Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Konica Corporation

Jun Onishi

Atsushi Takahashi

Masahito Takano

Takashi Fujiwara

Satoshi Ogata

Tadayuki Ueda

Toru Makino

Katsunori Takahashi

Hiroyuki Maruyama

Yumiko Izumiya

Taku Saito

Shinpei Kawasaki

Chohiko Fukuo

Kenji Tamaki

Kenji Izumiya

Eiji Nishikawa

Akinori Kimata

Akifumi Isobe

Masashi Sugano

Ryuji Okutomi

Shinobu Kishi

Naoto Tokutake

Takahiro Iwasaki

An image forming apparatus includes: a hardware processor that performs feedforward control on a motor; a driving roller that drives an intermediate transfer belt for transferring a toner image; a drive transmission system that transmits a driving force of the motor; a first detector that detects a speed of a driving shaft of the motor; a second detector that detects a speed of a driving shaft of the drive transmission system; and a storage that stores a plurality of sets of control data having different conformity states, wherein the plurality of sets of control data include pairs of a feedforward operation pattern and a drive transmission system deformation pattern, the drive transmission system deformation pattern corresponds to a fluctuation pattern of difference values, and the hardware processor compares the fluctuation pattern of difference values with the plurality of sets of control data.

Image forming apparatus and image forming program for reducing occurrences of color misregistration and density unevenness using fluctuation pattern of difference values

An image forming apparatus including: a photoreceptor drum; an intermediate transfer belt; a primary transferer; a secondary transferer, and a hardware processor which suppresses speed change of the intermediate transfer belt at a timing of the sheet entering the secondary transferer and at a timing of the sheet being ejected from the secondary transferer, wherein the hardware processor calculates speed changes of the intermediate transfer belt and the photoreceptor drum at the timing of the sheet entering the secondary transferer and at the timing of the sheet being ejected from the secondary transferer, and calculates a transmission rate between the intermediate transfer belt and the photoreceptor drum based on the calculated speed changes, and the hardware processor adjusts an operation amount of the driving roller based on the calculated transmission rate.

Image forming apparatus

An image forming apparatus includes: a driving roller that conveys a paper sheet; a detector that detects a desired point on the driving roller; and a hardware processor that: acquires a waveform signal indicating one of a change in an image forming position with respect to the paper sheet and a change in a sheet conveyance velocity; extracts a synchronous waveform signal from the waveform signal acquired by the hardware processor, the synchronous waveform signal being synchronized with one revolution of the driving roller, the one revolution being detected by the detector; and inputs a drive signal to a drive source of the driving roller, the drive signal being input to weaken an amplitude of the synchronous waveform signal extracted by the hardware processor.

Image forming apparatus and program compensating for eccentric components

An image forming apparatus includes: a photosensitive drum; a driving roller that drives a transfer member; a facing roller facing the driving roller; a driver that drives one of the photosensitive drum, the driving roller, and the facing roller; and a hardware processor that: acquires carry-in fluctuation information of speed fluctuation of any one of the photosensitive drum, the driving roller, and the facing roller when a sheet member is carried into the transfer member; detects carry-in fluctuation timing of the speed fluctuation of any one of the photosensitive drum, the driving roller, and the facing roller that occurs when the sheet member is carried into the transfer member; predicts carry-out fluctuation timing of speed fluctuation of any one of the photosensitive drum, the driving roller, and the facing roller that occurs when the sheet member is carried from the transfer member; and performs feedforward control on the driver.

Image forming apparatus and correction of speed fluctuation of a sheet member through the image formatting apparatus

A driving device includes: a first driving source; a second driving source; a first gear to which a driving force is transmitted from the first driving source; a second gear to which a driving force is transmitted from the second driving source; a third gear that engages with the first gear and the second gear; and a fixation shaft that pivotally supports the third gear, the fixation shaft being disposed such that a center of the fixation shaft, a rotation center of the first gear and a rotation center of the second gear are disposed on a straight line in which the fixation shaft is provided through the third gear; and a hole having a diameter for compensating eccentricity of the first gear, the second gear and the third gear is formed in the third gear.

Driving device, fixing device and image forming apparatus

An image forming apparatus includes an image carrier, an image carrier driver which rotates the image carrier, a rotation detector which detects rotation of the image carrier, a rotary member in contact with the image carrier, a rotary member driver which rotates the rotary member, a first controller which controls the rotary member driver, and a second controller. The second controller controls the image carrier driver based on an output of the rotation detector and also controls the image carrier driver in a manner which attenuates a fluctuation component at a specific frequency. When the first controller changes a surface velocity of the rotary member, the second controller controls the image carrier driver in a manner that attenuates a fluctuation component at a specific frequency related to the changed surface velocity of the rotary member.

Image forming apparatus for reducing influence of a rotary member's surface velocity change

An image forming apparatus includes: a first roller having an elastic part; a second roller configured to form a nip between the first roller and the second roller; a holding member configured to hold the second roller; and a control section configured to control the position of the holding member such that the center distance between the first roller and the second roller is maintained at a constant value when a sheet passes through the nip.

