Input Devices | Computer Fundamental

Input device enables the user to send data, information, or control signals to a computer. The Central Processing Unit (CPU) of a computer receives the input and processes it to produce the output.

Types of Input Devices

• Keyboard
• Mouse
• Scanner
• Joystick
• Light Pen
• Digitizer
• Microphone
• Magnetic Ink Character Recognition (MICR)
• Optical Character Recognition (OCR)
• Digital Camera
• Paddle
• Steering Wheel
• Gesture Recognition Devices
• Light Gun
• Touch Pad
• Remote
• Touch Screen
• VR
• Webcam
• Biometric Devices

1. Keyboard

Keyboard is a basic input devices that is used to enter data into a computer or any other electronic device by pressing keys. It has different sets of keys for latters, numbers, characters and functions. Keyboard are connected to a computer through a USB cable or a Bluetooth device for wireless communication.

Keyboards are of two sizes 84 keys or 101/102 keys, but now keyboards with 104 keys or 108 keys are also available for windows and internet.

Types of Keyboards

• QWERTY keyboard
• AZERTZ keyboard
• DVORAK keyboard

Types of keys in Keyboards

• TYPING KEYS : These keys include the latter keys(A-Z) and digit keys (09) which generally give the same layout as that of typewriters.
• NUMERIC KEYPAD : It is used to enter the numeric data or cursor movement, Generally, it consist of a set of 17 keys that are laid out in the same configuration used by most adding machines and calculators.
• FUNCTION KEYS : The twelve function keys are present on the keyboard which are arranged in a row at the top of the keyboard. Each function key has a unique meaning and is used for some specific perpose.
• CONTROLS KEYS : These keys provide cursor and screen control. It includes four directional arrow keys. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt) and Escape(Esc).
• SPECIAL KEYS : Keyboard also contains some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab and Print Screen.

2. Mouse

The mouse is a hand-held input device which is used to move cursor. It is designed to be used on a flat surface and generally has left and right button and a scroll wheel between them. Laptop computer come with touchpad that work as mouse. Some mouse comes with integrated features such as extra buttons to perform different buttons.

The mouse was invented by Douglas C. Engelbart in 1993. Early mouse had a roller ball integrated as movement sensor underneath the device. Modern mouse devices come with optical technology that controls cursor movements by visible or invisible light beam. A mouse is connected to a computer through different ports depending on the type of computer and type of a mouse.

Types of Mouse

• Trackball Mouse
• Mechanical Mouse
• Optical Mouse
• Wireless Mouse

3. Scanner

The Scanner uses the pictures and pages or text as input. It scans the picture or a document. The scanned picture or document then converted into a digital format or file and is displayed on the screen as an output. It uses optical character recognition techniques to convert images into digital ones.

Types of Scanner

1. Digital Scanner

It has a glass pane and moving optical CIS or CCD array. The light illuminates the pane, and then the image is placed on the glass pane. The light moves accross the glass pane and scans the document and thus produces its digital copy. You will need a transparency adapter while scanning transparent slides.

2. Handheld Scanner

It is a small manual scanning devices which is held by hand and is rolled over a flat image that is to be scanned. The drawback in using this device is that the hand should be steady while scanning; otherwise, it may distort the image. One of the commonly used handheld scanners is the barcode scanner which you would have seen in shopping stores.

3. Sheetfed Scanner

In this scanner the document is inserted into the slot provided in the scanner. The main components of this scanner include the sheet-feeder, scanning module, and calibration sheet. The light does not move in this scanner. Instead the document moves though the scanner. It is suitable for scanning single page documents, not for thick objects like book, magazines, newspapers etc.

4. Drum Scanner

Drum scanner has a photomultiplier tube (PMT) to scan images. does not have a charge-coupled device like a flatbed scanner. The photomultiplier tube is extremely sensitive to light. The image is placed on a glass tube, and the light moves across the image, which produces a reflection of the image which is captured by the PMT and processed. These scanners have high resolution and are suitable for detailed scanning.

4. Joystick

A joystick is also a pointing input device like a mouse. It is made up of a stick with a spherical base. The base is fitted in a socket that allows free movement of the stick. The movement of stick controls the cursor or pointer on the screen.

5. Light pen

A Light Pen is a computer input device that looks like a pen. The tip of the light pen contains a light-sensitive detector that enables the ser to point to or select object on the display screen. Its light sesitive tip detects the object location and sends the corresponding signals to the CPU.

It is not compatible with LCD

screens, so it is not in use today. It also helps you draw on the screen if needed. The first light pen was invented around 1955 as a part of the Whirlwind project at the Massachusetts Institute of Technology(MIT)

6. Digitizer

Digitizer is a computer input device that has a flat surface and usually comes with a stylus. It enables the user to draw images and graphic using the stylus as we draw on papper with a pancil. The images or graphics drawn on the digitizer apear on the computer moniter or display screen. The software converts the touch inputs into lines and can also convert handwritter text to typewritten words.

