Abstract: A developing device includes an applying portion for applying a bias at a first voltage value and a first frequency, to a toner bearing member during a development period in which toner particles are supplied to an image bearing member. A controller executes a removal control to remove attached matter adhering to a bearing surface of the toner bearing member during a non-development period. Upon executing the removal control, the controller first causes residual toner particles to separate from the bearing surface. Subsequently, the controller controls the applying portion to cause a second bias at a second voltage value higher than the first voltage value or at a second frequency higher than the first frequency to be applied to the toner bearing member while bringing a developer layer on a developer bearing member into contact with the bearing surface.

Abstract: An image forming apparatus includes a transfer bias set up section and a developing bias set up section. The transfer bias set up section sets a transfer bias applied to each transfer member so that the transfer bias applied to a transfer member corresponding to a photosensitive member on the most downstream side is greater than a transfer bias applied to a transfer member other than this transfer member. The developing bias set up section sets a developing bias applied to each developing member to a first developing bias in a single-side printing mode, and sets up the developing bias applied to each developing member in formation of an image on a first surface and in formation of another image on a second surface to a second developing bias lower than the first developing bias when the image formed on the second surface is a color image.

Abstract: A developing device and image forming apparatus are provided, wherein high quality images, in which generation of development hysteresis (ghost image) is alleviated, are obtained over a long period using a hybrid development method including a toner-supplying developer supporting member and a toner-collecting developer supporting member. Bias voltage is applied in the direction in which the toner is supplied to the toner supporting member in the toner supply region and the toner collection region of the toner-supplying developer supporting member and the toner-collecting developer supporting member respectively so that the toner collecting capability in the toner collection region is higher than the toner collecting capability in the toner supply region.

Abstract: Certain embodiments provide an image forming apparatus including: an image carrier; a latent image forming unit; a developing unit; a fixing unit; a toner cartridge; a battery in the toner cartridge; a temperature sensor in the toner cartridge driven by the battery; a first controller which causes the temperature sensor to measure an ambient temperature periodically in the toner cartridge and be supplied with power from the battery; a recording medium which is provided in the toner cartridge and records a result of measurement by the temperature sensor in timing controlled by the first controller; and a second controller which reads out information recorded in the recording medium, and changes an operating condition of the latent image forming unit, the developing unit and the fixing unit according to a state of preservation of the supply of toner, based on the information.

Abstract: Certain embodiments provide an image forming apparatus comprising an image forming part, a detection part, an arithmetic part, a storage device and an image quality maintaining control part. The image forming part forms an image quality maintaining adjustment pattern on a transfer belt to convey a sheet. The detection part detects the image quality adjustment pattern. The arithmetic part calculates, based on a detection result of the image quality maintaining adjustment pattern obtained by the detection part, image quality maintaining information for forming an image of desired image quality. The storage device stores the image quality maintaining information before the image forming apparatus transitions to a sleep mode. The image quality maintaining control part reads the image quality maintaining information from the storage device and controls the image forming part based on the read image quality maintaining information before the image forming apparatus returns after the sleep mode is released.

Abstract: An apparatus (100) and method (200) that evaluates printing apparatus cleaner performance. The method can be performed in a printing apparatus that can include an intermediate transfer belt (150), an intermediate transfer belt sensor (155), a developer (115), a photoreceptor (110), and a photoreceptor cleaner (120). The method can include placing (220) marking material on the photoreceptor using the developer. The method can include cleaning (230) the marking material on the photoreceptor using the photoreceptor cleaner. The method can include transferring (240) the marking material to the intermediate transfer belt. The method can include sensing (250) marking material on the intermediate transfer belt using the intermediate transfer belt sensor.

Abstract: Disclosed are printing methods, apparatus and systems for developing a latent image recorded on a surface, for example, a photoreceptor with developer material. According to an exemplary embodiment, the development method applies a development field voltage between a development station donor member and a development station transport member as a function of a humidity measurement associated with the developer material, the humidity measurement providing a surrogate tribo measurement of the developer material.

Abstract: An image forming apparatus including toner image forming means for forming a having chromatic toner image a transparent toner image; fixing means for heating and fixing the non-transparent toner image and the transparent toner image on recording material; glossiness detecting means for detecting a glossiness of an area in which the non-transparent toner image and the transparent toner image are overlaid and fixed; control means for controlling an amount of the transparent toner, per unit area, on the recording material on the basis of a result of detection by the detecting means.

