An image forming apparatus includes a drum unit, a charging roller, a detector, a controller, a developing unit, and a notification unit. The drum unit includes an earth terminal connected to a housing of the image forming apparatus. The detector detects an amplitude of a first alternating-current voltage output to the charging roller. The controller controls so that an amplitude deviation between the first alternating-current voltage amplitude and an output target value of the first alternating-current voltage amplitude is made small. The developing unit develops an electrostatic latent image on the drum unit based on a second alternating-current voltage. The notification unit notifies an abnormality of the earth terminal based on the amplitude deviation in a first state where the first alternating-current voltage is output and the second alternating-current voltage is not output, and the amplitude deviation in a second state where the first and second alternating-current voltages are output.

A recording device includes a recording head that performs recording on a medium, a transport belt that sucks and transports the medium at a position facing the recording head, a charging unit that forms a charging sucking area on the transport belt, in which the medium is sucked by charging, by applying a voltage to the transport belt, and a control section that controls the charging unit. A belt downstream roller pair that transports the medium is provided downstream of the transport belt in a medium transport direction. After a downstream end of the medium is nipped by the belt downstream roller pair, the control section controls the charging unit so that an upstream area downstream of an upstream end of the medium, which is an area including the upstream end of the medium, does not come into contact with the charging sucking area of the transport belt.

An image forming apparatus includes an image carrier, a charging device, a developing device, a developing power source, a current measuring device, and a processor. On a surface of the image carrier, an electrostatic latent image is formed. The charging device electrically charges the image carrier. The developing device forms a toner image, by supplying toner to the image carrier and developing the electrostatic latent image formed on the image carrier. The developing power source applies a predetermined bias voltage to the developing device. The current measuring device measures a developing current flowing in the developing device. The processor acts, by executing a control program, as a calculator that calculates a surface potential of the image carrier, on a basis of the developing current measured by the measuring device.

An image forming apparatus including a control unit configured to execute a first mode and a second mode of forming images on first through third image bearing members. In the first mode, a toner image is formed on a third image bearing member without having toner images formed on first and second image bearing members in a state where the first through third image bearing members are abutted against an intermediate transfer body. In the first mode, the control unit controls at least a first charging device such that a primary transfer contrast in a first primary transfer portion is set equal to or greater than a discharge starting voltage, and applies an AC voltage to a second charging device such that a discharge current having a current quantity smaller than that in the second mode.

An image forming apparatus includes an image carrier, a charging device, an exposure device, a development device, a transferring part, a development bias applying part, an electric current detection part, a density detection part and a bias condition determination part. The bias condition determination part performs a DC voltage determination mode (a DC calibration) determining a reference DC voltage serving as a reference of a DC voltage of a development bias applied to a development roller and a peak-to-peak voltage determination mode (an AC calibration) determining a reference peak-to-peak voltage serving as a reference of a peak-to-peak voltage of an AC voltage of the development bias. When a difference between the reference DC voltages determined the successive DC voltage determination modes exceeds a predetermined threshold value, the bias condition determination part performs the peak-to-peak determination mode.

Provided is an image forming method using an electrophotographic photoreceptor and a toner for developing an electrostatic charge image, and including at least a charging step, an exposure step, a developing step, and a transfer step, wherein the electrophotographic photoreceptor has a photosensitive layer, and the photosensitive layer contains a compound having a structure represented by the following Formula (1) or Formula (2); and in the developing step, the toner for developing an electrostatic charge image containing titanic acid compound particles doped with at least lanthanum as an external additive is used,

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An image forming apparatus includes a high voltage generating circuit, a voltage controller, a current detector, and a recovery process controller. If two inflection points (O and P) exist, which exist on a characteristic curve indicating a relationship between the voltage value and the current value when the frequency of the AC voltage is set as a first frequency or when a photosensitive drum is rotated at a first linear speed, the recovery process is performed if a potential difference between a first inter-inflection-point voltage (OP) between inflection points and a second inter-inflection-point voltage (OP′) between inflection points (O′ and P′) when setting a second frequency different from the first frequency, or a potential difference between the first voltage and a third inter-inflection-point voltage (OP″) between inflection points (O″ and P″) when setting a second linear speed different from the first linear speed becomes a predetermined value or less.

The image forming apparatus includes a control unit configured to selectively execute an operation for applying a voltage with a polarity opposite to an original charging polarity of a toner to a first charging member and a second charging member and an operation for applying a voltage with the polarity opposite to the original charging polarity of the toner to one of the first charging member and the second charging member and a voltage with the same polarity as the original charging polarity of the toner to another of the first charging member and the second charging member as a cleaning operation for charging a secondary transfer residual toner to the polarity opposite to the original charging polarity of the toner by using the first charging member and the second charging member to transfer the secondary transfer residual toner onto an image bearing member.

An image forming apparatus includes an image forming section that includes a latent image bearer; a charger to charge a surface of the latent image bearer; and a latent image writer to write a latent image on the charged surface of the latent image bearer. The image forming apparatus further includes a developing device to develop the latent image with a developer borne on a developer bearer; and a cyclical changing device including a controller and a write controller, in combination. The cyclical changing device cyclically changes a developing bias to be applied to the developer bearer while cyclically changing a charge intensity of the charger during the image formation by the image forming section. The cyclical changing device cyclically changes the developing bias and the charge intensity, and a latent image write intensity of the latent image writer.

According to one embodiment, a charger charges a surface of an image carrier by discharge in a wide-angle. A charging bias voltage application section applies a charging bias voltage to the charger. An exposing device forms an electrostatic latent image in a charged image carrier. A toner carrier causes toner to adhere to the electrostatic latent image formed in the image carrier. A developing bias voltage application section applies the developing bias voltage to the toner carrier. In addition, the developing bias voltage application section changes the charging bias voltage in one step and changes the developing bias voltage applied to the toner carrier in multiple steps.