Abstract: An image sensing apparatus, which has a constant-voltage driven stepping motor, comprises a PWM waveform generation part that generates pulse signals to be applied to switching devices; and a PWM waveform determination section that determines a PWM waveform to be generated by the PWM waveform generation section. The PWM waveform determination section determines, in accordance with the determined rotation speed value and output torque value of the stepping motor, a duty ratio range that is a range extending from the minimum to the maximum of the duty ratio of the pulse signals. It is designed that the higher the rotational speed value is, the wider the duty ratio width is.

Abstract: A stepper motor driving a driven member is calibrated by periodically driving the member from its current operational position to an end stop of the driven member's total travel range; however, the driven member approaches the end stop in a series of ever-shorter travel segments. The first travel segment is less than ? the total travel range to compensate for a possible sudden speed reversal, which can be accidentally triggered by the driven member reaching and “bouncing off” the end stop. Limiting the commanded first travel segment to less than ? the total travel range prevents the driven member from reaching an opposite travel limit should the driven member suddenly reverse direction at three times the normal forward speed, wherein such triple speed is characteristic of reverse-speed situations.

Abstract: A method of reading an image by an image sensor comprising: a) reciprocating a carriage from a predetermined position in a predetermined direction by rotating a stepping motor to which a second current value smaller than a first current value is supplied; and b) detecting whether or not the carriage after reciprocating is disposed at the predetermined position, by the sensor, wherein, in the case where the sensor detects that the carriage after reciprocating is disposed at the predetermined position, when the image sensor reads an image, the first current value is supplied to the stepping motor, and in the case where the sensor detects that the carriage after reciprocating is not disposed at the predetermined position, when the image sensor reads an image, a current value obtained by adding a third current value to the first current value is supplied to the stepping motor.

Abstract: A system for calculating control pulse duration for optimal stepper motor performance. Duration of control pulses to a stepper motor is increased until stepper motor function begins. The duration of control pulses continues to be increased. It is determined whether stepper motor failure is detected. In response to detecting a failure, the duration of control pulses at the time of the failure is recorded. The duration of control pulses is decreased until stepper motor function is restored. The duration of control pulses continues to be decreased. It is determined whether a second failure is detected. In response to detecting a second failure, the duration of control pulses at the time of the second failure is recorded. A control pulse duration is calculated that optimizes performance of the stepper motor using recorded control pulse duration data. The calculated control pulse duration is applied to the stepper motor.

Abstract: A control device for a stepping motor is provided that can reduce torque generated by a motor and control the expansion of a speed deviation when the rotational speed of a rotor exceeds a speed command. The control device includes first judging means (27) for judging whether a positional deviation of a rotor is within a predetermined range, second judging means (28) for judging whether a sign of the positional deviation and a sign of a speed deviation coincide with each other, and phase setting means (34 to 35) for setting a winding current command phase.

Abstract: A fluorescence microscopy sequencer comprises a fluid transport subsystem in which reagents are pumped through a series of multi-port valves to a mixer or one or more flow cells, or directly into the flow cell(s). The one or more multi-port valves can be mounted upon a fluids manifold having syringe tubes mounted on the opposite side. Mounted on a movable support, the manifold may be brought into and out of fluid communication with a storage block comprising the plurality of reagents. In another embodiment, the sequencer comprises a beamsplitter indexer that facilitates the quick and reliable switching of filter cubes through use of a stepper motor. In yet another embodiment, a motion control system is provided in which an inertial reference is interposed between and directly coupled to a first and second axis of control, thereby minimizing any low structural resonant frequencies and enabling high performance (high frequency response) motion control.

Abstract: A control device for a stepping motor of the present invention stores setting data for controlling a state of the stepping motor in a data storage unit for each of a plurality of basic control items obtained by classifying control from activation to stoppage of the stepping motor. In addition, the control device for the stepping motor includes a plurality of modules that execute processing with respect to the basic control items and a module control unit that specifies the order of executing the processing by the plurality of modules in advance, and controls the stepping motor by operating the modules in accordance with the specified executing order based on the setting data stored in the data storage unit.

