Optical recording medium

• US 6,985,429 B2
• Filed: 12/26/2001
• Issued: 01/10/2006
• Est. Priority Date: 12/28/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Tanaka, Shintaro, Aratani, Katsuhisa, Okawa, Naoki
• Primary Examiner(s): CASTRO, ANGEL A
• Application Number:
  US10/220,207
• Publication Number:
  US 20030137924A1
• Time in Patent Office: 1,476 Days
• Field of Search: 369/288, 369/286, 369/283, 369/275.2, 428/64.1, 428/64.4, 428/457, 430/270.12, 430/270.11
• US Class Current: 369/288
• CPC Class Codes: G11B 7/24038 Multiple laminated recording layers
• CPC Class Codes: G11B 7/258 of reflective layers
• CPC Class Codes: G11B 7/259 based on silver
• CPC Class Codes: G11B 7/26 Apparatus or processes specially adapted for the manufacture of record carriers

Abstract

According to the present invention, there is provided an optical recording medium including at least an information recording layer and a reflective film in which the reflective film is comprised of an AgCu alloy thin film containing Cu the content of which is greater than or equal to 3.0 [atomic %] and less than or equal to 6.5 [atomic %]. Thus, the optical recording medium can be made inexpensive and weather resistance of the optical recording medium can be improved, thereby making it possible to avoid characteristics of the optical recording medium from being deteriorated even after it has been stored for a long time.

Claims

1. In an optical recording medium including at least an information recording layer and a reflective film, an optical recording medium characterized in that said reflective film is made of an AgCu containing alloy containing Cu the content of which is greater than or equal to 2.0 [atomic %] and less than or equal to 9.0 [atomic %] and said AgCu containing alloy is made of an AgCu containing either of ternary alloy and quaternary alloy containing one or two chemical elements of Fe, Ni, Mo, W and whose total content of said chemical elements is greater than or equal to 0.5 [atomic %] and less than or equal to 8.1 [atomic %].

2. In an optical recording medium in which at least a first information recording layer and a second information recording layer are laminated to each other, an optical recording medium characterized in that said first information recording layer has a translucent reflective film formed thereon, said second information recording layer has a reflective film formed thereon, said translucent reflective layer is made of an AgCu containing alloy containing Cu the content of which is greater than or equal to 2.0[atomic %] and less than or equal to 9.0[atomic %], said AgCu containing alloy is made of an AgCu containing either of ternary alloy and quaternary alloy containing one or two chemical elements of Fe, Ni, Mo, W and whose total content of said chemical elements is greater than or equal to 0.5[atomic %] and less than or equal to 8.1[atomic %] and information is reproduced from said second information recording layer with irradiation of light that has passed through said first information recording layer.

5. An optical recording medium according to claim 2, or 3, wherein said first information recording layer is formed on a first substrate molded by transparent material, said second information recording layer is formed on a second substrate, said first and second substrates are laminated to each other through a transparent adhesive agent layer in such a manner that information recording layers thereof are facing to each other and information is reproduced from said first and second information recording layers with irradiation of light from said first substrate side.

3. In an optical recording medium including at least an information recording layer and a reflective film, an optical recording medium characterized in that said reflective film is formed of an AgCuPd containing alloy thin film containing Cu the content of which is greater than or equal to 1.5 atomic % and less than or equal to 9.0 atomic % and Pd the content of which is greater than or equal to 0.1 atomic % and less than or equal to 2.0 atomic % said AgCu containing alloy is made of an AgCuPd containing either of quatemary alloy and quinary alloy containing one or two chemical elements of Al, Ti, Fe, Ni, Mo, W and whose total content of said chemical elements is greater than or equal to 0.5 atomic % and less than or equal to 8.1 atomic %.

4. In an optical recording medium in which at least a first information recording layer and a second information recording layer are laminated to each other, an optical recording medium characterized in that said first information recording layer has a translucent reflective film formed thereon, said second information recording layer has a reflective film formed thereon, said translucent reflective film is made of an AgCuPD containing alloy containing Cu the content of which is greater than or equal to 1.5 atomic % and less than or equal to 9.0 atomic %, and Pd the content of which is greater than or equal to 0.1 atomic % and less than or equal to 2.0 atomic % said AgCuPd containing alloy is made of an AgCuPd containing either of quatemary alloy and quinary alloy containing one or two chemical elements of Al, Ti, Fe, Ni, Mo, W and whose total content of said chemical elements is greater than or equal to 0.5 atomic % and less than or equal to 8.1 atomic % and information is reproduced from said second information recording layer with irradiation of light that has passed through said first information recording layer.