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:
Apr. 06, 2010
Filed:
Jan. 28, 2008
Seima Kato, Utsunomiya, JP;
Seima Kato, Utsunomiya, JP;
Canon Kabushiki Kaisha, , JP;
Abstract
The invention provides a measurement apparatus which measures a wavefront aberration of an optical system to be measured, the apparatus includes a measurement mask which is inserted on an object plane of the optical system to be measured, and includes a plurality of reflection units configured to generate spherical waves by reflecting light, the measurement mask including a reflection layer configured to reflect the light, a first layer which is stacked on the reflection layer, has a plurality of openings, and is made of a first substance, and a second layer which is stacked on the first layer, has a window configured to expose a region in which the plurality of openings are arrayed, and is made of a second substance different from the first substance, wherein the plurality of reflection units are formed by portions of the reflection layer, which are exposed through the plurality of openings.