| 摘要 |
The invention is the use of ultra-thin, tabular, light-sensitive grains in a Photographic emulsion for the purpose of increasing the sensitivity of films and plates. Silver halide is the preferred light-sensitive material. It is surprising that by using a fixed weight of light-sensitive material, tabular grains produce an emulsion that is more sensitive than when spherical grains are used, and the emulsion becomes more sensitive as the diameter-to-thickness ratio (aspect ratio) of the tabular grains increases. A consequence of using the ultra-thin, light-sensitive grains of the invention is increased covering power. This consequence has a profound economic advantage. An example is given where, by using the ultra-thin tabular grains of the invention, only one tenth as much silver is required. The teachings of the invention apply to emulsions on photographic films and plates both with and without a reflective backing. |
