Sequential automatic registration and imagewise exposure of a sheet substrate

DETAILED DESCRIPTION The present invention is directed to a process for 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 either in order or concurrently the steps of: (a) aligning the substrate and a photomask of the sequence in a predetermined relationship to one another, (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 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.
In particular embodiments of this invention the surface of the exposed photosensitive layer may be modified by an image intensification step, e.
g.
, such as embedding image areas with a powdered toner or catalyst and/or by applying a second photosensitive layer thereto.
In yet another embodiment of this invention, both sides of the substrate contain photosensitive layers and the process steps outlined above occur simultaneously to both photosensitive layers.