Optical recording medium

• US 6,667,088 B2
• Filed: 01/31/2001
• Issued: 12/23/2003
• Est. Priority Date: 01/31/2000
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Miki, Takeshi
• Primary Examiner(s): Kelly, Cynthia H.
• Assistant Examiner(s): Ferguson, Lawrence D
• Application Number:
  US09/774,421
• Publication Number:
  US 20010044000A1
• Time in Patent Office: 1,056 Days
• Field of Search: 428/64.4, 428/64.1, 428/65.6
• US Class Current: 428/823.1
• CPC Class Codes: G11B 11/10584 characterised by the form, e.g. comprising mechanical protection elements
• CPC Class Codes: G11B 11/10591 for improving write-in properties, e.g. Curie-point temperature
• CPC Class Codes: G11B 11/10593 for improving read-out properties, e.g. polarisation of light
• CPC Class Codes: G11B 2007/24306 transition metal elements of groups 3-10
• CPC Class Codes: G11B 2007/25706 containing transition metal elements (Zn, Fe, Co, Ni, Pt)
• CPC Class Codes: G11B 2007/25708 containing group 13 elements (B, Al, Ga)
• CPC Class Codes: G11B 2007/2571 containing group 14 elements except carbon (Si, Ge, Sn, Pb)
• CPC Class Codes: G11B 2007/25713 containing nitrogen
• CPC Class Codes: G11B 2007/25715 containing oxygen
• CPC Class Codes: G11B 2007/25716 containing sulfur
• CPC Class Codes: G11B 7/24 Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the arrangement of information on the carrier G11B7/007
• CPC Class Codes: G11B 7/2531 comprising glass
• CPC Class Codes: G11B 7/2533 comprising resins
• CPC Class Codes: G11B 7/2534 polycarbonates [PC]
• CPC Class Codes: G11B 7/2542 consisting essentially of organic resins
• CPC Class Codes: G11B 7/2578 consisting essentially of inorganic materials
• CPC Class Codes: G11B 7/259 based on silver
• CPC Class Codes: Y10T 428/21 Circular sheet or circular blank

Abstract

Information is recorded on or reproduced from an optical recording medium (10) with irradiation of light from the opposite side of a substrate (2). In this optical recording medium (10), a reflection layer (6) is deposited on the substrate (2). This reflection layer (6) is made of an AgPdCu alloy thin layer or an AgPdCuAl alloy thin layer. A surface roughness (Ra) of this reflection layer (6) is less than 0.75 nm. A dielectric layer (3) is deposited on this reflection layer (6), and a heat control layer (1) is deposited on this dielectric layer (3). This heat control layer (1) is made of an AgPdCu alloy thin layer. A surface roughness (Ra) of this heat control layer (1) is less than 0.75 nm. A recording layer (4), a dielectric layer (5) and an organic protection layer (7) are deposited on this heat control layer (1). This optical recording medium can improve heat characteristics and reduce a disk noise.

Claims

1. An optical recording medium comprising:

a reflection layer deposited on at least one substrate;

a dielectric layer deposited on said reflection layer;

a heat control layer deposited on said dielectric layer; and

a recording layer directly deposited on and in contact with said heat control layer, wherein information is at least recorded on or reproduced from said recording layer with irradiation of light from the opposite side of said substrate, said heat control layer is made of an AgPdCu alloy thin layer, and said reflection layer comprises an AgPdCu-type alloy thin layer.

2. An optical recording medium according to claim 1, wherein said heat control layer has a surface roughness Ra less than 0.75 nm.

3. An optical recording medium according to claim 1, wherein said heat control layer has a surface roughness Ra less than 0.75 nm and said reflection layer has a surface roughness Ra less than 0.75 nm.

4. An optical recording medium according to claim 1, wherein said reflection layer is made of an AgPdCuAl alloy thin layer.

5. An optical recording medium according to claim 2, wherein said reflection layer is made of an AgPdCuAl alloy thin layer.

6. An optical recording medium according to claim 3, wherein said reflection layer is made of an AgPdCuAl alloy thin layer.