04650983 is referenced by 133 patents and cites 3 patents.

A focusing apparatus for projection optical system is provided with a projection optical system and an image-forming optical system. The projection optical system is disposed to project an image of an alignment mark formed on a photo mask or reticle onto a light-reflective substrate and also to reverse-project onto the photo mask the light image of the alignment mark projected on and reflected by the substrate. The image-forming optical system forms an overlap image from the reverse-projected reflected image and the alignment mark on the photo mask.

Title
Focusing apparatus for projection optical system
Application Number
6/667890
Publication Number
4650983
Application Date
November 2, 1984
Publication Date
March 17, 1987
Inventor
Kyoichi Suwa
Kanagawa
JP
Agent
Shapiro and Shapiro
Assignee
Nippon Kogaku
JP
IPC
G01J 1/36
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