Abstract: Provided are a developing device and an image forming apparatus, the developing device which employs a two-component developer wherein development hysteresis (ghost) is reduced and deterioration of a carrier is stably suppressed, and high-quality images are thus realized for a long period of time. The developing device, which uses a developer including toner, carrier and reverse polarity particles which are charged to have a polarity reverse to that of the toner, performs a collecting operation for collecting the reverse polarity particles at a timing in which image formation is not affected by a collecting operation, where the reverse polarity particles are accumulated in the area enclosed by a toner carrying member, a developer carrying member for toner supply and developer carrying member for collecting toner are collected into a developer container.

Abstract: A developing device capable of improving the image density and the dot reproducibility, and an image forming apparatus including the same are provided. A developing device applies an alternating voltage superimposed on a direct current voltage to a developing roller to thereby develop an electrostatic latent image formed on a photoreceptor with toner. A bias voltage waveform superimposed at this time has an original period (first period) in which each of a development-side electrical potential and an opposite development-side electrical potential is applied one time and a period (second period) in which a Vpp is gradually increased from the initial value to the maximum value.

Abstract: A developing device including a developer bearing member configured to feed a developer to an image bearing member; a developer supplying member, which is contacted with the developer bearing member at a first nip while opposed thereto and which is configured to supply the developer to the developer bearing member; and a developer layer forming member, which is contacted with the developer bearing member at a second nip located on the downstream side from the first nip relative to the rotation direction of the developer bearing member to form the layer of the developer on the developer bearing member, wherein the developer is a nonmagnetic one component developer, and the distance between the front edge of the second nip and the rear edge of the first nip relative to the rotation direction of the image bearing member is greater than 0.8 mm and less than 2.0 mm.

Abstract: An image forming apparatus includes an image bearing member; a developer carrying member, contactable to the image bearing member, for carrying a developer to a developing position to develop an electrostatic image formed on the image bearing member with the developer; a supplying member for supplying the developer to the developer carrying member, wherein a peripheral speed of the developer carrying member is not less than 1.05 times and not more than 1.20 times a peripheral speed of the image bearing member, and an arithmetic average roughness Ra is not less than 0.20 times and not more than 0.33 times a volume average particle size of the developer, wherein a potential applied to the supplying member is different from a potential applied to the developer carrying member toward a larger potential of a regular charge polarity of the developer.

Abstract: An image forming apparatus include an image bearing member, a developing container receiving a developer, a developer carrying member for carrying and conveying the developer, a developer feed member for supplying the developer to the developer carrying member, a detection device for detecting an amount of developer in the developing container by detecting an electrostatic capacitance between the developer carrying member and the developer feed member, and a control device for changing a rotational speed of the developer feed member into a plurality of speeds corresponding to the plurality of image forming speeds. The control unit controls the rotational speed of the developer feed member prior to the execution of a detection operation of the detection device so as to be faster than the slowest speed of said plurality of speeds.

Abstract: In an embodiment in which an electrostatic latent image formed on the surface of a photoreceptor is developed with a toner by applying an oscillating bias voltage in which a development-side electrical potential and an opposite development-side electrical potential alternate with each other, between a development sleeve of a development roller and the photoreceptor, the development-side electrical potential is applied in two stages, and, in the two-staged development-side electrical potential, the absolute value of a first electrical potential V1 that is initially applied is larger than the absolute value of a second electrical potential V2 that is subsequently applied.

Abstract: An aspect of the invention provides a developing unit that includes: a developer; an image carrier on which an electrostatic latent image is formed; a first developer carrier configured to develop the electrostatic latent image formed on the image carrier by causing the developer to adhere to the electrostatic latent image; a first restriction member configured to be in press-contact with the first developer carrier; a second developer carrier configured to abut to the first developer carrier, and to form a developer layer on the second developer carrier; a second restriction member configured to abut to the second developer carrier; and a supplying member configured to supply the second developer carrier with the developer.

