A system and method for adjusting transfer parameters in electrostatic-based printers includes a sensor proximate to a paper path before a toner transfer area. A sensor comprised of opposing conductive plates determines a paper property, such as its capacitance, as it passes through an air gap between the conductive plates. A transfer roller receives an electric charge for transferring toner from an associated transfer belt to the paper with a voltage of the electric charge being adjusted based on a transfer parameter corresponding to the sensor data.

In a first image formation mode, an image is formed with a first development contrast C1 and a specific dot pattern is formed with a second development contrast C2, which is lower than the first development contrast C1; in a second image formation mode, an image is formed with a third development contrast C3 and a specific dot pattern is formed with a fourth development contrast C4, which is lower than the third development contrast C3; and when C1 (=C2/C1) denotes a ratio between the second development contrast C2 and the first development contrast C1, and C2 (=C4/C3) denotes a ratio between the fourth development contrast C4 and the third development contrast C3, C2<C1 is satisfied.

An image forming apparatus includes: an image carrier; a charging roller that charges the image carrier; a power supply part that applies a charging voltage to the charging roller; a current measurement part that measures a value of a DC component of a current flowing between the image carrier and the charging roller at at least two timings having mutually different elapsed times; and a hardware processor that measures an elapsed time from a start of application of the charging voltage by the power supply part, calculates a coefficient of an approximate expression indicating a relationship between the value of the DC component of the current flowing between the image carrier and the charging roller, and the elapsed time, and performs judgment related to life of the charging roller on the basis of the coefficient and a predetermined threshold.

An image forming apparatus has an image carrying member, a charging member, an exposing device, a destaticizer, a high-voltage generation circuit, a current detector, and a controller. The controller is configured to execute a contamination state check mode having a potential saturation step where the surface potential of the image carrying member is saturated by applying a DC voltage alone to the charging member, an exposure step where the image carrying member of which the surface potential is saturated is exposed to light in an exposure pattern extending continuously over its entire area in the main scanning direction while being displaced at a constant rate in the sub-scanning direction by the exposing device, and a current detection step where the charging current that passes while the exposure pattern formed on the surface of the image carrying member passes through the charging member is detected by the current detector.

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.

An image forming apparatus includes a photoconductor, a charging member, a voltage applier, a rubbing member, a process executor, a current detector, a characteristic deriver and a process controller. The rubbing member is arranged in contact with a surface of the photoconductor to rub the surface. The process executor executes a refresh process of causing the rubbing member to rub the surface for a predetermined time by supplying toner to the rubbing member. The current detector detects a current value of a current flowing from the charging member to the photoconductor. The characteristic deriver derives an electrical characteristic of 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 process controller determines whether or not to re-execute the refresh process according to the electrical characteristic when the refresh process is finished.

An image forming apparatus includes a developing device that is mountable and dismountable and has a sealing member for sealing to be removed at a time of start using the developing device. The image forming apparatus further includes a winding shaft, a drive source, a detector, and a controller. The winding shaft rotates for removal processing for removing the sealing member. The drive source drives the winding shaft. The detector detects a value corresponding to a load torque applied to the drive source. The controller notifies of an error in a case where the value detected by the detector has become smaller than a predetermined value before a predetermined period of time elapses from start of the drive by the drive source.

An image forming apparatus includes an image forming portion, an image bearing member, a transfer member, a voltage applying portion, a detecting portion, and a controller capable of executing an operation in an adjustment mode in which a chart on which a plurality of test images are transferred by stepwise changing a test voltage applied to the transfer member by the applying portion is formed on a recording material and then a transfer voltage applied to the transfer member by the voltage applying portion during transfer of the toner image is adjusted. The controller is capable of changing a change width per level of the test voltage applied during formation of the chart[[,]] on the basis of a detection result of the detecting portion when the voltage is applied to the transfer member when the recording material on which the chart is formed is in the transfer portion.

According to at least one embodiment, an image forming apparatus includes a heater and a controller. The heater is configured to generate heat. The controller is configured to control AC power to the heater so that a part of the AC power which exceeds a threshold voltage is not applied to the heater.

An image forming apparatus includes: an image former having parts provided in a replaceable manner to be used for image formation; a sensing part that detects a characteristic value of the parts; and a controller that determines whether the characteristic value of the parts, which fluctuates immediately after manufacture, is in a stable state based on a comparison between information regarding the characteristic value of the parts based on a detection result of the sensing part and a threshold value and sets a process condition for the image former based on the detected characteristic value when determining that the characteristic value of the parts is not in the stable state.