"step-by-step" Motors In Closed-loop Servos Patents (Class 318/685)
  • Patent number: 7170254
    Abstract: A stepper motor driving apparatus, includes a stepper motor; a driven member interlocked with a rotation of a rotor of the stepper motor, a stopper stopping the driven member in a zero position, a controller controlling the excitation state of an excitation coil of the stepper motor, an induced voltage waveform detector detecting an induced voltage waveform generated on the basis of change of magnetic flux in accordance with the rotation of the rotor, and a zero position detector detecting whether the driven member is stopped in the zero position. The zero position detector includes a comparator which compares a time T2 in which each induced voltage waveform exceeds a predetermined threshold value with a predetermined contact determining reference time Tref, and a determinant which determines whether the driven member is stopped in the zero position by the stopper based on a result of the comparison by the comparator.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: January 30, 2007
    Assignee: Yazaki Corporation
    Inventor: Yoshihisa Yamada
  • Patent number: 7166981
    Abstract: An actuator, which allows a controller to be commonly applied to a plurality of models without requiring complicated setting operation of control parameters, and is superior in cost effectiveness, reusability and expandability, is provided. And further, a motor unit and a controller unit constituting the actuator are provided. The motor unit is equipped with a motor, a motor drive circuit and a parameter memory, which stores characteristic parameters necessary for controlling the motor. A controller unit, which is adapted so as to be detachable to the motor unit, is provided with a motor control circuit and a communication control circuit. When the controller unit is attached to the motor unit, characteristic parameters stored in the parameter memory are loaded via a communication connector, and used for setting control parameters for the motor control circuit.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: January 23, 2007
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kazushige Kakutani, Shinya Kataoka, Naoto Tojo
  • Patent number: 7157879
    Abstract: Apparatus for optimizing performance of a stepper motor includes interaction between on-hardware system drivers and a host controlling computer through an intermediate target computer. The command instructions from the host computer are optimized by the interaction using an objective function to define the best performance of the stepper motor and real-time feedback from operation of the motor. A method for optimizing the stepper motor performance is also disclosed.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: January 2, 2007
    Assignee: Rensselaer Polytechnic Institute
    Inventors: John R. Rogers, Kevin Craig
  • Patent number: 7154245
    Abstract: The frequency of the pulse width modulator within a step motor control circuit is increased above a base frequency under defined conditions to enable more accurate construction of the phase current waveform for preventing mid-range resonance. The PWM frequency is stepped between frequencies by a fixed amount above the base frequency, to prevent the excitation of system harmonics and prevent step motor operational instability.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: December 26, 2006
    Assignee: IMS Inc.
    Inventors: David Coutu, Robert A. Fournier
  • Patent number: 7148642
    Abstract: A control circuit is described in which a single input terminal receives digital control signals and analog control signals. In accordance with the principles of the invention, the control circuit includes an automatic power down circuit to place the control circuit into a low power draw or “sleep” mode whenever predetermined conditions are present. The automatic power down circuit monitors the single input terminal and when no demand for motor operation occurs for a predetermined period of time, the automatic power down circuit operates to place the control circuit into the low power draw mode.
    Type: Grant
    Filed: April 27, 2006
    Date of Patent: December 12, 2006
    Assignee: Andigilog, Inc.
    Inventors: Robert Alan Brannen, Jade H. Alberkrack
  • Patent number: 7145309
    Abstract: Provided herewith is an improved scheme for parking a load such as an indicator pointer and calibrating its position in a system for controlling the position of the load. The system also has a stopper for physically impeding the load when it is to be parked. In one embodiment, a parking method involves driving the motor in a reduced torque mode to move the load toward the stopper, stopping the load at the stopper while the motor is driven in the reduced torque mode, and maintaining the motor in a reduced torque mode until transitioning to an insignificant torque mode.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: December 5, 2006
    Assignee: Freescale Semiconductor, Inc.
    Inventors: Thomas J. Reiter, Peter J. Pinewski
  • Patent number: 7145308
    Abstract: An apparatus for converting electrical energy into mechanical energy includes a plurality of iron segments disposed in a circular, generally donut-shaped body that is substantially non-magnetic, and which forms a rotor of an electric motor. Each of a first plurality of coils is attached to a housing and form a stator. Each coil includes a hollow center and is disposed around the body. The coils are pulsed on and off in a pattern to create a magnetic field that attracts the iron segments urging them sufficient to rotate the body. The body forms a rotor of the electric motor. A second plurality of coils are optionally included and energized in an opposite or offset pattern as compared to the first plurality to increase torque or aid in starting rotation of the rotor. A permanent magnet in the rotor is used to indicate the position of the rotor relative to the stator. The rotor includes a pair of horseshoe-shaped overlapping halves that fasten together.
