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:
Mar. 21, 1989
Filed:
Apr. 08, 1987
Donald W Zerrien, Jr, Elgin, IL (US);
James W Kopec, Winfield, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
In one aspect of the present invention, an angle measuring device is described for measuring the angle of a rotating rotor having a plurality of markings spaced thereabout. The device comprises: a sensor positioned adjacent the rotor for detecting the markings and generating a sensor signal in response thereto; an indicator device, responsive to the sensor signal, for generating a position signal indicative of the angular position of the rotor. Additionally, a timing circuit is used for measuring the time between contiguous sensor signals; and a comparator is used for comparing at least one of the measured times against at least one predetermined value and for generating a comparison output signal indicative thereof. Finally, a correction circuit is used, in response to the comparison output signal, for correcting the position signal to avoid inaccuracies due to such problems as unequal spacing between the markings.