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:
Feb. 03, 2015
Filed:
Mar. 08, 2013
Canon Kabushiki Kaisha, Tokyo, JP;
Yoshiki Maeda, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
The method for measuring profile of an aspheric surface projects an illumination light onto the aspheric surface and introduces a reflected light reflected by the aspheric surface to a sensor through an optical system. The method provides, to a wavefront of the illumination light, a curvature bringing an absolute value of an angle of the reflected light to a smaller value than a maximum value of absolute values of angles of optical system side peripheral rays, locates an exit pupil such that the absolute value of the reflected light angle is smaller than the maximum value, provides, to a sensor conjugate surface, a curvature and a position causing rays of the reflected light not to intersect on the sensor conjugate surface. The sensor conjugate surface, the wavefront of the illumination light and the aspheric surface have a same one of convex and concave surfaces toward a same direction.