Input devices

Input devices

1. Bar code reader

   • Laser reads light reflected from black & white lines, binary code represents product information which can be stored in a database
     • Retail sales, library loans, postal package tracking, stock control, ID cards
     • Fast input, accurate
     • Data on barcode cannot be edited

2. Digital Camera

   • Light focused via lens onto a sensor which is made of a grid of tiny light sensitive photosites (pixel), pattern of light associated with image is stored digitally on memory
     • Everyday, engineers, estate agents, speed
     • Used flexibly, modified, attached as a file
     • Memory heavy, Quality of output depends on quality of paper and printer

3. Keyboard

   • Translates key selections into digital format
     • Enter data, input text directly into a computer, send instructions and commands
     • Most common method of inputting text based data
     • Transcription errors are common, time consuming & dependant on typing skills, contribute to RSI if overused

4. MICR

   • Data is printed in the form of specially designed character, ink used to print these characters contains a magnetic substance
     • Banks use this approach to process cheques, key details are stored on the magnetic strip at the bottom
       • Quick and highly efficient, humans as well as machines can make sense of the data, resistant to forgeries
       • Limited applications, decline of cheque use

5. Smart cards

   • Magnetic strip cards store encoded data about the cards user, when swiped translated into data
     • Store personal details on debit cards
       • Cards increasingly used for transactions, contain more data, robust and more secure
       • Can be stolen

6. Pointing devices

   • Mouse ball sends positional information to the computer which is then translated into movements of a pointer on screen
     • Communicate with GUI
       • Required by GUI, constant developments in functionality
       • Experts tend to use keyboard short-cuts, hand to eye coordination is an issue for some

7. OCR

   • Reads the reflected light from characters on a page
     • Hard copy to digital, input data capture forms
       • Faster than key to disc
       • Can misread letters, not good for hand written text

8. OMR

   • Read marks made at specified points on a specially designed form
     • Lottery, examination papers, school registers
       • Avoids need for file transfer, can be extremely quick method of entering large amounts of data
       • Limited range of responses, incorrect marking leads to rejection

9. Sensors

   • Read changes in the environment around them
     • Control systems, room temp/humidity
       • Necessary element of any control system, data captured cheaply with little effort
       • Limited in the type of data collected, can misread changes

10. Touch screens

    • Values associated with different positions associated with different positions on a VDU via a "grid" of infrared beams across the front of the screen
      • Museums, galleries, small children ,disabled fast food
        • User friendly
        • Limited number of values

11. Speech input

    • Data inputted in audio form, via microphone or audio tape
      • Dictate text directly into word processing app, control systems, security systems
        • Speak much quicker than even the most skilled typists
        • Interpreting human language is complex and not uniform

12. IWB

    • Values associated with different positions associated with different positions on a VDU via a "grid" of infrared beams across the front of the screen
      • Museums, galleries, small children ,disabled fast food
        • Limited number of values
        • User friendly