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. 28, 1985
Filed:
Oct. 28, 1982
Walter Schmitt, Traunreut, DE;
Dr. Johannes Heidenhain GmbH, Traunreut, DE;
Abstract
An incremental path measuring instrument is disclosed which includes a plurality of reference marks R.sub.1 . . . R.sub.n which are interposed between respective code marks C.sub.1 . . . C.sub.n. The reference marks and code marks are applied alternately and serially to the reference track included on the measuring scale. A scanning unit is included in the measuring device for scanning in series the reference marks and the code marks. Each of the code marks is unique, and only one of the two adjacent code marks and the respective reference mark must be scanned by the scanning unit in order to identify the reference mark unambiguously. When absolute position values are allocated to respective individual reference marks, the incremental path measuring device can operate in a quasi-absolute mode of operation, since then the position of each of the reference marks is established with respect to a predetermined zero point. Preferably, the code marks each contain beginning of block and end of block symbols in addition to the identifying information needed to identify the respective reference marks. The disclosed path measuring device includes an evaluation circuit which includes a circuit which automatically adapts the trigger threshold required for signal evaluation to the actual amplitudes of the signals.