Heretofore, a silver halide photographic light-sensitive material has been used extensively for a photoengraving process. This photoengraving process includes a step of converting an original having a continuous gradation into a halftone image, more specifically, a step of converting the various density levels of continuous gradation of the original into an accumulation of halftone dot patterns each having a dot area proportional to a specific density level on the original.
In this converting step, the original is photographed through a crossline screen or a contact screen with a silver halide photographic light-sensitive material having photographic properties of harder gradation, and the material is subjected to a developing process to form the halftone image.
To provide the photographic image with harder gradation, as disclosed in Japanese Patent Publication Open to Public Inspection No. 106244/1981 and U.S. Pat. No. 4,686,167, a compound such as hydrazine is incorporated as a so-called contrast improver into a silver halide photographic light-sensitive material. And, silver halide particles are used to effectively ensure the harder gradation capability of the above compound, and still other photographic additives are suitably combined to prepare a prescribed photographic light-sensitive material. The silver halide photographic light-sensitive material thus prepared is positively stable as a light-sensitive material and able to provide a high-contrast photographic image even when treated with a developer capable of rapid processing.
Such a silver halide photographic light-sensitive material, however, had a disadvantage that in converting an original having continuous gradation into a halftone image, pepper fogging or a so-called black pinpoint occurred to spoil the quality of the halftone image. To remedy such a disadvantage, various stabilizers or retarders having a hetero atom were used but not always effective.
USPTO Backgrounds
USPTO Backgrounds