Glossary - Epson PowerLite S4 User Manual

Glossary

Glossary
The following is an explanation of some of the terms used in this guide which may be unfamiliar or which are not explained in the text of this guide itself. Further
information can be obtained by referring to other commercially available publications.
Aspect ratio The ratio between an image's length and its height. HDTV images have an aspect ratio of 16:9 and appear elongated. The aspect ratio for
standard images is 4:3.
Color Temp. The temperature of an object that is emitting light. If the color temperature is high, the colors take on a bluish tinge. If the color temperature
is lower, the colors take on a reddish tinge.
Component video Video signals which have the video brightness signals and color signals separated, in order to provide better image quality.
In high-definition TV (HDTV), it refers to images which consist of three independent signals: Y (luminance signal), and Pb and Pr (color
difference signals).
Composite video Video signals which have the video brightness signals and color signals mixed together. The type of signals commonly used by household
video equipment (NTSC, PAL and SECAM formats).
The carrier signal Y (luminance signal) and chroma (color) signal which are contained in the color bar are overlapped to form a single signal.
Contrast The relative brightness of the light and dark areas of an image can be increased or decreased in order to make text and graphics stand out
more clearly, or to make them appear softer.
Dolby Digital A sound format developed by Dolby Laboratories. Normal stereo is a 2-channel format which uses two speakers. Dolby Digital is a 6-channel
(5.1-channel) system which adds to this a center speaker, two rear speakers, and a sub-woofer.
HDTV An abbreviation for High-Definition Television. It refers to high-definition systems which satisfy the following conditions.
Vertical resolution of 750p or 1125i or greater (p = progressive, i =interlaced)
Screen aspect ratio of 16:9
Dolby Digital audio reception and playback (or output)
Interlaced A method of image scanning whereby the image data is divided into fine horizontal lines which are displayed in sequence starting from left to
right and then from the top to the bottom of the screen. The even-numbered lines and odd-numbered lines are displayed alternately.
Progressive A method of image scanning whereby the image data from a single image is scanned sequentially from top to bottom to create a single
image.
Refresh rate The light-emitting element of a display maintains the same luminosity and color for an extremely short time. Because of this, the image must
be scanned many times per second in order to refresh the light-emitting element. The number of refresh operations per second is called the
"refresh rate", and is expressed in hertz (Hz).
SDTV An abbreviation for Standard Definition Television. It refers to standard television systems which do not satisfy the conditions for High-
Definition Television.
Security lock A commercially available cable that can be attached to the projector to prevent theft. This projector is compatible with the Microsaver
Security System manufactured by Kensington.
Squeeze mode In this mode, wide-screen images in 16:9 mode are compressed in the horizontal direction so that they are stored on the recording medium
as 4:3 images.
When these images are played back by the projector in squeeze mode, they are restored to their original 16:9 format.
sRGB An international standard for color intervals that was formulated so that colors which are reproduced by video equipment can be handled
easily by computer operating systems (OS) and the Internet. If the connected source has an sRGB mode, set both the projector and the
connected signal source to sRGB.
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