Abstract: An image forming apparatus includes a sensor that is configured to detect a property of a developer material, a transport unit that is operatively in contact with the developer material and that is configured to move the developer material toward a recording medium, and a controller that receives the property of the developer material from the sensor unit and sets a voltage of the transport unit, wherein the voltage is determined based on the property of the developer material received from the sensor.

Abstract: The present invention provides an image forming apparatus, including: an image bearing member; a development device that develops an electrostatic latent image formed in the image bearing member with a toner; a detection portion that detects information on humidity within the apparatus body; a time measuring portion that acquires a time information; a humidity sensor that detects humidity around the development device; and a controller that sets a parameter about an image density formed in a transfer material, based on history information about the information on humidity within the apparatus body and the time information detecting the information on humidity and based on information acquired by the acquisition portion.

Abstract: A developing device includes a developing roller, a magnetic roller, a capacitor, a transformer, a switching section, a control section, a temperature detecting section, and a storage section. When changing the duty ratio of a control signal in multiple sequential steps, the control section determines the resonance period based on the temperature and temperature characteristic data and changes the duty ratio of the control signal to the next step during a changing time slot which is one of the first and second halves of a period of voltage fluctuation of the capacitor based on the determined resonance period, the one half in which the current flowing through the switching section is smaller than in the other half of the period.

Abstract: A wet-type image forming apparatus includes an image bearing member, a developer bearing member for bearing liquid developer containing toner and carrier liquid on the circumferential surface thereof, a bias applying unit for applying a developing bias to the developer bearing member, a first charging unit for charging the toner in the liquid developer to a first polarity before supplying the liquid developer to the image bearing member, and a second charging unit for reversely charging the toner in residual liquid developer remaining on the circumferential surface of the developer bearing member to a second polarity opposite to the first polarity after the development process. When VD denotes the developing bias and V0 denotes the surface potential of the residual liquid developer when the reverse charging is not performed, a surface potential V of the residual liquid developer after reverse charging satisfies the equation: 0.1?(VD?V)/(V0?VD)?1.0.

Abstract: An image forming apparatus includes a toner carrying member for carrying a toner; an image carrying member on which a toner image is formed with the toner; and a plurality of divided electrode portions provided at a position in which the electrode portions oppose the toner carrying member via the image carrying member interposed therebetween. The electrode portions are supplied with a voltage on the basis of image information to move the toner between the toner carrying member and the image carrying member thereby to form the toner image. The electrode portions includes a first electrode portion for forming an image portion and a second electrode portion, adjacent to the first electrode portion, for forming a non-image portion.

Abstract: Various methods, devices and techniques for improving image quality for an image forming device are disclosed. For example, improved image quality can be had for an image forming apparatus having a first image forming unit including a first image carrier and a first developer carrier in contact with the first image carrier at a first pressure, and the first image carrier carries a first developer having a first charging characteristic, and a second image forming unit including a second image carrier, and a second developer carrier in contact with the second image carrier at a second pressure, greater than the first pressure, and the second developer carrier carries a second developer having a second charging characteristic. The first pressure and the second pressure are preset based on the first charging characteristic and the second charging characteristic.

Abstract: A power source includes a charging voltage generation unit configured to generate a charging voltage to charge an image bearing member, a developing voltage generation unit configured to generate a developing voltage to develop an electrostatic latent image formed on the image bearing member, a control unit configured to control an output from the developing voltage generation unit, and a correction unit configured to correct an operation of the control unit based on an output from the charging voltage generation unit.

Abstract: A developing device includes a developing roller, a magnetic roller, a capacitor, a transformer, and a control signal generating unit. The developing roller carries toner. The magnetic roller performs supply of toner to the developing roller and removal of toner from the developing roller. The transformer includes a primary side to which a capacitor is connected and a secondary side from which an AC voltage is output and applied to the developing roller. The control signal generating unit inputs a control signal to the capacitor and adjusts a DC bias value of the control signal so that a DC component of the control signal is the same before and after the change of the duty ratio of the control signal.

