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:
Jan. 18, 2005
Filed:
Jul. 30, 2002
Soichi Owa, Kumagaya, JP;
Naomasa Shiraishi, Saitama, JP;
Issey Tanaka, Hadogaya, JP;
Yasuhiro Omura, Kumagaya, JP;
Soichi Owa, Kumagaya, JP;
Naomasa Shiraishi, Saitama, JP;
Issey Tanaka, Hadogaya, JP;
Yasuhiro Omura, Kumagaya, JP;
Nikon Corporation, Tokyo, JP;
Abstract
An optical system attains good optical performance without substantially receiving the effects of birefringence even when using an optical material having intrinsic birefringence. An optical system that includes at least one radiation transmissive member that transmits light having a wavelength of 200 nm or less has an optical axis that substantially coincides with a crystal axis [100] or a crystal axis optically equivalent to the crystal axis [100]. In addition, an optical system can include: a first group of radiation transmissive members that transmits light having a wavelength of 200 nm or less and having an optical axis that substantially coincides with a crystal axis [100] or a crystal axis optically equivalent to the crystal axis [100]; and a second group of radiation transmissive members that transmits light having a wavelength of 200 nm or less and having an optical axis that substantially coincides with a crystal axis [100] or a crystal axis optically equivalent to the crystal axis [100]; wherein the first group of radiation transmissive members and the second group of radiation transmissive members have a positional relationship rotated substantially 45° about the optical axis relative to each other.