An image forming apparatus includes a photoconductor, a power supply, and circuitry. The power supply is configured to apply a charging voltage to the photoconductor. The circuitry is configured to control film thickness detection of detecting a charging current corresponding to the charging voltage to detect a film thickness of a surface of the photoconductor. The circuitry is further configured to determine a sampling period taken to detect the charging current; calculate a variation in the charging current detected; and determine whether the variation is greater than a threshold. The circuitry is configured to: determine the sampling period according to a determination result as to whether the variation is greater than the threshold; and sample the charging current for the sampling period determined, on a subsequent film thickness detection control.

An image forming apparatus includes a detecting unit detecting a value of a current flowing to a photosensitive member when a voltage is supplied to a voltage applying member or a value of a voltage applied to the photosensitive member when a current is supplied to the voltage applying member, an acquiring unit acquiring information concerning a difference between potentials of the unexposed portion and the exposed portion, based on detection results of the detecting unit at times when the voltage is applied by the voltage applying member to each of an unexposed portion formed in a region chargeable by a charging member in a rotation axis direction of the photosensitive member and an exposed portion formed in a region exposable by the exposure device in the rotation axis direction of the photosensitive member, and a control unit controlling an image forming condition based on the information concerning the difference.

An image forming apparatus includes a controller configured to execute a mode for correcting a transfer voltage during a continuous image forming job of forming an image on a plurality of recording materials. The controller is configured to correct the transfer voltage on the basis of detection results which are detected by a voltage detection unit and a current detection unit during a predetermined time.

An image forming apparatus calculates a post exposure potential after exposure by an exposure device based on a first charge voltage, a second charge voltage, a charge current in a first change characteristic when a transfer voltage is the first charge voltage, a charge current in a second change characteristic when the charge voltage is the first charge voltage, a charge current in the first change characteristic when the charge voltage is the second charge voltage, and a charge current in the second change characteristic when the charge voltage is the second charge voltage, and makes a determination as to life of an image carrier based on the post exposure potential.

An image forming apparatus includes a latent image bearer, an electrostatic latent image forming device, a potential sensor, a toner image forming device, a toner adhesion amount detector, and circuitry. The circuitry controls the electrostatic latent image forming device to create an adjustment pattern on the latent image bearer when the image forming apparatus is not printing, controls the potential sensor to detect an electric potential of the adjustment pattern, controls the electrostatic latent image forming device and the toner image forming device to create a test toner image during a printing period, controls the toner adhesion amount detector to detect a toner adhesion amount of the test toner image, and adjusts at least one image forming condition of the electrostatic latent image forming device and the toner image forming device based on the electric potential of the adjustment pattern and the toner adhesion amount of the test toner image.

An image forming apparatus that forms an image on a transfer material in an image forming mode, includes: a photoreceptor rotatable in a predetermined rotation direction; a developer that forms a toner image on the photoreceptor using a two-component developing agent including toner and a carrier; a transferor that transfers the toner image on the photoreceptor onto the transfer material; a carrier collector that applies an electric field corresponding to a collecting bias to a carrier adhering to the photoreceptor to collect the carrier; a carrier detector that detects a carrier remaining on the photoreceptor after collecting the carrier by the carrier collector; and a hardware processor that sets the collecting bias in the image forming mode on the basis of the amount of carriers detected by the carrier detector when a carrier adhesion detecting mode for forcibly causing a carrier to adhere to the photoreceptor is executed.

In an example, a method includes charging a photoconductive surface in a print apparatus and monitoring an electrical parameter associated with a proximity of a print apparatus component to the photoconductive surface. A relative spacing between the print apparatus component and the photoconductive surface may be changed and a contact between the print apparatus component and the photoconductive surface may be detected when the electrical parameter meets predetermined criteria.

In an image forming apparatus of a direct transfer system, when in a region where a transfer nip portion of a photosensitive drum is formed, a region in which the toner image can be formed is defined as a first region, and a region where the recording medium does not pass while the recording medium is conveyed by the transfer nip portion is defined as a second region, in forming the toner image on the recording medium, the photosensitive drum enters the transfer nip portion in a state where the second region of the photosensitive drum includes a region in which an absolute value of a surface potential is smaller than an absolute value of a surface potential of a region in which the toner image is not formed in the first region.

An image forming apparatus includes a photoconductor, a charging member, a voltage applier, a storage unit, a current detector, a characteristic deriver and a voltage setter. The storage unit stores in advance relationship information representing a relationship between an electrical characteristic of discharge products adhering to the surface and a proper inter-peak voltage value capable of properly charging the surface. The current detector detects a current value of a current flowing from the charging member to the photoconductor. The characteristic deriver derives the electrical characteristic of the discharge products adhering to the surface on the basis of an oscillating voltage applied to the charging member by the voltage applier and the current value. The voltage setter sets the proper inter-peak voltage value corresponding to the electrical characteristic derived by the characteristic deriver in the relationship information as the inter-peak voltage value of the alternating-current voltage.

Examples of charging a photoconductive layer in an image forming apparatus are described. In one example, a method includes applying a charging voltage to the photoconductive layer and measuring surface voltages of the photoconductive layer at a plurality of positions on the photoconductive layer. Based on the measured surface voltages, a correction voltage profile is determined. The determined correction voltage profile includes at least a first correction voltage associated with a first position on the photoconductive layer and a second correction voltage associated with a second position, different to the first position, on the photoconductive layer. The method includes applying the first correction voltage to the photoconductive layer and applying the second correction voltage to the photoconductive layer.