In one example, a method is described that includes a processor detecting a voltage of a photoconductor layer (103) of a printing device, comparing the voltage of the photoconductor layer (103) to a threshold voltage, and applying a corrective voltage to a charging unit (110) or to a transfer member (104) when the voltage of the photoconductor layer (103) exceeds the threshold voltage.

An image forming apparatus includes a developing roller, a voltage applying part, a direct current correcting part and a correction switching part. The developing roller supplies a toner to an image carrier. The voltage applying part applies a superimposed voltage of an alternating current voltage and a direct current voltage to the developing roller. The direct current correcting part corrects the direct current voltage on the basis of variation of an alternating current flowing between the voltage applying part and the developing roller. The correction switching part switches the direct current voltage correcting part between an operating state and a non-operating state.

An image forming apparatus includes an image bearing member, a transfer member, a power source, a detection unit, and a fixing unit. The transfer member transfers a toner image to a transfer material from the image bearing member. The detection unit detects electric current flowing in the transfer member when the power source applies voltage to the transfer member. The fixing unit fixes a toner image to a transfer material by heat. The heat to the fixing unit is controlled where a subsequent. transfer material conveyance stops after the transfer material is discharged from the fixing unit, in a case where a second current value, detected when voltage is applied to the transfer member contacting the fixing unit and the transfer member, is greater than a first current value detected. when voltage is applied to the transfer member before the transfer material reaches the fixing unit.

A control unit of an image forming apparatus can perform a density correction mode to correct toner density, based on detection results of toner density of a plurality of reference images formed with density gradations changed sequentially in a plurality of steps, detects presence or absence of a change in the voltage in each density gradation, based on the toner density detection value detected in the density correction mode, and if the density gradation has a specific density gradation in which a change in the voltage is detected, it corrects the toner density of the specific density gradation, using the detection values of density gradations before and after the specific density gradation.

In an image forming apparatus including a transfer member, a control unit, and a feeding unit including a blowing unit which blows air to leading edge portions of recording materials contained in a container, the control unit sets a transfer voltage for the transfer member during image formation based on detection results by a reading unit when a region to which at least one density acquisition image is to be transferred in a recording material on which a chart is formed is passing through a transfer portion, detection results when a predetermined region closer to the leading edge side than the region to which a plurality of density acquisition images is to be transferred in a conveyance direction of the recording material on which a chart is formed is passing through the transfer portion, and information about densities of the plurality of density acquisition images.

An image forming apparatus includes an image carrying member, a charging device, a charging voltage power supply, an exposure device, a development device, a development voltage power supply, an intermediate transfer member, a primary transfer member, a secondary transfer member, a transfer voltage power supply and a control unit. The development device includes a developer carrying member which carries a developer containing a toner. The development voltage power supply applies, to the developer carrying member, a development voltage in which an alternating-current voltage is superimposed on a direct-current voltage. The transfer voltage power supply applies a transfer voltage to the primary transfer member and the secondary transfer member. The control unit performs a first image quality improvement mode in which the frequency of the alternating-current voltage of the development voltage and a primary transfer current flowing between the image carrying member and the primary transfer member are simultaneously changed.

An image forming apparatus includes a developing cartridge, a drum cartridge, a casing, a connector, and a controller. The drum cartridge includes a photosensitive drum, a drum cartridge memory, a charger, and a cleaner. The charger is configured to charge the photosensitive drum and including a wire and a grid electrode. The cleaner is configured to clean the wire. The connector is configured to be electrically connected to the drum cartridge memory. Information is writable to the drum memory through the connector. The detection circuit board is configured to detect a state of discharge of the charger. The controller is configured to perform: determining whether or not the state of discharge detected by the detection circuit board is abnormal; and writing, in the drum cartridge memory, information representing occurrence of the abnormal discharge through the connector in a case where occurrence of the abnormal discharge is determined.

An image forming apparatus includes an image bearing member, a brush, and a controller. The controller controls so that, in a case where, in a state where a recording material trailing edge in a conveyance direction is sandwiched at a transfer portion, an area of the image bearing member in the conveyance direction where the recording material is sandwiched in a direction perpendicular to the conveyance direction is a first area, and an area of the image bearing member in the conveyance direction where the recording material is not sandwiched is a second area, a first potential difference formed between a surface potential formed on the second area and a brush voltage, which is based on first information, when the second area reaches the brush and a second potential difference formed between the second area surface potential and the brush voltage, which is based on second information, are different.

An image forming apparatus includes a photosensitive member, a charging member, an exposing device, a developing device, a transfer member, a brush, a voltage applying portion, and a control portion controlling a surface potential of the photosensitive member at the brush contacting position. When a value of subtracting a value of the surface potential of the photosensitive member in the brush contacting position from a value of the brush voltage is defined as a contacting position potential difference, the control portion controls the surface potential of the photosensitive member in the brush contacting position so that the contacting position potential difference is changed from a first potential difference to a second potential difference in a predetermined direction which is either one of an increasing direction or a decreasing direction, and then the contacting position potential difference is changed from the second potential difference to a third potential difference in the predetermined direction.

An image forming apparatus includes a plurality of image bearers, an intermediate transferor, a plurality of primary transferors, a primary transfer power source, a primary transfer current detector, and processing circuitry. The primary transferors primarily transfer toner images of colors from the image bearers onto the intermediate transferor. The intermediate transferor secondarily transfers the toner images onto a transfer medium. The primary transfer power source applies voltage to the primary transferors. The primary transfer current detector detects a current flowing through the primary transferors when a specified voltage is applied to the primary transferors and is connected to only one primary transferor of one color among all the colors. The processing circuitry determines a primary transfer voltage based on a current value detected by the primary transfer current detector and determines a primary transfer voltage value of the primary transferors of all the colors based on the detected current value.