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:
Nov. 29, 1988
Filed:
Jul. 22, 1986
Takashi Toyooka, Sayama, JP;
Norio Ohta, Sayama, JP;
Yutaka Sugita, Tokorozawa, JP;
Kazuo Shigematsu, Saitama, JP;
Atsushi Saito, Ichikawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In case of rewriting data by means of an erasable optical disc memory recording new data after having erased a series of data already stored, directory data written in an optical disc memory in order to control the written data are transferred to an external directory memory and write-in and read-out are controlled by using the directory memory. For rewriting data, which have been already recorded and which are recorded under a specified file name, the data are not erased and renewed data are written in another recording region, where recording is possible. The data, which have become unnecessary as the result of renewal, are erased during a period of time, when the optical disc memory is not accessed.