Input Devices Of Computer

INPUT DEVICES OF COMPUTER


Keyboard

The keyboard and mouse are the most widely used input devices at the moment. Keyboard is designed for people with special needs.

Light pen
Another input device is called a light pen which can be used to point at a monitor. It is similar function to a mouse. A touch sensitive screen is a method of input based on touching a specially designed screen in particular places.

Barcode scanners


It is very popular input device in supermarkets and stores. These devices scan barcodes which identify products. This is a form of OCR. The barcode is translated to a number which can be used by the computer to identify the product and look up its price in a database. In addition the software can keep track of stock levels by recording the number of sales of each item.

Optical character recognition(OCR)
An OCR device can scan a document and recognise characters. Text had to be printed in a special OCR font for OCR to operate but nowadays OCR can handle almost any font. The advantage of OCR for companies is that when statements are returned with payments, they can be scanned in and the customer accounts automatically credited.


Mouse

The mouse is used as a pointing device and to select options from menus. A tracker ball is used for the same purpose as a mouse and is popular on laptop computers.

Optical mark render
A less sophisticated but similar device is an optical mark reader which can scan a specially designed from and recognise the presence of marks in particular positions. One use for such a device is in lottery games machines where a user marks numbers on a pre-printed form which is then read by an OCR reader connected to a lottery computer.

Magnetic ink character recognition(MICR)
This is similar to OCR but this time the characters are not scanned optically. Instead they are scanned magnetically as they have printed with magnetised ink, each character having a very distinct shape. This is used on cheques by banks, to encode bank account numbers.

Image scanners

Image scanner is devices which scan an image (document, photograph) and produce a digital version of the image i.e. the image is stored as a sequence of binary numbers. Special software can then display the digital version of the image on a monitor. They effectively photocopy the images into computer. This type of technology is very useful for storing legal documents, application forms and anywhere there is a requirement to access the contents of an original document very quickly.

Cards
Whole range of cards is available such as ATM and credit cards which encode information magnetically. These cards can be read by card readers and allows you carry out various transactions such as paying for goods or obtains cash.