Input Devices and Their Functions

Trackball

• A trackball is an input device that allows users to control the cursor or icon on a computer screen.
• Users control the trackball by rotating a pointing ball with their thumb, fingers, or palm.
• Trackballs resemble an inverted mouse.

Joystick

• A joystick is an input device that allows users to control the movement of the cursor or pointer on a computer screen.
• Joysticks are commonly used for playing video games.

Scanner

• A scanner is a device that optically scans images, text, handwriting, or objects and converts them into digital images.
• Scanners come in various types.

Optical Character Recognition (OCR)

• OCR is a process that converts text images into machine-readable text format.
• OCR technology allows users to easily edit scanned documents.

Optical Bar Code Reader (OBCR)

• OBCRs are input devices that read bar codes from products and transmit information to a computer.

Optical Mark Recognition (OMR)

• OMR is an electronic method for collecting data by identifying markings on a document.
• OMR is commonly used to grade multiple-choice tests and surveys.

Magnetic Ink Character Recognition (MICR)

• MICR is a character recognition technology that uses special magnetized ink.
• MICR is widely used in banking for processing checks.

Output Devices

• Output devices produce the results of processed input.

Printer

• A printer is a device that accepts input from a computer and outputs the information to paper.
• Printer quality is typically measured in dots per inch (DPI).

Impact Printers

• Impact printers use hammers, pins, or wheels to strike an inked ribbon and print onto paper.
• Impact printers generally have lower print quality than non-impact printers.
• Examples of impact printers include dot-matrix printers, daisy-wheel printers, and line printers.

Non-Impact Printers

• Non-impact printers use ink sprays, lasers, heat, and pressure to print.
• Non-impact printers generally produce higher quality prints than impact printers.
• Examples of non-impact printers include inkjet printers, laser printers, thermal printers, and 3D printers.

Monitors

• A computer monitor is an output device that displays information in pictorial or textual format.
• Also called a Visual Display Unit (VDU), the monitor displays the computer's user interface and open programs.

Technologies Used in Monitors

• Cathode Ray Tube (CRT)
• Liquid Crystal Display (LCD)
• Light-Emitting Diode (LED)
• Thin Film Transistor (TFT)

Plotter

• Plotters are used to print graphical output on paper.
• Plotters are capable of producing graphs, drawings, charts, maps, and other large graphics.
• There are two types of plotters: drum plotters and flatbed plotters.

Both Input and Output Devices

• Touchscreen
• Network Interface Card (NIC)
• Headset (Headphone + Microphone)
• Modem (Modulation + Demodulation)