Input Devices

1. Input Devices Nikki Law 4D 30

2. Input devices • The hardware that allows users to enter data • e.g. keyboard, pointing devices

3. Inputting information • Keyboard converts keystrokes into corresponding electrical signals • Pointing Devices allow users control the crusor or pointer on a graphical user interface (GUI) common pointing devices include mouse, trackball, touchpad, track point, joystick, touch screen and graphics tablet.

4. Mechanical Mouse has a ball on its underside, tracks the direction in which the ball is rolling Optical Mouse has an optical sensor which detects its movement

5. Joysticka pointing device designed for playing computer games • Touchpadcontrol the movement of the screen pointer by dragging your fingertip

6. Track Pointit is pressure-sensitive, allowing you to move the pointer in the direction • Trackballthe buttons next to the ball work in same way as the button on a mouse

7. Touch Screen a video display which has a transparent, touch-sensitive layer. • Digitizing Tableta graphical tablets, allow users to draw and sketch directly into a computer

8. How can a scanner work? • Work like photocopiers • Projects light onto a scanned object e.g. paper or slide • Captures the reflected light and interprets it as a pattern of coloured dots • Sharpness is determined by the resolution>dpi (dots per inch), colour depth and accuracy

9. Optical Readers • Barcode readersa mini-scanner which capture images of bar codes and translate them into number • Optical Mark Readersused with optical mark recognition (OMR)applied on MC answer sheets, course registration forms and etc.

10. Biometric devices • Translate the characteristics of a person into a digital code • Store as a records in computer , once the inputted digital code matches a record in the computer , the identify of the individual is confirmed Fingerprint scanner Hand geometry system Iris recognition system

11. Microphones • Allow users to record sound into a computer, usually connected to a sound card on the motherboard • Save as a file , used with speech recognition software • Microphones are a type of transducer - a device which converts energy from one form to another. Microphones convert acoustical energy (sound waves) into electrical energy (the audio signal).

12. The diaphragm. This is a thin piece of material (such as paper, plastic or aluminium) which vibrates when it is struck by sound waves. In a typical hand-held mic like the one below, the diaphragm is located in the head of the microphone. 1.When the diaphragm vibrates, it causes other components in the microphone to vibrate. 2.These vibrations are converted into an electrical current which becomes the audio signal.

13. Digital Cameras and Digital Video Camcorders Digital Camerasuses a light-sensitive processor chip to capture scenes and turn them into digital images large number of light-sensitive photosites in light-sensitive processor chip, the higher the resolution of the digital images

14. Digital Cameras and Digital Video Camcorders Digital video camcorderalso use a light-sensitive processor chip to capture the moving images and store them as a sequence of high-quality digital images