What is printer? What is the classification of computer printer? Mention the parameters to choice a best printer.
|Subject||Introduction to Computer System|
|NU Year||Set: 2.(d) Marks: 6 Year: 2009|
A printer is a device that accepts text and graphic output from a computer and transfers the information to paper, usually to standard size sheets of paper. Printers vary in size, speed, sophistication, and cost. In general, more expensive printers are used for higher-resolution color printing.
Classification of Printer
Printer classification based on their technology.
Typical printer types are:
1. Dot matrix printer
2. Ink-jet printer
3. Laser printer
Dot Matrix Printer
A dot matrix printer or impact matrix printer refers to a type of computer printer with a print head that runs back and forth on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like a typewriter.
Dot-matrix technology uses a series or matrix of pins to create printed dots arranged to form characters on a piece of paper. Because the printing involves mechanical pressure, these printers can create carbon copies and carbonless copies.
The print head mechanism pushes each pin into the ribbon, which then strikes the paper.
Many offices and government agencies use them because they can make multiple copies at lowest cost. Although dot matrix printers have been replaced in most homes and offices by newer, sexier inkjet and laser printers , they still retain a substantial portion of the market in their niches.
Ink Jet Printers
An inkjet printer is a type of computer printer that creates a digital image by propelling droplets of ink onto paper. Inkjet printers are the most commonly used type of printer and range from small inexpensive consumer models to very large professional machines that can cost up to thousands of dollars. Its consumable called inkjet cartridge.
Laser printing is the most advance technology. In Laser printing, a computer sends data to the printer. Printer translates this data into printable image data. This kind of printers uses xerographic principle. A laser beam discharges photo sensitive drum. A Latent Image is created on drum, during development process toner is attracted to the drum surface and then transferred to the paper. Its consumable called toner cartridge or laser toner.