Abstract: Disclosed is a method for producing an electrophotographic photoreceptor capable of repeated copying without one imagewise exposure for every one copying and which is superior in stability, sensitivity, resolution and tone reproduction. This method comprises converting to an insualtor, by irradiation with energy ray, any selected area of a surface of an electrophotographic photoreceptor comprising a conductive substrate, a carrier generation layer and a carrier transport layer composed mainly of a compound which is converted to an insulator by irradiation with energy ray.

Abstract: An image forming method of the present invention comprises: a first toner image formation process for forming a first toner image by forming, on a latent image carrier, a first latent image which corresponds to a first image and developing the first latent image by a first toner charged to one polarity through a development process selected from normal and reverse development process selected from normal and reverse development processes so as to correspond to the polarity of the first toner; a second toner image formation process for forming a second toner image by forming, on the latent image carrier, a second latent image which correspond to a second image and developing the second latent image by a second toner charged to the other polarity by the other development process while applying a developing bias; and a transfer treatment process for simultaneously transferring said first and second toner images to a transfer medium; wherein said developing bias VB2 satisfies the following equations:.vertline.

Abstract: A method for maintaining a preselected concentrations of first and second charge directors in a toner composition, where such composition is being subjected to a use in which initial concentrations of the first and second charge directors are being depleted.

Abstract: An electrophotographic light-sensitive material is disclosed, which comprises a conductive support having formed thereon, in succession, a charge generating layer and a charge transfer layer, wherein the charge generating layer comprises a binder resin containing therein a positive hole-transferring charge generating pigment and a specific dicyanovinyl compound or coumarin compound. An image forming process using the electrophotographic light-sensitive material is also disclosed.

Abstract: Xeroprinting masters are formed by first forming a toner mask. The mask is used to expose a xeroprinting master material exhibiting persistent conductivity in response to a given wavelength and intensity of radiation. The toner mask can be formed and transferred to the xeroprinting material without fusing. After exposure the masking toner can be cleaned off providing a planographic master. Multicolor images are formed by forming two or more masking images, and transferring them to two or more master surfaces. After irradiation and cleaning each master surface is used as a xeroprinting master for a particular color in a multicolor duplicating system.

Abstract: An electrical image signal is produced by an electrographic process including the steps of forming a differential voltage pattern; developing the voltage pattern with a luminescent toner; exciting the developed image to emit radiation; and photoelectrically detecting the emitted radiation to produce an electrical image signal.

Abstract: An electrical charging system for repeatedly electrically charging a photoconductor layer on an electrical conductor through charging that photoconductor layer, selectively discharging it, providing toner on the layer, and removing the charge image in the photoconductor for each of as many toners as desired for forming a final printed image, followed by using a removal radiation of a shorter wavelength on the photoconductor to avoid long term changes in the photoconductor. A further charging cycle may be used before the next printed image operation begins.

Abstract: The operating latitude of the tri-level xerographic process is improved by replacing the standard DC bias that is applied to one or both of the developer housings in conventional tri-level imaging with a chopped DC (CDC) developer bias. Chopped DC biasing is the alternate application of two discrete bias voltages to a developer stucture in a periodic fashion at a given frequency, with the period of each cycle divided up between the two bias levels at a duty cycle of from 5%-10% or 90%-95% depending upon which of the two developer structures is being biased. In the case of the DAD developer structure the duty cycle of higher of the two biases is 5%-10% and in case of a CAD developer structure the duty cycle of higher of the two biases is 90%-95%.

Abstract: Image creation apparatus operable in a tri-level highlight color imaging or a black monochrome mode. The developer structures are biased in the tri-level mode using a chopped DC bias while in the monochrome black mode only the black developer structure is biased using a standard monochrome bias.

Abstract: A weak electrostatic image on an imaging member is amplified by first toning it with charge injection toner. The imaging member is treated without fusing the toner image to reduce the charge injection inhibiting effect of charge associated with the toner imaging member interface. Subsequently to or simultaneously with said treating step the imaging member is charged positively, which charge injects through the toner to create an amplified electrostatic image that can be toned.

