Block Diagrams And Circuit Description; Circuit Description - Sony DIGITAL BETACAM DVW-707 Maintenance Manual

6-1. Circuit Description

(1) Camera Processing Block
(AD-155 board, DCP-17 board, ES-23 board)
AD-155 board
The AD-155 board consists of the A/D converter circuit
that converts the RGB analog signals supplied from the
CCD block to digital signal.
The analog RGB signals that are input from the CCD
block, pass through the respective pre-filters in accordance
with the WIDE and NORMAL sampling frequencies.
Outputs of the pre-filters are converted to the 12-bit digital
RGB signals of either 14 MHz (NORMAL) or 18 MHz
(WIDE) by the A/D converters. The digital RGB signals
are sent to the DCP-17 board.
DCP-17 board
The DCP-17 board consists of the following four blocks.
. The circuit block where the digital RGB signals that are
supplied from the AD-155 board, receive digital signal
processing, are converted to digital component signals
and are then converted to analog component signals to
be sent to the ES-23 board.
. The circuit block where the digital RGB signals that are
supplied from the AD-155 board, receive digital signal
processing, are converted to digital component signals to
be sent to the VTR block in the form of digital signals.
. The driver block that adds characters to the analog
composite signal supplied from the ES-23 board, and
outputs the analog composite signals with characters.
. The signal processing block that converts the analog
composite signals supplied from the ES-23 board to the
analog VF signals, and then outputs the analog VF
signals to viewfinder.
The digital RGB signal that are input from the AD-155
board, are sent to the shading correction IC where white
shading detection, error detection/correction and feedback
clamp detection processing are implemented.
At the same time, the white shading correction signals (R
WSH, G WSH, B WSH) and the feedback clamp control
signals (R FB, G FB, B FB) are sent to the CCD block.
Simultaneously, the black shading correction signals (R
BSH, G BSH, B BSH) are sent from the back shading
correction signal generator circuit to the CCD block, and
the test SAW signal is sent from the test SAW signal
generator circuit to the CCD block.
DVW-790WS/709WS/707
DVW-790WSP/709WSP/707P P1
Section 6

Block Diagrams and Circuit Description

The digital RGB signals that are output from the shading
correction IC, are buffered by the BF-74 board then sent to
the image enhancer IC where the digital RGB signals
receive the 1H delay-line processing that generates the
various detail signals which are sent to the process IC and
other circuit via other signal path than that of the main line
RGB signals.
This block contains the sync generator circuit that gener-
ates various sync signals.
The digital RGB signals that are output from the image
enhancer IC, are sent to the process IC where the digital
RGB signals take the following signal paths:
1 Up-converted to either 28 MHz (NORMAL) or 36
MHz (WIDE)
2 Matrix signal, aperture signal and detail signal are
added.
3 Receive pedestal control, knee correction, gamma
correction and white/black clip processing
4 Converted to the digital component signals (Y, R-Y,
B-Y)
This block contains the built-in color-bar signal generator
circuit and switching circuit between color-bar signal and
main line signal, and the output circuit of the Y, R, G and
B video signals for VF circuit where the video signal for
VF circuit is D/A-converted and is sent to the viewfinder
or the TEST OUT connector. The VF output circuit has
the function that allows the monitor selection IC to switch
video signals so that the video signal that is connected to
the GENLOCK IN connector can be monitored or the RET
video signal can be monitored on VF when CCU is
connected.
The digital component signals that are output from the
process IC, takes the two signal paths after passing through
the RC-69 and RC-75 boards
nected to the rate converter IC where the digital component
signals are converted of the rate to 27 MHz and are sent to
the DVP-17 board and the CI-21 board. The other signal
path is connected to the D/A converter where the digital
component signals are D/A converted and are sent to the
ES-23 board as the analog component signals (Y, R-Y, B-
Y).
*1 : As for the DVW-707/707P, the CN-1573 board is used.
*1
. One signal path is con-
6-1