Abstract: An image forming apparatus includes: an image formation control unit for forming print images on an image carrier and for forming a reference toner pattern having a predetermined size between the print images formed on the image carrier; a reference image density detecting unit for detecting a image density of the reference toner pattern; and an image forming condition adjusting unit for adjusting an image forming condition based on the image density detected by the reference image density detecting unit. If a toner amount of one or plurality of the print images is greater than a predetermined value, the image formation control unit prevents any further adjustment operation performed by the image forming condition adjusting unit.

Abstract: An image forming apparatus includes a rotatable image bearing member configured to bear an electrostatic latent image, a plurality of development devices including a developer bearing member configured to bear a developer for developing the electrostatic latent image, a rotatable development device supporting member configured to support the plurality of development devices. In the image forming apparatus, the developer bearing member is configured to execute development while contacting the image bearing member at a development position via the developer, rotating in the same direction as rotating direction of the image bearing member at the development position, and rotating at a speed faster than a surface speed of the image 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; 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 includes an image holder, a latent image forming unit, and a developing unit, the developing unit including a developer holder that is disposed to face the image holder and holds developer. Also included is a developer container, replenishing unit that replenishes new developer to the developing unit, a discharge unit that discharges the developer, a calculation unit that calculates an image area coverage of a toner image formed on the image holder, an obtaining unit that obtains a potential difference between the developer holder and the image portion on the image holder, and a controller that increases a discharge amount of the developer, when the image area coverage calculated by the calculation unit is smaller than a predetermined reference image area coverage, and the potential difference obtained by the obtaining unit is larger than a predetermined reference potential difference.

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: An image forming apparatus forms images. A developer bearing body receives a first voltage and supplies developer to the electrostatic latent image formed on an image bearing body. A supplying member receives a second voltage and supplies the developer to said developer bearing body. A detector detects at least one of an environmental condition, e.g., temperature and humidity outside of an apparatus and an environmental condition e.g., temperature inside of the apparatus. A controller controls the difference between the first voltage and the second voltage in accordance the environmental conditions. The controller makes a decision to determine whether the outside temperature is not lower than a first reference, whether outside humidity is not higher than a second reference, and whether inside temperature is not lower than a third reference. If the above criteria are met, the controller decreases the absolute value of the difference.

Abstract: An image forming apparatus according to an embodiment includes a charging device that charges an electric charge to an image carrier, a developing device supplying the image carrier with a developer, and a transfer device that transfers a toner image formed on the image carrier by a developing device onto a recording medium. The apparatus further includes a control unit, discriminates between a first mode of forming an image on a first recording medium of a first thickness and a second mode of forming an image on a second recording medium thinner than the first recording medium to control a developing contrast electric potential, and controls a magnitude of the developing contrast electric potential in the second mode so as to be lower than the first mode.

Abstract: A developing device includes: a developer containing a toner and a carrier; a first transporting member placed at an opening portion of a developer vessel used for housing the developer; a second transporting member that faces the first transporting member with a first area interposed therebetween, and also faces an electrostatic latent image-supporting member with a second area interposed therebetween; a first electric-field-forming unit that forms a first electric field between the first transporting member and the second transporting member; and a second electric-field-forming unit that forms a second electric field between the second transporting member and the electrostatic latent image-supporting member. An image-forming apparatus includes the above-mentioned developing device.

Abstract: According to one embodiment of the present invention, an image forming apparatus includes: an image formation unit; an image formation frequency count unit; a first control unit; a target contrast potential determination unit, and a second control unit. The image formation unit forms an image pertaining to a print job input from an external on an image carrier. The image formation frequency count unit counts an image formation frequency of the image in the image formation unit. The first control unit controls the image formation unit, and executes a first image stabilization mode for adjusting a development bias voltage on the basis of a concentration of a pattern image formed on the image carrier.

Abstract: An image forming apparatus includes a control device that calculates a developing ability of the developing device based on a detection value detected by an optical detection device from the plural toner patches. The control device adjusts an image formation condition based on the calculated developing ability. A factor detection device is provided to detect a contributing factor that causes the developing ability to largely change after the last adjustment of the image formation condition. The control device controls image formation such that when the factor detection device does not detect the contribution factor and a developing ability calculated this time is different from that calculated last time (as to a part of the plural toner patches), the plural toner patches are formed based on a prescribed fixed image formation condition so that an attraction amount of toner attracting to the plural toner patches enter a prescribed range detectable for the optical detection device.

Abstract: An image forming apparatus includes a latent image holder that holds a latent image; a developing unit that contains developer including toner particles and carrier particles, develops a latent image with the toner particles, and forms a toner image; a voltage applying unit that applies a voltage to the developing unit; a toner concentration detection unit that detects a toner concentration that is a proportion of the toner particles to the developer contained in the developing unit; and a setting unit that sets a setting value of the voltage on the basis of the toner concentration detected by the toner concentration detection unit, the voltage being applied by the voltage applying unit to the developing unit, wherein a difference between an upper limit and a lower limit of the set value increases as the toner concentration increases, the set value being set by the setting unit.

