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:
Jun. 27, 1989
Filed:
May. 22, 1987
Hiroyuki Nakamura, Kobe, JP;
Masashi Ito, Settsu, JP;
Toshiki Itoi, Nara, JP;
Akifumi Hashimoto, Neyagawa, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
In an objective lens driving unit, an objective lens (12) is fixed to a coil bobbin (11), which has a focus drive coil (13a) wound therearound with its axis coaxial with the axis of the objective lens (12) and tracking dive coils (13b, 13c) wound thereon with their axes perpendicular with the axis of the objective lens (12), and the focus drive coil (13a) and the tracking drive coils (13b, 13c) are put in an open magnetic field produced by a magnetic yoke (14) having permanent magnets (15a, 15b), which makes magnetic flux to cross the coils, thereby to drive the objective lens (12); thus the size of the unit is decreased and made light, and further, the weight of the moving part is made light, to boost sensitivity thereby.