Abstract: A stepping motor controller includes: a pulse frequency adjustment circuit that receives a command pulse having a first frequency from an external controller that outputs the command pulse in accordance with an interrupt process performed periodically by the external controller, and generates an alternative command pulse having a second frequency that is lower than the first frequency; and a motor driving circuit that receives the command pulse through the pulse frequency adjustment circuit, and controls a stepping motor to rotate on the basis of the command pulse. The pulse frequency adjustment circuit outputs the alternative command pulse to the motor driving circuit instead of the command pulse received from the external controller, when the first frequency exceeds a predetermined level.

Abstract: A method and apparatus for determining speed of a stepper motor. In one embodiment of the method, a first terminal of a first coil of the stepper motor is coupled to an input of a multibit digital-to-analog (A/D) convertor. The stepper motor's a rotor is rotated about an axis while the first terminal is coupled to the multibit A/D convertor. An analog signal is induced at the first terminal generating while the rotor is rotating about the axis. The multibit A/D convertor receives the analog signal induced at the first terminal. The multibit A/D convertor generates a plurality of multibit digital signals in response to receiving the analog signal. The multibit digital signals can be processed to determine the rotational speed at which the rotor was rotating when the A/D convertor generated the plurality of multibit digital signals.

Abstract: A method and system for controlling a current regulator motor control for parking a motor rotor in a predetermined position, wherein a first current command and a first angle command are supplied to a current regulator for a first parking time, to move the rotor to an intermediate position; and a second current command and a second angle command are supplied to the current regulator for a second parking time, to move the rotor to a predetermined position. The current regulator may have a normal voltage output range, and a circuit may be provided for limiting a voltage output of the current regulator to a reduced voltage output range for at least a portion of the parking time. Advantageously the motor is a permanent-magnet synchronous motor with sinusoidal back-EMF.

Abstract: A servo driving method of the present invention to drive a stepping motor driven by a predetermined driving pulse, by a servo control method, is comprising a setting step of setting a driving mode of the stepping motor switchable at least between a first driving mode, in which the stepping motor is driven with a relatively large current, and a second driving mode, in which the stepping motor is driven with a relatively small current, and a switching step of switching the driving mode between the first driving mode and the second driving mode when a predetermined mode switching information is given. Thereby, it becomes possible to reduce the power consumption by supplying power efficiently to the stepping motor.

Abstract: A synchronization control system includes plural controlling object apparatuses connected through first and second wired OR lines. Each controlling object apparatus includes a function of switching an output to the first wired OR line from a first state to a second state in an odd numberth synchronization waiting state and switching an output to the second wired OR line from the first state to the second state in an even numberth synchronization waiting state. A control apparatus determines an odd numberth synchronization in response to changing of the first wired OR line from the first state to the second state when all the controlling object apparatuses enter the odd numberth synchronization waiting state, and determines an even numberth synchronization in response to changing of the second wired OR line from the first state to the second state when all the controlling object apparatuses enter the even numberth synchronization waiting state.

Abstract: There are included a control circuit to control sequence of excitation of a stepping motor, a switching circuit to switch electric power to be supplied to the stepping motor based on an instruction from the control circuit, and a stop circuit to stop an operation of the switching circuit in a case where temperature of the switching circuit becomes a specified temperature or higher, and the control circuit controls the switching circuit in a mode where the stop circuit operates before the stepping motor is damaged by heat.

Abstract: A motor-driving circuit drives a plurality of motors of different types. The motor-driving circuit includes a plurality of H-bridge circuits for outputting driving signals to the motors, a controller for controlling the plurality of H-bridge circuits, a setting section for setting up the controller, and terminals for inputting setting data.

Abstract: In a driving apparatus, a drive force interruption/transmission device transmits or interrupts a drive force from a drive source, a load unit is operated by the drive force transmitted from the drive force interruption/transmission device, a torque control unit varies the output torque of the drive source, a drive force interruption control unit controls the operation of the drive force interruption/transmission device, and a drive timing control unit for controls the torque control unit and the drive force interruption/transmission control unit. After the output torque of the drive force is increased the drive force from the drive source is transmitted to the load unit.