Abstract: An image formation apparatus includes an exposure unit to form an electrostatic latent image with image dots on a rotatable image carrier by exposing the image carrier to irradiation light, a development unit to form a developer image by attaching a developer to the electrostatic latent image, a voltage supply unit to supply the development unit with a development voltage, a cleaning unit to clean up the developer left on the image carrier after the development, and a developer discard amount controller to control an amount of the developer to be forcibly attached to the image carrier based on a total rotation number of the image carrier if the number of image dots printed during a prescribed number of rotations of the image carrier is smaller than a reference value, and to forcibly attach the controlled amount of the developer to the image carrier to discard the developer.

Abstract: A color electrophotographic image forming apparatus includes a supporting member that supports a plurality of electrophotographic photosensitive drums and is movable between an image forming position and a retracted position, a driving unit for driving the electrophotographic photosensitive drums, an intermediary transfer belt onto which images formed by developing the electrostatic latent images formed on the electrophotographic photosensitive drums are transferred, and a controller for controlling execution of image formation. The controller controls the image formation so as to provide, on the electrophotographic photosensitive drums, areas having a lowered absolute value of surface potential, and so as to stop driving of the electrophotographic photosensitive drums by the driving unit in a state that the areas are opposed to the intermediary transfer belt.

Abstract: In the case of a standard sized sheet, a first controller sets a linear velocity D of an image bearing member at a first velocity and sets a linear velocity S of a toner bearing member so that S/D, which is a ratio of the linear velocity S to the linear velocity D, has a first value and a second controller sets the thickness of the toner layer carried on the toner bearing member at a first layer thickness. In the case of a long sheet, the first controller sets the linear velocity D at a second velocity slower than the first velocity and sets the linear velocity S so that the S/D has a second value larger than the first value and the second controller sets the thickness of the toner layer at a second layer thickness smaller than the first layer thickness.

Abstract: The developing device includes a toner layer formation control unit instructing a voltage control unit to set a first voltage difference to form a toner layer on a surface of a toner supporting rotator, a stripping control unit that instructs the voltage control unit to, in a toner layer stripping mode, set a second voltage difference that moves substantially an entire amount of toner composing the toner layer to a developer supporting rotator, and a density detection unit detecting the toner density on a transfer member onto which a toner image is primarily transferred. When the toner remains on a surface of the toner supporting rotator, the stripping control unit causes the toner to fly to the surface of the image carrier, while outputting an instruction adjusting the second voltage difference to the voltage control unit in order to reduce the toner density detected by the toner density detection unit.

Abstract: An image forming apparatus includes a photosensitive drum; a first sleeve for carrying a developer containing toner and a carrier having a volume resistivity lower than that of the toner and for developing an image on the drum by rubbing the drum with the developer; a second sleeve for carrying the developer received from the first sleeve and for developing the image by rubbing the drum with the developer carried on the second sleeve; a voltage source for applying a developing bias voltage including a DC voltage component and an AC voltage component to the first sleeve and second sleeve; and a driving device for rotating the first sleeve at a peripheral speed higher than the drum and for rotating the second sleeve at a peripheral speed which is higher than the drum and which is lower than the first sleeve.

Abstract: A development device includes a developer bearer to carry by rotation developer to a development range facing a latent image bearer, and a developer regulator to adjust an amount of developer transported to the development range by the developer bearer. Multiple projections are formed in a surface of the developer bearer, and the developer bearer rotates in a reverse direction to a direction of rotation for image development while image development is not performed. The developer regulator includes a blade having a first end held by a regulator holder and a second end that contacts the multiple projections formed in the surface of the developer bearer and is disposed in a direction counter to the direction of rotation of the developer bearer for image development.

Abstract: An image forming apparatus has a first voltage application section for applying a first bias to a magnetic roller, a second voltage application section for applying a second bias to a developing roller, and a controller for controlling the voltages of the first and second voltage application sections and the driving/rotating of the magnetic roller and the developing roller. When no image formation is taking place, the controller can execute a toner collection mode in which, with the first and second biases set at the same potential and the second bias set lower than the voltage applied to an image carrying member, the magnetic roller is rotated in the direction reverse to that in which it is rotated during image formation.

Abstract: A developing device includes a developing roller, a magnetic roller, a capacitor, a transformer, and a switching portion. The magnetic roller supplies toner to the developing roller or takes off the toner from the same. The capacitor is connected to a primary of the transformer, and the developing roller is connected to a secondary of the same. During a period while the voltage between electrodes of the capacitor is changing, the switching portion changes the duty ratio in a predetermined second time slot in which current flowing in the switching portion is smaller than that flowing in a first time slot.

