Abstract: A development device includes a toner carrier including first and second groups of electrodes, a toner supplier, and an electrical field generator. 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 connected to a lower potential side of the first DC power source and a cathode connected to an output terminal of the positive-phase pulse voltage generation circuit, and a second diode having an anode connected to the lower potential side of the first DC power source and a cathode connected to an output terminal of the negative-phase pulse voltage generation circuit.

Abstract: A development device includes a developer container, a rotary developer carrier that is disposed facing the latent image carrier and including multiple outer electrodes arranged in a circumferential direction of the developer carrier, an inner electrode electrically insulated from the multiple outer electrodes, an insulation layer disposed between the inner and outer electrodes, and a surface layer overlaying the outer electrodes and electrically insulating the multiple outer electrodes from each other, a bias power source to generate electrical fields that change with time by applying a first and second bias voltages to the inner and outer electrodes, respectively, an electrical field adjuster to regulate the electrical fields in accordance with a thickness of the surface layer of the developer carrier, and a controller.

Abstract: A fixing apparatus includes a fixing member to be heated and a pressure-contacting member for pressure contacting the fixing member. The fixing apparatus directs and conveys a recording member through a nip formed between the fixing member and pressure applying member in such a manner that a toner image carried on a recording member contacts the fixing member in order to be fixed thereto with heat and pressure. The fixing apparatus is configured to direct a tip margin of the recording member toward the pressure applying member across a virtual linear extension line drawn from a downstream end to upstream end of the nip when only the tip margin exits from the nip. A fixing member side separation device may be separately provided from the surface of the fixing apparatus so as to separate the recording member exiting from the nip. A gap formed between the downstream end of the nip and the tip of the fixing member side separation device is set smaller than the width of the tip margin.

Abstract: A disclosed developing device includes a toner carrying member having electrodes, a toner supply unit supplying the toner to the toner carrying member, and a hopping electric field generator unit generating electric field to cause the toner hopping on the toner carrying member by applying a pulse voltage to the electrodes. The hopping electric field generator unit includes a pulse voltage generator circuit generating the pulse voltage, a first direct-current power source supplying bias to the pulse voltage generator circuit for regulating a peak value of the pulse voltage, and a second direct-current power source having a same polarity with a toner charging polarity, and outputting a variable voltage level. The hopping electric field generator unit controls the peak value of the pulse voltage by changing an output of the first power source and a mean thereof by changing an output of the second power source.

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: An developer bearer conveys developer to a developing station under influence of an electric field created by an electric flux line. The developer bearer includes plural kinds of electrodes that receive different voltages from each other and collectively creates the electric flux line. The plural kinds of electrodes are arranged on different layers in a normal line of the developer bearer. The developer bearer includes an insulation layer that insulates the plural kinds of electrodes.

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 unit includes a brush member that includes a base member and a plurality of raisings that are erected on a surface of the base. The brush member traps toner within the raisings and causes a flicker movement in the raisings of the brush so that the toner trapped within the raisings is shaken and flown due to the flicker movement to the surface of a toner carrying member.

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.

Abstract: A development device includes a developer container; a rotary cylindrical developer carrier including an outer electrode including multiple electrode portions arranged in a circumferential direction of the developer carrier, an inner electrode provided on an inner circumferential side of the developer carrier from the outer electrode, an insulation layer disposed between the outer electrode and the inner electrode, and a surface layer; and a bias power source to apply a first bias voltage and a second bias voltage to the inner electrode and the outer electrode, respectively. The first bias power source causes an electrical potential difference that changes with time between the inner electrode and the outer electrode to cause the developer to hop on a circumferential surface of the developer carrier. At least one of the first bias voltage and the second bias voltage has a cyclic waveform in which pulse-on time is reduced.

Abstract: An image forming apparatus includes a latent image carrier to carry a latent image, a developing device having a toner carrier with first and second electrodes to develop the latent image by transferring the toner to a developing region between the toner carrier and the latent image carrier while causing the toner to hop between the first and second electrodes and attaching the hopping toner to the latent image, a pulsed power supply to output a first periodic pulse voltage having a mean potential the same as a normal toner charge and a second periodic pulse voltage, a smoothing circuit to make the first periodic pulse voltage smooth to generate a direct voltage, and a toner layer thickness regulator member to regulate, on receiving the direct voltage, a thickness of the toner layer in a region between a toner supply position at which toner is supplied and the developing region.

Abstract: An image forming apparatus includes a latent image carrier; a latent image writer to write a latent image on the latent image carrier; a developing unit including a toner carrier having first and second electrodes insulated via an insulator member and a voltage applying unit to apply voltages to the first and second electrodes having a potential difference to generate first electric fields to cause the toner to hop from the toner carrier to the latent image carrier to develop a toner image; and a transfer unit to transfer the developed toner image to a transferring member. When alternating voltages having a same phase and same amplitude are applied to the first and second electrodes to form second electric fields between the latent image carrier and the toner carrier, the toner is discharged from the toner carrier to the latent image carrier in a toner discharge mode.

Abstract: An apparatus and method for image fixing are disclosed. A fixing device includes a fixing member, a pressure member, a heater, and a pressure controller. The fixing member and the pressure member face with each other to form a nip. The heater heats a surface of the fixing member when the fixing member rotates. The pressure controller changes a pressure generated at the nip, according to an operation of the fixing device.

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 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 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 development device includes an open-ended housing, a rotatable roller, an array of multiple primary electrodes, a voltage source, a sealing member, and a secondary electrode. The housing accommodates toner for application to the photoconductive surface through an end opening thereof. The roller has an outer circumferential surface to deliver the toner from within the housing to a development zone. The array of multiple primary electrodes are aligned with each other on the roller surface. The voltage source applies a periodic pulse voltage to at least a subset of the primary electrodes to generate an oscillating primary electric field. The sealing member seals clearance between the roller surface and an edge of the end opening downstream from the development zone. The secondary electrode generates a secondary electric field to force the toner from the sealing member toward the roller surface to prevent premature removal of the toner.

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 development device includes a developer container, a rotary developer carrier that is disposed facing the latent image carrier and including multiple outer electrodes arranged in a circumferential direction of the developer carrier, an inner electrode electrically insulated from the multiple outer electrodes, an insulation layer disposed between the inner and outer electrodes, and a surface layer overlaying the outer electrodes and electrically insulating the multiple outer electrodes from each other, a bias power source to generate electrical fields that change with time by applying a first and second bias voltages to the inner and outer electrodes, respectively, an electrical field adjuster to regulate the electrical fields in accordance with a thickness of the surface layer of the developer carrier, and a controller.