Friday, June 24, 2011

How Dot Matrix Printers work

Dot Matrix printers also called impact printers print the characters by striking the combinations of pins on the print ribbon; the ribbon in turn strikes the paper which is placed against the drum and at the point of the impact characters gets printed on the paper.

Dot matrix printers were extensively used during 1970’s and 1980’s, though these printers created lot of noise and were slow to print but they were extremely popular on account of less cost price per print page. Gradually dot matrix printers were replaced in most places by inkjet printers which were more efficient than the former due to less noise, fast printing and more importantly better print quality. But still the dot matrix printers are brought to use at many places where the more pages are needed to print and quality is not much of a consideration e.g. like cash registers or in places like banks or offices where large amount of data logs are to printed.

Since the characters are printed when the pins strike the ribbon, the number of pins can be said to be directly proportional to the print quality. Earlier dot matrix printers used to have nine pins but the print quality wasn’t that great, then the companies started manufacturing printers with 18 or 24 print heads. 24 head printer used to print quickly and better quality and graphics. Some of these printers even had magnet print heads which were faster and with better quality. The speed of dot matrix printers can vary from 50 to 500 cps.

Though some companies like Apple Inc. introduced colored dot matrix printers but they never really gained wide spread acceptance because of poor print quality. In colored dot matrix printers there are three or more ribbons of different colors and when we type anything the combination is printed by aligning these ribbons and generating the desired pattern. But the colored ribbons sometimes used to overlap black colored ribbons and one would get distorted pictures or characters.

Dot matrix printers like any other impact printer can be used to print carbon copies. These printers are less common today and as mentioned have been more or less replaced by inkjet and laser printers. The latter kinds of printers especially give better print quality and at a much faster rate.

No comments:

Post a Comment