Keyboard Input Device Defination, History, Features, Uses, Classification, Port Details Hardware & networking

Definition

A computer keyboard is an input device. It used to enter characters and functions into the system by pressing buttons or keys. It is a peripheral device that used for the user to communicate with a computer. Now a days keyboard usually have 105 to 112 keys. The keyboard looks like a typewriter and its keys are arranged like a typewriter.

Table of Content:

Definition
History of Keyboard
Keyboard features
Keyboard uses
Different types of keyboard keys
Function of keyboard keys
Classification of keyboard
Port and Connector

However, keyboards have many different keys that ae used to give specific commands to the computer. English letters, numbers, various symbols, and signs are printed on the keyboard. We press them to instruct the computer.

Microsoft and Logitech are some of the most popular physical keyboard manufacturer companies.

History of Keyboard

The first QWERTY keyword was invented by American inventor Christopher Latham Sholes in 1878. Who invented by taking inspiration from Typewriter, with the help of their mates Samuel W Soule and John Pratt.

Keyboard Full Form:

keyboard stands for

K - Keys

E – Electronic

Y – Yet

B - Board

O – Operating

A - A to Z

R - Response

D - Directly

Keyboard Features

· An instruction can be entered directly into the computer through the keyboard.

· Almost all ‘keys’ on keyboard have dual functions.

· Keyboard is cheaper than other input devices, hence its practical cost is also low.

Uses of Keyboard

Input Data
Type Numbers
Text Chatting
Type Special character
Types computer short cut keys
Print Screen
Scroll Lock
Pause
Brightness up & down
Volume up & down

Keyboard keys can be divided into four types---

Alphanumeric Keys:

Every keyboard contains a set of keys known as the alphanumeric keys. The term "alphanumeric" refers to either letters or numbers, but not symbols or command keys. With these keys we can type English letters A-Z and 0-9 numbers.

Function Keys (F1 – F12):

Many computer keyboards have "function keys," beginning with the letter F. They're typically located at the top of a keyboard. These keys can be used to perform various functions in different software. Since they are software dependent, they are called soft keys. For

example:- F1 keys is usually for help. Again F5 keys is used to refresh Windows Memory.

Cursor Movement Key:

The four keys, the right and left arrows and the up and down arrows are collectively called the movements keys.

Special Character Keys:

Some keys on the keyboard are used for special functions, so these keys are called special keys.

Some special keys are: Mathematics keys ( +,-,*,/,=,%)

Punctuation Keys (, ; ? : ‘ “ ! . )

Others keys ( @, #, $, ^, &, () )

Function of Keys

Caps Lock:

when we press the Caps Lock key, then it activated continuously to write upper case letters. continuously without having to press Shift key we make upper case latter through CapsLock key. Press Caps Lock key it again to turn off this function. Your keyboard might have a light indicating whether Caps Lock is on or off.

Shift:

Shift key will be used combination with a letter for type an uppercase letter and special character. Like:- A,B,C,!,@,#,$,%,^,&,*,(,)

Delete:

This key is used to delete any content, letter, file, media, etc.

Escape:

Cancel a task using this key.

Tab:

This key is used to jump the cursor to a specified character or move it a specified distance.

Ctrl:

This key is used with other keys for special functions.

Example- Ctrl+ s save

Ctrl + C copy

Ctrl + V Paste

Ctrl + X cut

Alt:

This key is used for special operation with other keys. For example – pressing ctrl+ Alt+ Del together can restart the computer.

Space Bar:

This key is used to create a space between two letters or words. For example Rajib Das.

Enter:

This key is used to move the cursor to the next line or execute a command.

Back Space:

Press Back Space to delete the character before the cursor, or the selected text.

Num Lock:

When the Num Lock key pressed, the numbers on the number pad of the keyboard activated. When the Num Lock key is not pressed, it’s the arrows and special keys on the number pad which are active. The number pad is a block when numeric key turned off condition.

Home:

Using this key we can move the cursor to the first character of the line.

End:

Using this key we can move the cursor to the last character of a line.

Insert:

pressing the key switches between two modes when you are typing.

Print Screen SysRq:

When pressing the Print Screen key, it captures an image of your entire screen. Print Screen SysRq key mainly used to take screenshots of the present screen.