    Type: Grant
    Filed: January 24, 2006
    Date of Patent: December 5, 2006
    Inventor: Theodore O Chase
  • Patent number: 7138784
    Abstract: Optimized pulse commands are utilized for reducing vibration in a step motor, the optimized commands being created by correcting position, velocity, acceleration, deceleration, and movement distance terms of a basic motion profile with position feedback information generated during operation.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: November 21, 2006
    Assignee: Oriental Motor Boston Technology Group Incorporated
    Inventor: Masayuki Someya
  • Patent number: 7129669
    Abstract: A motor controller comprising, a detector configured to perform a difference processing for information relating to a counter electromotive force and an induced electromotive force generated by a stepping motor, and to generate a driving control signal based on a result of the difference processing, and a driver configured to drive the stepping motor based on the driving control signal.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: October 31, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yutaka Mamyoda
  • Patent number: 7129670
    Abstract: A drive device includes stepper motors, each having an excitation coil and a rotor rotating based on variation in the excitation state of the excitation coil; driven members, each moving in accordance with the rotation of the rotor of the corresponding stepper motor; stoppers, each stopping the driven member mechanically at a zero position; and a controller, controlling the respective stepper motors so as to selectively performs either a normal operation in which the stepper motor is driven so as to rotate, or a zero-position detection operation in which the stepper motor is driven so that the driven member is moved to the stopper. The controller starts to perform the zero-position detection operation simultaneously in all of the stepper motors and changes the stepper motor which has terminated the zero-position detection operation to the normal operation without waiting for the termination of the zero-position detection operation in other stepper motors.
    Type: Grant
    Filed: June 7, 2004
    Date of Patent: October 31, 2006
    Assignee: Yazaki Corporation
    Inventors: Masaki Oishi, Hidemasa Umehara
  • Patent number: 7129671
    Abstract: A reference signal generation unit 110a generates a reference signal VCA representing a limit indicator. Under the control of a PWM control unit 120a, a bridge rectification circuit 130a controls the current supplied to a coil 19a to the limit indicator, using a current chopper method. Therewith, the circuit 130a implements synchronous rectification where transistors 10 and 12 are brought into conduction when the current supply is stopped, forming a closed circuit with the coil 19a, and a regenerative current circulates in the closed circuit. During a time period when the reference signal is decreasing relatively rapidly, a SR prohibition unit 115a prohibits the transistor 10 or 12 from being brought into conduction when the current supply is stopped, and thereby the decay of regenerative current is accelerated.
    Type: Grant
    Filed: October 25, 2004
    Date of Patent: October 31, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shingo Fukamizu, Katsuhiro Onishi
  • Patent number: 7127369
    Abstract: A system with a sensor assembly is used to determine direction of movement of an object so that accuracy of position calculation is improved. The sensor assembly measures at least two operational characteristics and generates corresponding operational characteristic signals. A control unit monitors and compares transitions of the signals to more accurately determine direction of movement for the object.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: October 24, 2006
    Assignee: Siemens VDO Automotive Corporation
    Inventors: Tomohiro Fukumura, Sanjaya Kumar Dash
  • Patent number: 7116074
    Abstract: A stepper motor accelerating system is used for accelerating a stepper motor from a current rotational speed to a target rotational speed. The stepper motor accelerating system comprises a controller, a pulse generator, and a driver. The controller stores a safety acceleration curve. The safety acceleration curve is defined by shifting a characteristic curve of the stepper motor with a safety margin. The controller compares the current rotational speed and the target rotational speed with the safety accelerating curve, and then gets two corresponding points on the safety accelerating curve. The controller generates a real accelerating curve based on these two corresponding points. The pulse generator receives the real accelerating curve and converts to a pulse signal. The driver receives the pulse signal, and then drives the stepper motor with the pulse signal. The present invention accelerates the stepper motor base on the safety accelerating curve.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: October 3, 2006
    Inventor: Ping-Hung Kuo
  • Patent number: 7116070
    Abstract: A system and method for sensor less control of a stepper motor is described. The system and method includes estimation of the position of a rotor of the motor by way of sensing circuitry on the windings of the motor, without the use of positional sensors. The system and method of stepper motor control further includes magnetic field optimization for increasing the torque generating component of a magnetic field generated by stators of the motor, and magnetic field weakening for countering some of the effects of back electromotive force generated by the magnetic rotor.
