Abstract: An electrostatic copying apparatus has a housing having at its top surface a transparent plate on which to place an original to be copied, a rotary drum disposed within the housing and having a photosensitive member on its surface, a charging, a developing, a transferring and a cleaning mechanism which are successively arranged around the rotary drum in the moving direction of its surface, an optical system for projecting the image of the original onto the surface of the rotary drum between the charging means and the developing means, and a receptor sheet conveying system for transferring a receptor sheet through a transfer station defined between the surface of the rotary drum and the transferring mechanism.

Abstract: A copying system and apparatus wherein a first electrostatic image of an original is formed and developed on a first photoconductive surface, and second electrostatic images of the developed image are repeatedly formed on a second photoconductive surface by illumination of the first surface. The second images, which can be formed at high speed, are developed and transferred to copy material.

Abstract: In an electrically activatable recording element improvements are provided by an electrically conductive interlayer (ECI layer) separating (a) an electrically activatable recording layer from (b) a photoconductive layer or electrical activating means. The ECI layer comprises electrically conductive particles uniformly dispersed in an electrically insulating binder. The interlayer enables imaging with a minimized air gap between (a) and (b). The recording element is room light handleable. The element provides an image by dry development processing or by means of processing solutions.

Abstract: The present invention is a reproduction machine having a scanning device for projecting images of documents onto a moving photosensitive surface wherein the control of the reproduction machine is a function of the size of the copy sheets. The copy sheets are fed from a copy sheet supply into communication with a registration switch to determine the length of the copy sheet. A counter responsive to the switch converts the length of the copy sheet into a scan drive signal. The scan drive signal is used to terminate the scan drive in accordance with the length of the copy sheet.

Abstract: An image-forming method suitable particularly for copying using image exposure wavelengths of 700 to 850 nm such as are experienced with semiconductor laser beam printers. Useful photosensitive members include photoconductive layer prepared from a dispersion of a photoconductive material including at least cadmium sulfide in a resin binder. The photosensitive member is sequentially subjected to a plurality of prehysteresis operations, each comprising electrostatically charging the member and uniformly exposing the same to light until the photosensitivity of the photosensitive member has been substantially stabilized.

Abstract: A method and an apparatus for charging a dielectric layer electrostatically to a predetermined potential. An AC electrode is arranged at a distance from the dielectric layer and connected to one output of an AC voltage generator. The AC voltage generator has the other output connected to an output of a DC voltage generator. Between the AC electrode and the dielectric layer there is a DC electrode which is connected to the other output of the AC voltage generator. The dielectric layer rests on a counter-electrode which is connected to the other output of the DC voltage generator and is at ground potential. Each of the electrodes can comprise one or a plurality of mutually insulated single electrodes.

Abstract: Either a single copy or a plurality of copies of an original document may be made. Making a single copy or the last copy of a plurality of copies comprises, during a first revolution of a photoconductive drum, electrostatically charging the drum, radiating a light image of the document onto the drum to form an electrostatic image, developing the electrostatic image using a magnetic brush to form a toner image, transferring the toner image to a copy sheet, electrostatically discharging the drum and uniformly radiating the drum with light to further discharge the same. During a second revolution of the drum the drum is cleaned with the same magnetic brush to remove residual toner, and again electrostatically discharged and uniformly radiated. During a third revolution of the drum the magnetic brush is again used for cleaning.

Abstract: An electrophotographic photosensitive member comprises isolated conductive members forming picture elements, a photoconductive layer, transparent electrodes and color filter electrodes.

Abstract: An electrophotographic method for color image formation, wherein use is made of an electrophotographic photosensitive member having a multitude of isolated electrically conductive members for forming image elements, a photoconductive layer, and a multitude of sets of electrodes for determining an electric potential of the isolated electrically conductive members in correspondence to a color image original, each set of electrodes comprising a non-transparent electrode, a transparent electrode, and color filter electrodes, and wherein a voltage is applied across the electrodes followed by development.

Abstract: A glass pane on which an original is placed and a focusing lens are stationary in the space of a copying machine. An original to be copied is placed on the glass pane in planar form. A pair of reflecting mirrors disposed on the image side of the focusing lens successively reflect exposing light flux from the focusing lens to pass it onto an exposure station on the photosensitive member. The surface of the photosensitive member moves in a given direction at a uniform rate while the pair of reflecting mirrors move in independent directions to achieve a slitwise exposure of the photosensitive member at a given location.

