Abstract: A developing device for a liquid electrophotographic image forming apparatus is provided. The developing device may have a developing roller, which supplies ink to a photosensitive body on which an electrostatic latent image is formed and develops the electrostatic latent image. The apparatus may include an ink reservoir in which ink supplied to the developing roller is accommodated, and an ink removal unit, which removes ink remaining in the ink reservoir after a development operation is performed. The ink removal unit may comprise an ink removal member rotatably installed in the ink reservoir that exhausts ink through a through hole formed under the ink reservoir. A driving member rotates the ink removal member. An ink cartridge stores ink exhausted through the through hole.

Abstract: A liquid developer imaging system comprising a developing container for receiving a quantity of developing solution, a sensing system for maintaining a predetermined processing level of developing solution within the container, a developer roller connected to a first power supply source that biases the developer roller to a development voltage, and a skiving element for plating the developing solution onto the developer roller and scraping excess developing solution from the developer roller to a predetermined thickness, wherein the skiving element is connected to a second power supply source for biasing the skiving element to a skiving voltage, wherein the skiving voltage is greater than the development voltage.

Abstract: A developing device includes: a developer bearing body for bearing liquid developer, the liquid developer bore by the developer bearing body being used by the developing device to develop a latent image bore by an image bearing body; a developer supplying member that has depressions in its surface and whose surface is pressed in contact with the developer bearing body for supplying the liquid developer retained in the depressions to the developer bearing body; and a restricting section for restricting the amount of the liquid developer on the developer supplying member, wherein the amount of the liquid developer, which is retained in the depressions and whose amount has been restricted by the restricting section, before being supplied to the developer bearing body is smaller than the volumetric capacity of the depressions that retain the liquid developer.

Abstract: To remove a carrier liquid from a toner image before transfer on a photosensitive drum, a wet electrophotographic device of the present invention includes a first slit nozzle which blows airflow of a first velocity onto a surface of the photosensitive drum after image formation, a second slit nozzle which is positioned on a downstream side more than the first slit nozzle and which blows airflow of a second velocity higher than that of the airflow supplied from the first slit nozzle onto the surface of the photosensitive drum, and an aperture portion which introduces a reverse airflow generated by the airflow from the second slit nozzle to the first slit nozzle side between both nozzles.

Abstract: An electrophotographic liquid developer includes a carrier liquid and toner particles. The toner particles include a colorant and a resin component and are dispersed in the carrier liquid. The resin component includes a polyester resin as a main component. When 0.3 g of the liquid developer is dropped on a filter paper (which is defined in JIS P 3801) from a point of 10 mm height, the carrier liquid diffuses in the filter paper at a speed not lower than 1 mm/minute.

Abstract: An apparatus prevents developer wraparound in a wet electrophotographic printer using wraparound preventing units. Each of the wraparound preventing units has varied diameter parts formed at both ends of a developing roller, and matching parts formed at both ends of a metering roller to correspond to the varied diameter parts of the developing roller. Since the varied diameter parts and the matching parts are respectively installed at both ends of the developing roller and the metering roller, developer wraparound is not generated in the developing roller and a photosensitive roller during development.

Abstract: A method of preventing a flow pattern in a wet-type color image forming apparatus and a system adopting the same includes a material layer directly contacting a developing roller of a developing unit of a photosensitive body of the image forming apparatus and having a thickness of 7–15 ?m. A size of an essential composition used for representing corresponding one of colors in high-concentration ink is 0.7–1.5 ?m. A hold up volume is not formed between the developing roller and the photosensitive body during a developing process, and a flow pattern such as a stripe, is not formed in a final image, and even though the flow pattern is formed in the final image, the flow pattern can be minimized.

Abstract: A liquid electrophotographic image forming apparatus including a liquid carrier depositing unit that is arranged at a forward direction of the secondary transfer roller at a paper feed path and deposits liquid carrier on a print side of a sheet of paper that is secondarily transferred.

Abstract: Disclosed is a developing unit of a wet electrophotographic printer, which has a photoconductive drum, a developing roller for transferring a developer onto the photoconductive drum, a cartridge for storing a developer therein, a developer guide disposed at a predetermined distance away from an inner wall of the cartridge, and having a developer supplying path defined therein to guide the developer in the cartridge to the developing roller, and a developer pumping means disposed in the cartridge to pump up the developer in the cartridge toward the developing roller.

