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. 14, 1998
Filed:
Aug. 23, 1996
Glen Castore, Roseville, MN (US);
M&M Precision Systems Corporation, West Carrollton, OH (US);
Abstract
A method and an apparatus for a precision optical distance measuring device which can be used to determine both external and internal target geometries. The beam from a frequency modulated laser diode is split into reference and target beams. A closed loop control system modulates the amplitude of the reference beam to maintain a balance between the power in the target return beam and the reference beam. This enables the sensor to operate with targets of widely varying reflectivity and across a broad range of angles of incidence of the target beam to the target. The reference and target return beams interfere at a detector producing a beat wave. The beat frequency is linearly related to the distance of the target from the sensor. The frequency of the beat wave is determined to high precision, thus giving the position to high precision.