Abstract: A photoconductive material (11) coated on a drum, belt or sheet (22) is formed with a first photoconductive layer (11b) which is insensitive to red light, a second photoconductive layer (11d) which is sensitive to red light and a transparent insulating layer (11c) formed either between the photoconductive layers (11b), (11d) or on top thereof. The outer surface of the material (11) is radiated with white light while applying a first electrostatic charge thereto rendering both photoconductive layers (11b), (11d) photoconductive. Then, the material (11) is radiated with red light rendering only the second photoconductive layer (11d) photoconductive while applying an electrostatic charge of opposite polarity. Then, a third electrostatic charge of the same polarity as the first electrostatic charge is applied in the dark. The result is that electrostatic charges of opposite polarities are formed at the outer surfaces of the first and second photoconductive layers (11b), (11d).

Abstract: A printing plate making attachment for a graphic art camera taking the place of the ordinary silver halide film cartridge back. The attachment includes an endless belt of flexible electrophotograhic film that is charged by a source of corona, exposed and then rotated to a location where an ink-receptive toner in liquid form is applied to the resulting latent image under bias conditions. A supply of plate material such as paper, aluminum, plastic or other flexible substrate material is included and a single sheet of the plate material is fed into the nip of a pressure roller engaging against the endless belt, causing the toned image to be transferred from the belt to the plate material. The plate material containing the toned image is then fed past a fixing station and thereafter dispensed as a completed plate. The plate is suitable for us in an offset printing press.

Abstract: This invention is directed generally to a layered inorganic photoresponsive device, this device being comprised of a substrate, or supporting base, containing on its surface a layer of hole injecting material comprised of gold, a hole transport layer in operative contact with the hole injecting layer, the transport layer being comprised of a halogen doped selenium arsenic alloy, wherein the percentage of selenium present is from about 99.5 percent to about 99.9 percent, the percentage of arsenic present is from about 0.5 percent to 0.1 percent, the percentage of halogen present ranges from about 10 parts per million to 200 parts per million, followed by a charge generating material overcoated on the transport layer, this material being comprised of inorganic photoconductive substances, and as an optional layer a layer of insulating organic resin overlaying the charge generating layer. The transport and generating layers can also be comprised of one composite layer.

Abstract: This invention is generally directed to inorganic overcoated photo-responsive devices comprised of a substrate, a layer of hole injecting material capable of injecting holes into a layer on its surface, this layer being comprised of trigonal selenium, a hole transport layer in operative contact with the hole injecting layer, this layer being comprised of a halogen doped selenium arsenic alloy, wherein the percentage by weight of selenium present is from about 99.5 percent to about 99.9 percent, the percentage by weight of arsenic present is from about 0.1 percent to about 0.5 percent, and the halogen is present in an amount of from about 10 parts per million, to about 200 parts per million; a charge generating layer overcoated on the hole transport layer, comprised of an inorganic photoconductive material; a hole trapping layer overcoated on the generator layer, the trapping layer being comprised of a halogen doped selenium arsenic alloy, containing from about 95 percent selenium, to 99.

Abstract: A method of producing printed circuit boards according to this invention consists of the steps of coating an electrophotographic photosensitive film on both sides of a substrate which consists of a synthetic resin plate with a conductive metal layer on each side; forming a wiring pattern of an acid-resistant toner on the photosensitive film by means of the electrophotography; and etching the substrate to remove unnecessary parts of the conductive metal layers that are not covered with the protective toner and the photosensitive film. With this method, copper-walled holes can be formed easily and accurately.

Abstract: A thin film of material such as metal is deposited on the surface of a substrate by placing a substrate (22) into a chamber (10) containing holder (12) cooled by heat exchanger 18. A beam (56) of U.V. light from the illumination source (42) is projected through monochromator (43), mask (46) and lens (16) onto a selected area (58) of the substrate at an energy level exceeding the photoemission threshold of the surface. A slow electron (60) is ejected from the surface into the capture zone (62). A compound AB such as iron pentacarbonyl from supply (30) is leaked into the chamber (10), enters the capture zone (60) to form a highly reactive deposition fragment A.sup.- which attaches to the surface and a dissociation fragment which is evacuated through outlet (14). The deposited fragment may further dissociate to form metal deposit.

