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. 16, 2002
Filed:
Oct. 21, 1999
Hitachi, Ltd., Tokyo, JP;
Abstract
An optical recording disk intended only for the reproduction of a main information and used by a information management system has the attachment of a memory in which data for the management of the main information is written and read out easily and reliably. The memory has associated electromagnetic coupling means for transacting the record management data with and receiving power from a recording/reproduction apparatus. The electromagnetic coupling means is built in the memory or disposed in an annular or spiral form on the disk. The transmission frequency band for data transaction and power supply is set outside the main information reproduction frequency band. The memory is disposed in or on an appropriate plastic layer of the disk depending on the usage of the disk, and located in the inner or outer section of the recording medium forming area on the disk depending on the transmission band. This low-cost optical disk can be manufactured at a high reliability and high yield.