Monitors And Sound Systems

Monitors And Sound Systems
•Monitors

• PC Projectors

• Sound Systems

Monitors
Monitors – Categories of Monitors

monitors are categorized by the technology they use:

•Cathode ray tube (CRT) monitors

•Flat-panel displays

And by the way they display colors:

•Monochrome – One color on a black background

•Grayscale – Shades of gray on a white or of-white
background

•Color – From 16 to 16 milion unique colors

Monitors – CRT Monitors

•In CRT monitors, electrons are fired at phosphor
dots on the screen.

•The dots are grouped into pixels, which glow when
struck by electrons.

•In color CRTs, each pixel contains a red, green, and
blue dot. These glowat varying intensities to
produce color images.

Monitors – Flat-Panel Monitors

•Most flat-panel monitors use liquid crystal display
(LCD) technology.

•Pasive matrix LCD uses a transistor for each row
and column of pixels.

•Active matrix LCD uses a transistor for each pixel on
the screen.

•Thin-film transistor displays use multiple
transistors for each pixel.

Monitors – Comparing Monitors

When comparing monitors, consider four features:

• Size

• Resolution

• Refresh rate

• Dot pitch

Comparing Monitors – Size

•A monitor’s size is the diagonal measurement of its
face, in inches.

•For years, 15″ monitors (13″viewing area) were
standard.

•Today, 17″ monitors (15″ viewing area) are common.

•Larger monitors are available, but can be expensive.

Comparing Monitors – Resolution

•Resolution is the number of pixels on the screen,
expressed as a matrix (such as 600×800).

•A 17″ monitor ofers resolutions from 640×480 up to
1280×1024.

•The Video Graphics Array (VGA) standard is
640×480. Super VGA (SVGA) monitors provide
resolutions of 800×600, 1024×768 or higher.

Comparing Monitors – Refresh Rate

•Refresh rate is the number of times each second that
the electron guns scan the screen’s pixels.

•Refresh rate is measured in Hertz (Hz), or cycles per
second.

•Look for a refresh rate of 72 Hz or higher. A slower
rate may cause eyestrain.

Comparing Monitors – Dot Pitch

•Dot pitch is the distance between the phosphor dots
that make up a single pixel.

•In color monitors, three dots (red, green, and blue)
comprise each pixel.

•Look for a dot pitch no greater than .28 milimeter.

Monitors – Video Controlers

• The video controler is an interface between the
monitor and the CPU.

• The video controler determines many aspects of a
monitor’s performance, such as resolution or the
number of colors displayed.

• The video controler contains its own on-board
processor and memory, caled video RAM (VRAM).

PC Projectors

•A PC projector connects to a PC and is used to
project images on a large screen.

•Many PC projectors provide the same resolutions and
color levels as high-quality monitors.

•Digital light processing (DLP) projectors use a
microchip containing tiny mirrors to produce very
sharp, bright images.

Sound Systems

• Multimedia PCs come with a sound card, speakers,
and a CD-ROM or DVD drive.

• A sound card translates digital signals into analog
ones that drive the speakers.

• With the right software, you can use your PC to edit
sounds and create special sound efects.

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