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:
Jun. 20, 1989
Filed:
Oct. 16, 1986
Nobuyoshi Tsuboi, Ibaraki, JP;
Atsumi Watanabe, Hitachi, JP;
Yoshio Sato, Hitachi, JP;
Satoshi Shimada, Hitachi, JP;
Hiroshi Sasaki, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A light spot determining a first condition that an optical recording medium is cooled after being heated to a temperature exceeding a first temperature and a light spot determining a second condition that the optical recording medium is cooled after being heated to a temperature exceeding a second temperature higher than the room temperature and not exceeding the first temperature higher than the second temperature, namely, the two light spots are radiated onto the optical recording medium and in the same guide track thereof wherein signals are recorded and erased on the optical recording medium by controlling the spot diameter of each light spot and/or the light intensity thereof.