Abstract: Highlight color imaging apparatus wherein tri-level images are created by using a transparency with optical densities suitable for forming a bi-level image having relatively high and intermediate voltage levels. A modulated light source is then employed to form a third voltage level on the imaging surface by reducing the intermediate voltage level to a relatively low residual voltage level.

Abstract: An object of the invention is to provide a copy machine for recording an additional information onto a copy of document without reducing the document original image. The copy machine has a display for indicating the additional information in the proximity of a glass platen for placing the document. The copy machine is adapted to perform copy operation at least two times so as to form both copy images of the document and the additional information on the same copy sheet.

Abstract: An electrophotographic copying process produces a photocopy having a negative image in order to highlight information in a specified area. An original image is radiated onto a photosensitive medium to form a first image. A solid block is formed in the specified area of the first image. The first image is then transferred to blank paper. The original image is then radiated onto the photosensitive medium again and a portion of the image is erased in order to form a second image. The second image is then transferred to the sheet of paper having the first image. The resulting image formed on the sheet of paper includes a highlighted second image formed in the specified area.

Abstract: A method of preparing a permanent photopolymer master with a permanent latent image for use in electrostatic image transfer to a receiving substrate is provided in which the photopolymer master is first flood pre-exposed to increase the resistivity of the entire photopolymer material and then is selectively exposed for a second time to form the permanent latent image in areas of high resistivity and to leave the background areas of the photopolymer with lower resistivity.

Abstract: Xeroprinting is performed without fusing a master toner image. A master toner image is made by conventional electrophotography, for example, by charging, imagewise exposing and applying toner to a photoconductive imaging member to create a first toner image. The first toner image is charged with charges of a first polarity opposite that of the toner image and the member is erased with erase illumination through its base. This creates a toner image with a charge opposite that of the original toner image which is tightly held by opposite charges which have migrated to the portion of the electrophotosensitive member just under the toner. The imaging member is then toned again with toner of the same polarity as the original toner to create a second toner image that overlies the first toner image. The imaging member is again erased through its base, and the second toner image is transferred to a receiving sheet without disturbing the first toner image.

Abstract: Process for preparation of high resolution image exposing imagewise a photopolymerizable element having a removable cover sheet and a conductive support or a temporary support which is replaced by a conductive support, stripping the cover sheet and laminating the imagewise exposed photopolymerizable layer to a second exposed photopolymerizable layer on a temporary support, removing the temporary support, charging electrostatically the exposed photopolymerizable layers, developing, e.g., liquid electrostatic developer or dry toner developer, and optionally transferring the developed image to a receptor surface, e.g., paper. The process is useful in preparing multiple copies in more than one version, e.g., logos, headlines, corrections, etc.

Abstract: The photoconductive layer of an electrophotographic plate, such as used to record radiographic patterns, is overcoated with a thin dielectric layer having luminescing (e.g., fluorescing or phosphorescing) properties. Upon being uniformly charged and imagewise exposed to actinic radiation (i.e. radiation to which the photoconductive layer responds), the resulting charge pattern is developed with toner. The toner-bearing surface of the electrophotographic plate is irradiated with radiation adapted to excite the luminescent overcoat. The toner image serves, in effect, to mask any luminescence by the underlying overcoat, thereby giving rise to a luminescent contrast image which may be recovered by laser scanning or CCD techniques, or photographed directly.

Abstract: A method of making a reproduction copy of an image or a document by electrophotography wherein high print density portions of an original image are developed and transferred onto a recording medium before low print density portions of the original image are developed and transferred onto the recording medium. The original image is multiply scanned under successive, controlled conditions to produce a series of latent images, each of which represents a print density component of the original image. Each latent image is developed and transferred onto the recording medium to produce a composite print density and gradation which closely approaches the print density and gradation of the original document or a predetermined density and gradation.