Abstract: A CPU 113 executes a control program stored in a memory 116 thereby forming a plurality of patch images with a developing bias increased for each of the patch images; detecting a density of each of the patch images by means of a patch sensor 17; and comparing the image densities to determine whether the image density is saturated or not. Then, an image forming condition in which an image density is substantially saturated is determined and is stored in the memory 116. When a print command signal is inputted from an external device via a main controller 100, a printing operation is performed under the image forming condition stored in the memory 116.

Abstract: A developing unit of a liquid electrophotographic image forming apparatus. The developing unit includes a developing roller, which supplies ink to a photosensitive medium on which an electrostatic latent image is formed, to develop the electrostatic latent image. The apparatus also includes an ink storage unit adapted to store ink to be supplied to the developing roller, and an ink cartridge, which is installed in the ink storage unit to be opened or closed and supplies ink to the ink storage unit. The ink cartridge includes a cartridge sleeve rotatably installed, and a cartridge slider, which slides by rotation of the cartridge sleeve to open the ink cartridge.

Abstract: A color printing system comprising a combination of at least four, and preferably six coloring materials, each of a different color, wherein these colors are selected from (1) an orange-red; (2) a violet-red; (3) a violet-blue; (4) a green-blue; (5) a green-yellow; and (6) an orange-yellow; as well as white and black. This system may be incorporated into a wide range of printing devices and provides a means of achieving a wide range of colors.

Abstract: An electrostatic transfer type liquid electrophotographic printer which has a photoreceptor web having a charged surface and opposing back surface, at least one exposing unit for forming a latent electrostatic image onto the charged surface of the photoreceptor web, and at least one development unit for developing the latent electrostatic image on the photoreceptor web into a toner image, wherein each development unit has a developer roller, a toner removal roller, and a squeeze roller, and a backup roller corresponding to at least one of the developer roller, toner removal roller, and squeeze roller, and wherein the photoreceptor web is arranged to provide at least 1 degree of contact wrap around at least one of the backup rollers. The printer further includes an electrostatic transfer unit for transferring the toner images formed in each development unit from the photoreceptor web to a print medium by electrostatic force.

Abstract: A wet electrophotographic image forming machine that informs a user of a timing for replacing development cartridges. The image forming machine comprises a control section for sensing the condition of the developer stored in one or more developer housings on the basis of a measured electric current flowing between one or more developer feeding members and one or more developer application members via the developer provided therebetween, and a display section for externally displaying the developer condition according to a signal from the control section. The control section evaluates the magnitude of the electric current and provides a signal to the control section for display if there is a developer amount or concentration deficiency.

Abstract: An image forming apparatus configured to use a highly viscous, dense developing liquid including a carrier liquid and toner. The apparatus includes a developing unit with a developer carrier and a coating member for coating the developing liquid on the developer carrier. The developer carrier conveys the liquid to a developing zone where it faces an image carrier to develop a latent image on the image carrier. In the developing zone, the toner is caused to move toward the image by electrophoresis to form a toner layer in which the toner is present in the carrier liquid and a carrier layer in which the toner is absent. When the developer carrier and image carrier are moved from each other, the toner moves toward the image such that the developing liquid separates at the boundary between the toner and carrier layers.

Abstract: A liquid developer electrophotographic apparatus and method for developing one or more successive color images on a previous color image formed on a latent image retaining body, wherein peeling off the prior color image is prevented by establishing a reversible electrophoretic transfer efficiency of toner particles in the prior toner image to be not greater than 60% in the liquid developer for the successive color image while applying an electrical potential difference between the latent image retaining body and a developing electrode for the successive developing step(s). A resin content of the toner particles forming the previous color image may be selected to achieve the reversible electrophoretic transfer efficiency of 60% or less.

Abstract: A developing unit maintains constant density in an electrophotographic imaging process. The developing unit has: a) a developer with a developing surface and a first voltage is applied to the developer; b) a depositor, wherein said depositor is positioned to maintain a gap with the developer and a second voltage is applied to the depositor; c) a cleaning device for said developer, wherein the cleaning device is in contact with the developer; and d) an ink container, wherein the developer, the depositor and the cleaning device are inside the ink container.

