Inventors:
George G. Promis - Arvada CO
Gerald L. Smith - Broomfield CO
John C. Wilson - Longmont CO
Assignee:
International Business Machines Corporation - Armonk NY
International Classification:
G05B 2419
Abstract:
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.