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. 03, 2007
Filed:
Dec. 28, 2005
Akinori Ohkubo, Utsunomiya, JP;
Tokuyuki Honda, Tokyo, JP;
Hideki Morishima, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An immersion optical system that condenses light from a light source toward a first surface includes a lens having a concave lens surface closest to the first surface, a liquid being filled in a space between the concave lens surface and the first surface, wherein a conditional equation d>L/[2×tan {arcsin(NA/ni)}] is met, where d is a distance between a first point and a second point when the distance becomes maximum between the first point on the concave lens surface and the second point on the first surface in a direction substantially orthogonal to the first surface, L/2 is a maximum distance from the second point to an edge of an irradiation area of the light on a first surface, NA is a numerical aperture of the immersion optical system, and ni is a refractive index of the liquid.