| 摘要 |
It is necessary that paper be moved past the printhead at a constant velocity to obtain artifact-free printing. Therefore the printhead requires a constant stream of data during printing. Whilst it is possible to rasterize the page using a page description language directly to the printhead, it is uneconomical. Hence the redering is carried out in the PC. However, the standard USB peripheral connection is the standard connection on PCs, which places a constraint on the limit of data per page that can be transmitted to the printer and still obtain a reasonable rate of printing. Thus the contone images and graphics are rendered in the PC to a pixel level, and the black text and graphics are rendered in the PC to a dot level, where the rendered data is compressed and transmitted to the printer. The transmitted data is decompressed and combined and the images overlaid and printed.
|
