An imaging device includes a photoconductive drum charged by a charge roll and opposed by a transfer roll to transfer an image from the drum. The drum becomes biased to a negative voltage by setting charges of negative voltage on both the charge roll and transfer roll. A controller switches the bias of the transfer roll to a positive voltage from the negative voltage and a delta or difference in a charge of the drum is determined from before and after the switching. Based on the delta, the voltage on the charge roll is boosted by a boost voltage to improve the charge on the drum. In this way, deteriorating or defective charge rolls can be still used to charge the drum to a proper voltage for imaging. Techniques for determining the delta, the boost and the magnitude of voltage charges are further embodiments.

In an example, a method of controlling voltage applied to a print blanket within a printing device includes printing a print job. During the printing, a null cycle trigger is received. In response to the trigger, a print blanket bias voltage is reduced from a print bias level to a null bias level.

A feeding apparatus includes a feeding unit, an ion generating unit and a controller. The ion generating unit irradiates the sheet fed by the feeding unit with the ion. The controller acquires an information on the fed sheet and to controls the ion generating unit. The controller operates the ion generating unit in a case that the information of the sheet is a first information, and does not operate the ion generating unit in a case that the information of the sheet is a second information.

A cartridge includes a photosensitive member, a roller including a core metal shaft and a coating layer, roller supporting portions, and a regulating portion for regulating a position of the roller with respect to a longitudinal direction of the roller. The roller supporting portions are provided so as to support one end portion and an other end potion of the core metal shaft, respectively, with respect to a direction of a rotational axis of the roller. The roller is further provided with cylindrical holes disposed at respective ends of the core metal shaft with respect to the direction of the rotational axis and extending in the direction of the rotational axis with the rotational axis as a center. The roller is supported by the roller supporting portions at inner peripheral surfaces of the holes.

A charging device includes a first charging unit and a second charging unit. The first charging unit electrostatically charges a surface of an image bearing member that comes into contact with a medium onto which an image is to be ultimately transferred. The first charging unit is disposed in correspondence with an entire region of the image bearing member in a first scanning direction. The second charging unit is disposed in an overlapping region where a non-passing region of a small-width medium and a passing region of a maximum-usable-width medium overlap when viewed in the first scanning direction. The small-width medium has a width smaller than a maximum usable width of the maximum-usable-width medium. The second charging unit electrostatically charges the overlapping region.

An image forming apparatus includes: a first photoconductor and a second photoconductor; an image carrier onto which a toner image formed on the first photoconductor and a toner image formed on the second photoconductor are transferred; and a controller that, when the toner image formed on the first photoconductor is transferred onto the image carrier, rotates the second photoconductor while keeping the second photoconductor spaced apart from the image carrier.

An image forming apparatus including: a charging member configured to charge a photosensitive member at a charging portion by a charging voltage in which an alternate-current voltage is superimposed on a direct-current voltage; a transfer member configured to transfer a toner image formed on the photosensitive member to a recording material at a transfer portion; and a controller configured to control the charging voltage, a predetermined area of the photosensitive member passing through the transfer portion during a trailing edge of the recording material passing through the transfer portion, wherein the controller controls a value of a peak-to-peak voltage of the alternate-current voltage when the predetermined area passes through the charging portion to be larger than a value of a peak-to-peak voltage when an area that becomes the image area other than the predetermined area passes through the charging portion.

An image forming apparatus includes: a photoreceptor including a surface layer; a storage that stores a target value of a variation of a film thickness of the surface layer; and a hardware processor that acquires a variation of the film thickness in a first period within which the photoreceptor rotates a predetermined number of times, and sets a margin that is an amount of a portion for allowance with respect to a proper value of a parameter related to control of the photoreceptor, the margin being to be employed after the first period.

An electrophotographic image forming apparatus includes: an image carrier that carries and conveys a toner image; a charging member arranged in contact with or close to the image carrier; a charging power supply that charges the image carrier; an exposurer that forms a latent image on the charged image carrier; a developing member arranged close to the image carrier; a developing power supply that develops the latent image and forms a toner image on the image carrier; a transfer member that transfers the toner image to a medium; and a hardware processor that controls the image forming apparatus, wherein the hardware processor obtains a potential of an exposure part and a non-exposure part, on the image carrier after the toner image has been transferred to the medium, determines a charging bias based on a difference between the obtained potentials, and determines a developing bias based on the determined charging bias.

In an image forming apparatus, the image bearing member has a surface and configured to rotate about an axis. The collection device is in contact with the surface, and configured to collect materials adhered to the surface. The developing roller is configured to provide a charged toner having a first polarity. The processor is configured to perform: executing a print job in a printing period; executing, in a non-printing period, a first process in which the image bearing member is rotated at least one rotation while a holding bias is applied to the collection device, the holding bias having a second polarity opposite to the first polarity; and executing, in a non-printing period after the first process, a second process in which the image bearing member is rotated while an ejection bias is applied to the collection device, the ejection bias having the first polarity.