Print engine with pipeline decoding
View Patent ↗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 image decoders to perform an expansion, in pipeline fashion, for the received compressed page data. A half-toner/compositer ( 29 ) composites respective strips of the decoded image planes and sends output to a printhead interface ( 32 ). A printhead interface ( 32 ) interfaces with the printhead. A synchronization signal generator ( 89,90 ) may output a synchronization signal that is used to synchronize print engine/controllers. One printhead interface ( 32 ) preferably 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. The half-toner/compositor ( 29 ) scales input image planes under control of a margin unit ( 57 ) set the print engine/controller to establish print data for a strip only of the image, the image being built from the respective strips from the multiple print engine/controllers.
1. A print engine/controller configurable to be coupled with others to drive a multi-segment printhead comprising:
a memory buffer for receiving compressed page data;
image decoders to perform an expansion, in pipeline fashion, of the compressed page data;
a half-toner/compositer to composite respective strips of the decoded image planes; 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 pipeline fashion expansion further comprises the expansion, in parallel, of a JPEG-compressed contone CMYK layer and at least one other layer.
3. The print engine/controller of claim 2 wherein:
the other layer is a Group 4 Fax-compressed bi-level black layer.
4. The print engine/controller of claim 3 wherein:
the pipeline fashion expansion further comprises the expansion, in parallel with the layers, of a Group 4 Fax-compressed bi-level dither matrix selection map.
5. The print engine/controller of claim 2 further comprising:
a tag encoder for encoding bi-level infra-red tag data from the compressed page data.
6. The print engine/controller of claim 4 wherein:
the pipeline fashion expansion further comprises a second stage dithering of the contone CMYK layer using a dither matrix selected by the dither matrix select map.
7. The print engine/controller of claim 6 wherein:
the second stage further comprises a compositing of the bi-level black layer over a resulting bi-level K layer.
8. The print engine/controller of claim 7 further comprising:
the second stage further comprises the generation of an infra-red layer.
9. The print engine/controller of claim 7 further comprising:
the second stage further comprises the generation of a fixative layer.
10. The print engine/controller of claim 9 wherein:
the fixative layer is generated at each dot position according to the need in a C, M, Y, K or IR channel.
11. The print engine/controller of claim 1 wherein:
the pipeline fashion expansion is performed using a high speed serial interface, a standard JPEG decoder 28 , a standard Group 4 Fax decoder, a half-toner/compositor unit, a tag encoder, a line loader/formatter unit.
12. The print engine/controller of claim 11 wherein:
the decoders and encoder are buffered to the half-toner/compositor.
13. The print engine/controller of claim 12 wherein:
the high speed serial interface is an IEEE 1394 interface.
14. The print engine/controller of claim 1 wherein:
the printhead interface includes an input at which a signal determines if the print engine controller is a master controller or a slave.
15. The print engine/controller of claim 1 wherein;
the half-toner/compositor scales input image planes under control of a margin unit set to establish print data for a strip of the image.