Patent ID: 7633256
Filing Date: 2009-12-15
Classification: G02B,G05B

Abstract:
1. A method of correcting encoder eccentricity in an image forming device that uses encoder feedback signals to generate speed and position counts to control the speed and position of a rotary encoder, the method comprising: receiving a plurality of pulse trains indicative of the speed of the rotary encoder; receiving a clocking signal having a frequency greater than the pulse trains; generating a series of periodic sampling points; calculating a corrected position count based at least partly on a first position count that is determined by counting a number of cycles of the clocking signal that elapse between a sampling point and a transition of a first of the plurality of pulse trains and a second position count based upon a second of the plurality of pulse trains; and adjusting the speed of the rotary encoder and maintaining a substantially constant value tor the corrected position count to effect position control.