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US 3,945,832 AGranted
Fogged, direct-positive silver halide emulsion containing desensitizers and a dimethine optical sensitizing dye
AssigneeFuji Photo Film Co., Ltd.
InventorsKeisuke Shiba, Masanao Hinata, Reiichi Ohi, Tadao Shishido
Life of this patent
Estimating the term…
Abstract
A direct positive silver halide photographic emulsion containing 1. at least one dimethine dye having the general formula (I): ##EQU1## 2. AT LEAST ONE COMPOUND HAVING THE GENERAL FORMULA (II): ##SPC1## 3. at least one compound having the general formula (III) ##EQU2## or the general formula (IV) ##SPC2## wherein Y, Y.sub.o, Z, L.sub.1, L.sub.2, R.sub.o, m, n, X, Z.sub.1, R.sub.1, X.sub.1, a, p, q, Y.sub.1, Y.sub.2, m.sub.1, R.sub.3, r, X.sub.2 and X.sub.3 are as hereinafter defined.
Claims14
A fogged direct positive silver halide photographic emulsion containing
- 1. at least one dimethine dye having the general formula (I):
- ##EQU5## wherein Y represents a non-metallic atom group necessary to complete a heterocyclic nucleus selected from the group consisting of a pyrole nucleus, an indole nucleus, a pyrazolo quinazolone nucleus, or a pyrazolo benzimidazole nucleus;
- Y.sub.o represents a hydrogen atom, an alkyl group, an aryl group, a carboxyl group, an alkoxy group, an alkoxycarbonyl group, a hydroxyl group, or halogen atom Z represents a nonmetallic atom group necessary to complete a 5- or 6-membered heterocyclic ring;
- L.sub.1 and L.sub.2 represents a methine group, and R.sub.o represents an alkyl group or an aryl group;
- m and n represents 1 to 2, and X represents an anion;
- 2.
3 more elements
Dependencies are inferred from the claim text.