Input Devices

Devices with the help of which users can enter data or instructions into are called as input devices. They are many types of input devices. But, different input devices are capable of entering different types of data. For example, keyboard is used to enter text data, scanners are used to enter image data, etc. The following are various input devices available.

 Keyboard  Mouse  Track ball  Track pad  Touch screen  Light  Magnetic character recognition (MICR)  Scanners  Optical mark reader  Bar code reader  Micro phone

• Keyboard: Keyboard is most popular . It is very much like a standard typewriter. It is used to enter text into the computer. The layout of a keyboard resembles that of a type writer with few additional keys. Keyboard contains alphanumeric keys, arrow keys, numeric keypad, functional keys and some special keys like ‘enter’, ‘escape’, etc. Some specific functions are attached to each functional key depending on the software you are using. For example F1 key is used to get help in almost all software’s.

S.No Keys & Description

1 Typing Keys

These keys include the letter 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 consists of a 2 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 3 at the top of the keyboard. Each function key has a unique meaning and is used for some specific purpose.

Control keys

These keys provide cursor and screen control. It includes four directional arrow 4 keys. Control keys also include Home, End, Insert, Delete, Page Up, Page Down, Control(Ctrl), Alternate(Alt), Escape(Esc).

Special Purpose Keys

5 Keyboard also contains some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab, and Print Screen.

• Mouse: Mouse is a popular . We cannot enter text with the help of mouse. Instead we can move the cursor on the screen with the help of mouse and thus can select something on the screen. We can place the mouse on a table or on some flat surface and if we move the mouse left or right or in any direction, the cursor on the screen also moves accordingly. Mouse in general has two buttons, called left button and right button and a wheel in the center.

• Track ball: is also a pointing device. A trackball is an input device used to enter motion data into or other electronic devices. It is similar to mouse and serves the same purpose as a mouse, but is designed with a moveable ball on the top, which can be rolled in any direction. It is mostly used in laptops and notebooks.

• Track pad: A track pad is a device for pointing (controlling input positioning) on a computer display screen. It is an alternative to the mouse. Originally incorporated in laptop computers, track pads are also being made for use with desktop computers. If we move our finger on the track pad , accordingly cursor will move on the screen.

• : Joystick is also a pointing device, which is used to move the cursor position on a monitor screen. It resembles a gear rod of a car. It is a stick having a spherical ball at its both lower and upper ends. The lower spherical ball moves in a socket. The joystick can be moved in all four directions.

• The function of the joystick is similar to that of a mouse. It is mainly used in Computer Aided Designing (CAD) and playing computer games.

• Touch Screen: It allows the user to operate and make selections by simply touching the display screen. Touch screen is a display screen that is sensitive to the touch of a finger or . Widely used for smart phones, near ATM machines, retail point-of- sale terminals, car navigation systems, medical monitors, industrial control panels, etc.

• Light Pen: Light pen is an input device that utilizes a light-sensitive detector. It is used to select objects on a display screen or to draw pictures on the screen.

• Magnetic ink character recognition (MICR): MICR can identify characters printed with a special ink that contains particles of magnetic material. This device particularly finds applications in banking industry.

• • Optical mark recognition (OMR): Optical mark recognition, also called mark sense reader is a technology where an OMR device senses the presence or absence of a mark, such as mark. OMR is widely used in competitive exams.

• Bar code reader: Bar-code readers are photoelectric scanners that read the bar codes or vertical zebra strips marks, printed on product containers. These devices are generally used in super markets, bookshops etc.

• Scanner: Scanner is an input device that can copy an image on to the screen. If a photo or any document is placed on the scanner, the photocopy of the document or the photo will be seen on the computer screen. A scanner works by digitizing an image. We are having mainly three types of scanners. They are:-

o Flat bed Scanner o Sheet fed Scanner. o Hand held scanner.

Flat bed scanner: Here, in this scanner, photo or any paper is placed on the top of the scanner after flipping the cover, and then the image will be copied on to the screen.

Sheet fed Scanner: This scanner looks like a roller. Any photo or paper is to be fed from one side of the roller, so that the image will be copied into the computer. When we compare flat bed scanner and sheet fed scanner, flat bed scanner performs well because if we feed the photo wrongly(tilted) in sheet fed scanner, you will get tilted photo on the screen.

Hand held scanner: Here, photo is placed on some table or on a flat surface and then by holding the hand held scanner in hand, we have to manually move on the photo.

Microphone is an input device to input sound that is then stored in a digital form.

The microphone is used for various applications such as adding sound to a multimedia presentation or for mixing music.