Abstract: A method for recording a color image having two or more hues is disclosed which comprises exposing to light from one light source a light-sensitive sheet having carried on the surface thereof a mixture containing, as a light-sensitive agent, two or more kinds of photocurable microcapsules which encapsulate different color formers therein and are sensitive to lights of different wave length regions from each other, with changing the exposure amount in conformity with image information to thereby selectively cure the microcapsules, wherein (i) said light-sensitive agent contains at least one kinds of photcurable microcapsules which become soft when light-exposed in an exposure amount more than the exposure amount necessary for photocuring of said one kind of photocurable microcapsules, or (ii) said exposing is carried out using one light source capable of emitting lights of said different wave length regions simultaneously with controlling the exposure amount within plural levels bonded by maximum sensitivity i

Abstract: An image forming method wherein a latent image is formed by subjecting an image retainer having a photoconductive layer to a image exposure, a toner image is formed by developing the latent image with a toner, each the step of forming the latent image and the step of forming the toner image are repeated at least one time, and a plurality of toner images formed on the image retainer to a transfer material. At least one of the toner images is formed with a toner which has a spectral transmissivity as to substantially absorb a visible light but transmit a light having a wavelength of 750 nm or more. The latent image is formed by subjecting the image retainer bearing the toner image to an image exposure with a light containing a wavelength component of 750 nm or more.

Abstract: An improved method and apparatus for use in exposing of photosensitive material to ultraviolet radiation includes a carrier which is a film strip having a photoconductive layer. The film strip is indexed along a path which extends through a linear array of stations. At a charging station an electrostatic charge is applied to the photoconductive layer on the film strip. At an exposing station, the photoconductive layer on the film strip is exposed to a light pattern which forms a reduced size image of an original to thereby render areas of the photoconductive layer conducting. At a developing station, toner particles are electrically attracted to the conducting areas of the photoconductive layer on the film strip. The toner particles are fused to each other and the material of the film strip to form a permanent visible image. The film strip is then indexed to an exposing station where ultraviolet radiation is directed through the film strip to protect an enlarged image onto photosensitive material.

Abstract: An image editing method utilizing an electrophotographic process, which method includes a first charging step of charging a photosensitive medium; a step of projecting an image onto the charged photosensitive medium to form an electrostatic latent image; a first developing step of developing the electrostatic latent image into a first powder image by the use of a first toner material having the same polarity as the charged polarity; a first transferring step of transferring the powder image onto a copying paper; a second charging step of again charging the photosensitive medium to a polarity the same as that of the charge established during the first charging step; a step of radiating rays of light to the charged photosensitive medium to remove the electrostatic charge at a specificed area of the photosensitive medium; a second developing step of developing the specified area of the photosensitive medium by the use of a second toner material different in color from the first toner material to form a second po

Abstract: An electrophotographic printing process is disclosed that comprises the steps of: imagewise exposing a photosensitive means with light of a wavelength at which photochromism occurs, to thereby record the image therein, wherein said photosensitive means has a photosensitive layer formed on a conductive support, said photosensitive layer containing a photochromically sensitive compound that shows photoconductivity when irradiated with light of different wavelengths before and after said photochromism occurs; charging the entire surface of said photosensitive layer; and uniformly exposing said photosensitive means with light of a wavelength at which photochromism does not occur, but at which said photochromically sensitive compound or photoisomeric compound therewith shows photoconductivity, to thereby form the image of a charge pattern on the surface of said photosensitive layer.

Abstract: Image recording method of the present invention comprises the steps of forming electrostatic latent image on a latent image carrier by a latent image forming means, developing the formed electrostatic latent image with toner, and transferring the visualized toner image to a transfer material after repeating at least the developing step plural times, wherein double-element developer formed from mixing toner and magnetic carrier with its density of 4.0 g/cm.sup.3 or less is used in at least the second and the succeeding developing steps among the plural times of the developing steps.

