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:
Nov. 17, 1992
Filed:
Mar. 04, 1991
Keishi Kubo, Moriguchi, JP;
Tatsuo Itou, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A displacement detector device has a source of laser beam; a diffraction grating for separating the laser beam into a plurality of beam components; a filter for shielding the beam components other than the two beam components of .+-. primary order produced by the diffraction grating; a wavelength plate operable to vary the polarized state of one of the two beam components of .+-. primary order; a lens element for focusing the two beam components of .+-. primary order on a displacement plane and a reference plane, respectively; and a photosensor. The two beam components of .+-. primary order focused on the reference and displacement planes, respectively, are subsequently reflected therefrom and are then collimated by the lens element after having again entered the lens element in substantially overlapped relationship. The two beam components emerging from the lens element are again diffracted by the diffraction grating, and the photosensor detects an interfering component of the beam components of primary order.