Dell Projector 1220 User Manual page 53

average light output of the black rectangles to determine the ANSI contrast
ratio.
Full On/Off contrast is always a larger number than ANSI contrast for the
same projector.
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, 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.
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.
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 53