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:
Nov. 30, 2004
Filed:
Jun. 27, 2003
Ricky E. Robbins, Harrodsburg, KY (US);
Lexmark International, Inc., Lexington, KY (US);
Abstract
A calibration resistor and a capacitance load are placed in parallel across the output of a voltage source and a first decay time is determined for the voltage to reach a second voltage from a first voltage after the voltage source is disconnected. With the calibration resistor electrically removed, N printheads of a printer and the capacitance load are placed in parallel across the voltage source output. In a first example, the voltage across the capacitance load at a second decay time, which is shorter than the first decay time, is determined and indicates at least one possibly shorted printhead when less than the second voltage. In a second example, the voltage across the capacitance load at the first decay time is determined and indicates at least one possibly shorted printhead when less than a third voltage which is less than the second voltage.