 Output Devices Output Devices  Types of Output Devices Types of Output Devices MONITORS PRINTERS  Impact Printers Impact Printers Dot Matrix Daisy Wheel Line Printers

 An output device receives information from the computer and translates it from machine language to a form that humans can read or so that another machine can read the information.  Output that is readable by the user can be categorized into two categories: hard copy or soft copy.  Hard copy is a relatively permanent form of output that can be read immediately or stored for later use, such as paper. Printers are the most common hard copy output devices.  Soft copy is a transient form of output, for example, text on a screen display. It is lost when the computer is turned off unless it is saved in the main memory or on a disk BACK

 MONITORS  PRINTERS  PLOTTERS BACK

 Monitor :Monitor is an output device that display information. It can display text as well as graphic images in color or black & white while based on monitor type.  Based on color Monochrome: It display two colors, one on the foreground and one on the background. The colors can be black and white, green and black or amber and black. Gray-scale: Special type of monochrome monitor capable of displaying different shades of gray.  Multi-Color: They are called RGB monitors, they accept three separate signals-Red, Green and Blue. A multi-color monitor can display any color.  Based on signals Digital monitor: It accepts digital signals rather than analog. The term digital refers to the type of input received from the video adapter. Digital monitors are fast and produce clear images. Eg: Flat-panel display which uses Liquid Crystal Display technology.  Analog monitor: This is the traditional type of color display that has been used for years in televisions. In reality all monitors based on CRT(Cathode Ray Tube) technology are analog. The monitor consumes much space. BACK

 Printer is the most important output device,which is used to print information on paper. most c

 Printers can be divided into two distinct categories :  IMPACT PRINTERS: The printers that print the characters by striking against the ribbon and onto the paper.In these printers, there is a mechanical contact between the print head and paper.  NON IMPACT PRINTERS: The printers that print the characters without striking against the ribbon and onto the paper In these printers, there is no mechanical contact between the print head and paper. BACK

 The printers that print the characters by striking against the ribbon and onto the paper.In these printers, there is a mechanical contact between the print head and paper. BACK

 Print head contains a vertical array of pins.  As the print head moves across the paper, selected pins fire against the ribbon.  Each character printed is in form of pattern of DOTs.  The more pins the print head has the better will be the printing quality. BACK

 The printer look like daisy contains a disk made of plastic or metal on which letters and symbols are placed on each patel.  When printer needs to print a character, it sends the signal to mechanism called printhead, the printhead rotates the daisy wheel until the desired letter is in place and facing the paper.  Then a electromechanical hammer called Solenoid strikes the back of the character contained petal, forcing the character to hit an ink ribbon, leaving an impression of the character on the paper.  Daisy wheel printing speed is measured in character per second and standard speed is 10 to 50 characters per second.  They are printers of letter quality type.  It cannot print graphic images. They are noisy and slow. BACK

 Line Printers are the printers which print one line at a time.  These are Impact printers for producing very large volume paper output.  Speed is 300 to 3000 lines per minute.  The most commonly used printers in this category are WHEEL PRINTER DRUM PRINTER CHAIN PRINTER

 It has characters fixed in type assembled on a chain.  With the rotation of band, hammer is activated when desired character comes in front of it.  Speed varies from 400 to 3000 lines per minute.

 The Wheel printer has 120 rotating wheels.  There are 48 characters on each wheel.  At the time of printing, all the 120 print wheels are positioned for the data to be printed.  In this case, complete line of 120 characters is printed at one line.

 It consist of cylindrical drum on which characters are embossed for each & every print position on line.  Drum is rotated at very high speed.  Character is printed by striking hammer against embossed character on surface.  Speed is 300 to 2000 lines per minute.  They are very fast in speed. BACK