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:
May. 31, 1994
Filed:
Jun. 13, 1990
Hideo Yamasaki, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
In an electro-magnetic actuator, an objective lens is mounted on a lens holder which is elastically supported by two leaf springs and a focusing coil is wound around the lens holder. The lead springs is fixed on a carriage to which tracking coil is also fixed. Guide roller mechanisms are provided on the both sides of the tracking coil and are slidably mounted on guide rails, respectively. The tracking coil are so arranged as to be extended in magnetic gaps of magnetic circuits disposed between the carrier and the guide rails. In each of the magnetic circuit, first and second yokes are so faced to each other as to defined the magnetic gap, a pair of permanent magnets are interposed between the first and second yokes, a third yoke also so faced to the second yoke as to defined the magnetic gap, a pair of permanent magnets are also interposed between the second and third yokes, and a permanent magnet is provide at the first yoke to apply a magnetic flux to the focusing coil.