Japanese Patent JPS5347003

B1

1,269,260. Direct-positive silver halide emulsion compositions. EASTMAN KODAK CO. Aug.28, 1969 [Sept. 9, 1968], No.42919/69. Heading G2C. A direct-positive photographic silver halide emulsion composition comprises a mixture of at least two portions of silver halide grains which have been fogged to different fog levels. The mixture preferably comprises two to four portions of silver halide grains which have been chemically fogged to different fog levels whereby the characteristic curve of the emulsion composition has discrete steps. When a plurality of portions of silver halide grains is used the characteristic curve may be a smooth continuous curve. The emulsion compositions are preferably bluesensitive (i.e. they will form direct-positive images on exposure to light in the 350-500 nm region of the spectrum followed by processing), but the sensitivity may be extended into the green and red regions by using sensitizing dyes. All the silver halide grains preferably have substantially the same diameter and preferably have an average diameter of less than 2 microns. These emulsions have extended exposure latitude.

JP7063369A

December 18, 1978

September 08, 1969

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G03C1/485; (IPC1-7): C03C1/02

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