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. 21, 1992
Filed:
Mar. 13, 1989
Tadashi Miki, Osaka, JP;
Masayuki Kozuka, Moriguchi, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
Areas in an optical disk are classified into three categories including file areas, used areas, and erased areas for management purposes. An erasing process to convert a used area into an erased area is executed asynchronously with a writing process, thereby preventing any decrease in data transfer speed due to the effect of the erasing process upon the writing process. On the other hand, the file areas, used areas and erased areas are managed as continuous areas which are designated by the head position and the size or end position of the area. A file is preferentially assigned from an erased area or a used area of a large size. With such a construction, area management, such as an integration of the erased area or the like, can be easily performed. Also, the file can be assigned to the continuous areas, and the access speed can be improved.