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EP0818782A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Methods for providing artwork on plastic information discs

Assignee: Wea Manufacturing Inc
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Filing: 1997-07-04
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Granted: —
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Expires: 2017-07-04
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Abstract

Abstract Artwork is imparted to plastic discs such as CDs, CD ROMs, and DVDs (digital video discs) by exposing a layer of photoresist material on a substrate to light from an original image of the artwork. The material of the photoresist layer is exposed to different depths by different intensity light from different image regions. Where the image is dark, the exposure is to relatively shallow, random depths. Where the image is light, the full thickness of the photoresist layer is exposed. Development of the photoresist layer removes the exposed photoresist material. The surface features of the developed photoresist layer and any uncovered substrate are transferred to a member used in forming a surface of the plastic disc, thereby visibly embossing the image in the disc.

Inventors

  • 👤 Peter Van Hoof
  • 👤 John Joseph Parette
  • 👤 John F. Pierzga

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-02 23:09
CPC Classifications
G; G03; G03F; G03F7/00; G11; G11B; G11B23/00; G11B23/38; G11B23/40; G11B7/00; G11B7/24; G11B7/26; G11B7/261; B; B29; B29L; B29L2017/00; B29L2017/001; B29L2017/003; B29L2031/00; B29L2031/722; Y; Y10; Y10T; Y10T428/00; Y10T428/21

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 132 words
A method of forming a visible image on a major surface of a substantially planar plastic disc comprising the steps of:- providing a layer of photoresist material on a substrate; providing a representation of said visible image on a medium in which said visible image is represented by different degrees of opacity of different portions of said medium; shining light through said medium onto said layer in order to expose said layer to different depths in different regions indicative of the opacity of the portion of the medium associated with each region; removing exposed photoresist material from said layer; forming an impression of what remains of said layer and any uncovered substrate in a forming member; and using said forming member to make an impression in said major surface of said disc.
Claim 2
Dependent Claim 27 words
The method defined in Claim 1 further comprising the step of exposing the photoresist layer to light through a diffusion sheet prior to performing said shining step.
Claim 3
Dependent Claim 26 words
The method defined in Claim 1 further comprising the step of exposing the photoresist layer to light through a diffusion sheet after performing said shining step.
Claim 4
Dependent Claim 17 words
The method defined in Claim 1,2 or 3 wherein said layer is initially approximately 1 micron thick.
Claim 5
Independent Claim 64 words
The method defined in any preceding Claim wherein in said shining step said layer is exposed all the way through to said substrate surface in some but not all of said regions of said layer, so that in said forming step the impression formed includes an impression of said substrate surface where said layer was exposed all the way through to said substrate surface.
Claim 6
Dependent Claim 13 words
The method defined in Claim 5 wherein said substrate surface is substantially smooth.
Claim 7
Dependent Claim 12 words
The method defined in Claim 5 wherein said substrate surface is roughened.
Claim 8
Dependent Claim 28 words
The method defined in Claim 7 wherein the maximum depth of roughening of said substrate surface is in the range from about 300 nanometers to about 1000 nanometers.
Claim 9
Dependent Claim 44 words
The method defined in Claim 7 or 8 wherein said step of providing a layer of photoresist material on a substrate comprises the step of:- covering said substrate surface with a thickness of photoresist material substantially greater than the maximum depth of said roughening.
Claim 10
Dependent Claim 24 words
The method defined in Claim 9 wherein said thickness of photoresist material is in the range from about 300 nanometers to about 1000 nanometers.
Claim 11
Dependent Claim 19 words
The method defined in Claim 7,8,9 or 10 wherein said substrate surface is roughened by sand blasting that surface.
Claim 12
Dependent Claim 19 words
The method defined in Claim 7,8,9 or 10 wherein said substrate surface is roughened by chemically etching that surface.
Claim 13
Independent Claim 27 words
The method defined in any preceding Claim wherein said medium is a transparency, and wherein prior to said shining step said transparency is placed on said layer.
Claim 14
Independent Claim 18 words
The method defined in any preceding Claim wherein said representation of said visible image includes half-tone image information.
Claim 15
Independent Claim 22 words
The method defined in any preceding Claim wherein said removing step comprises the step of:- placing said layer in photoresist developer solution.
Claim 16
Independent Claim 36 words
The method defined in any preceding Claim wherein said forming step comprises the steps of:- coating what remains of said layer and any uncovered substrate with metal; and separating said metal from said layer and substrate.
Claim 17
Dependent Claim 52 words
The method defined in Claim 16 wherein said coating step comprises the steps of:- exposing said layer and uncovered substrate to a vapour of said metal so that metal condenses on said layer and uncovered substrate; and plating additional metal on the metal that has condensed on said layer and uncovered substrate.
Claim 18
Dependent Claim 34 words
The method defined in Claim 16 or 17 wherein said forming step further comprises the step of:- using the metal separated from said layer and substrate as a master for making said forming member.
Claim 19
Dependent Claim 55 words
The method defined in Claim 18 wherein said step of using the metal comprises the steps of:- removably depositing additional metal on said master; separating said additional metal from said master to produce an intermediary; removably depositing further metal on said intermediary; and separating said further metal from said intermediary to produce said forming member.
Claim 20
Independent Claim 31 words
The method defined in any preceding Claim wherein said using step comprises the step of: employing said forming member as a surface of a mould in which said disc is moulded.
Claim 21
Dependent Claim 14 words
A plastic disc made by the method of any of Claims 1 to 20.

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