interpolate the lead-in/lead-out dither matrices with the variable probability value to generate interpolated lead-in/lead-out dither matrices. (end of abstract) Agent: Silverbrook Research Pty Ltd - Balmain, AU Inventors: Kia Silverbrook, Paul Lapstun, Simon Robert Walmsley USPTO Applicaton #: 20080111845 - Class: 347015000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20080111845. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This is a Continuation of U.S. Ser. No. 10/189,459 filed on Jul. 8, 2002 FIELD OF THE INVENTION [0002] The invention relates to a print engine/controller (PEC) suitable for use with a range of printer products. The invention further relates to a print engine/controller implemented in a print head interface chip. BACKGROUND OF THE INVENTION [0003] A range of printer types have evolved wherein an image is constructed from ink selectively applied to a page in dot format. In U.S. Pat. No. 6,045,710 titled `Self-aligned construction and manufacturing process for monolithic print heads` to the inventor Kia Silverbrook there is set out an assessment of the prior art to drop on demand printers along with its manufacturing process. [0004] A microelectomechanical drop on demand print head hereafter referred to as a Memjet print head has been described in co-pending United States Patent Applications filed simultaneously to the present application and hereby incorporated by cross reference: TABLE-US-00001 USSN Our Title 09/575,152 Fluidic seal for an ink jet nozzle assembly 09/575,141 Ink jet print head having a moving nozzle with an externally arranged actuator 09/575,125 Method of manufacture of an ink jet print head having a moving nozzle with an externally arranged actuator 09/575,176 Ink jet print head nozzle array 09/575,147 Nozzle guard for an ink jet print head [0005] The Memjet print head is developed from print head segments that are capable of producing, for example, 1600 dpi bi-level dots of liquid ink across the full width of a page. Dots are easily produced in isolation, allowing dispersed-dot dithering to be exploited to its fullest. Color planes might be printed in perfect registration, allowing ideal dot-on-dot printing. The print head enables high-speed printing using microelectromechanical ink drop technology. [0006] Various methods, systems and apparatus relating to a printed page based communications network that is best worked with high-speed page printing has been disclosed in co-pending United States Patent Applications filed simultaneously by the applicant or assignee of the present invention and are hereby incorporated by cross reference: TABLE-US-00002 09/575,197, 09/575,195, 09/575,159, 09/575,132, 09/575,123, 09/575,148, 09/575,130, 09/575,165, 09/575,153, 09/575,118, 09/575,131, 09/575,116, 09/575,144, 09/575,139 09/575,186, 6,681,045, 6,728,000, 09/575,145, 09/575,192, 09/575,181, 09/575,193, 09/575,156, 09/575,183, 09/575,160, 09/575,150, 09/575,169, 6,644,642, 6,502,614, 6,622,999 6,669,385, 6,549,935, 09/575,187, 6,727,996, 6,591,884, 6,439,706, 09/575,196, 09/575,198, 6,290,349, 6,428,155, 09/575,146, 09/575,174, 09/575,163, 6,737,591, 09/575,154, 09/575,129, 09/575,124, 09/575,188 09/575,189, 09/575,162, 09/575,172, 09/575,170, 09/575,171, 09/575,161, 6,428,133, 6,526,658, 6,315,399, 6,338,548, 6,540,319, 6,328,431, 6,328,425, 09/575,127, 6,383,833, 6,464,332, 6,390,591, 09/575,152, 6,328,417, 6,409,323, 6,281,912, 6,604,810, 6,318,920, 6,488,422, 09/575,108, 09/575,109, 09/575,110 [0007] The disclosures of these co-pending applications are incorporated herein by cross-reference. [0008] Performance of a print head such as the above is dictated by its engine/controller. High-speed printing is a matter of development of both the print head and its engine/controller. A page wide print head enabled by the above technology needs an engine/controller capable of feeding it high rates of drop control signals. A typical page layout may contain a mixture of images, graphics and text. Because of the page-width nature of the above microelectromechanical print head, each page can be printed at a constant speed to avoid creating visible artifacts. This means that the printing speed need not be varied to match the input data rate. Document rasterization and document printing can be decoupled. To ensure the print head has a constant supply of data, a page should not be printed until it is fully rasterized. Ideally rasterization should be able to run ahead of the printer when rasterizing simple pages, buying time to rasterize more complex pages. The engine/controller determines the degree to which these functions might be realised. More speed at the print head depends on development of both print head and its engine/controller. The print engine/controller architecture needs to be designed to push large volumes of data to the print head at high speed. SUMMARY OF THE INVENTION [0009] In one form the invention resides in a print engine/controller comprising: [0010] a contone image decoder; [0011] a bi-level compression decoder; and [0012] a half-toner/compositor and print head interface. [0013] The print engine/controller provides the final steps for producing a page from compressed page data appropriately formatted for it by a computer or print distribution system, the steps being: expanding the page image, dithering the contone layer, compositing the black layer over the contone layer, adding infrared tags to the infrared layer, and sending the resultant image to the print head. [0014] The print engine/controller preferably uses a high speed serial interface at which to receive compressed page data. Contone image planes are decoded by a JPEG decoder and they are scaled in the halftoner/compositor under control of a margin unit. A Group 4 facsimile decoder decodes the bi-level image plane and it also is scaled in the halftoner/compositor under control of the margin unit. Optionally an infrared tag encoder serves to produce an infrared image plane to place infrared ink printed tags into a printed page. The halftoner/compositor includes a dither matrix access unit to supply dither data from the compressed page data by which to dither the contone image plane. [0015] The invention further includes a print engine/controller chip to interface with an ink drop print head comprising an interface at which to receive compressed page data, a contone image decoder to decode any continuous tone image planes in the received compressed page data, a bi-level decoder to decode any bi-level image planes and dither data in the received compressed page data, a half-toner/compositor to composite any bi-level image plane over any continuous tone image plane, and a print head driver to output the composite to a print head. BRIEF DESCRIPTION OF THE DRAWINGS [0016] FIG. 1 is a diagram illustrating data flow and the functions performed by the print engine controller. [0017] FIG. 2 shows the print engine controller in the context of the overall printer system architecture. [0018] FIG. 3 illustrates the print engine controller architecture. [0019] FIG. 4 illustrates the external interfaces to the halftoner/compositor unit (HCU) of FIG. 3. [0020] FIG. 5 is a diagram showing internal circuitry to the HCU of FIG. 4. [0021] FIG. 6 shows a block diagram illustrating the process within the dot merger unit of FIG. 5. [0022] FIG. 7 shows a diagram illustrating the process within the dot reorganization unit of FIG. 5. [0023] FIG. 8 shows a diagram illustrating the process within the line loader/format unit (LLFU) of FIG. 5. Continue reading... Full patent description for Dithering unit for multi-segment printhead Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Dithering unit for multi-segment printhead patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Dithering unit for multi-segment printhead or other areas of interest. ### Previous Patent Application: Pagewidth printhead assembly cartridge with micro-capillary feed Next Patent Application: Method of generating halftone print data for consecutive printhead segments including overlapping end portions Industry Class: Incremental printing of symbolic information ### FreshPatents.com Support Thank you for viewing the Dithering unit for multi-segment printhead patent info. IP-related news and info Results in 4.48544 seconds Other interesting Feshpatents.com categories: Canon USA , Celera Genomics , Cephalon, Inc. , Cingular Wireless , Clorox , Colgate-Palmolive , Corning , Cymer , |
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