Abstract: A developing device comprises a latent image carrier that carries a latent image, a toner carrier opposing the latent image carrier while carrying toner to develop the latent image, and plural electrodes arranged in a prescribed direction insulated from each other on the surface of the toner carrier to create an electric field therebetween. An alternating voltage supplying device is provided to supply n number of phases (n ?2) of an alternating voltage to the plural electrodes, respectively. The alternating voltage changes the electric field to cause the toner to hop and form toner cloud on the surface of the toner carrier. The toner hopping is halted at a prescribed time period during the toner cloud formation.

Abstract: A developing device includes a toner carrying member and an electric-field forming unit. The electric-field forming unit forms electric fields having different characteristics at a first area of the surface of the toner carrying member located within a developing area and a second area of the surface of the toner carrying member located out of the developing area such that a hopping height of toner at the first area is higher than that at the second area.

Abstract: A developing device include: a toner carrier that is arranged oppositely to an image carrier; a toner-flying electrode member spaced apart from the toner carrier; and an oscillating electric field generating power source that connects the toner-flying electrode member and the toner carrier, and generates an oscillating electric field which causes the toner to fly from the toner carrier. The toner-flying electrode member includes a conductive member that extends at least along a rotational axis direction of the toner carrier; an insulating coating layer that applies insulating coating continuously to a conductive member surface located on a toner carrier side; and an exposed portion where the conductive member surface adjacent to the insulating coating layer and located on an image carrier side is exposed.

Abstract: A marking apparatus including a traveling wave grid toner transport circuit structure for transporting powdered toner along a transport surface, and electromechanical elements for selectively enabling toner patches to be projected to an output medium by a projecting electric field.

Abstract: A development device includes a toner carrier including first and second groups of electrodes, a toner supplier, and an electrical field generator to generate an electrical field for causing toner to hop along the surface of the toner carrier. The electrical field generator includes a positive-phase pulse voltage generation circuit, a negative-phase pulse voltage generation circuit, a first DC power source for supplying a bias for setting a peak value of pulse voltages, a second DC power source to output a variable voltage having a polarity identical to a polarity of toner charge, a first diode having an anode and a cathode connected to a lower potential side of the positive-phase pulse voltage generation circuit and an output terminal thereof, and a second diode having an anode and a cathode connected to the lower potential side of the positive-phase pulse voltage generation circuit and an output terminal thereof.

Abstract: A marking apparatus including a traveling wave grid toner transport circuit structure for transporting powdered toner along a transport surface, and electric field concentrating elements for selectively enabling toner patches to be projected to an output medium by a projecting electric field.

Abstract: A toner supply apparatus 6 is configured to be able to supply a charged toner T to a latent image forming surface LS of a photoconductor drum 3. The toner supply apparatus 6 houses a toner electric field transport body 62. The toner electric field transport body 62 has first portions and second portions which differ in toner T transport force. The first portions and the second portions differ in structural feature, such as relative dielectric constant or thickness. By means of such a structural difference, the state of transport of the toner T on the toner transport surface TTS is appropriately set.

Abstract: Exemplary embodiments provide a direct imaging system and methods for direct marking an image using the system. The disclosed direct imaging system can eliminate the creation of a latent image and can be used in an electrophotographic machine and related processes. Specifically, the direct imaging system can include a direct marking substrate (e.g., a printing substrate) and a development belt member closely spaced from the direct marking substrate. In one embodiment, the development belt member can include a plurality of actuator cells with each actuator cell controllably addressable to eject one or more toner particles adhered thereto. The ejected toner particles can transit the space between the donor belt member and the direct marking substrate, and directly marking onto the direct marking substrate forming an image.

