Abstract: An image forming apparatus and a method of driving the same are provided in which, if a driving environment is determined to be a low temperature environment, a driving load of an image forming unit is decreased by repeating driving and stopping a driving motor under a high load driving condition to generate a torque higher than a torque generated under a normal warm-up driving condition; and a warm-up operation is performed by driving the driving motor under the normal warm-up driving condition.

Abstract: An image forming apparatus includes: a first photosensitive drum for a monochrome printing mode; second and third photosensitive drums for a color printing mode; a moving unit moving a medium from the first photosensitive drum via the second photosensitive drum to the third photosensitive drum; charger devices for charging the photosensitive drums; transfer devices for transferring developer images on the photosensitive drums to the medium; and a control unit configured to control charging biases of the charger devices and transfer biases of the transfer devices. The control unit executes, in the monochrome printing mode, an energy saving control in which an absolute value of a charging bias applied to the charger device for the third photosensitive drum is smaller than an absolute value of a charging bias applied to the charger device corresponding to the second photosensitive drum.

Abstract: A method for making a tone consistency calibration timing decision includes measuring, with sensors and in conjunction with a first tone consistency calibration, a first state of a printer. A second state of the printer is also measured. A machine learning calibration module implemented by a computer processor determines if changes between the first state and second state justify a tone consistency calibration. If the changes between the first state and second state justify a second tone consistency calibration, then the second tone consistency calibration is performed.

Abstract: A printing apparatus/method includes at least one processor, at least one printing engine, and at least one graphic user interface all operatively (directly or indirectly) connected to each other. The graphic user interface has at least one display and at least one user input device. The display provides at least one menu having at least one user selectable parameter of the printing engine. The display provides at least one linear scale bar representing a range of values to which the selectable parameter can be set. The display provides at least two different graphic icons along the linear scale. The graphic icons conceptually represent different performance characteristics that the printing apparatus will have when the selectable parameter is set to different values along the range of values represented on the linear scale. The display can also provide numerical performance values adjacent each of the different graphic icons.

Abstract: An image forming device has a heating member, a thermal detecting unit, and a control unit. The heating member is positioned at an ambient temperature and heated by a heat source. The heating member fixes a developed image to a recording sheet. The thermal detecting unit is provided separately from the heating member. The thermal detecting unit detects a first temperature. The control unit uses a function to calculate a second temperature of the heating member on the basis of the detected first temperature. The control unit controls the heat source on the basis of the second temperature. The function has a rate of change that increases with decreasing the ambient temperature.

Abstract: A moisture sensor for detecting moisture content of an object includes a light source to emit light having an infrared wavelength that is absorbed by water; an optical system to receive the light from the light source and output linearly polarized light having a first polarization direction in a direction toward the object, and to receive light scattered from the object and output linearly polarized light having a second polarization direction perpendicular to the first polarization direction in another direction other than the direction toward the object; and a photodetector to receive the linearly polarized light having the second polarization direction output from the optical system.

Abstract: A transfer device includes an intermediate transfer belt, a driving roller, an environment sensor, a resistance detecting sensor, and a speed ratio adjusting section. The toner images are transferred from the plurality of image carriers onto a surface of the intermediate transfer belt in a superimposed manner. The driving roller circumferentially and rotationally drives the intermediate transfer belt. The environment sensor detects a temperature or a humidity around the intermediate transfer belt. The resistance detecting section detects a change in a resistance value of the intermediate transfer belt. The speed ratio adjusting section controls a rotation speed of the driving roller according to results of detection by the environment sensor and the resistance detecting section, thereby adjusting a speed ratio Vb/Vd between a circumferential rotating speed Vb of the intermediate transfer belt and a rotation speed Vd of the image carrier.

Abstract: An image forming apparatus includes an image carrier to carry a toner image; a driving unit to drive the image carrier to rotate; a transfer unit to transfer the toner image at a transfer position; a cleaner at a cleaning position to remove toner remaining on the image carrier after transfer; an obtaining unit to obtain information indicating a likelihood of the remaining toner adhering to the image carrier; a judging unit to judge whether or not the likelihood is equal to or lower than a predetermined value; and a controller to control the driving unit (i) to stop driving the image carrier before a rear end of an area of the image carrier on which the toner remains reaches the cleaning position, when the judging unit judges affirmatively, and, (ii) to stop driving the image carrier after the cleaner removes the remaining toner, when the judging unit judges negatively.

