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. 28, 1992
Filed:
Jul. 11, 1990
Gregory Menzenski, Ithaca, NY (US);
NCR Corporation, Dayton, OH (US);
Abstract
A method and apparatus for electronically determining when a ribbon cassette in a printer should be replaced. The ribbon cassette comprises a housing and an electrically conductive ink ribbon stored in the housing. The apparatus comprises a detection apparatus which includes a first conductor and a second conductor which pass through the housing and contact the ink ribbon, thereby enabling a signal to be generated when the electrical resistance of the ink ribbon equals a predetermined resistance. A controller coupled to the detection apparatus causes a message that the ribbon cassette needs to be replaced to be displayed on a display in response to the signal. The method entails generating a first signal corresponding to the electrical resistance of at least a portion of the ink ribbon; and then generating a second signal when the first signal equals a third signal corresponding to the predetermined resistance of the ink ribbon.