Wednesday, 24 July 2013

**INPUT DEVICES (PERANTI INPUT)**

^^ MEANING OF INPUT DEVICES ^^
An input device is any device that provides input to a computer. There are dozens of possible input devices, but the two most common ones are a keyboard and mouse. Every key you press on the keyboard and every movement or click you make with the mouse sends a specific input signal to the computer. These commands allow you to open programs, type messages, drag objects, and perform many other functions on your computer
While most computers come with a keyboard and mouse, other input devices may also be used to send information to the computer. Some examples include joysticks, MIDI keyboards, microphones, scanners, digital cameras, webcams, card readers, UPC scanners, and scientific measuring equipment. All these devices send information to the computer and therefore are categorized as input devices. Peripherals that output data from the computer are called output devices.

 ^^ EXAMPLE OF INPUT DEVICES^^

 MOUSE


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.