Abstract: A development device provided with a first electrode layer and a second electrode layer, which are laminated so as to overlap one another in a normal direction with respect to the surface of the roller part of the toner bearing roller. A plurality of openings are provided in the second electrode layer, over the entire latent image bearable area of a photosensitive body in the orthogonal-to-movement direction. The toner on the surface of the roller part is caused to hop between a plurality of spots directly beneath the openings that respectively exist directly beneath the plurality of openings in the second electrode layer, and a plurality of spots between the openings that respectively exist between the plurality of openings in the second electrode layer, within the entire area of the first electrode layer which is uniformly formed in the roller circumferential direction.

Abstract: A developing device for a toner powder cloud development system, which can achieve high image quality and can be made compact. The developing device has a two-component development unit, a toner carrier, and an alternating current power source. The toner carrier, which is arranged opposing a latent image carrier, has a plurality of electrodes disposed in a line in a prescribed direction on the surface thereof, and mutually insulated. The alternating current power source supplies a voltage such that an electric field across the plurality of electrodes is temporally switched. The inter-electrode electric field causes the toner being carried on the surface of the toner carrier to carry out hopping, thereby forming a toner powder cloud and carrying out development. The movement speed of the latent image carrier and the linear velocity of the toner carrier are set at approximately equivalent speeds.

Abstract: An apparatus for developing a latent image on a latent image carrier includes a toner carrier and multiple electrodes arranged at intervals on a surface of the toner carrier. A potential difference is formed between even-numbered electrodes and odd-numbered electrodes of the electrodes by applying a first pulse voltage to the even-numbered electrodes and a second pulse voltage to the odd-numbered electrodes so that toner on the surface of the toner carrier moves back and forth between the electrodes, where the first and second pulse voltages are in different phases, and the toner moving back and forth between the electrodes is conveyed to a position facing the latent image carrier by movement of the surface of the toner carrier and thereby caused to adhere to the latent image on the latent image carrier.

Abstract: The present invention is directed to a non-contact, single-component developing system for electrophotographic devices that enables high speed, high quality development and color development without an accumulator, or some other intermediate transfer member by employing a plurality of ancillary developing members operating in tandem with a toner-carrying member to facilitate toner detachment from the toner-carrying member. The developing system of the present invention utilizes high electrostatic forces to enable toner jump without AC voltages and exploits toner adhesion forces adhering toner particles to a surface (e.g., a latent image-bearing member) to facilitate high speed development.

Abstract: A toner supply apparatus 6 is configured to be able to supply a charged toner T to a latent image forming surface LS of a photoconductor drum 3. The toner supply apparatus 6 houses a toner electric field transport body 62. The toner electric field transport body 62 has first portions and second portions which differ in toner T transport force. The first portions and the second portions differ in structural feature, such as relative dielectric constant or thickness. By means of such a structural difference, the state of transport of the toner T on the toner transport surface TTS is appropriately set.

Abstract: Exemplary embodiments provide a digital development system and methods for making and using the system. Specifically, the digital development system can utilize a roll member that includes a plurality of actuator cells arranged in a 2-dimensional array with each actuator cell having an actuator membrane individually addressable to eject one or more toner particles adhered thereto. In addition, the digital development system can utilize an imager architecture that includes an addressing logic circuit connected to each cell to selectively control the ejection of the one or more toner particles onto an image receiving member that is closely spaced from each actuator membrane. The disclosed digital development system can be used for non-interactive development systems for image-on-image full-color printing similar to HSD (Hybrid Scavengeless Development) technology with the donor roll becoming a high quality silent imager.

Abstract: Exemplary embodiments provide a direct imaging system and methods for direct marking an image using the system. The disclosed direct imaging system can eliminate the use of at least one of a charge, and/or exposure subsystems in an electrostatographic machine and related processes. Specifically, the direct imaging system can include a direct marking substrate (e.g., a printing substrate) and a development roll member closely spaced from the direct marking substrate. In one embodiment, the development roll member can include a plurality of actuator cells with each actuator cell controllably addressable to eject one or more toner particles adhered thereto. The ejected toner particles can transit the space between the donor roll member and the direct marking substrate, and thereby marking onto the direct marking substrate forming an image.

