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 includes a control unit configured to execute a first mode and a second mode. The first mode is a mode in which a toner image is formed on a sheet at a time when a sheet passes through an image formation position for a first time after detecting a property of the sheet by a detection unit. Wherein the second mode is a mode in which a toner image is not formed on a sheet at the time when the sheet passes through the image formation position for the first time after detecting the property of the sheet by the detection unit and is formed on the sheet at a time when the sheet is conveyed via the second conveyance path and passes through the image formation position for a second time.

An image forming apparatus includes an apparatus body including a main contact, and a main guide, and a cartridge including a memory contact, a moving unit moving into and out of the apparatus body in a first direction and including a frame to which the cartridge is attached, first and second protrusions protruding in a second direction orthogonal to the first direction from the end surface of the frame, an intermediate contact being in electrical contact with the memory contact, an unit contact being in electrical contact with the main contact, and a line conductor, the first protrusion being supported by the main guide of the apparatus body, the second protrusion being located above the first protrusion. At least part of the line conductor connecting the intermediate contact and the unit contact is located in a recess formed by the first protrusion, the second protrusion, and the end surface.

An image forming apparatus includes an image forming portion, a supply processing portion, and a second release processing portion. The image forming portion includes a storing portion that stores developer, and forms an image by using the developer stored in the storing portion. The supply processing portion supplies the developer to the storing portion from a developer storing portion attached to an attachment portion, when a storage amount of the developer in the storing portion is less than or equal to a first threshold. The second release processing portion releases regulation on a removal of the developer storing portion when an expected amount of developer to be used by a user is greater than or equal to a reference value that is determined based on a remaining amount of the developer in the developer storing portion attached to the attachment portion.

A driving apparatus includes an endless belt, a belt roller which engages the endless belt, a steering member and an adjustment member. The belt roller has a rotation shaft. The steering member contacts the endless belt at the inner side of the endless belt. The adjustment member is supported rotatably. The adjustment member receives a force in response to the endless belt moving in a longitudinal direction of the rotation shaft of the belt roller, and generates a pressing force that tilts the steering member via a rotational movement of the adjustment member.

A motor control apparatus includes: a switching power supply; a first motor configured to operate with a voltage from the switching power supply; and a control unit configured to control the first motor, wherein the control unit is further configured to cause the switching power supply to supply power of the switching power supply to a load other than the first motor before detecting an initial position of a rotor of the first motor using a current flowing through the first motor.

A printer includes: a first roller feeding a liner; a print unit printing information on a print medium temporarily adhering to the liner fed by the first roller; a second roller located at a first position when performing a print operation in a first print mode, and a second position when performing the print operation in a second print mode, at which second position the second roller rotates by the rotation of the first roller to separate the print medium from the liner; a reflective optical sensor including a light emitting part and a light receiving part arranged in an upward and downward direction defined when the printer is placed on a horizontal surface, and that is used to determine a position of the second roller; and a sensor housing containing the light receiving part. The sensor housing has a surface opposite to the light receiving part. The surface has an opening on a side of the light emitting part, and a light blocking part on a side opposite to the side of the light emitting part.

Disclosed herein is an image forming apparatus. The image forming apparatus includes a sensing unit having a window and a sensor which senses a developer through the window, and a shutter device which opens and closes the window, and thereby the sensing unit in a sensible state is maintained, and a lifetime thereof is extendable.

Disclosed herein is an image forming apparatus. The image forming apparatus includes a sensing unit having a window and a sensor which senses a developer through the window, and a shutter device which opens and closes the window, and thereby the sensing unit in a sensible state is maintained, and a lifetime thereof is extendable.

This image forming apparatus (100) is equipped with: a document set detector (3a, S1, S5); a document size detector (3a, S2, S3, S5); a manual feeder (6) with a manual feed tray (61) that is not equipped with a sensor for detecting the size of set manually-fed paper; a printer (5) that performs printing on the basis of image data; an operation panel (4) that receives setting for feeding paper from the manual feeder (6); and a controller (7) that recognizes the size of a set document and performs manually-fed-paper automatic setting for recognizing the recognized size of the set document as the size of the manually-fed paper.