| Patent application number | Description | Published |
|---|
| 20080232880 | Sheet conveying device and image forming apparatus - 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. | 09-25-2008 |
| 20080303202 | SHEET CONVEYING DEVICE AND IMAGE FORMING APPARATUS - 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. | 12-11-2008 |
| 20090060613 | Image transfer apparatus, image fixing apparatus, and registration apparatus - 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. | 03-05-2009 |
| 20090169225 | Driving control device and image forming apparatus including the same - 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. | 07-02-2009 |
| 20090238588 | Image forming apparatus - 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. | 09-24-2009 |
| 20090263158 | Belt driving device and image forming apparatus - 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. | 10-22-2009 |
| 20090322020 | Decelerator, drive device including same, and image forming apparatus incorporating the drive device - 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. | 12-31-2009 |
| 20090324262 | Image forming apparatus - 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. | 12-31-2009 |
| 20100017019 | BELT-CONVEYANCE CONTROL DEVICE, IMAGE FORMING APPARATUS, BELT-CONVEYANCE CONTROL METHOD, AND COMPUTER PROGRAM PRODUCT - 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. | 01-21-2010 |
| 20100082163 | Belt driving control device, belt driving control method, and image forming apparatus - 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. | 04-01-2010 |
