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. 20, 1997
Filed:
Mar. 12, 1996
Applicant:
Inventors:
Assignee:
Dr. Johannes heidenhain GmbH, Traunreut, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01B / ; G01B / ;
U.S. Cl.
CPC ...
356349 ; 356358 ;
Abstract
An absolute measuring interferometer having a measuring interferometer, a tunable laser emitting a laser beam and a control interferometer for adjusting the air wavelength of the laser beam. The control interferometer adjusts the air wavelength of the laser beam to a specific wavelength value at the ends of each measuring cycle. The wavelength of the tunable laser is continually tuned within the specific wavelength interval where the phase change of the interference signal is continually detected during the wavelength modulation process. An absolute measurement is determined by a simple mathematical relationship between the measured wavelength and phase changes.