【発明の名称】光情報記録媒体

Title:

【発明の名称】光情報記録媒体

Document Type and Number:

Japanese Patent JPH07109660

Kind Code:

B2

Abstract:

PURPOSE:To satisfy the standard of block error rate specified by the compact disk (CD) standard by specifying the pencil hardness, coefft. of thermal expansion and shrinkage rate of a protective layer. CONSTITUTION:The optical information recording medium 1 has a light- transmitting substrate 2, light-absorbing layer 3 formed on the substrate 2, light-reflecting layer 4 deformed on the light-absorbing layer 3, and a protective layer 5 formed on the light-reflecting layer 4. The coefft. of thermal expansion alphaof the protective layer 5 is specified to 1.5 X 10<-5> <= alpha <= 9.0 X 10<-5> (1/ deg.C) in the use environment temp. range of -15 deg.C to 70 deg.C, so that the protective layer 5 shows same thermal changes in volume as that of the substrate 2. Thereby, the optical information recording medium 1 as a whole has little warpage when heated. Thereby, reproduction signals which satisfy the CD standard can be obtained.

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WO/2007/018398	SUPER-RESOLUTION INFORMATION RECORDING MEDIUM, RECORDING/REPRODUCING APPARATUS, AND RECORDING/REPRODUCING METHOD
JPH10188355	OPTICAL DISK
JPH0751300	INDUSTRIAL APPLICABILITY A method for forming a preformatted optical disk substrate and a mold used for the molding method

Inventors:

TAKAGISHI YOSHIKAZU
HAMADA EMIKO
ARAI JUJI
FUJII TOORU
MATSUMOTO TAKANOBU

Application Number:

JP2611690A

Publication Date:

November 22, 1995

Filing Date:

February 07, 1990

Export Citation:

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Assignee:

TAIYO YUDEN KK

International Classes:

G11B7/24; G11B7/24035; G11B7/254; G11B7/257; (IPC1-7): G11B7/24

Domestic Patent References:

JP63188837A
JP210533A
JP3232130A
JP3232132A

Attorney, Agent or Firm:

Hiroshi Ikezawa

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