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. 20, 1990
Filed:
Feb. 17, 1989
Applicant:
Inventors:
Tadahiro Yamaguchi, Saitama, JP;
Toshikazu Yoshino, Saitama, JP;
Assignee:
Pioneer Electronic Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; G01D / ;
U.S. Cl.
CPC ...
369284 ; 369283 ; 369291 ; 369280 ; 346137 ;
Abstract
An optical disc is disclosed in which a pair of circular disc substrates are arranged in confronted relation with each other with their signal recording layers being directed inwardly and are bonded to each other through spacers at inner and outer peripheral portions. A vent hole is formed in a main surface of one of the disc substrates. A disc label is bonded on the disc substrate so as to cover the vent hole.