Method for making negative lith images direct positive images

Abstract

A photographic light-sensitive silver halide material is provided for making negative lithographic images or direct-positive images, said material comprising a support, at least one internal latent image-type silver halide emulsion layer (in the case of direct-positive materials) or surface latent image-type silver halide emulsion layer (in the case of lithographic materials) and development-nucleating amounts of a compound or a precursor thereof, said compound having at least one quaternary heterocyclic ring system comprising at least three rings including a tetrahydropyridinium ring wherein carbon-nitrogen and carbon-carbon double bonds are also part of an aromatic ring being one of said three rings and wherein said double bonds and nitrogen atom in said tetrahydropyridinium ring are incorporated into annelated conjugated ring systems. Developing said photographic material after exposure in an alkaline surface developer rapidly converts said precursor into a ring system as defined hereinbefore.

Dependencies are inferred from the claim text.