Abstract: A developing device for developing a latent image formed on an image carrier with a developing liquid includes a liquid storing section for storing the liquid including a developing substance and a carrier liquid. A developer carrier deposits the liquid fed from the liquid storing section thereon. A float type liquid level sensor senses a liquid level in the liquid storing section. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device.

Abstract: An excess toner removal area is made broader over the whole area with respect to a developer applied area that is broader than an image effective area. Thereby a liquid developer, that tends to spread slightly broader than the applied area after being applied to a photoreceptor drum, is removed by a sweep roller that can sweep excess toner present in an area broader than the original applied area and an excess toner remaining area is then prevented from being formed on the photoreceptor drum. Accordingly, the excess toner on the latent image carrier is removed as much as possible, and a transfer medium and peripheral members are prevented from being soiled due to residual excess toner.

Abstract: An apparatus for assisting in the removal or waste or excess ink and a method for disposal of ink from electrophotographic printers comprises providing electrophotographic ink from a source, combining the ink with an absorbable material in a container to form a solid within the container, and closing the container so that the container with the solid inside may be disposed of without ink flowing from the container.

Abstract: A removal nip having a predetermined width is formed by a sweep roller pressurizing mechanism, which adjusts the length of a tension spring by rotating an adjustment screw, and adjusting the size of an energizing force of a sweep roller with respect to a photosensitive drum. A pressurizing mechanism similar to the sweep roller pressurizing mechanism is also provided in a developing roller, to adjust the energizing force of the developing roller, to thereby form a developing nip having a predetermined width.

Abstract: A device for coating a developing liquid included in an developing device of the present invention includes a coating member rotatable with the developing liquid deposited thereon in a preselected amount. An intermediate member has a surface contacting the surface of the coating member and is movable at the same speed and in the same direction as the surface of the coating member. Also, the surface of the intermediate member contacts the surface of a developing roller to be coated with the developing liquid and is movable in the opposite direction to the surface of the developing roller.

Abstract: An image forming apparatus of the present invention having a transferring particle layer forming equipment which forms a transferring particle layer prior to forming a toner layer on a surface of an image recording member, whose coagulation force among the transferring particles in the transferring particle layer is smaller than adhesive force of the transferring particle layer to the image recording member, a development equipment which forms a toner layer on a surface of the image recording member according to image information with a liquid developer in a manner that a part of the toner layer is superimposed on the transferring particle layer and a transfer equipment which transfer the toner layer to a transfer medium together with a part of the transferring particle layer. As a result, high transfer efficiency can be obtained, and an image forming apparatus which realizes high image quality is provided.

Abstract: A wet electrophotographic printer includes a developing chamber communicating with an inlet of a first nip between a developing roller and a deposit roller to supply a liquid developer into the first nip therebetween, a developer storing chamber communicating with an inlet of a second nip between the developing roller and a metering roller to withdraw the liquid developer of a low density generated at the second nip during a development, and preventing the liquid developer of the low density from being supplied to the first nip, and a developer supply unit disposed below a partition to supply the liquid developer from the developer storing chamber into the developing chamber. The liquid developer of the low density generated at the second nip is not directly supplied to the first nip, but is supplied after being withdrawn to the developer storing chamber and mixed therein.

Abstract: Hard imaging device vapor removal systems, hard imaging devices, and hard imaging methods are described. According to one embodiment, a hard imaging device vapor removal system includes a supply path configured to supply air to an imaging region of a hard imaging device configured to use a liquid ink marking agent to form a plurality of hard images using media, wherein the air of the supply path is supplied to remove a carrier vapor of the liquid ink marking agent resulting from imaging operations of the hard imaging device, an exhaust path configured to remove at least some of the carrier vapor externally of the imaging region using the supplied air, and a bypass path configured to supply supplemental air to the supplied air exhausting the carrier vapor of the liquid ink marking agent.

Abstract: An apparatus for assisting in the removal or waste or excess ink and a method for disposal of ink from electrophotographic printers comprises providing electrophotographic ink from a source, combining the ink with an absorbable material in a container to form a solid within the container, and closing the container so that the container with the solid inside may be disposed of without ink flowing from the container.

