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Define printer and describe its types. | web4study
Define printer and describe its types.
A computer peripheral that puts text or a computer-generated image on paper or on another medium is called Printer. Printer can be categorized in several ways the most common distinction is,
1 Impact printer 2 Non-impact printer
It is the method used by the conventional typewriters. In some type of impact printer, a metal “hammer” embossed with a character strikes a print ribbon, which presses the image of the character into the paper. In other types, the hammer strikes the paper and presses it into the ribbon characters created through’! impact printing can be formed by either a solid font or dot matrix printing mechanism.
There are two groups.
1 Character printer
2 Line Printer
CHARACTER PRINTER :
Character printer prints a character at a time. These printers have only one printing head. They print 120 characters per second, an example of character printer are:
• Dot Matrix Printer
• Daisy Wheel printer
DOT MATRIX PRINTER:
Any printer that produces character made up of dots using a wire pin printed head. The quality of output from a dot matrix printer depends largely on the number of dots in the matrix, which might be low enough to show individual dots or might be high enough to approach tl19 look of fully formed characters.’ Dot matrix printers are often categorized by the number of pins in the printer head typically, 9 or 24.
DAISY WHEEL PRINTER:
Daisy wheel printer is sometimes called letter quality printer because they are often used to produce attractive correspondence. The D.W.P is a flat circular device made of metal with character embossed on it. As this wheel spins at a very high speed the hammer hits the specific character against .the ribbon which presses against the paper.
LINE PRINTERS :
Any printer that prints one line at one time, as opposed to one character at a time or one page at a time. ·Line printers typically produce .the 11 by 17-inch “computer” printout. They are high-speed devices and are often used with mainframes, minicomputers, or networked machines rather than with single user system
NON – IMPACT PRINTING:
These printers do not depend on the impact of metal on paper. In fact, no physical contact at all occurs between the printing mechanism and the paper. The most popular nonimpact methods today utilize thermal transfer, ink-jet.
An electrophotographic printer that is. based on the technology used by photocopiers. A focused laser beam and.a rotating mirror are used to draw an image of the desired page on a photosensitive drum. This image is converted on the drum into an electrostatic charge, which attracts and holds toner.
A piece of electrostatically charged paper is rolled against the drum, which pulls the toner away from the drum and onto the paper. Heat is then applied to fuse the toner to the paper. Finally, the electrified charge is removed from the drum and the excess toner is collected. By omitting the final step and repeating only the toner application and paper handling steps, the printer can make multiple copies.
THERMAL TRANSFER PRINTER:
In electrothermal printing, characters are burned on to a special paper by heated rods on a print heat. They transfer ink from a wax-based ribbon onto plai_n·paper. These printers can support high-quality graphic.
It is a kind of non-impact. Spray small dots of electrically charged ink onto a paper to form images. The ink-jet printer is flexible enough to be used as plotters.