Dithered image for bi-level printing

• US 7,177,052 B2
• Filed: 12/27/2004
• Issued: 02/13/2007
• Est. Priority Date: 11/09/1998
• Status: Expired due to Fees

• Current Assignee: Zamtec Limited (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul, Walmsley, Simon Robert
• Primary Examiner(s): Grant, II; Jerome
• Application Number:
  US11/021,090
• Publication Number:
  US 20050105138A1
• Time in Patent Office: 778 Days
• Field of Search: 358/1.9, 358/2.1, 358/3.13, 358/3.16, 358/2.99, 358/3.1
• US Class Current: 358/3.13
• CPC Class Codes: B41J 11/008 Controlling printhead for accurately positioning print image on printing material, e.g. with the intention to control the width of margins
• CPC Class Codes: B41J 11/42 Controlling printing material conveyance for accurate alignment of the printing material with the printhead; Print registering
• CPC Class Codes: B41J 13/103 for the sheet feeding section
• CPC Class Codes: B41J 2/0452 reducing demand in current or voltage
• CPC Class Codes: B41J 2/04528 aiming at warming up the head
• CPC Class Codes: B41J 2/04543 Block driving
• CPC Class Codes: B41J 2/04551 using several operating modes
• CPC Class Codes: B41J 2/04563 detecting head temperature; Ink temperature
• CPC Class Codes: B41J 2/0457 Power supply level being detected or varied
• CPC Class Codes: B41J 2/0458 controlling heads based on heating elements forming bubbles
• CPC Class Codes: B41J 2/04586 controlling heads of a type not covered by groups B41J2/04575 - B41J2/04585, or of an undefined type
• CPC Class Codes: B41J 2/04591 Width of the driving signal being adjusted
• CPC Class Codes: B41J 2/04596 Non-ejecting pulses
• CPC Class Codes: B41J 2/155 for line printing
• CPC Class Codes: B41J 2/16505 Caps, spittoons or covers for cleaning or preventing drying out
• CPC Class Codes: B41J 2/16511 Constructions for cap positioning B41J2/16547 takes precedence
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/175 Ink supply systems ; Circuit parts therefor
• CPC Class Codes: B41J 2/17566 Ink level or ink residue control
• CPC Class Codes: B41J 2/515 line printer type
• CPC Class Codes: B41J 2002/17569 : based on the amount printed or to be printed
• CPC Class Codes: B41J 2202/17 : Readable information on the head
• CPC Class Codes: B41J 2202/20 : Modules
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B41J 25/34 : Bodily-changeable print heads or carriages
• CPC Class Codes: B41J 29/02 : Framework
• CPC Class Codes: B41J 29/13 : Cases or covers
• CPC Class Codes: B41J 29/38 : Drives, motors, controls or automatic cut-off devices for the entire printing mechanism
• CPC Class Codes: G03G 15/0863 : provided with identifying means or means for storing process- or use parameters, e.g. an electronic memory
• CPC Class Codes: G03G 15/55 : Self-diagnostics; Malfunction or lifetime display
• CPC Class Codes: G03G 2215/0697 : being an electronically readable memory
• CPC Class Codes: G03G 2221/1823 : Cartridges having electronically readable memory
• CPC Class Codes: G06F 3/1213 : at an intermediate node or at the final node
• CPC Class Codes: G06F 3/1214 : at the submitting node
• CPC Class Codes: G06F 3/122 : with regard to computing resources, e.g. memory, CPU
• CPC Class Codes: G06F 3/1247 : by conversion to printer ready format
• CPC Class Codes: G06F 3/1284 : Local printer device
• CPC Class Codes: G06K 15/00 : Arrangements for producing a permanent visual presentation of the output data , e.g. computer output printersprinting or plotting combined with another operation, e.g. with conveying, G06K17/00
• CPC Class Codes: G06K 15/02 : using printers
• CPC Class Codes: G06K 15/102 : using ink jet print heads
• CPC Class Codes: G06K 15/1814 : including print-ready data, i.e. data already matched to the printing process
• CPC Class Codes: G06K 15/1815 : Receiving print data in mixed format
• CPC Class Codes: G06K 15/1817 : Buffers
• CPC Class Codes: G06K 15/1852 : involving combining data of different types
• CPC Class Codes: G06K 15/1855 : Combining raster data and graphic primitives
• CPC Class Codes: G06K 15/1856 : characterized by its workflow
• CPC Class Codes: G06K 15/1857 : involving parallel processing in the same printing apparatus
• CPC Class Codes: G06K 2215/0094 : Colour printing
• CPC Class Codes: H04N 1/32561 : using a programmed control device, e.g. a microprocessor
• CPC Class Codes: H04N 1/32587 : Controller
• CPC Class Codes: H04N 1/32598 : Bus based systems
• CPC Class Codes: H04N 1/3871 : the composed originals being of different kinds, e.g. low- and high-resolution originals
• CPC Class Codes: H04N 1/40 : Picture signal circuits H04N1/387 takes precedence
• CPC Class Codes: H04N 1/41 : Bandwidth or redundancy reduction by scanning H04N1/17 ; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/60 : Colour correction or control H04N1/54 takes precedence
• CPC Class Codes: H04N 1/642 : Adapting to different types of images, e.g. characters, graphs, black and white image portions

Abstract

A method of printing a contone image in the form an array of contone color pixel values using a printer adapted to print bi-level dots. In the method comprising the contone image is dithered using a dithering volume, the dithering comprising assigning for each dither cell location a fixed set of n thresholds defining n+1 intensity intervals within which the dither cell location is defined to an alternative not set and set.

Claims

1. A method of printing a contone image in the form of an array of contone color pixel values using a printer adapted to print bi-level dots, the method comprising dithering said contone image using a dithering volume, said dithering comprising assigning for each dither cell location a fixed set of n thresholds defining n+1 intensity intervals within which said dither cell location is alternatively not set and set;

said method further comprising printing said dithered image.

2. A method of printing according to claim 1, including the steps of dividing each dither cells into subcells, and storing each address of the subcells in separately addressable memories from which said n thresholds are retrieved in parallel.