Patent US4871649A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4871649A Expired / Lapsed US ⏱️ 0.0 years remaining

Optical recording medium and optical recording method using the same

Assignee: Canon Inc
•
Filing: 1987-03-19
•
Granted: 1989-10-03
•
Expires: 2007-03-19
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract An optical recording medium wherein recording information has been recorded as pits, comprises an absorptive layer and a reflective layer placed thereon, the absorptive layer having, on the surface, concave portions thermally deformed by heat generated upon irradiation of light beams, and the reflective layer having concave pits formed by deformation as a consequence of the thermal deformation of the absorptive layer and covering said concave portions of the absorptive layer in such a state that the concave portions are not exposed. An optical recording method comprises irradiating an optical recording medium having an absorptive layer and a reflective layer placed thereon, with light beams to generate a heat, allowing the heat to cause the thermal deformation of the absortive layer to form concave portions on the surface of the absorptive layer, deforming the reflective layer as a consequence of the thermal deformation of the absorptive layer, thereby allowing the deformed reflective layer to cover the concave portions of the absorptive layer in such a state that the concave portions are not exposed and to form concave pits.

Inventors

  • 👤 Hiroyuki Imataki
  • 👤 Mizuho Hiraoka
  • 👤 Sachiko Ichikawa
  • 👤 Yoshihiro Ogawa
  • 👤 Hitoshi Yoshino

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 06:59
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/252; G11B7/258; G11B7/242; G11B7/244; G11B7/246; G11B7/2467; G11B7/247; G11B7/2472; G11B7/2475; G11B7/249; Y; Y10; Y10S; Y10S430/00; Y10S430/146; Y10S430/165

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 108 words
An optical recording method which comprises irradiating an optical recording medium having an absorptive layer and a reflective layer placed thereon, with light beams to generate heat, allowing the heat to cause the thermal deformation of the absorptive layer to form concave portions on the surface of the absorptive layer, deforming the reflective layer as a consequence of the thermally deformed concave portions of the absorptive layer, thereby allowing the deformed reflective layer to cover the concave portions of the absorptive layer such that the concave portions of the absorptive layer are not exposed and to form concave pits corresponding to the concave portions of the absorptive layer.
Claim 2
Dependent Claim 108 words
An optical recording method which comprises irradiating an optical recording medium having an absorptive layer and a reflective layer placed thereon, with light beams to generate heat, allowing the heat to cause the thermal deformation of the absorptive layer to form concave portions on the surface of the absorptive layer, deforming the reflective layer as a consequence of the thermally deformed concave portions of the absorptive layer, thereby allowing the deformed reflective layer to cover the concave portions of the absorptive layer such that the concave portions of the absorptive layer are not exposed and to form concave pits corresponding to the concave portions of the absorptive layer.
Claim 3
Dependent Claim 19 words
An optical recording method according to claim 1, wherein the reflective layer is a film formed by vapor deposition.
Claim 4
Dependent Claim 19 words
An optical recording method according to claim 1, wherein the reflective layer has a reflectivity of 10 to 185%.
Claim 5
Dependent Claim 19 words
An optical recording method according to claim 3, wherein the reflective layer has a reflectivity of 20 to 60%.
Claim 6
Dependent Claim 28 words
An optical recording method according to claim 1, wherein the absorptive layer contains a light absorbing substance selected from the group consisting of a dye or a pigment.
Claim 7
Dependent Claim 16 words
An optical recording method according to claim 1, wherein the light beams are semiconductor laser beams.

References Cited (Backward Citations)

US4176277A Cited
US4408319A Cited
US4296158A Cited
US4363844A Cited
JPS5774834A Cited
US4670332A Cited
US4629668A Cited
US4652498A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-02 1993-04-03 1993-10-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-02 1997-04-03 1997-10-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-02 2001-04-03 2001-10-03 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag