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:
Sep. 18, 1990
Filed:
Dec. 19, 1988
Abstract
An optical head assembly for use with an optical disk apparatus includes a magnetic circuit block having permanent magnets each being elongate in a track traversing direction and a yoke for forming a magnetic circuit which conducts a magnetic field generated by the permanent magnets. The yoke includes a first through hole extending in a focusing direction, magnetic gaps located at opposite sides of the first through hole in the track traversing direction and individually accommodating the permanent magnets, and a second through hole for admitting the light beam issuing in the track traversing direction to guide it to the first through hole. The first through hole and magnetic gaps each has a cross-section relatively long in the track traversing direction. A beam deflector is loosely fitted in the first through hole for deflecting in the focusing direction the light beam which is incident thereto from the second through hole. The beam deflector is supported by a carriage. An objective lens focuses the light beam deflected by the beam deflector in the focusing direction onto the recording medium surface. The objective lens is mounted on a lens holder which is in turn mounted on the carriage movably in the focusing direction. Guide members support the magnetic circuit block and carriage movably in the track traversing direction along the recording medium surface.