Browse Prior Art Database

STACKER ELEVATOR FEEDBACK CONTROL

IP.com Disclosure Number: IPCOM000026302D
Original Publication Date: 1991-Apr-30
Included in the Prior Art Database: 2004-Apr-05
Document File: 2 page(s) / 61K

Publishing Venue

Xerox Disclosure Journal

Abstract

A feedback control algorithm for regulating a copy sheet output stacker elevator in electrophotographic copy and printing machines is disclosed. The algorithm relies upon compensating for variables such as mechanical tolerances, power level variations, and torque changes in a decrementing elevator used to maintain a constant distance as accumulated paper is moved downward. An elevator encoder system produces one encoder pulse per millimeter downward movement of an elevator tray. The total number of encoder pulses are compared to a decrement reference value representing complete displacement of the fully loaded elevator. If the encoder pulse value is not in close agreement with the decrement reference value, a feedback compensating correction scheme is invoked to establish a new elevator decrement compensating reference value. The new value is stored in nonvolatile memory and is used on subsequent start-up.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 88% of the total text.

Page 1 of 2

XEROX DISCLOSURE JOURNAL

STACKER ELEVATOR FEEDBACK Proposed Classification CONTROL U.S. C1. 271/094 Vernon W. Ulrich Int. C1. B65h 03/12

A feedback control algorithm for regulating a copy sheet output stacker elevator in electrophotographic copy and printing machines is disclosed. The algorithm relies upon compensating for variables such as mechanical tolerances, power level variations, and torque changes in a decrementing elevator used to maintain a constant distance as accumulated paper is moved downward. An elevator encoder system produces one encoder pulse per millimeter downward movement of an elevator tray. The total number of encoder pulses are compared to a decrement reference value representing complete displacement of the fully loaded elevator. If the encoder pulse value is not in close agreement with the decrement reference value, a feedback compensating correction scheme is invoked to establish a new elevator decrement compensating reference value. The new value is stored in nonvolatile memory and is used on subsequent start-up.

Advantages include: (1) correction of variables that fluctuate over a long time period; (2) provides a means for the electrophotographic device to monitor its own paper handling and processing performance and report potential failure to a service representative; and (3) automatic compensations of the indexing function of the elevator due to differences in source current levels. (60 or 50 Hz).

XEROX DISCLOSURE JOURNAL - Vol. 16...