The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 18, 1977
Filed:
Aug. 02, 1974
Peter O Kliem, Weston, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
The present invention relates to photography and, more particularly, to diffusion transfer process photographic film units which comprise a photosensitive element adapted to provide, by diffusion transfer photographic processing, selective dye image recordation of incident actinic radiation as a function of the point-to-point degree of photosensitive element exposure, which film unit includes a plurality of photosensitive units each exhibiting a predetermined gamma of substantially the same value and within a range of 1.1 to 1.7 and at least one of the units includes, in contiguous relationship, a first silver halide photosensitive layer comprising a particulate dispersion of photosensitive silver halide crystals, preferably silver iodobromide, iodochloride and/or iodochlorobromide crystals, possessing a first gamma and a second silver halide photosensitive layer possessing a second gamma having disposed therein dye developer which is diffusible during processing as a function of the point-to-point degree of silver halide layer exposure to incident actinic radiation. The value of the first said gamma differs from that of said second gamma by at least about 0.25, said gammas, taken together, are within the range of about 1.7 to 3.0 and each is greater than the predetermined gamma, said first silver halide layer exhibits sensitivity to incident radiation actinic to the layer in excess of the sensitivity exhibited to said radiation by said second silver halide layer; and the photographic speed differential between said first and said second layer is within the range of about 1 to 7 stops, and a layer adapted to receive dye diffusing thereto; and to specified diffusion transfer processes employing such film units.