Patent · US Expired

Direct-positive photographic material

US4263396A · kind A · utility

4Cited by

6References

9Claims

0Family size

Assignee

Agfa-Gevaert NV · BE

Inventors

Sieghart Klotzer · Cologne, DE
Erik Moisar · Cologne, DE
Harald von Rintelen · Leverkusen, DE

Key dates

Filing date	Jan 10, 1980
Grant date	Apr 21, 1981
Priority date	—
Expiry date	Jan 10, 2000

Classification

Technology area (CPC G)Physics
CPC primaryG03C1/48538
WIPO fieldOptics
WIPO sectorInstruments

Abstract

An improvement in the stability of a direct positive emulsion layer in photographic material is obtained by the inclusion of a compound which provides in the image-wise exposed and developed direct positive emulsion layer a greater difference between the density of the image in the unexposed parts of the layer and the density in the exposed parts. The compound provides in the emulsion a characteristic curve related to a density value at maximum density which is at least twice the analogous density value at minimum density.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.