Ricoh Company, Ltd.

Haruyuki Suzuki

Takuya Murata

Tomohiko Kamatani

Fumihiro Shimizu

Katsuhisa Furuse

Norihiro Yamamoto

Mitsuo Suzuki

Kei Hagiwara

Takashi Hashimoto

Takahisa Koike

Toshihiro Shigemori

Masaki Satoh

Takeo Seki

Eiki Yoshimizu

Hiroyuki Kiguchi

Masayuki Muranaka

A permanent magnet motor is provided, which includes a rotor including a rotation axle and a plurality of magnetized rotor magnets on a periphery, which rotor magnets are magnetized to form alternately N-poles and S-poles; first and second ring-shaped-claw-pole units, whose inner circumferences face the rotor magnets, including a plurality of first and second claw-poles along the inner circumference, the first and the second claw-poles being closely adjacent to each other extending alternately in upward and downward axis directions of the rotation axle, bottom sides of the first and the second claw-poles forming a ring shape. A first opening portion is formed in a first joint surface of the first ring-shaped-claw-pole unit, to be joined to the second ring-shaped-claw-pole unit, and the second opening portion is formed in a second joint surface of the second ring-shaped-claw-pole unit, to be joined to the first ring-shaped-claw-pole unit.

Permanent magnet motor, position estimation apparatus and motor drive control apparatus

A current detecting device includes: a drive signal generating unit configured to generate a control signal based on a control voltage value indicating drive force to be applied to a target; a current detecting unit configured to detect a current value output based on the control signal generated by the drive signal generating unit; and a correction unit configured to correct the current value detected by the current detecting unit, based on at least a magnitude of the control voltage value.

Current detecting device, motor controlling system, image forming apparatus, sheet conveying device, robot, and current detecting method

A motor controller that controls a motor in a first control method based on a first current command value and a second control method based on a second current command value. The motor controller includes an analog-to-digital converter to generate the second current command value based on a reference signal externally input to the motor controller and a current limit generator to generate an upper limit value of the first current command value based on the second current command value.

Motor controller, motor driving apparatus, motor driving system, image forming apparatus, and conveying device

A novel motor controller controls a stepping motor and includes a command value calculator to calculate and output a speed command value and an angle command value based on a reference clock. A control method selector is included to select one of the open-loop control and the closed-loop control in accordance with the speed command value. A command value output unit is included to output a first target value as the first current command value when the open-loop control is selected and outputs a second target value as the second current command value when the closed-loop control is selected. The motor controller controls the stepping motor based on the first target value when the open-loop control is selected and the second target value when the closed-loop control is selected.

Motor controller, motor driver, and motor driving system

A motor driving apparatus for causing drive current to flow in first and second armature coils of two-phases to rotate a rotator, includes a drive unit configured to give first and second PWM pulse signals to ends of the first and second armature coils. The drive unit includes a first shift unit configured to, when a difference between pulse widths of the first PWM pulse signals given to the ends of the first armature coil is less than or equal to a first predetermined value, shift forward any one of pulses of the first PWM pulse signals, and a second shift unit configured to, when a difference between pulse widths of the second PWM pulse signals given to the ends of the second armature coil is less than or equal to a second predetermined value, shift backward any one of pulses of the second PWM pulse signals.

Motor driving apparatus, motor control apparatus, conveyance apparatus and motor driving method

A motor control apparatus includes: a driving control unit that performs driving control of a motor in accordance with a drive command; an interrupt control unit that starts and executes interrupt processing for performing the driving control at an interrupt cycle; a first processing unit that executes same first processing every time the interrupt processing starts; and a second processing unit that selects and executes a different piece of processing from second processing every time the interrupt processing starts. The interrupt control unit executes at least one piece of the first processing before executing the second processing in the interrupt processing.

Motor control apparatus and motor control method

A motor controller receiving as input an encoder signal changing in response to a driving position of a motor, outputting a motor driving command in response to the encoder signal to control at least one of the driving position or a driving velocity of the motor, includes an interrupt processing section to execute interrupt operations every prescribed interrupt cycle, a low-frequency processing section to selectively execute a subset of the interrupt operations every prescribed number of the interrupt cycles, and a high-frequency processing section to execute another subset of the interrupt operations every prescribed interrupt cycle, wherein the high-frequency processing section executes at least an operation to detect the driving position indicated by the encoder signal, wherein the low-frequency processing section executes at least an operation to generate the motor driving command.

