This invention concerns a printhead capping mechanism for preventing evaporation of ink from a printhead when it is not in use. The invention has utility, for instance, in a color printer which uses a drop-on-demand inkjet printhead. The mechanism includes a cap fitted with an elastomeric seal to seal against the face of the printhead, and a sponge to catch drops ejected from the printhead during the nozzle cleaning cycle. The mechanism also includes an actuating structure operable to selectively move the cap between an engaged position to press against the printhead and a disengaged position spaced away from the printhead.
1. A method of transferring generate pages from a processing system to a printer for printing, each generated page comprising at least graphics and text, the method comprising:
a) For each generated page causing the processing system to:
i) Render contone data representative of the graphics;
ii) Render bi-level data representative of the text;
iii) Compress the contone and bi-level data to form page data; and,
iv) Transfer the page data to the printer;
b) Causing the printer to:
i) Receive the page data;
ii) Decompress the contone and bi-level data;
iii) Generate composite bi-level data from the contone data and the bi-level data; and,
iv) Print each page in accordance with the generated composite bi-level data.
2. A method according to claim 1 , the method comprising causing the printer to:
a) Generate halftone contone data from the decompressed contone data; and,
b) Generate the composite bi-level data from the halftone contone data and the bi-level data.
3. A method according to claim 2 , the contone data being in an RGB format, the method comprising causing the printer to generate RGB halftone contone data.
4. A method according to claim 3 , the method comprising causing the printer to convert the composite bi-level data to CMYK data for printing.
5. A method according to claim 1 , the method comprising compositing the bi-level data and the halftone data in accordance with any one of the claims 1 to 4 .
6. A method according to claim 1 , the method comprising causing the processing system to:
a) Identify any obscured text, the text being obscured by one or more graphics; and,
b) Generate the contone data and the bi-level data in accordance with the obscured text.
7. A method according to claim 1 , the method comprising compressing the contone data using a JPEG type compression algorithm.
8. A method according to claim 7 , the method comprising causing the processing system to compress the contone data as separate luminance and chrominance channels.
9. A method according to claim 8 , wherein if the contone data includes CMYK contone data, the method comprises causing the processing system to:
a) Convert the CMY data into YcrCb data;
b) Sub-sample the Cr and Cb data to form the chrominance channel;
c) Form a luminance channel from at least the K data.
10. A method according to claim 1 , the method comprising compressing the bi-level data using at least one of:
a) Group 3 facsimile Compression;
b) Group 4 facsimile Compression; and,
c) Bi-level Edge Delta and Runlength (EDRL) Compression.
11. A method according to claim 1 , the method comprising:
a) Causing the processing system to render a page n and generate an associated page data; and,
b) Causing the processing system to simultaneously;
i) Render a page n+1 and generate the associated page data; and
ii) Transfer the page data for the page n to the printer;
c) Simultaneously;
i) Causing the processing system to:
(1) Render a page n+2 and generate the associated page data; and
(2) Transfer the page data for the page n+1 to the printer; and,
ii) Causing the printer to print the page n; and,
d) Repeating step (c) for subsequent pages as required.
12. A method according to claim 11 , the processing system comprising at least two stores, the method comprising:
a) Rendering the contone and bi-level data for a page;
b) Storing the contone and bi-level data in respective stores; and,
c) Compressing the contone and bi-level data stored in the stores to form the page data.
13. A method according to claim 12 , the printer comprising a page store, a contone store, a bi-level store and a composite bi-level store, the method comprising causing the printer to:
a) Store the received page data in the page store;
b) Decompress the page data stored in the page store;
c) Store the contone data and the bi-level data in the contone and bi-level stores respectively;
d) Generate the halftone data from the contone data stored in the contone store;
e) Generate the composite bi-level data from the halftone data and the bi-level data stored in the bi-level store; and,
f) Store the composite bi-level data in the composite bi-level store.
