2-3. LED-318 BOARD(2) External Trigger Circuit
The trigger pulse that is input from the OTRIG IN�
The LED that is used to indicate the operating status of aconnector on the rear panel, is passed through CN750,
camera, is installed in the LED-318 board. When the mainwave-shaped by an inverter (IC751), pulse-width-narrowed
power of a camera is turned on, the LED turns on in green.by the differential circuit of C757 and R759, then sent to
When a camera receives a command to transfer the photocoupler (IC753). The input circuit and the outputthe video
signal, [JL801] goes HIGH, the LED turns on in orangecircuit are separated by the photocoupler (IC753) to protect
instead of green.the camera from external noise or adverse effects due to
the potential difference of the GND with that of external
equipment. The output signal of the photocoupler (IC753)
2-4. DCP-18 BOARDis sent to the timing generator IC (IC203) of the DP-109
board.
The DCP-18 board circuit consists of the built-in lens driveIn addition, the power supply ISO +5 V and GND (FGND)
and control circuit (DFW-VL500 only), external triggerthat are separated from other power supplies and GNDs,
circuit and microprocessor peripheral circuit.are supplied from the DC-DC converter circuit of the IF-
697 board, to the circuits before the photocoupler (IC753).
(1) Lens Control Circuit (DFW-VL500 only)
The lens control circuit includes the zoom control circuit(3) Microprocessor Peripheral Circuits
and the iris control circuit.The default adjustment data when shipped from the
The lens zoom and focus are controlled by the pre-driverfactory, and the parameters (that are specified by
(IC702) and the current driver (IC700). The pre-driver ICIEEE1394) that a camera must memorize, have been saved
receives serial data from the microprocessor and outputsin EEPROM (IC750) and are read out by the
the control signals that are required for the microprocessor drive IC(IC401) on the IF-697 board when
(IC700) and control zoom and focus. The drive IC sendsnecessary.
the control signal that is required for the lens unit viaThe camera can communicate with a personal computer
CN702.via RS-232C during adjustment at the factory. The
The iris control circuit consists of the operationaladjustment data is input and output through CN751 using
amplifiers (IC701, IC703, IC704) that drive the iris. Thethe RS-232C driver (IC754).
control voltage from the electronic volume control IC
(IC752) is input to these operational ICs, and their output
is sent to the lens unit.2-5. IF-697 BOARD
At the same time, the calibration signals of the Hall
elements that are located inside the lens unit, are sent to theThe IF-697 board circuit consists of a microprocessor that
lens unit via these operational amplifiers.controls a camera, the IEEE1394 circuit and the DC-DC
The switches S700, S701, S702 and S703 are the focusconverter.
FAR, focus NEAR, zoom TELE and the zoom WIDERegarding the IEEE1394 supporting circuit, the
switches. When any of these switches is pressed, theCAMLINK (IC402) controls the LINK layer that is
microprocessor (IC401) detects and controls the zoom andrequired by IEEE1394 of the interface block, and controls
focus accordingly.the video memory that is required for sending out video
data. The CAMLINK also generate the various timing
pulses.
The PHY-IC (IC406) is the physical layer (PHY) IC that is
required by IEEE1394 which is an interface standard. It
has a built-in PLL circuit and other circuits for generating
the clock to be used for data send/receive and
communication.
DFW-V500/VL500
2-2 (E) |
ACEC
