Abstract: An access restriction device for a consumable component of an apparatus body includes an access restriction cover is rotatably attached to a side surface of the apparatus body; a lock mechanism to lock and unlock opening of the cover; the cover openable in an unlocked state of the lock mechanism; a hinge portion disposed at a lower position in a direction of gravity and a position closer to the apparatus body in a horizontal direction than a center of gravity of the cover in a closed state of the cover, the cover being rotatably coupled to the apparatus body via the hinge portion; and an engaged portion disposed at a position higher in the direction of gravity than the center of gravity of the cover in the closed state. The cover is engaged with an engaging portion of the lock mechanism via the engaged portion.

Abstract: An access restriction device for a consumable component of an apparatus body includes an access restriction cover is rotatably attached to a side surface of the apparatus body; a lock mechanism to lock and unlock opening of the cover; the cover openable in an unlocked state of the lock mechanism; a hinge portion disposed at a lower position in a direction of gravity and a position closer to the apparatus body in a horizontal direction than a center of gravity of the cover in a closed state of the cover, the cover being rotatably coupled to the apparatus body via the hinge portion; and an engaged portion disposed at a position higher in the direction of gravity than the center of gravity of the cover in the closed state. The cover is engaged with an engaging portion of the lock mechanism via the engaged portion.

Abstract: A sheet conveyance device for conveying a recording medium includes a fixed roller, a movable roller, an urging member, and a shock absorber, and an image forming apparatus including the sheet conveyance device. The position of the fixed roller is fixed. The movable roller is disposed opposite the fixed roller to contact the fixed roller, thereby defining a nip. The urging member urges the movable member to contact the fixed roller in the absence of the recording medium in the nip and allows the movable member to separate from the fixed roller by an amount corresponding to a thickness of a recording medium when the recording medium enters the nip. The shock absorber absorbs displacement energy generated when the urging member urges the movable roller to contact the fixed roller again after the recording medium passes through the nip.

Abstract: A drive transmitter, including a first rotational axis transmitting a drive force of a drive source to a first rotator, a second rotational axis transmitting a drive force of the drive source to a second rotator, and an idler gear configured to transmit a drive force to the second rotational axis; wherein the first rotational axis penetrates the idler gear with a gap therebetween.

Abstract: A synchronized drive unit, including a drive member including a pulley; a driven member including a pulley; a relay member including to transmit a power; and timing belts hung around the drive and driven members through the relay member with tension and rotates the drive and driven members in synchronization, wherein each of the timing belts is formed of plural narrow timing belts parallely placed in a rotational axis direction of the pulley and the narrow timing belts are located on the driven member so as to counteract their eccentric components each other.

Abstract: An image forming apparatus includes an endless belt member; a drive unit moving the endless belt member; a first detecting unit detecting a rotating speed of the drive unit; a second detecting unit detecting an endless transport speed of the endless belt member; and a control unit controlling the rotating speed of the drive unit based on a first detection signal from the first detecting unit or a second detection signal from the second detecting unit selectively depending on a selection condition. Upon selection of the first detection signal in accordance with the selection condition, the control unit corrects the rotating speed of the drive unit using the second detection signal such that an average value of the endless transport speed of the endless belt member approaches a target average value.

Abstract: An image forming apparatus includes a rotating member, a motor configured to rotate the rotating member, and a marking member having primary and secondary portions. The image forming apparatus also includes a mark sensor configured to detect the primary and secondary portions, and output a primary signal and a secondary signal, and a position sensor configured to determine a rotational position of the rotating member based on a primary reception time of one of the primary and secondary signals that comes immediately after the other of the primary and secondary signals when the position sensor receives the other of the primary and secondary signals at a start of a mark detecting operation. Further, the image forming apparatus includes a motor controller configured to control the motor based on the recognition result and make the rotational position consistent with a target position at a predetermined time during the mark detecting operation.

Abstract: A main controlling part is configured to choose and execute either a constant belt speed control which controls a driving motor (a driving source for an intermediate transfer belt) to move the intermediate transfer belt at a predetermined target belt speed or a constant motor speed control which rotates the driving motor at a predetermined target rotational speed according to a print command, and then, prior to a first-time print job, after executing a writing position correcting process while moving the intermediate transfer belt under the constant belt speed control, forms a color shift detecting image by switching from the constant belt speed control to the constant motor speed control, measures a difference between amounts of color shift, and executes a speed correcting process for correcting the target rotational speed of the driving motor in the constant motor speed control based on the measurement result.

Abstract: A printer according to the present invention is a so-called tandem-type printer, and has a configuration that a motor gear is directly connected to an M-photoconductor driving gear and an idler gear is directly connected to a Y-photoconductor driving gear and the M-photoconductor driving gear. A diameter of the Y and M photoconductors driving gear, a distance between transfer sections of the Y and M photoconductors, a motor gear input angle, and an idler input angle are set so that an absolute value of a value obtained by subtracting 1 from an ideal amplitude ratio, which indicates a ratio of an ideal amplitude of an eccentric component of the Y-photoconductor driving gear to an actual amplitude of an eccentric component of the M-photoconductor driving gear, is equal to or less than a maximum allowable amplitude ratio.

