Patent EP0167352A2 successfully refreshed from Google Patents.
EP0167352A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Imaging method, apparatus, and product
Assignee: Milliken Research Corp
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Filing: 1985-06-26
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Granted: —
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Expires: 2005-06-26
Abstract
Abstract A method for generating a latent image on a substrate surface using a low current (e.g., less than about 2x10 -3 amperes), non-pulsating electrical discharge. The method may be used, for example, to image lithographic plates, with a resolution of approximately 1,000 lines/inch, directly from a digital source of image data. The discharge is confined within a thin stream of a relatively inert gas (48) which is directed at the plate surface (20) with a velocity of at least about Mach 0.05.
Inventors
- 👤 Michael William Gilpatrick
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 20:23
CPC Classifications
B; B41; B41C; B41C1/00; B41C1/10; B41C1/1041; B41C1/1075
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
107 words
A process for creating a desired latent image on an unimaged, electrically conductive substrate surface, said surface carrying an unimaged material thereon, said material being capable of being insolubilized when acted upon by a low current non-pulsating electrical discharge to form a latent image thereon whch thereafter may be developed for use in a printing process by conventional lithographic-type developing processes, comprising contacting areas of said material on said surface corresponding to said image with a low current localized-type electrical discharge, said discharge being of sufficient energy density to insolubilize, with respect to conventional lithographic-type developing materials, said material only in said areas contacted by said discharge.
Claim 2
Dependent Claim
107 words
A process for creating a desired latent image on an unimaged, electrically conductive substrate surface, said surface carrying an unimaged material thereon, said material being capable of being insolubilized when acted upon by a low current non-pulsating electrical discharge to form a latent image thereon whch thereafter may be developed for use in a printing process by conventional lithographic-type developing processes, comprising contacting areas of said material on said surface corresponding to said image with a low current localized-type electrical discharge, said discharge being of sufficient energy density to insolubilize, with respect to conventional lithographic-type developing materials, said material only in said areas contacted by said discharge.
Claim 3
Dependent Claim
35 words
The process of claim 1 wherein said electrical discharge is substantially coaxial with a stream of a relatively inert gas directed at said substrate surface at a subsonic velocity of at least about Mach 0.05.
Claim 4
Dependent Claim
136 words
A process for creating a latent image on an unimaged printing plate, said plate having an unimaged coating thereon in which an insolubilizing effect may be induced by a low current localized type electrical discharge, comprising the steps of: (a) positioning an electrode in close proximity to the coated surface of said plate thereby forming a discharge gap; (b) directing a relatively inert gas into said gap in the direction of said plate surface in the form of a thin, well-defined stream having a velocity of at least about Mach 0.05; (c) initiating a low current localized-type electrical discharge between said electrode and said plate surface, within said gas stream, and (d) maintaining the time-averaged current flow within said discharge to a value sufficient to induce an insolubilizing effect in said coating contacted by said discharge.
Claim 5
Dependent Claim
136 words
A process for creating a latent image on an unimaged printing plate, said plate having an unimaged coating thereon in which an insolubilizing effect may be induced by a low current localized type electrical discharge, comprising the steps of: (a) positioning an electrode in close proximity to the coated surface of said plate thereby forming a discharge gap; (b) directing a relatively inert gas into said gap in the direction of said plate surface in the form of a thin, well-defined stream having a velocity of at least about Mach 0.05; (c) initiating a low current localized-type electrical discharge between said electrode and said plate surface, within said gas stream, and (d) maintaining the time-averaged current flow within said discharge to a value sufficient to induce an insolubilizing effect in said coating contacted by said discharge.
Claim 6
Dependent Claim
26 words
The process of claim 3 wherein said value of the time-averaged current flow within said discharge gap is between about 2x10-6 and about 2x10 -3 amperes.
Claim 7
Dependent Claim
13 words
The process of claim 3 wherein the voltage across said gap is non-pulsating.
Claim 8
Dependent Claim
23 words
The process of claim 3 wherein said gas stream has a minimum transverse cross-sectional area of less than about 2x10 -5 square inches.
Claim 9
Dependent Claim
25 words
The product of the process of claim 6, wherein the resulting latent image has a minimum uniform dot diameter of less than about 0.004 inch.
Claim 10
Dependent Claim
18 words
The process of claim 3, wherein said gas stream is directed from an aperture associated with said electrode.
Claim 11
Dependent Claim
21 words
The process of claim 3, wherein said electrode is a tube, and said gas stream is directed from the tube bore.
Claim 12
Dependent Claim
32 words
The method of claim 3 wherein said current flow is limited to a maximum value which is insufficient to displace said coating so as to substantially expose said plate under said coating.
Claim 13
Dependent Claim
49 words
The method of claim 3 wherein said electrode is scanned over said plate surface by means of relative movement between said electrode and said plate surface, and said localized-type discharge is maintained only while said electrode is opposite areas of said plate surface wherein said insolubilizing effect is desired.
Claim 14
Dependent Claim
23 words
The method of claim 11 wherein said diffuse-type discharge is maintained at times other than those when said localized-type discharge is being maintained.
Claim 15
Dependent Claim
19 words
The method of claim 3 wherein the current flow in said discharge is modulated in accordance with pattern information.
Claim 16
Independent Claim
141 words
An apparatus for creating a latent image on an unimaged printing plate, said plate having an unimaged coating thereon in which an insolubilizing effect may be induced by a low current localized-type electrical discharge, comprising: (a) means for positioning an electrode in close proximity to the coated surface of said plate thereby forming a discharge gap; (b) means for directing a relatively inert gas into said gap in the direction of said plate surface in the form of a thin, well-defined stream having a subsonic velocity of at least about Mach 0.05; (c) means for initiating a low current localized-type electrical discharge between said electrode and said plate surface, within said gas stream, and (d) means for maintaining the time-averaged current flow within said discharge to a value sufficient to induce an insolubilizing effect in said coating contacted by said discharge.
Claim 17
Independent Claim
141 words
An apparatus for creating a latent image on an unimaged printing plate, said plate having an unimaged coating thereon in which an insolubilizing effect may be induced by a low current localized-type electrical discharge, comprising: (a) means for positioning an electrode in close proximity to the coated surface of said plate thereby forming a discharge gap; (b) means for directing a relatively inert gas into said gap in the direction of said plate surface in the form of a thin, well-defined stream having a subsonic velocity of at least about Mach 0.05; (c) means for initiating a low current localized-type electrical discharge between said electrode and said plate surface, within said gas stream, and (d) means for maintaining the time-averaged current flow within said discharge to a value sufficient to induce an insolubilizing effect in said coating contacted by said discharge.
Claim 18
Dependent Claim
23 words
The apparatus of claim 14 which further includes means for varying the time-averaged current flow within said discharge in accordance with pattern information.
Claim 19
Dependent Claim
20 words
The apparatus of claim 14 wherein said means for positioning said electrode may be controlled in accordance with pattern information.
Claim 20
Dependent Claim
31 words
The apparatus of claim 14 wherein said electrode comprises a hollow stylus having a longitudinal bore and wherein said means for directing said gas into said gap comprises said stylus bore.
Claim 21
Dependent Claim
17 words
The apparatus of claim 17 wherein said stylus bore has a maximum diameter of about 0.004 inch.
References Cited (Backward Citations)
No citation records indexed.
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