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: An image forming apparatus having a touchdown-development type developing apparatus, in which a toner collecting roller that collects scattered toner suspended in the vicinity of a toner holding body and a two-component developer holding body is arranged on the downstream side in a rotational direction of the two-component developer holding body from a closest position of the two-component developer holding body and the toner holding body, and between the two-component developer holding body and the housing wall, and further, bias means that applies a bias voltage for collecting the scattered toner to the toner collecting roller, and image density sensing means for sensing a density of a toner image developed on the electrostatic latent image holding body surface or a toner image on a transfer body onto which the toner image developed on the electrostatic latent image holding body surface is transferred to control the bias voltage are provided.

Abstract: There is provided an image formation device, comprising: a holding body configured to hold thereon developer and to have a center axis extending in a main scanning direction; and a developer supply unit configured to supply the developer to the holding body through a traveling electric field, the developer supply unit having an opening through which a part of the holding body is accommodated in the developer supply unit. In this configuration, the developer supply unit comprises a sliding member configured to slide on at least a part of a surface of the holding body moving toward an outside of the developer supply unit through the opening.

Abstract: An image forming apparatus include an image bearing member, a developing container receiving a developer, a developer carrying member for carrying and conveying the developer, a developer feed member for supplying the developer to the developer carrying member, a detection device for detecting an amount of developer in the developing container by detecting an electrostatic capacitance between the developer carrying member and the developer feed member, and a control device for changing a rotational speed of the developer feed member into a plurality of speeds corresponding to the plurality of image forming speeds. The control unit controls the rotational speed of the developer feed member prior to the execution of a detection operation of the detection device so as to be faster than the slowest speed of said plurality of speeds.

Abstract: An image forming apparatus, wherein the following formulae are satisfied: 0.22 ? ( M / S ) L ? 0.4 , ? ( Q M ) L = Vc ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.1 } ? ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L 500 ? ?? ? ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.1 } ? ( Lt 2 ? ? 0 ? ? t + Ld ? 0 ? ? d ) × ( M S ) L 150 ?? ? ( Dt ? ? max - Dt 0.1 ) { ? × ( M S ) L - 0.

Abstract: An image forming apparatus including a first developing device including a first developer carrying member for carrying a developer containing toner, wherein a developing voltage including an AC component is applicable to the first developer carrying member to develop an electrostatic image; a second developing device including a second developer carrying member for carrying a developer containing toner, wherein a developing voltage including an AC component is applicable to the second developer carrying member to develop an electrostatic image; a transferring device for transferring a toner image formed by the first developing device to a moving transfer medium and then transferring a toner image formed by the second developing device onto the transfer medium; a controller for selectively executing an operation in a first mode wherein the image is formed by both of the first developing device and the second developing device or in a second mode wherein the image is formed by only the second developing device

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 development apparatus is provided that can quickly form high quality printing material by steadily supplying developer charged and thinned to a uniform thickness and can also prevent the decrease in the quality of the printing material in a case where the developer carrier and developer supply unit are operated quickly. The toner supply roller is constructed in a manner using the elastic material with a hardness of HAF [degree] set to 20?HAF?80 measured by an Asker F-type and disposed in a manner such that the amount of push ?, defined as the amount pushed by the contact between the developer supply unit and the developer carrier, is 0.5 [mm] or below. In addition, toner supply bias voltage VS [V] applied to the toner supply roller has a frequency f [Hz] of 500?f?5000, and, with VSH and VSL as the peak values of the AC voltage component, fulfill the condition of 1?|VSH?VD|/|VD?VSL?5.

Abstract: An image forming apparatus includes a developer carrying member to which a developing bias is applied. A frequency f of a developing bias waveform, a developing area S1 which is a time-integrated value of a difference between a voltage value of the developing bias and a solid electrostatic image potential VL in a developing period of the developing bias, a collecting area S2 which is a time-integrated value of a difference between the voltage value of the developing bias and VL in a collecting period of the developing bias, and a developing contrast value Vcon are used for defining a range of a value of the developing bias frequency f, a range of a value of a voltage change rate ? at VL during transition of the developing bias voltage value from a developing-side voltage to a collecting-side voltage, and a range of a value represented by the formula: {(S1?1.28×S2)×f/Vcon}×exp(?2.0×10?5×f/Hz).

