Drop firing control in multicolor ink jet printheads

• US 6,921,144 B2
• Filed: 07/08/2002
• Issued: 07/26/2005
• 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): Nguyen, Lamson D.
• Application Number:
  US10/189,459
• Publication Number:
  US 20030076373A1
• Time in Patent Office: 1,114 Days
• Field of Search: 347/15, 358/1.2, 358/1.9, 358/2.99, 358/3.01, 358/3.06, 358/3.13, 358/534, 382/166, 382/233
• US Class Current: 347/15
• 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 print engine/controller suited to use with a drop on demand print head. The print engine/controller works with compressed page data having both JPEG contone image layers and a bi-level image plane compressed using a Group 4 facsimile protocol. It receives compressed image plane'"'"'s and effects expansion and printing in a pipeline fashion. It consists of a high speed serial interface 27 (such as a standard IEEE 1394 interface), a standard JPEG decoder 28, a standard Group 4 Fax decoder, a halftoner/compositor unit 29, a tag encoder 30 by which to place infrared tags into a printed page, a line loader/formatter unit 31 feeding an interface 32 to the print head 33. The decoders 28,88 and encoder 30 are buffered to the halftoner/compositor 29.

Claims

1. A printer comprising:

an inkjet printhead;

a print engine/controller comprising;

(i) a memory buffer configured to receive compressed page data supplied to the printer;

(ii) a contone image decoder to decode any compressed continuous tone image planes in the received compressed page data;

(iii) a bi-level decoder to decode any compressed bi-level image planes in the received compressed page data;

(iv) a half-toner/compositor to dither any continuous tone image planes and composite bi-level image plane data with any output plane; and

(v) a printhead driver to output the composite to the printhead;

wherein the print engine/controller is configured to enable a current page to be read from the memory buffer whilst a following page is being stored in the buffer.

2. A print engine/controller as claimed in claim 1 wherein the interface is a high-speed serial interface.

3. A print engine/controller as claimed in claim 1 wherein the contone image decoder is a JPEG decoder.

4. A print engine/controller as claimed in claim 1 wherein the contone image decoder outputs the separate color planes of the decoded image to separate buffers in a front end to the halftoner/compositor.

5. A print engine/controller as claimed in claim 1 wherein page data in each contone image plane is scaled in the halftoner/compositor.

6. A print engine/controller as claimed in claim 1 wherein the bi-level decoder is a Group 4 facsimile decoder.

7. A print engine/controller as claimed in claim 1 wherein the bi-level decoder decodes any compressed bi-level image plane in the received compressed image plane to respective buffers in a front end to the halftoner/compositor.

8. A print engine/controller as claimed in claim 1 wherein the page data in the bi-level image plane is scaled in the halftoner/compositor.

9. A print engine/controller as claimed in claim 1 further including an infrared tag encoder to produce an infrared image plane to place infrared ink printed tags into a printed page.

10. A printer comprising:

an ink drop printhead;

a print engine/controller to drive the printhead, the print engine/controller comprising;

(i) a memory buffer configured to receive compressed page data supplied to the printer;

(ii) a contone image decoder to decode any compressed continuous tone image planes in the received compressed page data;

(iii) a bi-level decoder to decode any compressed bi-level image plane in the received compressed page data; and

(iv) a halftone/compositor including a dot merger unit controlled by a color mask to effect integration of the image planes with what inks are provided in the printhead;

wherein the print engine/controller is configured to enable a current page to be read from the memory buffer whilst a following page is being stored in the buffer.

11. A printer comprising:

an ink drop printhead;

a print engine/controller to drive the printhead, the print engine/controller comprising;

(i) a memory buffer configured to receive compressed page data supplied to the printer

(ii) a contone image decoder to decode any compressed continuous tone image planes in the received compressed page data;

(iii) a bi-level decoder to decode any compressed bi-level image plane in the received compressed page data; and

(iv) a halftone/compositor including a margin unit to apply margin data to the respective image planes during the composite process;

wherein the print engine/controller is configured to enable a current page to be read from the memory buffer whilst a following page is being stored in the memory buffer.