Pagewidth inkjet printer having composite image printing control
View Patent ↗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.
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.