Ricoh Company, Ltd.

Katsuhisa Furuse

Tomohiko Kamatani

Haruyuki Suzuki

Fumihiro Shimizu

Yasuhiro Ishizaka

Masanobu Fukushima

Shohtaroh Sohma

Shinichi Kojima

Koichi Hagino

Shinichiro Yamada

Toshiya Murota

Senta Sekido

An angle detecting device, generating phase information for indicating phases corresponding to rotational positions of a rotor of a motor, comprises an intersection detecting unit, configured to detect timing at which paired sensor signals intersect with each other, and to detect points of intersection; an intersection level detecting unit configured to detect intersection levels that are amplitude levels of the sensor signals, based on the timing at which the respective pairs of the sensor signals intersect with each other; an intersection level adjusting unit configured to adjust the detected intersection levels of the sensor signals to a certain amplitude level, and to output a successively selected one of the adjusted sensor signals as an intersection level adjustment signal; and a phase information detecting unit configured to generate detection results indicative of whether the intersection level adjustment signal is greater than respective threshold levels corresponding to the phases, thereby generating the phase information responsive to the detection results.

Angle detecting device, motor drive controlling device, motor device and method of controlling an angle detecting device

An angle detector includes an intersection phase detector to compare each pair of multiple sensor signals or multiple sensor processed signals generate and output each intersection phase detection signal indicating a phase at which the signal level difference of the each pair is a first maximum hysteresis error after signal levels of signals of the each pair match, an intersection level detector to detect each intersection level and generate and output multiple intersection level signals indicating the detected intersection level, a signal selector to single out a selection signal of the either of the multiple sensor signals or the multiple sensor processed signals; a phase detector to detect that a signal level of the selection signal selected by the signal selector has reached a threshold level and a threshold level adjuster to adjust the threshold level based on the intersection level signal and the first maximum hysteresis error.

Angle detector, motor drive controller, and motor device

An angle detector includes a first signal level detector to detect a sensor processed signal having a maximum signal level of a first set of sensor processed signals obtained by signal processing of multiple sensor signals, each of the multiple sensor signals having a signal level corresponding to a rotational position of a rotor of a motor having multiple coils, a signal level adjuster to adjust each signal level of the first set of the sensor processed signals to match the sensor processed signal having a maximum signal level with a first adjustment level, a signal selector to single out a selection signal from a second set of sensor processed signals adjusted by the signal level adjuster, and a phase detector to output a phase information signal in which the signal level of selection signal selected by the signal selector corresponds to a phase of the rotor.

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

Disclosed is a semiconductor laser driving unit that outputs a driving current for driving a semiconductor laser. A value of a correction current is set in such a manner as to determine a rising characteristic and/or a falling characteristic of an output of the driving current in accordance with a value of the driving current.

Semiconductor laser driving unit, optical scanner having semiconductor laser driving unit, and image forming apparatus

A switching power supply circuit includes a plurality of switching regulators and a timing adjustment circuit. The plurality of switching regulators converts an input voltage input to an input terminal into a plurality of predetermined constant voltages, and outputs the plurality of predetermined constant voltages from a plurality of output terminals, respectively. The timing adjustment circuit adjusts phases of a plurality of pulse signals generated by the plurality of switching regulators so that the phases of the plurality of pulse signals are different from each other, and outputs the plurality of adjusted pulse signals to respective switch circuits of the plurality of switching regulators.

Switching power supply circuit capable of timing adjustment of signal

A switching power supply circuit for generating an output voltage at an output node based on an input voltage at an input node includes a reference voltage generating circuit configured to generate a reference voltage such that during an initial start-up period of the reference voltage a voltage rise rate of the reference voltage within a first predetermined period from a start point of the initial start-up period and a voltage rise rate thereof within a second predetermined period immediately preceding an end point of the initial start-up period are smaller than a voltage rise rate thereof in a period between the first predetermined period and the second predetermined period, a coil disposed between the input output nodes, and a switch circuit configured to switch on and off to control current through the coil in response to comparison between the reference voltage and a voltage proportional to the output voltage.

Growing community of inventors

Hyogo, Japan

Katsuhisa Furuse