Understanding Printers

Although there are many different kinds of printers, there are two main categories: ink- or bubble-jet, and laser. An ink-jet printer works by spraying ionized ink on a sheet of paper. Ink-jet printers are less expensive and considerably slower than laser printers, but they still produce a good quality output. A laser printer utilizes a laser beam to produce an image on a drum, which is rolled through a reservoir of toner and transferred to the paper through a combination of heat and pressure. Laser printers are faster and produce a higher quality output than ink- jets , but are they also more expensive. Ink-jet and laser printers are combined with other hardware devices, such as copier and scanner, into a multi-function device. A multi-function device provides common device functionality at a lower cost than purchasing each device separately. Printers are classified by two main characteristics: resolution and speed. Printer resolution refers to the sharpness and clarity of a printed page. For printers, the resolution indicates the number of dots per inch (dpi). For example, a 300-dpi printer is one that is capable of printing 300 distinct dots in a line one-inch long, or 90,000 dots per square inch. The higher the dpi, the sharper the print quality. Printer speed is measured in pages per minute (ppm). The speed of printers varies widely. In general, ink-jet printers range from about 4 to 10 ppm, while laser printers range from about 10 to 30 ppm. The speed depends on the page's contents: if there is just text or the page has only one color , the ppm is in the high range, but when a page contains graphics and/or has multiple colors, the ppm rate falls to the low range.


Show Me Microsoft Windows XP
Show Me Microsoft Windows XP (2nd Edition)
ISBN: 0789733366
EAN: 2147483647
Year: 2002
Pages: 391

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