Agfa Gevaert Nv

Afga-gevaert Nv

Willy Joseph Vanassche

Herman Alberik Pattyn

Sieghart Klotzer

Erik Moisar

Herman Adelbert Philippaerts

Hendrik Alfons Borginon

Francois Leon Schelfaut

Rene Omer Duville

Robert J Pollet

Jozef Frans Willems

Otto Lapp

Antoon Leon Vandenberghe

Raymond Gerard Lemahieu

Luc A De Brabandere

Henri Depoorter

Theofiel H Ghys

Jules Robert Berendsen

Yvon Louis Renotte

Direct positive silver halide emulsions are provided which contain fogged silver halide grains the said grains being heterodisperse and containing silver iodide in an amount of more than 10 mole % and at most 20 mole % relative to the total amount of silver halide. The emulsions have increased sensitivity and reduced gradation which is suitable for continuous tone reproduction.

Direct-positive emulsion containing fogged, silver halide grains of

A method is described of making reversal images in Lippmann-emulsions wherein the emulsion is image-wise exposed and subjected to a first stage development so that a negative silver image of the original is formed but some silver halide is left in the exposed areas, and then to a second stage development under fogging conditions to develop said residual silver halide in the exposed areas, whereafter the silver developed in said first and second development stages is bleached and the active silver halide then still remaining in the emulsion is converted to form a positive image.

Reversal processing of exposed Lippman-emulsions

A photographic material is described for making positive images by reversal processing, the material comprising a support and a silver halide Lippmann-emulsion layer the average silver halide grain-size of which is less than 100 nm wherein the grains have been chemically sensitized to fog so that a test portion of the emulsion when coated on a support at a coverage of silver halide corresponding to from about 3 g to about 7 g of silver nitrate per sq.m. gives a density between about 0.20 and about 0.70 upon development without exposure for 6 min at 20.degree. C in a developer of the composition:

Lippmann-emulsions and reversal processing thereof

Novel antihalation layer(s) for use in a light-sensitive silver halide element and comprising a 5-pyrazolone-monomethine oxonol of formula I and a 5-pyrazolone-pentamethine oxonol of formula II : ##STR1## wherein: EACH OF R.sup.1 and R.sup.3 represents an alkyl group or an aryl group,

Light-absorbing dyes for silver halide material

Reduction and gold fogged Lippmann emulsions are described wherein the emulsion is fogged with from 0.07 to 0.5 milliequivalents of reduction fogging agent and from 0.01 to 0.1 millimole of gold fogging agent per mole of silver halide and the emulsion comprises more than 2 g and at most 10 g of electron acceptor(s) per mole of silver halide.

Direct-positive silver halide emulsions

A method of producing direct-positive images is provided which comprises developing an exposed direct-positive silver halide emulsion comprising electron-traps and fogged silver halide grains in the absence of halide ions so as to obtain higher maximum density. It is possible to decrease the degree of fogging so as to obtain direct-positive emulsions of high-sensitivity which, when developed in the absence of halide ions, still provide favorable maximum density values.

Developing low fogged, direct-positive silver halide emulsion with an

Direct positive silver halide emulsions are provided which contain fogged silver halide grains with a layered grain structure wherein the external shell of the silver halide grains comprise up to 20 mole % of silver iodide based on the silver halide of the shell. The emulsions show improved sensitivity and produce images of improved maximum density.

Direct positive silver halide elements

Direct-print images of improved stability against prolonged light-exposure are obtained in a photodevelopable element by spectrally sensitizing the photodevelopable emulsion, providing in the emulsion layer or a superposed layer a compound absorbing radiation in the inherent sensitivity range of the silver halide, and effecting image-wise exposure with radiation comprising light of the spectral range for which the silver halide has been spectrally sensitized.

Photodevelopable silver halide material

Direct positive silver halide emulsions are provided which contain fogged homodisperse silver halide grains having a silver iodide content of more than 10 mole % and at most 20 mole % relative to the total amount of silver halide. These emulsions have higher sensitivity than corresponding fogged emulsions with less silver iodide content.

Direct positive emulsions containing fogged, monodispersed silver halide

Direct-positive emulsions are described comprising incorporated developing agents wherein the developing agents are 1,4-dihydroxybenzene compounds of which at least one of the hydroxyl groups has been esterified to form a hydrolyzable aliphatic acyloxy group comprising a quaternary ammonium group.

Direct-positive silver halide emulsions having incorporated developers

A method is described of preparing a blend of direct-positive silver halide emulsions that has a pAg value of at least 8.35 from two or more direct-positive silver halide emulsions of different average grain-sizes comprising fogged silver halide grains and having pAg values below 8.35, without inducing physical ripening, by raising the pAg to the value of at least 8.35 before or after blending the emulsions, and providing at least one electron-accepting or halogen-conducting compound, at the surface of the fogged silver halide grains prior to raising the pAg to the value of at least 8.35.

Method of preparing a blend of fogged, direct-positive silver halide

Reduction and gold fogged direct-positive Lippmann-emulsions have improved gradation and higher maximum density when fogging occurs in the presence of a palladium compound.

Direct-positive silver halide emulsion reduction and gold fogged in

Direct-positive silver halide emulsions comprising fogged silver halide grains and an electron acceptor are described wherein the emulsion is spectrally sensitized by means of 2-aryl-indolocarbocyanines. The combination of electron acceptors and these spectral sensitizers provides super-sensitizing effects that are not impaired by the presence of color couplers.

Direct-positive super-sensitized silver halide emulsions

Direct-positive silver halide emulsions are described which have been fogged so that a test portion thereof when coated at a coverage of 0.50 to 5.50 g of silver per sq.m. gives a density below 0.50 upon processing without exposure for 6 min. at 20.degree.C in a developer I and an identical coated test portion gives a density that is at least twice that of the first test portion with a minimum of 0.50 upon processing without exposure for 3 min. at 20.degree.C in a developer II. The emulsions have high photographic speed and though fogged to a very low degree can yield direct-positive images of satisfactory density.

Direct-positive silver halide emulsion fogged to low level and the use

Direct-positive silver halide emulsions comprising fogged silver halide grains and having adsorbed to the surface of said grains an electron-acceptor have improved stability and speed when subsequent to fogging of said grains and addition of the said electron-acceptor the pH of the emulsion is lowered, preferably below pH 6.

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Kontich, Belgium

Willy Joseph Vanassche