Abstract: A group of printing conditions, which have at least one condition item in common except for environmental condition items concerning a temperature and humidity environment for printing, is selected from among a plurality of printing conditions. A list image, which represents a line-up of visible information concerning the temperature and humidity environment depending on the environmental condition items, and which is included in the printing conditions of the selected group, is generated and displayed.

Abstract: There is provided a fixing device for thermally fixing a developing agent image to a sheet. The fixing device includes a tubular flexible member, a heater, a nip member, a reflection plate, a backup member, a stay and a temperature sensor. The flexible member has an inner peripheral surface defining an internal space. The heater is disposed in the internal space and is configured to generate a radiant heat. The nip member is disposed in the internal space, the inner peripheral surface being in sliding contact with the nip member. The reflection plate is configured to reflect the radiant heat from the heater toward the nip member, the reflection plate having an outer profile. The backup member is configured to provide a nip region in cooperation with the nip member for nipping the flexible member between the backup member and the nip member.

Abstract: An image forming apparatus includes an image carrier, a charging member, a transferring member, a first voltage applying part, a current measuring part, a fan, a cleaning member and a controlling part. The controlling part carries out an aging operation rotating the image carrier and bringing the cleaning member in sliding contact with the image carrier before forming an image. The controlling part lengthens a running time of the aging operation in a case where a current value measured by the current measuring part is equal to or less than a first threshold value when the fan blows an outside air to the image carrier and the first voltage applying part applies voltage to one of the charging member and transferring member, in comparison with another case where the current value measured by the current measuring part exceeds the first threshold value.

Abstract: An image forming apparatus includes an image carrier; a latent-image forming unit configured to form a latent image on the image carrier; a developing unit configured to develop the latent image on the image carrier with a developer applied onto a developer carrier; a temperature detector configured to detect an internal temperature or an ambient temperature of the developing unit, the internal temperature and ambient temperature varying depending on a temperature of the developer carrier; and a control unit configured to control restriction on number of pages on which image formation is allowed to be performed continuously and cancellation of the restriction, based on the temperature detected by the temperature detector.

Abstract: In an image forming apparatus, a fixing condition such as a target control temperature of a heater is changed depending on whether a first resistance heating element and a second resistance heating element of the heater are connected in series or in parallel such that a similar fixing performance is achieved regardless of whether the first resistance heating element and the second resistance heating element are connected in series or in parallel.

Abstract: An image forming apparatus includes an image carrier, a transferer to apply a constant-current controlled bias to a transfer medium to form a transfer electric field, a constant-current source configured to apply an electrical current to the transferer, an electrical characteristic detector, an environment detector, a first corrector, a second corrector, and a third corrector. The electrical characteristic detector detects an electrical characteristic value corresponding to a resistance in a current path from the constant-current source to the transferer. The environment detector detects an environmental condition inside the image forming apparatus. The first corrector corrects the electrical current based on the electrical characteristic detection and a predetermined threshold. The second corrector corrects the electrical current based on the environment detection. The third corrector sets the threshold based on the environment detection.

Abstract: An image forming apparatus includes: an image bearing member; a development device; a speed varying unit that can vary a speed of a developer bearing member; a sensing portion that senses an environmental temperature around the development device; and a controller that can perform a mode in which, compared with a period which an image forming region of the image bearing member passes through the developing region, the rotation speed of the developer bearing member slows down a period which a non-image forming region of the image bearing member passes through the developing region, wherein based on sensing result of the sensing portion, the controller performs the mode when the environmental temperature is higher than a predetermined value, and the controller does not perform the mode when the environmental temperature is lower than the predetermined value.

