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Web Control Systems
Edge Position Control Systems(Sensors)
Overview |  Specifications |    



The Photohead is the sensor of an EPC (Edge Position Control) system. It uses optical means to detect the edge of a strip (web).
The sensor signal is transmitted to an amplifier, and the amplified output signal is forwarded to a hydraulic jet pipe type controller or a servo valve, controlling the strip edge, so that it remains at the determined position.
If the operating environment of the Photohead is exposed to airborne dust, or if there is the risk that oil or water droplets etc. could fall onto the Photohead projector lens, use a sensor with the air purge specification.

  • The Photohead utilizes parallel light flux and detects the edge position of a strip (web) electrically.

Applications of Photohead EPC System


Pay-off reel system


Steering roller system (Intermediary guide roller)


Power supply Adjust the voltage supplied from the amplifier to:
PH30 : 6V DC
PH31 : 12V DC
Output Voltage Voltage proportional to variation of light intensity at the silicon light sensor element (mV).
Sensitivity: Detects positional variations of 0.1mm in a strip (opaque web).
Compressed air consumption for air purge specification 400NL/min (at 0.05MPa)
Allowable back pressure 0.05MPa
Paint color Silver
Ambient temperature -10 to +60℃
Range of measurement 20mm
Body material Aluminum alloy castion
Light source: 12V tungsten bulb
Mass PH30 : 3kg
PH31 :
PH31-3 300 200 270 540 554 31
PH31-4 400 200 320 640 654 33
PH31-5 500 200 370 740 754 36
PH31-6 600 200 420 840 854 38
PH31-7 700 400 470 940 954 40
PH31-8 800 400 520 1040 1054 42
PH31-9 900 400 570 1140 1154 44