    Type: Grant
    Filed: July 15, 2005
    Date of Patent: October 3, 2006
    Assignee: Agile Systems Inc.
    Inventor: David Kyle MacKay
  • Patent number: 7112932
    Abstract: A system-on-a-chip (SOC) in CMOS technology capable to support high voltage applications has been achieved. The single chip system of the present invention comprises high-voltage circuitry, a complete micro-controller system including all timing control, interrupt logic, flash EEPROM program memory, RAM, flash EEPROM data memory and I/O necessary to implement dedicated control functions, and a core and system peripheral bus. A preferred embodiment of the invention is shown driving a DC-motor in a H-bridge configuration, having an AMR-position detection and control. A pulse width modulation (PWM) is applied to high-voltage (30 to 60 Volts or in lower ranges less than 30 Volts) CMOS buffers for steering CMOS-FETs or relays of the motor H-bridge.
    Type: Grant
    Filed: October 25, 2004
    Date of Patent: September 26, 2006
    Assignee: Dialog Semiconductor GmbH
    Inventors: Rainer Krenzke, Eric Marschalkowski
  • Patent number: 7103442
    Abstract: A CPU for a motor driving apparatus of an image forming apparatus excites a predetermined phase winding among plural phases of a stepping motor for a predetermined time period. Thereafter, before a rotation of the motor is started, it is judged whether there is the possibility of deviating a positional relationship between a rotor and a stator of the motor from a positional relationship determined by the excitation of the predetermined phase winding for the predetermined time period, by an external force, on the basis of judgement whether a door is opened for jam treatment. If the possibility of deviation is judged, the predetermined phase winding among plural phases of the stepping motor is excited again for a predetermined time period.
    Type: Grant
    Filed: March 30, 2001
    Date of Patent: September 5, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Kenji Fukushi, Kazuki Miyamoto, Masahiro Kurahashi
  • Patent number: 7088072
    Abstract: A stepping motor control system according to the present invention includes a counting mechanism for counting the number of steps of the pulse train command, a latch mechanism for holding a counting value of the counting mechanism with a latch signal and finding a position command, a reference signal generating mechanism for generating the latch signal and a reference clock signal, a first calculating mechanism for calculating a pulse spacing of the pulse train command with the reference clock signal, and a second calculating mechanism for calculating a time interval from generation of the pulse train command to generation of the latch signal with the reference clock signal. In the stepping motor control system, the position command is corrected using command pulse spacing information calculated by the first calculating mechanism and time difference information calculated by the second calculating mechanism.
    Type: Grant
    Filed: October 27, 2005
    Date of Patent: August 8, 2006
    Assignee: Japan Servo Co., Ltd.
    Inventors: Yoshifumi Kuwano, Hiroaki Taka, Akio Takemori
  • Patent number: 7078839
    Abstract: The present invention relates to a self-bearing step motor, and more particularly, to self-bearing step motor system and a control method thereof, wherein a rotor can be supported by magnetic force without adding an additional winding for supporting the rotor to a step motor having no mechanical bearing for supporting the rotor.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: July 18, 2006
    Inventor: Dae-gon Kim
  • Patent number: 7068006
    Abstract: At the start of driving a stepping motor, a CPU sets the switching widths of the first through eighth states in a pulse width setting register, sets the switching counts of the first through eighth states in a pulse switching count register, and sets the start of driving the stepping motor in a driving start register. A latch then outputs an excitation pulse, and the stepping motor is accelerated, driven at a constant speed, decelerated, and stopped. By setting the switching widths and switching counts of the first through eighth states at the start of driving and setting the start of driving, the CPU need not control the stepping motor, reducing the process burden on the CPU.
    Type: Grant
    Filed: August 5, 2004
    Date of Patent: June 27, 2006
    Assignee: Casio Computer Co., Ltd.
    Inventor: Masateru Nishimoto
  • Patent number: 7068007
    Abstract: A stepping motor driving system and process according to the present invention controls a switching element in such a manner that motor supply current is passed through a motor coil until a coil current detection value reaches an upper limit set point, motor reflux current is passed through the motor coil until predetermined time elapses since the motor supply current begins to flow after the coil current detection value reached the upper limit set point, motor regeneration current is passed through the motor coil until the coil current detection value reaches a lower limit set point when predetermined time has passed, and motor reflux current is passed through the motor coil until predetermined time elapse since the motor regeneration current begins to flow after the coil current detection value reached the lower limit set point.