Abstract: A lubricant supply device including a solid lubricant, a lubricant supply roller, a detector, and a varying device is provided. The lubricant supply roller is adapted to supply the lubricant to a toner image bearing member and is rotatable in a predetermined direction while slidably contacting both the solid lubricant and the toner image bearing member. The detector is adapted to detect an absolute humidity around the lubricant supply device. The varying device is adapted to vary an amount of the lubricant to be supplied to the toner image bearing member based on the absolute humidity detected by the detector.

Abstract: An image forming apparatus including an image bearing member; a developing device for developing with toner an electrostatic latent image formed on the image bearing member; a humidity sensor for providing information on ambient humidity of said image forming apparatus; and a controller for controlling a parameter on a density of an image to be formed on a recording material on the basis of pieces of the information provided by the humidity sensor at different times.

Abstract: An image forming apparatus that prevents transfer defects such as the occurrence of white spots includes a photoreceptor drum, a transfer roller, a transfer bias application circuit that applies a transfer bias to the transfer roller, a static elimination needle that eliminates static of a recording paper, a static elimination bias application circuit that applies a static elimination bias to the static elimination needle, and a printer controller. The printer controller controls the static elimination bias application circuit so that a potential difference between the static elimination needle and the recording paper during the period from when a front end region of the recording paper passes by the static elimination needle until when a front end of the recording paper comes into contact with a conveyance guide becomes smaller than the potential difference during the period that the front end region of the recording paper passes by the static elimination needle.

Abstract: An image forming apparatus includes an image bearing member for carrying an electrostatic latent image; a developing device, containing a developer including a toner and a carrier, for developing the electrostatic latent image carried on the image bearing member into a toner image with the developer; a supplying device for supplying the toner to the developing device; a first detecting portion for detecting information on a temperature of the developing device; a second detecting portion for detecting information on a temperature of the supplying device; and a correcting portion for correcting, when detection results of the first and second detecting portions are different from each other, an image forming condition with increase of a supply amount of the supplying device.

Abstract: A fixing device includes a fuser member, a pressure member, a positioning mechanism, an operational thermometer, an environmental sensor, and a controller. The fuser member is subjected to heating. The pressure member is opposite the fuser member. The fuser member and the pressure member press against each other to form a fixing nip therebetween through which a recording medium is passed. The positioning mechanism is coupled with the pressure member to move the pressure member into and away from contact with the fuser member. The operational thermometer adjoins the pressure member to detect an operational temperature at a surface of the pressure member. The environmental sensor is disposed in the image forming apparatus to detect an environmental condition. The controller is connected to the operational thermometer and the environmental sensor to control the positioning mechanism to adjust spacing between the fuser member and the pressure member.

Abstract: An image forming apparatus includes a photoconductor; an intermediate transfer belt to which a toner image formed on the photoconductor is transferred, the intermediate transfer belt holding the toner image transferred thereto; a first transfer roller that nips the intermediate transfer belt between the first transfer roller and the photoconductor to transfer the toner image formed on the photoconductor to the intermediate transfer belt; a second transfer roller that transfers the toner image held by the intermediate transfer belt to a recording medium; a detection unit that detects an environmental condition; and a separation position changing unit that changes a first separation position in accordance with the environmental condition, the first separation position being a position at which the intermediate transfer belt becomes separated from the first transfer roller.

Abstract: An image forming apparatus includes an image carrier, a charging member, a voltage applying part, a current measuring part and a controlling part. The image carrier carries a toner image. The charging member electrically charges the image carrier. The voltage applying part applies voltage to the charging member. The current measuring part measures current flowing into the charging member. The controlling part controls applied voltage of the voltage applying part. The controlling part decides, when a predetermined voltage is applied to the charging member for a predetermined time by the voltage applying part, if an increase quantity of the current measured by the current measuring part exceeds a predetermined threshold value, that at least one of the image carrier and the charging member is in an abnormal state.

Abstract: An image forming apparatus which makes it possible to save energy during the operation of a temperature rise control mode, and is capable of realizing energy saving without degrading performance by making the image forming apparatus ready for printing when returning from the temperature rise control mode. A temperature sensor detects internal temperature of the image forming apparatus. When the internal temperature of the image forming apparatus has reached a temperature at which the apparatus should shift to the temperature rise control mode during execution of printing, the printing operation is stopped. In stopping the printing operation, the image forming apparatus is shifted to an energy saving mode.

