input devices

Input Devices of Computer

Presented by Ch. Abdul Manan

Learning Outcomes

Students can1. tell the name of input devices2. Indentify the input devices3. tell the function of different input devices

Definition of Input Devices

The devices which are used to enter data and instructions into the computer are called input devices.

Names of Input Devices

1. Keyboard 2. Pointing Devices

i) Mouse ii) Trackball iii)Track padiv) Joystick v) Light pen vi) Digitizer

3. Microphone4. Digital Camera5. Digital Scanner

Keyboard

It is used to enter text and numeric type data.Some special keys used to perform special functions.The buttons on the keyboard are called keys.The standard keyboard is Q,W,E,R,T,Y Keyboard

Pointing Devices

A pointing device is an input device that is used to control a cursor.For Example: Mouse, Trackball, Touchpad, Joystick, Light Pen, Digitizer

Computer Mouse

Mouse

It is used to o control the cursor or pointer.o give commands to the computero create graphics

Trackball

Trackball• It performs functions like mouse• A stationary device• Moveable ball on its top• The ball is rotated or rolled with fingers or palm• The ball is used to control movements of pointer• Trackball also has buttons used send commands• No need of flat surface

Track pad / Touch pad It is a pressure sensitive pointing device Stationary device It has no moving parts A small, flat surface We slide our fingertip to move pointer Pointer moves on the screen Some Touch pads has buttons near the surface Commonly used with portable computerIt can also attached with keyboardBuilt in keboards

Track pad / Touch pad

Joystick

o It consist of a vertical handleo Like gearshift lever mounted on a baseo One or two buttonso Vertical handle used to control movements of pointero Buttons of joysticks are pressed to activate the certain event or actiono Video games and CAD

Joystick

Light Pen

PDA

Light Pen It is a handheld pointing device A light sensitive device or pen like device It is connected to a computer by a wire A photocell on its front end When front of the photocell touched with the monitor screen, it detects a position on display screen The has a button; to select and press PDA and other handheld devices

Digitizer

Digitizer / Graphic Tablet A flat, rectangular, electronic board Each location on the digitizer points to

corresponding position on the computer screen Used to make drawings and maps Stylus and Puck (cursor) are used to trace drawings

and sketches Digitizer converts the movements of stylus and puck

into digital signals that are sent to computer Easy to enter freehand drawing into computer

Microphone

Microphone

Audio input device Use to enter / record sound into computer Main Purpose to provide digital input for multimedia

Digital Camera

Digital Camera It is used to take pictures in digital form Uses a light sensitive processor chip Chip capture photographic images in digital form These images are stored in a small diskette or flash memory chip Then image are loaded into computer for further processing

Digital Scanner

Digital Scanner / Optical Scanner Light sensitive input device It reads images and text printed on the paper The translates into electronic form That can be processed and stored by computer It uses Laser technology to scan the images