Automatic replenisher system for a photographic processor
US4057818A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1975 |
| Grant date | Nov 8, 1977 |
| Priority date | — |
| Expiry date | Jun 25, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2509
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An automatic replenishing system for maintaining the chemical concentration of the liquid in a film processing tank, which automatically energizes a replenishing pump at regular timed intervals (e.g. every 30 seconds) regardless of whether or not the control circuitry indicates a need for replenishment, and which includes an element for sensing the density and velocity of the film and for producing a combined signal which controls the running time of the pump after each energization. The replenishing system also includes a second replenishing pump for maintaining the condition of the liquid in the processing tank, which second pump is energized automatically after a predetermined number of said regular timed intervals, or after a predetermined number of said regular timed intervals in which a zero film density or non-use condition has been detected for a preset running time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.