Output

Thomas W. Davis

What is Output?

Output it data that has been processed into a useful form

Output includes:MonitorsPrintersSpeakersEtc.

Basic Categories

Text

Graphics

Audio

Video

Display Devices

Display device: output device that visually conveys text, graphics, and video information Information is referred to as a soft copy

Consist of a screen and the components that produce the information on the screen

Monitor

Plastic or metal case that houses a display device as a separate peripheral

Most mobile computers and devices integrate the display and other components into the same physical case

Display may be color or monochrome

CRT Monitors

A desktop monitor that is similar to a standard television because it contains a cathode-tube

A cathode-ray tube (CRT) is a large, sealed glass tube

How the Display Works

The screen is made of dots of phosphor materialEach dot is made of red, green, and blueThree dots combine to form a pixel

An electron beam moves back and forth across the back of the screen causing the dots to glow, producing an image

Monitor Sizes

You measure monitor size diagonally from top left corner to bottom right cornerThis is divided into viewable size and

actual size

Determining the size of the monitor to purchase depends on the intended use

CRT Monitor Ergonomics

Features that include: tilt-and-swivel base, brightness, contrast, positioning, height, and width controls

ENERGY STAR programEncourages manufacturers to create

energy efficient devices that use little energy when not in use

Quality of a CRT Monitor

Depends on the resolutionDescribes the sharpness and clearness of

an imageMost monitors support a wide range or

resolutions up to 1600 x 1200, with 800 x 600 the normal

Also depends on dot pitch and refresh rate

Video Cards and CRT Monitors

Video card: converts digital output from the computer into an analog video signal and sends the signal through the cable to the monitor, which displays output on the screen

Color Depth

The number of bits a video card uses to store information about each pixelThe greater the number of bits the better

the image

Flat-Panel Displays

Flat panel display is a display with a shallow depth that does not use CRT technology

Includes monitors, LCD displays, gas plasma displays and HDTV

Flat-Panel Monitors

Also called an LCD monitor, is a desktop monitor that uses a liquid crystal display rather than a cathode-tube to produce images

Advantages to a Flat-Screen

Take up less desk space, called footprint

Uses one-third the power of a CRT monitor

Produces less heat

Does not produce radiation

LCD Technology

Liquid crystal display (LCD) uses a liquid compound to present information on a screenProduce color using either passive-matrix or active-matrix technologyLCD quality is measured in the same manner as CRT display quality is measured

Gas Plasma Displays

A display that uses gas plasma technology, which substitutes a layer of gas for the liquid crystal material in a flat panel monitor

When voltage is applied, the gas releases UV light causing pixels on the screen to glow

Televisions and HDTV Displays

Digital televisions have two major advantagesDigital signals produce a higher-quality

pictureMany programs can be broadcast on a

single digital channel

HDTV: is the most advanced from of digital television

Printers

A printer is an output device that produces text and graphics on a physical medium

Produce hard copies of data

Impact Printers

Impact Printer: form characters and graphics by striking a mechanism against an inked ribbon that physically contacts the paper

Types: DOT-MARTIX Printer Line Printers

Nonimpact Printers

Nonimpact printers: forms characters and graphics on a piece of paper without actually touching the paper

Types: Ink-Jet Photo Printers Laser Printers Thermal Printers Portable Printers

Speakers and Headsets

Audio output device: a component of a computer that produces music, speech or other sounds

Faxes Machines and Fax Modems

Fax machine: short for facsimile machine, is a device that transmits and receives documents over telephone lines.

Fax modem: allows the user to send and receive electronic documents and faxes.

Multifunction Perpheral

A single device that looks like a copy machine but provides the functionality of a printer, scanner, copy machine, and a fax machine

Data Projectors

A device that takes the image from computer screen and projects it onto a larger screen

LCD Projector

Digital Light Processing Projector