Input Devices

Input Devices

1. Keyboard

   • Used mainly for text input
   • Uses physical switches under keys which complete a circuit when pressed thereby sending a signal to the processor
     • Mechanical
       • Found in dedicated desktop keyboards
   • Types of keyboards
     • Concept
     • Brail
     • Ergonomic
     • Virtual

2. Scanner

   • Shines a light onto the subject and redirects it with a combination of lenses and mirrors onto the CCD array
     • The CCD array converts light signals to electrical signals
   • Types of Scanners
     • Flatbed
     • Sheet-fed
     • Drum
     • Handheld

3. Optical mouse

   • Uses an LED light and light detectors to detect movement relative to a surface
   • Works best on mouse pads and non-glossy surfaces
   • Is less likely to fail due to absence of moving parts
   • Types
     • Wired
     • Wireless

4. Joystick

   • Consists of an analog stick that is pivoted on a movable ball
   • Can detect changes in 2 axes

5. Tracker ball

   • Is a sphere that rotates in place within a socket allowing for movement of the mouse pointer
   • Can detect movement about 2 axes

6. Microphone

   • Has a diaphragm that reacts to sounds by moving
     • The coil which is attached also moves
       • This back and forth movement causes creation of an electric current due to presence of magnet