A belt tension adjustment mechanism provided on an inner side of an endless intermediate transfer belt and applying a tension to the intermediate transfer belt being rotated when a toner image is transferred on the intermediate transfer belt, said belt tension adjustment mechanism includes a holder having an opening section at one surface thereof; and an elastic member contained to be fixed in the holder while being compressed in a running direction of the intermediate transfer belt and having a convex section, wherein the convex section protrudes from the opening section of the holder toward a direction orthogonal to an image transfer surface of the intermediate transfer belt and is in direct contact with the intermediate transfer belt.

Belt tension adjustment mechanism and image forming apparatus

A sheet feeder device includes: a sheet feed tray configured to store a sheet stack formed with a plurality of paper sheets; an elastic member capable of expanding and contracting; a contact mechanism configured to bring the elastic member into contact with an edge of the sheet stack; an expansion mechanism configured to expand the elastic member in a direction of stacking of the paper sheets; and a control unit configured to cause the expansion mechanism to expand the elastic member while the elastic member is kept in contact with the edge of the sheet stack by the contact mechanism.

Sheet feeder device and image forming apparatus

An image forming apparatus includes upstream-side and downstream-side detection parts and a control section. The detection parts are disposed on a moving path of an intermediate transfer belt or a conveyor belt and detect a speed of the belt. The control section performs control to correct color misregistration of images composed of colors to be formed on the intermediate transfer belt or a recording medium conveyed by the conveyance belt on the basis of the detection result. The control unit calculates a difference between the speed detected by the upstream-side detection part and the speed detected by the downstream-side detection part after a predetermined time elapses since the upstream-side detection part detects the speed and performs the control on the basis of the difference. The predetermined time is obtained by dividing a distance between the detection parts by a target speed of the belt.

Image forming apparatus with color misregistration correction control

An improved image forming apparatus is described which can inhibit the quality of printed images from being degraded. A control unit performs a steering operation to shift an intermediate transfer belt toward a target belt position by controlling the inclination angle of a steering roller. Also, a memory stores the inclination angle of the steering roller in association with the operational states of rotary members facing the intermediate transfer belt. The control unit updates the values stored in the memory with an update value. When the result of detecting the belt edges indicate that the intermediate transfer belt falls in a predetermined range around the target belt position during the steering operation, the control unit determines the update value on the basis of the steering duration time and the inclination angle of the steering roller.

Image forming apparatus for controlling a steering operation of an intermediate transfer belt

An image forming apparatus including: a photoreceptor for bearing a toner image; a transfer body onto which the toner image borne by the photoreceptor is transferred; a drive section for driving the photoreceptor and transfer body respectively, and a control section for controlling the drive section so as to drive the photoreceptor and transfer body at a predetermined driving speed, wherein the control section, under a state in which the control section controls to drive the transfer body at the predetermined driving speed, controls to: a) drive the photoreceptor while changing the driving speed of the photoreceptor within a range of driving speeds between low speed and high speed, including the predetermined driving speed, b) extract torque characteristics under the control which includes the change of driving speed of the photoreceptor, and c) determine the driving speed of the photoreceptor based on the extracted torque characteristics.

An image forming apparatus including: an image bearing member for bearing a toner image; a transfer section, which is pressed against, and is separated from, the image bearing member, for transferring a toner image on the image bearing member onto a recording medium when being pressed against the image bearing member, a transfer section drive section for driving the transfer section to rotate; and a control section configured to control the transfer section drive section to carry out constant speed control and constant torque control, to drive said transfer section to rotate at a constant speed, and at a constant torque, respectively, wherein the control section carries out the constant torque control while the transfer section is pressed against the image bearing member, in accordance with a drive torque detected when the constant speed control is carried out while the transfer section is separated from the image bearing member.

Image forming apparatus and image forming method

An image forming apparatus includes a moving roller capable of axial movement; a medium end position detecting section for detection in the main scanning direction; and a control section for calculating the amount of misalignment of the medium from the detected end position; wherein the control section obtains the correction amount of the image forming position of the medium according to the amount of misalignment of the medium having been calculated, or the amount of misalignment of the medium and information of moving position of the roller, and provides control such that the medium or another medium coming later than the medium by a predetermined number of pages is moved by the moving roller by the difference between the correction amount of the image forming position and the amount of misalignment of the target medium, and the image forming position is corrected according to the correction amount.

A first mode to form a toner image of single color where a pressure contact release section T changes a primary transfer sectionto be in a pressure contact state, and a second mode to form an overlapped toner image where the pressure contact device T changes a plurality of the primary transfer sectionsto be in the pressure contact state can be executed, wherein a speed difference Dbetween an image carrierand an intermediate transfer beltin the first mode is controlled to be greater than a speed difference Dbetween the image carrierand the intermediate transfer beltin the second mode.

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Hino, Japan

Jun Onishi