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. 25, 2000
Filed:
Apr. 24, 1998
Applicant:
Inventors:
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
360 7811 ; 360 7703 ;
Abstract
A holographic unit for applying light to a recording medium comprises an optical path, a first optical diffracting member, a second optical diffracting member, an optical condensing member, a first entrance/exit surface disposed at a predetermined first angle to a first reflecting surface, and a second entrance/exit surface disposed at a predetermined second angle to a second reflecting surface to project a plurality of light beams so that the plurality of light beams fall on a position sensing track formed on a recording medium perpendicularly to the surface of the recording medium.