Photographic products and processes
US4886733A · kind A · utility
3Cited by
7References
23Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 3, 1988 |
| Grant date | Dec 12, 1989 |
| Priority date | — |
| Expiry date | Oct 3, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C8/36
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
This invention relates to diffusion transfer photographic processes adapted to be performed in the presence of ambient light and to diffusion transfer products useful in such processes wherein unexpectedly enhanced opacification in the red and near infrared region of the visible spectrum is achieved by employing phenanthrol/carboxynaphthol phthaleins as the light-absorbing, pH-sensitive optical filter agent for the longer wavelength region of the visible spectrum.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.