# US 8,465,822 B2 · Optical recording medium

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- Number: US 8,465,822 B2
- Document ID: US8465822B2
- Status: Granted
- Kind: B2
- Application number: 13/183,704
- Filed: 2011-07-15
- Published: 2012-02-02
- Granted: 2013-06-18
- Earliest claimed: 2010-07-29
- Assignees: Sony Corporation
- Applicants: Kotaro Kurokawa; Shigeki Takagawa
- Inventors: Kotaro Kurokawa; Shigeki Takagawa
- Web page: https://patentgrep.com/patent/US8465822B2

## CPC

- G11B 7/24038: Multiple laminated recording layers
- G11B 7/2578: consisting essentially of inorganic materials
- G11B 7/259: based on silver
- G11B 2007/24312: {group 14 elements (e.g. Si, Ge, Sn)}
- G11B 2007/24314: {group 15 elements (e.g. Sb, Bi)}
- G11B 2007/24316: {group 16 elements (i.e. chalcogenides, Se, Te)}
- G11B 2007/25706: {containing transition metal elements (Zn, Fe, Co, Ni, Pt)}
- G11B 2007/25708: {containing group 13 elements (B, Al, Ga)}
- G11B 2007/2571: {containing group 14 elements except carbon (Si, Ge, Sn, Pb)}
- G11B 2007/25713: {containing nitrogen}
- G11B 2007/25715: {containing oxygen}
- Y10T 428/21: Circular sheet or circular blank
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

An optical recording medium includes a support substrate and a semi-transmissive recording layer. The semi-transmissive recording layer includes a first dielectric layer, a semi-transmissive semi-reflective layer, a second dielectric layer, a phase change recording material layer, and a third dielectric layer that are sequentially stacked in that order on the support substrate. The semi-transmissive semi-reflective layer contains silver. The second dielectric layer has a stack structure including a lower layer disposed at the interface on the semi-transmissive semi-reflective layer side and an upper layer disposed on the phase change recording material layer side of the lower layer. The lower layer is composed of indium oxide or a composite oxide of indium oxide and tin oxide. The upper layer is composed of tantalum oxide, gallium oxide, zirconium oxide, or niobium oxide.

## Claims

### Claim 1

An optical recording medium comprising:
a support substrate; and
a semi-transmissive recording layer including (a) a first dielectric layer, (b) a semi-transmissive semi-reflective layer, (c) a second dielectric layer, (d) a phase change recording material layer, and (e) a third dielectric layer that are sequentially stacked in that order on the support substrate,
wherein,
the semi-transmissive semi-reflective layer contains silver,
the second dielectric layer has a stack structure including a lower layer disposed on the semi-transmissive semi-reflective layer and an upper layer disposed on the lower layer,
the lower layer is composed of indium oxide or a composite oxide of indium oxide and tin oxide, and
the upper layer is composed of tantalum oxide, gallium oxide, zirconium oxide, or niobium oxide.

### Claim 2 (depends on 1)

The optical recording medium according to claim 1, wherein the lower layer in the second dielectric layer is composed of a composite oxide of indium oxide and 50 mol % or less of tin oxide.

### Claim 3 (depends on 1)

The optical recording medium according to claim 1, wherein the phase change recording material layer is composed of at least one of germanium, bismuth, antimony, and tellurium.