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:
Dec. 02, 1986
Filed:
Apr. 09, 1985
Applicant:
Inventors:
Eiji Nakamura, Yokohama, JP;
Yutaka Suenaga, Yokohama, JP;
Assignee:
Nippon Kogaku K.K., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350525 ; 350434 ; 350443 ;
Abstract
In dark field illumination apparatus for epi-illumination system, in order to attain the above and other objects, the present invention provides an annular light beam which is coaxial with the optical axis of the objective lens and is supplied along an optical path formed surrounding the objective lens. An annular condenser member is arranged near the object side end of the objective lens in such manner that the beam reaches the object surface while being concentrated in the direction toward the optical axis by the condenser member.