초록 ▼

The present invention provides a method for reducing short time-scale reciprocity failure effects of a photosensitive imaging sheet. The photosensitive imaging sheet comprises a substrate having a layer of microcapsules on one surface thereof. The microcapsules contain an internal phase of an acryla

The present invention provides a method for reducing short time-scale reciprocity failure effects of a photosensitive imaging sheet. The photosensitive imaging sheet comprises a substrate having a layer of microcapsules on one surface thereof. The microcapsules contain an internal phase of an acrylate monomer, photoinitiator, and color former. A portion of the microcapsules of the imaging sheet is image-wise exposed to high intensity light and then allowed to recover from the exposure. The exposure and recovery steps are repeated to form a latent image. By pulsing the light onto the photosensitive imaging sheet, the total exposure energy required per unit area is significantly reduced compared to the known short time-scale exposure method.

대표청구항 ▼

A method for reducing short time-scale reciprocity failure effects of a photosensitive imaging sheet, wherein: said photosensitive imaging sheet comprises a substrate having a layer of microcapsules coated on one surface thereof, said microcapsules having an outer phase transmissive to exposure ligh

A method for reducing short time-scale reciprocity failure effects of a photosensitive imaging sheet, wherein: said photosensitive imaging sheet comprises a substrate having a layer of microcapsules coated on one surface thereof, said microcapsules having an outer phase transmissive to exposure light containing an internal phase of an acrylate monomer, photoinitiator, and color former; said imaging sheet obeying reciprocity within a range of exposure times t having a lower limit of about 10-2 seconds, such that the required exposure energy for a given exposure density is a constant value Ec such that tI=Ec, and wherein said imaging sheet exhibits short time-scale reciprocity failure below said range such that tI>Ec whereby greater energy E′is required to expose said image sheet at exposure times below said range than within said range; the method comprising the steps of: image-wise exposing a portion of said microcapsules of said imaging sheet for a time period t1 to exposure light of an intensity I; following exposure, providing a recovery period of a time tr1 for said exposed microcapsules; image-wise exposing a portion of said microcapsules of said imaging sheet for a time period t2 to exposure light of an intensity I; following exposure, providing a recovery period of a time tr2 for said exposed microcapsules; and repeating said exposure and recovery steps n times to form a latent image; said time periods t1, t2, . . . tn being selected such that E′>(t1+t2+. . . +tn)I≥Ec, and such that (t1+t2+. . . +tn) is less than about 10-2 seconds.