Photographic film unit

Claim 1

A PHOTOGRAPHIC FILM UNIT ADAPTED TO PROVIDE WITHIN ELEMENTS OF SAID FILM UNIT BOTH A LATENT NEGATIVE IMAGE AND A VISIBLE POSITIVE IMAGE OF SUBJECT MATERIAL OF A PHOTOGRAPHIC EXPOSURE, SAID PHOTOGRAPHIC FILM UNIT COMPRISING AN ENVELOPE FORMED OF A MATERIAL SUBSTANTIALLY OPAQUE TO ACTINIC RADIATION, SAID ENVELOPE HAVING A FRONT AND A REAR SURFACE, BEING SEALED ALONG THREE EDGES AND HAVING AN UNSEALED FOURTH EDGE, MEANS COMPRISING AT LEAST ONE STRIP ATTACHED TO ONE OF AID ENVELOPED SURFACES ADJACENT SAID UNSEALDED EDGE FORMING LIMIT STOP MEANS FOR CONTROLLING THE WITHDRAWAL OF SIAD ENVELOPE FROM ITS COVERING POSITION WITH RESPECT TO A CONTAINED SHEET MATERIAL, A FIRST SHEET-LIKE ELEMENT HAVING A SURFACE FOR FORMING SAID POSITIVE IMAGE RELEASABLY ATTACHED TO AN INNER SURFACE OF SAID ENVELOPE, A SECOND SHEET-LIKE ELEMENT SLIDABLY CONTAINED IN SAID ENVELOPE HAVING A PHOTOSENSITIVE SURFACE FACING SAID POSITIVE IMAGE-FORMING SURFACE FOR FORMING SAID LATENT NEGATIVE IMAGE, A SPRING CLIP ATTACHED TO THE EDGE OF SAID LAST-NAMED SHEET-LIKE ELEMENT WHICH IS POSITIONED ADJACENT SAID UNSEALED FOURTH EDGE OF THE ENVELOPE, SAID CLIP SERVING TO ENCLOSE SAID UNSEALED FOURTH EDGE OF THE ENVELOPE AND TO COMPRESS AND RELEASABLY HOLD AT LEAST THE EXTREMITIES THEREOF TIGHTLY TOGETHER TO PREVENT ADMITTANCE OF SAID ACTINIC RADIATION, SAID CLIP ALSO SERVING TO HOLD SAID ATTACHED SHEET-LIKE ELEMENT HAVING SAID PHOTOSENSITIVE SURFACE STATIONARY WHEN SAID ENVELOPE IS WITHDRAWN THEREFROM TO PHOTOGRAPHICALLY EXPOSE SAID SURFACE, AND A COMPRESSIBLE FLUID CONTAINER FIXEDLY HELD AT A GIVEN LOCATION WITHIN THE ENVELOPE BETWEEN SAID IMAGE-FORMING SURFACES, SAID CONTAINER EXTENDING TRANSVERSELY OF SAID SURFACES AND RELEASABLY CONTAINING A GIVEN QUANTITY OF A PROCESSING FLUID ADAPTED TO BE RELEASED FROM SAID CONTAINER BETWEEN SEPARABLE EDGES THEREOF AND SPREAD BETWEEN SAID IMAGEFORMING SURFACES WHEN MECHANICAL STRESS IS PROGRESSIVELY APPLIED TO THE EXTERNAL SURFACES OF SAID ENVELOPE.