Input and output devices can be classified into several groups. Input devices take in data and include touch screens, magnetic stripe readers, barcodes scanners, OMR devices, OCR devices, and MICR devices. Output devices display or print data and include monitors like CRT, TFT, LCD and LED displays as well as printers like inkjet printers, laser printers, and dot matrix printers. Other output devices are plotters and multimedia projectors.

2. INPUT DEVICES
Input devices are the devices which take in data. The Input devices can be classified
into 7 groups, they are:-
 Touch Screens
 Magnetic Stripe Readers
 Barcode Scanners
 OMR Devices
 OCR Devices
 MICR Devices

3. TOUCH SCREENS
 Selection is done without need of pointing device(simply touching the
icon /button)
 Used at petrol stations, ATMs, point of sales terminals, airports,
interactive boards, PDAs.
 Advantages- Faster entry of data, tamper proof.
 Disadvantages- Limited options, frequent uses can lead to health
problems and issues

4. SOME TOUCH SCREEN DEVICES

5. MAGNETIC STRIPE READERS
 Used at the back of all the credit cards
 Security cards for the entry to the building
 Advantage: Fast input, error free

6. SMART CARD READERS
 Contains chip to store data
 Data update is possible
 Used in identity cards
 Advantages: Reduces cash transaction
 Disadvantage: If the card gets lost then it may lead to identity theft

7. BARCODE READERS
 Used to read information in bar-coded format
 Used in supermarkets, library, etc
 Advantage: Faster data entry
 Disadvantage: Expensive system to the administrator

8. OMR DEVICES
 OMR(Optical Mark Recognition)
 Used to read marks written by pen/pencils such as questionnaires, multiple
choice examinations, forms, etc
 Advantage: Fast input, accurate
 Disadvantage: Forms need to be designed very carefully, time consuming as
need to be checked manually.

9. OCR DEVICES
 OCR(Optical Character Recognition)
 Basically a software that converts scanned text into computer readable format.
 Used in processing of passports and identity cards
 Advantage: Faster data entry, less errors
 Disadvantage: Not accurate in reading.

10. MICR DEVICES
 MICR(Magnetic Ink Character Recognition)
 Reads characters printed in special ink(iron particles)
 Used to process cheque in banking operation
 Advantage: Secure as printed characters which can’t be altered, less errors, data
can be read if overwritten
 Disadvantage: Only certain character can read expensive

13. OUTPUT DEVICES
 Monitors: CRT, TFT, LCD, LED
 Printers: Inkjet, Laser, Dot-Matrix Printers
 Plotters
 Multimedia projectors

14. CRT(CATHODE RAY TUBE)MONITOR
 Less expensive, used with light pens, uses electron gun-phosphor screen
 Advantages: Produces good quality images, angle of viewing is better, supports
light pen
 Disadvantages: Very heavy, consume more power, runs very hot, flickering can
lead to headache

15. TFT(THIN FILM TRANSISTORS)
 Tiny pixels made up of transistors controlled by microprocessor, each pixel has
three transistors.
 Advantages: Lightweight, less glare than CRT, less radiation, consumes less
power, do not generate heat compared to CRT.
 Disadvantage: Angle of viewing, expensive, not suitable for using light pen

16. LASER PRINTER
 Used in offices for high quality output. They are faster
 Advantage: Fast for high volumes, high quality
 Disadvantage: Expensive, particular type of paper size and sheets can be used,
health hazards, heavy

17. INK JET PRINTERS
 Used for cost effective good quality output at home, offices, etc.
 Advantages: Less expensive, portable, light weight
 Disadvantage: Slow as little buffer capacity, ink can smudge , ink cartridges run
out very quickly

18. DOT- MATRIX PRINTERS
 Type of impact printer, used for low-quality output in banks, post offices,
railway tickets.
 Advantage: Less expensive, carbon copies can be produced, use of continuous
stationary.
 Disadvantage: Noisy, slow, not good for images

19. 3-D PRINTERS
 Used to produce 3-D models (prototypes) using modified inkjet
technology(Tomography). Thin layers of fine powder(plaster, resin and starch) is
used to make 3D models
 Advantage: Money saving, gives better idea of end product, powder can be
produced/re-used.
 Disadvantage: Expensive, slow, requires finishing touch on the end products.

20. PLOTTER
 Used for making large drawings and images(blue prints of building, factories,
etc)
 Advantages: High quality images, huge products
 Disadvantage: Slow, expensive

21. MULTIMEDIA PROJECTORS
 It magnifies and project the signals onto a big screen received by TV,DVD
 They are used for training advertising presentations when large number of
audience is present. Home cinema systems
 Advantages: Useful for much larger number of audience, number of need
several computers to use for one.
 Disadvantage: Fuzzy, blurred images, expensive, setting up a projector is
difficult