Epson S4 Glossary, Glossary

Glossary

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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.