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. 17, 1987
Filed:
Jun. 28, 1985
Michel R Croset, Hampshire, GB;
Martin Lane, Hampshire, GB;
Roy E Winchester, W. Sussex, GB;
David R Worsley, Hampshire, GB;
De La Rue Systems Limited, London, GB;
Abstract
A method and apparatus for monitoring the passage of sheets past at least one sensing assembly (48,49). The sensing assembly (48,49) generates an output signal whose level varies in accordance with a characteristic of the sheets, for example the thickness of the sheets. The method comprises for the or each sensing assembly, presetting a first threshold (62) spaced by a predetermined amount from a datum output signal level (57) when no sheet is sensed, the predetermined amount being such that the first threshold (62) is not passed as a result of random noise variations in the output signal but is passed during the passage past the sensing means of all sheets which it is desired to monitor. The size of the output signal from the sensing means (48, 49) relative to the datum level is monitored when the output signal first passes the first threshold (62) corresponding to the passage of a first sheet. Single, double, and triple sheet thresholds (63, 64, 67) are generated from a monitored size and thereafter the output signal is monitored to sense when it passes one or more of the thresholds.