Abstract: In a process for the formation of an electrostatic image on a photoconductive element comprising a photoconductive zinc oxide-binder layer and an insulating top layer, the top layer is first positively charged and then is negatively charged until the element is saturated with negative charge, after which the top layer is imagewise exposed to light.

Abstract: A multiple function image processing system having both light-lens and flying spot beam for producing latent electrostatic images of originals on a photoconductive surface. The images are developed and transferred to a copy substrate material. A flying spot image reading beam enables the developed images to be read. Where multiple copies are desired, the light/lens provides the first image with later copies provided by the flying spot beams which scan each developed image and, using image signals produced by said scanning, write the next successive image until the desired number of copies are produced. Where a relatively large number of copies are desired, the image signals produced by scanning the developed image are stored in memory, which is thereafter used as the source of image signals for subsequent copies.

Abstract: This invention is generally directed to inorganic overcoated photoresponsive devices comprised of a substrate, a layer of hole injecting material capable of injecting holes into a layer on its surface, this layer being comprised of trigonal selenium, a hole transport layer in operative contact with the hole injecting layer, this layer being comprised of a halogen doped selenium arsenic alloy, wherein the percentage by weight of selenium present is from about 99.5 percent to about 99.9 percent, the percentage by weight of arsenic present is from about 0.1 percent to about 0.5 percent, and the halogen is present in an amount of from about 10 parts per million, to about 200 parts per million; a charge generating layer overcoated on the hole transport layer, comprised of an inorganic photoconductive material; and a layer of insulating organic resin overlaying the charge generating layer.

Abstract: An electrostatic latent image residing on an electrically insulating surface used to induce a similar image on a sectionally conductive member by bringing one surface of the sectionally conductive member into proximity with the latent image while the opposite surface of the sectionally conductive member is brought to ground potential. The sectionally conductive member is then removed from proximity with the latent image. To prevent electrical breakdown during removal, a grounded electrode is placed adjacent the surface of the sectionally conductive member opposite the latent image but separated from the sectionally conductive member by a thin electrically insulating layer. A latent image is thus formed on the sectionally conductive member which can be developed by conventional means such as with electroscopic materials well known in the xerographic art.

Abstract: A reflex exposure imaging member including a transparent conductive support member and a photoconductive layer disposed on said support member and an optical screen disposed between the photoconductive layer and the support member wherein the photoconductive layer includes an N,N'-diphenyl, N,N'-substituted diphenylbenzidine compound and a pyrylium, thiapyrylium or selenapyrylium salt in an insulating binder, the photoconductive layer having a thickness of about 5 to about 20 microns and an optical density of from about 0.1 to about 0.8.

Abstract: A motion picture film having a plurality of digitally coded soundtracks which are colorless and transparent to visible light and which fluoresce when exposed to ultraviolet light, unexposed film for providing the product, and the method for producing the product and methods for producing the exposed and unexposed films. The soundtrack images which overlie at least a portion of the visible image area of the film are digitally coded on the film using an electrostatic imaging system to imprint a fluorescent toner. The toner may comprise a fluorescent polymer having covalently bonded 3-phenyl-7-(amido or imido)-coumarin or certain substituted stilbenes or N-alkyl-4-aminonaphalimides.

Abstract: A planar array of microcells is formed in a support. An electrostatic charge pattern is established on the support differentiating first and second interlaid sets of microcells. An electrographic imaging composition is introduced into the first set of microcells, and a second, differing imaging composition is introduced into the second set of microcells. Multicolor photographic elements, particularly dye image transfer photographic elements, can be prepared.

Abstract: A process for improving the photoelectric properties of a laminated charge image carrier. In the process, an insulating layer, which can be doped before or after application, is applied between the substrate and the photoconductive layer. The insulating layer can also be applied in layers, one of which can be doped. Suitable dopants are acid, alkaline and halogen vapors, sensitizers and pigments.

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.

