Abstract: A photosensitive member cartridge, including a photosensitive member, is provided with a lock device and a protection wall for the lock device. A developer cartridge includes a developer containing chamber and an inlet. The inlet is disposed so that the protection wall for the lock device at least partially overlaps the inlet when the developer cartridge is received in the photosensitive member cartridge.

Abstract: An image forming apparatus includes: a main body; a process cartridge detachably attachable to the main body, the process cartridge including an image carrier configured to carry a developer image thereon and a cartridge frame; a feeding path configured to feed a recording sheet to a transfer position where the developer image carried on the image carrier is transferred to the recording sheet; and a returning path configured to return the recording sheet that has passed the transfer position to the feeding path. The cartridge frame defines at least a part of the feeding path and at least a part of the returning path.

Abstract: A cartridge includes; a first gear rotatably provided at the casing; a second gear including a toothed portion and a toothless portion; and a storing portion configured to store the second gear. The second gear includes an arm that is flexible and extends substantially along a peripheral direction of the second gear. An inner peripheral surface of the storing portion includes a bulging portion that bulges inward in a radial direction. The bulging portion has a peak portion closest to a rotation center of the second gear. The arm is deflected while the arm contacts the bulging portion. The deflection of the arm is changed from an increasing tendency to a decreasing tendency at the peak portion as a base point. The toothed portion of the second gear is separated from the first gear when the end portion of the arm has crossed over the peak portion.

Abstract: An image forming apparatus includes: a transfer member that transfers a developer image onto a transfer medium to form an image on the transfer medium; a bias applying unit that applies a transfer bias to the transfer member; and a bias control unit that controls the transfer bias to be applied to the transfer member by the bias applying unit, wherein a longitudinal length of the transfer member is formed to be shorter than a width of the transfer medium having a maximum width on which the image is to be formed with the image forming apparatus.

Abstract: A cartridge according to one aspect of the invention is detachably attachable to a main body including a first terminal. The cartridge comprises: a case; a memory device configured to store information concerning the cartridge; a cover member configured to cover a part of the case and movably supported on the case to allow a relative movement to the case; and a second terminal provided at the cover member and electrically connected to the memory device. In a state where the cartridge is attached to the main body, the second terminal contacts with the first terminal of the main body.

Abstract: An image forming apparatus of one aspect of the invention comprises: an image carrier; a developing device configured to hold a developer carrier to supply developer to the image carrier, the developing device movable to a contacting position where the developer carrier contacts the image carrier and to a spaced position where the developer carrier is spaced from the image carrier; and a memory element disposed in the developing device. The developing device comprises: a pressing force input portion configured to receive pressing force to make the developer carrier contact the image carrier; and a spacing force input portion configured to receive spacing force to make the developing device move from the contacting position to the spaced position. At least one of the pressing force input portion and the spacing force input portion comprises a terminal electrically connected to the memory element.

Abstract: An image forming device according to an aspect of the invention comprises: a main body; and a first cartridge capable of accommodating a developer and detachably attached to the main body. The first cartridge comprises: a rotation body rotatably provided in the first cartridge; a memory device configured to store information concerning the first cartridge; and a first terminal electrically connected to the memory device. The main body comprises: a driver configured to rotate the rotation body; and a second terminal connected to the first terminal. The first terminal is provided at a position where a rotation moment produced by rotation of the rotation body acts in the first cartridge.

Abstract: A cartridge includes an engagement gear which includes a first engaging portion and is configured to selectively rotate. The cartridge also includes a rotational body which includes a second engaging portion, and a center axis of the rotational body is aligned with a center axis of the engagement gear. Moreover, the cartridge includes an extension portion which is positioned offset from a center of rotation of the rotational body. The engagement gear and the rotational body are configured to selectively be positioned in one of a first state in which the second engaging portion and the first engaging portion are separated from each other, and a second state in which the second engaging portion engages the first engaging portion. The rotational body is configured to rotate with the engagement gear when the engagement gear rotates and the engagement gear and the rotational body are in the second state.

