2. FEATURES
2-1CONTRASTENHANCEMENT CIRCUIT
Acontrast enhancement circuit, providing for the independent amplifica-
tion of overall video gain and black level(offset), allows image contrast
to be dramatically increased over a very wide range. This feature makes
possible the visualization of structures undetectable visually or photo-
graphically.
2-2AUTOMATIC GAINCONTROL CIRCUIT
This circuit detects the intensity of the incident light, automatically
adjusts the amp gain, and keeps a constant video signal level.
The correction range against the incident light is about 8:1.
(It corresponds to the iris at 3 levels.)
2-3 SIT PROTECTION CIRCUIT
When using a SIT tube as for a camera head, this circuit protects the SIT
tube fro■the excessive incident light.
When the quantity of light, is 1.3 times as much as the normal that, is
input, this circuit works.
2-4 TIMINGCONTROL BY CRYSTAL OSCILLATION
All control signals, as well as deflection frequency, are controlled by
crystal oscillation. This results in very high precision in the scanning
and synchronization signals ensuring a consistently high quality image.
2-5 LEVEL INDICATOR
Avideo level indicator circuit accurately monitors input intensity to
the imaging tube by way of two LED's. This feature allows for the rapid
determination of the ideal illumination level required to produce the
highest quality image.
2-6 TUBE PROTECTION CIRCUIT
Aprotection circuit has been provided to prevent burn-in of the imaging
tube should the horizontal or vertical synchronization signals be lost.
2-7 WHITE CLIPPER
This circuit clops the video signal when it exceeds 1.2V thereby prevent-
ing the TV monitor fro■losing synchronization.
—2—
