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:
Apr. 26, 1994
Filed:
Jul. 07, 1992
Mikio Yamamuro, Zushi, JP;
Akihiko Doi, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
Disclosed is an objective lens position detecting system which comprises an optical head for holding an objective lens for focusing a light beam on a storage disk having tracks formed thereon, a first detector having a first light-emitting element and a first light-receiving element and provided in a vicinity of the objective lens, unconnected thereto, for detecting the position of the objective lens, a second detector having a second light-emitting element and a second light-receiving element and provided in a vicinity of the objective lens, unconnected thereto, and apart by a predetermined distance from the first detector, for detecting the position of the objective lens, a plate, connected to the objective lens, for reflecting light from the first light-emitting element to the first light-receiving element and reflecting light from the second light-emitting element to the second light-receiving element, whereby the first detector and the second detector detect the position of the objective lens from values of the reflected light, a circuit for outputting a difference between detection signals received from the first detector and the second detector, and a circuit for receiving the detection signals from the first and second detectors and adjusting the amounts of radiation from the first light-emitting element and the second light-emitting element so as to cause the sum of the detection signals to approach a predetermined target value.