Abstract: An electrographic luminescent amplification process is described which includes the steps of:a. forming a low amplitude differential voltage pattern on a photoconductor;b. developing the low amplitude differential voltage pattern with a luminescent toner to form a luminescent toner image;c. exciting the luminescent toner image to produce emitted radiation;d. exposing a photoconductor to the emitted radiation to produce a high amplitude differential voltage pattern on the photoconductor; ande. developing the high amplitude differential voltage pattern to produce a high density image.

Abstract: A hydroxy arylamine compound is disclosed represented by the formula: ##STR1## wherein: m is 0 or 1,Z is selected from the group consisting of: ##STR2## n is 0 or 1, Ar is selected from the group consisting of: ##STR3## R is selected from the group consisting of --CH.sub.3, --C.sub.2 H.sub.5, --C.sub.3 H.sub.7, and --C.sub.4 H.sub.9,Ar' is selected from the group consisting of: ##STR4## X is selected from the group consisting of: ##STR5## s is 0, 1 or 2, the dihydroxy arylamine compound being free of any direct conjugation between the --OH groups and the nearest nitrogen atom through one or more aromatic rings. The dihydroxy arylamine compound may be employed in an electrophotographic imaging member and the member may be used in an electrophotographic imaging process.

Abstract: A first developing device is provided in a demountable manner near a photoconductor drum of an electrophotographic copying apparatus. There is further provided a second developing device most downstream along a direction of rotation of the photoconductor drum. Developer containing color toner is stored in the first developing device and developer containing black toner is stored in the second developing device. An outline image forming unit for forming an outline image can be installed in place of the first developing device. When the first developing device is installed, development of a copy image is effected by either the first developing device or the second developing device. When the outline image forming unit is installed in place of the first developing device, an outline image formed by the outline image forming unit is developed by the second developing device.

Abstract: An electrophotographic method is disclosed, in which electrostatic latent images are formed on an electrophotographic photoconductor by exposure of the photoconductor to a light beam, and the formed electrostatic latent images are developed to visible toner images by a developer comprising toner particles, with the minimum diameter D of the light spot of the light beam on the photoconductor and the volume mean diameter X.sub.w of the toner particles being in the relationship of (D).mu.m.gtoreq.9.0.times.(X.sub.w).mu.m-34.

Abstract: A discharging apparatus for use in a copying machine for discharging the photoreceptor layer laminated on a drum includes a short wavelength light source for producing a light having a wavelength shorter than 6000 angstrom, and a long wavelength light source for producing a light having a wavelength longer than 6200 angstrom. A control circuit is provided for controlling both light sources such that both light sources are turned on during at least one complete rotation of the drum before an exposure of a light image on the photoreceptor layer.

Abstract: A combination Xerograhic-DEP printing apparatus wherein highlight color images are formed without scavenging and re-development of a first developed image. A first image is formed in accordance with conventional (i.e. total voltage range available) electrostatic image forming techniques. A successive image is formed on the copy substrate containing the first image subsequent to first image transfer, either before or after fusing, by utilization of direct electrostatic printing.

Abstract: An electrophotosensitive member is uniformly charged and portions to be toned by one type toner are erased. Those portions are filled in with a charge of different potential, for example, a charge of polarity opposite to that of the original charge. The charged member is imagewise exposed and developed with two toners selectively attractive to the different charge potentials. With this method a multicolor image can be formed iwth a single exposure.

Abstract: The invention is an electrophotographic imaging process comprising forming a first electrostatic latent image on an imaging surface of an electrophotographic imaging member comprising an electrophotographic insulating layer and an electrically conductive layer, developing said first electrostatic latent image with a conductive two-component developer having a conductivity between about 10.sup.-10 ohms-cm.sup.-1 and about 10.sup.-14 ohms-cm.sup.

