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:
Aug. 27, 2013
Filed:
Jan. 09, 2009
Tadashi Arai, Utsunomiya, JP;
Tadashi Arai, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A method of evaluating an imaging performance of a projection optical system, comprising a step of specifying a polarization change of the projection optical system, which represents a relationship between a polarization state of light impinging on the projection optical system and the polarization state of the light exiting from the projection optical system, a first calculation step of calculating a value of a parameter having a correlation with the polarization change of the projection optical system specified in the specifying step, and a second calculation step of calculating an index value representing the imaging performance in a state that the projection optical system has the polarization change specified in the specifying step, based on an amount of change in the index value representing the imaging performance upon changing the value of the parameter by a unit amount, and the value of the parameter calculated in the first calculation step.