Abstract: Disclosed is a process for forming an electrostatic latent image on a recording element having a dielectric layer superposed on a conductive electrode. In the first step of this process, the recording element and a xerographic sensitive element having a photoconductive layer also superposed on a conductive electrode are charged with the same polarity. In the second step, the photosensitive element is brought into virtual contact with the recording element so that the charged surface of the photoconductive layer in the photosensitive element is in face-to-face relationship with the charged surface of the dielectric layer in the recording element.

Abstract: Electrostatographic developer mixtures comprising finely-divided toner particles electrostatically clinging to the surface of carrier particles comprising a core having an outer coating thereon selected from terpolymers of vinyl chloride/vinyl acetate/vinyl alcohol and vinyl chloride/vinyl acetate/dibasic acid. The coated carrier particles have negative triboelectric charging properties and are particularly useful in reversal development systems. Imaging processes are also disclosed.

Abstract: An electrostatic copier has a rotatable copy drum and a developing unit which can be inserted and removed from the copier in toto. The developing unit is provided with bearing members which at least partly and loosely embrace the shaft of the copy drum.

Abstract: An electrophotographic photosensitive member having an insulating layer overlaid on the one side of an amorphous photoconductive layer is characterized in that said photosensitive member further comprises two layers: a charge injection layer and a subsidiary charge injection layer overlaid on the other side of the photoconductive layer with the subsidiary charge injection layer being interposed between the photoconductive layer and the charge injection layer, said subsidiary charge injection layer having a lower free charge density than that in the photoconductive layer and being able to make it easy to inject an amount of electric charge from the charge injection layer into the photoconductive layer whereas said charge injection layer has a higher free charge density than that in the photoconductive layer and serves as a main supply source of the electric charge to be injected into the photoconductive layer.

Abstract: Disclosed is a photoconductive recording element having a high photosensitivity over the entire band of visible rays which comprises an electroconductive substrate and a photoconductive layer formed on the substrate. The photoconductive layer comprises an acid dye and a basic dye both of which may be concurrently adsorbed on the outer surfaces of fine zinc oxide particles, or the acid dye of which is adsorbed on the outer surfaces of the zinc oxide particles and the basic dye of which is adsorbed on each layer of the acid dye.

Abstract: A toner head is disclosed for applying liquid toner to a moving record medium having a latent electrostatic image thereon, in which the contact surface of the head is curved in a cylindrical form to ensure proper engagement of the record medium during toning. Since the toner is circulated through the system by a vacuum pump arrangement, pressure relief means are provided to prevent an inward deflection of the record medium that could choke off toner flow during periods when the record medium is not moving over the toner head. In one embodiment, the toner head comprises a plurality of identical modules which are oriented alternately in opposite directions, so that some serve as toner inlet stations and some as exhaust stations. A toner clean-off head having a cylindrically curved contact surface is also disclosed.

Abstract: A transfer sheet on which toner images free of broadening of edge portions and having sharp contours can be transferred even in the electrophotography or electrostatic printing of the transfer type using conductive or semiconductive toners, i.e., magnetic toners, is disclosed. This transfer sheet is characterized in that a conductive or semiconductive toner-receiving face having a volume specific resistance of at least 3.times.10.sup.13 .OMEGA.-cm is formed on at least one surface of a substrate of the transfer sheet.

Abstract: A finely-divided toner composition comprising a thermoplastic vinyl resin and a surface active additive selected from the group consisting of fluorinated surfactants. The toner composition possesses controlled triboelectric charging properties while its other bulk properties remain unaffected. Developer compositions and electrostatographic imaging processes are also disclosed.

Abstract: The duration of use of spectrally sensitized pigment bonding agent layers which are to be used a number of times is substantially increased by performing floodlighting, after the development and/or transfer and prior to the recharging, with a light which is suitable per se for the image formation, but which is substantially not absorbed by the dye.

Abstract: An improved electrophoretic migration imaging process is disclosed wherein the improvement comprises the use of electrically photosensitive particles containing a colorant having an absorption maximum greater than about 410 nm. and having the formula: ##STR1## wherein n represents 0 or 1; m represents 1 or 2; Ar represents an aromatic group; Z represents the nonmetallic atoms to complete an aromatic group; and each of R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 represents hydrogen, nitro, cyano, halogen, or one of various specified organo groups.

