| 摘要 |
PURPOSE:To obtain a direct positive photographic sensitive material good in storage stability and wide in exposure latitude by forming a core/shell type silver halide emulsion composed substantially of cubic grains or tetradecahedral grains consisting mainly of (100) planes contained in the silver halide emulsion layer nearest to a support. CONSTITUTION:Each of core/shell type silver halide grains to be used are, preferably, in a monodispersed state and a preferable average grain diameter of 0.1-4mum, and the expression that the emulsion is composed substantially of cubic grains or tetradecahedral grains consisting mainly of the (100) planes means that, especially preferably, the grains amounting to >=95% of the core/ shell type silver halide grains are the cubic grains or tetradecahedral grains consisting mainly of the (100) planes. Each of said core/shell type silver halide grains constituting the silver halide emulsion layer is obtained by preparing the inner core of the silver halide grain chemically sensitized or doped with metal ions or subjected to both treatments, coating its surface with the outer shell of the silver halide grain, and further, chemically sensitizing the outer shell. |