Abstract: A toner bearing member is provided which includes a conductive support, an insulation layer provided on the conductive support, multiple electrodes arranged at regular intervals on the insulation layer, a surface layer covering the multiple electrodes, comprising a polymerized compound having a specific unit, and a voltage applicator that applies a voltage between the conductive support and the multiple electrodes while periodically reversing an electric field generated therebetween.

Abstract: An image forming apparatus including: an image bearing member; and a developer bearing member bearing a developer including a toner and a carrier, the developer bearing member developing an electrostatic image formed on the image bearing member with the developer, and the developer bearing member being applied with an alternate voltage in order to form an alternate electric field between the developer bearing member and the image bearing member, wherein assuming that electric field intensities Eb and Ed be Eb=|(Vp1?VL)/D| and Ed=|(Vp2?VL)/D|, a relationship, 0?K1>K2, is satisfied, where K1: a gradient at Ed, and K2: a gradient at Eb, and wherein a resistivity ?b of the carrier at the electric field intensity Eb satisfies 1.1×106×en<?b<6.0×107 [?·m] (where: e is the base of natural logarithms; and n=4×Eb×10?7).

Abstract: A developing apparatus is accommodated within a laser printer. The developing apparatus includes a developing casing and a toner electric field transport body. The toner electric field transport body includes a transport wiring substrate and a transport-substrate support member. A plurality of transport electrodes are provided on the transport wiring substrate. The transport wiring substrate is supported by the transport-substrate support member in a state in which the transport wiring substrate is deformed in a tubular shape. Further, the transport wiring substrate is supported by the transport-substrate support member such that margin areas of the transport wiring substrate, which are opposite end portions of the transport wiring substrate with respect to a sub-scanning direction and in which the transport electrodes are not formed, are separated from a tonner transport path.

Abstract: A development apparatus using a hopping method and an image formation apparatus including the development apparatus are disclosed. The development apparatus includes a toner supporting object for supporting and conveying a toner by a movement of the toner supporting object, while the toner is hopping on a surface of the toner supporting object by an electric field; a regulating member made of a flexible material for constituting a toner thickness regulation position; a latent image supporting object for supporting a latent image; and a development position, which is a position of the toner supporting object, that counters the latent image supporting object; wherein the toner is conveyed through the regulation position to the development position where the toner is adhered to the latent image, and wherein one end of the regulating member is supported, and the other end contacts the toner supporting object.

Abstract: An image creating apparatus includes a casing that stores therein an agent, an agent carrier rotatably supported by the casing, a hole defining member defining a plurality of holes therein and opposed to the agent carrier, a plurality of spray electrodes provided on the hole defining member respectively corresponding to the holes and forming an electric field for selectively causing the agent to be sprayed from the agent carrier towards the holes, and a positioning member provided on the casing to cover the agent carrier and positioning the hole defining member with respect to the agent carrier so that the agent carrier and the hole defining member are in a predetermined positional relationship. The angle of the positioning member is adjustable relative to the casing about a rotation shaft that is coaxial with the agent carrier.

Abstract: Each transport electrode has its longitudinal direction intersecting with a sub-scanning direction. Transport electrodes 133a are disposed in parallel with each other and are arrayed along the sub-scanning direction. A transport-electrode electricity supply wiring section is connected to root portions of the transport electrodes. The root portions are one end portions of the transport electrodes with respect to the longitudinal direction. Toner transport guide members are disposed in such a manner as to cover the transport-electrode electricity supply wiring section and opposite end portions of the transport electrodes; i.e., the root portions and distal end portions.

Abstract: A developer supply device carrying charged developer along a developer carrying path to a supply target, including: a carrying substrate that includes a plurality of carrying electrodes arranged along the developer carrying path and is configured to carry the developer through an electric field generated by voltage application to the plurality of carrying electrodes. The carrying substrate comprises a vertical carrying substrate provided to stand to carry the developer upward in a substantially vertical direction. The developer is supplied to the supply target around an upper end portion of the vertical carrying substrate.

