An output device is any peripheral device that converts machine-readable information into people-readable form such as a monitor, printer, plotter and voice output device.

A computer display is also called a display screen or video display terminal (VDT). A monitor is a screen used to display the output.

• Screen resolution: A 1024x768 resolution means that it has 1024 dots in a line and 768 lines.

 

• Interlaced/Non-interlaced: An interlaced technique refreshes the lines of the screen by exposing all odd lines first then all even lines next.

There are two forms of display: cathode-ray tubes (CRTs) and flat-panel display.

 

Cathode Ray Tubes (CRT)

 

A CRT is a vacuum tube used as a display screen for a computer output device. Although the CRT means only a tube, it usually refers to all monitors.

Monochrome Monitors

A monochrome monitor has two colors, one for foreground and the other for background.

Color Monitors

A color monitor is a display peripheral that displays more than two colors. Color monitors have been developed through the following paths.

• CGA:
• EGA:
• VGA:
• Super VGA:

Flat Panel Displays

 

Portable computers such as a lap top use flat panel displays, because they are more compact and consume less power than CRTs.

Liquid-Crystal Displays (LCDs)

A display technology that creates characters by means of reflected light and is commonly used in digital watches and laptop computers.

• Backlit LCDs:
• Active Matrix LCDs:

Printers

A printer is an output device that produces a hard copy of data. The resolution of printer output is expressed as DPI. Printers can be classified into different types in several ways.

• Serial Printers:
• Line Printers:
• Page Printers:

• Impact Printers:
• Nonimpact Printers:
• Bit-Mapped Printers:
• Character-based Printers:

   

Microcomputers use five kinds of printers. They are daisy wheel printers, chain printers, dot-matrix printers, ink-jet printers, and laser printers.

Daisy-Wheel Printer

Chain Printer

Dot-Matrix Printer

Ink-Jet Printer

Plotters

A plotter is a special-purpose output device that draws images with ink pens.

• Drum Plotter:

 

• Flatbed Plotter:

   

This device produces a human speech like sound, but actually is prerecorded vocalized sounds.

Modem

Another form of the output device is a modem. A modem is short for "Modulator-Demodulator." Modulation is the process of converting from digital to analog.