Abstract: A method of controlling a stepping motor including a stator having a driving coil wound therearound, and a rotor, the method comprising: performing a driving control of driving the rotor at a predetermined step angle and a stop control of stopping the rotor at a predetermined stop position; and if a predetermined rotation range of the rotor including a range having a maximum position holding torque that is a maximum holding torque of the rotor when the rotor stops with the driving coil thereof being supplied with a current, is referred to as a first rotation range, and a predetermined rotation range of the rotor other than the first rotation range is referred to as a second rotation range, in the stop control, setting the sum of currents supplied to the driving coils to stop the rotor at a target stop position within the second rotation range to be larger than the sum of currents supplied to the driving coils to stop the rotor at a target stop position within the first rotation range.

Abstract: A method and apparatus for driving a stepper motor and using the stepper motor as a rotary sensor when the stepper motor is not being driven.

Abstract: A method for monitoring a step motor is provided, wherein the step motor rotates from a start position to an end position and then back to the start position repeatedly. The monitoring method includes: detecting a status signal of the step motor and a command signal received by the step motor in real time; recording a variation of the difference between the command signal and the status signal vs. time as an error data; and determining whether the step motor is starting from the start position, in action, reaching the end position, or returning to the start position according to the status signal and the command signal. If it is determined that the step motor is in action, the error data is recorded as a tracking error, and whether an alarm is issued is determined according to the tracking error.

Abstract: A method of controlling a stepping motor, comprising: performing a driving control of driving a rotor at a predetermined step angle; and performing a stop control of giving a driving circuit of the stepping motor a stop instruction for stopping the rotor at a position that is before or beyond a target stop position by a minuter step angle than the step angle in the driving control in a direction in which the rotor is rotated when to stop the rotor at the target stop position.

Abstract: A method and structure receives a desired rotational speed and/or step frequency for an electric motor. If the desired rotational speed is above a predetermined limit, the method performs closed-loop mode control of coil current of the electric motor by varying the average voltage supplied to the electric stepper motor according to observed feedback current from the current feedback loop connected to the electric stepper motor. To the contrary, if the desired rotational speed is not above the predetermined limit, the method performs open-loop mode control of coil current of the electric stepper motor by setting the average voltage supplied to the electric stepper motor according to values computed from the step frequency, irrespective of the observed feedback current from the current feedback loop.

Abstract: A detector device and a method for detecting a stall condition in a stepper motor, wherein the accumulated value of the back EMF is compared to a stall threshold when the stepper motor has exceeded a pre-determined rotational velocity threshold, the accumulated value of the back EMF representing a condition of the stepper motor, specifically a failure of the accumulated back EMF value to exceed the stall threshold indicating a stall condition of the stepper motor.

Abstract: A step motor control circuit that does not fix a reference voltage of a step motor control signal. The step motor control circuit may include a digital-to-analog (DAC) signal generator configured to generate first and second DAC signals in response to a step motor error signal, a gain adjust block configured to control gains of the first and second DAC signals in response to a control signal and output first and second step motor control signals, and a gain controller configured to output the control signal in response to a mode signal and a gain control signal, in which the first and second step motor control signals are pulse trains including a reference voltage, and the reference voltage may be a fixed voltage when the mode signal indicates a normal mode and the reference voltage may be a variable voltage when the mode signal indicates a power consumption reduction mode.

Abstract: A step motor drive circuit has a first transistor pair having first and transistors, a second transistor pair having third and fourth transistors, and fifth and sixth transistors connected in parallel with the first and third transistors, respectively. A driving circuit alternately drives the first transistor pair and the second transistor pair to an ON state in a state of rotating the motor (first stated), and shortcircuits drive terminals of the motor by driving the first and third transistors to an ON state and driving the second and the fourth transistors to an OFF state in a state of braking the motor (second state).

Abstract: A method and a system are disclosed for preventing stepper motor control signals from being applied to a stepper motor drive circuit in order to stop a stepper motor when an interlock situation is present. A sequence of one or more control signals is generated by a motion control system and passed to one or more interlock logic gates connected in series. The interlock logic gates have an enable signal input which allows the control signals to pass through to the stepper motor drive circuit if the enable input signal is set to a logic level of “1”. On the other hand, the interlock logic gates will prevent the control signals from reaching the stepper motor drive circuit if the enable input signal is set to a logic level of “0”. The logic level of the enable input signal may be connected to a switch, relay, or an integrated circuit responsive to an interlock situation such as the opening of an access door.

