for 6th graders and above

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