An image forming apparatus includes: an image holder configured to hold an image formed using an electrographic process; a transfer body that faces the image holder and is configured to contact the image holder while rotating to form a secondary transfer region; an application unit configured to apply a voltage for charging the secondary transfer region; and a charge unit that faces a region other than the secondary transfer region of the transfer body and is configured to charge a surface of the transfer body with a polarity opposite to an applied voltage of the application unit.

A control portion executes: a step of calculating a surface potential of an image bearing member charged by a charging member, to which a predetermined voltage is applied, and exposed to light by a predetermined exposure amount on the basis of a discharge start voltage between a measurement member and the image bearing member and calculating a correction value from a difference between a target value and calculated surface potential of the image bearing member; a step of correcting calculated surface potential of the image bearing member on the basis of the correction value; and a step of controlling at least one of the voltage applied to the charging member and an exposure amount of the exposure apparatus on the basis of the corrected surface potential of the image bearing member so that the surface potential of the image bearing member reaches the target value.

An image forming apparatus includes an image carrier that is capable of holding an image on a surface thereof while rotating, an image forming unit that forms the image on the image carrier, a transfer unit that transfers the image from the image carrier to a medium while rotating, a transport unit that circulates as the transfer unit rotates and that transports the medium to a transfer region while holding the medium, and a control unit that changes a timing at which the image forming unit forms the image in accordance with variation in a ratio of a rotation velocity of the transfer unit to a rotation velocity of the image carrier.

An image forming apparatus includes a photoconductive drum, a developing roller, a humidity sensor configured to detect a humidity, and a controller configured to execute a single-side printing, a first-double-side printing and a second double-side printing. The controller is configured to execute the first double-side printing in which images are printed at a first developing-bias voltage on both the first surface and the second surface of the sheet when the humidity detected by the humidity sensor is greater than a threshold value. The controller is configured to execute the second double-side printing in which an image is printed at a second developing-bias voltage, which is less than the first developing-bias voltage, on the second surface of the sheet when the humidity detected by the humidity sensor is equal to or less than the threshold value.

A server apparatus including a first communication device and a first computing device. The first communication device communicates with an image forming apparatus via a network. The first computing device includes a processor, and acts as a data acquirer, a dimension reduction processor, and a residual service life calculator, when the processor executes a first control program. The data acquirer acquires observation data of a first number of dimensions from the image forming apparatus, via the first communication device. The dimension reduction processor converts the observation data of the first number of dimensions into characteristic data of a second number of dimensions fewer than the first number of dimensions. The residual service life calculator calculates a residual service life of a replaceable unit in the image forming apparatus, on a basis of the characteristic data.

A feeding apparatus includes a feeding unit, an ion generating unit and a controller. The ion generating unit irradiates the sheet fed by the feeding unit with the ion. The controller acquires an information on the fed sheet and to controls the ion generating unit. The controller operates the ion generating unit in a case that the information of the sheet is a first information, and does not operate the ion generating unit in a case that the information of the sheet is a second information.

Disclosed is a sheet feeding apparatus configured to be attached to an image forming apparatus. The sheet feeding apparatus includes a frame body and a locking member provided on an upper part of the frame body, the locking member being configured to be movable between a locking position where the frame body is locked to the image forming apparatus and a releasing position where the locking of the frame body is released, wherein in attaching the heating unit to an attaching position of the frame body, the locking member is configured to restrict a movement of the heating unit to the attaching position by interfering with the heating unit when the locking member is located at the releasing position and to allow a movement of the heating unit to the attaching position when the locking member is located at the locking position.

An image forming apparatus, having a main body housing including an air outlet opening, a photosensitive drum, a fuser to thermally fix toner transferred from the photosensitive drum to a sheet on the sheet, a fan to generate an airflow toward the air outlet opening, and a controller, is provided. The controller is configured to, in a continuous stage of printing continuous from a beginning stage, count a cumulative printed page number being a cumulative number of pages printed by the image forming apparatus, in a case where the cumulative printed page number is smaller than a first page number, control the fan to rotate at a first speed, and in a case where the cumulative printed page number is equal to or larger than the first page number, control the fan to rotate at a second speed, the second speed being higher than the first speed.

An image forming apparatus includes an image bearing member, a transfer member, a power source, a detecting portion, a controller, an environment detecting portion, and a contact member. In a case that an absolute water content acquired on the basis of environmental information is a predetermined threshold or more, the controller sets a limit voltage on the basis of a detection result of the detecting portion in a state in which the recording material is absent in a transfer portion, and the controller controls the power source so that an absolute value of a voltage applied from the power source to the transfer member during contact of the recording material with the transfer member and the contact member is an absolute value or less of the limit voltage.

A heating device has a first rotating member that is heated by a heat source, and a second rotating member that forms a nip portion with the first rotating member, such that a recording material is heated up at the nip portion. The heating device further has: a first cover disposed along an outer peripheral surface of the first rotating member, so as to surround the first rotating member, and a second cover, disposed between the first cover and the first rotating member, and having a protruding portion that protrudes towards the first rotating member. In a longitudinal direction of the first rotating member, a length of the first rotating member is a first length, and a length of the protruding portion is a second length that is smaller than the first length.