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:
Jul. 10, 2001
Filed:
Apr. 27, 1999
Asahi Kasei Kabushiki Kaisha, , JP;
Abstract
An optical information recording medium comprising a thin plastic substrate of 0.6 mm or thinner, wherein the substrate is protected against strain without being limited by a film structure and a film formation condition. A single-layer or multilayer thin film (,) is formed on a plastic disk-like substrate having a center hole (,). This thin film (,) has a strain relief area (,) inside a recording area (,). This strain relief area (,) is formed by setting an outer diameter of an undeposited inner portion (,) to a value satisfying the following formula (1), for example: A,≦A,≦−0.172P+0.163 where A,: diameter of center hole, A,: outer diameter of undeposited inner portion, P: total strain occurring in thin film when film depositing.