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2-4. Circuit Description
PR-200 board
The R, G and B video signals from the MX-59 board are
input to the input amplifier and are then passed through the
knee and black gamma circuits. After the gamma correc-
tion is performed by the gamma circuit, the video signals
are then adjusted in level and are mixed with the knee
aperture signal. The resultant signals are output via the
output amplifier.
The PR-200 board is provided with the diagnosis circuit,
knee saturation circuit, super skin-knee correction circuit,
and detection circuit for auto-knee correction. The adjust-
ment data for the PR-200 board is stored in the EEPROM
on the board.
DL-65 board
The DL-65 board generates 1H-delayed R/G/B signals and
2H-delayed G signal, which are needed to create detail
signals. The R/G/B video signals are analog-to-digital
converted and then enter the FIFO memory to create those
delayed signals. The delayed signals are digital-to-analog
converted again and are output to the IE-44 board together
with a 0H-delayed signal.
The DL-65 board has the diagnosis circuit, too.
IE-44 board
IE-44 board generates the H/V detail signals. The detail
signals are controlled in detail balance, detail level and
frequency, and are crispened. The resultant signals are
mixed with the main line signal.
In addition, IE-44 board has the color-bar signal generator
and diagnosis circuit. The main line signal can be switched
over to the color-bar signal according to use.
The main line signal is passed through the white clipping
circuit and blanking circuit where the SYNC is added to
the signal.
The adjustment data for the IE-44 board is stored in the
EEPROM on the board.
2-4 (E)
IF-569 board
IF-569 board consists of a microcomputer for system
control and its peripheral circuits. The main program is
written in the EPROM on the board. And the camera
control data is stored in the SRAM, so the data is kept even
if powered off owing to the backup circuit. Moreover, the
IF-569 board is provided with the interface circuit with the
lens and auto-iris control circuit.
In addition, the IF-569 board has an interface circuit
supporting the new command system to communicate with
the camera adaptor. The interface circuit is used to inter-
face with an 1.5-inch viewfinder through the 2-wired serial
bus.
HDC-750A
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