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:
May. 01, 1979
Filed:
Jul. 30, 1976
Applicant:
Inventors:
Chiaki Kojima, Yokohama, JP;
Yuzuru Yanagisawa, Fujisawa, JP;
Takashi Otobe, Yokohama, JP;
Hiroshi Ohki, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N / ; G11B / ;
U.S. Cl.
CPC ...
358128 ; 1791 / ; 1791 / ; 346 / ;
Abstract
In a record disk having a spiral groove in a surface thereof with the depth of the groove varying along the latter for representing recorded information, such as video signals; the groove has an inverted bell-shaped cross-section which is symmetrical about the median of the groove with each of the opposite side surfaces of the groove, at any location therealong, being defined approximately by the equation