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:
Mar. 17, 1987
Filed:
May. 10, 1984
Hiroo Fujita, Tanashi, JP;
Citizen Watch Co., Ltd., Tokyo, JP;
Abstract
A surface condition measurement apparatus comprises a laser light source producing a light beam which is converted into two light beams of mutually different frequencies by an acousto-optical element, these light beams are split into two pairs directed in different directions with one pair serving to generate a beat-frequency signal used as a phase reference signal by heterodyne interference and the other pair being focussed onto a body surface to be reflected therefrom and with an electrical signal being generated from the reflected light as a beat-frequency signal, a phase difference between the latter signal and the reference signal being measured and processed to derive a difference in surface height between the surface points from which the light beam pair are reflected.