Pagewidth inkjet printer having composite image printing control

• US 7,173,739 B2
• Filed: 05/06/2005
• Issued: 02/06/2007
• Est. Priority Date: 05/23/2000
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia, Lapstun, Paul, Walmsley, Simon Robert
• Primary Examiner(s): Rogers; Scott A.
• Application Number:
  US11/123,011
• Publication Number:
  US 20050200864A1
• Time in Patent Office: 641 Days
• Field of Search: 358 19- 301, 358/1.2, 358/3.06, 358/3.24, 358/462, 358/502, 358/534, 358/539, 358/450, 347/15, 382/233
• US Class Current: 358/2.1
• CPC Class Codes: B41J 2/2132 Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding methods for local corrections by dot omission, image edge enhancement, or multi-pass mask selection G06K15/102; colour conversion H04N1/40
• CPC Class Codes: H04N 1/3871 the composed originals being of different kinds, e.g. low- and high-resolution originals
• CPC Class Codes: H04N 1/405 Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels
• CPC Class Codes: H04N 1/4051 producing a dispersed dots halftone pattern, the dots having substantially the same size different sizes H04N1/4057

Abstract

A printer is provided comprising a pagewidth inkjet printhead for printing bi-level dots of ink onto print media at a resolution of 800 to 1600 dpi and a controller for controlling the pagewidth inkjet printhead. The controller comprises a receiver for receiving compressed page data to be printed by the printhead, a first decoder configured to decode any compressed continuous tone image planes in the received compressed page data at a resolution of up to 320 ppi in each plane, a second decoder configured to decode any compressed bi-level image planes in the received compressed page data at a resolution of 320 to 1600 dpi in each plane, a half-toner/compositor for creating a composite image by halftoning the decoded continuous tone image planes and compositing the decoded bi-level image planes over the halftoned continuous tone image planes, and a printhead driver arranged to output the composite image to the printhead.

Claims

1. A printer comprising:

a pagewidth inkjet printhead for printing bi-level dots of ink onto print media at a resolution of 800 to 1600 dpi; and

at least one controller for controlling the pagewidth inkjet printhead, the, or each, controller comprising;

a receiver for receiving compressed page data to be printed by the printhead;

a first decoder configured to decode any compressed continuous tone image planes in the received compressed page data at a resolution of up to 320 ppi in each plane;

a second decoder configured to decode any compressed bi-level image planes in the received compressed page data at a resolution of 320 to 1600 dpi in each plane;

a half-toner/compositor for creating a composite image by halftoning the continuous tone image planes decoded by the first decoder and compositing the bi-level image planes decoded by the second decoder over the halftoned continuous tone image planes; and

a printhead driver arranged to output the composite image to the printhead.

2. A printer as claimed in claim 1, wherein the first decoder is a JPEG decoder.

3. A printer as claimed in claim 1, wherein the first decoder outputs separate color planes of the decoded continuous tone image planes to separate buffers of the half-toner/compositor.

4. A printer as claimed in claim 1, wherein page data in each continuous tone image plane is scaled in the half-toner/compositor.

5. A printer as claimed in claim 1, wherein the second decoder is a Group 4 facsimile decoder.

6. A printer as claimed in claim 1, wherein the second decoder outputs the decoded bi-level image planes to respective buffers of the half-toner/compositor.

7. A printer as claimed in claim 1, wherein page data in each bi-level image plane is scaled in the half-toner/compositor.

8. A printer as claimed in claim 1, wherein the at least one controller further comprises an infrared tag encoder arranged to produce an infrared image plane to place infrared ink printed tags into a printed page.

9. A printer as claimed in claim 1, wherein the half-toner/compositor incorporates a dot merger unit controlled by a color mask to effect integration of the image planes with what inks are provided in the printhead.

10. A printer as claimed in claim 1, wherein the half-toner/compositor incorporates a margin unit arranged to apply margin data to the respective image planes during the compositing.