Elevated iodide surface laminae tabular grain emulsions
US5576172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1995 |
| Grant date | Nov 19, 1996 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/09
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A tabular grain emulsion is disclosed that combines increased speed, reduced low intensity reciprocity failure, and low levels of pressure sensitivity. The tabular grains containing greater than 70 mole percent bromide and laminae located adjacent the {111} major faces each having a thickness of less than 35 nanometers and containing at least 1 mole percent higher iodide than a host portion of the tabular grains on which they are deposited. The tabular grains contain an iridium dopant capable of reducing low intensity failure in one interior grain portion and a Group 8 speed enhancing dopant present in a concentration of from 20 to 300 molar parts per million in another interior grain portion separated from the iridium containing grain portion by at least 10 percent of the silver forming the grain structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.