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

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of more accurately calculating the rate of elongation and contraction of recording paper regardless of irregularity in the conveying speed of the recording paper and an image forming state on the recording paper, and to provide its control method. SOLUTION: The image forming apparatus performs such image forming operation that a toner image formed on a photoreceptor drum 505 is transferred and fixed on the same recording paper by two or more times, and has: two or more area sensors 101, 102 and 103 detecting the position of the recording paper; a size calculation part 401 calculating the size of the recording paper before fixing as first recording paper size and that after fixing as second recording paper size based on the result of detection by the area sensors 101, 102 and 103; and a control part 400 calculating the rate of elongation and contraction of the recording paper before and after fixing from the first and the second recording paper sizes and controlling the image forming operation based on the rate of elongation and contraction. COPYRIGHT: (C)2008,JPO&INPIT

Image forming apparatus and its control method

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

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

A drive control device for a brushless motor having a rotor and a plurality of coils with different phases can be included in an image reading apparatus or an image forming apparatus. The drive control device may include a detection target configured to rotate in synchronization with rotation of the rotor and having formed thereon a pattern representing modulation information, a detector configured to read the pattern and to output modulated output signals, a demodulator configured to demodulate the modulated output signals and to obtain demodulated information, and a controller configured to control rotation of the rotor on the basis of at least the demodulated information obtained by the demodulator.

Brushless-motor driving control device, image reading apparatus, and image forming apparatus

PROBLEM TO BE SOLVED: To provide a drive device and image forming apparatus, capable of preventing the speed variation of a rotor from being deteriorated due to torsional vibration of a rotating shaft and making the apparatus inexpensive. SOLUTION: A planetary mechanism 200Y is provided on the drive side of a photoreceptor 1Y and on the opposite side (on this side of the apparatus), and a fly wheel 106Y is provided at the tip of an output shaft 203Y extended from the planetary mechanism 200. An outer ring part 201Y of the planetary mechanism 200Y is formed on the flange on this die of the photoreceptor 1Y. An output shaft 203Y as a sun part of the planetary mechanism 200Y is rotatably supported on a first side plate 111 at this side and a second side plate 112 at this side through a bearing 113. Three planetary gears 202a, 202b, 202c are rotatably fixed to a planetary shaft provided on the first side plate 111Y at this side. The output shaft 203Y, the planetary gears 202aY, 202bY, 202cY and the outer ring part 201Y are configured to approach and separate each other. COPYRIGHT: (C)2010,JPO&INPIT

Drive device and image forming apparatus

PROBLEM TO BE SOLVED: To provide a planetary gear type reduction gear capable of relaxing the fluctuation of rotating angular velocity and vibration by relaxing uneven application of load to a plurality of planetary gears provided in a planetary gear type speed reducing mechanism, and capable of prolonging service life of a gear, and to provide an image forming device. SOLUTION: At least one of a first planetary gear part 19 and a second planetary gear part 20 structuring a stepped planetary gear 29 is structured of a helical gear. The helical gear is structured to generate a thrust load, which is to be generated by engaging the stepped planetary gear 29 with both of a first gear 11 and a second gear 13, in one direction of a rotary shaft direction of the stepped planetary gear 29. The stepped planetary gear 29 is supported freely to move in the rotary shaft direction in response to the thrust load, and a carrier 23 has a transmitting means, which receives the thrust load generated in one of the stepped planetary gears 20 and transmits the thrust load in the opposite direction to other stepped planetary gear. COPYRIGHT: (C)2010,JPO&INPIT

Planetary gear type reduction gear and image forming device

PROBLEM TO BE SOLVED: To provide a drive control method which enables highly precise conformal speed drive control wherein an error of angular displacement of a rotor is not increased cumulatively, and an apparatus or the like for the method. SOLUTION: The angular displacement of the rotor driven by using a pulse motor is detected. A difference between a detected value P(i-1) of the angular displacement and a target value Ref(i) of previously set angular displacement is obtained. A driving pulse frequency u(i) of a driving pulse signal which is used for driving the pulse motor is obtained based on a standard driving pulse frequency Refp - c and the difference between the detected value P(i-1) and the target value Ref(i). The pulse motor is driven by a driving pulse signal having the driving pulse frequency u(i), so that the rotor is rotated by a conformal speed. COPYRIGHT: (C)2004,JPO&NCIPI

Komatsu Makoto

Papers

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

Brushless-motor driving control device, image reading apparatus, and image forming apparatus

Drive device and image forming apparatus

Planetary gear type reduction gear and image forming device

Drive control method and its apparatus, belt device, image forming apparatus, image reading apparatus, program, and record medium