International Business Machines Corporation

George G Promis, Jr

John Charles Wilson

Gerald L Smith

Frederick W Johnson

Gary A Clark

A motor driving system which is particularly useful for driving scanning carriages in a continuously variable reducing electrophotographic copier. The motor driving system produces one of a number of different controlled and repeatable position acceleration and velocity profiles of the scanning carriage with respect to motion of the copier drum; a different position acceleration and velocity profile is produced for each reduction mode in a substantially continuous range of reduction modes. The motor driving arrangement includes a single control loop for driving a servo motor which provides the drive for the scanning carriage. A driving signal source produces a driving signal pulse train, each pulse representing a desired increment of motor travel, and a direction signal representative of the desired direction of travekl. A tachometer is responsive to servo motor motion and produces an output signal representative of the direction of motion; the output signal includes a series of tachometer pulses, each pulse representing a given increment of servo motor movement. A logic circuit couples the output of the tachometer, the driving signal pulse train and the direction signal to an up/down counter which is stepped in one direction for each driving signal pulse, and which is also stepped in another or one direction, respectively, for each tachometer pulse which represents a direction which is the same as or different from the direction of the direction signal. The output of the up/down counter, converted to analog form, provides an input signal to drive the servo motor. In order to control the acceleration, velocity and position profiles of the scanning carriage, the driving signal source produces a train of output pulses whose repetition rate is precisely controlled in relation to the motion of the drum. The driving signal source includes a counter which produces a pulse output each time a predetermined count is reached, the counter is stepped at a rate related to the velocity of the drum, and the repetition rate of the output pulses is controlled by providing a sequence of quantities, from a storage matrix, to alter the modulus of the counter in a predetermined pattern.

Motor driving system

Method and apparatus are described for job recovery when jamming of copies occurs in copying devices generating duplex copies electrophotographically from either simplex or duplex originals. Recovery from jams while copying the first side of simplex or duplex originals can normally be immediately effected during the initial, or normal, run, after clearing the jam. Recovery from jams during copying of the second side is effected by clearing the jammed copies from the copying device, optionally inserting blank sheets as the initial copying run is continued to flag the position of each of the removed jammed copies in the generated stack of copies, rerunning the originals through the copying device after completion of the initial copying run with duplex copies being generated only as necessary to replace jammed copies occurring during the initial run, and then inserting the duplex copies last made in the proper positions in the stack of copies made during the initial run, which copies replace the blank flagging sheets, if utilized. The apparatus includes a plurality of counters, memory registers and comparators interconnected by logic circuitry to semi-automatically effect job recovery due to jammed copies occurring during duplex copying from either simplex or duplex originals.

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Arvada, CO, United States of America

George G Promis, Jr