Abstract: An improved electrographic recording apparatus and method. An electrographic recording medium has a charge retaining front surface on which charge is distributed in a pattern representing a desired image to be recorded, and a field permeable conductive layer. While charge is being deposited on the charge retaining surface of the electrographic medium, a field is established and maintained behind the rear surface of the medium, said field penetrating the conductive layer and having a field strength on the charged side of the medium that opposes a field that causes charge to be deposited on the charge retaining surface of the medium. In another aspect of this invention, the recording apparatus has a toner application station that is located apart from the charge depositing means, and a second field, having the same polarity as the first field, is established and maintained behind the rear surface of the electrographic medium at the toner station.

Abstract: 1,3,4-oxadiazole derivative expressed by the general formula ##STR1## wherein R represents alkyl having 1-4 carbon atoms, dialkylamino having 1-4 carbon atoms, diarylamino, phenyl, styryl, halogenophenyl, nitrophenyl, alkylphenyl having 1-4 carbon atoms, alkoxyphenyl having 1-4 carbon atoms, cyanophenyl, carboxylic ester substituted phenyl, dialkylaminophenyl having 1-4 carbon atoms, naphthyl, anthryl, or heterocyclic radical, is a photoconductive substance with high sensitivity and is a compound useful as a constituent of electrophotographic plate.

Abstract: A photosensitive material for use in electrophotography is disclosed which comprises a conductive support, a photoconductive layer superposed on said support and a protective layer superposed on said photoconductive layer, said surface protective layer containing an organic compound which has a structure according to the formula ##STR1## in a part of the molecule.

Abstract: A one-component magnetic developer powder for developing an electrostatic latent image formed according to an electrophotographic process comprising non-agglomerative essentially spherical members consisting essentially of plastics binder, magnetic particles and first electric conductive particles dispersed therein, and second electric conductive particles embedded on a spherical surface of the member, the resistivity of the surface layer of the powder being less than that of the inner portion.The developer powder according to the present invention has a good electrical uniformity and the flowability of the developer powder is very good. Productivity of the same is also very good.

Abstract: There is described an electrophotographic photoreceptor comprising a conductive metallic substrate, a composite interfacial structure made up of a layer comprising organic thermoplastic polymeric adhesive material and a thin layer of arsenic triselenide, and a photoconductive insulating layer comprising selenium or its alloys. The photoreceptor is formed by a method which includes depositing the arsenic triselenide layer while the substrate temperature is held at or above the softening point of the thermoplastic polymeric adhesive material but below the crystallization temperature of the arsenic triselenide and then depositing a layer of selenium or selenium alloy while the substrate temperature is held below the softening point of adhesive material and below the crystallization temperature of the selenium or selenium alloy.

Abstract: A novel toner system is provided employing a photodegradable toner. These toners are photodegradable during the fixing step in electrophotographic processes when they are exposed to light and then pressure or in the opposite sequences. This system provides excellent fixing of toner images at lower energy levels than is found in composition fixing systems.

Abstract: A composite particle comprising a conductive portion and an insulating portion. The insulating portion is integral and contiguous with the conductive portion.

Abstract: A method of obtaining a number of copies transferred from one electrostatic latent image produced on an electric charge carrying member coated on an electrically conductive transfer body is disclosed. The method comprises the successive steps of producing an electrostatic latent image charge on the transfer body, developing the electrostatic latent image charge into a toned picture image, applying a bias voltage between an electrically conductive screen arranged near a transfer receiving medium made in contact with the transfer body on the one hand and the transfer body on the other hand and at the same time charging the transfer receiving medium through the electrically conductive screen with a corona source of ions. The method can transfer the electrostatic latent image produced on the transfer body to the transfer receiving medium without damaging the electrostatic latent image at a high speed with a high efficiency.

Abstract: A photosensitive composition which comprises an electron donative organic photoconductive compound and a sensitizer having the formula ##STR1## wherein A represents an aromatic group or heterocyclic group which can be substituted by an inert group; R represents cyano, nitro, akoxycarbonyl, aryl or carbamoyl group; and n is 0 or 1.

Abstract: This invention is directed to photosensitive material for electrophotography and more particularly it is directed to the improvement of the properties with respect to humidity of photosensitive material by using photoconductive material in combination with ion exchange resin or by using photoconductive material which is previously washed in an aqueous solution in the presence of ion exchange resin.