An image forming apparatus, including: a photoconductor configured to be rotatable; a charger configured to charge the photoconductor; an overcurrent detector configured to output an overcurrent detection signal in response to detection of an overcurrent in the charger; and a controller, wherein the controller is configured to execute: an obtaining process of obtaining the overcurrent detection signal output from the overcurrent detector; a first counting process of counting a first number of detections based on the overcurrent detection signal obtained in the obtaining process, the first number of detections being the number of the overcurrent detection signals synchronized with a first cycle corresponding to one rotation of the photoconductor; and a first determining process of determining whether the first number of detections is not smaller than a first threshold which is not smaller than 2.

A method of operating an electrophotographic printer (100) to control the optical density of a printed image is described. The method comprises providing a printing substance on a transfer member (104); emitting a pulse of heat to heat the printing substance on the transfer member to increase flowability of the printing substance on the transfer member; and transferring, from the transfer member to a substrate (108), the printing substance heated by the pulse of heat so as to provide the printed image on the substrate.

A corona discharger includes a discharge wire and holding portions for holding the discharge wire at longitudinal opposite end portions thereof. The discharge wire comprises a base material of metal, and a surface layer of the material comprises carbon on a part thereof. The discharge wire includes a coated region coated with the surface layer, and non-coated regions at opposite sides of the coated region with respect to the longitudinal direction of the discharge wire. Opposite end portions of the discharge wire are in the non-coated regions.

An electrophotographic imaging device includes a charging device, a cleaning device, and a fuser member that each include hydrophobic carbon nanotubes. The use of hydrophobic carbon nanotubes can increases the charging device's, the cleaning device's, and the fuser member's durability, conductivity, and contaminants deposition.

An image forming apparatus includes a corona charger including a discharging wire, a grid electrode, for charging a photosensitive drum at a charging position; and an exposure device for exposing the drum charged by the charger at an exposure position which is in a downstream side of the charger in a rotational direction of the drum at the charging position. The grid electrode includes a first portion having openings and a second portion having only a non-opening portion in a charging region for charging the drum in a longitudinal direction of the charger, and the second portion includes a downstream side peripheral portion at a downstream end of the grid electrode with respect to the rotational direction. In a cross-section orthogonal to the longitudinal direction and including the charging region, the downstream side peripheral portion is intersected by a straight line passing through the exposure position and the wire.

A charging device includes a first cleaning member that cleans a surface of a charging wire by moving along the wire while being in contact with the wire at a first side; and a second cleaning member that cleans the surface of the wire by moving while being in contact with the wire at a second side, and moving relative to the first cleaning member in a crossing direction that crosses a wire length direction.

A movable member includes a frame, a mounting portion, a rotatable image bearing member, a charging member, and a cleaning member. The cleaning member includes a base portion including a first surface positioned on one side of the frame, a second surface positioned on the other side of the frame, and a third surface, and includes a projected portion. The projected portion includes a first side surface positioned on the aforementioned the other side and a second side surface positioned on the aforementioned one side. The first side surface is positioned between the first surface and the second surface. The first side surface constitutes an end surface of the projected portion on the aforementioned the other side with respect to the axial direction, and the second side surface constitutes an end surface of the projected portion on the aforementioned one side with respect to the axial direction.

An image forming apparatus includes an image carrier, a charging device, an exposure device, a development device, and a development voltage power supply. The development device includes a development container storing a nonmagnetic one-component developer composed only of a toner, and a developer carrier on which a toner layer is formed on an outer circumferential surface thereof. The development voltage power supply applies a development voltage to the developer carrier. The image forming apparatus alternately forms white regions and exposed regions at a predetermined pitch repeatedly on a surface of the image carrier to form a solid image with an area ratio lower than 100%. Where V0 represents a white-region potential of the image carrier, VL represents an exposed-region potential of the image carrier, Vt represents a toner-layer potential, and Vd represents the development voltage, Vd?0.5*(V0?VL)+VL?Vt is fulfilled.

An image forming apparatus, including: a photoconductor configured to be rotatable; a charger configured to charge the photoconductor; an overcurrent detector configured to output an overcurrent detection signal in response to detection of an overcurrent in the charger; and a controller, wherein the controller is configured to execute: an obtaining process of obtaining the overcurrent detection signal output from the overcurrent detector; a first counting process of counting a first number of detections based on the overcurrent detection signal obtained in the obtaining process, the first number of detections being the number of the overcurrent detection signals synchronized with a first cycle corresponding to one rotation of the photoconductor; and a first determining process of determining whether the first number of detections is not smaller than a first threshold which is not smaller than 2.

An image forming apparatus includes a photosensitive member, a corona charger including a discharging electrode and a grid electrode having a surface layer containing a carbon atom as a main component and configured to electrically charge the photosensitive member under application of a voltage to the discharging electrode and the grid electrode, and an output portion configured to output information on a lifetime of the grid electrode. The output portion outputs the information on the basis of an index value of an amount of use of the grid electrode correlating with a product of a value of a grid current flowing through the grid electrode and a time of flowing of the grid current through the grid electrode.