Philip a. Hunt Chemical Corporation

Robert P McElroy

Peter J Calabrese

Theron R Finch

Irving L Klavan

Arthur Greenberg

A method, apparatus and composition for developing an electric field image associated with the surface of an object by disposing said surface close to but out of contact with a surface of a liquid developer at a development zone. An electric field is in the configuration of an image. The magnitude of the electric field, and the distance between the surface of the object and the liquid surface at the development zone are such that at the development zone the electric field at or approaching the zone, with or without the assistance of an external electric field, segmentally raises closely spaced tiny amorphous (individually non-image-defining) pseudopods from the liquid developer surface toward the surface of the object. The pseudopods rise from the liquid surface under the influence of a segment of the electric field image and the tips of the pseudopods and/or droplets separated from these tips arrive at the surface of the object under the influence of the same field. The pseudopods and/or droplets reach the surface of the object in a conjoint configuration that creates a physical material image. At the background where no physical material image is to be formed on the object, the electric field is so weak that no developing liquid reaches the object whereby at these portions of the field the surface of the object is not touched by the tips of the pseudopods or by the droplets and, hence, remains dry and unaltered. In general, the background remains in its virgin state and provides an excellent contrast for the developed image.

Method, apparatus and compositions for liquid development of

An apparatus for developing a latent electrostatic image by passing the image close to but out of contact with a surface of a liquid developer at a development zone. The values of the magnitude of the charge of the image, the distance between the image segment and the liquid surface at the development zone, and the physical characteristics of the liquid are such that at the development zone the electrostatic field created by the segment of the image at the zone, with or without the assistance of an external electrostatic field impressed upon the development zone, raises pseudopods from the liquid developer surface which extend toward the carrier on which the electrostatic image is present. The pseudopods and/or droplets separated from the tip of the pseudopods surface under the influence of the electrostatic field created by the image segment, but are opposed by gravity. Where there is no latent image, the voltages, the gap and the physical characteristics of the developing liquid are such that no developing liquid reaches the carrier, so that these uncharged segments of the carrier are not touched by the tips of the spikes or the droplets, and hence, remain dry and not colored by the color of the liquid if the liquid is colored. These dry spots constitute the background against which the developed latent image is seen. Such background, due to the balancing of the factors mentioned, remains in its virgin state and provides an excellent contrast for the colored developed image.

Apparatus for liquid development of latent electrostatic images

A method for developing a latent electrostatic image by passing the image close to but out of contact with a surface of a liquid developer at a development zone. The values of the magnitude of the charge of the image, the distance between the image segment and the liquid surface at the development zone, and the physical characteristics of the liquid are such that at the development zone the electrostatic field created by the segment of the image at the zone, with or without the assistance of an external electrostatic field impressed upon the development zone, raises pseudopods from the liquid developer surface which extend toward the carrier on which the electrostatic image is present. The pseudopods and/or droplets separated from the tips of the pseudopods leave the liquid surface under the influence of the electrostatic field created by the image segment. Where there is no latent image, the voltage, the gap and the physical characteristics of the developing liquid are such that no developing liquid reaches the carrier, so that these uncharged segments of the carrier are not touched by the tips of the spikes or the droplets and, hence, remain dry and not colored by the color of the liquid if the liquid is colored. These dry spots constitute the background against which the developed latent image is seen. Such background, due to the balancing of the factors mentioned, remains in its virgin state and provides an excellent contrast for the colored developed image.

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Spring Valley, NY, United States of America

Robert P McElroy