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. 23, 2011
Filed:
Mar. 23, 2010
Masataka Shiratsuchi, Kawasaki, JP;
Yoshinori Honguh, Yokohama, JP;
Masatoshi Hirono, Kanagawa, JP;
Riki Ogawa, Kanagawa, JP;
Shinji Sugihara, Tokyo, JP;
Masataka Shiratsuchi, Kawasaki, JP;
Yoshinori Honguh, Yokohama, JP;
Masatoshi Hirono, Kanagawa, JP;
Riki Ogawa, Kanagawa, JP;
Shinji Sugihara, Tokyo, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In an automatic focus adjusting mechanism, a test sample having a patterned surface is mounted on a mount table, and an light beam passing through a slit formed in a field stop is applied to the patterned surface of the test sample. The light beam reflected from the test sample is split into two segment light beams. Focus adjusting aperture stops having respective apertures formed rhomboid are provided across the optical paths of the segment light beams. The amounts of the segment light beams passing through the rhomboid apertures are detected by light receiving units. Based on the difference between the detected light amounts, the position of the mount table is controlled by the focus adjusting unit.