Abstract: A Hybrid Scavengeless Development electrophotographic printing system is provided wherein the electrode wires contain carbon nanotube yarn. The use of carbon nanotube yarn alleviates the problem of fundamental strobing image defects, because the electrodes made from the carbon nanotube yarn can be put at a higher tension to density set point, and thereby achieve fundamental resonance frequencies larger than that obtainable from steel. Additionally the yarn's strength is sufficient to withstand the typical forces it is subjected to in a Hybrid Scavengeless Development environment.

Abstract: A disclosed development device includes: a latent image carrier; a conveying member disposed so as to face the latent image carrier, the conveying member having plural electrodes insulated from one another and arranged at predetermined intervals so as to generate an electric field for moving toner on the conveying member; a voltage application unit applying a voltage of n phases (n is a positive integer not less than one) to the electrodes so as to form a cloud of the toner and the toner is adhered to the latent image carrier so as to form a visualized toner image; a toner supply unit supplying the toner to the conveying member; and a height adjusting member adjusting a uniform height for a toner layer of the toner immediately before a development area on the conveying member in which development is performed.

Abstract: A developing unit for transferring toner onto a latent image on an image carrier so as to develop the latent image includes a toner carrier, an electric field generator and a separating force applicator. The toner carrier including a plurality of electrodes disposed along the surface thereof and insulated from each other transports the toner to a developing area facing the image carrier. The electric field generator applies a periodic voltage to the plurality of electrodes of the toner carrier so that an electric field is generated on the toner carrier surface to cause the toner charged to a given polarity and borne on the surface of the toner carrier to hop. The separating force applicator applies a separating force to separate the toner on the toner carrier from the surface thereof outside the developing area. The separating force applicator is disposed separately from the electric field generator.

Abstract: A marking apparatus including a traveling wave grid toner transport circuit structure for transporting powdered toner along a transport surface, and electric field concentrating elements for selectively enabling toner patches to be projected to an output medium by a projecting electric field.

Abstract: A developer transport body 33 transports a developer T on a transport surface TS in a predetermined direction. This transport surface is composed of a first constituent surface 33f1 which renders relatively large the absolute value of a charge amount of the developer due to friction, and a second constituent surface 33f2 which is disposed downstream of and adjacent to the first constituent surface and which renders the absolute value of the charge amount of the developer smaller than that in an assumed case where the first constituent surface is disposed. The absolute value of the charge amount of the developer transported on the transport surface becomes relatively large on the first constituent surface. Therefore, when the developer is moved toward a latent-image forming surface LS by an electrostatic force, the developer is less likely to be affected by disturbing forces other than the electrostatic force.

Abstract: A marking apparatus including a traveling wave grid toner transport circuit structure for transporting powdered toner along a transport surface, and electromechanical elements for selectively enabling toner patches to be projected to an output medium by a projecting electric field.

Abstract: A toner carrying member includes a plurality of electrodes arranged in a first direction intersecting with a second direction in which its surface moves. A voltage applying unit applies a bias to the electrodes such that an electric field direction is changed temporally in an alternate manner between adjacent electrodes. An adjusting member adjusts an amount of toner carried on the toner carrying member. A toner-cloud facilitating member includes a conductive member arranged between the toner supplying member and the adjusting member in the second direction in opposite to the toner carrying member.

Abstract: There is provided a developer carrying device, including a first carrying body having a first electrode group configured to from a traveling electric field while being applied a voltage sequentially and to circulate charged developer through a facing portion with respect to a developer supply target; and a second carrying body having a second electrode group configured to from a traveling electric field while being applied a voltage sequentially and to circulate the developer through a facing part with respect to the first electrode group so that the developer being carried is supplied to the first carrying body.