Abstract: An image forming device is provided which includes a developer carrying body and a developer supply device to supply a developer to the developer carrying body. The developer supply device includes a plurality of transfer electrodes, and a transfer voltage applying unit to apply traveling-wave shaped transfer voltages to the plurality of electrodes. The developer includes a fine particle charged in a predetermined polarity and a fine particle charged in an opposite polarity which is opposite to the predetermined polarity. The transfer voltage applying unit is configured to apply the transfer voltages having waveforms, which make a fly height of the fine particle charged in the predetermined polarity higher than a fly height of the fine particle charged in the opposite polarity, to the plurality of transfer electrodes.

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?log Sr/log Dr?2.5, where Sr a volume resistance of the supply unit and Dr is a volume resistance of the developing unit.

Abstract: A developing device facing an image carrier and including a developer carrier, a developer flying control member, and a development-noise control member. The developing device develops an electrostatic image formed on the image carrier by causing the developer to fly from the developer carrier to the image carrier upon an application of an alternating-current bias to the developer carrier. Noise produced by the development-noise control member vibrated by an oscillating electric field of the alternating-current bias is smaller than a noise produced by the developer flying control member vibrated by the oscillating electric field.

Abstract: A developer supply device, comprising: a casing; first electrodes located at a first most downstream position defining a certain distance with respect to the supply target and positions between the casing and the first most downstream position to form a first traveling electric field; a second electrodes that are located at a second most downstream position defining the certain distance with respect to the supply target and positions between the casing and the second most downstream position to form a second traveling electric field; a power circuit that supplies a first voltage and a second voltage having a same frequency respectively to the first electrodes and the second electrodes such that a phase of voltage change of a first most downstream electrode and a phase of voltage change of a second most downstream electrode shift with respect to each other.

Abstract: A developing apparatus includes: a housing which contains toner; a toner supporting roller; and a regulating blade, wherein bias voltage is applied to the regulating blade, the toner includes, an insulating external additive and an electrically-conductive external additive, satisfies any of the following first to third conditions, the first condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive, the second condition: a volume average grain diameter of the electrically-conductive external additive is larger than a volume average grain diameter of the insulating external additive in which coverage in the toner is higher than that of the electrically-conductive external additive, and the third condition: coverage of the electrically-conductive external additive in the toner is higher than coverage of the insulating external additive that is larger in volume average grain diameter than the elect

Abstract: An image forming apparatus includes a photoreceptor having a first support shaft supported in a first frame body, a photosensitive portion supported by the first support shaft, and a tapered portion having first tapered surfaces on both sides of the photosensitive portion; a development roller opposed to the photoreceptor and having a second support shaft rotatably supported by a second frame body, the development roller being movable in a direction perpendicular to the second support shaft so as to approach and separate from the photoreceptor; roller members disposed on both sides of the development roller coaxially with the second support shaft, the roller member being movable in an axial direction of the second support shaft and including a second tapered surface which abuts against the first tapered surface; a moving member allowing the roller member to move on the second support shaft; and a biasing member biasing the development roller toward the photoreceptor.

Abstract: The purpose is to provide, in a development apparatus using a two-component developer, a compact development apparatus, image forming apparatus and development method that prevents carrier deterioration and that can carry out good image formation over a long time period. In a development apparatus using a developer in which are mixed a toner, a carrier, and opposite polarity particles that are charged to a polarity opposite to the charging polarity of the toner, the surface charge density of the opposite polarity particles should be in the range of 0.5 to 3.0 times the surface charge density of the carrier.

Abstract: Various embodiments and methods relating to a pixel are disclosed.

Abstract: An image forming apparatus includes a developer bearing member for transporting developer to an opposing position opposing an image bearing member. Regularly-disposed concave sections are formed on a surface of the developer bearing member. An alternating voltage that includes a first voltage for moving developer from the developer bearing member toward the image bearing member, and a second voltage for moving developer from the image bearing member toward the developer bearing member is applied to the developer bearing member. A cycle period of the alternating voltage is larger than a minimum width of the concave section in a circumferential direction of the developer bearing member divided by a moving velocity of a surface of the rotating developer bearing member.