Abstract: An image forming apparatus includes an image bearing member and a developing device for developing an electrostatic latent image. The developing device includes a developer container, a rotatable developer carrying member, including a first electrode member; and a developer supplying member, including a second electrode member. The apparatus further includes a measuring device capable of measuring a remaining developer amount; and a replenishing device for performing a replenishing operation by rotating the developer supplying member while applying a DC bias between the first and second electrode members so that a value obtained by subtracting an electric potential of the second electrode member from an electric potential of the first electrode member has a polarity identical to a normal charge polarity of the developer. When the remaining developer amount measured is not more than a threshold, the replenishing operation is performed and the remaining developer amount is measured again.

Abstract: An image forming apparatus has: a photoconductive drum that rotates; a developing roller that carries toner to be charged and to which a first voltage application portion outputting an AC voltage is connected; a contact member that makes contact with the photoconductive drum to remove residual toner; a detection portion for detecting occurrence of electric discharge between the developing roller and the photoconductive drum; and a developing unit that feeds toner to the developing roller, that supports the developing roller opposite the photoconductive drum with a gap secured in between, and that feeds toner to the developing roller with prescribed timing and for a prescribed time during electric discharge detection.

Abstract: A developing device includes a development roller, a magnetic roller, a transformer, a switching portion, output control portion and a capacitor. The development roller is opposite a photoconductor drum. The magnetic roller performs, with a magnetic brush, the supply of a toner to the development roller and the removal of the toner. The transformer generates an alternating-current voltage applied to the development roller. The switching portion passes and interrupts a current to the transformer. The output control portion stepwise changes, when a duty ratio in switching is changed, the duty ratio a plurality of times from a first duty ratio to a second duty ratio. The capacitor has one end connected to the transformer and the other end connected to the switching portion.

Abstract: An image forming apparatus includes a developing section that includes a feed member having a groove, a developer carrier developing with liquid developer fed from the feed member, and a charging member charging the liquid developer carried in the developer carrier. An image carrier carries an image developed by the developing section. An optical sensor includes a light emitting section emitting light to the image developed in the image carrier. A first light receiving section receives light reflected from the image. A second light receiving section is disposed at a position different from that of the first light receiving section. A control section adjusts a developing bias applied to the developer carrier in response to an output signal of the first light receiving section, and controls a bias applied to the charging member by the output signals of the first and second light receiving sections.

Abstract: An image forming apparatus includes a rotatable photoconductor, a charging unit, an exposure unit to expose the photoconductor to reduce an electrical potential at the photoconductor, a developing unit to charge the toner held on a toner bearing member with friction and attract the toner to the exposed portion on the photoconductor by supplying a development voltage from a first power source and using an electrical potential difference between the toner bearing member and the photoconductor in the development area, a reverse development voltage controller to supply a reverse development voltage while a non-charged portion on the photoconductor passes the development area, and a developer reducing potential applier to supply a development restraining potential and an absolute value smaller than a target charging potential to the photoconductor while the reverse development voltage is supplied.

Abstract: An image forming apparatus includes: an image carrier; a developing housing that accommodates a developer for developing an electrostatic latent image into a developer image; a developer carrier, which carries the developer in the developing housing, and which supplies the developer to the image carrier; a developing bias supply part that supplies a developing bias to the developer carrier; a remaining quantity calculation part that calculates a remaining quantity of the developer in the developing housing; a deterioration grade storage part that stores a relationship between the remaining quantity of the developer in the developing housing and a deterioration degree of the developer caused by the developing operation; and a developing bias setting part that sets a value of the developing bias in accordance with the remaining quantity calculated by the remaining quantity calculation part and the relationship stored in the deterioration grade storage part.

Abstract: An image forming apparatus including: a photosensitive member; a conveying member; an exposure head; a developing unit; an image forming unit; a concentration sensor having a first detection width in a conveyance direction and a second detection width in an axial direction of the photosensitive member; and a control unit, wherein the control unit controls the exposure head and the image forming unit to form a first image for correction, which includes a straight line part extending in the axial direction of the photosensitive member and having a length equal to or larger than the second detection width of the concentration sensor, on the conveying member, and wherein the control unit corrects a developing bias to be applied to the developing unit based on a detection result of the first image for correction by the concentration sensor.

