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. 14, 1987
Filed:
Nov. 15, 1984
Kenji Ohta, Yao, JP;
Akira Takahashi, Nara, JP;
Tetsuya Inui, Nara, JP;
Takao Hyuga, Soraku, JP;
Hideyoshi Yamaoka, Matsubara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An optical memory disc includes a glass substrate on which a plurality of concentric circular guide grooves (or a spiral groove) are formed for tracking purposes. A centering plate is secured to the glass substrate in a manner that the center of a circular opening formed in the centering plate is exactly adjusted to the center of the plurality of concentric circular guide grooves (spiral groove). The circular opening formed in the centering plate is utilized to drive the optical memory disc on a turntable. Since the circular opening is not formed directly in the glass substrate, the center adjustment is easily conducted, and there is no possibility that the glass substrate is damaged when the circular opening is formed.