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.

Date of Patent:
Nov. 19, 2002

Filed:

Oct. 27, 1999
Applicant:
Inventors:

John W. Sadler, Belmont, CA (US);

Kenneth L. Staton, San Carlos, CA (US);

Assignee:

Agilent Technologies, Inc., Palo Alto, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J 1/20 ;
U.S. Cl.
CPC ...
G01J 1/20 ;
Abstract

An inner control loop controls the relative position of a surface to be scanned with respect to a focal plane. An outer control loop responds to the location of the surface to be scanned with respect to a focal plane of the scan lens to generate a setpoint for the inner control loop. A sample-and-hold element disposed between the inner and outer control loops is switched by an edge or defect detector. It is preferred that the outer control loop has a time constant in the range of three to ten times longer than that of the inner control loop. The sample-and-hold element provides a gradual state transition upon the occurrence of an edge or a surface defect.


Find Patent Forward Citations

Sadler, John. (2002). Method and apparatus for dynamic focus control with error rejection (U.S. Patent No. 6483091). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/6483091

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

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