Abstract: An electrophotographic printing machine in which indicia are printed on a sheet in at least two different colors. An electrostatic latent image is recorded on a photoconductive member and developed with a liquid developer material of one color. The latent image is neutralized and ions projected onto the photoconductive member in an image wise pattern to record another latent image. This latent image is developed with a liquid developer of another color. Both liquid images are transferred substantially simultaneously to a sheet to print indicia in two colors thereon.

Abstract: A method of producing an electrostatic charge image comprising the sequential steps of: (1) bringing an electrode into proximity with a photoreceptor, the photoreceptor having a dielectric substrate and a photoconductive film intimately bonded to the substrate, the electrode having means to enable an electric field to be applied across the photoreceptor and being adapted to be brought into proximity with the substrate of the photoreceptor along a length of the electrode and charging the photoreceptor with an electrostatic charge of one polarity and projecting an image of a photograph on the receptor, (2) charging the photoreceptor with an electrostatic charge of opposite polarity, and (3) projecting a photographic image of the subject again on the photoreceptor whereby an electrostatic charge image is formed on the photoconductor surface. The invention also resides in apparatus to carry out the method.

Abstract: An image-forming process using a long rolled transparent light-sensitive recording material is disclosed. The process comprises applying at least two image-forming steps each including at least an image exposure and a development to a long rolled transparent light-sensitive recording material comprising a support having thereon a light-sensitive layer and a surface protective layer containing a hardenable compound and fine particles. The recording material preferably has a backing layer containing fine particles.

Abstract: In an image recording device, particularly suitable for the reproduction of colored images, two images are superimposed on a recording sheet. The second image is so designed that it compensates the undesirable saturation of density under an ordinary condition and that the superimposed image has an improved tone reproduction. The superimposed toner images are heat-fixed together on the print.

Abstract: A control device for a color copier which sets up an adequate color copying time for any particular size of transfer papers. A color document is repeatedly scanned by a scanning optical system to sequentially expose a single photoconductive drum, which is rotated at a constant speed, to a plurality of separated color components. Each of the latent images electrostatically formed on the drum is developed by a toner which is supplied from a developing device and complementary in color to the color component associated with the latent image, the resulting toner images being sequentially transferred to a transfer paper which is held on and rotated together with a transfer drum. The control device includes a paper size setting circuit for setting the size of a transfer paper to be used before a copying operation, a scanning sensor for sensing the start of a scanning performed by the optical system, and a home sensor for sensing the instantaneous angular position of the transfer drum.

Abstract: A method and apparatus for forming an image wherein an image exposure is applied onto a photosensitive member having a member provided with a color separation function, a photoconductive layer and an insulating layer, the photosensitive member subjected to the image exposure is treated for flattening surface potential thereon by using a charging device, a whole surface exposure by light of a specific color is applied to the photosensitive member subjected to the flattening treatment thereby to produce a potential pattern on the photosensitive member at a portion corresponding to the color component provided by color separation, and an image exposure is applied onto the photosensitive member having the potential pattern.

Abstract: In plural-stage liquid development of electrostatic charge patterns, as in multicolor electro-photography, image defects occur in areas of the image which are undeveloped or background areas of a previous development stage. The method of the invention avoids such defects by rinsing the image with a polar liquid between development stages to remove counterions which are believed to cause the defects.

Abstract: A copying apparatus for synthesizing two images on one piece of copying paper. The apparatus includes a photosensitive body having a photosensitive surface, first and second light exposure assemblies disposed in spaced-apart relationship with respect to the path of rotation of the photosensitive surface and an image development assembly. In the first light exposure assembly, a first original positive image source controls light emitted from a first light source which light is transmitted to the photosensitive surface to create a first latent image of the information in the first original positive image source on a first portion of the photosensitive surface. No latent image is formed in the remainder or second portion of the photosensitive surface.

Abstract: A method of reproducing multiplex images wherein an electrostatic image is formed on an image retainer by using a common electrostatic image forming device, the electrostatic image formed on the image retainer is developed, the steps of the above are repeated to superpose a plurality of toner images on the image retainer, and the toner images is transferred on a recording paper by one step. The developings other than the first time developing are carried out in such a manner that the surface of a developer layer on a developer feeding carrier does not contact with the surface of the toner image on the image retainer.

