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US4931313A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming a protective film for an optical recording medium

Assignee: Sony Corp
•
Filing: 1988-08-31
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Granted: 1990-06-05
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Expires: 2008-08-31
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Abstract

Abstract A method of forming a protective film (14) for an optical recording medium such as a compact disc (16). A protective film forming ink (22) having a viscosity in the range between 0.09 and 10 Pa.s is applied to a surface of a pad (21) having a Shore A hardness between 8 and 30. The spherical surface of the pad (21) thus loaded with the ink (22) is pressed against a substrate (11) of the optical recording medium on which a reflective layer (13) has been formed, to transfer the protective film forming ink (22) to the surface of the substrate (11). The ink (22) is then cured to form the protective film (14) over the entire surface of the reflective layer (13).

Inventors

  • 👤 Nobuyuki Arakawa
  • 👤 Hirotsugu Suzuki
  • 👤 Tokihiro Nishihara

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-01 18:10
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/257; G11B7/2572; G11B7/2575; G11B7/254; G11B7/2542; G11B7/242; G11B7/243; G11B2007/24302; G11B2007/2431

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 87 words
A method of forming a protected optical recording medium having a recording layer on a substrate comprising steps of: applying a protective film forming ink having a viscosity in a range of 0.9 to 100 poise to a pad having a Shore A hardness in a range of 8 to 30; and pressing the pad against the recording layer on the substrate to transfer the protective film forming ink to the recording layer in a protective film that extends over the peripheral edges of the recording layer.
Claim 2
Independent Claim 87 words
A method of forming a protected optical recording medium having a recording layer on a substrate comprising steps of: applying a protective film forming ink having a viscosity in a range of 0.9 to 100 poise to a pad having a Shore A hardness in a range of 8 to 30; and pressing the pad against the recording layer on the substrate to transfer the protective film forming ink to the recording layer in a protective film that extends over the peripheral edges of the recording layer.
Claim 3
Dependent Claim 21 words
A method according to claim 1, further comprising a step to cure said protective film forming ink on said recording layer.
Claim 4
Dependent Claim 23 words
A method according to claim 1, wherein said protective film forming ink has a viscosity in a range between 30 and 80 poise.
Claim 5
Dependent Claim 23 words
A method according to claim 1, said pad has a spindle-shape rotationally symmetric with respect to a center axis, or a semispherical shape.
Claim 6
Dependent Claim 46 words
A method according to claim 4, wherein said optical recording medium substrate is rotatable about the central axis perpendicular to the plane of the substrate and said pad is pressed against said substrate so that said center axis coincides with the central axis of said substrate.

References Cited (Backward Citations)

DE2653831A1 Cited
US4479432A Cited
JPS58137146A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-04 1993-12-04 1994-06-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-06-04 1997-12-04 1998-06-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-06-04 2001-12-04 2002-06-05 $7700.00 Window Closed / Lapsed

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