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US4940618A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical information recording medium

Assignee: Taiyo Yuden Co Ltd
•
Filing: 1989-04-14
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Granted: 1990-07-10
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Expires: 2009-04-14
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Abstract

Abstract An optical information recording medium of the type wherein recorded data signals are reproduced by scanning them with a laser beam. The medium comprises a ROM region where optically readable pits are already formed and an information recordable region where optically readable pits can be formed by irradiation with a writing laser beam. The infomation recordable region comprises a light transmitting substrate having a deformable surface, a light absorptive layer overlaying the deformable surface, which absorbs the writing laser beam, and a light reflective layer overlaying the light absorptive layer. The deformable surface is deformable by energy generated upon absorption of the writing laser beam by the light absorptive layer, to thereby form optically readable pits.

Inventors

  • 👤 Emiko Hamada
  • 👤 Yuji Arai
  • 👤 Yuaki Shin
  • 👤 Takashi Ishiguro

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 06:14
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/24018; G11B7/24027; G11B7/007; G11B7/0079; G11B7/241; G11B7/004; G11B7/0045; G11B7/00452; G11B7/005; G11B7/0051; Y; Y10; Y10S; Y10S428/00; Y10S428/913; Y10S430/00; Y10S430/146; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/31504; Y10T428/31678

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 114 words
An optical information recording medium of the type wherein recorded data are reproduced by scanning them with a laser beam, which comprises a ROM region where optically readable pits are already formed and an information recordable region where optically readable pits can be formed by irradiation with a writing laser beam, wherein the information recordable region comprises a light transmitting substrate having a deformable surface, a light absorptive layer overlaying the deformable surface, to absorb the writing laser beam, and a light reflective layer overlaying the light absorptive layer, said deformable surface being deformable by energy generated upon absorption of the writing laser beam by the light absorptive layer, to form optically readable pits.
Claim 2
Dependent Claim 114 words
An optical information recording medium of the type wherein recorded data are reproduced by scanning them with a laser beam, which comprises a ROM region where optically readable pits are already formed and an information recordable region where optically readable pits can be formed by irradiation with a writing laser beam, wherein the information recordable region comprises a light transmitting substrate having a deformable surface, a light absorptive layer overlaying the deformable surface, to absorb the writing laser beam, and a light reflective layer overlaying the light absorptive layer, said deformable surface being deformable by energy generated upon absorption of the writing laser beam by the light absorptive layer, to form optically readable pits.
Claim 3
Dependent Claim 43 words
The optical information recording medium according to claim 1, wherein the light transmitting substrate has a heat distortion temperature within a range of from 85° to 200° C. as measured in accordance with ASTM D648 under a load of 4.6 kg/cm 2 .
Claim 4
Dependent Claim 33 words
The optical information recording medium according to claim 1, wherein the light transmitting substrate has a Rockwell hardness within a range of from M200 to M75 as measured in accordance with ASTM D785.
Claim 5
Dependent Claim 27 words
The optical information recording medium according to claim 1, wherein the light transmitting substrate is made of a polycarbonate resin, an acrylate resin or an epoxy resin.
Claim 6
Dependent Claim 18 words
The optical information recording medium according to claim 1, wherein the light absorptive layer contains a cyanine dye.
Claim 7
Dependent Claim 24 words
The optical information recording medium according to claim 1, wherein the reflective layer is made of gold, silver, copper, aluminum or an alloy thereof.
Claim 8
Dependent Claim 34 words
The optical information recording medium according to claim 1, wherein the deformable surface layer of the light transmitting substrate has a tracking guide groove in which said optically readable pits are to be formed.
Claim 9
Dependent Claim 19 words
The optical information recording medium according to claim 1, wherein a protective layer is provided as a top layer.

References Cited (Backward Citations)

US4315269A Cited
US4404656A Cited
US4405994A Cited
US4577291A Cited
US4586165A Cited
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GB2079031A Cited
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EP0103892A2 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-07-09 1994-01-08 1994-07-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-07-09 1998-01-08 1998-07-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-07-09 2002-01-08 2002-07-10 $7700.00 Window Closed / Lapsed

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