Abstract: An image forming apparatus including a setting memory storing multiple voltage settings; two or more voltage applying members each contacting a voltage applied member at respective contact positions close to each other, which are simultaneously being applied with respective voltages selected from the voltage settings; two or more current detectors each detecting a current flowing in the respective contact positions; and a setting changer performing a setting changing processing in which the voltage applied to one of the voltage applying members is changed based on the current detected by the corresponding current detector while a predetermined voltage is applied to the other voltage applying members, so that an optimum current flows in the corresponding contact position.

Abstract: A transfer device includes a transfer device, a facing member, and a prepressing member. The transfer member transfers a toner image, which is carried on an intermediate transfer member, to a recording medium. The facing member is disposed so as to be in pressed contact with the transfer member with the intermediate transfer member therebetween. The prepressing member is disposed so as to be in pressed contact with the transfer member with the intermediate transfer member therebetween at a position that is upstream of a contact section in which the facing member is in pressed contact with the transfer member and that is immediately behind a position at which the toner image starts to come into contact with the recording medium. A pressure applied by the prepressing member is lower than a pressure with which the facing member is in pressed contact with the transfer member.

Abstract: A rotation amount detecting device for a rotation body includes: a first rotation body having a first surface; a second rotation body having a second surface formed of a material different from that of the first surface and contacting the first surface, and rotating with rotation of the first rotation body; a first support member rotatably supporting the first rotation body at a first position and supporting thereof to be swingable around a first axis at a position different from the first position; a second support member rotatably supporting the second rotation body at a second position and supporting thereof to be swingable around a second axis provided at a position different from the second position, the second axis being the first axis or an axis in the first support member other than the first axis; and a detector that detects a rotation amount of the second rotation body.

Abstract: An image forming apparatus includes an image carrier, a transfer member and a cleaning member. The image forming apparatus: determines whether the electric resistance of a recording medium is low or high; applies a first transfer bias to the transfer member if the electric resistance is low; applies a second transfer bias to the transfer member if the electric resistance is high; applies a first cleaning bias to the cleaning member if the electric resistance is low; and applies a second cleaning bias to the cleaning member so that a potential difference between a portion of a surface of the image carrier against which the cleaning member is rubbed and the cleaning member becomes smaller than that in a case of applying the first cleaning bias if the electric resistance is high.

Abstract: An image forming apparatus includes: an endless belt having an outer circumferential surface for conveying a recording sheet; a photosensitive member provided to face the outer circumferential surface of the endless belt; a cleaning member provided to face the outer circumferential surface of the endless belt and configured to clean the outer circumferential surface of the endless belt; and a control device configured to control a cleaning bias to be applied to the cleaning member such that while a portion of the outer circumferential surface of the endless belt, which has contacted the recording sheet since being cleaned by the cleaning member, faces the cleaning member, a second bias, which is larger than a first bias having been applied to the cleaning member before the corresponding portion faces the cleaning member, is applied to the cleaning member.

Abstract: An image forming apparatus includes a power source to output a voltage having an alternating waveform to transfer a toner image from an image bearing member to a recording medium. A time-averaged value (Vave) of the voltage has a polarity in a transfer direction, in which the toner image is transferred from the image bearing member to the recording medium, and an absolute value of the time-averaged value is greater than a midpoint value (Voff) of the voltage intermediate between a maximum value and a minimum value of the voltage. As a roughness of the recording medium increases, a duty ratio (Duty) expressed by A/(A+B) is reduced, where A is an area of the waveform of the voltage in a return direction opposite the transfer direction relative to the midpoint value in one cycle and B is an area in the transfer direction relative to the midpoint value.

