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. 12, 1996
Filed:
May. 19, 1995
Ricoh Company, Ltd., Tokyo, JP;
Abstract
An optical encoding apparatus is provided which is not affected by fluctuation of wavelength of a light beam due to temperature change, without sacrificing resolution of measurement. The optical encoding apparatus includes a light source for emitting a light beam, a light beam condenser for condensing the light beam emitted by the light source, a first diffraction grating to which light beams condensed by the light beam condenser are directed, and a second diffraction grating to which light beams exiting from the first diffraction grating are directed. Additionally, a displacement information obtaining device is included for obtaining information regarding a displacement of one of the first and second diffraction gratings, the information being obtained according to a twice-diffracted beam and a twice-transmitted beam incident upon the second diffraction grating. The twice-diffracted beam is diffracted by the first diffraction grating, and the twice-transmitted beam is transmitted through the first diffraction grating.