Dell 1220 User Manual page 52

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.
— Digital Light Processing™ — Reflective display technology
®
DLP
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.
Minimum Distance — The closest position that a projector can focus an
image onto a screen.
NTSC — National Television Standards Committee. North American
standard for video and broadcasting, with a video format of 525 lines at 30
frames per second.
PAL — Phase Alternating Line. A European broadcast standard for video
and broadcasting, with a video format of 625 lines at 25 frames per second.
Reverse Image — Feature that allows you to flip the image horizontally.
When used in a normal forward projection environment text, graphics, etc.
are backwards. Reverse image is used for rear projection.
RGB — Red, Green, Blue — typically used to describe a monitor that
52 Glossary