Abstract: An image forming apparatus according to one aspect of the invention comprises: a main unit; and a developer cartridge detachably attached to the main unit. The developing cartridge comprises: a rotation body having a rotational axis and rotatable in a rotation direction; and one rotational arm of a first rotational arm or two rotational arms of the first rotational arm and a second rotational arm which are rotatable around the rotational axis. The main unit comprises: a swingable detecting arm; an elastic member that urges the detecting arm toward a neutral position. When the developer cartridge is attached to the main unit, the first rotational arm contacts with the detecting arm to swing in a first swing direction from the neutral position. When the rotation body rotates by a predetermined rotation amount, the second rotational arm contacts with the detecting arm in a second direction from the neutral position.

Abstract: The invention describes an image forming apparatus having a cartridge configured to be removably attached to a main body. The cartridge has a rotational body positioned within the cartridge and an extension portion protruding outward from the rotational body in an axial direction. The device body has a main body, which has a driving member that rotates the rotational body and the extension portion, a detecting unit for detecting a movement of the extension portion, and a determining unit for determining a type of the developer cartridge using either a time elapsed between a time in which the driving member begins driving the rotational body and a time in which the detecting unit detects the movement of the extension portion, or a drive amount of the drive device occurring during an elapsed time.

Abstract: An image forming apparatus comprises: a main unit; and a developer cartridge detachably attached to the main unit. The developer cartridge comprises: a rotational body having a rotational axis and rotatable in a rotation direction; and an extended portion formed on the rotational body to extend along the rotational axis, the extended portion rotatable around the rotational axis. The main unit comprises: a driving unit configured to rotate the rotational body in the rotation direction; a detecting unit configured to detect a movement of the extended portion and an extending amount of the extended portion; and a determining unit configured to: determine whether the developer cartridge is a new product according to a presence of a movement of the extended portion detected by the detecting unit; and determine type of the developer cartridge based on the extending amount of the extended portion detected by the detecting unit.

Abstract: A motor control apparatus includes a first FG pattern for generating a first induced voltage attendant upon rotation of the rotor of a motor; a second FG pattern for generating a second induced voltage due to noise; a differential amplifier for differentially amplifying the first and second induced voltages, which are input thereto; and a motor speed control unit for controlling rotation of the motor so as to achieve synchronization between the output of the differential amplifier and a prescribed frequency signal.

Abstract: A fixing apparatus has a first heating member and a second heating member provided in a heating portion, and a current control unit which controls an AC current to be supplied to the heating portion, The current control unit executes a wave number control, on the AC current supplied to the heating portion, in a unit of predetermined number of half-waves so that an AC current to the first heating member is supplied in a positive-negative symmetrical pattern in the unit of predetermined number of half-waves; an AC current to the second heating member is supplied in a positive-negative symmetrical pattern in the unit of predetermined number of half waves; AC currents to the first and second heating members are supplied in a positive-negative symmetrical pattern in total in the unit of predetermined number of half-waves and the current control unit increases the duty ratio alternately for the first heating member and the second heating member.

Abstract: A fixing apparatus has a first heating member and a second heating member provided in a heating portion, and a current control unit which controls an AC current to be supplied to the heating portion. The current control unit executes a wave number control, on the AC current supplied to the heating portion, in a unit of predetermined number of half-waves so that an AC current to the first heating member is supplied in a positive-negative symmetrical pattern in the unit of predetermined number of half-waves; an AC current to the second heating member is supplied in a positive-negative symmetrical pattern in the unit of predetermined number of half-waves; AC currents to the first and second heating members are supplied in a positive-negative symmetrical pattern in total in the unit of predetermined number of half-waves and the current control unit increases the duty ratio alternately for the first heating member and the second heating member.

Abstract: A process cartridge includes an image bearing member, a brush, and a supporting portion. The brush includes a base member having an elongated plate shape that extends in the longitudinal direction, a brush member including bristles provided on the front surface of the base member, and mounting portions formed at both latitudinal ends of the base member. The supporting portion includes holding portions that hold the mounting portions formed at the both latitudinal ends of the base member, thereby supporting the brush with respect to the image bearing member.