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. 15, 2006
Filed:
Nov. 08, 2005
Chiaki Terasawa, Utsunomiya, JP;
Hiroyuki Ishii, Utsunomiya, JP;
Takashi Kato, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
A catadioptric projection optical system for projecting an image of an object onto an image plane through two intermediate image formations. The catadioptric projection optical system includes a first optical system, for receiving light from the object, including a plurality of lenses, a second optical system, for forming the image of the object on the image plane, including a plurality of lenses, and a third optical system disposed optically between the first optical system and the second optical system. The third optical system includes a first concave mirror and a second concave mirror. The light is reflected by the first concave mirror then by the second concave mirror to be directed to the second optical system along a z-shaped optical path, and the first, second and third optical systems have a common straight optical axis.