Input And Output Devices

1. Scanners

1.1. Two-Dimensional Scanner

1.1.1. Used at airports to read passports

1.2. Three-Dimensional Scanner

1.2.1. Used to create a 3D image of a solid object

2. Barcode readers/scanners

2.1. structure: right-hand and left-hand side separated by guard bars

2.2. application: can be used in supermarkets and libraries

2.3. numbers 0 to 9 are each represented by a unique series of lines

3. Quick Response (QR) Code

3.1. made up of a matrix of filled -in dark squares on a light background

3.2. can hold over 7000 digits

3.3. can be scanned anywhere

4. Digital Camera

4.1. can link to a computer system via USB or bluetooth

4.2. controlled by microprocessor

5. Keyboards

5.1. used for data entry

5.2. connected to computer by USB or wireless connection (touchscreen on mobile devices)

5.3. each character has an ASCII value which is converted to digital signal when pressed

6. Pointing Devices

6.1. allows user to click on an icon

6.2. example: mouse and trackerball

7. Microphones

7.1. used to input sound to computer

7.2. voice recognition and speech recognition system

8. Touchscreens

8.1. allow simple touch on screen

8.2. technologies: capacitive, infra-red and resistive

9. Sensors

9.1. read or measure physical properties

9.2. used in both monitoring and control applications

10. Monitoring applications

10.1. Burglar alarm system

10.2. monitoring patients in a hospital

11. Control applications

11.1. Control of street lighting

11.2. Anti-lock braking systems (on cars)

12. Interactive whiteboards

12.1. allow computer images to be displayed on a whiteboard using digital projector

12.2. allow users to write on the whiteboard

13. Printers

13.1. Inkjet printers

13.2. laser printers

13.3. 3D printers

14. Cutters

14.1. Two-dimensional cutters

14.2. Three-dimensional cutters

15. Acutators

15.1. Used in sensors and devices such as ADC and DAC

16. Loudspeakers/headspeakers

16.1. sound is produced from a computer by passing the digital data through a DAC and then through an amplifier

17. Monitors

17.1. LCD (liquid crystal display/diode)

17.2. LED (light emitting diode)

18. Light projectors

18.1. DLP (digital light projector)

18.2. LCD (liquid crystal display/diode)