Abstract: An electrophoretic display including a cell having two plates spaced apart and provided at least regionally with electrodes, where at least one plate and an associated electrode facing the observer are transparent. The cell contains a suspension consisting of an inert dielectric liquid phase and a dispersed solid phase which at least in part are optically discriminable electrophoretic particles. The individual electrophoretic particles each are of practically the same density as the liquid phase, and at least part of the electrophoretic particles are pigment particles provided with a coating of organic material which is solid at the cell operating temperature but which melts at higher temperatures. The coating material contains at least one charge control agent. The charge control agent, preferably a salt of a divalent metal or metal of higher valency and of an organic acid, imparts a well-defined, uniform surface charge and a well defined, uniform surface potential to the particles.

Abstract: A process and apparatus for forming an electrostatic image on a photosensitive plate having a conductive base, a photoconductive layer overlying the base and exhibiting p-type or n-type semiconductivity, and an insulative layer overlying the photoconductive layer. The photosensitive plate is characterized in having carrier charge of a polarity corresponding to the conductivity type of the photoconductive layer injectable from the conductive base into the photoconductive layer and bound in the region of the interface between the insulative and photoconductive layers. The conductive base is transparent to activating light and the insulative layer is opaque to the activating light. A first charge of a polarity opposite to the conductivity type of the photoconductive layer is applied onto the insulative layer to inject and bind carrier charge in the region of the interface between the insulative and photoconductive layers.

Abstract: A triple function image processing system incorporating, for operation in a first COPY mode, a light/lens imaging system for imaging originals at a viewing station or platen to produce latent electrostatic images thereof on a photoconductive surface. The electrostatic images are developed and transferred to a copy substrate material as in conventional xerographic systems. A flying spot light beam is provided in a second WRITE mode, the flying spot beam writing images on the photoconductive surface in response to image signals input thereto. In this mode of operation, the beam impinges on the photoconductive surface at a location upstream of the developing device. And, in a third READ mode, the beam is impinged on the photoconductive surface downstream of the developing device to scan images developed on the photoconductive surface. The scattered light is collected and converted to image signals representative of the image scanned.

Abstract: A photoconductive material (11) is provided which has first and second photoconductive layers (13), (14) of different spectral sensitivities. The material (11) is charged at least twice to form a stratified charge pattern of opposite polarities. A color light image of an original document (24) is radiated onto the material (11) to form an electrostatic surface potential pattern having high and low potential areas of one polarity and another area of the opposite polarity corresponding to three respective colors. The areas are developed separately using toners of the three respective colors to form a three color toner image which is transferred to a copy sheet (36). One of the colors may be black.

Abstract: The method of forming a charge-image on a charge-retaining object by applying an electrical image-activating energy and a mechanical image-activating energy in a manner to result in the functional dependence of the charge density of the consequent charge-image to the magnitudes of the image-activating energies and to the length of the activating time period, enabling the charge-image or the subsequent visible image to have a uniform desired level of desired density, controlled multiple levels of density, controlled continuously varying density, or a combination thereof. It also enables the trading off of charge density for a lower image-activating voltage and the trading off of charge-imaging speed for higher charge density. The resulting image is of high fidelity to the original.

Abstract: Disclosed is an adhesive generating layer for use in an overcoated photoreceptor system, this layer containing a generating pigment dispersed in a copolymer of a siloxane and a dihydroxy compound of the formula: ##STR1## wherein R and R' are independently selected from the group consisting of alkyl, substituted alkyl, alkenes, substituted alkenes, aryl and substituted aryl; Y is a dihydroxy radical; and n is a number of sufficient value that the average molecular weight of the resulting silicone copolymer is between about 2,000 and 250,000. Examples of copolymers include those wherein R and R' are alkyl groups such as methyl and Y is a biphenol such as 2,2-bis-(4-hydroxy phenyl)-propane, one preferred material being a methyl octyl siloxane 2,2-bis-(4-hydroxy phenyl)-propane copolymer.

Abstract: This invention relates to an electrophotographic imaging member or device and an imaging method using this imaging member, which member or device is comprised of a substrate, a layer of a charge carrier injecting material comprised of carbon or graphite dispersed in a polymer, a layer of a charge carrier transport material, a layer of a photoconductive charge carrier generating material and an electrically insulating overcoating layer.