Abstract: An emitting direction control apparatus for a lamp is provided with: a driver for deflecting an emitting direction for a lamp; and a controller that control the driver to perform a deflection. The controller includes an initialization function, for setting, at an initial position, a stepping motor that serves as a driving source for the driver. The initialization function detects a first current positional angle for the stepping motor; when the first current positional angle is greater than a reference angle, rotates the stepping motor in a bumping direction at a high speed until the reference angle is reached; after the reference angle has been reached, rotates the stepping motor to a bumped position an initial number of steps at a low speed; and after the bumped position has been reached, rotates the stepping motor in the reverse direction a predetermined number of steps and sets the stepping motor in the initial position.

Abstract: System and method for controlling a stepper motor. A current position of the stepper motor may be received. A position error of the stepper motor may be determined using the current position of the stepper motor. A velocity profile may be maintained based on the position error, such that it tracks the position error. A position correction value may be determined based on the velocity profile, e.g., by integrating a portion of the velocity profile. A new position value may be generated to drive the stepper motor. An output position value to the stepper motor may be provided to drive the stepper motor. The output position value may incorporate the new position value and the position correction value and may be operable to reduce position error of the stepper motor.

Abstract: The lead or lag relationship between the stator and rotor of a stepper motor is monitored on a continuing basis by an incremental encoder, in feed-back relation, and adjusts the lead or lag to within optimum range values to thereby prevent motor stalls and motor cogging.

Abstract: A stepper motor apparatus controls a stepper motor by taking a maximum response speed and maximum response acceleration of the stepper motor into account.

Abstract: A step motor driving apparatus includes a micro control unit (MCU), a pulse generator, a first step motor driver, a second step motor driver, and a communication port. The first step motor driver is configured for driving a first step motor and connected to the MCU. The second step motor driver is configured for driving a second step motor and connected to the MCU. The MCU is connected to the second step motor driver via the pulse generator. The pulse generator is configured to supply pulse signals to the second step motor driver. The communication port is connected to the MCU. The MCU receives a corresponding command from an external control apparatus via the communication port. The MCU selectively controls the first step motor driver to drive the first step motor or controls the second step motor driver to drive the second step motor according to the command.

Abstract: An input shaft speed signal for rotating a motor at a predetermined rotational speed is output from a rotation control unit to the motor. A rotational speed reduced by a speed reduction device with elastic bodies is detected by an output rotation sensor. A CPU obtains slippage by calculating a reduction ratio based on the detected output shaft speed signal and input shaft speed signal. Load torque is determined from the obtained slippage. A current value to be supplied to the motor is determined so that the motor produces torque corresponding to the load torque. The current value to be supplied from a motor driver to the motor is thus controlled.

Abstract: In a micro-step drive and driving method of a stepping motor, the stepping motor generates a drive force for movement on a prescribed path of a moving unit provided in an electrically driven device, a standard point and a target point of an operation are set on the path, the stepping motor is rotated such that the moving unit passes through the standard point, a count value of a stable stop point of the stepping motor that is closest to a count value at the point of time when the moving unit passed through the standard point is specified, the specified count value is set as a start point for controlling a rotation angle of the stepping motor, and the stepping motor is rotated, and stopped at the count value of the selected stable stop point.

Abstract: A feed dog drive motor and an X-direction motor are connected to common input/output ports of a CPU via first and second driver IC circuits, respectively. In response to a drive switching signal generated from the CPU, selected one of the first and second driver IC circuits is enabled, causing the feed dog drive motor and the X-directional motor to selectively energize. A common driver IC circuit can be used in place of the first and second driver IC circuits. With such a configuration, the number of input/output ports of the CPU as well as the number of driver IC circuits can be reduced.

Abstract: A method and structure receives a desired rotational speed and/or step frequency for an electric motor. If the desired rotational speed is above a predetermined limit, the method performs closed-loop mode control of coil current of the electric motor by varying the average voltage supplied to the electric stepper motor according to observed feedback current from the current feedback loop connected to the electric stepper motor. To the contrary, if the desired rotational speed is not above the predetermined limit, the method performs open-loop mode control of coil current of the electric stepper motor by setting the average voltage supplied to the electric stepper motor according to values computed from the step frequency, irrespective of the observed feedback current from the current feedback loop.

