An output device is an electromagneticdevice which accepts data from a computerand translates them into a form, which issuitable for use by the outside world.
TYPES OF OUTPUT1. SOFT COPY OUTPUT— It is not produced on a paper or some other material which can be touched. They are temporary in nature and vanish after use.2. HARD COPY OUTPUT— It is produced on a paper or some other material which can be touched. They are permanent in nature and used any time.
Printers are the most common used output devicestoday for producing hard copy output .
DOT MATRIX PRINTER It is a character printer which prints one character at a time in the pattern of dots. It has a printer head with array of pins which works independently to strike against an inked ribbon to form a pattern of dots on the paper. They can print any shape of character, graphics, different sizes of print, which a programmer can describe. They are impact printers and hence noisy. They can be used to produce multiple copies by using carbon paper. Speed is slow, 30 to 600 characters per second. Used in printing shipping forms, invoices etc..
INKJET PRINTER It is a character printer which form characters and all kinds of images by spraying small drops of ink onto the paper. They produce high output quality. Its print resolution is 360 dots per inch. They can print any shape of characters, different sizes of print, print graphics etc. They are non impact printers as they print by spraying ink on the paper and hence not noisy. They cannot produce multiple copies. They are slower than dot matrix printer ranging between 40 to 300 characters per second. Used where speed is not an important factor.
WORKINGThe print head containsupto 64 tiny nozzles,which can be selectivelyheated in a few microseconds by an integratedcircuit register. By this ,the ink vaporizes and isejected and makes a doton the paper placed infront of the print head.
DRUM PRINTER These are line printers which print one line at a time. It consists of a solid cylindrical drum, hammers, inked ribbon. Total no. of hammers is equal to the total no. of bands on the drum. The drum rotates at a very high speed. All characters are not printed at a same time but due to its high speed it appears as if one line is printed at a time. It is expensive hence cannot be changed frequently. No ability to print any shape of characters, different sizes of print, and graphics. Impact printer. Hence can be used to produce multiple copies at a time. Noisy in operation. Speed is 300 to 2000 lines per minute.
WORKINGThe drum rotates at ahigh speed, and acharacter at a printposition is printed byactivating theappropriate hammer ,when the characterembossed on the band atthe print position passesbelow it. Hence, thedrum would have tocomplete one fullrevolution to print eachline of output.
CHAIN/BAND PRINTER These are line printers which print one line at a time. It consists of a chain band, set of hammers, inked ribbon. The chain can easily be changed which allows the use of different fonts, scripts etc. No ability to print any shape, size of characters. Impact printers hence noisy in operation. Can be used to produce multiple copies at a time. Speed is 400 to 3000 lines per minute.
Its working is same as that of drum printers but here with thisprinter the advantage is that the character set is repeatedseveral times on a chain, it is not necessary to wait for the chainto make a complete revolution to position the desired characterin the correct print position.
LASER PRINTER These are page printers which print one page at a time. Its main components are a laser beam source, a multi sided mirror, a photoconductive drum and toner (tiny particles of oppositely charged ink). It produces very high quality output because they form characters by very tiny ink particles. They can print any shape, size of characters. Non impact printers. Hence non noisy and can produce multiple copies at a time. COMMON PRINTERS- resolution 600 dpi and can print 4 to 12 pages per minute. HIGH END LASER PRINTER- resolution 1200 dpi and can print 500 to 1000 pages per minute i.e. one whole book.
To print a page the laser beam is focused on the electro staticallycharged drum by the spinning multisided mirror which thenfocuses the beam on the drum in a manner to create the patternsof characters on the page. As the drum is photo conductivepotential difference creates on the exposed part of drum surfacewhich attracts the toner composed of oppositely charged inkparticles and permanently fuses it to generate the printed output.The toner is then removed by a rubber blade.
LATEST PRINTERS LED/ LCD PRINTER DIGITAL PHOTO PRINTER It is a electro photographic These are able to print photo printer which is somewhat quality images. identical to laser printer. Photo print heads allow a Both liquid crystal display greater resolution to improve and light emitting diode use a photo image quality. light source instead of a laser PHOTO INK JET PRINTERS beam to produce an output. expand gamuts by adding Rest is identical to laser additional ink colors, usually printer. light cyan and light magenta.
.... MULTIFUNCTIONNETWORK PRINTER PRINTER It provides output capabilities It combines top quality color to all network users. By it you laser printing, color copying, can save both space and color scanning and money when you share over a telephoning. network. WIRELESS PRINTER LABEL PRINTER It allows to work with It prints labels one at a time wireless network, i.e. print which are of high quality. It anywhere in office. can print different labels , e.g. Bar codes, different size of labels on goods.
OTHER SUCH LATEST PRINTERS1. CD/DVD PRINTER (DISC PRODUCER)2. POS (POINT OF SALE) RECIEPT AND BANKING PRINTER3. VERSA LASER PRINTER4. 3D PRINTERS (Z CORPORATION)