Self-calibrating system for detecting media movement by using capacitors as sensors

摘要: A sheet movement detection system for apparatus having a feed path includes first capacitor sensor including pair of parallel plate members located in opposing relation on opposite sides the plane at an upstream position and second members, which are correspondingly sized spaced to said downstream position. The sensors coupled circuit applies potentials across pairs so that output signals sensing means subtracted from one another. detects during lead edge through provides lead-edge indicating or velocity edge.