Abstract: An image forming apparatus is provided with a high-voltage substrate, a motor and a DC power source. The high-voltage substrate has a developing positive bias circuit and a developing reverse bias circuit which are connected to each other in parallel, in which the developing positive bias voltage is combined with developing reverse bias voltage to generate developing bias voltage. The high-voltage substrate includes a interruption switch for interrupting a reverse current from the motor to the developing reverse bias circuit in a case where an interlock switch is turned off at the time of emergency stop, in which, when the reverse current is interrupted by the interruption switch, electric power that is accumulated in the capacitor is supplied to the developing positive bias circuit to apply the developing positive bias voltage as the developing bias voltage to the developing roller for a given length of time.

Abstract: An image forming apparatus may include a sensor which detects a density of a patch image formed on an image carrier; an image quality control section which controls an image forming condition based on a detection value of the sensor; and a judging section which judges if the detection value has a tendency of increasing or decreasing, or not, wherein, the image quality control section compensates the image forming condition with a first compensating amount in case when the detection value does not have the tendency of increasing nor decreasing, and compensates the image forming condition with a second compensating amount of which absolute value is larger than an absolute value of the first compensating amount corresponding to the second compensating amount, in case when the detection value has the tendency of increasing or decreasing.

Abstract: In an image forming apparatus, a processor generates a first density variation data based on the surface potential of the pattern in relation to the rotational position of the image bearer and a second density variation data based on the first density variation data and the density of the toner pattern, stores the first density variation data and the second density variation data in a memory, makes a pattern in a predetermined timing, decides whether the first density variation data is changed or not, change the first density variation data based on the decision, controls the toner image forming condition of the toner image forming device based on the first density variation data and the second density variation data.

Abstract: An image forming apparatus includes an image carrier; a developing device; a transfer device; and a fixing device. An electrostatic latent image formed on the image carrier is rendered visible as a toner image by depositing the toner by the developing device, and the toner image is transferred by the transfer device and fixed onto a recording medium by the fixing device and output. The apparatus further includes a density fluctuation meter including a rotary position detector, a density fluctuation detector, and a density fluctuation storage; a density fluctuation extractor unit including a first extractor, a second extractor, and a density fluctuation storage; and a control table generator unit including a control table generator and a control table storage, so that based on the control table stored in the control table storage, the voltage to be applied to the developing device is controlled and the toner image is output.

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: 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: A color electrophotographic image forming apparatus, in which a plurality of cartridges each including an electrophotographic photosensitive drum are detachably mountable to a main assembly of the apparatus, includes an exposure device for forming an electrostatic latent image on the drum; a cartridge supporting member capable of demountably supporting the cartridges and movable between an inside position and an outside position; a driving device for driving the drum; an intermediary transfer belt onto which an image provided by developing the electrostatic latent image formed on the drum is transferred; and a controller for controlling execution of image formation in response to print jobs received by the apparatus. The controller causes the exposure device to expose the drum to light after completion of a last print job, and the controller stops drive of the drum by the driving device in a state that the exposed area is opposed to the intermediary transfer belt.

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: 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 bearing member; a development device that includes a developer bearing member in a development position opposite to the image bearing member to develop an electrostatic latent image formed on the image bearing member, the developer bearing member bearing and conveying a developer; a bias applying portion that applies a development bias to the developer bearing member; a recording-material sensing portion that senses a type of a recording material to which a toner image developed by the development device is transferred; and a controller that controls the bias applying portion to apply the development bias that degrades a development characteristic when the recording material has low smoothness, compared to high smoothness, from a sensing result of the recording-material sensing portion.

Abstract: An image forming apparatus includes an image carrier, a charging device to be applied with a charging voltage, an exposure device, a developer carrier to be applied with a development voltage, a developer supplying member to be applied with a supply voltage, a developer regulation member to be applied with a regulation voltage, and a voltage controller. The developer carrier has thereon a developer having a charge amount Q/M. The charge amount Q/M satisfies 25 [?C/g]?|Q/M|?40 [?C/g]. The image carrier has a surface potential Vopc, the development voltage is expressed as Vdb, and the developer carrier has a developer layer potential Vtnr thereon. The developer layer potential Vtnr relative to a difference between the surface potential Vopc and the development voltage Vdb is expressed by a ratio ?. The ratio ? satisfies 0.1???0.2.

Abstract: An image forming apparatus having; a latent image support member; a latent image forming unit for forming an electrostatic latent image on the latent image support member; a developer support member for supplying toner to the latent image support member to develop the electrostatic latent image; a voltage applying device for applying a developing bias, which is a superimposed voltage of a DC voltage and an AC voltage, to the developer support member; a first selecting device for selecting a screen ruling; and a second selecting device for selecting a frequency of the AC voltage. The second selecting device selects a first frequency when the first selecting device selects a first screen ruling, and selects a second frequency lower than the first frequency when the first selecting device selects a second screen ruling higher than the first screen ruling.

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 having; an electrostatic latent image support member; an electrostatic latent image forming section; a developer support member; a first voltage applying device for applying a developing bias voltage that is a superimposed voltage of a first DC voltage and a first AC voltage to the developer support member; and a controller for controlling the first voltage applying device. The first voltage applying device is controlled to stop an output of the first AC voltage at a first frequency, to change the first DC voltage outputted therefrom from a first voltage value to a second voltage value and to start an output of the first AC voltage at a second frequency, in this order. The controller selects a screen ruling for each page in accordance with image data and determines the output from the first voltage applying device in accordance with the selected screen ruling.

Abstract: There is provided an image forming apparatus in which a correction value is acquired from a storage device provided in a coloring agent cartridge mounted in the image forming apparatus, it is determined whether the acquired correction value is within a specified numerical range, and when it is determined that the acquired correction value is not within the specified numerical range, a control parameter of a specified process relevant to an image forming operation is corrected based on a specified correction value previously set to correct the control parameter of the specified process performed by the image forming apparatus.

Abstract: An image forming apparatus includes a separating unit for performing a stripping operation of forcibly returning toner particles carried on a toner bearing member to a developer bearing member, a sheet size discriminator for discriminating whether a sheet is a standard sized sheet or a long sheet, a determiner for determining whether or not there is any blank area of a predetermined length or longer in the sub scanning direction, where no toner image is to be substantially transferred, for each long sheet, and a controller for controlling the stripping operation. The controller causes the separating unit to perform the stripping operation at a developing timing of an electrostatic latent image corresponding to the blank area to be formed on the image bearing member when the sheet is a long sheet and when the blank area of the predetermined length or longer is present.

Abstract: An image forming method, includes a charging step of charging an image carrier; an image writing step of writing image data onto the image carrier; a developing step of developing a latent image area written by the image writing step on the image carrier; a transferring step of transferring a toner image developed by the developing step to a transferring member; an image writing position adjusting step of detecting a position of the image carrier where the image is written in a case where designated conditions are satisfied, and of adjusting an image writing position; and a voltage output control step of controlling voltages applied for charging, developing, and transferring in the charging step, the developing step, and the transferring step, respectively.

Abstract: The image forming apparatus includes a photosensitive drum capable of bearing an electrostatic image, a development device having a developing sleeve capable of bearing a developer and a developer container capable of storing a magnetic toner, and a CPU controlling operation to discharge a developer having polarity opposite to a normally charged polarity to the photosensitive drum by enlarging a restoration electric field to force the developer having a normally charged polarity from the photosensitive drum to the development sleeve during image forming is not performed compared to that during normal image forming is performed, based on a weighted value (p×K) on an edge portion pixel number p of an edge portion of an output image.

Abstract: An image forming apparatus includes an image supporting member; a developer supporting member for attaching developer to a static latent image formed on a surface of the image supporting member; a developer layer forming member for forming a developer layer on the developer supporting member; a developer supply member for supplying developer to the developer supporting member; a developer supporting member voltage applying unit for applying a voltage to the developer supporting member; a developer supplying member voltage applying unit for applying a voltage to the developer supplying member; and a reset operation processing unit for setting a reset mode over a specific period of time, so that a bias difference in the reset mode between the voltage applied with the developer supporting member voltage applying unit and the voltage applied with the developer supplying member voltage applying unit becomes smaller than that in a printing mode.

