Output Devices

Output Processed input data into a useful form is called output Computer generates several types of output depending upon the hardware and software used and requirements of the user View output on the screen Print it on printer Hear it through speakers or headsets

Classification of Output Softcopy Output Hardcopy Output Sound Output

Output devices Hardware component used to get output from the computer Number of output devices are available Most commonly used output devices include: Monitor Printer Speaker Head set Fax Machine

Monitor Most popular and commonly used output device Consists of screen and an electronic component that produce the output on the screen for a temporary period Output received on the screen is called soft copy Display texts, graphics and video information Categories of Monitor: Monochrome Monitors Grayscale Monitors Color Monitors

Types of Monitor CRT Monitors Flat-Panel Monitors

CRT Monitors Similar to standard television Contains a Cathode Ray Tube which is a large scaled glass tube Contains electronic gun

CRT Monitors http://www.yourdictionary.com/cathode-ray-tube

CRT Monitor http://www.bombayharbor.com/Product/16877/15inch_Normal_Crt_Monitor.html

CRT Monitor Size Measured diagonally, in inches across the front of the screen Available in various sizes i.e. 15,17,19, 21 and 22 inches

Measuring Quality of CRT Monitor Resolution Dot Pitch Refresh Rate

Video Card Many CRT monitors use an analog signal to create an image on the screen Video card is installed on the motherboard Converts the digital output from the computer into analog video signal

Video Standards Standard Resolution Maximum Color Monochrome Display Adapter (MDA) 720 X 350 1 Video Graphic Array (VGA) 640 X 480 16 Extended Graphics Array (XGA) 1024 X 768 256 Supper Video Graphics Array (SVGA) 800 X 600 1280 X 1024 1600 X 1200 16.7 million Beyond SVGA 1920 X 1440 2048 X 1436

Flat Panel Monitor Also called LCD Monitor Uses a Liquid Crystal Display to produce output on screen Has fluorescent tube that emit light waves towards the liquid crystal cells Takes less desk space Consumes less power

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Flat Panel Monitor http://smashedtech.com/how-lcd-works/

Categories of LCD Active Matrix LCD Passive Matrix LCD

Touch Screen Monitors Special monitors through which input data is directly entered by touching the screen with user fingertip Use sensors in the computer screens to detect the touch of a finger Example: ATM

Printers Most commonly used output device used to get prints of documents on the paper Output printed on the paper is called hardcopy Printer is connected to a parallel port or a USB port of the system unit by a cable Classification of printer based on printing mechanism: Impact Printer Non Impact Printer

Impact Printers Print character and graphics on the paper with the strikes of hammer on a ribbon Example: typewriter Each hammer is embossed with the shape of alphanumeric character Shape is printed on the paper through inked ribbon Most commonly used printer is dot matrix printer

Non Impact Printers Produce the output on the paper without striking the paper Use electrostatic, chemicals, inkjet and thermal technologies for printing Main features: Faster than Impact Print high quality output Produce no noise during printing Examples: Laser Printer, Inkjet Printer

Dot Matrix Printer Impact character printer Print one character at a time Prints output on the paper by using the mechanism called print head Contains matrix of tiny pins arranged in row and columns Can use tractor feed paper Print head contain 9 to 24 pins Speed is measured by the number of characters per second

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Inkjet Printer Non Impact character printer Prints one character at a time Has fine spray nozzle that creates the image of character or graphics on the paper by spraying tiny or small drops of ink onto the paper Speed is measured in terms of number of pages per minute it can print

Inkjet Printer http://www.epson.com/region/US/Error200.html

Laser Printer Fastest and high quality non impact printer More expensive Work like photocopier Creates image on the paper using a laser beam and powdered ink, called toner

Laser Printer https://en.wikipedia.org/wiki/Laser_printing

Plotters Special output devices used to produce hard copies of graphs and design on the paper Typically used to print large format graphs or maps such as construction maps or engineering drawings Two Types: Drum Plotters Flatbed Plotters

Drum Plotters Also known as roller plotter Consists of drum or roller on which a paper is placed Drum rotates back and forth to produce the graph on the paper Also consists of mechanical device known as robotic drawing arm that holds a set of colored ink pens or pencils

Flatbed Plotters Also known as Table Plotter Plots on paper that is spread and fixed over rectangular flatbed table Uses two robotics drawing arms

Flatbed Plotters Also known as Table Plotter Plots on paper that is spread and fixed over rectangular flatbed table Uses two robotics drawing arms

Flatbed Plotters http://www.weiku.com/products/11482165/Graphtec_FC2250_180ES_Flatbed_Plotter_with_Electro_Static_Charge.html http://cinict.blogspot.com/p/unit-2-input-and-output-devices.html

Other Output Devices Data Projectors Speakers Computer Output Microfilm and Microfiche

References Introduction to Information Technology by Riaz Shahid, CM Aslam and Safia Iftikhar The Concepts of Information Technology by Imran Saeed, Ahsan Raza, Tariq Mehmood and Zafar Hussain