Abstract: A developing unit includes a developing roller including a roller portion. The developing roller is rotatable while carrying a developing liquid on the roller portion. The developing unit also includes a voltage applying device that applies a voltage to the roller portion to form an electric field for development between the roller portion and an image carrier, whereby the developing liquid deposited on the roller portion is transferred to a latent image formed on the image carrier. The roller portion includes a volume resistivity ranging from 0 ?·cm to 107 ?·cm.

Abstract: An image-bearing article used in liquid contact electrostatic printing (CEP) is formed from polymers that meet the requisite conformance and heat stability for the CEP process. Excessive absorption of toner carrier liquids by the image-bearing article in liquid CEP leads to the deterioration of the image-bearing article and reduces the useful life of the image-bearing article. The absorption of the toner carrier fluid may be controlled by the addition of oxides, silicone elastomers containing phenyl end groups, fluorosilicones or increasing the cross-linking density of the methyl silicones.

Abstract: A liquid-development electrophotographic apparatus forms on a toner-image-bearing body a plurality of color images developed by a plurality of developing units, one for each color, that use liquid toner. One or more carrier-removing units for removing excessive carrier from a toner layer that forms a toner image are disposed downstream of each developing unit and upstream of the next developing unit disposed upstream of the former developing unit with respect to a process progress direction. Each carrier-removing unit includes two or more conductive collection rollers to which a bias voltage is applied in such a direction as to press toner against the toner-image-bearing body and which is brought into contact with the toner-image-bearing body. The upstream roller is rotated in the same direction as the direction of surface movement of the toner-image-bearing body, whereas the downstream roller is rotated in the opposite direction.

Abstract: A liquid developer which includes an insulating liquid, and toner fine particles containing a coloring agent and a toner resin. In the liquid developer, its electric capacitance does not significantly vary in an electric circuit where an electrical double-layer capacitor and an electronic resistance corresponding to a velocity of an electron exchange during an electrode reaction are connected in parallel, and a resistance corresponding to an electric conductivity of the insulating liquid is connected in series. The coloring agent has a coating layer so as to maintain distances between the toner fine particles. The insulating liquid has a viscosity of 0.5 mPa·s to 1000 mPa·s, a specific resistance of 1×1012 ?cm or more, and a surface tension of 30 dyn/cm or less, and may be a nonvolatile liquid having a boiling point of 100° C. or higher.

Abstract: A method for developing a latent image formed on an image carrier with a developing liquid includes storing a liquid consisting of a developing substance and a carrier liquid developing and sensing the liquid fed from the liquid storing section thereon and sensing a liquid level in the liquid storing section using a liquid level sensor. The liquid level sensor includes a magnetic force generating member for generating a magnetic force, a magnetic force sensing device for sensing the magnetic force, and floats movable up and down in accordance with the liquid level in the liquid storing section. A distance between the magnetic force generating member and the magnetic force sensing device varies in accordance with the movement of the floats, allowing the liquid level to be determined on the basis of the output of the magnetic force sensing device. An image forming method including a developing device is also disclosed.

Abstract: A device for coating a developing liquid included in an developing device of the present invention includes a coating member rotatable with the developing liquid deposited thereon in a preselected amount. An intermediate member has a surface contacting the surface of the coating member and is movable at the same speed and in the same direction as the surface of the coating member. Also, the surface of the intermediate member contacts the surface of a developing roller to be coated with the developing liquid and is movable in the opposite direction to the surface of the developing roller.

Abstract: An image forming apparatus using a highly viscous, dense developing liquid consisting of a carrier liquid and toner. A developing unit including a developer carrier and a coating member for coating the developing liquid on the developer carrier. The developer carrier conveys the liquid to a developing zone to develop a latent image formed on the image carrier with the liquid. In the developing zone, the toner in the liquid is moved toward the image by electrophoresis to form a toner layer in which the toner is present in the earner liquid and a carrier layer in which the toner is absent in the same. When the developer carrier and image carrier are moved away from the developing zone, the toner is moved toward the image over a degree at which the developing liquid can separate at the boundary between the toner layer and the carrier layer.

Abstract: A liquid image developing system, including a cartridge in which a developer is stored; a supply line; a development container to which the developer is supplied from the cartridge through the supply line; a photosensitive body in the development container; a development roller partially soaked in the developer in the development container and rotating opposite to the photosensitive body; a depositing member to create a potential difference required to attach the developer to a circumference of the development roller, opposite to the development roller; a metering blade to scratch the developer attached to the circumference of the development roller to a predetermined thickness; and an agitator to agitate the developer contained in the development container. Accordingly, a high-concentration developer can be directly used in the development operation without a dilution operation, and thus the structure to supply the developer can be considerably simplified.

