Abstract: An imaging apparatus is disclosed that includes plural image carriers on which different-colored toner images are formed, the image carriers being driven and rotated to transfer the different-colored toner images onto one of an endless transfer member that is driven to rotate in contact with the image carriers or a transfer material that is carried by the endless transfer member. The imaging apparatus includes a phase calculating unit that extracts a periodic rotational variation component of each of the image carriers from a combination of periodic rotational variation components generated within said imaging apparatus and calculates a rotational phase of each of the image carriers based on the extracted periodic rotational variation component, and a rotational phase adjusting unit that adjusts a rotation stop phase of each of the image carriers based on the calculated rotational phase.

Abstract: A belt driving control device that includes a belt, a driving roller transmitting drive force to the belt, a belt phase detecting section detecting a phase of the belt, a correction amount computing section computing a correction amount of a belt travelling velocity corresponding to the detected phase of the belt for cancelling out fluctuation in the belt travelling velocity corresponding to the detected phase of the belt, and a storage section storing the correction amount of the belt travelling velocity corresponding to the detected phase of the belt. The belt driving control device further includes a driving control section retrieving the correction amount of the belt travelling velocity corresponding to the phase of the belt and controlling drive of the driving roller to cancel out the fluctuation in the belt travelling velocity based on the retrieved correction amount of the belt travelling velocity corresponding to the detected phase of the belt.

Abstract: A belt driving controller is disclosed. The belt driving controller executes driving control of a belt that is wound around plural sustaining rollers by controlling a driving sustaining roller that transmits driving force to the belt. The belt driving controller executes the driving control of the belt by controlling the driving sustaining roller so that a moving velocity fluctuation of the belt caused by a PLD (pitch line distance) fluctuation in the belt circumference direction becomes small, based on rotation information of rotation angle displacement or rotation angle velocities of two sustaining rollers in the plural sustaining rollers, in which two sustaining rollers, the diameters thereof are different from each other and/or the degrees to which the PLDs of parts of the belt which wind around the two sustaining rollers influence the belt moving velocity and the rotation angle velocities of the two sustaining rollers are different from each other.

Abstract: A control unit calculates a difference between a displacement of a belt detected by an encoder and a predetermined target value, calculates a pulse frequency of a driving pulse signal based on a feedback control based on the difference and a feed-forward control based on a reference driving pulse frequency, sets a control range of the feedback control to be equal to or smaller than a frequency of one rotation of a driven roller, and controls driving of a pulse motor such that the belt moves at a constant speed.

Abstract: A decelerator for reducing a speed of rotation of a drive source and transmitting drive of the drive source to an image bearing member of an image forming apparatus includes a drive shaft, a drive transmission member, and a pressure regulator. The drive shaft is rotated by the drive source. The drive transmission member is rotated by the drive shaft and includes a peripheral surface that contacts the drive shaft. The pressure regulator presses the drive shaft against a center of rotation of the drive transmission member and includes an alignment regulator to regulate alignment of the drive shaft in a direction of rotation of the drive transmission member. A drive device for rotating an image bearing member includes a drive source including a drive shaft, and the decelerator. An image forming apparatus includes the drive device and an image bearing member rotated by the drive device.

Abstract: An image forming apparatus is disclosed that includes an image carrier, a driving source, a rotation detection unit, and a control unit that performs fluctuation pattern recognition processing, control pattern construction processing, speed fine-adjustment processing, and remaining pattern recognition processing. The control unit is configured to perform control pattern correction processing for setting a frequency band of a remaining speed fluctuation to be detected by the remaining pattern recognition processing narrower than a frequency band of a speed fluctuation to be detected by the fluctuation pattern recognition processing and correcting the speed control pattern so as to be a pattern capable of reducing even the remaining speed fluctuation based on a remaining speed fluctuation pattern recognized by the remaining pattern recognition processing.

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: A belt drive control device includes: first and second detection devices which detect the angular displacement or velocity of a driven rotary member and the angular displacement or velocity of a drive rotary member, respectively; an extraction device which extracts, from the difference between the detection results of the first and second detection devices, the amplitude and phase of a variation component due to belt thickness variation; a control device which controls the rotation of the drive rotary member in accordance with the extracted amplitude and phase; first and second holding devices which hold the extracted amplitude and phase and normal ranges of the amplitude and phase, respectively; and first and second feedback devices which feed back the amplitude and phase to the rotation control, and performs feedback by using a substitution value for the amplitude or phase if the amplitude or phase is out of the normal range, respectively.

Abstract: An image forming apparatus includes a control unit to control a latent image support with a target rate; a first unit to detect patterns; plural parts to be detected revolving with the support; a second unit to detect passing of the part; a first generating unit to obtain an amplitude and a phase of fluctuation and a pattern for canceling out the fluctuation from the amplitude and the phase; a second generating unit to perform a process to obtain an amplitude and a phase of fluctuation while the support rotates once or more, perform the process again, calculate a change in the amplitude and phase, and generate another pattern for canceling out the change; and a correcting unit to correct the target rate by superimposing the patterns with the target rate.

Abstract: An image forming apparatus includes a latent image carrier having a moving surface on which a latent image is formed, a drive control mechanism to control a drive of the latent image carrier so as to match a rotation angular speed of the latent image carrier with a target rotation angular speed thereof, a surface moving member having a moving surface on which an adjustment pattern for use in controlling the drive of the latent image carrier is formed, an image forming mechanism to develop the latent image with toner and transfer a resultant toner image on the surface moving member so as to form the adjustment pattern along a surface moving direction thereof, a pattern sensor to detect the adjustment pattern, a correction mechanism to correct the target rotation angular speed of the latent image carrier based on an amplitude and a phase of a variable component in a pattern interval of the adjustment pattern detected with the pattern sensor.