Abstract: An image forming apparatus capable of executing continuous image forming operation forming images on more than one page includes a temperature detector that detects internal or surrounding temperature of a developing device correspondingly changing to temperature of a developer bearer. A temperature information acquiring device acquires information of ambient temperature outside of the image forming apparatus. A controller switches a current operation mode to an intermittent image forming operation mode intermittently including a braking time period not to allow image formation and cancels the intermittent image forming operation mode in accordance with detection result of the temperature detector. The intermittent image forming operation mode allowed to continuously form images only on a prescribed limited number of sheets. The controller varies the braking time period in accordance with the ambient temperature detected by the temperature information acquiring device.

Abstract: An image forming apparatus includes an imaging unit, a fixing unit, a first thermometer, and a controller. The imaging unit forms a toner image on a recording medium conveyed along a media conveyance path. The fixing device is disposed downstream from the imaging unit along the media conveyance path to fix the toner image in place on the recording medium. The fixing device includes a fuser roller, a heat roller, an endless, fuser belt, and a pressure roller. The fuser roller has a cylindrical core of metal. The pressure roller presses against the fuser roller via the fuser belt to form a fixing nip therebetween. The first thermometer detects a first temperature at the cylindrical core of the fuser roller. The controller controls conveyance of the recording medium through the fixing nip according to the first temperature.

Abstract: An image forming apparatus includes a photosensitive member, a developing device for developing with toner an electrostatic image formed on the photosensitive member, a temperature/humidity sensor, and a storing portion for storing environmental information. In addition, a controller controls an image forming condition so that when a second temperature/humidity environment, measured by the temperature/humidity sensor, is different from a first temperature/humidity environment and when the image forming condition is changed to a second image forming condition different from a first image forming condition, a change amount of the image forming condition when the developing device is driven before the image forming condition is changed is larger than a change amount of the image forming condition when the developing device is not driven before the image forming condition is changed.

Abstract: An image forming apparatus includes a measurement unit configured to irradiate a measurement image with light, and measure the light reflected from the measurement image, a white reference plate disposed in a position opposite to the measurement unit, a correction unit configured to correct a measurement result of the measurement image, based on a measurement result of the white reference plate acquired by the measurement unit, and a temperature detection unit configured to detect temperature in a vicinity of the measurement unit, wherein the correction unit corrects, in a case where a difference between a temperature detected by the temperature detection unit and a temperature shown when previously measuring the white reference plate is less than a predetermined value, a measurement result of the measurement image using a previous measurement result of the white reference plate without measuring the white reference plate with the measurement unit.

Abstract: An image forming apparatus includes an image carrying member, a developer carrying member configured to carry developer to be supplied to the image carrying member, a transfer member configured to transfer a developer image formed on the image carrying member to a sheet passing between the image carrying member and the transfer member, a detector configured to detect a temperature, and a control device. The control device is configured to change, in response to a sheet interval, a developing bias to the applied to the developer carrying member from a first developing bias to a second developing bias at a changing rate based on a temperature detected by the detector, the changing rate being an amount of change in the developing bias per unit time based on the temperature.

Abstract: An image forming apparatus includes an image carrier, a developing part, a storing part and an adjusting part. The image carrier includes a surface. An electrostatic latent image formed on the surface is developed by a toner, thereby forming a toner image on the surface. The developing part contains the toner supplied from a toner cartridge and supplies the toner to the image carrier. The storing part stores information relating to a replacement rate when a first toner in the developing part is replaced by a second toner, in a case where kinds of the first toner contained in the developing part and the second toner being supplied from the toner cartridge are different. The adjusting part adjusts density of the toner image on the basis of the replacement rate when a toner cartridge containing the first toner is replaced by another toner cartridge containing the second toner.

Abstract: An image forming apparatus having a temperature detection unit that detects a current interior temperature based on a detection signal from a temperature sensor. A temperature change detection unit calculates a difference between the current interior temperature and an interior temperature detected in a last color misregistration correction processing as a temperature change amount. When the temperature change amount is equal to or higher than a threshold, a determination unit determines that a color misregistration correction operation needs to be executed. A mode setting unit determines whether a monochrome printing processing is currently carried out.

