Xerox Corporation

John M Randall

Joseph A Swift

LeRoy A Baldwin

Clifford K Friend

John M Schneider

William S Franks, Jr

Allen W Lee

A power supply circuit which converts an A.C. signal into an output signal that combines A.C. and D.C. voltages components. The circuit uses a voltage doubler topology with transistors. The transistors are controlled by waveform generators, which generate a series of pulses. By adjusting the duty cycle of the pulses, the appropriate D.C. voltages components can be formed. By adjusting the duty cycle of the positive output producing pulses and negative output producing pulses relative to each other, the required A.C. signal can be adjusted. A scavengeless developer in a xerographic machine requires three bias voltage inputs. The power supply circuit can be attached to a transformer connected to an appropriate A.C. power source to produce the required voltage signals to control the operation of the developer.

Power supply topology enabling bipolar voltage output from a single

A device for neutralizing static electric charge on a surface comprising a support means, a plurality of resilient, flexible thin fibers having an electrical resistivity of from about 2.times.10.sup.3 ohm-cm to about 1.times.10.sup.6 ohm-cm., the fibers being supported by the support means in such manner that the fibers are oriented and extend in a uniform direction, in a brush like configuration from the support means so that the distal ends of the fibers may extend toward a surface which has a static charge which one wishes to neutralize. Preferably, the resilient fibers have a resistivity of from about 4.times.10.sup.4 ohm-cm. to about 4.times.10.sup.5 ohm-cm., and are arranged in a linear array of spaced discrete bundles of fibers in a conductive potting composition in the support holder. Preferably the fibers are made of a partially carbonized polyacrylonitrile fiber and the device may be used in an electrostatographic reproducing machine having at least one dicorotron charging device.

Static eliminator

A web drive system consisting of two independent speed controlled servos used to drive at least two webs is provided for use in a photoelectrophoretic web machine. The servo drive systems cooperate in the transporting of the webs to eliminate speed differential tensions between the two webs held together by friction and electrical tacking force. The first servo system may be bi-polar controlled. The second servo system may be uni-polar controlled and switched between speed and torque control modes. When the webs are held apart, the second servo system will be in speed control and whenever the webs are in contact, the second servo system is switched to the torque control mode.

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Fairport, NY, United States of America

John M Randall