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Low Speed Mechanical Damping of Daisy Wheel Drive In An Impact Printer

IP.com Disclosure Number: IPCOM000065971D
Original Publication Date: 1979-Jan-01
Included in the Prior Art Database: 2005-Feb-19

Publishing Venue

IBM

Related People

Authors:
Mathews, RD [+details]

Abstract

The present structure provides for the damping of a stepper motor drive which drives the pin wheel or daisy wheel in an impact printer. Such damping is necessary when the stepper motor drive is moved into the stop mode at a particular print point. In stepper motors, the controlling algorithm decelerates the motor as the stop position is approached, based upon encoder feedback. Some level of oscillation is always present at a stop position. Thus, due to variations in motor characteristics, the oscillation at a stop position may be significant enough to produce erroneous signals from the encoder. The present approach superimposes upon the conventional stopping mechanism in a stepper motor a velocity sensitive frictional damping, i.e.