Abstract: A system and method for recycling used hydrocarbon-based carrier liquid removes contaminants from the used carrier liquid and monitors an electrical property of the output carrier liquid so that the carrier liquid can be reused in a predefined application, such as an electrostatic imaging process. The system and method may be integrated into an electrostatic imaging machine.

Abstract: A liquid image developing system includes a development container to store a developer; a photosensitive body; a development roller partially soaked in the developer in the development container and to rotate opposite to the photosensitive body; a metering blade to scratch the developer attached to a circumference of the development roller to a predetermined thickness; a depositing plate spaced from the development roller to form a space therebetween; a supplying portion to supply the developer to the space between the development roller and the depositing plate; and a power supply to apply a voltage to the depositing plate so that the developer is transferred to the development roller from the space by an electric force. Accordingly, a high-concentration developer can be directly used in the development operation without a dilution operation, and thus the structure to supply the developer can be considerably simplified.

Abstract: A developing unit using a high concentration ink includes a developing solution supply unit supplying the developing solution containing the high concentration ink, a developing roller, whose lower half is soaked in the developing solution of the developing solution supply unit, absorbing the developing solution by a surface tension, and a photosensitive drum contacting the developing roller, receiving the developing solution absorbed on a surface of the developing roller and developing a latent electrostatic image formed on a surface of the photosensitive drum. Accordingly, as much as about 100% of a binary ink development (BID) is achieved, thereby providing a high quality image.

Abstract: An electrode module in the form of a flexible sheet which contacts with a toner layer and to which a bias voltage is applied is provided on a developing roller before development. The electrode module is adapted to separate the toner layer largely into a toner-rich layer and a carrier-rich layer by utilizing electrical migration occurring in the toner layer when an electric field is applied to the toner layer on the basis of the bias voltage. The electrode module is constructed in such a manner that the sheet is pulled toward a surface of the developer bearer body by a force attributable to surface tension or wetting characteristic of the liquid developer existing between the sheet and the developer carrying body, whereby the sheet comes into contact with the surface of the developer bearer body. This electrode construction increases the contact area or nip width of a bias blade provided for the developing roller and enhances its contact stability.

Abstract: Disclosed is a developing unit of a wet electrophotographic printer, which has a photoconductive drum, a developing roller for transferring a developer onto the photoconductive drum, a cartridge for storing a developer therein, a developer guide disposed at a predetermined distance away from an inner wall of the cartridge, and having a developer supplying path defined therein to guide the developer in the cartridge to the developing roller, and a developer pumping means disposed in the cartridge to pump up the developer in the cartridge toward the developing roller.

Abstract: A liquid electrophotographic image forming apparatus including a liquid carrier depositing unit that is arranged at a forward direction of the secondary transfer roller at a paper feed path and deposits liquid carrier on a print side of a sheet of paper that is secondarily transferred.

Abstract: An excess toner removal area is made broader over the whole area with respect to a developer applied area that is broader than an image effective area. Thereby a liquid developer, that tends to spread slightly broader than the applied area after being applied to a photoreceptor drum, is removed by a sweep roller that can sweep excess toner present in an area broader than the original applied area and an excess toner remaining area is then prevented from being formed on the photoreceptor drum. Accordingly, the excess toner on the latent image carrier is removed as much as possible, and a transfer medium and peripheral members are prevented from being soiled due to residual excess toner.

Abstract: A developer, for an electrophotographic image forming system, includes a developer container for storing developing solution, a developing roller which is partially soaked in the developing solution stored in the developer container and installed to rotate in an opposite direction of a photosensitive medium, a cleaning roller, which is soaked in the developing solution, is installed to rotate opposite to the developing roller and removes the developing solution remaining on the surface of the developing roller, and a developing solution agitator, which agitates the developing solution, and thereby keeps the developing solution in uniform concentration.