Abstract: A belt drive control unit controls a rotation of belt supported by first and second rollers. Each of rotations of the first and second rollers are detected as first and second results. A rotation of the first roller is controlled in connection with thickness fluctuation in the belt using the first and second results. The belt drive control unit includes a sampling data acquisition unit, a correction value generator, a correction value storage, and a correction value reading controller. The sampling data acquisition unit obtains sampling data by sampling a difference value between the first and second results. The correction value generator generates correction value data for the belt based on the sampling data. The correction value storage stores the correction value data. The correction value reading controller reads the correction value data based on a rotation number of the belt to control a rotation of the first roller.

Abstract: A driving control device for use in an image forming apparatus includes a control unit that analyzes any one of a speed variation pattern and a thickness variation pattern of an endless belt member of the image forming apparatus per at least one rotation of the endless belt member while endlessly moving the endless belt member by a driving rotating unit, and starts to execute, based on a result of analysis, a driving-speed-control-pattern updating process to update a driving speed control pattern of the driving rotating unit per at least one rotation of the endless belt member, after a power of an image forming apparatus is turned on and within a preparation period in which a predetermined preparation process is completed so that an image forming operation can be started based on an image formation command from an operator.

Abstract: An image forming apparatus including an image carrying member, a transfer member, support rollers, a detecting mechanism, and a controller. The image carrying member supported by the support rollers, forms a toner image on its surface facing a surface of the transfer member, which transfers the toner image to a recording medium. The detecting mechanism includes a detection roller, a roller shaft, a moving member, and a sensor, and detects a speed of the image carrying member. The detection roller includes one support roller selected from the support rollers, and is provided with the roller shaft. The moving member is directly fixed to the roller shaft and rotates with the detection roller. The sensor detects a moving speed of the detection roller with the moving member. The controller controls a traveling speed of the image carrying member to a target speed based on a detection result of the sensor.

Abstract: A load torque variation upon entry or exit of a sheet into a nipping portion is reduced while a nipping force necessary for image formation is provided. An image transfer apparatus, an image fixing apparatus, or a registration apparatus comprises an opposite roller, a transfer roller, and a compression spring for pressing the opposite roller onto the transfer roller. A sheet of transfer material is transported into a nipping portion between the opposite roller and the transfer roller, where an image on the opposite roller is transferred to the transfer material. The apparatus includes a retaining unit configured to retain a certain distance between the first rotating body and the second rotating body as long as the thickness of the transfer material that passes through the nipping portion remains the same.

Abstract: A sheet conveying device, that can be included in an image forming apparatus, includes a drive source, a drive roller driven by the drive source, a driven roller to press against the drive roller and rotate with the drive roller, an angular velocity detector to detect an angular velocity of the drive roller, a timing estimation unit to estimate a timing when a sheet-type recording medium enters between the drive roller and the driven roller, and a controller to control the drive source based on detection results obtained by the angular velocity detector. The controller includes a feedback control unit to perform feedback control based on data obtained by the angular velocity detector, and a feed-forward control unit to perform feed-forward control based on data obtained by the timing estimation unit.

Abstract: A fluctuation detecting unit detects a fluctuation of an endless belt generated when a sheet is brought into contact with a predetermined position of the endless belt at an upstream side in a conveying direction from a nip portion based on fluctuation information acquired by a fluctuation information acquiring unit. An entry timing estimating unit estimates entry timing of the sheet into the nip portion based on a detection of the fluctuation. A correction control unit corrects a speed fluctuation of the endless belt generated when the sheet enters the nip portion by performing a feedforward control of a first driving unit based on the entry timing.

Abstract: An image forming apparatus includes a belt stretched across rollers and a resist rotary member that feeds out a recording medium on the belt. A correlation between a velocity of the belt and the resist rotary member is obtained. A target velocity of the belt or the resist rotary member, at which a difference between the velocity when the recording medium is in contact with both the belt and the resist rotary member and the velocity when the recording medium is not in contact with at least either the belt or the resist rotary member is minimum, is determined based on the correlation.

Abstract: A belt drive controlling device for controlling drive of an endless belt supported and driven by plural support rollers including a driving roller configured to drive the endless belt to rotate; and a driven roller which is rotated by the endless belt. The device performs arithmetic processing to extract one of two pieces of rotation variation information on two rollers of the support rollers, and perform controlling drive of the belt on the basis of the rotation variation information. A belt device including a belt, plural support rollers, a driving source, the belt drive controlling device, and a detector configured to detect rotation angular displacement or rotation angular velocity of two of the support rollers. An image forming apparatus including an image bearing member, a developing device and a transfer device, wherein the image bearing member and/or the transfer device includes the belt device.

Abstract: A sheet conveying device includes a pair of upstream rollers and a pair of downstream rollers each including a drive roller and a driven roller, a calculating unit, and a control unit. The upstream rollers include a measuring unit that obtains speed information of the upstream rollers. The calculating unit calculates a target value based on the speed information. The control unit controls the speed of the drive roller of the downstream rollers based on the target value.

Abstract: A motor control device includes a pair of rotating members, a driving motor, and a timer-controller. The pair of rotating members nips and conveys a recording medium. The driving motor drives at least one rotating member of the pair of rotating members. The timer-controller calculates a time at which the recording medium passes through a nip formed by the pair of rotating members and controls the driving motor by correcting an excitation time of the driving motor near the time at which the recording medium passes through the nip formed by the pair of rotating members.