    Type: Grant
    Filed: October 21, 2005
    Date of Patent: June 27, 2006
    Assignee: Japan Servo Co., Ltd.
    Inventor: Charles Simson Silitonga
  • Patent number: 7064510
    Abstract: A control circuit is described in which a single input terminal receives digital control signals and analog control signals. In accordance with the principles of the invention, the control circuit includes an automatic power down circuit to place the control circuit into a low power draw or “sleep” mode whenever predetermined conditions are present. The automatic power down circuit monitors the single input terminal and when no demand for motor operation occurs for a predetermined period of time, the automatic power down circuit operates to place the control circuit into the low power draw mode.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: June 20, 2006
    Assignee: Andigilog, Inc.
    Inventors: Robert Alan Brannen, Jade H. Alberkrack
  • Patent number: 7061203
    Abstract: A controlled stepping motor is electrically connected to a controller and a loading device. A method of controlling the stepper motor includes utilizing the controller to output a control signal to the stepping motor according to a target displacement and a first index parameter, utilizing the stepping motor to move the loading device according to the control signal, utilizing the controller to calculate a difference between the target displacement and an actual displacement of the loading device, and utilizing the controller to generate a second index parameter for updating the first index parameter according to the first index parameter, the difference, and the actual displacement.
    Type: Grant
    Filed: March 24, 2004
    Date of Patent: June 13, 2006
    Assignee: VIA Technologies Inc.
    Inventors: Yi-Chung Chan, Jacky Lee, Alex Lin
  • Patent number: 7053584
    Abstract: Disclosed is a driving device for a motor such as a stepping motor etc. for controlling an angle and a speed of the motor, wherein the driving device comprises exciting current detectors for detecting exciting currents of motor windings of the motor, an exciting current amplitude computation means for computing an exciting current amplitude value or the square of the exciting current amplitude value from exciting current detection values detected by the exciting current detectors, and a voltage impression unit for impressing voltages at values corresponding to a deviation value of the exciting current amplitude value and the current amplitude command or a deviation value of the square of the exciting current amplitude value and the square of the current amplitude command to the motor windings.
    Type: Grant
    Filed: October 1, 2003
    Date of Patent: May 30, 2006
    Assignee: Japan Servo.Co., Ltd.
    Inventors: Hiroaki Taka, Yoshifumi Kuwano, Akio Takemori, Yukinari Takahashi
  • Patent number: 7049785
    Abstract: An apparatus and method of controlling a stepper motor, includes a torque calculator to calculate torque operated on the stepper motor and to output to a controller a driving current setting signal corresponding thereto. The controller outputs to a driver a control signal to apply variable driving current based on the driving current setting signal to the stepper motor. The driver drives the stepper motor based on the control signal inputted from the controller. Accordingly, overheating and inaccurate operations of a control IC (the controller) and the stepper motor may be prevented, and driving characteristics such as low power consumption, low vibration and low noise of the stepper motor may be improved.
    Type: Grant
    Filed: June 24, 2003
    Date of Patent: May 23, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Suk-gyun Han
  • Patent number: 7046604
    Abstract: Herein disclosed is a optical disc driving apparatus for driving an optical disc having a central axis, comprising: a turntable having a central axis, said turntable being adapted to retain an optical disc under the condition that said central axis of said turntable is axially aligned with said central axis of said optical disc; an optical pickup unit movable toward and away from said central axis of said turntable, said optical pickup unit being adapted to write or retrieve information from said optical disc retained by said turntable; a stepping motor having a plurality of coils; a detecting unit for detecting an exterior vibration while being vibrated in response to said exterior vibration; a driver IC for controlling said stepping motor to have said stepping motor assume two different operation states consisting of a first operation state to drive said stepping motor to ensure that said optical pickup unit is moved toward and away from said central axis of said turntable, and a second operation state to d
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: May 16, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Takaharu Shigeta, Hiroki Kobayashi
  • Patent number: 7034495
    Abstract: An output port open control device (65) allows a port (P3) which outputs PWM signals of a Cos+ side to be in a high impedance state in a period in which respective PWM signals of Cos+ and Cos? supplied to a S-phase coil (22) of a stepping motor (2) are in a ground level, induced voltage corresponding to a magnetic flux variation caused in accordance with rotation of a magnet rotor (23) is generated in the S-phase coil (22), a voltage comparator (72) compares the induced voltage with a previously set threshold value and outputs presence or absence of the induced voltage, and a zero-reset judging device (66) determines that a pointer (4) is in the middle of rotation when the induced voltage is detected, and determines that the pointer (4) is in contact with a stopper mechanism (5) when it is not detected.