14. A method according to claim 1 , the compressed contone and bi-level data having a size of below 3 Mb.
15. A printer adapted to receive a generated page from a processing system, the page comprising graphics and text, the printer comprising a processor adapted to:
a) Receive page data, page data comprising compressed contone data representative of the graphics and compressed bi-level data representative of the text;
b) Decompress the contone and bi-level data;
c) Generate composite bi-level data from the contone data and the bi-level data; and,
d) Print each page in accordance with the generated composite bi-level data.
16. A printer according to claim 15 , the processor being adapted to:
a) Generate halftone contone data from the decompressed contone data; and,
b) Generate the composite bi-level data from the halftone contone data and the bi-level data.
17. A printer according to claim 16 , the contone data being in an RGB format, the processor being adapted to generate RGB halftone contone data.
18. A printer according to claim 17 , the processor being adapted to convert the composite bi-level data to CMYK data for printing.
19. A printer according to claim 15 , the processor being adapted to composite the bi-level data and the halftone data in accordance with any one of the claims 15 to 18 .
20. A printer according to claim 15 , the contone data being compressed using a JPEG type compression algorithm.
21. A printer according to claim 15 , the bi-level data being compressed using at least one of:
a) Group 3 facsimile Compression;
b) Group 4 facsimile Compression; and,
c) Bi-level Edge Delta and Runlength (EDRL) Compression.
22. A printer according to claim 15 , the printer comprising a page store, a contone store, a bi-level store and a composite bi-level store, the processor being adapted to:
a) Store the received page data in the page store;
b) Decompress the page data stored in the page store;
c) Store the contone data and the bi-level data in the contone and bi-level stores respectively;
d) Generate the halftone data from the contone data stored in the contone store;
e) Generate the composite bi-level data from the halftone data and the bi-level data stored in the bi-level store; and,
f) Store the composite bi-level data in the composite bi-level store.
23. A processing system adapted to transfer a generated page to a printer for subsequent printing, the page comprising graphics and text, the processing system comprising a processor adapted to:
a) Render contone data representative of the graphics;
b) Render bi-level data representative of the text;
c) Compress the contone and bi-level data to form page data; and,
d) Transfer the page data to the printer, the printer being responsive to the page data to:
i) Decompress the contone and bi-level data;
ii) Generate composite bi-level data from the contone data and the bi-level data; and,
iii) Print each page in accordance with the generated composite bi-level data.
24. A processing system according to claim 23 , the processor being adapted to generate contone data in an RGB format.
25. A processing system according to claim 24 , the processor being adapted to:
a) Identify any obscured text, the text being obscured by one or more graphics; and,
b) Generate the contone data and the bi-level data in accordance with the obscured text.
26. A processing system according to claim 23 , the processor being adapted to compress the contone data using a JPEG type compression algorithm.
27. A processing system according to claim 23 , the processor being adapted to compress the contone data as separate luminance and chrominance channels.
28. A processing system according to claim 27 , wherein if the contone data includes CMYK contone data, the processor being adapted:
a) Convert the CMY data into YcrCb data;
b) Sub-sample the Cr and Cb data to form the chrominance channel;
c) Form a luminance channel from at least the K data.
29. A processing system according to claim 23 , the processor being adapted to compress the bi-level data using at least one of:
a) Group 3 facsimile Compression;
b) Group 4 facsimile Compression; and,
c) Bi-level Edge Delta and Runlength (EDRL) Compression.
30. A processing system according to claim 23 , the processor being adapted to:
a) Render a page n and generate an associated page data; and,
b) Simultaneously;
i) Render a page n+1 and generate the associated page data; and
ii) Transfer the page data for the page n to the printer; and,
c) Repeating step (b) for subsequent pages as required.
31. A processing system according to claim 23 , the processing system comprising at least two stores, the processor being adapted to:
a) Render the contone and bi-level data for a page;
b) Store the contone and bi-level data in respective stores; and
c) Compress the contone and bi-level data stored in the stores to form the page data.
32. A processing system according to claim 23 , the processor being adapted to generate compressed contone and bi-level data having a size of below 3 Mb.