JVC 250 - Manual (Page 186)

Glossary
Model 250 Service Manual A-1
Glossary of Terms
Amorphous Without definite form; not crystallized.
Arc Lamp The high intensity light source in the Model 250
projector. The Xenon Arc Lamp operates at high
temperatures (160° to 200°) and produces
dangerously intensive light with hazardous levels
of ultraviolet and infrared radiation.
Aspect Ratio The ratio of the picture width to picture height.
The standard U.S. television aspect ratio is four
units wide to three units high (4:3).
Bandwidth Bandwidth is the difference between the lowest
and highest frequencies transmitted or received. In
digital formats it is measured in bits per second
and in communications, it is measured in Hertz.
Wider bandwidth provides more information or
picture detail capability.
Chrominance Abbreviated as “C”. The portion of the YPbPr
and S-image signal that contains the color
information signal.
Cold Mirror Mirror that absorbs infrared light so that its
reflection contains only “cold light” or light that
does not transmit appreciable heat. Because of
this absorption of infrared heat radiation, “cold
mirrors” get quite hot.
Cross-member Assembly Assembly attached to the main chassis that
crosses over the top of the midsection of the
projector. Used to mount the front and rear
covers.
CRT (Cathode Ray Tube) The Cathode Ray Tube is used as a display screen
in televisions and computer monitors. Commonly
referred to as the picture tube. The Model 250
projector uses three CRTs.
Dichroic Mirrors The white light of the xenon arc lamp is separated
into red, green and blue by means of dichroic
beamsplitters that reflect only one color and pass
all others.