Apparatus for use in optimizing photographic film developer apparatus
US5664252A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Jun 7, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03D13/007
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
To provide a standard for determining an objective level of performance of photographic film developer processes, a production sensitometer, of the type commonly used in the field, is correlated with a high precision, master sensitometer, defined as a standard. Relative exposure values are computed for each step of a step wedge exposed by a production sensitometer with reference to a corresponding step of a step wedge exposed in the master sensitometer. The relative exposure values are recorded and stored in a read-only memory in the production sensitometer. In the field, the steps of a step wedge on a test film strip exposed by the production sensitometer and developed by the developer processor to be tested, are read by a densitometer which uses the stored relative exposure values to compute density values for the test strip correlated to the master sensitometer. The developer processor may then be adjusted such that the developed film will match quality control parameters, e.g. speed index, contrast index, etc., supplied by the film supplier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.