Abstract: The invention provides an electrophotographic method of forming a subsequent toner image overlapping one or more toner images previously formed on a surface of an electrophotographic element.The method comprises the steps of:(a) electrically charging the surface and the previously formed toner image or images,(b) forming an electrostatic latent image overlapping the previously formed toner image or images on the surface by imagewise exposing the element, through the previously formed toner image or images, to actinic radiation of a wavelength outside the range of 400 to 700 nanometers; the density of the previously formed toner image or images to the actinic radiation being less than about 0.2, and(c) electrographically developing the electrostatic latent image to thereby form the subsequent toner image.

Abstract: A record memory medium comprises a recording layer comprising a monomolecular film or monomolecular layer built-up film of a photosensitive organic compound having a hydrophilic moiety and a hydrophobic moiety. The medium can be used for recording/reading-out of information and light recording.

Abstract: The invention disclosed relates to a method of forming composite images. A photosensitive member including an electroconductive base, a photoconductive layer and an insulation layer in a superposed arrangement is used and to this photosensitive member, a negative image is exposed while simultaneously charging, irradiating with light, charging by an a.c. corona charging means and then exposing a positive image to form a composite electrostatic latent image. If the positive image overlaps with the negative image, the positive image is formed in preference.

Abstract: A method of reproducing multiplex images wherein an electrostatic image is formed on an image retainer by using a common electrostatic image forming device, the electrostatic image formed on the image retainer is developed, the steps of the above are repeated to superpose a plurality of toner images on the image retainer, and the toner images is transferred on a recording paper by one step. The developings other than the first time developing are carried out in such a manner that the surface of a developer layer on a developer feeding carrier does not contact with the surface of the toner image on the image retainer.

Abstract: A three-color separation electrophotographic color reproduction process which includes primary uniform charge steps, color separation image exposure steps, development steps and transfer steps. The process further includes between each image exposure step and development step a uniform exposure step and a secondary charge step. The secondary charge step is carried out either by DC corona discharge of the same plurality as the primary charge step or by AC corona discharge together with DC corona discharge. The quantity of light of the uniform exposure step and the quantity of charge of the secondary charge step are controlled, to reduce stepwise, as the second and third primary color reproduction proceeds.

Abstract: The present invention concerns with a method of forming plural copies. The method is constituted by:the first step of charging a photosensitive member,the second step of exposing the charged photosensitive member to an optical image to form an electrostatic latent image,the third step of developing the latent image with a toner,the fourth step of charging the photosensitive member to invert the toner polarity of the developed image,the fifth step of illuminating the photosensitive member charged by the fourth step with light to form the same electrostatic latent image as the latent image formed by the second step,the sixth step of transferring the developed image to copy paper, andthe step of repeating the third step to the sixth step.

Abstract: A two-color copying apparatus has a half reflecting mirror located posterior to an image forming lens in the path of a light beam for splitting a light beam reflected by an original in black and a chromatic color for development of corresponding latent images on respective photoconductive drums and printing on a transfer-printing sheet conveyed by a conveyor belt and successively brought into contact with the outer circumferential surfaces of the drums.

Abstract: The invention relates to a method of forming composite images. After a first electrostatic latent image of positive image is formed on a photosensitive member, a scorotron charger is used to correct the potential of background area to an intermediate potential. Then a second latent image is formed by exposing a negative image to the intermediate potential. This assures production of composite images of high density and good quality free from fog.

Abstract: The invention relates to a method of forming monochromatic or dichromatic copy images with use of a developer composed of a high-resistivity magnetic carrier and a nonmagnetic insulating toner which are triboelectrically chargeable. An electrostatic latent image having at least three different levels of potentials is formed and the toner and carrier are adhered respectively onto first and second image portions.