JPS6450250A - Optical disk substrate - Google Patents

Optical disk substrate

Info

Publication number
JPS6450250A
JPS6450250A JP62206272A JP20627287A JPS6450250A JP S6450250 A JPS6450250 A JP S6450250A JP 62206272 A JP62206272 A JP 62206272A JP 20627287 A JP20627287 A JP 20627287A JP S6450250 A JPS6450250 A JP S6450250A
Authority
JP
Japan
Prior art keywords
substrate
information recording
hub
plane
recording area
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP62206272A
Other languages
Japanese (ja)
Inventor
Norio Goto
Hideo Tanide
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP62206272A priority Critical patent/JPS6450250A/en
Publication of JPS6450250A publication Critical patent/JPS6450250A/en
Pending legal-status Critical Current

Links

Landscapes

  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

PURPOSE:To suppress the double refraction of a substrate generated due to thermal stress from being increased, by providing a clamping member at almost center part of a plane at the opposite side of an information recording plane, and providing a groove preventing diffusion of stress at the plane where the clamping member of the substrate is arranged. CONSTITUTION:In an information recording area 2, a track group transferred at the time of performing injection molding, or a recording film or a reproducing reflection film is formed on a bit, and a metallic hub 3 for clamping is integrated with a hub holder 4 made of polycarbonate by insert molding, and the hub holder 4 is jointed on the substrate 1. Also, in the joint part of the hubs 3 and 4 of the substrate 1, grooves 6 are provided on the outside of the joint parts of the hubs 3 and 4, and two planes of a disk are protected by setting the information recording area inside, and are adhered by a bonding layer 7, then, an optical disk capable of using both planes can be constituted. In such a way, propagated stress generated due to the distortion of the hub metal 3 due to the difference of the coefficients of thermal expansion of the hub metal 3 and the substrate 1 is absorbed as the deformation of the groove, thereby, it is possible to suppress the double refraction of the substrate in the information recording area from being increased, and to prevent a reproducing performance from being lowered.
JP62206272A 1987-08-21 1987-08-21 Optical disk substrate Pending JPS6450250A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP62206272A JPS6450250A (en) 1987-08-21 1987-08-21 Optical disk substrate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62206272A JPS6450250A (en) 1987-08-21 1987-08-21 Optical disk substrate

Publications (1)

Publication Number Publication Date
JPS6450250A true JPS6450250A (en) 1989-02-27

Family

ID=16520578

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62206272A Pending JPS6450250A (en) 1987-08-21 1987-08-21 Optical disk substrate

Country Status (1)

Country Link
JP (1) JPS6450250A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02136476U (en) * 1989-04-13 1990-11-14
WO1997050079A1 (en) * 1996-06-26 1997-12-31 Sony Corporation Magnetic disk apparatus, magnetic disk and disk cartridge

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02136476U (en) * 1989-04-13 1990-11-14
WO1997050079A1 (en) * 1996-06-26 1997-12-31 Sony Corporation Magnetic disk apparatus, magnetic disk and disk cartridge

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