Glossary
Model 330, 340SC, and 370SC Service Manual
Gray Scale
Test pattern of black-to-white gradation bars. The more levels
of gray scale that can be handled, the more realistic an image
can be displayed, especially a photograph that has been
scanned into the computer.
HDTV
(High Definition Television) Has approximately twice the
horizontal and vertical emitted resolution of standard NTSC.
HDTV systems are wide aspect ratio systems.
Hertz (Hz)
The standard unit of frequency. One Hz is equal to one cycle
per second. A Kilohertz (KHz) is 1,000 cycles per second and
a Megahertz (MHz) is equal to 1,000,000 cycles per second.
H-Grid
Test Pattern 8 with rows of white H's on screen, used as a
focusing aid.
Horizontal Scan
Frequency (H-Freq)
The rate at which horizontal lines are made to
scan on a CRT. This is controlled by horizontal sync from the
signal source.
Horizontal Scan
Reversal Jumper
Reverses the image projection for front or rear
projection. Located on the Horizontal Deflection Board.
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.
IDTV
(Improved Definition Television) Improvements that modify
NTSC standards. Improvements may be at the source or the
receiver.
Image Light Amplifier
ILA
®
A device that uses low-intensity images to phase-modulate a
high-intensity light through a liquid crystal layer. It is the key
component in producing very bright, high resolution images
from Hughes-JVC large-screen projectors.
Import Channel
Imports setup data from computer to projector. Store setup
data in computer and import during setup. Useful when
servicing the projector. See Export Channel Data and refer to
Appendix 1 for more details.
Infrared Repeater
Used with rear projection setups. Conveys infrared signals to
HJT Series 300 Projector, since I/R remote control signals
cannot reach I/R windows on the projector.