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:
Sep. 11, 2001
Filed:
Jan. 07, 2000
Shinji Wakui, Utsunomiya, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
An active vibration isolator includes a vibration isolation platform on which an object to be isolated from vibration is mounted, an air-spring actuator which supports the vibration isolation platform, the air-spring actuator including a valve, which is subjected to feedback drive, a vibration measurement device which measures vibration of the vibration isolation platform and outputs acceleration and velocity signals, a position measurement device which measures position of the vibration isolation platform and first, second and third feedback loops. The first feedback loop feeds back an output of a force measurement device, which measures a working force applied by the air-spring actuator to the vibration isolation platform, thereby controlling the working force supplied by the air-spring actuator. The second feedback loop has a PI compensator and signals of the vibration measurement device are fed back to an input side of the compensator, for producing damping and spring effects which act upon the platform. The third feedback loop feeds back an output from the position measurement device, thereby positioning the platform at a designated position.