Abstract: A sheet processing device includes a sheet processing unit that is moved to perform sheet processing on a sheet; a sheet-processing moving unit that moves the sheet processing unit; a drive-mode determining unit that determines a drive mode of the sheet-processing moving unit; and a drive control unit that drives the sheet-processing moving unit in accordance with the drive mode. The drive-mode determining unit determines the drive mode such that the sheet processing unit is moved at combination acceleration that is a combination of first acceleration and second acceleration with a shift of time that is determined based on the cycle of the natural vibration that occurs during acceleration of the sheet processing unit.

Abstract: A sheet processing device includes a sheet processing unit that is moved to perform sheet processing on a sheet; a sheet-processing moving unit that moves the sheet processing unit; a drive-mode determining unit that determines a drive mode of the sheet-processing moving unit; and a drive control unit that drives the sheet-processing moving unit in accordance with the drive mode. The drive-mode determining unit determines the drive mode such that the sheet processing unit is moved at combination acceleration that is a combination of first acceleration and second acceleration with a shift of time that is determined based on the cycle of the natural vibration that occurs during acceleration of the sheet processing unit.

Abstract: An image forming apparatus includes an image forming unit configured to form an image; a drawer unit configured to be pulled out from a body of the image forming apparatus; a first lock unit configured to receive power from a power supply and perform at least one of lock and unlock of the drawer unit with respect to the body; and a second lock unit configured to perform lock and unlock of the drawer unit with respect to the body by a mechanical operation performed by an operator.

Abstract: The image forming apparatus includes an image forming section; a conveyance path to convey a recording medium to the image forming section; a drawer unit including the conveyance path and configured to be pulled out relative to the apparatus; an electrical cable to electrically connect the drawer unit and an interior of the apparatus even when the drawer unit is pulled out from the apparatus; and a cable holder (a first regulating member) to ensure that that the cable is securely prevented from protruding from the drawer unit. According to the present invention, the electric cable is prevented from running off from the drawer unit due to the folding of the cable caused by the regulating member, so that the electric cable is prevented from getting hung up on the parts disposed in the body.

Abstract: An image forming apparatus having a drawer unit that includes therein a paper-feeding conveying path for conveying a recording medium conveyed from a paper feeding unit on which the recording media are stacked to an image forming unit and/or a discharge conveying path for conveying the recording medium on which an image has been formed to a discharging unit, and be drawn out from an apparatus main body; a lock unit that locks the drawer unit to the apparatus main body; a straddle detecting unit that detects whether the recording medium straddles a conveying path in the apparatus main body and a conveying path in the drawer unit; and a controller that controls the lock unit to lock the drawer unit to the apparatus main body when the straddle detecting unit detects the straddle.

Abstract: An image forming apparatus includes a drawer unit configured to be drawn out from a body of the image forming apparatus. The drawer unit includes a carriage path for carrying a recording medium, a lock unit configured to lock the drawer unit in the body, a driving unit configured to drive the lock unit, the driving unit including at least a driving source, and a drawer unit cover configured to cover at least the drawer unit. The drawer unit cover is a part of an outer cover of the body arranged on a side in a drawing direction of the drawer unit. The drawer unit cover is attached to the drawer unit so that the drawer unit cover is removed from the drawer unit in a state where the drawer unit is attached to the body.

Abstract: An image forming apparatus includes a drawer unit configured to be drawn out from a body of the image forming apparatus. The drawer unit includes a carriage path for carrying a recording medium, a lock unit configured to lock the drawer unit in the body, a driving unit configured to drive the lock unit, the driving unit including at least a driving source, and a drawer unit cover configured to cover at least the drawer unit. The drawer unit cover is a part of an outer cover of the body arranged on a side in a drawing direction of the drawer unit. The drawer unit cover is attached to the drawer unit so that the drawer unit cover is removed from the drawer unit in a state where the drawer unit is attached to the body.

Abstract: An image forming apparatus includes an image forming unit configured to form an image; a drawer unit configured to be pulled out from a body of the image forming apparatus; a first lock unit configured to receive power from a power supply and perform at least one of lock and unlock of the drawer unit with respect to the body; and a second lock unit configured to perform lock and unlock of the drawer unit with respect to the body by a mechanical operation performed by an operator.

