An image forming apparatus that forms an image on a sheet under an operation condition set depending on a sheet type, includes a hardware processor that: detects whether the sheet type is any one of a plurality of assumed types; performs control such that an activation operation for forming the image under an interim condition, which is an operation condition corresponding to one of the plurality of assumed types, is performed before detecting the sheet type; determines whether or not a recovery operation for optimizing a state of image formation is performed before starting image formation under a determinate condition, which is an operation condition corresponding to the detected type; performs control such that the recovery operation is performed when it is determined that the recovery operation is performed; and performs control such that the image formation is performed under the determinate condition after the recovery operation is performed.

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 a movable photosensitive member, first and second corona chargers, an adjusting mechanism, a developing device, a detecting member configured to detect a surface potential of the photosensitive member at a plurality of positions with respect to the widthwise direction of the photosensitive member, an input portion, and a display portion. In accordance with input of an instruction to the input portion, the detecting portion detects at least two surface potentials of three surface potentials including the surface potential of the photosensitive member after being charged by the first and second corona chargers, the surface potential of the photosensitive member after being charged by the first corona charger, and the surface potential of the photosensitive member after being charged by the second corona charger. A detection result of the detecting member is displayed at the display portion.

Provided is an image formation device including a photoreceptor configured to carry a toner image and a developer configured to form the toner image on a surface of the photoreceptor and configured such that the developer is a replaceable development unit, the image formation device including: a development bias application section configured to apply a development bias to between the photoreceptor and the developer; a stabilization control section configured to perform image stabilization control of determining a development bias value to be used in future by changing the development bias while measuring a density of the toner image formed by the developer, thereby obtaining the toner image with a target density; and a life determination section configured to determine expiration of use of the development unit when the development bias value determined by the stabilization control falls outside a preset acceptable range.

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 member arranged in contact with or in proximity to an image carrier, a sensor for measuring an electrical characteristic value of the member, a power supply which switches from a first mode in which one of a constant current and a constant voltage is applied to the member to a second mode in which the other is applied to the member, a storage which stores first correspondence between an amount of use of the member in the first mode and the electrical characteristic value, and a hardware processor. The hardware processor obtains second correspondence between the electrical characteristic value measured with the sensor and the amount of use of the member in the first mode and predicts a serviceable period of the member when the power supply is switched to the second mode based on the first and the second correspondences.

A controller develops a plurality of electrostatic latent images for detection, formed by constituting a developing contrast, into toner images (S1, S2), and acquires current values fluctuating by an amount of toner remaining on a developing roller after development of the electrostatic latent images (S3). On the basis of a developing contrast at which the device falls within a predetermined range due to that a development efficiency reaches an almost upper limit by utilizing that the current value becomes small with a decrease in toner amount in a case that the development efficiency is high compared with a case that the development efficiency is low (YES of S4), a developing contrast to be used during image formation is set. When the development is carried out at the set developing contrast, the electrostatic latent image can be developed into the toner image while maintaining the high development efficiency and toners with many particle sizes in a liquid developer can be used for development, so that it is possible to suppress that the electrostatic latent images are developed into toner images low in image density.

An image forming apparatus includes a photoconductor, a charging roller for charging the photoconductor, a current sensor for detecting a value of current flowing through the photoconductor or the charging roller as a result of application of voltage to the charging roller, an acquisition sensor for acquiring an environment value representing an environment state inside the image forming apparatus, and a processor configured to estimate a film thickness of the photoconductor, based on a value of current detected by the current sensor when a state in which the environment value falls within a predetermined range continues for a predetermined time or longer.

The present disclosure provides a process cartridge and a potential detection part. The process cartridge includes a cartridge body, a photosensitive drum rotatably installed at the cartridge body, and a potential detection part configured to detect an electrical signal on the image-forming region. The potential detection part includes a detection starting portion and a detection ending portion; the detection starting portion and the detection ending portion respectively correspond to a detection starting position and a detection ending position of a detectable region of the potential detection part along a first direction; a maximum distance along the first direction between orthographic projections of the detection starting portion and the detection ending portion on the image-forming region is L1; a length of the image-forming region along the first direction is L2; the first direction is in parallel with an axis direction of the photosensitive drum; and L1/L2>?.

An image forming apparatus includes: multiple intermediate-transfer-member density sensors that are disposed in the axial direction of an intermediate transfer member and that detect corresponding densities of a developer image having been subjected to first transfer onto the intermediate transfer member; and a processor configured to: in response to occurrence of a variation of density on a recording medium, if a relationship between the highest density value and the lowest density value among the density values detected by the respective intermediate-transfer-member density sensors indicates a first density state, output information indicating that the variation of density is caused in a process of or after a second-transfer process in which the developer image having been subjected to first transfer onto the intermediate transfer member is transferred onto the recording medium; and if the relationship indicates a second density state opposite to the first density state, output information indicating that the variation of density is caused in a process before the second-transfer process.