Abstract: An image forming apparatus includes a plurality of image bearing members, each of which is configured to bear a portion of a pattern image including a plurality of reference images in a given form, an endless moving member facing the plurality of image bearing members and configured to receive the pattern image, an image detecting unit configured to detect the plurality of reference images, a rotational angle detecting unit configured to separately detect each image bearing member at a given rotational angle, and a controller configured to detect a speed deviation pattern for each revolution of each image bearing member. The controller is configured to detect the speed deviation pattern based on a result obtained from a phase component and a quadrature component of a frequency signal generated from the detection result obtained by the rotational angle detecting unit and a result of detecting the plurality of reference images in the pattern image transferred onto the endless moving member.

Abstract: In an image forming apparatus, a rotation detector detects an angular velocity or an angular displacement of a shared drive motor, or an angular velocity or an angular displacement of a photosensitive element. A drive control unit executes a process for controlling a drive speed of a drive source of the photosensitive element based on a result of detection by the rotation detector.

Abstract: A multicolor imaging system includes a controller which adjusts a phase difference in rotations of photoreceptors based on information detected by a rotary position detector, and drive elements for photoreceptors which generate a velocity fluctuation in the same cycle as that of a transfer unit. The controller is configured to concurrently adjust the phases of the photoreceptors and those of the drive elements so that a registration error in four color toner image on an intermediate transfer belt is reduced to a minimum.

Abstract: An image forming apparatus includes a rotating member, a motor configured to rotate the rotating member, and a marking member having primary and secondary portions. The image forming apparatus also includes a mark sensor configured to detect the primary and secondary portions, and output a primary signal and a secondary signal, and a position sensor configured to determine a rotational position of the rotating member based on a primary reception time of one of the primary and secondary signals that comes immediately after the other of the primary and secondary signals when the position sensor receives the other of the primary and secondary signals at a start of a mark detecting operation. Further, the image forming apparatus includes a motor controller configured to control the motor based on the recognition result and make the rotational position consistent with a target position at a predetermined time during the mark detecting operation.

Abstract: A synchronized drive unit, including a drive member including a pulley; a driven member including a pulley; a relay member including to transmit a power; and timing belts hung around the drive and driven members through the relay member with tension and rotates the drive and driven members in synchronization, wherein each of the timing belts is formed of plural narrow timing belts parallely placed in a rotational axis direction of the pulley and the narrow timing belts are located on the driven member so as to counteract their eccentric components each other.

Abstract: An image forming apparatus includes a rotating member, a motor configured to rotate the rotating member, and a marking member having primary and secondary portions. The image forming apparatus also includes a mark sensor configured to detect the primary and secondary portions, and output a primary signal and a secondary signal, and a position sensor configured to determine a rotational position of the rotating member based on a primary reception time of one of the primary and secondary signals that comes immediately after the other of the primary and secondary signals when the position sensor receives the other of the primary and secondary signals at a start of a mark detecting operation. Further, the image forming apparatus includes a motor controller configured to control the motor based on the recognition result and make the rotational position consistent with a target position at a predetermined time during the mark detecting operation.

Abstract: A drive transmitter, including a first rotational axis transmitting a drive force of a drive source to a first rotator, a second rotational axis transmitting a drive force of the drive source to a second rotator, and an idler gear configured to transmit a drive force to the second rotational axis; wherein the first rotational axis penetrates the idler gear with a gap therebetween.

Abstract: A driving motor for a color black is shared between a photosensitive body for the color black and a driving roller that drives an intermediate transfer belt not shown. Furthermore, a driving motor for colors yellow, magenta, and cyan is shared between photosensitive bodies for the colors yellow, magenta, and cyan. Driving of the driving motor for the colors yellow, magenta, and cyan is controlled based on a first waveform as a speed fluctuation waveform of the photosensitive body for the color black obtained when the driving motor for the color black is driven at a predetermined speed and second waveforms as speed fluctuation waveforms of the photosensitive bodies for the colors yellow, magenta, and cyan obtained when the driving motor for the colors yellow, magenta, and cyan is driven at a predetermined speed.

Abstract: A drive transmission device that performs drive transmission through a plurality of systems and includes a first involute spline joint to perform drive transmission to a primary rotating body to be driven and a second involute spline joint to perform drive transmission to a secondary rotating body to be driven.

Abstract: An image forming system, in which a method of detecting a misregistration of a color image is performed, includes multiple image carriers, an optical writing unit, a transfer member extended by a drive roller and at least one driven roller, a rotation detector, a roller driving unit, a belt controller, an image detector configured to detect the images formed on the surface of the transfer member and obtain detection data, and a controller configured to calculate an amount of misregistration and correct relative misregistration of a scanning line between the image carriers based on a result of the calculation. In the image forming system, a distance from a transfer position to a detection position is an integer multiple of a travel distance of the transfer member during one revolution of the at least one driven roller.

Abstract: An image forming apparatus that includes a plurality of image bearing members, a plurality of drive sources each including a drive gear, a plurality of driven gears, a visible image forming unit, an endless traveling member, a transfer unit, an image detection unit, and a controller. The controller controls rotation of the plurality of image bearing members according to a velocity fluctuation pattern of each surface of the image bearing members based on a detection time interval between predetermined visible detection images formed on the surface of the image bearing member and transferred therefrom to the endless traveling member detected by the image detection unit. Each of the plurality of driven gears includes a gear portion and an engaging portion integrated therewith. The gear portion includes a geared circumference and the engaging portion engages the image bearing member.