Abstract: The present invention is concerning to an image forming apparatus comprising: a drawer unit that includes therein a paper-feeding conveying path for conveying a recording medium conveyed from a paper feeding unit on which the recording mediums are stacked to an image forming unit and/or a discharge conveying path for conveying the recording medium on which an image has been formed to a discharging unit, and be drawn out from an apparatus main body; a lock unit that locks the drawer unit to the apparatus main body; a straddle detecting unit that detects whether the recording medium straddles a conveying path in the apparatus main body and a conveying path in the drawer unit; and a controller that controls the lock unit to lock the drawer unit to the apparatus main body when the straddle detecting unit detects the straddle.

Abstract: The image forming apparatus includes an image forming section; a conveyance path to convey a recording medium to the image forming section; a drawer unit including the conveyance path and configured to be pulled out relative to the apparatus; an electrical cable to electrically connect the drawer unit and an interior of the apparatus even when the drawer unit is pulled out from the apparatus; and a cable holder (a first regulating member) to ensure that that the cable is securely prevented from protruding from the drawer unit. According to the present invention, the electric cable is prevented from running off from the drawer unit due to the folding of the cable caused by the regulating member, so that the electric cable is prevented from getting hung up on the parts disposed in the body.

Abstract: An image forming apparatus includes a recording medium transport belt which is suspended by a plurality of roller members. An image is secondarily transferred from a first image carrier through an intermediate transfer body to a recording medium. An image is directly transferred from a second image carrier to the recording medium. The image forming apparatus further includes a pattern image sensing unit which senses a pattern image transferred from the first image carrier and the second image carrier finally to the recording medium transport belt. Each of a distance from a secondary transfer position to a sensing position and a distance from a direct transfer position to the sensing position in a recording medium transport belt rotation direction is a natural number times a circumferential length of a roller member causing a speed change in the recording medium transport belt among the plurality of roller members.

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: 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: An image forming apparatus includes a primary transfer device that primarily transfers a first image from a first image bearer onto a first belt unit at a primary transfer position, a secondary transfer device that secondarily transfers the first image from the first belt unit onto a printing medium at a secondary transfer position, and a direct transfer device that directly transfers a second image from a second image bearer onto the printing medium at a direct transfer position. A second belt unit is rotatably suspended by plural second rollers and carries and conveys the printing medium through the direct transfer position and the secondary transfer position. An interval between the direct transfer position and the secondary transfer position is prescribed natural number times of a circumference of one of the plural second rollers, which fluctuates a velocity of the second belt unit.

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: 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 rotary drive device includes a motor including a rotary shaft, a planetary gear mechanism, and a rotation position detector. The planetary gear mechanism decelerates a rotation output of the motor at a reference reduction ratio and includes an outer gear, multistage gears, and an output shaft. The outer gear is fixed to a housing of the motor. The multistage gears are provided inside the outer gear. The output shaft transmits the decelerated rotation output of the motor to an outside of the rotary drive device. The rotation position detector detects a rotation position of the output shaft to control rotation of the motor. The motor, the planetary gear mechanism, and the rotation position detector are combined into a single integrated unit and aligned in an axial direction of the rotary shaft of the motor.

Abstract: A driving-force transmitting member is formed of a material having a linear expansion coefficient larger than that of a sleeve bearing, and ?x1>r1×?t×a?R1×?t×b is satisfied, where R1 is inner radius of the sleeve bearing, r1 is outer radius of a rotary shaft unit, ?x1 is difference between the inner radius R1 and the outer radius r1 at a reference temperature, ?t is maximum amount of temperature change of the driving-force transmitting member relative to the reference temperature, a is linear expansion coefficient of the sleeve bearing, and b is linear expansion coefficient of the driving-force transmitting member.

Abstract: In an image forming apparatus, during a rotation of an intermediate transfer belt performed after a contact-state-changing rotation in which the number of photoconductors contacting the intermediate transfer belt has changed, a control unit of a belt driving device controls the driving speed of a belt driving motor based on a period of the intermediate transfer belt determined in the rotation immediately before the contact-state-changing rotation instead of a period determined in the contact-state-changing rotation.

Abstract: An image forming apparatus includes a recording medium transport belt which is suspended by a plurality of roller members. An image is secondarily transferred from a first image carrier through an intermediate transfer body to a recording medium. An image is directly transferred from a second image carrier to the recording medium. The image forming apparatus further includes a pattern image sensing unit which senses a pattern image transferred from the first image carrier and the second image carrier finally to the recording medium transport belt. Each of a distance from a secondary transfer position to a sensing position and a distance from a direct transfer position to the sensing position in a recording medium transport belt rotation direction is a natural number times a circumferential length of a roller member causing a speed change in the recording medium transport belt among the plurality of roller members.