 a page printer is a computer printer which processes and prints a whole page at a time, as opposed to printers which print one line or character at a time such as line printers and dot-matrix printers. page printers are often all incorrectly termed âlaser printersâ&mdash;although virtually all laser printers are page printers, other page printing technologies also exist. ==components== the components of a page printer are: *a print engine, "the unit within a printer that does the actual printing." for example, in a laser printer this would consist of the laser and drum and the mechanical paper feeds. * memory to process input and build up the image of a page. the printer may have its own memory or may use the host computerâs memory. * a page description language (pdl), with commands which tell the printer how to format the page. popular pdls are pcl (printer command language) from hewlett-packard, postscript from adobe systems and postscript clones, and windowsâ graphics device interface (gdi). *a raster image processor (rip), i.e. a processor which constructs the bitmap image of the page. sometimes, this processing is done by the host computer. in other cases printers may have powerful processors to perform this task. *a printer driver, a program (device driver) which converts the computerâs information about the page into the actual pdl. printer drivers may be included with the operating system, be distributed with the printer on cds or dvds, or be downloaded from the printer manufacturerâs home page or from independent web sites. *a connection (interface) to the host computer. many printers communicate by wi-fi. other popular interfaces are usb and ethernet. many older printers also have a parallel (centronix) interface. high-end printers often have a channel interface for direct connection to a mainframe computer. ==page printing technologies== there are several page printing technologies, for example: *laser printers, in which a laser beam draws the page image on charged drum which collects charged toner and transfers the image to paper. *led printers, which use light-emitting diodes instead of a laser beam, but are otherwise very similar to laser printers. *melted wax (âphaserâ) printers, where solid ink is heated to the melting point and is applied on the print medium where it immediately solidifies. *dye-sublimation printers, where a solid ink (dye) is converted to a gaseous state (sublimation) and applied on the print m
Printing