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:
Jul. 20, 1999
Filed:
Mar. 12, 1997
Akihiko Shimizu, Yokohama, JP;
Ricoh Company, Ltd., Tokyo, JP;
Abstract
The invention provides an optical information recording medium capable of optionally setting the capacitance of the ROM and keeping the physical continuousness in the ROM track and the RAM track. The medium is the optical information recording medium in the land/groove recording system in which the information is recorded both in the convex groove track called land L and in the concave groove track called groove G, and it includes commonly in a sheet of medium a ROM area constructed with the pre-pit row previously formed on the basic substrate and a RAM area capable of being additionally written by the user. The track pitch of the pre-pit row in the ROM area is equal to that of the groove. The RAM area exists on the plain portion between the just adjacent pre-pit rows in the ROM area and on both portions of the land and the groove.