Abstract: Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit that has a toner carrier; a transferring unit that transfers the toner image on the transfer medium; and a cleaning unit that removes a toner that remains to be adhered to the latent image carrier, wherein the toner carrier carries a toner layer including a contact toner that is directly in contact with the surface of the toner carrier and a non-contact toner that is not directly in contact with the surface of the toner carrier on the surface thereof, and wherein a voltage of the transferring bias is a DC voltage that does not generate discharge between the image portion of the latent image carrier and the transfer medium but generate discharge between the non-image portion of the latent image carrier and the transfer medium.

Abstract: Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit; a transferring unit; and a control unit that performs an image forming process by controlling the latent image carrier, the charging unit, the latent image forming unit, the developing unit and the transferring unit, wherein, during execution of the image forming process, the latent image carrier circulates by passing through the charging position, the developing position and the transferring position in a state in which at least one of toner, which is charged with a polarity opposite to the regular charging polarity, and external additive agent, which is separated from the toner and charged with a polarity opposite to the regular charging polarity, is distributed and adhered to the surface of the latent image carrier.

Abstract: Provided is an image forming apparatus including: a latent image carrier; a charging unit; a latent image forming unit; a developing unit; a transferring unit; and a cleaning unit, wherein a voltage of the non-image portion of the latent image carrier is Vo, a voltage of the developing bias at the time when a force generated to bias the toner charged with the regular charging polarity in a direction from the latent image carrier to the toner carrier is maximum is Vmax, and a voltage of the developing bias at the time when a force generated to bias the toner charged with the regular charging polarity in a direction from the toner carrier to the latent image carrier is maximum is Vmin, in the developing position, an equation |Vmax?Vo|>|Vmin?Vo| is satisfied.

Abstract: An image forming apparatus is provided, which controls an appropriate developer amount for a desired image so that an image defect such as an unclear font or a white area is prevented, resulting in a stable image formation for a long term. A developer regulating member has a resistance value varying depending on a voltage to be applied. A control device changes over the voltage to be applied to the developer regulating member during the image formation according to image information and changes a potential difference between the developer carrying member and the developer regulating member.

Abstract: An image forming apparatus includes a developer bearing member for transporting developer to an opposing position opposing an image bearing member. Regularly-disposed concave sections are formed on a surface of the developer bearing member. An alternating voltage that includes a first voltage for moving developer from the developer bearing member toward the image bearing member and a second voltage for moving developer from the image bearing member toward the developer bearing member is applied to the developer bearing member. A cycle period of the alternating voltage is smaller than or equal to a minimum width of the concave section in a circumferential direction of the developer bearing member divided by a moving velocity of a surface of the rotating developer bearing member.

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: An image forming apparatus includes a photosensitive member, a developing roller, a toner supply roller, and a charging member. The toner supply roller supplies single-component non-magnetic toner to the developing roller for developing a latent image formed on the photosensitive drum. In a toner cleaning mode, the toner supply roller removes the toner from the developing roller. To this effect, the charging member charges up the toner held on the developing roller. A bias circuit and a controller are further provided, wherein the bias circuit applies bias voltages to the developing roller, supply roller, and charging member, and the controller controls the bias circuit to produce the bias voltages such that a potential difference between the charging member and the supply roller is greater than a potential difference between the developing roller and the supply roller in the toner cleaning mode.

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: An object of the present invention is to provide an image forming apparatus and a method for forming an image that are capable of controlling the consumption of opposite polarity particles and suppressing the reduction of toner charge amount due to the carrier deterioration and can form high quality images over a long period of time even in the case where large quantities of images with small image area ratio are printed. The image forming device includes a developer further including the opposite polarity particles, a developer carrying member, a toner carrying member, and a voltage applying section for applying bias voltage overlapped with alternating current between the toner carrying member and the image carrying member, wherein the bias voltage overlapped with alternating current is a vibrating waveform including a trapezoidal wave, or a vibrating waveform in which a blank is inserted during application of a reverse development side voltage component.

