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:
Jul. 30, 1996
Filed:
Sep. 30, 1994
Raymond J Chaney, Berkeley, GB;
Renishaw PLC, Gloucestershire, GB;
Abstract
An absolute interferometer has part of the beam paths making up its measuring and reference arms formed in a waveguide, and part formed in air. The part formed in the waveguide are common mode so that the path length difference is formed in air, thus minimizing inaccuracies in the measurements caused by temperature changes in the waveguide. Phase modulators in the waveguide enable interpolation of the fringe counts to be made to high resolution. The absolute interferometer may be combined with a tracking interferometer, and with air refractometers, all of which have parts of their measuring and reference arms in the waveguide in common mode and symmetrical with each other.