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.

Date of Patent:
Jun. 25, 2019

Filed:

Aug. 23, 2018
Applicant:

International Business Machines Corporation, Armonk, NY (US);

Inventors:

Richard A. Haight, Mahopac, NY (US);

James B. Hannon, Lake Lincolndale, NY (US);

Rudolf M. Tromp, North Salem, NY (US);

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G01B 11/02 (2006.01); G01B 9/02 (2006.01); G01B 11/14 (2006.01); G03F 7/20 (2006.01); G01B 11/06 (2006.01);
U.S. Cl.
CPC ...
G01B 9/02 (2013.01); G01B 11/026 (2013.01); G01B 11/0608 (2013.01); G01B 11/14 (2013.01); G03F 7/70775 (2013.01);
Abstract

Methods and systems for measuring a distance include measuring a first interference pattern between a lens and a target surface using a light source at a first wavelength. A second interference pattern is measured between the lens and the target surface using a light source at a second wavelength, different from the first wavelength. An absolute measurement of a distance between the lens and the target surface is determined based on the first interference pattern and the second interference pattern.


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