Abstract: In a color electrophotographic process wherein color toners are developed by toner flying under D.C. electric field, electrostatic capacitance of photoconductor (29, 30, 46, 65) is selected under 170 pF/cm.sup.2, so that undesirable discharging through the toner layer is prevented, and color contamination due to the discharging is prevented thereby providing clear color image printing.

Abstract: In an image forming method including the steps of electrostatically adhering light-transmissive particles onto the surface of a photoconductive substrate, exposing an image on the particles, and developing the image by separating the particles through which no light is transmitted from the particles through which light is transmitted in order to obtain a particle image consisting of one of the particle groups, the step of equalizing the potentials of the particles through which light is transmitted and those of the particles through which no light is transmitted is inserted between the exposure step and the development step. This additional step eliminates the defect in the conventional method in which degradation of color purity occurs at a thick color portion.

Abstract: The disclosure is directed to light-transmitting image forming particles each containing at least a colorless subliming dye which develops color through reaction with a color developing agent, and also a coloring agent, and moreover, having at least a pair of parallel faces. When applied to a particular image forming process as disclosed, the particles can provide color images with an expanded latitude and a superior color purity, while, by bevelling or planing-off the edges defining the parallel faces, exposure amount may be reduced as compared with particles without such bevelling.

Abstract: An image forming process comprising steps of arranging on a support member, in accordance with image signals, image forming particles containing dye former which develops its color in reaction with a color developing agent, heat-transferring the dye former from the particles to an image receiving substrate. After the heat-transfer step, the color developing agent is caused to adhere to the dye former heat-transferred on the image receiving substrate to provide colored images.Choice of the image receiving substrate and the color developing agent is expanded. Fogging is not caused, color purity is not lowered, and the other image receiving material is not polluted due to reevaporation of the dye former which is on the image receiving substrate and is not reacted with color developing agent.

Abstract: An image-receiving sheet for receiving a particle image electrostatically formed on a photoconductive surface and for fixing thereon a dye-image obtained by developing a sublimable dye former contained in the image particles. The sheet comprises a support member, color developing layer disposed on the support member and a dielectric layer disposed on the color developing layer. The color forming layer contains a developer material for developing the sublimable dye former. The dielectric layer exhibits in a low humidity range, a surface resistivity high enough to electrostatically retain the particle on the surface thereof and also exhibits adhesion high enough to adhesively retain the particles in high humidity range where the surface resistivity is below the required value for retaining the particles.

Abstract: The present invention is directed to a method and an apparatus for formation of images by particles on a photosensitive plate. Particles employed are translucent, whereby a charge holding the particles to the photosensitive plate may be efficiently removed from selected particles by image-wise light from an original document, etc., so ensuring production of well-defined images. For production of color images, there is employed a panchromatized plate and particles which are transparent to different types of light and have associated therewith dye material permitting production of clearly defined color images, it being made possible to obtain a color copy of an original document in a process requiring only one exposure stage and only one development stage.

Abstract: Disclosed is a light transmission particle containing a colorless sublimable dye, an acyl leucophenoxazine compound suitable for use in the formation of a color image. This particle can produce a clear color image having little fogging and having an excellent resolving power.

Abstract: Disclosed is a light transmitting particle containing a sublimable color-former that is a pyridine derivative suitable for use in the formation of a color image. This particle can produce a clear color image having little fogging and having an excellent resolving power.

Abstract: Disclosed is a light transmission particle containing a colorless sublimable dye that is a spirobenzopyrane indole compound suitable for use in the formation of a color image. This particle can produce a clear color image having little fogging and having an excellent resolving power.

Abstract: Image forming particles for use in electrostatic image formation, which particles have a light transmitting property, said particles comprising an electrically conductive material and subliming substance. The electrically conductive particles exhibit superior translucency which enables a charge preliminarily imparted to a photoconductive support member to be readily erased upon exposure to light image from an original, with consequent reduction of electrostatic attraction between the particles and the support member to minimum for presenting clear and definite images without fogging.

Abstract: The present invention relates to an electrophotographic color process comprising the steps of: (a) charging an electrophotographic light-sensitive material by corona discharge, said material having at least two kinds of color-producing photoconductive particles disposed at random on an electroconductive support, said color-producing photoconductive particles consisting essentially of a photoconductive particle, a sensitizer and a leuco dye, (b) exposing said charged material to light, (c) developing said material by toner containing acid substance, and producing color in the leuco dye by the interaction of the leuco dye with the acid substance, and forming a color image by carrying out once the procedure of charging, exposing and developing.