Dell 7700HD Projector User Manual

Page 117

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dB — decibel — A unit used to express relative difference in power or intensity,

usually between two acoustic or electric signals, equal to ten times the common

logarithm of the ratio of the two levels.
Diagonal Screen — A method of measuring the size of a screen or a projected

image. It measures from one corner to the opposite corner. A 9 ft high and 12 ft

wide, screen has a diagonal of 15 ft. This document assumes that the diagonal

dimensions are for the traditional 4:3 ratio of a computer image as per the example

above.
DHCP — Dynamic Host Configuration Protocol — A network protocol that

enables a server to automatically assign a TCP/IP address to a device.
DLP

®

— Digital Light Processing™ — Reflective display technology developed by

Texas Instruments, using small manipulated mirrors. Light passing through a color

filter is sent to the DLP mirrors which arrange the RGB colors into a picture

projected onto screen, also known as DMD.
DMD — Digital Micro-Mirror Device — Each DMD consists of thousands of

tilting, microscopic aluminum alloy mirrors mounted on a hidden yoke.
DNS — Domain Name System — An Internet service that translates domain

names into IP addresses.
Focal Length — The distance from the surface of a lens to its focal point.
Frequency — It is the rate of repetition in cycles per seconds of electrical signals.

Measured in Hz (Hertz).
HDCP — High-Bandwidth Digital-Content Protection — A specification

developed by Intel™ Corporation to protect digital entertainment across digital

interface, such as DVI, HDMI.
HDMI — High-Definition Multimedia Interface — HDMI carries both

uncompressed high definition video along with digital audio and device control

data in a single connector.
Hz (Hertz) — Unit of frequency.
IEEE802.11 — A set of standards for wireless local are network (WLAN)

communication. 802.11b/g/n uses the 2.4 GHz band.
Keystone Correction — Device that will correct an image of the distortion

(usually a wide-top narrow-bottom effect) of a projected image caused by

improper projector to screen angle.
Maximum Distance — The distance from a screen the projector can be to cast an

image that is usable (bright enough) in a fully darkened room.
Maximum Image Size — The largest image a projector can throw in a darkened

room. This is usually limited by focal range of the optics.

Glossary

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