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:
Feb. 11, 1997
Filed:
Dec. 21, 1994
Applicant:
Inventors:
Alexander Straaijer, Eindhoven, NL;
Jan W Martens, Veldhoven, NL;
Assignee:
ASM Lithography, La Veldhoven, NL;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
359811 ; 359350 ; 359809 ; 359894 ; 359507 ; 355 67 ;
Abstract
A high-quality lens system (PL) is described, which system is rinsed with a gas having a low refractive index so as to reduce the influence of variations of ambient parameters on the optical behaviour. By adding a very small quantity of ozone to this gas, it is prevented that any deposit will be produced on the lens elements within the lens holder (PLH) as a result of decomposition of organic particles caused by UV radiation and precipitation of the decomposition products.