Computer Input Devices

Computer input devices are the components that have been used to pass data into a computer to process and provide the desired output. The input data could be letters, numbers, images or sound.

Most of the computer input devices are common to home or office environments. However, there are devices that are not commonly available.
General Computer Input Devices
Keyboard
Mouse
Joysticks
Scanners

Special Computer Input devices
Touch screens
In touch screens, users have to press (touch) areas on the screen to pass data. A typical usage of the Touch Screen technology is some Bank ATM machines.

Smart Cards
This input device stores data in a microprocessor embedded in the card. This allows information, which can be updated, to be stored on the card. This method is used in store cards which accumulate points for the purchaser, and to store phone numbers for cellular phones.

Light pen
A Light Pen is a pointing device shaped like a pen and is connected to a VDU. The tip of the light pen contains a light-sensitive element which, when placed against the screen, detects the light from the screen enabling the computer to identify the location of the pen on the screen. Light pens have the advantage of 'drawing' directly onto the screen, but this can become uncomfortable, and they are not as accurate as digitising tablets.

OCR (Optical Character Recognition)
OCR is designed to translate images of typewritten text (usually captured by a scanner) into machine-editable text, or to translate pictures of characters into a standard encoding scheme representing them in (ASCII or Unicode). OCR began as a field of research in artificial intelligence and machine vision. Though academic research in the field continues, the focus on OCR has shifted to implementation of proven techniques.

Optical Mark Reader (OMR)
The Optical Mark Reader (OMR) can read information in the form of numbers or letters and put it into the computer. The marks have to be precisely located as in multiple choice test papers.

Bar Code Reader
You might have seen bar codes on goods in supermarkets, in libraries and on magazines. Bar codes provide a quick method of recording the sale of items. A bar code is a pattern printed in lines of differing thickness. The system gives fast and error-free entry of information into the computer.

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