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. 24, 1994
Filed:
Jun. 26, 1992
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A method for detecting a minute displacement of a probe includes an emission from a light source of two light beams having different polarizing directions. The light beams are subsequently diverged by a first lens so as to pass through a beam splitter towards a separating prism. The light beams having passed through the prism are separated into first and second measuring beams which are subsequently focused by a second lens on first and second, spaced reflecting surfaces. The first and second measuring beams are then reflected by the first and second reflecting surfaces, respectively, so as to enter respective photodetectors after having passed through the separating prism, the beam splitter and a polarizing beam splitter for passing therethrough the first and second measuring beams or reflecting them depending on the polarizing direction of the incoming light. The first and second photodetectors outputs respective signals indicative of the associated positions of foci which are then processed by a signal processing circuit to provide an indication of the minute displacement of the probe.