Input devices

Input devices are used to enter data  instructions into the computer. These devices forward data to the processing unit in the machine readable form. Data and instructions entered into a computer through input device are converted into electrical signals by the input devices. Some input devices are discuss below:

Keyboard

Today almost every people  about keyboard. It is a input device which is used to type text on the screen. Many times keyboard can do the work of mouse. It is very like a standard type writer keyboard with a few additional keys. Its presence is noticed by the little cursor blinking on the screen. When a character key is pressed, the point where the cursor is there. In CLI (Command User Interface) programs keyboard play a important role because every command is typed by keyboard. 

Mouse

Basically, Mouse is an input device which is used to moved the cursor or pointer directly on the screen. It is a basic part of computer system. It is a small palm size box having two or more button on the top and a ball at the bottom. This ball secures the movement and transforms it into electrical text, selecting item etc. Today, Mouses are coming in various type i.e., Wireless mouse, wired or simple mouse, laser light mouse. 

Scanner

It is an input device that optically scan images, printed text, hand written text or an object, and converts it to a digital image. It can input data printed on papers directly on the computer. For e.g., if you have photograph and went it to be saved it in the computer disk you can use the scanner which scans the image and transforms the image to the code used by the computer. A scanner creates an electronic form of the printed image or text which can be manipulated, changed and modified according to the requirements. There is a glass window on which paper is scanned. 

Mainly there are three types of scanner are popular today :

Flat bed scanners

Flat bed scanners look like a photocopy machine, which has glass window. On glass window you could place the pictures, documents etc., which is to be scanned. 

Roller type scanners

These scanners uses roller to print a document. It is like a fax machine where the image is passed over a roller and it is captured. 

Hand held scanners

These scanners are generally small in size and portable for small office or other work. To scan the image, you have to hold the scanner in hand and move it over the document and printer to fixed the margin, which is to be inputted into the computer.

Bar Code Reader (BCR)

A Bar Code Reader is an electronic device for reading printed barcodes

i.e., Data are represented in bar code form by the width of the bar and the distance between the lines. The BCR (Bar Code Reader) reads these lines or codes. After scanning it shows the information on the screen. In many product you can see bar codes. These codes are UPC. The UPC, Universal Products Code, is found mostly on grocery items. The vertical bar on the product contain various information such as its brand name, quality, features and other information. The BCR identifies the products and it's information. As the technology increases many things are changed and became new. Bar Code Pro is the latest software available for bar code reading. This software requires 11 digits and checks digits automatically. You can change the height, width of the bars, text, font style and size.(For all the enhanced features in this software it was given the Bar Code Pro).

Optical Character Reader (OCR)

Optical Character Reader is an input device used to read character of special type of font printed on any printed or hand written text written on any paper. It scans the text optically character by character and converts them into a machine readable code and stores the text on the system's memory. The printed characters are examined by passing them under a strong light and a lens system which differentiates lights from inked areas, and a logical system which determines that which of the possible characters is being examined. The Optical Character Reader software and hardware extracts text from the document's image. They can read at a rate of up to 2400 characters per second. The next stage of the OCR processing is the character recognition, which involves features extraction and classification. For example, if the software is confused between a character just like "O" and "0" and the character appears two numbers the OCR will recognize it as a number "0". It also has built in dictionaries and spell checkers to verify the result. 

Camera

Camera is also a input device. Everyone know that camera is used for clicking images etc. There are some categories of camera :

Digital Camera

The digital camera allow you to take best quality photograph and stores the photographed images digitally. These images can be input or transfer in the computer in digital form. These photograph can be printed on the photo paper. Today's studio are using digital cameras to take photograph with computer computer support that are very quick printed on the paper and given to the customer as soon as possible. There fore, a digital camera is known as a data collection device instead of an input device.

Web Camera

A web camera is an input device used with the computer which captures live movements from the front of the computer and also provides them as input to the computer. This camera enables us to take snap or video clipping that can be sent on the internet. It is basically a low cost resolution camera that is specially designed for web operations like video conferencing, video chat etc.

Biometric Camera

Biometric camera is also known as biometric sensor. It is a input device that is used to identify the person on base of his/her biological measurements and identifications. The biometric technology verifies various thing i.e., the identity of a person, checking Dynamic signature, Retinal Scanning, DNA identification, Finger print identification, Face Shape Recognation, Voice Recognition etc.

Touch Screen 

Touch Screen are special type of screens which is designed to recognize the touch on the screen. The screen is made up of a grid of sensing lines. When you touch a part of a screen, the screen determine the location of a touch by matching vertical and horizontal contacts and the desired operation is undertaken. The user can make a selection or move the cursor by touching the screen. Nowadays, touch screens are used in railways, airlines etc., where the users indicate the train or flight name with current location and destination by touching the screens. And then all the possible routed with timing and rates are displayed. Touch screens are also used in smart phones, tablets and laptops. Touch screens takes input that's why it is called input device. 

Magnetic Ink Character Reader (MICR)

Magnetic Ink Character Reader is an input device used for character recognition technology by the banking industry to facilitates the processing of cheques and debit card/credit. The bank's code number and cheques with a special type of ink. On the cheque of bank you will find such characters printed with special type of ink on the bottom raw of the cheque where the cheque number is printed with the magnetic ink that are machine readable. This is read by the Magnetic Ink Character Reader. This technology allows computers to read information such as account number from printed documents. Unlike barcodes or similar technologies, MICR codes can be easily read by humans. 

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