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:
Aug. 29, 1978
Filed:
Mar. 30, 1977
Jeffrey Isherwood, Enfield, GB;
Abstract
For the lateral guidance of travelling webs, three photoelectric detectors are arranged under one margin of the web in a transverse line such that the path of light from a light source, on the other side of the web plane, to a first of the detectors is blocked by the web, the light path to a second of the detectors is partially blocked by the web, and the third detector is fully exposed to the light source, when the web is in its normal lateral position. Signals from the three detectors are combined in such a manner that a signal is derived representing the extent to which the second detector is covered by the web, the value obtained being corrected for variations in light source intensity and for web translucence.