Abstract: Process for eliminating the need for a separate cleaning station in a one-cycle electrophotographic document copier machine of the transfer type. A backcharge corona generator is added to provide an overcharge/backcharge process to obtain the desired level of charge on the photoconductive system prior to exposure of the photoreceptor to the subject. In that manner, residual toner remaining on the photoconductor after production of the previous copy is cleaned simultaneously with the development of the succeeding copy.

Abstract: In an electrostatic xerographic copying process and apparatus in which a photoconductive insulating master is sensitized by application of a uniform electrostatic charge to the photoresponsive surface thereof, the charge is removed in non-image areas by exposure to a light image corresponding to the non-image areas of an illuminated original to leave charged latent image areas capable of development with coloring material. The sensitized photoreceptive surface is pre-exposed to an electroluminescent element of sufficient intensity to completely or partially remove the charge from all areas or some areas of the surface prior to the exposure to the light image. Complete removal of the charge is advantageous in spaced transverse portions of a continuous master which are not to be exposed to the illuminated original sheet, thereby desensitizing such areas.

Abstract: The duplex copying of two-sided originals onto two sides of a copy sheet is accomplished by interspersing images from two successive documents on a multi-image imaging member, specifically with the front-side image of a second document interspersed between the front and rear-side images of a first document. Copy sheet turnover can thus occur during the transfer of the front-side of the second document to achieve an increased "copy-output-rate to electrographic-procedure-speed" ratio.

Abstract: An improved heat-developable photosensitive material is disclosed which comprises an infrared rays-absorbing layer provided in contact with or adjacent to a layer comprising a reducible organic silver salt.

Abstract: My invention comprises an improved method of electrophotography which enables me to increase the effective speed of a photoconductor. The speed at which copies may be made is a function of the quantum of light falling on the photoconductive surface and the conductivity of the photoconductor under illumination. Since the rate at which a given photoconductor discharges the surface potential on the photoconductor through the action of light is limited, speed can be increased for a given photoconductor only by increasing the illumination. This requires energy and produces heat. My process deliberately underexposes a charged photoconductor to a light and shade image of the original to produce a weak latent electrostatic image of low contrast which is insufficient to make a satisfactory copy. I then mask the latent image with a liquid-carried toner while preventing deposition of the toner on the background areas. I then discharge the background areas with a blanket illumination of low intensity.

Abstract: The image density adjustment method for use in electrophotography in which, when the image density of a copied image is decreased below a standard image density, the development bias-potenial is increased while the exposure to be applied to a photoconductor is kept constant. When the image density of a copied image is increased above the standard image density, the exposure is decreased while the development bias voltage is kept constant. Thus, the image density of a copied image can be adjusted as desired to minimize the effect of light fatigue of the photoconductor.

Abstract: An electrophotographic photosensitive member comprises a base, a photoconductive layer and an insulating layer, and the photoconductive layer contains an intermediate layer formed at the base side of the photoconductive layer. The intermediate layer facilitates injection of electric charge.

Abstract: Positive form overlays are used to make composite images with a positive mode xerographic printer having a laser scan exposure mechanism. The laser scan or electronic exposure mechanism uses an oscillating galvanometer mirror to sweep a scanning spot over a cylindrical shape photoconductor. The xerographic processor includes a transfer drum able to recycle a sheet relative to the photoconductor to transfer at least two sequentially generated xerographic toner images to the same side of the same support in registration. One image is made in response to electronic signals and the other from the positive overlay thereby yielding a composite toner image.

Abstract: A dry electrostatic developer mix having improved fatigue-resistance properties, is realized by adding to the developer mix, which contains carrier particles and pigmented toner particles, molybdenum disulfide in amounts ranging from about 0.005% to about 1.0% preferably in the range of from about 0.009% to about 0.2% based on the weight of carrier particles present in the developer mixture.

Abstract: This specification discloses a method of and an apparatus for controlling electrophotographic images comprising the steps of detecting the contrast voltage between the surface potentials of the light and dark regions of an electrostatic image formed by the electrophotographic image formation process by taking the difference therebetween, modifying the charging conditions so that the detected contrast may assume a predetermined value, and realizing the substantial background region potential at a predetermined level which would not create fog when said electrostatic image is developed into a visible image, substantially without varying the modified contrast.