Abstract: A high voltage power supply apparatus according to the present invention is a high voltage power supply apparatus that applies a bias voltage at least to a developing roller of a developing unit, the apparatus comprising: a transformer that increases an AC voltage and includes a main winding and a sub winding on the secondary side thereof; a first capacitor whose first end is connected to a common connection point between the main and sub windings; a second capacitor whose first end is connected to one end of the sub winding which is not the common connection point side; a zener diode whose both ends are connected to the second end of the first capacitor and second end of the second capacitor; and a DC voltage application section that applies a DC voltage to the zener diode, wherein a voltage generated in the second end of the first capacitor is used as a voltage to be applied to the developing roller.

Abstract: Developer is to be used in an image forming apparatus of an electro-photography type, in which a developer supporting member attaches the developer to a static latent image supporting member for developing a static latent image. The developer includes an outer additive; and base particles. Further, the developer has a charge amount Q1 before the image forming apparatus performs a continuous printing operation and a charge amount Q2 after the image forming apparatus performs the continuous printing operation so that a ratio of Q1 to Q2 (Q1/Q2) becomes between 0.81 and 0.94.

Abstract: An image forming apparatus includes a developer bearing member configured to bear a developer to develop a latent image, a developer regulating member configured to regulate an amount of the developer carried on the bearing member, a voltage application unit that can apply a plurality of direct current voltages of different values between the bearing member and the regulating member, and a current detection unit that can detect a plurality of direct currents of different values flowing in the regulating member when the voltage application unit applies the plurality of direct current voltages, wherein the image forming apparatus sets a direct current voltage value Vb applied by the voltage application unit when developing the latent image, so that the following expression is satisfied: |Vb|>|Vbmin|, where Vbmin indicates a direct current voltage value when the direct current detected by the current detection unit is a minimum value.

Abstract: An image forming apparatus includes a developer carrying member to which a developing bias is applied. A frequency f of a developing bias waveform, a developing area S1 which is a time-integrated value of a difference between a voltage value of the developing bias and a solid electrostatic image potential VL in a developing period of the developing bias, a collecting area S2 which is a time-integrated value of a difference between the voltage value of the developing bias and VL in a collecting period of the developing bias, and a developing contrast value Vcon are used for defining a range of a value of the developing bias frequency f, a range of a value of a voltage change rate ? at VL during transition of the developing bias voltage value from a developing-side voltage to a collecting-side voltage, and a range of a value represented by the formula: {(S1?1.28×S2)×f/Vcon}×exp(?2.0×10?5×f/Hz).

Abstract: An image forming apparatus, for example, that is capable of accurately writing information into a developing unit or the like having an element is achieved. An image forming apparatus comprises: an attach/detach section to and from which a developing unit having an element into which information can be written and a developer containing section can be attached and detached; a photoconductor on which a latent image can be formed; a writing member for writing information into the element; and an AC voltage supply section for supplying an AC voltage. During a period from a start to an end of an image forming process, the writing member writes information into the element of the developing unit attached to the attach/detach section when the AC voltage supply section is not supplying an AC voltage.

Abstract: An image forming apparatus including a power supply unit which supplies high voltage AC power, a developing unit having at least one developing roller to receive first AC power from the power supply unit to supply a developer to an image receptor, and an erasing unit to receive second AC power to attenuate high frequency noise of the developing unit.

Abstract: An aspect of the invention provides a developing unit that comprises: a developer; an image carrier on which an electrostatic latent image is formed; a first developer carrier configured to develop the electrostatic latent image formed on the image carrier by causing the developer to attract to the electrostatic latent image; a first restriction member configured to be in press-contact with the first developer carrier; a second developer carrier configured to abut to the first developer carrier, and to form a developer layer on the second developer carrier; a second restriction member configured to abut to the second developer carrier; and a supplying member configured to supply the second developer carrier with the developer.

