Direct positive photographic materials.

摘要

A direct positive photosensitive material composed of a support having thereon at least one silver halide light-sensitive emulsion layer containing the combination of (a) non-prefogged internal latent image silver halide grains; (b) a binder; (c) at least one compound represented by formulae (I), (II) or (III); and at least one compound represented by formula (IV): R-SO2S-M (I) R-SO2S-R<1> (II) R-SO2S-Lm-S.O2S-R<2> (III) wherein R, R<1> and R<2> each represents a substituted or unsubstituted aliphatic group, a substituted or unsubstituted aromatic group or a substituted or unsubstituted heterocyclic group; M represents a cation; L represents a divalent linking group; and m is 0 or 1; and R<3>-SO2-M<1> (IV) wherein R<3> represents an aliphatic group, an aromatic group or a heterocyclic group; and M<1> represents a cation. The material provides a direct positive image with high Dmax, low Dmin and high contrast.