Process for the production of projection transparencies

Claim 1

A PROCESS FOR THE PRODUCTION OF PROJECTION TRANSPARENCIES AND THE LIKE FROM A GRAPHIC SUBJECT HAVING A SURFACE CONTAINING INFRARED ABSORBENT IMAGE AREAS AND BACKGROUND AREAS HAVING RELATIVELY NON-INFRARED ABSORBENT PROPERTIES, THE STEPS COMPRISING APPLYING A SUBSTANTIALLY UNIFORM STRATUM OF A SUBSTANTIALLY COLORLESS SUBLIMEABLE MATERIAL ONTO SAID SURFACE BY UTILIZING A CHARGING SHEET, SAID CHARGING SHEET HAVING ON ONE SIDE THEREOF A COATING OF A SUBLIMEABLE MATERIAL AND AN INFRARED ABSORBING SURFACE ON THE OTHER SIDE THEREOF, PLACING SAID ONE SIDE OF SAID CHARGING SHEET IN CONTACT WITH SAID SURFACE OF SAID SUBJECT, AND EXPOSING SAID SHEET AND SUBJECT TO INFRARED RADIATION FOR A TIME SUFFICIENT TO CAUSE SUBLIMATION OF SUBLIMEABLE MATERIAL FROM SAID CHARGING SHEET ONTO SAID SURFACE OF SAID SUBJECT TO FORM SAID STRATUM, PLACING A LIGHT-TRANSMITTING FILM IN CONTACT WITH SAID STRATUM-CONTAINING SURFACE, EXPOSING SAID FILM AND SURFACE TO INFRARED RADIATION FOR A TIME SUFFICIENT TO CAUSE SUBLIMATION OF QUANTITIES OF SAID SUBLIMEABLE MATERIAL FROM SAID IMAGE AREAS ONTO SAID FILM WITHOUT SUBSTANTIAL MELTING OF SAID MATERIAL, WHEREBY SAID SUBLIMED MATERIAL BECOMES AN INTEGRAL PART OF SAID FILM TO DUPLICATE SAID IMAGE AREAS THEREON, AND SEPARATING SAID FILM FROM SAID SUBJECT.