Input Devices

Input Devices

Input devices are responsible for taking input and converting it into computer understandable form (binary code 0 for off, 1 for on). Some examples of input devices are- keyboard, mouse, magnetic ink character reader(MICR), Optical Mark Reader(OMR), Optical character reader(OCR), Joystick, etc.

Types of Input devices

Keyboard- Keyboard is an important data entry device, which is a typewriter-like device. It contains a matrix of switches and a keyboard controller. When we press a key its switch gets pressed and when we release key its switch gets released. by pressing and releasing of switches keyboard controller generates a scan code and sent it to the PC.

Mouse- The mouse is a pointing device that fits under the palm of a hand. When a mouse moves on a flat surface the cursor on the screen also moves in the direction of mouse movement. A mouse generally has two or three buttons and it may or may not have a wheel. With its buttons and wheel, a mouse can perform any of these operations such as- point, click, double click, drag, etc.

Light-Pen- A light Pen consists of a photocell mounted in a pen-shaped tube. When the pen is brought in front of a picture element of the screen, it senses light coming from a limited field of view. Clicking can be performed by the light pen by pressing the pen on the screen. The light pen s also used to draw images on the screen.

Touch Screen- Touch screen is a type of display screen, that has a touch-sensitive transparent panel covering the screen is known as touch screen. Instead of using any pointing device such as a mouse or light pen we can use our finger to point directly to objects on the screen

Graphics Tablet- A graphical tablet consist of an electronic surface and a pen which is also called a puck is similar to a mouse. Graphic tablet detect movement of the pen and translate the movement into digital signals that it sends to the computer

Joystick- Joystick is a device that lets the user move an object on the screen. Joysticks are used for playing games on the computer. By using joystick players can control the movement of an object. It is much easier as compared to pressing keys on the keyboard.

Microphone- By using Microphone we can send sound input to the computer. We can speak words or input a sound through a mic and the sound card translate the electrical signals from the microphone into a digitized form.

Magnetic Ink Character Reader(MICR)- Magnetic ink character that is printed using a special ink called magnetic Ink, that contains iron oxide. MICR reads these characters by magnetizing the ink and by examining the shape of the character. MICR is mainly used by banks for reading a cheque, for instance the branch code, account number, and cheque number printed at the bottom using magnetic ink.

Scanner- A scanner is a device like a photocopier which creates an electronic form of a printed image. There we have three types of scanners-

Handheld scanner- These are very small in size and can be held in a hand.

Flatbed scanners- These are larger and more expensive and used to create high-quality images. These scanners have a flat surface on which the printed image can be scanned.

Drum scanner- These are medium size scanners with a rolling drum

Optical Character Reader(OCR)- OCR is used to read characters of special type font printed on conventional paper with conventional ink. These days OCRs are capable of reading/identifying handwritten text also.

Optical mark reader (OMR)- By using OMR we can read marks. OMR translates the marks in electrical pulses which are transmitted on the computer, OMR is best suited for objective type answer checking such as to read questionnaires, multiple choice examination paper etc.

Smart card reader- A smart card is a physical electronic authorization card and has a magnetic stripe and a microprocessor that retains certain security and personal data in its memory at all times. The special reader machine that can read the information on the smart card is called a smart card reader. Smart cards have a variety of applications including banking, medical records, security, and many more.

Bar-code reader- A bar-code is a pattern of printed bars on various types of products. A bar-code reader emits a beam of light to recognizes special bars at both ends of the image. Once the bar code is identified, the bar pattern is converted into a numeric code that can be processed later in any manner.

Bio-metric sensor- Bio-metric technology includes dynamic signature verification, retina pattern, face shape, DNA and fingerprints identification, etc. and a Bio-metric sensor machine is used to read these signals.

Digital camera (Digicam)- A camera that can store images digitally is called a digital camera. Once a picture has been taken it can be downloaded to a system and then manipulated with graphic programs such as Photoshop, CorelDraw, etc. and then printed.

Web camera (Webcam)- Web camera is a camera that is connected to a computer either directly or wirelessly. A webcam is used for video conferencing or video chat.