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. 19, 1991
Filed:
Aug. 13, 1990
Alfons Ernst, Traunreut, DE;
Johannes Heidenheim GmbH, Traunreut, DE;
Abstract
An incremental angle encoder of the invention has an encoder shaft connected with a first disk having an incremental angular graduation and a first and a second reference mark. A second disk is connected to this first disk via a reduction gear, on which a spiral-shaped reference scanning field is provided. A first scanning unit scans the incremental angular graduation to generate two scanning signals and the first reference mark to generate a first reference signal. A second scanning unit scans the second reference mark utilizing the spiral-shaped reference scanning field to generate a second reference signal. A specific offset, which indicates the number of revolutions of the encoder shaft, exists between the first reference signal and the second reference signal because of the spiral-shaped reference scanning field. An absolute angular measurement value for the encoder shaft is determined from the scanning signals and from the specific offset for the number of revolutions.