Sony BVP-570, Maintenance Manual

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2-7 (E)
BVP-570
2-4. Circuit Description
DA-88A board
The monochrome signal for VF (VF Y) sent from the PR-242 board goes through a lowpass filter and is
output to the IF-510 board. The wide-band luminance signal Hi-Ys is output via a lowpass filter to the
camera adaptor as the Y signal. The Y signal is used for generating the two signals. One is the Y RF
signal for TRIAX transmission and the other is the VTR Y signal. The modulated chroma signal C goes
through a black clamp circuit and lowpass filter and is added to the Hi-Ys. The resultant is output to the
IF-510 board as the VBS signal. The Y, R-Y and B-Y signals, that are input from the PR-242 board as the
digital video signals, are aligned in phase with video signals in another channels by a digital delay line.
The resultant is digital-to-analog converted and is then output via a lowpass filter to the IF-510 board. On
the other hand, an analog component signal is generated in combination with the above-mentioned Hi-Ys
signal, R-Y and B-Y signals. The analog component signal is controlled, on the level adjustment and
reference signal addition, by the AT-126 board according to equipment connected to the camera (VTR or
CCU). The analog component signal is output to external equipment via the 68P interface connector.
IF-510 board
Input signals at the IF-510 board are as follows;
Signals from the DA-88A board: VF Y, VBS, Y, R-Y and B-Y
Signals from external equipment: Reference signal for external synchronization, Return video signal
By combination with these signals, the IF-510 board outputs the following signals.
.
VBS OUT signal
Output via a buffer amplifier to external equipment.
. VBS OUT signal for RM
Output to an interface connector for a remote control unit RM-P9. Using the setup menu, a character
signal to confirm the menu setting can be mixed to this signal.
.
TEST OUT signal
With the signal select switch at the right top of the camera, the above-mentioned VBS OUT signal, the
VBS OUT signal for RM or the VF Y signal can be selected as a TEST OUT signal output at the TEST
OUT connector.
.
VF OUT/MONI OUT signal
The same signal is output as the VF OUT signal and the MONI OUT signal. One of the return video or
reference signal selected by S1, VF Y, and VBS on the IF-510 board, is selected. The selected signal is
mixed with a center marker and safety-zone pulse, and is then output. The VF OUT signal is output at
the VF connector and the MONI OUT signal is output at the 68P interface connector.
.
R/G/B output signals
The Y, R-Y and B-Y signals are converted to the R, G and B signals by a matrix circuit. The converted
signals are output at the 68P interface connector.
.
Y/R-Y/B-Y output signals for VF
These signals are for a color viewfinder. A character signal and SKIN GATE signal are mixed with the
above-mentioned Y, R-Y and B-Y signals. The resultants are output to the VF.
In addition, the IF-510 board is equipped with the following circuits.
.
HD/VD external sync circuit
When displaying the return video or reference signal on the viewfinder screen, it is necessary to
synchronize the cursor signal with those signals. And a sync signal is separated from those signals to
generate the external HD and VD signals, and the resultant is sent to the cursor signal generation circuit
on the PR-242 board.
.
Transmits the SKIN GATE signal from DA-88A board to the CCU via the 68P interface connector.