Abstract: A process is disclosed for increasing the radiation sensitivity of a layer containing a polyacetylenic material while at the same time extending its radiation sensitivity towards longer wavelengths. The process comprises applying a substantially uniform electric field across the polyacetylenic containing layer and imagewise exposing the layer while the electric field is uniformly applied. Novel elements capable of recording images from two different portions of the electromagnetic spectrum are also disclosed.

Abstract: A device for electrophotographically copying wherein for writing a charge pattern into a suitable photo-conductive layer with differing electron mobility and hole mobility a relatively long wave length of light is used which has a penetration depth comparable with the thickness of the layer and which has a quantum energy which corresponds to the energy of deep traps for the less mobile kind of charge carriers. Due to the long life of the charge carriers in the deep traps, the newly applied charges of opposite polarity remain on the exposed locations for a relatively long time since the charge has been caught in the traps whereas the unexposed locations are repeatedly charged again to maintain an undisturbed potential such that the charge pattern is retained for a longer time even with continued exterior charging.

Abstract: The present invention provides an electrophotographic process for producing copied images by repeating the respective steps of at least charging a layered photoconductor having a carrier generation layer and a carrier transport layer, in that order, on a light-transmissible electroconductive support, effecting image-wise exposure by way of one side of said layered photoconductor and developing subsequent thereto, in which the occurrence of stains on the ground of the image is minimized by uniformly applying light in an amount of exposure sufficient for substantially eliminating the residual potential resulting from said image-wise exposure by way of the other side of the layered photoconductor either simultaneously with the image-wise exposure or in the course of from the image-wise exposure to the development.

Abstract: A photo-sensitive screen for producing an electrostatic latent image of an original to be copied is of multi-layer structure having an apertured region in which fine apertures are formed in uniform distribution and including a photo-conductive insulative layer, an electrically conductive substrate, an insulating layer and an electrically conductive layer superposed upon one another in this order, wherein a solid region having no apertures is formed outside of the apertured region for allowing an electrode to be secured thereon in electrical contact with the electrically conductive layer. The electrode serves for applying a bias voltage to the electrically conductive layer for establishing electric field of a predetermined profile between the conductive substrate and the conductive layer across the interposed insulating layer.

Abstract: A method and an apparatus for carrying out a kind of trimming operation in electrophotography, wherein a control light of an image region is irradiated onto a photosensitive body through masking members to thereby eliminate electric charge on the photosensitive body and to control the forming region of an electrostatic latent image. The masking members, in their single form, permit the light to pass therethrough, and intercept the same in their overlapped form, polarizing plates being used for the masking members. The latent image formation in the breadthwise direction of the image original is controlled by an overlapping degree of the masking members. The electrostatic latent image formation in the direction perpendicular to the breadthwise direction of the image is controlled by moving the masking members in their overlapped state in synchronism with movement of the photosensitive body, across the light path of the control light in the image region.

Abstract: A solid conducting agent comprising a finely divided inorganic solid acid and at least 0.5% by weight of a protonically conductive solid adsorbed and supported on the finely divided inorganic solid acid.This solid conducting agent is characterized by much reduced humidity dependency of the electric conductivity, and it has a sufficient electric conductivity even under low humidity conditions. An electro-responsive recording material including a layer of this solid conducting agent does not show a tacking phenomenon even under high humidity conditions.

Abstract: An electrophotographic imaging process, wherein the electrically photosensitive particles for the image reproduction consist of a black pigment selected from the series of the anthraquinoid pigments which contain at least 2 anthraquinone radicals or at least 6 condensed rings, of the perylenetetracarboxylic diimides or of the metal complexes of the formula ##STR1## wherein A represents a nitrogen atom or the ##STR2## X represents a hydrogen or halogen atom or an alkyl group of 1 to 6 carbon atoms,Y represents a hydrogen or halogen atom, an alkyl, alkoxy or alkylsulphonyl group of 1 to 6 carbon atoms, a nitro or carbamoyl group, an alkylcarbamoyl or alkoxycarbonyl group of 2 to 6 carbon atoms or an arylcarbamoyl or aryloxycarbonyl group of 7 to 11 carbon atoms.

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.