An image-forming device has a plurality of cylindrical image-carrying members, and an optical scanning unit. The plurality of cylindrical image-carrying members is provided in a main casing for rotating about respective rotational axes. The rotational axes are parallel to one another and juxtaposed in a single direction. The optical scanning unit is provided in the main casing and has a plurality of laser generators, a single rotatable polygon mirror, a plurality of mirrors, and a plurality of lenses. The plurality of laser generators is provided one-to-one relationship to the plurality of image-carrying members to emit respective laser beams. The single rotatable polygon mirror deflects the respective laser beams to scan the respective image-carrying members therewith. The plurality of mirrors is provided one-to-one relationship to the plurality of image-carrying members to guide the respective laser beams along respective optical paths to the respective image-carrying members. The plurality of lenses is provided one-to-one relationship to the plurality of image-carrying members and provided in the respective optical paths and between the respective mirrors and the respective image-carrying members. Distances from the respective mirrors to the respective image-carrying members being equal to one another.

Image-forming device

A rotational speed of a first roller and a time required for a second roller to make one rotation are measured. A controller calculates an amplitude and a phase of fluctuation in a rotational speed in one rotation period of the first roller while the first roller is rotated by a predefined angle based on the speed and the time. The controller corrects measured speed of the first roller based on the amplitude and the phase, and controls a driving roller based on corrected speed.

Belt drive control method, belt-drive control device, and image forming apparatus

A belt drive control device of the present invention is constructed to sense the angular displacement or the angular velocity of a driven roller, separates from the angular displacement or the angular velocity sensed an AC component having a frequency that corresponds to the periodic thickness variation of an endless belt in the circumferential direction, and then controls the rotation of a drive roller in accordance with the amplitude and phase of the AC component.

Belt drive control device and image forming apparatus including the same

A belt drive controller for controlling each belt stopping position with high accuracy during intermittent movement of a belt. This belt drive controller controls driving of a belt to intermittently move a belt wrapped around a plurality of supporting rollers including a driven roller and a drive roller. This controller detects a rotation angular displacement or a rotation angular velocity of two supporting rollers having mutually different diameters, and controls driving of the drive roller based on the detected rotation data so that the position of the belt in the direction of movement becomes a predetermined target position.

Belt drive controller and image forming apparatus provided with same

A belt driving control apparatus which realizes high-precision belt driving by specifying with high precision the pitch line distance (PLD) that affects the belt movement speed. This belt driving control apparatus controls the driving of the belt by controlling the rotation of driving supporting rotating bodies via which the rotational driving force is transmitted, among the plurality of supporting rotating bodies on which the belt is installed. This control apparatus controls the rotation of the driving supporting rotating bodies on the basis of rotation information relating to the rotational angular displacement or rotational angular speed in two supporting rotating bodies among the plurality of supporting rotating bodies which have different diameters, or in which the degree to which the PLD of the portion of the belt that is wound on each of these supporting rotating bodies affects the relationship between the movement speed of the belt and the rotational angular speed of each of these supporting rotating bodies is different, so that the fluctuation in the movement speed of the belt that is generated by the fluctuation in the PLD in the circumferential direction of the belt is reduced.

Belt driving control apparatus, belt apparatus and image forming apparatus

PROBLEM TO BE SOLVED: To provide a belt drive control method and its device in which a belt is driven at a constant moving speed without being affected by the fluctuation in the thickness of the belt while increase in the cost is suppressed, to provide a belt device, a process cartridge, an image forming device, a program and a recording medium. SOLUTION: Detection is made for rotational angular displacement or rotational angular velocity of a follower roller 502, alternating components in the rotational angular velocity having the frequency corresponding to the periodic thickness fluctuation along the peripheral direction of a belt 500 are extracted based on the detection results and rotation of a driving roller 501 is controlled based on the amplitude and the phase of the alternating components. COPYRIGHT: (C)2005,JPO&NCIPI

Belt drive control method and its device, belt device, image forming device, process cartridge, program, and recording medium

PROBLEM TO BE SOLVED: To provide a method and a device for driving and controlling a rotating body, by which the fluctuations of a rotational speed in a single rotational period of a photoreceptor drum caused by the eccentricity or the like of a gear can be suppressed, without using a high accuracy rotary encoder which becomes a causes for increase in cost. SOLUTION: The method for driving and controlling the rotation which controls the rotation of the photoreceptor drum is constituted as follows. The displacement of a rotation angle or a rotational angular speed of a rotating shaft of a motor, which generates a rotational driving force transmitted to the photoreceptor drum via the gear, is detected. The motor is controlled on the basis of the detection result. Accordingly, the rotation of the photoreceptor drum can be controlled. The motor is controlled by two or more kinds of control patterns whose driving conditions are mutually different. The rotation time, when the photoreceptor drum is rotated at a predetermined rotation angle during controlling by each control pattern, is measured. The amplitude and the phase of the fluctuation in the rotational speed in a single rotational period of the photoreceptor drum is obtained, on the basis of the measurement result of each rotation time. The motor is controlled, on the basis of the amplitude and the phase of the fluctuation of the rotational speed. COPYRIGHT: (C)2005,JPO&NCIPI

Koide Hiroshi

Papers

Belt drive control method and its device, belt device, image forming device, process cartridge, program, and recording medium

Method and device for driving and controlling rotating body, image forming apparatus, process cartridge, program, and recording medium