7. Microphone

The Microphone is a computer input device that is used to input the sound. It recieves the sound vibrations and converts them into audio signals or sends to a recording medium. The audio signals are converted into digital data and stored in the computer.

8. Magnetic Ink Character Recognizer(MICR)

MICR computer input device is designed to read the text printed with magnetic ink. MICR is a character recognition technology that makes use of special magnetized ink which is sensitive to magnetic field. It is widely used in banks to process the cheques and other organizations where security is major concern. It can process three hundred cheques in a minute with hundred-percent accuracy. The details on the bottom of the cheque (MICR No.) are written with magnetic ink. A laser printer with MICR toner can be used to print the magnetic ink

9. Optical Character Reader (OCR)

OCR computer input device is designed to convert the scanned images of handwritten, typed or printed text into digital text. It is widely used in offices and libraries to convert documents and books into electronic files.

It processes and copies the physical form of a document using a scanner. After copying the documents, the OCR software converts the documents into a two-color (black and white), version called bitmap. Then it is analyzed for light and dark areas, where the dark areas are selected as characters, and the light area is identified as background. It is widely used to convert hard copy legal or historic documents into PDFs. The converted documents can be edited if required like we edit documents created in ms word.

10. Digital camera:

It is a digital device as it captures images and records videos digitally and then stores them on a memory card. It is provided with an image sensor chip to capture images, as opposed to film used by traditional cameras. Besides this, a camera that is connected to your computer can also be called a digital camera.

11. Paddle

It is a simple input device that is widely used in games. It is a wheel that is held by hand and looks like a volume knob on a stereo that is used to increase or decrease the volume. Paddle moves or controls cursor or any other objects in the game in a back-and-forth motion. It is widely used as an alternative to the joystick. Besides this, the term paddle also refers to many handheld devices designed to control a function in an electronic device, computer, etc.

12. Steering wheel

It is used as an input device in racing video games such as car racing games or in driving programs as virtual simulators to steer a vehicle. It works like the real steering wheel by allowing you to take a right or left turn. A steering wheel may be provided with acceleration and brake pedal devices and a mechanism for shifting gears. Thus, it makes racing games more adventurous and entertaining.

13. Gesture recognition devices

These devices take human gestures as input. There are many such devices that respond to gestures. For example, Kinect is one such device that observes the movement of a player's body and interprets these movements as inputs to video games. This feature is also available in certain tablets and smartphones where you can perform certain tasks such as taking pictures using finger gestures such as swiping, pinching, etc.

14. Light Gun

As the name suggests, it is a pointing input device that is designed to point at and shoot the targets on the screen in a video game, or arcade, etc. The light gun was used for the first time on the MIT Whirwind computer. When the gun is pointed at the target on the screen and the trigger is pulled, the screen goes blank for a fraction of a second. During this moment, the photodiode, which is present in the barrel, determines where the gun is pointed. For example, shooting ducks in a duck hunt game.

15. Touch pad

It is usually found in laptops as a substitute for the mouse. It allows you to move or control the cursor on the screen using your finger. Just like a mouse, it also has two buttons for right and left click. Using the touchpad, you can perform all the tasks that you do with a mouse, such as selecting an object on the screen, copy, paste, delete, open a file or folder, and more.

16. Remote

It is a hardware device

designed to control the functioning of a device, e.g., a TV remote that can be used to change channels, increase or decrease the volume, from a distance without leaving the seat. The first cordless TV remote was invented by Dr. Robert Adler of Zenith in 1956. The remote sends the electromagnetic waves to communicate with the device. These waves can be infrared rays, radio waves, etc.

17. Touch screen

It is the display screen of a device such as a smartphone, tablet, etc., that allows users to interact or provide inputs to the device by using their finger. Today, most of the electronic devices come with touchscreen as an alternative to a mouse for navigating a graphical user interface. For example, by touching, you can unlock your phone, open emails, open files, play videos, etc. Besides this, it is used in lots of devices such as Camera, Car GPS

, Fitness machine, etc.

The concept of the touch screen was first introduced and published by E.A. Johnson in 1965. The first touch screen was developed at the beginning of the 1970s by CERN engineers Frank Beck and Bent Stumpe.

18. VR

VR stands for virtual reality. It is an artificial or virtual environment which is generated by computers. A person can interact with virtual objects of this artificial environment using some input devices such as headsets, gloves, headphones, etc. For example, he or she can find himself or herself walking on a beach, watching a football match, walking in the sky, etc., without actually doing all this.

19. Webcam

Any camera which is connected to a computer is called a webcam. The in-built camera provided on a computer can also be considered a webcam. It is an input device as it can take pictures, and can be used to record videos if required. The pictures and videos are stored in the computer memory and can be displayed on the screen if required. Although it works almost the same as the digital camera, it is different from a digital camera, as it is designed to take compact digital photos that can be uploaded easily on the webpages and shared with others through the internet.

20. Biometric Devices

Biometrics refers to a process in which a person is identified through his or her biological features such as fingerprints, eye cornea, face structure, etc. It is done by using biometric devices, which can be of different types based on their scanning features and abilities