Circuit Description - Sony HDVF-C30W Maintenance Manual

1-4. Circuit Description

PR-267 board
The input Y, Pb and Pr signals are passed through the
buffer and the pre-filter and are A/D-converted to the 10-
bit digital signals. Then resultant signals are sent to the
FPGA.
The digital input Y, Pb and Pr signals are clamped inside
the FPGA, receive the BRIGHT, CONTRAST and PEAK-
ING controls, and are finally converted to the RGB signals
that are output to LCD. The above controls are realized by
A/D-converting the analog control voltages from the VR-
280 board and are supplied to FPGA.
The H1 signal and H2 signal are generated from the sync
signal by the two comparators. The H1 signal extracts the
zero-cross point of the three-level sync signal and the H2
signal extracts the sync signal near the zero-cross point.
The H1 and H2 signals are supplied to FPGA that gener-
ates the H and V sync signals. The LCD drive pulse signals
are generated from the H and V sync signals. The LCD
drive pulse signals that are thus generated are supplied to
LCD together with the RGB video signal and the LCD
gamma correction voltage.
The various controls from the camera and VF are sent
through IIC and are processed by FPGA from which the
control commands are distributed to the respective circuits
as the control signals as necessitated.
RE-208 board
The RE-208 board contains the following three types of
voltage regulator. 1. The voltage regulator supplying the
analog and digital signal processing, generating the 3.1 V
regulated voltage. 2. The voltage regulators supplying the
LCD drive voltages, generating the 10.5 V, 20 V and -7.2
V regulated voltages. 3. The voltage regulator supplying
the CCFL drive regulated voltage.
The maximum contrast of LCD is set by the variable
resistor located inside the LCD. The LCD contrast can be
controlled within the range with the use of CONTRAST
under the maximum contrast set by the above variable
resistor.
VR-280 board
The VR-280 board contains the two sets of BRIGHT,
CONTRAST and PEAKING controls. One set of these
controls is for the external control. The other set of these
controls is for the internal control. Either the external or
the internal controls can be selected with the use of the
SEL switch. The VR-280 board contains the tally lamp
drive circuit that turns on or off the TALLY lamp in
accordance with the command supplied from the camera.
1-2 (E)
The VR-280 board contains also the switch that inverts the
scanning direction from the right or left of display screen.
This switch is interlocked with the viewfinder barrel
presence so that the appropriate scanning direction is
automatically selected as the viewfinder barrel is installed.
SW-1092 board
The SW-1092 board contains the tally, zebra, marker,
B&W and MAG function selector switches. The status
information of these selector switches is sent to the PR-267
board.
1-5. Input and Output Signals of
Connectors
VF (20P MALE)
(EXTERNAL VIEW)
Pin No. Signal Name I/O
1 S-DATA IN/OUT
2 NC
3 POWER IN
OFF CTL
4 SCK IN
5 NC
6 NC
7 NC
8 G TALLY IN
9 NC
10 NC
11 NC
12 Y VIDEO IN
13 VIDEO GND
14 Pb VIDEO IN
15 Pr VIDEO IN
16 NC
17 R TALLY IN
18 NC
19 UNREG GND
20 UNREG IN
Specifications
TTL level
No connection
POWER ON : OPEN
POWER OFF : GND
TTL level
No connection
No connection
No connection
ON : 5 V
OFF : GND
No connection
No connection
No connection
1.0 V p-p Zo = 75 Z
GND for VIDEO
0.7 V p-p Zo = 75 Z
0.7 V p-p Zo = 75 Z
No connection
ON : 5 V
OFF : GND
No connection
GND for UNREG
DC 10.5 V to 17 V
HDVF-C30W