Digital printing system
View Patent ↗A digital printing system that includes a personal computer and a printer. The computer includes a printer driver that receives and compresses print data. The printer is connected to the personal computer and includes a data expansion system and a page-width color inkjet printhead. A transmission system is connected to both the personal computer and to the printer for transmitting the compressed print data from the personal computer to the data expansion system of the printer.
1. A digital printing system comprising:
a personal computer comprising a printer driver, wherein said printer driver receives print data and compresses said print data;
a printer operatively connected to said personal computer, said printer comprising a data expansion system and a page-width color drop-on-demand microelectromechanical inkjet printhead; and
a transmission system operatively connected to both said personal computer and to said printer for transmitting said compressed print data from said personal computer to said data expansion system of said printer.
2. A digital printing system according to claim 1 , wherein said printer driver manages a buffer having first and second layers, said first layer of said buffer containing background contone data and said second layer of said buffer containing foreground bi-level pixel data.
3. A digital printing system according to claim 2 , wherein said background contone data is color data and wherein said foreground bi-level data is black data.
4. A digital printing system according to claim 3 , wherein said system is operative to:
composite a black image object with said bi-level second layer of said buffer;
composite a contone color image object with said contone first layer of said buffer;
wherever a contone color image object obscures said bi-level second layer, said obscured bi-level second layer pixel data are composited with said contone first layer and removed from said bi-level second layer before a contone color image object is composited with said contone first layer.
5. A digital printing system according to claim 2 , wherein EDRL compression is used to compress said foreground bi-level pixel data.
6. A digital printing system according to claim 2 , wherein JPEG compression or wavelet compression is used to compress said background contone data.
7. A digital printing system according to claim 1 , wherein said transmission system comprises a universal serial bus (USB) connection.
8. A digital printing system according to claim 1 , wherein said compressed print data comprises data from a page and wherein said data expansion system is operative to expand said compressed print data as said page is being printed.
9. A digital printing system according to claim 1 , wherein said data expansion system is operative to decompress 267 ppi contone CMYK image data, halftone resulting contone pixels to 1600 dpi bi-level CMYK dots, decompress 800 dpi bi-level black text data, and composite resulting bi-level black text dots over the corresponding bi-level CMYK image dots.
10. A digital printing system according to claim 1 , wherein said page-width printhead is an 8″ page-width printhead.