Motor controller and motor control method

A motor control device controls a speed of a motor. The motor control device includes: a target speed generating unit that generates a target speed; a speed detecting unit that detects a current speed of the motor; a speed comparing unit that compares the target speed with the current speed to calculate a speed error; an error amplifying unit that amplifies the speed error and outputs a control value; and a motor driving unit that drives the motor in accordance with the control value. The error amplifying unit has proportional integral characteristics by which the speed error is amplified with a proportional gain and integration is performed in a lower frequency range than an integral corner frequency, increases the proportional gain as the current speed is higher, and shifts the integral corner frequency to a lower frequency as the current speed is higher.

Motor control device

A motor speed controller controls a motor speed to generate a phase reference pulse; generates a FG pulse per rotary angle of the motor; detects a difference between the number of phase reference pulses and the number of FG pulses for output as an integer number phase difference; detects and measures a time difference between an edge of the phase-reference pulse and an edge of the FG pulse in units of the reference clock for output as a decimal fraction phase difference; adds the integer number phase difference to the decimal fraction phase difference at a predetermined ratio for output as a phase difference; and controls driving of the motor in accordance with the phase difference.

Motor speed controller and control method

A motor drive controller to control a motor via multiple sensors includes a first phase detector to compare respective differential pairs of the sensor signals from the same sensor to detect phases of the rotor, and output a first phase information signal; a second phase detector to compare a respective one of the multiple sensor signals with another sensor signal from the different sensor to detect the phases and output a second phase information signal; a phase divider to divide the phases, detected by the first and second phase detectors, into multiple predetermined phase intervals; a signal selector to select one of the multiple sensor signals in the multiple predetermined phase intervals; and a third phase detector to detect whether the signal selected by the signal selector reaches a predetermined threshold level corresponding to a predetermined phase of the rotor, and output a third phase information signal.

Motor drive controller and control method

A motor drive controller to drive a motor, based on multiple sensors that generates multiple sensor signals corresponding to different positions of the rotor; including a first phase detector to compare a respective one of the multiple sensor signals with a paired sensor signal from the same sensor to detect phases of the rotor, and output a first phase information signal representing a first detected phase; a phase divider to divide the phases, detected by the first phase detector into multiple predetermined phase intervals; a signal selector to select one of the respective multiple sensor signals from the multiple sensors in the multiple predetermined phase interval; and a second phase detector to detect whether the signal selected by the signal selector reaches a predetermined threshold level corresponding to a predetermined phase of the rotor, and output a second phase information signal representing a second detected phase.

Disclosed is an angle detection device including plural sensors that output corresponding sinusoidal signals, wherein each of the sinusoidal signals varies sinusoidally depending on a rotational angle of a rotor of a motor, and each of the sinusoidal signals has a phase that depends on a position of the corresponding sensor; a vector generating unit that generates a vector represented by a result of mutually operating at least two of the sinusoidal signals; a vector rotation unit that rotates the vector by operating the vector and reference sine waves having corresponding phases; and an angle search unit that causes the vector rotation unit to sequentially rotate the vector until a phase of the vector becomes a predetermined phase, and that detects an angle between the vector prior to being rotated and the predetermined phase as the rotational angle of the rotor of the motor.

Angle detection device, motor driving device, and image forming apparatus

An image forming apparatus includes an optical scanning unit, a measurement unit, a first adjustment unit and a second adjustment unit. The optical scanning unit includes a plurality of light sources to emit laser beams, a single oscillating mirror deflector to deflect the laser beams used for scan processing in a main scanning direction, and a scan-focusing member to focus the deflected laser beams onto a plurality of photoconductors. The measurement unit measures a resonance frequency of the oscillating mirror deflector. The first adjustment unit adjusts a speed of the photoconductors in a sub-scanning direction. The second adjustment unit adjusts a magnification ratio of image data in the sub-scanning direction. The first adjustment unit and the second adjustment unit adjust the image magnification ratio of image data in the sub-scanning direction depending on the resonance frequency as measured by the measurement unit.

Image forming apparatus

A motor driving device driving coil terminals of a three-phase motor to flow three-phase currents includes: a pulse modulator generating three-phase modulation pulses, each of which has a duty ratio in accordance with a voltage level of a coil terminal; a shift amount selection unit selecting a first shift amount corresponding to at least one of two predetermined amounts according to a pulse width of the longest pulse among the three-phase modulation pulses; a first shift unit shifting the second-longest pulse among the three-phase modulation pulses backward by the first shift amount to delay timing; a second shift unit shifting the third-longest pulse among the three-phase modulation pulses backward by a predetermined second shift amount to delay timing; and an inverter driving each of the coil terminals by switching a driving power supply with the three-phase modulation pulses by reflecting shift results of the first and second shift units.

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Kanagawa, Japan

Haruyuki Suzuki