Method of using a test film to measure developer activity
US4004923A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 14, 1975 |
| Grant date | Jan 25, 1977 |
| Priority date | — |
| Expiry date | Jan 14, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C5/31
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method of controlling developer activity in the processing of photosensitized printing plates; comprising, exposing a photographic test film, comprising, a film adapted to pass substantial amounts of light through some portions thereof and substantially lesser amounts of light through other portions thereof, preferably transparent portions and opaque portions, and having a background area and a plurality of insets separated from one another and surrounded by and separated by the background area, the background area having a plurality of regularly spaced dots, having a relatively small total dot perimeter per unit area and a constant dot size and adapted to pass substantial amounts of light through said dots, separated by lines adapted to transmit substantially lesser amounts of light through said lines, each of the insets having a plurality of regularly spaced dots, having a larger total dot perimeter than the small dot perimeter and constant dot size and adapted to pass small amounts of light through said dots, separated by lines adapted to pass substantially larger amounts of light through said lines, and the dot sizes from one inset to another differ progressively in said plur…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.