various input devices

Input devices

The main function of the input device is to enter the data in the computer. The various examples of input data are a mouse, keyboard, light pen, etc.

Mouse

The mouse is found on every computer. It is an integral part of it. It is a  pointing device. The main principle it works on is point and click. The mouse uses the trackball to give the motion to the pointer displayed on the screen. Usually, for the windows based programs, a mouse is used. Nowadays wireless mouses are becoming more popular among people.

Keyboard

The keyboard is used to enter all the data into the computer. It directs the computer through instructions. Normally keyboard has 104 buttons called the keys. You can do various tasks through the keyboard. You can program, type, etc through keyboard only.

Scanner

The scanner is used to store photographs, picture, diagrams into the computer. It saves the image in the form of a file by reading it.

Touchscreen

Touchscreen monitors are becoming more and more popular. It requires putting the input to the computer through the touch by your finger, pen, stylus, etc. You can give any sort of information to the computer by touching it.

Light pen

A light pen is another pointing device that can be used in the computer. It is normally like a pen and is used to directly point at the objects seen on the screen. You can also draw various objects on the computer screen through a light pen.

 Light Pen : This is an input device which is used to draw lines or figures on a computer screen. It’s touched to the CRT screen where it can detect raster on the screen as it passes.

Optical Character Rader : It’s a device which detects alpha numeric characters printed or written on a paper. The text which is to be scanned is illuminated by a low frequency light source. The light is absorbed by the dark areas but reflected from the bright areas. The reflected light is received by the photocells.

 Bar Code Reader : This device reads bar codes and coverts them into electric pulses to be processed by a computer. A bar code is nothing but data coded in form of light and dark bars.

 Voice Input Systems : This devices converts spoken words to M/C language form. A micro phone is used to convert human speech into electric signals. The signal pattern is then transmitted to a computer when it’s compared to a dictionary of patterns that have been previously placed in a storage unit of computer. When a close match is found, the word is recognized.

 Digital Camera : It converts graphics directly into digital form. It looks like an ordinary camera, but no film is used therein, instead a CCD (changed coupled Divide) Electronic chip in used. When light falls, on the chip though the lens, it converts light waves into electrical waves.