Browse Prior Art Database

Original Publication Date: 1992-Aug-31
Included in the Prior Art Database: 2004-Apr-06

Publishing Venue

Xerox Disclosure Journal


The status of an electrical or mechanical component within a machine may be monitored by, for example, the electrical current required to drive a motor associated with the component. Commonly know signature analysis techniques may be used in conjunction with such components or subsystems to detect problems which might lead to poor performance, or even failure, of the component. Electrophotographic systems employ many such motors or similar electromechanical devices to enable the operation of a xerographic or similar marking system. Accordingly, the signature analysis technique may be utilized in such a system to monitor the operation of a paper tray elevator motor in a paper feed Subsystem. It is commonly known to utilize one or more switches to monitor the operation of the elevator, as described in United States Patent 5,017,972 issued to Daughton et al. on May 21, 1991. However, monitoring of the current requirements of the elevator drive motor may allow detection of a problem before a catastrophic failure. For example, the over-travel of the elevator, which is commonly detected by safety switches, and which may potentially damage the paper feed or other subsystems, can be detected by signature analysis techniques.