Tone control of photographic images
US5292627A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1992 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Jun 3, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/355
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Monocyclic and polycyclic azoles having the following formula modify the tone of a silver image formed from a fine grain radiation sensitive silver bromide or silver bromoiodide emulsion layer in which the silver bromide or silver bromoiodide grains have a mean equivalent circular diameter of less than 0.3 .mu.m. The azoles have the formula: ##STR1## wherein Z is --N.dbd. or --C(R.sup.5).dbd. where R.sup.5 is hydrogen, --NH.sub.2, aliphatic of 1 to 8 carbon atoms or aromatic of 1 to 8 carbon atoms; PA0 R.sup.4 is hydrogen, aliphatic of 1 to 8 carbon atoms or aromatic of 1 to 8 carbon atoms; PA0 R.sup.4 and R.sup.5 together complete a 5 or 6 membered heterocyclic nucleus containing 1 to 3 ring nitrogen atoms; PA0 L is a divalent aliphatic linking group containing 1 to 8 carbon atoms; PA0 T is an aliphatic terminal group containing 1 to 10 carbon atoms; PA0 m is 0 or 1; PA0 n is an integer of 1 to 4; and PA0 p is an integer of 2 to 4.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.