Abstract: A stepper motor driving a driven member is calibrated by periodically driving the member from its current operational position to an end stop of the driven member's total travel range; however, the driven member approaches the end stop in a series of ever-shorter travel segments. The first travel segment is less than ? the total travel range to compensate for a possible sudden speed reversal, which can be accidentally triggered by the driven member reaching and “bouncing off” the end stop. Limiting the commanded first travel segment to less than ? the total travel range prevents the driven member from reaching an opposite travel limit should the driven member suddenly reverse direction at three times the normal forward speed, wherein such triple speed is characteristic of reverse-speed situations.

Abstract: A multi-purpose scan device using the same power source includes a flatbed scanner, an ADF, a motor, and a power-switching mechanism. The flatbed scanner has a scanning module and a power transmission mechanism for moving the scanning module back and forth in the flatbed scanner. The ADF has a sheet-feeding mechanism for feeding a document across the scanning module, which scans the document. The power-switching mechanism selectively transmits power of the motor to the sheet-feeding mechanism and the power transmission mechanism.

Abstract: An electrostatic marking system is provided having a power source(s) in each of its processing stations. A specialized power source is made up of two stepper motors in operative connection to a planetary gearset. This gearset is comprised of a sun gear, a set of planet gears supported by a carrier, and a ring gear. This power source provides a continuously variable gear ratio between each stepper motor and its load.

Abstract: When the magnitude of a traverse signal exceeds a predetermined level, the value of a microstep drive signal is changed by one microstep angle so that the rotation angle of the stepping motor changes in a rotation direction in which the magnitude of the traverse signal decreases. A determination is made as to whether or not the magnitude of the traverse signal becomes a predetermined level or less. When the magnitude of the traverse signal does not become the predetermined level or less, the magnitude of the microstep drive signal is returned to the pre-change value and the value of the microstep drive signal is incremented by an additional microstep angle so that the rotation angle of the stepping motor changes in a rotation direction in which the magnitude of the traverse signal decreases.

Abstract: A pattern register stores an excitation pattern of stepping motors. A first pattern control unit reads out an excitation pattern for n bits from a predetermined address of a pattern register for supplying the same to an external motor driver. A second pattern control unit reads out an excitation pattern for the same n bits as in the first pattern control unit from a predetermined address of the pastern register and supplies the same to an external motor driver. An output control unit selectively outputs a first output mode for using the first pattern control means and the second pattern control means independently, or a second output mode for using them in an interlocked manner.

Abstract: A stepper motor is controlled by a driver having a constant and maximum frequency input in order to correct for camera shake. The need for variable frequency devices is eliminated, thereby reducing the cost and complexity of the system.

Abstract: A stepping motor driving device drives a stepping motor according to a drive pulse of a step signal. A phase matching unit matches, at a time when there is a possibility that a rotor and a phase signal are out of phase with each other, phases of the rotor and the phase signal by applying at least one drive pulse after energizing the stepping motor for a predetermined time and applying a phase signal having a predetermined duration for a final pulse.

Abstract: The circuit comprises a pulse width modulated (PWM) input signal, a resistor, an instrumentation amplifier, a filter and an analog to digital converter. The method of performing synchronization comprises sampling an analog signal and forming a digital data stream representing the signal, filtering the data stream to remove harmonics, measuring an approximate level of ripple in the data stream, detecting a change in the level of ripple, and based upon change in the level of ripple, determining if a stall has occurred.

Abstract: A control device for a stepping motor is provided that can reduce torque generated by a motor and control the expansion of a speed deviation when the rotational speed of a rotor exceeds a speed command. The control device includes first judging means (27) for judging whether a positional deviation of a rotor is within a predetermined range, second judging means (28) for judging whether a sign of the positional deviation and a sign of a speed deviation coincide with each other, and phase setting means (34 to 35) for setting a winding current command phase.

Abstract: The present invention discloses a high-current high-resolution driving circuit comprising a controller, a digital-to-analog converter and a voltage-to-current converter. The controller is provided for receiving a control signal for operating a load and outputting a digital signal corresponding to the control signal. The digital-to-analog converter is provided for generating an analog voltage signal corresponding to the digital signal. The voltage-to-current converter is provided for generating a current signal corresponding to the analog voltage signal and transmitting the current signal to the load in order to drive the load.

