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:
May. 30, 1995
Filed:
Jun. 01, 1993
Applicant:
Inventors:
Takanori Maeda, Saitama, JP;
Toru Akiyama, Saitama, JP;
Fumitaka Kotaka, Saitama, JP;
Noriaki Murao, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369111 ; 369112 ; 369120 ; 369 4437 ; 369 4441 ; 2502015 ;
Abstract
A plurality of tracks are spirally arranged in a group on an optical disc. The tracks in the group are simultaneously radiated by laser beams. Adjacent tracks in the group are disposed at a radial distance d1, and adjacent spots of the laser beams on the tracks are disposed at a radial distance ds which is smaller than the distance d1.