INPUT DEVICES

 

The input unit is formed by the input devices attached to the computer. Ex - Keyboard, Microphone etc. An input unit takes the input & converts it into binary form so that it can be understood by the computer   KEYBOARD   This is most commonly used device which acts as input device. Its structure is like typewriter.It contains no. of  keys which have some specific ASCII values. Like ‘A’ has ASCII value 65. When this is pressed , it is converted into 65 & this 65 is sent to CPU in the form of Binary language (i.e. 1000001). Then operations are done on this data.

MOUSE

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This is a pointing device which contains a roller in its base. When the mouse is moved on any surface, the pointer on the screen is also moved. It contains a potentiometer coupled with the roller. This potentiometer senses the motion of mouse & convert it into digital value. A mouse may contain two or three buttons. 

Now a day's optical mouse are very popular.

 

BAR CODE READER

It is a device which is used to read the code from the products which are usually in the form of Bars. It contains a light sensitive detector which identifies the values of the bars on the product & converts them into numeric code.
These Bar readers are used in Shopping malls in a very large scale.

 

DIGITAL CAMERA

As the name specifies, these camera stores the data digitally, which then can be stored in the computer & can be stored for a long time. But it has very limited storage capacity. These are very popular because of less expensive photographs & Speed.

 

 

LIGHT PEN

It is a pointing device which contains a photocell mounted at its tip. It senses the light from the screen when it becomes closer to the screen, & generates a pulse. So for identifying a particular location on the screen these light pens are very useful. But this is not in very much use these days.

SCANNER

The scanner is an input device like the photocopier machine which makes the electronic copy of the picture or document which can be further edited.

MIC's or MICROPHONES

The scanner is an input device like the photocopier machine which makes the electronic copy of the picture or document which can be further edited.