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:
May. 07, 2002
Filed:
Oct. 13, 2000
James D. Anthony, Victor, NY (US);
Kenneth M. Patterson, Hilton, NY (US);
William A. Hameister, Penfield, NY (US);
Heidelberger Druckmaschinen AG, Heidelberg, DE;
Abstract
The invention provides a diagnostic system for a densitometer in an image-forming machine. An image-forming machine with a densitometer diagnostic system may have a photoconductor, one or more chargers, an exposure machine, a toning station, and a densitometer. A densitometer diagnostic system for an image-forming machine may have an emitter, a collector, amplifier circuitry, and diagnostic circuitry. The diagnostic circuitry reduces the drive current to the emitter in the densitometer by a known or calculable value. The output voltage from the amplifier circuitry in the densitometer is reduced in proportion to the reduction in the drive current. To perform diagnostic testing of the densitometer, a first output voltage is obtained from the densitometer without the diagnostic circuitry connected. A second output voltage is obtained from the densitometer with the diagnostic circuitry connected. When the difference in first and second output voltages matches an output voltage specification, the densitometer is functional. The diagnostic circuitry may be removed from the densitometer when not in use. Alternatively, the densitometer may have a switch to disconnect the diagnostic circuitry when not in use.