PURPOSE: To enable decrease in generation of a photographic fog owing to red safe light, increase in a terminal fog, etc. by maintaining the average content of silver iodide in particles in a specific range and providing the part where the silver iodide exists locally at a specific concn.
CONSTITUTION: If the average silver iodide content in silver halide particles is maintained at 0.5W10mol%, high sensitivity with a less photographic fog as well as good developing progressiveness and fixability are obtd. The part where high concn. silver iodide of at least ≥20mol% exists locally is provided in the silver halide particles. The outside of the part where the silver iodide exists locally is coated by silver halide contg. no silver iodide. If such a simple dispersion emulsion is used, a sensitization treatment such as chemical sensitization is thoroughly executed and extremely high sensitivity is obtd.; moreover, there is no tendency toward a softer gradation and high contrast is obtd. No red safe light fog is generated in this stage and thermal stability is extremely high.
UEDA KOUICHI
SUZUKI AKIO
