Input Devices

Input Devices

Input devices allow users and other applications to input data and instructions into computer for processing. from external world. The data input to a computer can be in the form of text, audio, video, etc.

Input Devices are perform three main functions :
1. Receive data from user
2. Convert data into binary form [The language of 0 and 1 also called the machine language. Machine language is the only language, a computer can understand directly.]
3. Provide converted data to computer memory for processing.

Input devices are classified as follows—

Human data entry devices
    » Keyboard
    » Pointing devices—mouse, trackball, joystick, digitizing tablet
    » Pick devices—light pen, touch screen

Source data entry devices
    » Audio input—speech recognition
    » Video input—digital camera
    » Scanner—hand-held scanner, flat-bed scanner
    » Optical Scanner—OCR, OMR, MICR, barcode reader

The input is provided to the computer using an input device, and must be translated to a form that the computer can understand. The translation is done by the input interface of the input device.
In addition to the above devices, the input to a computer can also be provided from a storage device on the computer, another computer, or another piece of equipment, such as a musical instrument, thermometer or sensors.

HUMAN DATA ENTRY DEVICES

Input devices that require data to be entered manually to the computer are identified as human data entry devices. The data may be entered by typing or keying in, or by pointing a device to a particular location.

SOURCE DATA ENTRY DEVICES

Source data entry devices are used for audio input, video input and to enter the source document directly to the computer. Source data entry devices do not require data to be typed-in, keyed-in or pointed to a particular location.