Keyboard is an input device which is similar to typewriter and has many
additional keys. Keyboard has 104 keys including functional keys, symbols,
control keys, arrow keys, and it also have LED indicators. The following image
of an Qwerty keyboard shows all the keys.
day USB, bluetooth keyboards are used with the coputers. But eariler the
computer were using PS/2, serial as keyboard interface. In keyboards,
alphabets, numbers and symbol are printed on the keys. The keys in keyboard are
not only used to display the aplhabets and numbers but also use to pas commands
to the computer.
There are two types of keyboards.
1. Wired Keyboards: – The wired keyboard is day by day
becoming the past but still it is the most preferable keyboard. The wired keyboard
uses AT, PS/2 connectors. The wired Keyboard need the Drivers to operate that
is already installed in the computers. Now days the most commonly use wired
keyboards are USB keyboards. The major Drawback of the wired keyboard is we cannot
use it from distance.
2. Wireless Keyboards: – The
wireless keyboard is now a day’s becoming so popular. A wireless keyboard uses
infrared technology, Bluetooth technology and radio frequency technology. The
wireless keyboards are used with computes, laptops, tablets. Radio Frequency
keyboards transmit data using signal where infrared technology uses light for
data transmission. We can use these keyboards from the distance. Means if we
are using Bluetooth wireless keyboard than we can use it from distance upto the
range of the Bluetooth keyboard.
There are many other keyboards used for
different purpose such as laptop keyboard, gaming keyboards, laser keyboards
and Ergonomic keyboards,
membrane keyboards, etc. Below each key there is a small hole and a small
cylinder bar of same size. When the key is pressed, the bar is pushed down and
touches the contact layer below. Inside the bar there is a small rubber that
pushes back the key up. This is how the system is able to know which key is
pressed. There are some light indicators with some keys such as num keys caps lock