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:
Feb. 15, 1983
Filed:
Sep. 10, 1981
Joseph E Cunningham, Jr, Boulder, CO (US);
Philip T Gianos, Boulder, CO (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A copier fuser roll's temperature is accurately maintained by supplying selected half-cycles of current from a power supply to a heater in accordance with signals from a temperature sensor. Each sequential half-cycle is assigned a unique digital input number which accesses a table of digital output numbers having values chosen to correspond to one or more half-cycles. Sensor signals are sampled and digital temperature error numbers, determined by the fuser roll temperature and a desired roll temperature, are derived. The temperature error and output numbers are compared and, whenever a comparison occurs, the corresponding half-cycle of current operates the heater. Thus, depending upon the difference between a desired and the actual roll temperature, variable numbers of evenly spaced complete half-cycles, having a total positive-to-negative ratio approaching unity, are selected.