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 comprises an image carrier, a developing unit, a supply unit and a control unit. A developing unit visualizes an electrostatic latent image formed on a surface of the image carrier, using a developing material. A supply unit supplies a periodic wave as a developing bias to the developing unit. A single period of the periodic wave is formed by a first time period and a second time period. In the first time period a voltage in which a DC voltage and an AC voltage are superimposed is applied. In the second time period only a DC voltage is applied. A control unit changes the duration of the second time period according to the amount of electrostatic latent images that have been formed in succession.

Abstract: In case new and old toners may be mixed, a developing bias is set as follows. The time is first clocked. The number of times toner is replenished from a hopper into a buffer for a clocked period is counted. If a replenishment amount per clock time is a threshold value or higher, considering that new and old toners are mixed, the setting of the developing bias is changed. An electric field intensity between a developing roller and a photoconductor is set to cause normally-charged toner to fly in an image area but not to fly in a background area. No image fogging is therefore generated in the background area. Thus, an image forming apparatus and method capable of preventing low-charged toner and oppositely-charged toner generated by mixing of new and old toners from adhering to the background area of an electrostatic latent image on the photoconductor, thereby avoiding generation of image fogging.

Abstract: Upon receiving a request to control developing bias voltage, first and second square-wave signal output units output first and second square-wave signals, respectively. When a rising edge of the first square-wave signal coincides with a rising edge of the second square-wave signal, the rising edge of the second square-wave signal is advanced with respect to the rising edge of the first square-wave signal. When a falling edge of the first square-wave signal coincides with a falling edge of the second square-wave signal, the falling edge of the second square-wave signal is delayed with respect to the falling edge of the first square-wave signal. Subsequently, a voltage-controlling square-wave signal for controlling developing bias voltage is generated based on the first and second square-wave signals.

Abstract: An image forming apparatus includes data conversion, charging, exposure, developer supply, image density calculation, determination and voltage change mechanisms. The data conversion mechanism converts image data into printing data. The charging mechanism charges an image carrier. The exposure mechanism forms an electrostatic latent image on the image carrier based on the printing data. The developer supply mechanism supplies a developer to the image carrier having the electrostatic latent image with an electrostatic force. The image density calculation mechanism calculates an image density of an image having a predetermined number of lines in the printing data. The determination mechanism determines whether a voltage to be applied to the developer supply mechanism is changed based on a calculation result by the image density calculation mechanism. The voltage change mechanism changes the voltage to be applied to the developer supply mechanism based on a determination result by the determination mechanism.

Abstract: An image forming apparatus has a job-content recognition device for judging whether a number inputted as the number of print copies to be made is larger or smaller than a predetermined reference value; a print-data recognition device for judging whether or not inputted print data include image data and/or graphic data; and a control device for controlling executions of image stabilization control in a printing section. The control device sets a predetermined period as intervals among executions of the image stabilization control, and sets a period shorter than the predetermined period as the intervals among executions of the image stabilization control when the number inputted as the number of print copies to be made is larger than the predetermined reference value and also the inputted print data include image data and/or graphic data.

Abstract: A developing apparatus including a developing container for containing developer, the developing container having an opening portion, a developer carrying member for carrying the developer at the opening portion, a detecting member for detecting a developer amount, the detecting member detecting a capacitance between the developer carrying member and the detecting member, and a force receiving portion for receiving a force and moving the developing container between a first position in which a developing operation is performed by the developer carrying member and a second position in which the developing operation is not performed, wherein the capacitance can be detected in the second position, and the detecting member is a rotatable developer supplying member for supplying the developer to the developer carrying member, the developer supplying member including a foam layer in which the developer can enter.

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: An image forming apparatus includes an image carrier that is electrically charged and exposed to light to form a latent image that is developed by liquid developer. A first squeezing roller that is held in contact with the image carrier carrying a developed image bears bias voltage Vs1. A second squeezing roller that is held in contact with the image carrier squeezed by the first squeezing roller bears bias voltage Vs2. The image is transferred to a transfer member that is held in contact with the image carrier squeezed by the second squeezing roller. The absolute values of the bias voltages Vs1 and Vs2 have a relationship of |Vs1|>|Vs2|.

Abstract: A developing device includes: a plurality of developer retaining bodies that retain developer and rotate, and that respectively convey the developer, which is supplied to each of the developer retaining bodies from a developer supply section, to an image bearing body that rotates and bears a latent image; and a speed changing unit that is adapted to change a rotation speed of at least one of the developer retaining bodies excluding a developer retaining body that is furthest downstream side in a direction of rotation of the image bearing body.