Abstract: Developing bias is set as follows. An electric field intensity between a developing roller and a photoconductor is set to cause normally-charged toner to fly in an image area and not to cause the toner to fly in a background area. Thus, the normally-charged toner does not fly in the background area. The normally-charged toner caused to fly is therefore unlikely to flick low-charged toner and oppositely-charged toner. The low-charged toner and the oppositely-charged toner will not adhere to the background area and cause image fogging. Accordingly, an image forming apparatus can be provided to prevent the low-charged toner and the oppositely-charged toner from adhering to the background area of an electrostatic latent image on the photoconductor and to avoid the occurrence of image fogging in the background area on a printed material.

Abstract: An image forming apparatus includes an image carrier that carries an electrostatic latent image on a surface thereof, a toner carrying roller that is disposed to face the image carrier and rotates in a predetermined rotation direction with charged toner carried on a surface thereof so as to transport the toner in an opposing position for facing the image carrier, and a bias applying unit that develops the electrostatic latent image with the toner by applying an AC voltage as a developing bias to the toner carrying roller. In addition, periodical concavo-convexes that are formed of a plurality of convex portions arranged at a constant pitch in a circumferential direction and concave portions that surround the plurality of convex portions are formed on the surface of the toner carrying 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: A developing cartridge that includes: a developing roller having a developing roller gear and a driving force transmitting unit; and an electrode member for applying a bias to a developing roller shaft. A direction of a driving force applied to the developing roller gear at an engagement portion between the developing roller gear and a transmission gear when the developing roller gear and the transmission gear rotate, and a direction of a force applied to the electrode member at a contact portion between a power supply member and the electrode member when the power supply member presses on the electrode member are substantially equal to a direction orthogonal to the axial direction of the developing roller shaft.

Abstract: There is provided an image formation device comprising an electrostatic latent image holding body having an latent image formation surface on which an electrostatic latent image is formed, a developer supply unit to supply developer to the electrostatic latent image holding body to form, on the latent image formation surface, a developer image corresponding to the electrostatic latent image; a developer transfer unit located to face the electrostatic latent image holding body to transfer the developer image to a developer image holding surface; and a contacting member to contact the latent image formation surface at a stage which is after formation of the developer image and before transfer of the developer image to the developer image holding surface.

Abstract: An image-forming device includes an image acquiring unit, an image forming unit, a determining unit, and a controller. The image acquiring unit acquires image data for one page. The image forming unit forms an image based on the image data. The image forming unit includes a developing roller, a supply roller, and a bias applying unit. The developing roller carries a developer. The supply roller supplies the developer to the developing roller. The bias applying unit applies a first voltage between the developing roller and the supply roller in a first mode, and applies a second voltage between the developing roller and the supply roller in a second mode. The determining unit determines whether the image data includes a part having density greater than or equal to a prescribed density.

Abstract: A developing device facing an image carrier and including a developer carrier, a developer flying control member, and a development-noise control member. The developing device develops an electrostatic image formed on the image carrier by causing the developer to fly from the developer carrier to the image carrier upon an application of an alternating-current bias to the developer carrier. Noise produced by the development-noise control member vibrated by an oscillating electric field of the alternating-current bias is smaller than a noise produced by the developer flying control member vibrated by the oscillating electric field.

Abstract: A developing device facing an image carrier and including a developer carrier, a developer flying control member, and a development-noise control member. The developing device develops an electrostatic image formed on the image carrier by causing the developer to fly from the developer carrier to the image carrier upon an application of an alternating-current bias to the developer carrier. Noise produced by the development-noise control member vibrated by an oscillating electric field of the alternating-current bias is smaller than a noise produced by the developer flying control member vibrated by the oscillating electric field.

Abstract: To prevent image defects such as fog and irregularities caused by the accumulation of the oppositely charged toner by flying the toner toward a photoreceptor to compulsorily consume the toner even though the toner is oppositely charged toner having a small charged amount. A potential difference between the photoreceptor and the development roller is set at a value at which the normally charged toner on the development roller can be flown toward the photoreceptor in the development phase at the time of compulsorily consuming the toner, and this potential difference is set at a value at which the flown normally charged toner can be returned to the development roller in the recovery phase.