The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 1981
Filed:
Dec. 06, 1979
George G Promis, Arvada, CO (US);
Gerald L Smith, Broomfield, CO (US);
John C Wilson, Longmont, CO (US);
International Business Machines Corporation, Armonk, NY (US);
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. 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.