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:
Mar. 16, 1999
Filed:
May. 19, 1997
Satoru Fukuoka, Yamanashi-ken, JP;
Yukihiro Sugawara, Yamanashi-ken, JP;
Pioneer Video Corporation, Yamanashi-ken, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
An optical disc includes two transparent substrate layers each having a recording surface with a plurality of pits arranged concentrically or spirally. The plurality of pits represents information stored on the recording surface. Each transparent substrate layer has a thickness of 0.6.+-.0.03 mm. A reflecting layer is formed on each of the recording surfaces of the two transparent substrate layers. An inclining angle formed between a pit inner wall and a normal line of each transparent substrate layer is 20.degree.-55.degree., and pit depth is set to be .lambda./3.5N-.lambda./2.7N. .lambda. is defined as the wavelength of a laser beam incident the optical disc for reading the information recorded on the optical disc, and N is the index of refraction of each transparent substrate layer.