An input device is a computer hardware device that are used to give data and control signals
In computing, an input device allows the user to feed data into the computer for analysis, storage and process. Input devices accept instructions and allow you to interact with and control it.
Types of Input Devices
Some input devices are used directly by the users to enter data and send commands with a device like keyboard or mouse, while some input devices are used indirectly, when user enters data in computer from observations through a device like scanner or microphone. Smart phone and laptop touchscreens are also input devices, as touchpads are common substitutes of mouse.
Many types of input devices has grown in recent years. Followings are some examples of input devices.
Keyboard is one of the most common and popular input devices used to input data and commands to the computer. Even though many other things now exist, but keyboard sustains the primary input device in most computing scenarios, both home and commercial.
A laptop keyboard is more compact than a desktop keyboard to make the laptop smarter. Smart phones and tablets use on-screen keyboard to input data and select commands.
Keyboard is connected to the computer through USB or Bluetooth. The shape of the keyboard is like a traditional typewriter, although there are some additional keys to perform additional functions. Now keyboards are available with 84 keys to 108 keys for windows and internet.
- Typing Keys
This keys include the letter keys A-Z and digit keys 0-9. These keys generally give the same layout as that of typewriter.
- Numeric Keypad
Numeric keypad consists of a set of 17 keys, which is used to enter the numeric data and cursor movement. These keys are laid out same as that of most adding machines and calculators.
- Function Keys
The twelve function keys are available at the top of the keyboard arranged in a row. Each function key is used for a specific purpose and has a unique meaning.
- Control Keys
These keys give cursor and screen control through four directional arrow keys. Control keys consist of Home, End, Insert, Delete, Page up, Page down, Control (ctrl), Alternate (alt) and Escape (esc).
- Special Purpose Keys
Keyboard also has some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab and Print Screen.
A mouse is the most popular electro mechanical, hand held input device. It is used as a pointer to control the cursor and coordinates. It can be wired or wireless having a small palm size box with a round ball at its base, which senses the movement of the mouse and sends signals to CPU when the mouse buttons are clicked. The mouse makes it easier to navigate menus by clicking on them.
Normally it has two buttons called the left and the right button with a wheel between the buttons. It can perform the following functions.
- Control the position of the cursor
- Selecting commands
- Moving icons
- Open a program
- Drag and drop
- Resizing the window
- Perform other functions with the help of additional buttons
Microphone is an input device, used to input voice and music into the computer that is then stored in a digital form. The addition of a microphone facilitates the people to dictate documents to their computer, record sound, and have long distance conversation. But the voice communication is more complex than information through keyboard. Two types of microphones are available: Desktop Microphone and Hand held Microphone. The microphone is used for various functions like:
- Audio for video
- Computer gaming
- Online chatting
- Adding sound to a multimedia presentation
- Recording musical instruments and music mixing
- Recording voice for dictation and singing
- Voice recorder
- Voice recognition
- Voice over internet protocol
Scanner is an input device, which reads hard copy images and converts them into a digital form. Scanner works more like a photocopy machine. It scans documents and transfers them in digital file.It is connected to the computer through USB.
Scanner is used when some data is available on the paper and it is to be transferred to the hard disk of the computer for further operations. This data can be edited before printing with added OCR software.
There are different types of scanners are available in the market. For example, Flatbed Scanner, Sheet fed Scanner, handheld Scanner and Card Scanner.
05) Light Pen
Light pen is a pointing device similar to a pen that utilizes a light sensitive detector to select objects or draw pictures on the display screen. In light pen, there is a photocell and an optical system placed in a small tube. When the tip of a light pen is moved over the monitor screen and the pen button is pressed, its photocell sensor detects the screen location and sends the signals to the CPU.
06) Digital Camera
Digital camera is an input device that takes pictures digitally and stores them as data on memory cards. It has an LCD screen which provides preview of images. Digital cameras have become more popular than film cameras because of the following features.
LCD Screen: Because of LCD screen users can view photos and videos immediately.
Storage: Digital camera can store thousands of pictures.
Picture Development: Through picture development feature, users can choose and decide which picture to develop.
Size: Digital camera is small in size, so takes less space and can be carried easily.
07) Track ball
Track ball is an input device that is generally used in notebook or laptop computers instead of a mouse. This is a half inserted ball and by moving your thumb, finger or palm of your hand on the ball, the pointer can be moved.
Because track ball is static so it does not require much space to use it. It comes in various shapes like a ball, a button or a square. Track ball can be placed on any type of surface including your lap.
Digitizer is an input device which converts analog data into digital form. Digitizer converts the signals from television or camera into numbers and stores them in computer.
They are used to create a picture of whatever the camera had been pointed at and then stores into binary inputs. A graphic tablet is used as digitizer for drawing and image manipulation.
09) Optical Character Reader
OCR is an input device that scans the printed text optically, converts them into a machine language and stores in the system memory.
10) Magnetic Ink Card Reader
MICR input device is mostly used in banks to process cheques. The bank’s code number and cheque number are printed on the cheque with a special magnetic ink that are machine readable. The main advantage of MICR is that it is fast and accurate.
Touchscreen is a unique type of input device in which users interact with a computer by using their fingers. It is mainly used in laptops, smartphones, tablets and cash registers.
12) Biometric Devices
Biometric device is also an input device used to enter biometric data into a computer by scanning face, hand, finger or voice.
13) Barcode Reader
Barcode reader also known as Barcode scanner, is an input device. It is used as point of sale scanner and for reading barcoded data which is generally used in labelling goods or numbering the books. It can be handheld scanner or stationary scanner.