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2-4. Circuit Description
BI-132 board
The BI-132 board supplies the DC bias required for the
CCD. The CCD output is sent through a buffer to the NR-
66 board. The BI-132 board mounts horizontal clock
drivers for the CCD and a reset gate driver.
CN-1674 board
The CN-1674 board is the relay board that supplies each
CCD driving pulse generated on the DR-376 board to the
BI-132 board. The CN-1674 board also generates the
voltage used for the horizontal clock drivers for the CCD.
DR-376 board
The DR-376 board mounts the vertical clock drivers for
CCD driving, drivers for a shutter pulse and V/H driver.
And the DR-376 board generates the V-sub voltage proper
to the CCD and then supplies it to the CCD.
The voltage produced using a DC/DC converter is sent
through this board to each board.
TG-209 board
The TG-209 board generates clock pulses and PLL-locks
them with the VCO on the SG-226 board (of the camera
adaptor) using the VCO control voltage sent from the IF-
569 board, to generate each CCD driving pulse or sample-
and-hold pulse. These pulse are sent to the DR-376 and
PA-173 boards.
PA-173 board
The CCD output is split into two channels. The PA-173
board is provided with a multiplexer which is used to
return the split signals to thier original state.
NR-66 board
The NR-66 board performs correlative double sampling so
as to extract a reset noise from the CCD output.
DU-1/RP-108 boards
The DU-1 and RP-108 boards mount the APR correction
circuit for the CCD.
HDC-750A
VA-158 board
The VA-158 board consists of the video amplifier, gain-up
amplifier, white balancing amplifier, white/black shading
correction circuits, test signal generator, diagnosis circuit
and so on.
The R, G and B video signals input from the CCD block
are passed through the differential amplifier and pre-white-
clip correction circuit. And then the residual component of
clocks is removed at the LPF. The differential amplifier
clamps the black level and also mixes the black shading
correction signal with the video signals.
The R, G and B video signals are passed through the pre-
set gain adjusting control, the black-set circuit, the gain-up
amplifier and white balancing amplifier sequentially and
are then output to the MX-59 board. The white balancing
amplifier performs the white shading correction too.
In addition, the VA-158 board has the test signal generator
which can generate two types of test signals. The test
signals can be used for various adjustments or maintenance
by switching the output signal from the CCD signal to
either of test signals. The adjustment data for the VA-158
board is stored in the EEPROM on the board.
MX-59 board
The R, G and B video signals from the VA-158 board are
input to the flare circuit at first. At the following amplifi-
ers, level adjustment is done and the pedestal is added to
the video signals. The resultant signals are output to the
PR-200 board. The matrix circuit generates the color
correction signal from the R, G and B video signals to
improve the color reproduction.
The knee aperture signal generated by the knee aperture
circuit is output to the PR-200 board to be mixed with the
R, G and B video signals.
The MX-59 board is provided with NAM Y signal genera-
tor for auto-iris function and the diagnosis circuit, too. The
adjustment data for the MX-59 board is stored in the
EEPROM on the board.
2-4. Circuit Description
2-3 (E)
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