Pause:

By using this key, we can stop any of the computer work suddenly.

Classification of Keyboard:

(A) There are 5 types of keyboard as Technology wise like -- (Brief discuss another page)

1. Mechanical Keyboard

2. Hall effect Keyboard

3. Membrane Keyboard

4. Capacitive Keyboard

5. Optomechanical Keyboard

6. Virtual Keyboard

7. Projection Keyboard

8. Flexible Keyboard

(B) There are four types of keyboard as Interface wise like -------- (Brief discuss another page)

PS/2 Keyboard (6 pins)
USB keyboard (4 pins)
Wireless Keyboard

Technology wise:

Mechanical Keyboard: A mechanical keyboard is using spring-activated switches. computer keyboards often employ rubber dome switches. As the name through we know, these are constructed with a sheet of rubber domes above electrical switches.
Hall effect Keyboard: The Hall Effect is a displaced electrons in an electric current caused by an electromagnetic force. That electromagnetic force being a magnet. The electric current anything that conducts electricity. A magnet has an invisible “magnetic” field that radiates from its core. Like steel, but not aluminum. It make of “Hall Sensors” to perceive keypresses.
Membrane Keyboard: A membrane keyboard is a computer keyboard whose "keys" are not separate, moving parts, as with the majority of other keyboards. Membrane keyboard keys that makes contact with a circuit board when the key is fully depressed. Also called a "dome switch keyboard.
Capacitive Keyboard: A capacitive keyboard is a keyboard that uses a change of capacitance on a keyboard's capacitor. This type of keyboard provides functionality similar to a mechanical keyboard that its internal structure makes depressing a key quicker and quieter.
Optomechanical Keyboard: This type of keyboard have a led which generate light when proper electric power is applied to the Led. two metal contacts touch when you press down on switch. opto-mechanical switches have a beam of light that triggers the switch.
Virtual Keyboard: This types of keyboard is a software-based keyboard that enables users to type without e need a physical keyboards. this keyboard is use of a touch screen featured in newer laptop releases and tablet computers even we type through mouse. These types of keyboards have characters, including numbers, letters, punctuation, and symbols. This type of keyboard to make secure / prevent of the keystroke for the hacker Side when we payment online or type user name & password.
Projection Keyboard: This is a keyboard design in which the keys are a hologram projection into any surface. The device detects what we type on the flat surface and records keystrokes accordingly. It is connected through Bluetooth to your mini PC, tablet computer or even smartphone.
Flexible Keyboard: These keyboards are very eye-catching keyboard, stand out for their appearance and the material with which they are make by rubber, silicon and plastic. they can be rolled, or folded any space & any angle transported without taking up much space and in tiny places.

Interface wise:

PS/2 Keyboard: The PS/2 (Personal System/2) port is a 6-pin mini-DIN connector used for connecting keyboards and mice. It was developed by IBM. it was introduced in 1987. The PS/2 mouse connector replaced of the older connector DE-9 RS-232 "serial mouse". while the PS/2 keyboard connector replaced to the larger 5-pin/180° DIN connector used in the IBM PC/AT design.
USB keyboard: A USB keyboard is a standard keyboard that most useful and popular port of our computer. USB stands for Universal Serial Bus. USB keyboards come in various shapes and sizes. The standard size of keyboard for desktop PCs is 17 inches. It typically comes in a 104-key or 108-key layout, which includes a numeric keypad.
Wireless Keyboard: This type keyboard have communicates with desktops or laptops with the help of radio-frequency, such as Bluetooth or Wi-Fi, or infrared technology. This is very useful because there is no headache of wires. This is most convenient for travelers because they don’t need to adjust their cables present day.

Port and Connector:

PS/2 Port: PS/2 stand for Play station 2. This types of port used in keyboard before in 1996. It has 6 pins. PS/2 keyboard connector port mentions the purple color. Pin 1 can send data, pin 2 have been no connection, pin 3 have connected ground, pin 4 can send +5V DC, pin 5 send clock timing, and pin 6 have been no connection.
USB Port: USB stand for Universal Serial Bus. It is invented by compaq in 1996. Now a days usb version 3.1 can be send data 10 Gbps better then ps/2 connector. So many keyboard has been found usb types. It has 4 pins and wire color are black, green, white and red.