Input Devices

Input Devices The input input is used for entering data and program into the computer system for processing. It is a medium of communication...

Input Devices

The input input is used for entering data and program into the computer system for processing. It is a medium of communication between the user and the computer.

Fig: Input Devices

Eg: Keyboard, Mouse, Trackball, Track Pad, Joystick, Light pen, Touch screen, Scanner, Bar code reader, Optical character reader (OCR), Magnetic Ink Character Reader (MICR), Microphone etc

1. Keyboard

The keyboard is the most common means of hardware by which user will input the data. It looks like an electronic typewriter keyboard but contains keys for specific purposes. It is quite similar to the keyboard of the typewriter (QWERTY) but contains some additional keys.

When the user pressed a key, a tiny chip called the keyboard controller notes that a key has been pressed. The keyboard controller places a code into part of its memory, called the keyboard buffer, to indicate which key was pressed.

Fig: Keyboard

2. Mouse

Mouse is a small hand held pointing and clicking input device used to control the position of the cursor on the screen. It is a small plastic box with two or three buttons on the top.

Types of Mic

• Mechanical mouse
• Opto-mechanical mouse
• Optical mouse
  

Fig: Mouse

3. Trackball

Trackball is another form of pointing device. It is a variant on the mouse. It has a movable ball on top of a stationary device that is rotated with the fingers or palm of the hand.

Fig: Trackball

4. Touch Pad Kiosk

It is one of the latest pointing devices. It looks like the small grey window, about two inches wide. The user slides his finger tip across the window to move the cursor on the screen. When the window is tapped, it works as the clicking of mouse button. It is used in latest laptops.

Fig: Touch Pad Kiosk

5. Joystick

A joystick is a pointing device that consists of a vertical handle like a gearshift lever mounted on a base with one or two buttons. It is used principally in video games and in some computer-aided design systems. As the handle is moved around, the movement is translated into binary signals with the help of electronic contacts in its base.

Fig: Joystick

6. Light Pen

The light pen is a light-sensitive stylus, or pen-like device, connected by a wire to the computer terminal. The user brings the pen to a desired point on the display screen and presses the pen button which detects the light emitted from the screen and generates electric pulses, which are transmitted to a processor that identifies the particular pixel. 

Fig: Light Pen

7. Touch Screen

A touch screen is a video display screen that has been sensitized to receive input from the touch of a finger or some pointed object. It is a screen with touch sensitive points or program icons. When a specific point is touched by finger tips, related program is activated. It is a modern and advanced technology applied in laptops, cameras, mobile phones and lot more modern electronic devices.

Fig: Touch Screen

8. Digitizing Tablet

A digitizing tablet consists a tablet connected by a wire to a stylus or puck. A stylus is a pen-like device with which the user sketches an image. A digitizing tablet and stylus allows shading and many other effects similar to those artists with pencil, pen or charcoal.

Fig: Digitizing Tablet

9. Digital Camera

Digital still and video camera are used to capture picture and video which is in the digitized form and can be stored in computers. It can take the photo and load them directly from the camera digitally to a main storage or secondary storage device.

Fig: Digital Camera

10. Scanner

The scanner is an input device which is used to enter text, images, and graphs printed on paper directly into the computer. It provides faster and more accurate data entry. The compact desktop scanner is popular, due to its low cost and easy to use with PC.

Fig: Scanner

11. Bar Code Reader (BCR)

Bar code reader is a photo-electric scanner that reads bar codes. Bar code is an identification code printed in the form of light and dark bars with coded spacing and thickness which contains identification of an item such as price, quality, manufacturer.

Fig: Bar Code Reader

12. Optical Character Reader (OCR)

The OCR reads printed characters directly, converts them into appropriate codes and stores them in a computer. When light source is passed over a document, written or typed character reflects less light than the background area. Thus, the shape of the character is determined.

Fig: Optical Character Reader

13. Optical Mark Reader (OMR)

The OMR is a device that reads pencil marks or shades and converts them into computer usable form. It is mainly used to read answer sheets of multiple choice questions and survey form, Graduate Record Examination (GRE) etc.

Fig: Optical Mark Reader

14. Magnetic Ink Character Reader (MICR)

The MICR is an input device, which reads the characters printed using magnetic ink. Magnetic ink is a special type of ink containing iron-oxide particles, which is used to write characters. The MICR is mostly used in the bank for processing cheque.

Fig: Magnetic Ink Character Reader

15. Smart Card

A smart card looks like a credit card but contains a microprocessor and memory chip. It can be used for using public telephone, bank card, as well as for carrying their medical histories on them.

Fig: Smart Card

16. Microphone

The microphone is an input device used for recording voice or sound. It is widely used for the sound input to the computer for voice mail, videoconferencing, video chat.

Fig: Microphone

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