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:
Jan. 02, 1996
Filed:
Oct. 18, 1993
Abstract
Disclosed herein are an optical recording method of conducting recording/reading out for information by irradiating a laser beam at a wavelength of not more than 500 nm onto a recording layer of an optical disc having a track pitch of not less than 0.4 .mu.m and less than 0.9 .mu.m, the laser beam being incident from a disc substrate side of the optical disc using an objective lens having numerical aperture of 0.55 to 0.70, a recording area for information recording on the disc substrate being a flat area not having a guide groove for each track, and the disc substrate having a in-plane birefringence of not more than 20.times.10.sup.-6 and a vertical birefringence of not more than 300.times.10.sup.-6, and an optical recording medium suitable for use in the optical recording method.