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:
Apr. 02, 2013
Filed:
Sep. 17, 2010
Raymond Jay Barry, Lexington, KY (US);
Raymond Jay Barry, Lexington, KY (US);
Lexmark International, Inc., Lexington, KY (US);
Abstract
A method for detecting low toner in an electro-photographic toner cartridge having an optical sensor using a light beam to detect the presence or absence of toner in the cartridge includes transmitting to a processor a signal related to the strength of the light beam sensed as a paddle disposed within the cartridge rotates. The processor calculates an average value for the signal for each of a plurality of sets of paddle revolutions. The processor then calculates a variation value for the signal for each of the plurality of sets of paddle revolutions. The processor filters each variation value to determine a plurality of short term variation values. The processor monitors whether at least one short term variation value exceeds a first threshold. When the at least one short term variation value exceeds the first threshold, the processor signals that the toner level is low.