Abstract: An image forming apparatus which predicts VL fluctuations of a photosensitive drum in consideration of a double-sided print mode, and performs an image formation control based on the prediction, and thus always obtains a stable density image. The image forming apparatus performs an appropriate image formation control by controlling an image forming condition based on a photosensitive member rotation time, a photosensitive member stop time, a temperature of an atmospheric environment, an absolute humidity of the atmospheric environment, and whether an image formation that precedes a subsequent image formation is performed in single-sided printing or double-sided printing.

Abstract: A developing unit has a voltage-applicator (80) to apply a developing bias voltage to a developing roller (72). The voltage-applicator (80) applies the developing bias voltage for a first duration to apply an AC voltage having a rectangular waveform, and a second duration to stop applying the AC voltage. The AC voltage has a duty ratio of 50% or more in a direction for causing toner to develop an electrostatic latent image. The number of cycles of the AC voltage in the first duration is two or more, and the AC voltage has a voltage in a direction for pulling the toner back to the developing roller, just before transition to the second duration. The developing unit suppresses occurrence of image unevenness due to a fluctuation in developing gap. Thus, an image forming apparatus equipped with the developing unit forms a high-quality image while suppressing image unevenness.

Abstract: An image forming apparatus including a photosensitive member, a charging apparatus to charge a surface of the photosensitive member when applied with a charging voltage, and an exposure apparatus to expose the surface of the photosensitive member after being charged to form an electrostatic image. A developing apparatus attaches a developer to the electrostatic image and develop the electrostatic image as a developer image when applied with a development voltage. An environment measuring apparatus measures information regarding temperature and a time information obtaining apparatus obtains information regarding a photosensitive member rotation time that represents a time during which the photosensitive member is rotated, and information regarding a photosensitive member stop time that represents a time during which the photosensitive member is stopped. A control apparatus controls an image formation condition based on a control mode.

Abstract: An image forming apparatus comprising a latent image carrier for supporting a latent image, a charging unit for charging the latent image carrier, a developing unit for developing the latent image supported by the latent image carrier which has a developing member for supporting a liquid developer containing a toner and a carrier liquid, and to which a developing bias is applied, a first optical density detector for detecting the toner optical density in the liquid developer supported by the latent image carrier developed by the developing member, a squeeze unit for squeezing the latent image carrier which has a squeeze member brought into contact with the latent image carrier for which toner optical density has been detected by the first optical density detector, and a second optical density detector for detecting the toner optical density of the liquid developer supported by the latent image carrier squeezed by the squeeze member.

Abstract: In a RAM are stored a first deflection information table representing the relationship between the rotation amount and the deflection amount of a photosensitive element, a second deflection information table representing the relationship between the rotation amount and the deflection amount of a developing sleeve, a writing sensitivity information table representing the relationship between the rotation amount of the photosensitive element and latent image writing sensitivity, and an image forming condition information table representing the relationship between the rotation amount and laser power. An information input unit is provided to input the respective tables. During a print job, laser power is changed on the basis of the image forming condition information table, and laser power which causes deviation in an opposing direction is calculated on the basis of information input in a standby state to update the image forming condition information table.

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: An image forming apparatus includes a latent image bearing body that bears a latent image, a charging member applied with a charging voltage and configured to charge a surface of the latent image bearing body, a developer bearing body applied with a developing voltage and configured to develop the latent image with a developer, a developer regulating member applied with a regulating-member-application voltage and configured to form a layer of the developer on the developer bearing body, and a voltage switching unit configured to switch the regulating-member-application voltage. In a non-image-forming period, the voltage switching unit switches the regulating-member-application voltage from a voltage set for an image forming period to a different voltage.

Abstract: A image forming apparatus includes a photosensitive drum having a high-lubricity state layer. In an initial rotation operation performed after mounting a process cartridge, in a main assembly of the image forming apparatus, a process cartridge in which lubricating particles are not applied in a contact area between a fresh cleaning blade and the photosensitive drum, toner is supplied only by application of a developing bias after the photosensitive drum and a developing sleeve are driven to supply and stagnate the toner in the contact area between the cleaning blade and the photosensitive drum.

Abstract: An image forming apparatus has a pair of spacedly opposed first and second bearing members, in which a powder developer material is moved from the first bearing member to the second bearing member. The apparatus also has an electric field generator. The generator forms an electric field between the first and second bearing members and outputs a first voltage and a second voltage alternately. The first voltage generates, between the first and second bearing members, a first electric field electrically forcing the developer material from the first bearing member toward the second bearing member. The second voltage generates between the first and second bearing members a second electric field electrically forcing the developer material from the second bearing member toward the first bearing member.

Abstract: An image forming apparatus includes an alternating-current high-voltage power supply generating an alternating-current bias for detection of the remaining amount of toner. The alternating-current high-voltage power supply includes a piezoelectric transformer, a piezoelectric-transformer driving unit, a piezoelectric-transformer driving-signal generating unit, a voltage detecting unit, a voltage setting unit, and an controlling unit that feeds back a difference signal between a detection level signal supplied from a detection signal detecting unit and a setting signal supplied from the voltage setting unit to the piezoelectric-transformer driving-signal generating unit to control an output voltage from the piezoelectric-transformer.

Abstract: The present invention provides a method and apparatus for forming an image. A controller manages a charger and a developing bias voltage to increase an absolute value of the charging voltage to an image-bearing member and an absolute value of a developing bias voltage to a developer-bearing member to predetermined values in a plurality of steps. The controller controls the developing bias voltage applied to the developer-bearing member; wherein the following relation holds in each of the plurality of steps: |VD|>|Vi|, where VD represents a developing bias voltage applied to the developer-bearing member and Vi represents a charged potential of the image-bearing member. This invention is especially useful for mono-component development using DC voltage as a development driving mechanism.

Abstract: An image forming device includes a toner supplying unit to supply the toner to a storage unit, a mixer to supply developer in the storage unit to a developing roller, a developer sensor to detect the amount of developer on the surface of the developing roller, a toner concentration sensor to detect toner concentration in the developer stored in the storage unit, and a control unit to adjust at least one of a developing bias and a rotation speed of the mixer based on a value detected by the developer sensor and a value detected by the toner concentration sensor, such that a printed image has uniform density.

Abstract: An image forming apparatus includes an image supporting member for forming a developer image; a developing unit for forming a developer layer and forming the developer image on the image supporting member using developer of the developer layer; a developer supplying unit for supplying the developer to the developing unit; an image density detection unit for detecting an image density of the developer image; and a control unit for controlling a voltage applied to the developing unit and the developer supplying unit. The control unit corrects the voltage applied to at least one of the developing unit and the developer supplying unit according to the image density detected with the image density detection unit.

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: An image forming apparatus that includes: a photoconductive drum; a developing roller that is arranged opposite the photoconductive drum and that carries toner; a detecting portion that detects an occurrence of electrical discharge between the developing roller and the photoconductive drum; a control portion that controls the apparatus, that receives an output of the detecting portion and then recognizes the occurrence of the electrical discharge; a direct voltage applying portion that is connected to the developing roller; and an alternating voltage applying portion is disclosed herein.

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 developing device includes: a developing roller on the surface of which intersecting inclined grooves are formed by rolling working; and a seal member which comes into contact with the developing roller, wherein ridge portions of a convex portion surrounded by the inclined grooves of the surface of the developing roller are formed such that rotational resistance due to the contact of the seal member on the downstream side of a rotation direction opposite to a rotation direction of the developing roller at the time of development is larger than rotational resistance due to the contact of the seal member on the downstream side of a rotation direction of the developing roller at the time of development, and at the time of refreshing of the seal member, the developing roller is rotated in the opposite direction to a direction at the time of development.

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: The development apparatus that develops an electrostatic latent image formed on an image carrier comprises: a developer roller operable to carry toner on a circumferential surface thereof and develop the electrostatic latent image using the toner; a supply roller operable to perform toner supply to the developer roller; a voltage applier operable to apply a bias voltage V1 to the developer roller and apply a bias voltage V2 to the supply roller; and a controller operable to control the voltage applier in a toner compulsive consumption mode so that a value obtained by subtracting an average S2 of the bias voltage V2 per unit time from an average S1 of the bias voltage V1 per unit time indicates the same polarity as a normal charging polarity of the toner. Here, the toner compulsive consumption mode performs development to compulsively consume the toner carried on the circumferential surface of the developer roller.

Abstract: A charge bias causing the surface potential of a photosensitive drum to be lower than that in image formation is applied to a charge roller during a period in which the stop position of a rotary is moved from an unknown state to a home position to cause a developing bias to be applied to a developing roller to be smaller than that in the image formation.

Abstract: A control unit controls a device that executes an image forming process, compares changes of each toner adhesion amount in an image-density-detection pattern image when a developing-bias control condition is changed, with respect to a toner adhesion amount in an image-density-detection pattern image in a normal status, performs a malfunction-occurrence prediction process according to the degree of each change of the densities, and displays the result.