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:
Jan. 27, 2004
Filed:
Oct. 25, 2001
Toshiyuki Tanaka, Moriguchi, JP;
Seiichi Nagatome, Yamatokoriyama, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
In an objective lens actuator, when an action force generation force including a focus coil and a magnetic circuit generates an action force for displacing an objective lens holder in a focus direction of an optical disk, a leaf spring supports the magnetic circuit with respect to an actuator base, in such a manner that the magnetic circuit can be rotated about an arbitrary point in the leaf spring, by a reaction force of the action force. At the same time, the equation a=I/Mh is satisfied, where M is a mass of the magnetic circuit, I is a moment of inertia of the magnetic circuit about a center of gravity, a is a distance between the center of gravity of the magnetic circuit and a line of action in a direction of the action force, and h is a distance between a center of rotation in the leaf spring and the center of gravity of the magnetic circuit. As a result, even if the reaction force of the action force acting on the objective lens holder is generated, stable focus servo can be performed, and the actuator can be downsized with a simple structure.