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: 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 method, apparatus, and program for driving a motor in a feedback control system, capable of suppressing oscillation of the motor are disclosed. A motor drive controller includes a drive motor, a detector, and a motor drive controller. The drive motor drives a moving body around a target moving speed. The detector detects a current moving speed of the moving body and output it as a detector pulse signal. The controller calculates a difference between the current moving speed and the target moving speed, calculates a control value based on the difference, calculates a pulse rate of a drive pulse signal based on the control value after having controlled the control value to be within a predetermined value, and feedback controls the drive motor based on the pulse rate.

Abstract: A composite tube formed by covering an outer surface of a tube with a foam, characterized in that: the foam is formed of layers composed of bar-shaped foams; and in a section perpendicular to a longitudinal direction of the foam, each of 40% or more of the bar-shaped foams is formed as a substantially fan-shaped figure formed by long and short arc portions of two large and small concentric circles, respectively, and two linear portions extending radially toward an outer periphery from the center of the concentric circles, with the figure satisfying the condition of formula (1): 0.5<a/b<2.5 ??Formula (1) where a is a length corresponding to ½ of the sum of the lengths of the long arc portion and the short arc portion of a substantially fan-shaped figure, and b is the length of each of the linear portions of the substantially fan-shaped figure.

Abstract: Driving of a pulse motor is controlled in such a manner that a rotating body driven by the pulse motor rotates at a uniform angular velocity. Angular displacement of the rotating body is detected, a difference between a detection value of the angular displacement and a target value of angular displacement set in advance is calculated, and a drive pulse frequency of a drive pulse signal to be used for driving the pulse motor is calculated based on the difference and a reference drive pulse frequency. Whether the difference is added to the reference drive pulse can be selected.

Abstract: A transfer roller lies opposite to a supporting roller across an image carrying belt and abuts against the outer surface of the image carrying belt to form a transfer nip. A driving force transmission unit transmits driving force from a driving source to a driving roller. A drive control unit performs drive control of the driving source. A feedforward control unit performs feedforward control on the driving source via the drive control unit. An entry detecting unit detects entry of a sheet in the transfer nip. The feedforward control unit considers an entry detection signal output by the entry sensor as a trigger for performing feedforward control after a predetermined time.

Abstract: An image forming apparatus includes an image transfer belt, a first pressure member, a second pressure member, and an adjustable tension member. The image transfer belt is trained around multiple rollers for rotation along an endless belt travel path to convey an image for transfer to a recording sheet. The first pressure member is disposed on an outer surface of the image transfer belt. The second pressure member is disposed on an inner surface of the image transfer belt opposite the first pressure member. The first and second pressure members define an image transfer gap therebetween. The adjustable tension member is disposed on the image transfer belt adjacent the image transfer gap to adjust tension on the image transfer belt when the recording sheet enters and exits the image transfer gap.

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: 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 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: 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 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: An image-carrier driving unit drives an image carrier. An image forming unit forms an image on the image carrier. A moving-member driving unit drives a moving member that is movable towards and away from the image carrier. A detecting unit detects a position of the moving member at predetermined sampling times while the moving member is moving. A movement control unit performs a feedback control on the moving-member driving unit such that a detection result of the detecting unit follows a target value corresponding to each of the predetermined sampling times when the moving member moves while the image forming unit is forming the image on the image carrier.

Abstract: A sheet conveying device includes a torque estimation unit that, based upon a first load torque generated at a time that a sheet-like member passes through a first nip between a first driving roller and a first driven roller of an upstream sheet conveying unit, estimates a second load torque generated at a time that the sheet-like member passes through a second nip between a second driving roller and a second driven roller of a downstream sheet conveying unit; and a control unit that controls the driving torque such that the second load torque is counterbalanced by applying a counterbalancing torque in synchronization with a timing of entry of the sheet-like member into the second nip.

Abstract: A second rotary member is arranged opposite to a first rotary member to form a nip between them. A driving unit drives the first rotary member. A sheet-width measuring unit measures a width of a sheet to be fed into the nip. A speed compensating unit compensates a fluctuation of a rotation speed of the first rotary member occurring when the sheet is fed into the nip. The speed compensating unit adjusts a compensation target value for compensating the fluctuation of the rotation speed of the first rotary member based on the width of the sheet measured by the sheet-width measuring unit.

Abstract: In an image forming apparatus, a distance adjusting unit adjusts an inter-unit distance between a contact unit and an image carrier by moving the image carrier or the contact unit by applying an opposing force to the image carrier or the contact unit against a biasing force applied by a biasing unit based on thickness information of a recording sheet acquired by a thickness-information acquiring unit and data indicating a relationship between the thickness information and an inter-unit distance change amount stored in a data storage unit.

Abstract: Driving of a pulse motor is controlled in such a manner that a rotating body driven by the pulse motor rotates at a uniform angular velocity. Angular displacement of the rotating body is detected, a difference between a detection value of the angular displacement and a target value of angular displacement set in advance is calculated, and a drive pulse frequency of a drive pulse signal to be used for driving the pulse motor is calculated based on the difference and a reference drive pulse frequency. Whether the difference is added to the reference drive pulse can be selected.

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: A driving apparatus includes a driving unit, a driven unit driven by the driving unit, a driving control unit configured to control the driving unit by performing feed-forward control based on feed-forward target data determined in advance to reduce a speed change of the driven unit. The speed change of the driven unit is expressed substantially as a positive half cycle of a sinusoidal waveform having an amplitude and a time duration, and the feed-forward target data is calculated from the amplitude and the time duration to represent a rectangular waveform approximating the positive half cycle of the sinusoidal waveform.