EP0103892A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Optical recording medium and method of making same
Assignee: Discovision Associates
•
Filing: 1983-09-20
•
Granted: —
•
Expires: 2003-09-20
Abstract
Abstract An optical recording medium for use with a recording apparatus of the type that focuses onto the medium, as the medium is moved in a prescribed fashion, a beam of light that is modulated in intensity in accordance with a data signal to be recorded. The recording medium includes a substrate having a smooth, planar upper surface, with a thin light-absorbing coating overlaying the surface, such coating including an explosive material such as nitrocellulose, and a light-absorbing dye. As the medium is moved with respect to the intensity-modulated beam, the explosive coating is selectively energized by the beam to induce spaced explosions therein, whereby corresponding optically readable irregularities, representative of the data signal, are formed in the outer surface of the coating. A light-reflecting material is then deposited over the coating containing the surface irregularities, and, if desirable, a plastic protective layer is deposited over the light-reflecting layer. Two of such mediums can be bonded back-to-back to form a two-sided record.
Inventors
- 👤 Richard L. Wilkinson
- 👤 Gary G. Slaten
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 11:12
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B7/241; G11B7/242; G11B7/004; G11B7/0045; G11B7/00451; G11B7/244; G11B7/26; G11B7/245; G11B7/252; G11B7/254; G11B7/2542; G11B7/258
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
144 words
A recording medium for use in a recording apparatus wherein a beam of light, having a prescribed intensity that varies in accordance with a data signal to be recorded, is directed at the medium as the medium is moved with respect thereto, said medium comprising: a substrate having an upper surface; a light-absorbing layer overlaying the upper surface of said substrate, said light-absorbing layer including an explosive material, wherein as the medium is moved with respect to the intensity-modulated writing beam, said layer is selectively energized by the beam to induce spaced explosions therein, whereby sufficient energy from the intensity-modulated beam of light is absorbed by said layer that the selected portions thereof on which the beam impinges are exploded completely, yielding.pits in at least the outer surface of said layer, representative of the data signal; and a light-reflective layer overlaying said light-absorbing layer.
Claim 2
Dependent Claim
144 words
A recording medium for use in a recording apparatus wherein a beam of light, having a prescribed intensity that varies in accordance with a data signal to be recorded, is directed at the medium as the medium is moved with respect thereto, said medium comprising: a substrate having an upper surface; a light-absorbing layer overlaying the upper surface of said substrate, said light-absorbing layer including an explosive material, wherein as the medium is moved with respect to the intensity-modulated writing beam, said layer is selectively energized by the beam to induce spaced explosions therein, whereby sufficient energy from the intensity-modulated beam of light is absorbed by said layer that the selected portions thereof on which the beam impinges are exploded completely, yielding.pits in at least the outer surface of said layer, representative of the data signal; and a light-reflective layer overlaying said light-absorbing layer.
Claim 3
Dependent Claim
23 words
A recording medium as defined in Claim 1, wherein the pits formed in said light-absorbing layer extend completely therethrough, exposing the substrate thereunder.
Claim 4
Dependent Claim
44 words
A recording medium as defined in Claim 1, wherein said light-absorbing layer further includes a dye material in solution with the explosive material, said dye material adapted to absorb the intensity-modulated beam of light and thereby heat the light-absorbing layer by a prescribed amount.
Claim 5
Dependent Claim
39 words
A recording medium as defined in Claim 1, wherein: said substrate is formed of polymethylmethacrylate in the shape of a disc and substantially transparent to the reading beam of a player apparatus used to retrieve the recorded data signal.
Claim 6
Dependent Claim
28 words
A recording medium as defined in Claim 4, including a protective layer of plastic material overlaying said light-reflective layer to protect the light-reflective layer from dust and abrasion.
Claim 7
Dependent Claim
14 words
A recording medium as defined in Claim 1, wherein said explosive material comprises nitrocellulose.
Claim 8
Dependent Claim
14 words
A recording medium as defined in Claim 1, wherein said explosive material comprises trinitroaniline.
Claim 9
Dependent Claim
14 words
A recording medium as defined in Claim 1, wherein said explosive material comprises trinitrotoluene.
Claim 10
Dependent Claim
112 words
A recording medium as defined in Claim 4, including: a second disc-shaped substrate; a second selectively energized light-absorbing layer overlaying said second substrate, said second light-absorbing layer including an explosive material; a second light-reflective layer overlaying said second light-absorbing layer; both said first substrate and said second substrate being transparent to the reading beam of a player apparatus used to retrieve the recorded data signal; a second protective layer of plastic material overlaying said second light-reflective layer; and an adhesive layer bonding said two protective ∞ layers together to produce a two-sided record disc, whereby the read beam can be selectively transmitted through either substrate to impinge on its corresponding overlaying coating.
Claim 11
Independent Claim
138 words
A method of recording a data signal on a movable recording medium of the type having a substrate and a light-absorbing coating overlaying the substrate, said coating including an explosive material, said method comprising the steps of: moving the recording medium in a prescribed fashion; modulating the intensity of a write beam of light in accordance with the data signal to be recorded; directing the intensity-modulated write beam of light onto the medium as the medium is moved with respect thereto, said beam having a peak intensity selected such that the coating is selectively energized by the beam to induce spaced explosions therein, whereby corresponding irregularities, representative of the data signal, are formed in the outer surface of the coating; and overlaying the surface of said coating having said irregularities formed therein with a layer of light-reflecting material:
Claim 12
Independent Claim
138 words
A method of recording a data signal on a movable recording medium of the type having a substrate and a light-absorbing coating overlaying the substrate, said coating including an explosive material, said method comprising the steps of: moving the recording medium in a prescribed fashion; modulating the intensity of a write beam of light in accordance with the data signal to be recorded; directing the intensity-modulated write beam of light onto the medium as the medium is moved with respect thereto, said beam having a peak intensity selected such that the coating is selectively energized by the beam to induce spaced explosions therein, whereby corresponding irregularities, representative of the data signal, are formed in the outer surface of the coating; and overlaying the surface of said coating having said irregularities formed therein with a layer of light-reflecting material:
Claim 13
Dependent Claim
52 words
A method as defined in Claim 10, wherein the peak intensity of the intensity-modulated write beam of light is sufficient to induce complete explosions in the selected portions of the coating on which the beam impinges, yielding pits in at least the outer surface of the coating, representative of the data signal.
Claim 14
Dependent Claim
48 words
A method as defined in Claim 10, wherein the peak intensity of the intensity-modulated write beam of light is sufficient to induce only partial explosions in the selected portions of the coating on which the beam impinges, yielding upraised bumps in the coating, representative of the data signal.
Claim 15
Independent Claim
136 words
A method of producing a recording medium having in information containing layer with surface irregularities representing recorded data signals, said method comprising the steps of: depositing on a smooth, planar surface of a substrate a coating that includes an explosive material; moving the coated substrate in a prescribed fashion relative to a beam of light that is modulated in intensity in accordance with the data signal to be recorded in the coating, said coating being-selectively heated by the beam to induce spaced explosions therein, to form corresponding irregularities in the outer surface of the coating representative of the data signal, said irregularities being formed without the need for a separate step of chemically developing the coating; and depositing an outer layer of light-reflective material on the coated substrate, after the surface irregularities have been formed therein.
Claim 16
Independent Claim
136 words
A method of producing a recording medium having in information containing layer with surface irregularities representing recorded data signals, said method comprising the steps of: depositing on a smooth, planar surface of a substrate a coating that includes an explosive material; moving the coated substrate in a prescribed fashion relative to a beam of light that is modulated in intensity in accordance with the data signal to be recorded in the coating, said coating being-selectively heated by the beam to induce spaced explosions therein, to form corresponding irregularities in the outer surface of the coating representative of the data signal, said irregularities being formed without the need for a separate step of chemically developing the coating; and depositing an outer layer of light-reflective material on the coated substrate, after the surface irregularities have been formed therein.
Claim 17
Dependent Claim
42 words
A method as defined in Claim 13 wherein: said substrate includes a polymethylmethacrylate material; and said last-mentioned depositing step includes the step of vacuum depositing, on the outer surface of the coating containing said surface irregularities, an outer layer of metallic material.
Claim 18
Dependent Claim
14 words
A method as defined in Claim 14 wherein: said outer metallic layer is aluminum.
Claim 19
Dependent Claim
97 words
A method as defined in Claim 13, wherein said step of depositing the coating that includes an explosive material includes the steps of: depositing onto the substrate a liquid solution that includes the explosive material and a solvent; spinning the substrate at a first prescribed angular velocity until the liquid solution has achieved a substantially uniform thickness over the entire planar surface of the substrate; and spinning the substrate at a second prescribed angular velocity until the solvent in the liquid solution is substantially completely evaporated, leaving the coating deposited on the planar surface of the substrate.
Claim 20
Dependent Claim
29 words
A method as defined in Claim 13, including the step of: depositing a protective plastic layer over said light-reflective layer to protect the light-reflective layer from dust and abrasion.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.