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:
Dec. 02, 2003
Filed:
Mar. 10, 2000
Ko Ishizuka, Omiya, JP;
Hidejiro Kadowaki, Yokohama, JP;
Yasushi Kaneda, Urawa, JP;
Shigeki Kato, Utsunomiya, JP;
Takayuki Kadoshima, Utsunomiya, JP;
Sakae Horyu, Hachioji, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An interference measuring apparatus has an optical system for dividing a coherent light beam into two light beams, causing the divided two light beams to pass along discrete optical paths and making them into linearly polarized light beams orthogonal to each other and given modulation to the phase of the wave front of at least one of them, and again superposing the wave fronts of the linearly polarized light beams one upon the other, a light dividing member for dividing the light beams superposed one upon the other by the optical system into a plurality of light beams, a rock crystal plate formed with a predetermined level difference in conformity with the incidence positions of the plurality of light beams, a polarizing plate for taking out each light beam transmitted through the rock crystal plate with a 45° polarized component, and a plurality of light receiving elements for individually receiving the light beams taken out by the polarizing plate, a plurality of different interference phase signals being provided by the reception of lights of the light receiving elements.