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:
Oct. 23, 2001
Filed:
May. 11, 2000
Masayuki Nishikawa, Higashiosaka, JP;
Sharp Kabushiki Kaisha, , JP;
Abstract
A two-group lens is comprised of a first lens and a second lens. The first lens is driven in an optical-axis direction by a magnetic circuit including a variable-distance use coil. As the first lens is driven, the second lens is also driven in an opposite direction to the first lens by a magnetic circuit including a mass-body driving coil, where the center-of-gravity position of movable part of an objective lens driver is kept at a generally constant position. The variable-distance use coil is disposed with the same gap as the mass-body driving coil. Thus, the distance between the first lens and the second lens can be held constant with a simple structure, without involving any complex structure, so that an accurate tracking can be achieved.