Abstract: A fixing device includes a fixing belt; a pressing rotary body disposed outside a loop formed by the fixing belt; a nip formation pad disposed inside the loop formed by the fixing belt and pressed against the pressing rotary body via the fixing belt to form a fixing nip between the pressing rotary body and the fixing belt through which a recording medium bearing a toner image is conveyed. The nip formation pad includes a protrusion disposed downstream from the fixing nip in a conveyance direction of the recording medium and protruding toward the pressing rotary body without contacting the pressing rotary body. The fixing device further includes a pressing rotary body mover to contact and move the pressing rotary body bidirectionally in the conveyance direction of the recording medium to move the fixing nip toward and away from the protrusion.

Abstract: An image forming apparatus is provided. The image forming apparatus includes a photosensitive member, a developing roller which carries developer and contacts the photosensitive member, and a control device which is configured to apply, to the developing roller, a developing bias having a direct current component and an alternating current component overlapped with each other so as to supply developer from the developing roller to the photosensitive member. The control device is configured to execute either one of a first mode in which an amplitude of the alternating current component of the developing bias is set with a first set value and a second mode in which the amplitude of the alternating current component of the developing bias is set with a second set value larger than the first set value, based on whether or not a temperature of the developing roller is a first predetermined value or larger.

Abstract: An image forming apparatus includes an image bearing member on which a developer image is formed, a developer bearing member configured to develop a surface of the image bearing member, and a cleaning member configured to clean a residual developer remaining on the surface of the image bearing member, wherein, when an image forming operation is interrupted, the image forming apparatus is capable of performing a recovery operation before resuming the image forming operation, and wherein the image forming apparatus is capable of, during the recovery operation, a potential difference between a potential applied to the developer bearing member and a surface potential of a non-image area within the surface of the image bearing member greater than that during the image forming operation according to a predetermined value such that the developer on the image bearing member is moved to the developer bearing member.

Abstract: An image forming apparatus includes an image forming unit configured to form an image under a control condition and including developing device; a toner cartridge configured to supply toner to the developing device; a measuring device configured to acquire measurement data; a first memory which is provided for the toner cartridge and includes a data reference destination for obtaining the control condition and a correction value of the control condition for standard data or a plurality of control data corresponding to the measurement data; a second memory configured to store the measurement data, the standard data, one of the correction value and the control data, and the obtained control condition; and a processing mechanism configured to read the standard data and the correction value, or the measurement data and the control data and to obtain the control condition.

Abstract: An image forming apparatus includes a plurality of image forming units, an endless transfer belt, and a plurality of transfer rollers. Each image forming unit includes a photosensitive drum, a charging unit, a developing unit, and a static remover. The static remover emits charge-removing light to the circumferential surface of the photosensitive drum included in the image forming unit before a transfer to the circumferential surface is performed. The amount of pre-transfer charge-removing light emitted to the circumferential surface of a photosensitive drum by one static remover included in the plurality of image forming units is set to a value less than the amount of pre-transfer charge-removing light emitted to the circumferential surface of another photosensitive drum by another static remover located upstream of the one static remover in the movement direction of an intermediate transfer belt.

Abstract: According to one embodiment, an image forming apparatus includes a printing unit, a fixing device, a conveying roller, and a control unit. The printing unit is configured to form an image by transferring toner onto a sheet. The fixing device is configured to heat and fix the toner onto the sheet. The fixing device is disposed on the downstream side of the printing unit. The conveying roller is configured to convey the sheet from the fixing device. The conveying roller is disposed on the downstream side of the fixing device. The control unit is configured to control the sheet heated by the fixing device to pass through the conveying roller a plurality of times before the image is formed on the sheet by the printing unit.

Abstract: An image forming apparatus includes an intermediary transfer member having an elastic layer; a toner image forming portion for forming a toner image for an image to be carried on the intermediary transfer member; a transfer member, which presses the intermediary transfer member, for transferring the toner image for the image from the intermediary transfer member onto a recording material; a pressing mechanism capable of changing pressure applied from the transfer member to the intermediary transfer member; and a controller for controlling the toner image forming portion so that a length of the toner image for the image on the intermediary transfer member with respect to a rotational direction of the intermediary transfer member is decreased with an increase of the pressure.

