Patent Number: 6,169,721

Title: Two-disc laminated optical recording medium

Abstract: An optical recording medium has a substrate having an annular grooves, a recording layer including an organic coloring matter and formed on the substrate, and a metallic reflection layer. The recording layer has a thickness so as to have an absorbance between 0.65 and 0.75. Information is recorded in the recording layer by a laser beam having a wavelength between 600 and 700 nm, using an objective lens having a numerical aperture between 0.55 and 0.70.

Inventors: Takishita; Toshihiko (Yamanashi-ken, JP), Hanzawa; Shinichi (Yamanashi-ken, JP), Murakami; Shigenori (Yamanashi-ken, JP), Kondo; Atsushi (Yamanashi-ken, JP), Mitsumori; Ayumi (Yamanashi-ken, JP), Kusama; Miki (Yamanashi-ken, JP), Matsukawa; Makoto (Yamanashi-ken, JP)

Assignee: Pioneer Electronic Corporation

International Classification: G11B 7/244 (20060101); G11B 7/24 (20060101); G11B 7/249 (20060101); G11B 7/258 (20060101); G11B 7/007 (20060101); G11B 007/24 (); B32B 003/00 ()

Expiration Date: 01/02/2018