Abstract: The present invention relates to a method and a system for compensating for a position error of a step motor. A method for compensating for a position error of a step motor includes: sequentially inputting a predetermined number of a pulse as a rotator position command to a step motor driver; driving a step motor in a micro step method based on the rotator position command and a predetermined current command table; detecting an actual position of a rotator of the step motor while the step motor is being driven; calculating a position error by comparing the rotator position command and the detected actual position of the rotator; and compensating for the predetermined current command table based on the calculated position error. According to the present invention, a position error which may occur when the step motor is driven by a micro step method can be removed.

Abstract: A step motor driving circuit is provided. An exemplary step motor driving circuit includes an input voltage source set, a reference voltage source, a voltage level shift unit, a logic unit, a reset voltage source, and an output voltage terminal. The input voltage source set provides an input voltage set. The reference voltage source provides a reference voltage. The voltage level shift unit raises one of the levels of the input voltage set to a level of the reference voltage. The logic unit receives the reference voltage and the input voltage set and outputs a control voltage. The reset voltage source outputs a reset voltage to reset the logic unit. The output voltage terminal receives the control voltage and outputs an output voltage.

Abstract: A method and device for detecting an initial excitation phase of a stepping motor is provided, by which an initial excitation phase of a rotor corresponding to a position of a stopper can be detected with a unit of a stepping angle of a microstep drive which is smaller than that of a full step drive without using elements such as magnetoelectric elements. Upon appropriately changing an excitation phase of a stepping motor, on the basis of a generated pattern of an induced electromotive force in an exciting coil in a non-excitation state upon a full step drive, whether or not a pointer comes in contact with a stopper to stop a reverse rotation of the pointer and rotor is judged so that it is specified on which excitation phase the pointer and rotor are reversed, thereby detecting an initial excitation phase of the rotor corresponding to a position of the stopper.

Abstract: A speed control method of controlling a stepping motor to have a uniform instantaneous speed and an apparatus suitable for the same are provided. The stepping motor speed control method includes: calculating a repeated speed error for each phase while rotating a stepping motor at a constant speed and storing the calculated repeated speed error phase by phase; measuring a rotation speed of the stepping motor; sequentially and repeatedly reading the stored repeated speed errors phase by phase by synchronizing with the rotation of the stepping motor; and controlling the speed of the stepping motor with reference to the target speed, the measured speed and the repeated speed error for each phase. Accordingly, the stepping motor speed control apparatus rotates a stepping motor at a uniform instantaneous speed by controlling a rotation speed of the stepping motor phase by phase.

Abstract: A motor control circuit for reducing current consumption. A stepping motor control circuit includes an A/B phase current setting signal generation circuit for generating an A/B phase current signal setting signals provided to a stepping motor driver to supply a stepping motor with a predetermined amount of drive current. Based on a switch signal, first and second switches selectively output an A/B phase current setting signal and an A/B phase reference signal, for reducing the drive current of the stepping motor more than the A/B phase current setting signal. An intermittent drive control circuit generates the switch signal. The stepping motor control circuit provides the motor driver with the A/B phase reference signal in accordance with the switch signal.

Abstract: A stop-detection method intended for a multi-phase synchronous geared motor that is controlled in a stepping mode, which measures the sum of the currents circulating in each of the N phases of the geared motor. In the method the stop detection threshold is calculated in relation to the change in the sum of the currents.

Abstract: A stepping motor control apparatus that is able to electrically detect the load of the stepping motor and effectively prevent step-outs by means of an inexpensive configuration. The stepping motor control apparatus is equipped with a microcomputer (10) that outputs a command pulse, a chopper-type constant current driver (20) that outputs a drive current that corresponds to the input command pulse to the stepping motor (5) and outputs a chopper signal to keep the output drive current fixed, and a load detection circuit (30) that detects the chopper signal to detect the load of the stepping motor (5). The load detection circuit (30) is equipped with a waveform shaping circuit (50) that makes the chopper signal waveform continuous to convert it to a pulse or voltage, and it detects the load of the stepping motor by means of the width of the pulse or the voltage value.