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. 17, 1990
Filed:
Apr. 06, 1988
Applicant:
Inventors:
Yoshie Kodera, Yokohama, JP;
Hisashi Kabe, Kamakura, JP;
Tetsu Ohishi, Hiratsuka, JP;
Jun Matsumoto, Odahara, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ;
U.S. Cl.
CPC ...
369275 ; 369288 ; 430945 ; 430270 ;
Abstract
An optical disc consists of a base plate, a reflective thin layer and a protective thin layer. As the base plate, polymethylmethacrylate is used. Since defects in the protective thin layer are a function of defects in the base plate, in order to reduce defects in the protective thin layer, defects in the base plate are reduced. For reducing defects in the base plate, a copolymer of methyl methacrylate and methyl acrylate is used.
Kodera, Yoshie. (1990). Optical information medium having a base plate made of (U.S. Patent No. 4918683). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/4918683
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile