Abstract: An image forming apparatus includes a photoconductive medium electrified by an electrifying apparatus to a predetermined electric potential, a plurality of color developing apparatuses which are fixed around the photoconductive medium, each color developing apparatus having a developing roller to adhere a predetermined color toner to an electrostatic latent image formed on the photoconductive medium by a laser scanning unit, and a supplying roller to supply a toner to the developing roller, a voltage supplying apparatus to apply a predetermined bias voltage to the developing roller and the supplying roller, and a controlling apparatus to control a degree and a timing of applying the bias voltages to the developing roller and the supplying roller to control a movement state of the toner between the supplying roller and the developing roller.

Abstract: A development device includes a developer carrier and a developer supply belt. The developer carrier, disposed in contact with an image carrier carrying an electrostatic latent image, carries developer to be charged with a prescribed polarity and develops the electrostatic latent image by application of development voltage. The developer supply belt includes a first roller, a second roller, and a belt. The belt is tightly stretched by the first roller and the second roller, and is disposed in contact with the developer carrier from a contact beginning portion to a contact finishing portion. A potential difference between the development voltage and the voltage of the contact finishing portion is arranged to be zero (0) V or above and 600 V or below.

Abstract: A developing apparatus includes first and second developer bearing members configured to bear developer and a connecting member configured to connect the first and second developer bearing members to each other such that the second developer bearing member is swingable relative to the first developer bearing member. A first adjusting member which adjusts the positions of magnetic poles of a first magnetic member disposed in the first developer bearing member is fixed to the developing apparatus. A second adjusting member which adjusts the positions of magnetic poles of a second magnetic member disposed in the second developer bearing member is fixed to the connecting member.

Abstract: A developer apparatus, includes: a container which houses toner; a toner carrier roller that is provided, on a surface thereof, with a plurality of convex sections which are regularly arranged and a concave section which surrounds the convex sections, is shaped approximately like a cylinder, and rotates while carrying a toner layer of charged toner on the surface thereof; and a restriction member that abuts on the surface of the toner carrier roller to form a restriction nip, restricts a thickness of the toner layer carried on the surface of the toner carrier roller in the restriction nip, and removes the toner layer on the convex sections from among the toner layer carried on the surface of the toner carrier roller at an upstream-side end of the restriction nip in a rotation direction of the toner carrier roller, wherein a part of toner carried by the concave section moves to the convex sections to cover the convex sections with the toner at a downstream side to the restriction nip in the rotation direction

Abstract: Provided are an image forming apparatus equipped with a hybrid developing apparatus including a toner-collecting developer-carrying member and a method for developing an electrostatic latent image, which apparatus is capable of stably forming high definition images without occurrence of a leakage current even under a high-humidity environment. In the apparatus, each of a toner-supplying developer-carrying member and the toner-collecting developer-carrying member has a conductive substrate to which a bias voltage is applied, and at least one of the surfaces of the conductive substrates of the toner-supplying developer-carrying member and the toner-collecting developer-carrying member has a resistive layer formed thereon.

Abstract: An image forming apparatus changes over an electric potential on an image bearing member in response to an attenuation region in which a remaining potential on a developing member is attenuating after a developing bias applied to the developing member has been turned off after completion of an image forming operations. Accordingly, it is possible to mitigate adherence of developer due to a large potential difference between the developing member and the image bearing member.

Abstract: The present invention teaches and claims an image forming apparatus comprising an image forming portion using a liquid developer having a carrier liquid and toner; an intermediate transfer section which has an endless belt and a plurality of rotating bodies; a second transfer roller which is disposed so that it faces one of the plurality of rotating bodies and abuts the endless belt; a first bias applying section which is connected to the second-transfer roller and applies a transfer bias to the second-transfer roller when the second-transfer is done and applies a reverse transfer bias having a same electric polarity as the transfer bias to the second-transfer roller when the second-transfer is not performed; and a second bias applying section which is connected to the rotating body facing the second-transfer roller and applies a bias to the rotating body facing the second-transfer roller.

Abstract: A developing device for developing an electrostatic latent image on an image carrier by supplying a one-component developer to the image carrier. Good images can be obtained over long periods of time, without printing history becoming apparent on account of residual developer. The developing device has a developer carrier that is rotatable and disposed facing an image carrier; and a conductive developer supply and recovery member rotatably arranged so as to abut the developer carrier. The rotation direction of the conductive developer supply and recovery member is opposite to the rotation direction of the developer carrier at a position where the developer carrier and the conductive developer supply and recovery member abut each other. A contact pressure P between the developer carrier and the conductive developer supply and recovery member is set so as to satisfy the relationship 0 (kPa)<P<5.0 (kPa).

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: An image forming apparatus uses a two-component developer containing a toner and a carrier. The apparatus has a latent image bearer for bearing an electrostatic latent image. A toner bearer bears the toner to be conveyed to a development region to develop the electrostatic latent image. A developer bearer bears the two-component developer and supplies the toner to the toner bearer. A regulator sets the thickness of a toner layer carried on the toner bearer to 6 ?m to 15 ?m and sets a difference between a half width of a first toner charge number distribution as a number distribution of the charge amount of the toner carried on the toner bearer and that of a second toner charge number distribution as a number distribution of the charge amount of the toner in the two-component developer carried on the developer bearer to 0.8 (10?10 C/m) or smaller.

Abstract: An image forming apparatus including: an image bearing member having a photoconductive layer of a capacitance per unit area of 1.7×10?6 (F/m2) or more; and a developing device having a developer carrying member to which development voltage is applied for developing a latent image to form a toner image on the image bearing member, wherein the following expression is satisfied: ? Q M ? ? 0.

Abstract: An electrostatographic apparatus and method of forming a toner image on a receiver using a segmented roller in order to improve transfer of a pigmented toner image to a receiver. The pigmented toner image is applied using the segmented roller and is then transferred to a receiver sheet.

Abstract: The invention provides, as an aspect thereof, an image formation apparatus that includes: an image carrier that carries a latent image; a toner carrier that has, on a surface of the toner carrier, a concave portion arrayed in a regular pattern so as to carry toner, and develops the latent image that is carried on the image carrier by means of the toner carried in the concave portion; and a voltage application section that applies a development voltage to the toner carrier for the purpose of the development of the latent image. In the configuration of an image formation apparatus according to the above-described aspect of the invention, immediately after that the toner carrier has developed the latent image, which is carried on the image carrier, by means of the toner carried in the concave portion in response to the application of the development bias to the toner carrier by the voltage application section, at least one layer of the toner remains carried in the concave portion.

Abstract: An image forming apparatus has a developer container containing a developer and a developer carrying member for carrying the developer and adapted to switch an AC voltage to be applied to the developer carrying member. The apparatus includes a detecting member for detecting the amount of developer in the developer container and a processing portion for determining the amount of developer in the developer container according to the value output by the detecting member when the AC voltage is applied to the developer carrying member. The processing portion is adapted to determine the amount of developer by executing a process that corresponds to the operation of switching the AC voltage.

Abstract: An image forming apparatus is characterized in that an absolute value of a difference between a first coefficient of variation in a number distribution of the particle diameter of a toner carried on a developing roller and a second coefficient of variation in a number distribution of the particle diameter of a toner in a two-component developer carried on the magnetic roller is within 5% and an absolute value of a difference between a third coefficient of variation in a number distribution of the particle diameter of a toner of a toner image developed on the outer surface of an image bearing member and the second coefficient of variation is within 6%. With such an image forming apparatus, high-quality images can be stably formed over a long term.

Abstract: An image forming apparatus has a photoconductive member, and a developing roller develops a latent image on the photoconductive member by a first alternating-current bias in the form of a rectangular wave. The following relationships are satisfied in calculating the duty ratio (D1) of the first alternating-current bias using an application period of voltage in a direction to transfer the toner from the developing roller towards the photoconductive member as a positive period: a CV value in the number particle size distribution of the toner is ?25%, 4 ?m?Dt?7 ?m, 105 ?·cm?pv?109 Q?cm, 0.4 ?m?Ra?1.5 ?m, and 35%?D1?75%. where Dt denotes the volume average particle diameter of the toner, pv denotes the intrinsic resistance value of a developing roller surface, Ra denotes the arithmetic average roughness of the developing roller surface.

Abstract: In an image forming apparatus 1 including a photoconductive drum 31 on which an electrostatic latent image is formed and a developer carrier that is allowed to carry a developer thereon by a developing bias voltage applied thereto composed of a DC component and an AC component and that is arranged in the vicinity of the photoconductive drum 31, the image forming apparatus 1 visualizing the electrostatic latent image using the developer carried on the developer carrier, a high-frequency region A with respect to which image forming is performed with the frequency of the AC component of the developing bias voltage increased and a low-frequency region B with respect to which image forming is performed with the frequency of the AC component of the developing bias voltage decreased are formed in an image to be formed on recording paper.

Abstract: An image forming apparatus including a photosensitive member on which an electrostatic latent image is formed, an image forming unit to form a visible image on the photosensitive member formed with the electrostatic latent image, and a transfer device to transfer the visible image formed on the photosensitive member onto a printing medium. The image forming unit includes a developing agent storage vessel to store a developing agent therein, a developing unit having a conductive layer to which the developing agent is attached and used to attach the developing agent to the photosensitive member, and a supply unit to supply the developing agent stored in the developing agent storage vessel to the developing unit. The developing unit and the supply unit satisfy a relational expression 1.7?logSr/logDr?2.5, where Sr a volume resistance of the supply unit and Dr is a volume resistance of the developing unit.

Abstract: An image forming apparatus provided with an image carrying member to carry an electrostatic latent image, a toner carrying member to develop the electrostatic latent image on the image carrying member with toner; a first developer carrying member to carry developer containing toner, carrier, reverse polarity particles and to supply toner to the toner carrying member; and a second developer carrying member to carry developer and to recover toner on the toner carrying member, wherein an ability to move the reverse polarity particles from the toner carrying member to the first developer carrying member is larger than an ability to move the reverse polarity particles from the second developer carrying member to the toner carrying member.

Abstract: An image forming apparatus includes: a plurality of development units having developing-agent carriers which are provided in correspondence to three or more developing agents, and developing electrostatic latent images on surfaces of image carriers to form developing-agent images on the image carriers; and a recovery unit that recovers the developing agent adhering to the developing-agent carrier during non-development operation. The recovery unit is provided for at least the development unit other than the development unit that transfers the developing-agent image first in sequence among the plurality of development units. When one of the plurality of development units performs development by the developing agent whose charge capability is higher than that of the developing agent of the development unit that transfers the developing-agent image later in sequence, the recovery unit starts recovery of the developing agent or performs recovery operation for improving recovery capability of the developing agent.

Abstract: A developing unit for transferring toner onto a latent image on an image carrier to develop the latent image including a toner carrier, an electric field generator and a separating force applicator. The toner carrier includes a plurality of electrodes disposed along the surface thereof and insulated from each other. The electric field generator applies a periodic voltage to the plurality of electrodes of the toner carrier to generate an electric field i 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.

Abstract: The present invention provides a developing apparatus using a two-component developer, an image forming apparatus, and a method of forming an image capable of forming a high quality image characterized by stable suppression of carrier deterioration and absence of a residual image (memory effect) for a long period of time. The voltage formed by overlapping AD voltage to DC voltage is applied separately to each of the developer carrying member and the toner carrying member. The toner separation field made up of AC field is formed between the developer carrying member and the toner carrying member, and the development electric field made up AC field is formed between the toner carrying member and the image carrying member.

Abstract: An image forming apparatus changes over an electric potential on an image bearing member in response to an attenuation region in which a remaining potential on an image bearing member attenuates after a developing bias applied to the developing member has been turned off after completion of an image forming operation. Accordingly, it is possible to mitigate adherence of developer due to a large potential difference between the developing member and the image bearing member.

Abstract: The invention realizes a uniform toner coating on a developing roller, thereby preventing a density unevenness and a toner dripping and suppressing a developing roller set mark image in a contact developing method, by conditions that the DC voltage applied to the developer regulating member is the same as the DC voltage applied to the developer carrying member or at a side of a charging polarity of the developer with respect to the DC voltage applied to the developer carrying member; and a frequency f (Hz) and a peak electric field strength E (V/m) of the AC electric field formed by the AC voltage between the developer regulating member and the developer carrying member, and a peripheral speed v (m/s) of the image bearing member satisfy conditions: 4.2×v?f?2500 and 2.2×106?E?5.2×106.

Abstract: A developing device that can suppress occurrence of fogging is achieved. The developing device is provided with: a developer bearing member for bearing a developer; and a charging member for charging the developer borne by the developer bearing member. The charging member has: a first layer that is placed in contact with the developer bearing member and that contains a conductive agent; and a second layer that is positioned on a side opposite from the developer bearing member with respect to the first layer, and that contains a conductive agent at a density that is greater than the density of the conductive agent contained in the first layer.

Abstract: An image forming apparatus includes an image bearing body and a developer bearing body. A transferring section transfers, onto a medium, a developer image formed on the image bearing body by development of the latent image. A voltage applying section alternately applies, to the developer bearing body, a first voltage for making the developer move from the developer bearing body toward the image bearing body in order to develop the latent image, and a second voltage for making the developer move from the image bearing body toward the developer bearing body. An image darkness adjusting section adjusts a darkness of the image to be formed on the medium by changing only the second voltage.

Abstract: The present invention provides a one-component development type developing apparatus including a rotatable electrostatic latent image holding member 1 on the surface of which an electrostatic latent image is formed, and using a toner 4 for rendering the electrostatic latent image visible, wherein when the shape factor SF-1 of a toner fine particle is expressed by: SF-1=(M2/A)×(?/4)×100 where A is the projected area of the fine particle and M is the absolute maximum length of the fine particle, then the shape factor SF-1 of the toner 4 is at least 100 and at most 140, and the developing apparatus includes: a toner holding member 3 that is formed from a silicone rubber elastic material and that is for holding the toner 4 and transporting it to the electrostatic latent image holding member 1; a toner layer regulating member 9 for forming the toner on the toner holding member 3 into a thin layer; and a toner supply member 5 that is formed from a silicone rubber foam and that rotates, in a position opposed to th

Abstract: A high developing voltage supply apparatus includes solenoid power switches, and a high developing voltage driver selectively outputting a solenoid driving signal to close one of the solenoid power switches to electrically close a corresponding mechanical contact, applying a high developing voltage to one of color development rollers corresponding to the mechanical contact closed and Kased on an image to be printed. A high developing voltage supply supplies the high developing voltage to developing roll shafts of the other color development rollers to stabilize potentials of the developing roll shafts, or, in the alternative, the high developing voltage supply apparatus may include a voltage supply supplying a self-biased voltage to the other color development rollers using the high developing voltage formed with a DC voltage VDC and an AC voltage VAC superimposed.

Abstract: A heater includes: a hollow tube sealed hermetically and reduced in pressure, the interior of the hollow tube being divided by at least one partition wall into a plurality of regions arranged side by side in a longitudinal direction of the tube; an electron source provided in each of the divided regions, the electron source being supported inside the hollow tube in an electrically insulated state from the hollow tube; a power supply that applies a voltage between the hollow tube and the electron source with the electron source as a negative polarity side; and the electron source emitting electrons toward an inner periphery surface of the hollow tube to heat the hollow tube.

Abstract: An image forming method includes measuring an electrical potential on a surface of a developer roller and adjusting a time varying component of a voltage applied to the developer roller using a measurement of the electrical potential.

Abstract: A developing apparatus including a developer carrying member for carrying a developer for developing an electrostatic image, formed on an image bearing member, with the developer, a developer regulating member for regulating the developer carried on the developer carrying member, and an oscillating electric field forming device which forms an oscillating electric field between the developer carrying member and the developer regulating member, wherein a developer consuming operation is executed for consuming the developer from the developer carrying member to an image non-forming area of the image bearing member and a period of forming the oscillating electric field is provided in the operation.

Abstract: A base sheet is spanned over a lower roller, and an upper roller pulls a cover sheet along a path and presses it against the base sheet at the lower roller. A preheater housing along the path upstream of the rollers is formed with a chamber open toward the path. A radiant heater in the chamber is directed transversely at the path so as to heat the cover sheet passing along the path. A sensor along the path adjacent the chamber detects atmosphere around the chamber and generates an output when the detected atmosphere indicates an unsafe hot condition of the cover sheet. A shutter can shift between a retracted position offset from the chamber and an advanced position closing the chamber. A controller connected to the sensor shifts the shutter from the retracted position to the advanced position when the output is generated by the sensor.

Abstract: A developing apparatus including a developer carrying member, a developer layer regulating member and a flight developer regulating member, wherein the developer carrying member is provided in opposed relationship with an image bearing member and carries a developer thereon, and in an opposed portion between the image bearing member and the developer carrying member, an oscillating electric field is formed between the image bearing member and the developer carrying member, and the developer is caused to fly from the developer carrying member to the image bearing member, and the developer layer regulating member regulates a layer of developer on the developer carrying member, and the flight developer regulating member is mounted on the developer layer regulating member, and regulates an area in which the developer flies in the opposed portion.

Abstract: A developing device includes a removing roller positioned vertically above a supplying roller and in contact with a developing roller. Positively charged toner is supplied from the supplying roller to the developing roller and then supplied to a photosensitive drum for developing an electrostatic latent image thereon. Toner remaining on the developing roller that was not supplied to develop the latent image is removed by the removing roller. Some of the toner stripped by the removing roller falls down toward the supply roller and is again supplied to the developing roller.

Abstract: A developer supplying device including a developer holding unit configured to hold a developer, a developer transfer device configured to electrostatically transfer the developer from the developer holding unit, and a charging member having holes piercing therethrough from the developer holding unit, to abrasively charge the developer by contacting the developer with walls of the holes while the developer is electrostatically transferred through the holes by the developer transfer device.

Abstract: It is intended to provide a developing apparatus, an image forming apparatus and developing method capable of managing both decrease of load on apparatuses and improvement of image quality in case development of an image is made by applying contact developing and AC developing. For that intention, voltage at a portion between a development member and an image carrier is defined oscillating voltage, and in case negative polarity toner is used, relations of peak voltage V1 of oscillating voltage, background portion voltage VH (negative) and visible section voltage VL (negative, an absolute value of it is smaller than that of VH) are set as indicated below. ?500V?V1?VL??350V ?200V?V1?VH??50V On the above conditions, peak voltage V2 is set as indicated below. ?150V?VL?V2??70V V2?VH+500V.

Abstract: A developing unit is adapted to an image forming apparatus of an electrophotographic system that has a two component developing agent. The developing unit deposits a thin layer of toner on a developing roller by way of a magnetic brush on a magnetic roller. The toner then is transferred from the developing roller to a photosensitive drum. Developing bias voltages applied to the rollers have DC and AC components. Thus, electric current alternately flows in the magnetic roller and the developing roller to accelerate toner transfer. Sufficient toner is supplied from the magnetic roller to the developing roller, and sufficient toner is recovered from the developing roller to the magnetic roller. This arrangement lowers the amplitude of the AC bias voltage, thereby eliminating an influence on the photosensitive drum. Further, the frequencies of the AC bias voltages are constant. Thus AC bias voltage generating circuits have a low cost.

Abstract: An image forming device includes a developer bearing member, a photosensitive member, a developing-bias applying portion, a pressing-force adjusting portion, and a density adjusting portion. The photosensitive member is disposed in contact with the developer bearing member. An electrostatic latent image is formed on the photosensitive member and developed by the developer supplied from the developer bearing member for forming a developer image. The developing-bias applying portion applies a developing bias to the developer bearing member. The pressing-force adjusting portion adjusts the pressing force between the developer bearing member and the photosensitive member.

Abstract: An image forming apparatus operates in such a way that when the conditions of toner changes due to changes in environmental conditions, changes with age, and replacement of an EP cartridge, the bias voltages for a charging roller, a developing roller, and a toner-supplying roller are set appropriately. An electrostatic latent image can be formed on a photoconductive body. The developing roller causes developer to adhere to the electrostatic latent image to develop the electrostatic latent image. The toner-supplying roller supplies the developer to the developing roller. The current measuring section measures a current flowing through at least one of the developing roller and the toner-supplying roller. An voltage-setting section sets at least one of the developing roller and the toner-supplying roller to a corresponding one of first voltages, the first voltages being set in timed relation with development of the electrostatic latent image.

Abstract: A developing device has a voltage application member which is in contact via a toner layer with a developing roller that rotates while holding the toner layer on its outer peripheral surface. A voltage that the voltage application member applies to the toner layer is switched between AC voltage and DC voltage based on humidity or drive cumulated time of the developing device.

Abstract: The image forming apparatus has a photosensitive drum, a charging device for charging the surface of the photosensitive drum, an exposing head for exposing the charged surface to an exposure light in order to form an electrostatic latent image, and a developing device for developing the electrostatic latent image by causing toner adhere to the electrostatic latent image. The developing device includes a developing roller for carrying toner to be supplied to the photosensitive drum, a toner supplying roller for supplying toner to the developing roller, and a blade for shaping toner on the developing roller into a thin toner layer. The developing roller, the toner supplying roller, and the blade are applied with voltages VD, VS, and VB respectively, the voltages VD, VS, and VB being determined depending on surrounding temperature and humidity, and satisfying the relationship of |VB?VD|<|VS?VD|.

Abstract: An electro-photographic image forming apparatus preventing toner from scattering during a printing operation and a control method of the same. The electro-photographic image forming apparatus includes a scattering preventive member being disposed downstream of the developing roller at a predetermined distance from the photosensitive medium, and a voltage being applied, and a controller controlling the voltage that is applied to the scattering preventive member so as to transport the toner attached on the scattering preventive member to the photosensitive medium.

Abstract: The electrophotographic image formation apparatus of the present invention adopts a developer roller, which is made of aluminum and has an aluminum oxide film of at least 5 ?m in thickness formed on surface thereof. In the image formation apparatus, a gap between the developer roller and a photoreceptor drum 3 is set in a range of 150 to 300 ?m. The image formation method of the present invention regulates a frequency of AC voltage in a non-development state to be higher than that in a development state, when an AC voltage is applied onto the developer roller to cause flight of toner from the developer roller to the photoreceptor, and selectively makes charged toner fly onto the electrostatic latent image for development. The present invention provides the effective development technique to prevent leakage of the applied voltage between the developer roller and the photoreceptor drum.

Abstract: The invention provides a developing apparatus, an image forming apparatus and a toner replenishing method that can restrain deterioration of toner and can stably form high quality image. Replenishing bias voltage is applied to a developing roller and a replenishing roller to charge conductive toner kept on a surface of the replenishing roller to a predetermined amount of charge. By electric field generated between the developing roller and the replenishing roller on the basis of the applied replenishing bias voltage, charged conductive toner is made fly and replenished from the replenishing roller to the developing roller. An appropriate amount of conductive toner is kept in a toner transporting body formed on a surface of the developing roller and is supplied to a photoconductor roller.

Abstract: An electrostatic latent image is formed on an image carrier. A first roller is opposed to the image carrier with a gap in between. A second roller is in contact with the first roller such that toner of a one-component type is supplied onto the image carrier by way of the first roller to develop the electrostatic latent image as a visible toner image. A single power source supplies a bias voltage in which an AC voltage is superposed on a DC bias voltage. The bias voltage is supplied to the first roller through a first path and to the second roller through a second path. A resistor is provided on the first path between the first roller and a branching point of the first path and the second path.

Abstract: A developing device including a latent image supporter. Powder is adhered on the latent image supporter to develop a latent image on the latent image supporter and a transporting member is arranged opposite to the latent image supporter. A plurality of electrodes are formed in the transporting member for generating a traveling-wave electric field to move the powder, and n-phase voltages are applied to the electrodes of the transporting member to form an electric field in a first direction so that the powder moves towards the latent image supporter at an image portion of the latent image and in a second direction so that the powder moves in a direction opposite to the latent image supporter at a non-image portion of the latent image.

Abstract: An apparatus for developing a latent image recorded on a movable imaging surface, including: a reservoir for storing a supply of developer material including toner particles, said reservoir including a transport member; a donor member being arranged to receive toner particles from said transport member and to deliver toner particles to the image surface at locations spaced apart from each other in the direction of movement of the imaging surface thereby to develop the latent image thereon; a power supply, connected to said donor member, for biasing said donor member to deliver toner to the image surface during a printing mode of operation; a second power supply, connected to the transport member, for maintaining a predefined voltage difference between the transport member and the donor member such that toner particles are attracted to the donor member from the transport member during a printing mode of operation; a controller for generating a donor member purge signal trigger based on sensed or calculated dev

Abstract: An image forming apparatus includes a plurality of developing devices, each of which includes a developer carrying member for carrying a developer to develop an electrostatic image formed on an image bearing member with a developer, and a developer regulating member for regulating the developer carried on the developer carrying member; a common voltage applying device for applying voltages to the developer regulating members, wherein the voltages are applied to the developer carrying members are variable independently from each other, and when at least one of the voltages varies, the voltage applied by the voltage applying device is capable of being changed.

Abstract: A method of forming an image includes the steps of providing a development bias having a DC component and an AC component superposed on one another and applying the development bias to a developer carrying member. The AC component is provided by superposing a waveform at a second frequency on a waveform at a first frequency in synchronism with each other. The second frequency is an odd multiple of the first frequency.

Abstract: A developing device used with an electrophotographic image forming apparatus and developing method thereof includes a power supplying unit which applies a first electric field to a toner transfer body and a supplying member so that the toner is supplied to the toner transfer body when a development operation is performed, and applies a second electric field to the toner transfer body and the supplying member so that the toner is removed from the toner transfer body when the development operation is not performed, by varying a developing bias and a supplying bias.