JVC 250 Field, Frame, Horizontal Scan, Reversal Jumper, Horizontal Size Coils, Hot Spot, Ignitor

Glossary

Field	One half of a complete video frame. Odd lines in
	one field and even lines in another make up one
	frame.
Frame	One complete TV picture or screen of
	information. It is composed of two fields and has
	a total of 525 scanning lines in NTSC
	transmission.
Horizontal Scan	Reverses the image projection for front or rear
Reversal Jumper	projection. Located on the Horizontal Deflection
	Board and Scan Reversal PCB.
Horizontal Size Coils	Adjustment coils on the Scan Reversal Board.
	Used to adjust the horizontal size (width).
Hot Spot	The Arc Lamp’s brightest area on the screen.
	Used to align and focus the Arc Lamp.
Hue	Also referred to as tint. A specific color such a
	blue, pink or aqua. Hue or tint control on a
	display device adjusts red/green balance.
Ignitor	Provides a momentary high voltage to excite the
	gases in the Xenon Arc Lamp to ignite.
Image Light Amplifier	A device that uses low-intensity images to phase
ILA®	modulate a high-intensity light through a liquid
	crystal layer. It is a key component in
	producing very bright, high resolution images
	from Hughes-JVC large-screen projectors.
Image Mirror	Also referred to as a “Steering Mirror”. It directs
	the blue and red images toward the Combining
	Prism.
Interlacing	The technique that refreshes a display screen by
	alternately displaying all the odd lines (field one)
	and then all the even lines (field two) of one
	frame.
I/R Detector	The Model 250 Projector has two I/R Detectors,
	one in front, one in back. These windows receive
	projector control signals from the I/R Remote
	Control.
Laser Power Supply	Provides boost voltage through a spark gap to the
	Ignitor.

A-2 Model 250 Service Manual