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:
Jun. 21, 1994
Filed:
Jul. 02, 1991
Applicant:
Inventors:
Toshiyuki Oda, Chigasaka, JP;
Takashi Takeuchi, Fujisawa, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
3692751 ; 369 47 ; 369 48 ; 369111 ;
Abstract
An information recording disc having at least two bands of information provided thereon. Each of the bands contain at least one track with one of the at least two bands being a read-only area band or a write area band along the one track of the one band. Another of the at least two bands is a mixed area band having at least one read-only area and at least one write area at different portions along the track of the mixed area band. An information system utilizes the disc for writing and reading information to and from the disc.