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. 25, 1999
Filed:
Dec. 11, 1997
Makoto Takahashi, Nagano, JP;
Takashi Kikukawa, Nagano, JP;
Isamu Kuribayashi, Nagano, JP;
Junji Tominaga, Tsukuba, JP;
TDK Corporation, Tokyo, JP;
Abstract
The invention provides a phase change type optical recording medium enabling an increased jitter concomitant with repeated overwriting to be restrained or substantially eliminated. In the optical recording medium comprising a phase change type recording layer on a substrate, the recording layer has a lower dielectric layer in contact with a lower side thereof and an upper dielectric layer in contact with an upper side thereof, and at least one of the upper and lower dielectric layers contains zinc sulfide, and further includes a metal element A that has a standard free energy for forming a sulfide thereof lower than a standard free energy for forming ZnS at 0 to 1,000.degree. C. The ratio of metal element A to all metal elements in the zinc sulfide-containing dielectric layer is less than 2 at %. Metal element A is typically Ce, Ca, Mg, Sr, Ba, and Na.