Agfa Gevaert Nv

Agfa-gevaert

Ludovicus P Joly

Serge M Tavernier

Guido Vital Desie

Jozef L Mampaey

Antonius A Rutges

Frank Ruttens

G&uuml;nther Dieltjens

Andr E Verhecken

A device for direct electrostatic printing (DEP) is provided comprising a device having an external surface carrying toner particles for generating a flow of toner particles to an image receiving member and a printhead structure, having two major faces, interposed in the flow of toner particles for image-wise modulating this flow, wherein the external surface moves in a direction A and the printhead structure is kept at a constant distance, D, from that external surface by spacing elements forming an angle between 45&deg; and 0&deg; with direction A and being located at a distance d from each other such that 1 cm&lE;d&lE;50 cm. In a preferred embodiment the spacing elements are located at a distance d such that 5 cm&lE;d&lE;35 cm and the constant distance D is kept between 25 and 500 &mgr;m.

DEP (direct electrostatic printing) device maintaining a constant distance between printhead structure and toner delivery means

Electrostatographic developer composition

A method is disclosed for preparing silver halide emulsions useful in photography. Said method comprises the step of precipitating silver halide grains in an aqueous solution of peptizer initially and finally under pAg values suitable for forming cubic silver halide crystals characterized in that at least once during the precipitation stage the pAg is increased for at least 10 percent by weight of the total amount of silver salt used during the precipitation by at least 1.5 units to such value whereby the formation of octahedral crystals would occur if that value were to persist over the entire precipitation stage. Preferably the increase of the pAg value is brought about after precipitation of between ten and twenty percent of the total amount of silver halide to be precipitated.

Process for the preparation of silver halide emulsions

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Hove, Belgium

Ludovicus P Joly