EP0818782A2
Expired / Lapsed
EP
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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
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 14:15
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.
References Cited (Backward Citations)
No citation records indexed.
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