Abstract: A Hybrid Scavengeless Development electrophotographic printing system is provided wherein the electrode wires contain carbon nanotube yarn. The use of carbon nanotube yarn alleviates the problem of fundamental strobing image defects, because the electrodes made from the carbon nanotube yarn can be put at a higher tension to density set point, and thereby achieve fundamental resonance frequencies larger than that obtainable from steel. Additionally the yarn's strength is sufficient to withstand the typical forces it is subjected to in a Hybrid Scavengeless Development environment.

Abstract: A toner supply apparatus 6 is configured to be able to supply a charged toner T to a latent image forming surface LS of a photoconductor drum 3. The toner supply apparatus 6 houses a toner electric field transport body 62. The toner electric field transport body 62 has first portions and second portions which differ in toner T transport force. The first portions and the second portions differ in structural feature, such as relative dielectric constant or thickness. By means of such a structural difference, the state of transport of the toner T on the toner transport surface TTS is appropriately set.

Abstract: An improved method and system for non-contact powder image development are provided. The present technique implements a 5-stage jumping development cycle where the initial stage is a momentary over-voltage condition to release the majority of the toner on a donor substrate and the final stage includes the implementation of a decelerating potential to minimize return impact on the donor and therefore toner abuse. It also uses a routine to directly determine improved (e.g. up to optimal) waveform amplitudes and pulse widths based on toner size and q/m, guided by physical insight.

Abstract: An electrophotographic image forming apparatus is disclosed. The electrophotographic image forming apparatus includes a photoconductor body, a donor roller which develops an electrostatic latent image on the surface of the photoconductor body by using charged toners, and a development nip section formed between the photoconductor body and the donor roller by having a predetermined gap between the photoconductor body and the donor roller. A developing traveling-wave electrode for generating a traveling-wave electric field is disposed at a position facing the surface of the donor roller at an upstream side of the moving direction of the photoconductor body relative to the development nip section, and a removing traveling-wave electrode for generating a traveling-wave electric field is disposed at a position facing the surface of the donor roller at a downstream side of the moving direction of the photoconductor body relative to the development nip section.

Abstract: To generate a toner cloud in a development system, a first potential is applied to a donor roll for a first pulse time to project toner from the donor roll toward a photoreceptor; a second potential is applied to the donor roll for a second pulse time to slow the speed at which the toner is projected toward the photoreceptor; a third potential is applied to the donor roll for a third pulse time to hold toner between the donor roll and the photoreceptor; and a fourth potential is applied to the donor roll for a fourth pulse time to urge undeveloped toner to the surface of the donor roll. Voltages may also be applied for selectivity removing toner from a donor roll.

Abstract: Exemplary embodiments provide a direct imaging system and methods for direct marking an image using the system. The disclosed direct imaging system can eliminate the use of at least one of a charge, and/or exposure subsystems in an electrostatographic machine and related processes. Specifically, the direct imaging system can include a direct marking substrate (e.g., a printing substrate) and a development roll member closely spaced from the direct marking substrate. In one embodiment, the development roll member can include a plurality of actuator cells with each actuator cell controllably addressable to eject one or more toner particles adhered thereto. The ejected toner particles can transit the space between the donor roll member and the direct marking substrate, and thereby marking onto the direct marking substrate forming an image.

Abstract: Exemplary embodiments provide a direct imaging system and methods for direct marking an image using the system. The disclosed direct imaging system can eliminate the creation of a latent image and can be used in an electrophotographic machine and related processes. Specifically, the direct imaging system can include a direct marking substrate (e.g., a printing substrate) and a development belt member closely spaced from the direct marking substrate. In one embodiment, the development belt member can include a plurality of actuator cells with each actuator cell controllably addressable to eject one or more toner particles adhered thereto. The ejected toner particles can transit the space between the donor belt member and the direct marking substrate, and directly marking onto the direct marking substrate forming an image.

Abstract: Exemplary embodiments provide a roll member that includes one or more piezoelectric tape and methods for making and using the roll member. The piezoelectric tape can be flexible and include a plurality of piezoelectric elements configured in a manner that the piezoelectric elements can be addressed individually or as groups with various numbers of elements in each group. In an exemplary embodiment, the disclosed roll member can be used as a donor roll for a development system of an electrophotographic printing machine to create controlled and desired toner powder cloud for high quality image development, such as an image on image development in a hybrid scavengeless development (HSD) system.

Abstract: Exemplary embodiments provide a roll member that includes one or more linear arrays of actuator cells and methods for making and using the roll member. In one embodiment, each linear array of the roll member can be controllably actuated as a group by, e.g., an oscillating voltage, to release toner particles adhered thereto and to form a uniform toner cloud in the development area between the roll member and an image receiving member. The controllable actuation can also aid in the unloading process of the residual toner particles from the roll member. In various embodiments, the uniform toner cloud and/or the controllable unloading process can enable a non-interactive development system for image-on-image full-color printing.

Abstract: Exemplary embodiments provide a digital development system and methods for making and using the system. Specifically, the digital development system can utilize a roll member that includes a plurality of actuator cells arranged in a 2-dimensional array with each actuator cell having an actuator membrane individually addressable to eject one or more toner particles adhered thereto. In addition, the digital development system can utilize an imager architecture that includes an addressing logic circuit connected to each cell to selectively control the ejection of the one or more toner particles onto an image receiving member that is closely spaced from each actuator membrane. The disclosed digital development system can be used for non-interactive development systems for image-on-image full-color printing similar to HSD (Hybrid Scavengeless Development) technology with the donor roll becoming a high quality silent imager.

Abstract: Exemplary embodiments provide a roll member that includes one or more controllable cells and methods for making and using the roll member to control an image (or toner) state thereon. The controllable cells can be disposed on a roll substrate and configured in a manner that each controllable cell can be addressed individually and/or as groups. Each controllable cell can be addressable to provide a surface vibration to release toner particles adhered/attracted thereto and can also be capable of sensing the toner state of the roll member and thus to control the image or toner state. In an exemplary embodiment, the disclosed roll member can be used as a donor roll for a development system of an electrophotographic printing machine to create controlled and desired toner powder cloud for high quality image development.

Abstract: A toner supply apparatus 6 is configured to be able to supply a charged toner T to a latent image forming surface LS of a photoconductor drum 3. The toner supply apparatus 6 houses a toner electric field transport body 62. The toner electric field transport body 62 has first portions and second portions which differ in toner T transport force. The first portions and the second portions differ in structural feature, such as relative dielectric constant or thickness. By means of such a structural difference, the state of transport of the toner T on the toner transport surface TTS is appropriately set.

Abstract: A development device capable of suppressing the occurrence of development defects caused by partial damage to an electrode of a toner bearing roller. The development device is provided with a first electrode layer and a second electrode layer, which are laminated so as to overlap one another in a normal direction with respect to the surface of the roller part of the toner bearing roller. A plurality of openings, which are independently arranged in a matrix in both the roller surface movement direction and an orthogonal-to-movement direction which is the direction orthogonal thereto, are provided in, of these electrode layers, the second electrode layer existing in the upper location that is closer to the roller surface, over the entire latent image bearable area of a photosensitive body in the orthogonal-to-movement direction.

Abstract: A developing device constituted to be capable of reliably making toner flare, and carrying out developing normally in the developing area, by preventing toner from adhering to the toner carrier. A developing device having a toner carrier which is disposed in opposition to a latent image carrier and which carries toner for developing an electrostatic latent image on the latent image carrier, the developing device including: a plurality of electrodes aligned at a predetermined interval within the toner carrier; voltage application means for applying a voltage to the electrodes so that the electric field between the plurality of electrodes varies with time, wherein the electric field between the electrodes causes the toner on the toner carrier to hop and form a cloud; and a toner adhesion prevention member that is provided upstream of a developing area where the latent image carrier is in opposition to the toner carrier and that prevents adhesion of toner to the toner carrier.

Abstract: A developing device for a toner powder cloud development system, which can achieve high image quality and can be made compact. The developing device has a two-component development unit, a toner carrier, and an alternating current power source. The toner carrier, which is arranged opposing a latent image carrier, has a plurality of electrodes disposed in a line in a prescribed direction on the surface thereof, and mutually insulated. The alternating current power source supplies a voltage such that an electric field across the plurality of electrodes is temporally switched. The inter-electrode electric field causes the toner being carried on the surface of the toner carrier to carry out hopping, thereby forming a toner powder cloud and carrying out development. The movement speed of the latent image carrier and the linear velocity of the toner carrier are set at approximately equivalent speeds.

Abstract: A hybrid type developing apparatus and method forms a magnetic brush of non-magnetic toner and a magnetic carrier on a circumference of a magnetic roller forms a uniform toner layer on the circumference of a donor roller using only toner from the magnetic roller, and develops an electrostatic latent image on an image receptor. The hybrid type developing apparatus includes: a plurality of electrodes on the circumference of the donor roller; first and second brush electrodes in an upstream area and a downstream area, respectively, of the donor roller facing the magnetic roller with respect to a direction of rotation; and a bias applying device for applying a recovery bias to the first brush electrode to remove toner from the donor roller and a supply bias to the second brush electrode to supply toner from the magnetic roller to the donor roller.

Abstract: A disclosed developing apparatus employs a flare roller that is a toner carrier in which electrodes of two different phases are provided at fine intervals. Density irregularities or scumming in a developed image due to a potential difference between the flare roller and a latent image carrier are prevented by maintaining a constant potential on the flare roller surface. A voltage is applied to the electrodes on the flare roller such that an electric field that varies with time is generated between the electrodes, whereby a toner cloud is produced by the movement or hopping of toner over the flare roller. Thereby the toner attaches to a latent image on the latent image carrier, thus developing the latent image. In one embodiment, a bias with an average potential equal to an average potential of the bias applied to the electrodes is applied to a toner layer thickness regulating member.

Abstract: A development unit includes a toner carrying device, a regulating member, and a toner leak protection member. The toner carrying device having a first electrode and a second electrode arrayed with an interval. The first and second electrodes are supplied with a given voltage to set an electric field, changing in a time cycle, between the first and second electrodes. The electric field is used to hop toner over the toner carrying device to form a toner cloud for developing a latent image. The regulating member regulates an amount of toner on the toner carrying device. The toner leak protection member, made from a conductive material, prevents leakage of toner, and is supplied with a bias voltage.

Abstract: A developing device comprises a latent image carrier that carries a latent image, a toner carrier opposing the latent image carrier while carrying toner to develop the latent image, and plural electrodes arranged in a prescribed direction insulated from each other on the surface of the toner carrier to create an electric field therebetween. An alternating voltage supplying device is provided to supply n number of phases (n?2) of an alternating voltage to the plural electrodes, respectively. The alternating voltage changes the electric field to cause the toner to hop and form toner cloud on the surface of the toner carrier. The toner hopping is halted at a prescribed time period during the toner cloud formation.

Abstract: The development device includes a toner carrier, a toner supplier, and a surface electrical potential controller. When the toner supplier supplies toner particles to the toner carrier, the toner carrier carries toner particles to adhere to a latent image formed on the latent image carrier and has a time constant ?1 of a surface electrical potential change of the toner carrier. The surface electrical potential controller has a time constant ?2 of a surface electrical potential change of the toner carrier smaller than the time constant ?1. The toner carrier includes a plurality of electrodes aligned in parallel and electrically insulated from each other on the surface thereof, and a voltage supplier for supplying each of the plurality of electrodes with a voltage to periodically switch electrical fields therebetween, so that the toner particles form a cloud on the surface of the toner carrier while hopping.