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:
May. 24, 1977
Filed:
Jul. 09, 1975
Jurgen Erdmann, Waldkirch, DT;
Erwin Sick Optik-Elektronik, Waldkirch, DT;
Abstract
A photoelectronic instrument for measuring the length of an object by means of a slim scanning beam of light which, when not interrupted by the object, activates a photoelectric transducer, wherein, for the purpose of determining trigger points when half the light beam is obscured at the beginning and reemerges at the end of the period of cut-off, irrespective of the absolute magnitude of the light flux of the unobscured light beam, a circuit is provided for differentiating, with respect to time, a signal obtained from the photoelectric transducer and proportional to the magnitude of the light flux (light flux signal U.sub.1), a signal proportional to the differential quotient (dU.sub.1 /dt) thus obtained being rectified, multiplied by a preset factor (p.T), and the product of the multiplication and the light flux signal (U.sub.1) being applied to the inputs of a comparator functioning as a coincidence circuit for generating an output signal (U.sub.4) which, subject to an appropriate selection of the factor (p.T), abruptly changes when ##EQU1## WHERE U.sub.o is the light flux signal of the unobscured scanning light beam.