Abstract: An image forming apparatus includes a magnetic roller voltage applier for a magnetic roller, a developing roller voltage applier for a developing roller and a controller for controlling the appliers. The controller controls the magnetic roller voltage applier to apply, to the magnetic roller, a first voltage for forcibly conveying a thin layer of toner held on the developing roller toward the magnetic roller for a first period required for one turn of the developing roller, and controls the developing roller voltage applier to apply, to the developing roller, a second voltage for causing toner on the developing roller to fly onto the image carrier for a second period when at least the forcible consumption electrostatic latent image faces a facing portion between the developing roller and the magnetic roller. At least parts of the first period and the second period are overlapped with each other.

Abstract: Provided are a development apparatus and an image forming apparatus which, in a hybrid development apparatus provided with a plurality of toner carriers, a toner supply capability to supply toner to each toner carrier is controlled independent of development electric fields between the toner carriers and an image carrier, whereby each toner carrier is allowed to exhibit a desired development capability, and even in the case of high speed development, a high quality image is provided. The phases, the frequencies, and/or the duty ratios of the alternating current components of the voltages applied to the plurality of the toner carriers are made to be different, whereby the toner supply amount for each toner carrier from the developer carrier is controlled independently of the development electric fields between the toner carriers and the image carrier.

Abstract: An electronic development compensation method which is broadly applicable to SCMB development includes controlling image banding by actively correcting for mechanical development errors by modulating DC bias to a magnetic brush.

Abstract: An image forming apparatus includes a rotatable image bearing member; a developing device, including a developer carrying member and developing bias application means for applying a developing bias for developing a developer image; a rotatable intermediary transfer member; a primary transfer member for forming a primary transfer nip and for transferring the developer image from the image bearing member onto the intermediary transfer member; a secondary transfer member for secondary-transferring the developer image from the intermediary transfer member onto a recording material; wherein an area of the image bearing member includes a first area at least containing an area located in primary transfer nip at a time when a speed of the intermediary transfer member is temporarily decreased and includes a second area located in the primary transfer nip when there is no temporary change in speed; and a control device for controlling a developing bias.

Abstract: An image forming apparatus includes a photosensitive member, having a capacitance per unit area of 1.7×10?6 (F/m2) or larger, an exposure device, which exposes the photosensitive member in order to form thereon an electrostatic image according to image information, a developing device, which develops the electrostatic image with a toner to form a toner image on the photosensitive member, and a transfer device, which transfers the toner image onto a recording material. In forming a solid toner image on the recording material, the exposure device is capable of forming electrostatic images of different potential levels on the photosensitive member, thereby forming toner images of different toner heights on the photosensitive member.

Abstract: An image forming apparatus includes a photosensitive drum on which an electrostatic latent image is formed, a developing device that develops the electrostatic latent image on the drum using toner, a temperature sensor that detects toner temperature in the developing device, an optical sensor that detects the density of a patch image formed on the drum, a controller that controls the amount of the toner supplied to the developing device based on the detection result of the density of the patch image, and a setting portion that sets an potential difference between the electric potential of an image portion at the time of forming the patch image and a DC bias applied to the developing device. The setting portion sets the electric potential difference so as to be increased according to an increase in the toner temperature based on the detection result.

Abstract: An image forming apparatus with a correction function for correcting density of an image, including: an image bearing member configured to convey the image in a first direction; and a controller configured to perform a bias correction and a ? correction for the density, wherein the controller includes: a test patch generator configured to generate on the image bearing member a test patch including a first test patch and a second test patch; a first density sensor configured to detect density of the first test patch; a second density sensor configured to detect density of the second test patch; a selector configured to select one of a first detection signal from the first density sensor and a second detection signal from the second density sensor as a bias-correction detection signal and another detection signal as a ?-correction detection signal.

Abstract: An image forming apparatus includes a charging device to electrically charge a photosensitive member, an exposure unit to expose the charged photosensitive member to light, a development device to develop, with a developer, a latent image formed on the photosensitive member by the exposure unit, and a development bias voltage generating circuit to apply a development bias voltage to the development device. The development bias voltage generating circuit includes a transformer, a capacitor connected to one end of the transformer, first-fourth switching elements, a power source to supply a voltage to the first and third switching elements, and a control unit to control an on and off action of the first to fourth switching elements and independently control the voltages applied by the power source to the first and third switching elements.