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. 12, 1991
Filed:
May. 02, 1990
Alfred Affa, Stein/Traun, DE;
Dr. Johannes Heidenhain GmbH, Traunreut, DE;
Abstract
A position measuring apparatus of the type that includes a measuring scale and a scanning unit is provided. The measuring scale includes a measuring graduation track and a reference mark track associated with the measuring graduation track. The reference mark track includes a plurality of reference marks, a predetermined number of which are further designated as marked or unmarked. The scanning unit provides for scanning the measuring scale and evaluating the signal produced by such scanning. The apparatus also includes an operating switch associated with the scanning unit. The operating switch provides for selection of at least two modes of operation of the scanning unit: a first mode in which all the reference marks on the reference mark track are evaluated, and a second mode in which marked or unmarked reference marks on the reference track are evaluated.