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US 4,522,903 AGranted
Sequential automatic registration and imagewise exposure of a sheet substrate
AssigneeE. I. Du Pont de Nemours and Company
InventorsRobert B. Heiart, Abraham B. Cohen
Life of this patent
Estimating the term…
Abstract
Method for repetitive registering and imagewise exposing to actinic radiation a sheet substrate containing a photosensitive layer with use of a sequence of related photomasks. A liquid layer separates the photosensitive layer and each photomask during the exposure step.
Claims27
A process of registering and imagewise exposing a sheet substrate containing a photosensitive layer with the use of a sequence of related photomasks comprising the steps of:
- (1) advancing the substrate containing a photosensitive layer to a position in a device to undertake in either order or concurrently the steps of:
- (a) aligning the substrate and a photomask of the sequence in a predetermined relationship to one another through a hinged relationship of the photomask and the substrate to permit substantially identical alignment of the substrate and each photomask of the sequence;
- (b) applying a liquid between the photosensitive layer and the photomask;
- (2) contacting through the liquid the substrate containing the photosensitive layer and the photomask wherein liquid between the photosensitive layer and the photomask is displaced when the substrate and photomask are brought into more intimate contact by an advancing pressure line whereby during said contacting substantially no movement of the photosensitive layer relative to the photomask occurs other than a more intimate contact due to displacement of the liquid in a liquid layer whereby at least one of interfacial or viscous force due to the liquid layer aids in holding the photosensitive layer and photomask in a fixed position relative to one another;
- (3) exposing the photosensitive layer to actinic radiation through said photomask, causing an image to be formed thereon;
- (4) removing the photomask from the exposed photosensitive layer;
- (5) modifying the surface of the exposed photosensitive layer;
- (6) repeating steps 1 to 5 for each of the remaining photomasks of said sequence.
5 more elements
A process of registering and imagewise exposing a sheet substrate containing a photosensitive layer with a sequence of related photomasks in making a four-color surprint comprising the steps of:
- (1) advancing the substrate containing a first photosensitive layer to a position in a device to undertake either in order or concurrently the steps of:
- (a) aligning the substrate and a first photomask of the sequence in a predetermined relationship to one another through a hinged relationship of the photomask and the substrate to permit substantially identical alignment of the substrate and each photomask of the sequence;
- (b) applying a liquid between the substrate containing the photosensitive layer and the photomask;
- (2) contacting through the liquid the substrate containing the photosensitive layer and the photomask wherein liquid between the photosensitive layer and the photomask is displaced when the substrate and photomask are brought into more intimate contact by an advancing pressure line, whereby during said contacting substantially no movement of the photosensitive layer relative to the photomask occurs other than a more intimate contact due to displacement of the liquid in a liquid layer whereby at least one of interfacial or viscous force due to the liquid layer aids in holding the photosensitive layer and photomask in a fixed position relative to one another;
- (3) exposing the photosensitive layer to actinic radiation through said photomask, causing an adherent image to be formed on the substrate;
- (4) removing the photomask from the exposed photosensitive layer;
- (5) developing the adherent image on the substrate by application of a particulate colorant;
- (6) applying a further photosensitive layer to the exposed substrate whereby steps 1 to 5 can be repeated with a further photomask of said sequence;
- and
- (7) repeating steps 1 to 6 for each of the remaining photomasks of said sequence;
- whereby a four-color surprint is obtained;
- provided, however, step (6) need not be employed with use of the last photomask.
9 more elements
Dependencies are inferred from the claim text.