Abstract: A fixing apparatus that fixes a toner image on a sheet includes each of fans configured to respectively cool areas adjacent to a longitudinal center and longitudinal both ends of a pressure roller, and in a case where fixing processing is performed on thin paper of a maximum width size, includes a first mode in which the fixing processing is started after the fan configured to cool the area adjacent to the longitudinal center of the pressure roller is actuated for a predetermined time and a second mode in which the fixing processing is started after the fan configured to cool the area adjacent to the longitudinal both ends of the pressure roller is actuated for a predetermined time.

Abstract: An image forming apparatus has an image carrier carrying an electrostatic latent image, a charging unit charging the surface of the image carrier, an exposure unit forming an electrostatic latent image by irradiating light onto the charged surface of the image carrier, a developing unit developing the electrostatic latent image formed on the surface of the image carrier using a developing material, and a transfer unit transferring a developer image onto a printing material. The apparatus has also an image correction unit correcting image data inputted to the exposure unit so as to compensate for deformation in the developer image originating in a form of the exposure unit, and a smoothing processing unit carrying out smoothing of an image by controlling the exposure unit so that dots of a size smaller than one pixel are filled with respect to a white image region of the corrected image data.

Abstract: An image forming apparatus includes a rotatable image bearing member for bearing a toner image; a transfer member constituting a transfer portion for transferring the toner image formed on the image bearing member onto a recording material; a voltage source for applying, to the transfer member, a voltage in the form of superimposed DC voltage and AC voltage; a controller for controlling the voltage source such that a duty ratio of the AC voltage is changed in accordance with a kind of the recording material; and an executing portion for executing an operation in an image forming mode in which the toner image is transferred from the image bearing member onto the recording material with the duty ratio controlled by the controller.

Abstract: An image forming apparatus includes a rotatable drum; a developing device for developing a latent image formed on the drum into a developer image; and a cleaning blade for removing developer remaining on the drum after the developer image is transferred from the drum onto a developer image receiving member. After image formation, a predetermined amount of strain of the cleaning blade is released and the drum is subsequently rotated. The drum is subsequently rotated in a direction identical to a rotation direction of the drum during image formation.

Abstract: An image forming apparatus includes: a photosensitive member that is configured to carry a developer image; a developing roller that is configured to supply developer to the photosensitive member; a transfer member that is configured to transfer the developer image carried on the photosensitive member to a transfer medium; and a control unit that is configured to execute a collection mode upon receiving a printing instruction for executing a printing operation but before initiating the printing operation, wherein the control unit in the collection mode is configured to: discharge the developer of one or more circumferences of the developing roller, which has been carried on the developing roller, to the photosensitive member; and collect the discharged developer by the developing roller.

Abstract: A bias power supply device includes: a temperature detecting unit; a control signal generation unit generating and outputting an output frequency setting signal for setting a frequency of an alternating current power in accordance with a repetition frequency and a resonance frequency signal being set at a lower or higher repetition frequency according to the measured temperature; a waveform signal generation circuit generating a waveform signal for pulse-width modulation having a time constant for rising set by capacity and resistance based on the resonance frequency signal; a modulation circuit generating a pulse-width-modulated modulation signal based on the waveform signal and the output frequency setting signal; a switching circuit driven by the modulation signal; and a transformer having a first winding and a second winding, and supplying an alternating current power with a repetition frequency of the output frequency setting signal to an external load connected to the second winding.

Abstract: An image forming apparatus for printing an image on a medium, including: a first image carrier; a second image carrier disposed downstream of the first image carrier in a traveling direction of the medium; a first charging member configured to charge the first image carrier; a second charging member configured to charge the second image carrier; and a control unit configured to execute a monochrome printing mode in which a monochromic image is formed on the medium using the first image carrier and the first charging member and a color printing mode in which a color image is formed on the medium using the second image carrier and the second charging member. In the monochrome printing mode, the control unit makes an absolute value of an electric surface potential of the second image carrier larger than an absolute value of an electric surface potential of the first image carrier.