Print engine/controller with half-toner/compositor

• US 6,992,791 B2
• Filed: 11/17/2003
• Issued: 01/31/2006
• Est. Priority Date: 06/30/2000
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Lapstun, Paul, Walmsley, Simon Robert
• Primary Examiner(s): Tran, Douglas Q.
• Application Number:
  US10/713,083
• Publication Number:
  US 20040095608A1
• Time in Patent Office: 806 Days
• Field of Search: 358 11- 118
• US Class Current: 358/1.18
• CPC Class Codes: G06F 3/1208 resulting in improved quality of the output result, e.g. print layout, colours, workflows, print preview
• CPC Class Codes: G06F 3/1213 at an intermediate node or at the final node
• CPC Class Codes: G06F 3/1277 using filter pipeline, e.g. outside the driver, adding traps
• CPC Class Codes: G06F 3/1282 High volume printer device

Abstract

A print engine/controller (10) configured to be coupled with others to drive an ink drop printhead (33). It has an interface (27) at which to receive compressed page data. Image decoders (28, 88) decode compressed image planes in the received compressed page data. A half-toner/compositer (29) a half-toner/compositer composites respective strips of the decoded image planes by halftoning a contone layer to a bi-level version and compositing a spot1 bi-level layer over an appropriate halftoned contone layer. A printhead interface (32) interfaces with the printhead. A synchronization signal generator (89,90) outputs a synchronization signal that is used to synchronize print engine/controllers. In some embodiments, one printhead interface (32) acts as master generating the synchronization signal to synchronize all the print engine/controllers to drive the printhead at any one or more of higher speed, higher input resolution, higher outlet resolution or wider format.

Claims

1. A print engine/controller configured to be coupled with other similar print engine/controllers to drive an ink drop printhead comprising:

an interface at which to receive compressed page data;

image decoders to decode compressed image planes in the received compressed page data;

a half-toner/compositer to composite respective strips of the decoded image planes by halftoning a contone layer to a bi-level version and compositing a spot1 bi-level layer over an appropriate halftoned contone layer; and

a printhead interface to output the composite strip to a printhead the printhead interface including;

a multi-segment printhead interface outputting printhead formatted data; and

a synchronization signal generator outputting a synchronization signal to couple print engine/controllers to synchronize their respective strips at the printhead.

2. The print engine/controller of claim 1, wherein:

the half-toner/compositer is adapted to map K to CMY dots when there is no K ink in a printer.

3. The print engine/controller of claim 1, wherein:

the half-toner/compositer selects between two dither matrices on a pixel by pixel basis based on a corresponding value in a dither matrix select map.

4. The print engine/controller of claim 1, wherein:

the half-toner/compositer has as an input, an expanded contone layer, an expanded bi-level spot1 layer, an expanded dither-matrix-select bitmap and tag data.

5. The print engine/controller of claim 4, wherein:

the tag data is at full dot resolution.

6. The print engine/controller of claim 1, wherein:

the half-toner/compositer selects between two dither matrices on a pixel by pixel basis based on a corresponding value in a dither matrix select map.

7. The print engine/controller of claim 1, wherein:

the half-toner/compositor includes a margin unit to apply margin data to the respective image planes during the composite process to generate print data in strips.

8. The print engine/controller of claim 1, wherein:

the halftoner/compositor scales input image planes under control of a margin unit set to establish print data for a strip of the image.

9. The print engine/controller of claim 1, wherein:

the half-toner/compositor further comprises a number of scale units, each scale unit receiving data from a buffer layer and at least one scale unit receiving two control bits, the control bits being an advance dot bit and an advance line bit.

10. The print engine/controller of claim 9, wherein:

the advance dot bit allows for the generation of multiple instances of identical dot data and the advance line bit provides for truncation of data according to a printer margin.

11. The print engine/controller of claim 9, wherein:

the buffer layers comprise contone layers, a bi-level spot1 layer and a dither select matrix layer, each of which may be scaled independently.

12. The print engine/controller of claim 11, further comprising:

a bi-level tag data buffer which does not require scaling.

13. The print engine/controller of claim 9, further comprising:

a compositing stage for a number of output layers, the compositing stage having for an output layer, a single dot merger unit with inputs equal in number to the number of output layers.

14. The print engine/controller of claim 13, further comprising:

a dot reorg unit which takes a generated dot stream for a given color plane and organizes it into fixed length quantities so that an output of the half-toner/compositor is in segment order and not in dot order within segments.

15. The print engine/controller of claim 13, wherein:

the dot reorg unit is adapted to receive a dot advance signal from a dither matrix access unit as an instruction as to which bit to output.

16. The print engine/controller of claim 10, further comprising:

a margin unit for turning the advance dot and advance line signals into general control signals based on a page margin of a current page.

17. The print engine/controller of claim 16, wherein:

the margin unit also generates an end of page condition and keeps a counter for dot and line across a page.

18. The print engine/controller of claim 17, wherein:

the dot counter is advanceable by 1 each time the margin unit receives a dot advance signal and re-settable to zero when the margin unit receives a line advance signal.

19. The print engine/controller of claim 1, further comprising:

a line loader/format unit for receiving dot information from the half-toner/compositor and loading dots for a given print line into an appropriate buffer storage, formatting them into an order required by a printhead.