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:
Jan. 08, 1991
Filed:
Nov. 08, 1988
Douglas L Milne, Dundee, GB;
NCR Corporation, Dayton, OH (US);
Abstract
A linear variable differential transformer (42) produces an output voltage which varies linearly with movement of the axis of a movable axis roller (14) relative to the axis of a fixed axis roller (12) brought about by the passage of a sheet between the rollers. Circuits (154, 189) store a reference voltage representative of a minimum value of the output voltage during one revolution of the fixed axis roller, and subtracting circuits (162, 172) subtract the reference voltage from the output voltage when a single or multiple sheet is passing between the rollers so as to produce a difference value representative of the thickness of this sheet. A processor (178) samples the difference value a plurality of times during one revolution of the fixed axis roller, and provides an indication that a multiple sheet has passed between the rollers if at least a predetermined number of consecutive samples of the difference value exceed a predetermined value.