Abstract: A developing unit of a liquid electrophotographic image forming apparatus. The developing unit includes a developing roller, which supplies ink to a photosensitive medium on which an electrostatic latent image is formed, to develop the electrostatic latent image. The apparatus also includes an ink storage unit adapted to store ink to be supplied to the developing roller, and an ink cartridge, which is installed in the ink storage unit to be opened or closed and supplies ink to the ink storage unit. The ink cartridge includes a cartridge sleeve rotatably installed, and a cartridge slider, which slides by rotation of the cartridge sleeve to open the ink cartridge.

Abstract: The electrophotographic apparatus of an embodiment of the present invention is an elelctrophotographic apparatus having an electrostatic latent image holding device, an image forming device which forms an electrostatic latent image on the latent image holding device and developing the electrostatic latent image by a liquid developer having a carrier liquid and toner particles dispersed in the carrier liquid, a cabinet for housing the electrostatic latent image holding device and image forming device, and a carrier liquid removal device for removing a carrier liquid evaporation component vaporized and generated in the cabinet and the carrier liquid removal device has an atomizer for spraying a cyclodextrin solution into gas containing the aforementioned carrier liquid evaporation component as a removal agent for removing the carrier liquid evaporation component.

Abstract: A removal nip having a predetermined width is formed by a sweep roller pressurizing mechanism, which adjusts the length of a tension spring by rotating an adjustment screw, and adjusting the size of an energizing force of a sweep roller with respect to a photosensitive drum. A pressurizing mechanism similar to the sweep roller pressurizing mechanism is also provided in a developing roller, to adjust the energizing force of the developing roller, to thereby form a developing nip having a predetermined width.

Abstract: A developer unit for a wet-type color image forming apparatus. The developer unit includes a developer bath filled with a liquid developing agent to a predetermined depth, and a developing roller that develops an electrostatic latent image formed on a photoreceptor to correspond to an original image by supplying the liquid developing agent while being partially immersed in the liquid developing agent. The developer unit further includes a cleaning roller that cleans the surface of the developing roller, a depositing roller that deposits the liquid developing agent onto the cleaned surface of the developing roller, and a metering roller that adjusts the thickness and concentration of the liquid developing agent deposited onto the surface of the developing roller by the depositing roller to suitable levels to develop the electrostatic latent image. The developer unit also includes a developer cartridge that supplies the liquid developing agent into the developer bath.

Abstract: An image-bearing article used in liquid contact electrostatic printing (CEP) is formed from polymers that meet the requisite conformance and heat stability for the CEP process. Excessive absorption of toner carrier liquids by the image-bearing article in liquid CEP leads to the deterioration of the image-bearing article and reduces the useful life of the image-bearing article. The absorption of the toner carrier fluid may be controlled by the addition of oxides, silicone elastomers containing phenyl end groups, fluorosilicones or increasing the cross-linking density of the methyl silicones.

Abstract: An image forming apparatus of the present invention uses a highly viscous, dense developing liquid consisting of a carrier liquid and toner dispersed therein. A developing unit includes a developer carrier and a coating member for coating the developing liquid on the developer carrier. The developer carrier conveys the liquid to a developing zone where it faces an image carrier to thereby develop a latent image formed on the image carrier with the liquid. In the developing zone, the toner in the liquid, which faces the image of the image carrier, is caused to move toward the image by electrophoresis to thereby form a toner layer in which the toner is present in the carrier liquid and a carrier layer in which the toner is absent in the same. When the developer carrier and image carrier moved away from the developing zone part from each other, the toner is caused to move toward the image over a degree at which the developing liquid can separate at the boundary between the toner layer and the carrier layer.

Abstract: There is described an applicator element for providing a layer of a liquid ink, in particular for inking a latent image carrier of a device for electrographic printing or copying, the surface of the applicator element having a structure with a plurality of areas at which the detachment of droplets from the liquid layer is facilitated.

Abstract: A liquid developer electrophotographic apparatus and method for developing one or more successive color images on a previous color image formed on a latent image retaining body, wherein peeling off the prior color image is prevented by establishing a reversible electrophoretic transfer efficiency of toner particles in the prior toner image to be not greater than 60% in the liquid developer for the successive color image while applying an electrical potential difference between the latent image retaining body and a developing electrode for the successive developing step(s). A resin content of the toner particles forming the previous color image may be selected to achieve the reversible electrophoretic transfer efficiency of 60% or less.