Methods and apparatus for rendering an optically encoded medium unreadable
First Claim
1. A method for intentionally making an optically readable media unreadable by a play process, comprising steps of:
- providing the media with an optically activated mechanism that degrades the reflectivity of a surface wherein information is encoded;
exposing the media to optical radiation for reading out the information; and
during the step of exposing, initiating the operation of the optically activated mechanism;
wherein the step of initiating comprises steps of, generating singlet oxygen in a photoresponsive layer disposed on the media;
diffusing the singlet oxygen through a diffusion barrier that is disposed between the photoresponsive layer and a metal-containing layer; and
reacting the singlet oxygen with the metal-containing layer for oxidizing the surface of the metal-containing layer, thereby degrading the reflectivity of the surface.
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Accused Products
Abstract
Methods and apparatus are provided for making an optically readable media unreadable. The method includes steps of (a) providing the media with an optically activated mechanism that degrades the reflectivity of a surface wherein information is encoded; (b) exposing the media to optical radiation for reading out the information; and, during the step of exposing, (c) initiating the operation of the optically activated mechanism. In this embodiment the step of initiating includes steps of (d) generating singlet oxygen in a layer disposed on the media; and (e) reacting the singlet oxygen with a metal-containing layer for oxidizing the surface of the metal-containing layer, thereby degrading the reflectivity of the surface. In a further aspect the optically activated mechanism causes a defocusing of a readout beam, thereby degrading reflection of the readout beam from a surface wherein information is encoded. In another embodiment the method deforms a surface of the layer resulting in readout beam aberration or in an inability to correctly stay on track. In another embodiment a portion of the surface is removed to the atmosphere, such as by evaporation of sublimation. In this embodiment a layer of the media is comprised of a volatile component and at least one other component. Removing at least some of volatile component by evaporation or sublimation causes an increase in at least one of photoabsorption or scattering or surface roughness with the remaining component, thereby rendering at least a portion of encoded information of the media unreadable, or affecting the tracking operation.
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Citations
11 Claims
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1. A method for intentionally making an optically readable media unreadable by a play process, comprising steps of:
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providing the media with an optically activated mechanism that degrades the reflectivity of a surface wherein information is encoded;
exposing the media to optical radiation for reading out the information; and
during the step of exposing, initiating the operation of the optically activated mechanism;
wherein the step of initiating comprises steps of, generating singlet oxygen in a photoresponsive layer disposed on the media;
diffusing the singlet oxygen through a diffusion barrier that is disposed between the photoresponsive layer and a metal-containing layer; and
reacting the singlet oxygen with the metal-containing layer for oxidizing the surface of the metal-containing layer, thereby degrading the reflectivity of the surface.
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2. A method for intentionally making an optically readable media permanently unreadable by a play process, comprising the steps of:
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providing an optically readable media with an optically activated mechanism, said optically activated mechanism interferes with the ability of the play process to read at least a portion of a data encoded reflective layer on said optically readable media, exposing the optically readable media to optical radiation for reading out information on said optically readable media, said information encoded on said data encoded reflective layer; and
during the step of exposing, initiating the operation of the optically activated mechanism, wherein the step of initiating comprises;
generating an optically intensity gradient in a layer disposed on the optically readable media, wherein said layer comprises a first surface and a second surface, said first surface is unconstrained; and
in response to the generated optical intensity gradient, deforming said first surface of the layer, said first surface deformation making said at least a portion of said data encoded reflective layer unreadable by the play process.- View Dependent Claims (3, 4)
irradiating a photocurable polymer region that comprises the media; and
in response to the irradiation, photopolymerizing the polymer, thereby changing an index of refraction of the polymer resulting in readout beam aberration.
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5. An optically readable media capable of intentionally being made unreadable by a play process, said media comprising
an optically activated mechanism that is responsive to light used to readout information for degrading the reflectivity of a surface wherein the information is encoded, wherein said mechanism is comprised of a photosenistizer compound for reacting with oxygen molecules that are present within a second layer for generating singlet oxygen in the second layer, the singlet oxygen reacting with said data encoded reflective layer for oxidizing the surface of said data encoded reflective layer, thereby degrading the reflectivity of the surface of said data encoded reflective layer.
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6. An optically readable media capable of intentionally being made unreadable by a play process, said media comprising an optically activated mechanism that is responsive to light used to readout information for degrading the reflectivity of a surface wherein the information is encoded, wherein said mechanism is comprised of a photosensitizer compound for reacting with oxygen molecules that are present within a layer for generating singlet oxygen in the layer, the singlet oxygen reacting with a metal-containing layer for oxidizing the surface of the metal-containing layer, thereby degrading the reflectivity of the surface;
- the optically readable media further comprising a diffusion barrier disposed between said layer and said metal-containing layer.
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7. An optically readable media capable of intentionally being made permanently unreadable by a play process, said media comprising:
an optically activated mechanism that is responsive to light used to readout information from a data encoded reflective layer, said optically activated mechanism defocuses a readout beam, thereby making at least a portion of said data encoded reflective layer unreadable by said readout beam, wherein said optically activated mechanism is comprised of a layer of polymer that is responsive to an optical intensity gradient generated by said readout beam for deforming an unconstrained surface of said layer, resulting in readout beam aberration. - View Dependent Claims (8, 9)
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10. A method for intentionally making an optically readable media permanently unreadable, comprising steps of:
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providing an optically readable media with a data encoded reflective layer, said data encoded reflective layer readable by a readout beam;
providing the optically readable media with a surface layer having a planar surface topography, said surface layer preceding said data encoded reflective layer in the optical path of the readout beam; and
subsequent to or during a first readout of the optically readable media, modifying at least a portion of the planar surface topography to non-planar surface topography by the use of a photresponsive polymer and an optical intensity gradient that interacts with the photresponsive polymer for modifying the planar surface topography to the non-planar surface topography, wherein a deviation of the non-planar surface layer topography from the planar surface layer topography is sufficient to detrimentally affect at least a tracking operation of a readout device that generates the readout beam.
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11. A method for making a limited play optically readable media, said method comprising the steps of:
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providing an optically readable media with a data encoded reflective layer, said data encoded reflective layer readable by an optically readable media reading device, said optically readable media reading device comprising a reading beam;
providing an optically readable media with an optically activated mechanism, said optically activated mechanism comprising a layer with a first surface and a second surface, wherein said first surface is unconstrained, said layer preceding said data encoded reflective layer in the optical path of the reading beam of the optically readable media reading device;
wherein said optically activated mechanism deforms said first surface of said layer in response to said reading beam of said optically readable media reading device, said deformation inhibits the ability of said reading device to read at least a portion of said data encoded reflective layer on said optically readable media.
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Specification