A driving force transmission mechanism is a mechanism for transmitting rotational force of the second rotor having a driving-side coupling to a first rotor having a driven-side coupling. The driving-side coupling includes a body and a plurality of second engaging members engaging with first engaging members of the driven-side coupling, each of the plurality of second engaging members has at an abutting point on an abutting surface of a corresponding first engaging member a first inclined surface inclined so as to be away from a rotation axis of the body from a downstream side toward an upstream side in a rotation direction of the body.

An image heating apparatus includes a heater having a first heating block and a second heating block, a heating rotating member to be heated by the heater, a pressure rotating member forming a nip portion for conveying a recording material between the pressure rotating member and the heating rotating member, first temperature detection elements and second temperature detection elements for detecting temperatures of the first heating block and second heating block respectively at positions farther from a recording material conveyance reference position than the first temperature detection elements. In the image heating apparatus, the first temperature detection elements are arranged on a side downstream of the heater in a recording material conveying direction, and the second temperature detection elements are arranged on upstream of the first temperature detection elements in the recording material conveying direction.

An image forming apparatus includes an image forming portion configured to form a developer image on a recording material, a fixing portion configured to heat-fix the developer image to the recording material, a first motor configured to drive the image forming portion, a second motor configured to drive the fixing portion, and a control portion configured to control the first motor and the second motor. The second motor is a stepping motor. The control portion allows the second motor to start rotation at a speed in a self-start region, temporarily stops the second motor at a timing at which the first motor is activated, then allows the second motor to restart rotation at a speed in the self-start region, and changes the speed of the second motor to a speed outside the self-start region before the recording material arrives at the fixing portion.

A replaceable unit for an electrophotographic image forming device includes a housing having a reservoir for holding toner. An electrical connector is positioned on a first side of the housing. The electrical connector includes an electrical contact for contacting a corresponding electrical contact in the image forming device. The electrical contact of the replaceable unit is electrically connected to processing circuitry mounted on the housing. The electrical connector is movable between a first position and a second position. The electrical contact of the replaceable unit moves outward from the first side of the housing along a side-to-side dimension of the housing when the electrical connector moves from the first position to the second position. The electrical contact of the replaceable unit faces downward when the electrical connector is in the second position permitting the corresponding electrical contact to contact the electrical contact of the replaceable unit from below.

An assembly for an image forming device includes an access door movable between an open position permitting replacement of a replaceable unit and a closed position. An electrical connector in the image forming device is movable between a retracted position and an extended position. In the retracted position the electrical connector is disengaged from a corresponding electrical connector of the replaceable unit when the replaceable unit is installed in the image forming device. In the extended position the electrical connector is engaged with the corresponding electrical connector of the replaceable unit. The electrical connector is operatively connected to the access door such that movement of the access door from the closed to the open position moves the electrical connector from the extended to the retracted position and movement of the access door from the open to the closed position moves the electrical connector from the retracted to the extended position.

A photoconductive drum for an electrophotographic image forming device according to one example embodiment includes a cylindrical drum member. A shaft defines a rotational axis of the photoconductive drum. An end cap is positioned at an axial end of the drum member. An electrical contact is positioned against an axially inboard side of the end cap. The electrical contact electrically connects the shaft to the drum member. The electrical contact includes a plurality of projections that contact an inner circumferential surface of the drum member. A plurality of grooves are formed in an outer circumferential surface of the end cap.

An image forming apparatus includes an amorphous silicon photosensitive member, a developing device including a developer carrying member that carries a two-component developer, and a control portion. When a potential difference V0−Vdc between the photosensitive member and the developer carrying member has a first potential difference at which the toner is moved from the developer carrying member to the photosensitive member and a second potential difference at which the toner is moved from the photosensitive member to the developer carrying member, the control portion adjusts V0 or Vdc so that the first potential difference and the second potential difference are equal in value and opposite in polarity, and a first development current |Ia| that flows at the first potential difference and a second development current |Ib| that flows at the second potential difference satisfy 1.9×10.sup.−2≥|Ib|/N≥5.7×10.sup.3 [μA/mm].

A motor control apparatus includes: a current supply unit configured to supply a coil current to a plurality of coils of a motor by controlling a voltage to be applied to the plurality of coils, based on a first command value of an excitation current and a second command value of a torque current; and a control unit configured to control the first command value based on a rotation speed of a rotor of the motor, wherein the control unit is further configured to control, when the rotation speed of the rotor is lower than a first threshold value, the first command value to cause the excitation current to be larger than zero, and control the second command value to supply the torque current in accordance with a load of the rotor.

In an image forming apparatus according to the present disclosure, when a conveyance unit is closed, a second end is disconnected from a ground contact, and a third end makes an electrical connection with a contact spring. When the conveyance unit is opened, the second end makes an electrical connection with the ground contact, and the third end is disconnected from the contact spring.

An image forming apparatus includes a plurality of photosensitive members, a support frame configured to support the plurality of photosensitive members, and an electric unit including a first electric board and a second electric board, and fixed to the support frame. The electric unit includes a first supporting portion extending in an arrangement direction of the plurality of photosensitive members, a second supporting portion extending in the arrangement direction, and a board holding portion configured to hold the first electric board and the second electric board and bridged between the first supporting portion and the second supporting portion. The first electric board is positioned in the image forming apparatus more inward than at least one of the first supporting portion or the second supporting portion in a direction orthogonal to the arrangement direction and a vertical direction.