    Type: Grant
    Filed: October 28, 2004
    Date of Patent: April 25, 2006
    Assignee: Calsonic Kansei Corporation
    Inventor: Kiyoshi Sasaki
  • Patent number: 7034496
    Abstract: A method of correcting a pointing position of a pointer rotated by a stepper motor includes the steps of: performing a prereset operation in which the pointer is rotated to a reset operation starting position that represents a pointing position of the pointer which is shifted by a predetermined amount in a plus direction of a scale from a reset position where a pin which is rotated in conjunction with a rotation of the pointer abuts against a fixed stopper; after the prereset operation, performing a reset operation in which the pointer is rotated in a minus direction of the scale to the reset position; and after the reset operation, performing a correcting operation in which the pointer is rotated in the plus direction up to a reference pointing position which is indicated by previously stored reference pointing positional information.
    Type: Grant
    Filed: October 6, 2004
    Date of Patent: April 25, 2006
    Assignee: Yazaki Corporation
    Inventor: Masaki Oishi
  • Patent number: 7030584
    Abstract: A control circuit is described in which a single input terminal receives digital control signals and analog control signals. A circuit coupled to the single input provides a first output to indicate that a signal at said single input terminal is a digital signal and a second output indicates that a signal at said single input terminal is an analog signal.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: April 18, 2006
    Assignee: Andigilog, Inc.
    Inventor: Jade H. Alberkrack
  • Patent number: 7030587
    Abstract: A system for controlling a switch reluctance machine is provided. The system includes multiple phases located in the switch reluctance machine, each phase having multiple machine coils. Each machine coil is independently connected to a positive side switch circuit and a negative side switch circuit. Each positive side switch circuit is in electrical parallel connection with the other positive side switch circuits, and configured to control the flow of current through the machine coil to which it is connected. Similarly, the negative side switch circuits are connected in electrical parallel and configured to control the flow of current through the machine coil to which they are connected. The positive side and negative side switch circuits may be provided in a buck boost configuration or two half bridge configurations.
    Type: Grant
    Filed: April 9, 2004
    Date of Patent: April 18, 2006
    Assignee: Visteon Global Technologies, Inc.
    Inventors: Mohammad N. Anwar, Mehrdad Teimor, Daryl A. Wilson, Paul F. Turnbull, William Turnbull
  • Patent number: 7026781
    Abstract: A stepping motor driving system includes: a stepping motor that rotates at a predetermined angle according to a driving pulse signal, a vibration detector that detects vibration to output a vibration signal, and a stepping motor control unit that controls the driving pulse signal, which is applied to the stepping motor, to rotate the stepping motor at the predetermined angle. The driving pulse signal includes a start-up current which is required for rotating the stepping motor at a unit angle and a holding current which maintains a rotational angle of the stepping motor rotated by the start-up current. The stepping motor control unit changes the level of the holding current according to the vibration signal which is outputted from the vibration detector.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: April 11, 2006
    Assignee: Pioneer Corporation
    Inventors: Hitoshi Yamazaki, Takeshi Nishimura, Akira Yasaki, Hideki Kinoshita, Shigeru Kojima, Jun Togashi
  • Patent number: 7023165
    Abstract: A stepping motor control apparatus in accordance with the present invention comprises: a current detection unit that detects phase currents flowing into a stepping motor; an equivalent model-of-motor arithmetic unit that includes a coefficient multiplication block which performs multiplication using a coefficient ka?=Ts/? as a multiplier, a coefficient multiplication block which performs multiplication using a coefficient kb?=?/(Ts+?) as a multiplier, and a coefficient multiplication block which performs multiplication using a coefficient kg?=I0/E0 as a multiplier, and that calculates an estimated angle of excitation; a current control unit that controls an exciting current on the basis of the estimated angle of excitation, an angle command, and the phase currents detected by the current detection unit; and a variable voltage inverter that applies phase voltages to phase windings included in the stepping motor according to outputs of the current control unit.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: April 4, 2006
    Assignee: Japan Servo Co., Ltd.
    Inventors: Yoshifumi Kuwano, Hiroaki Taka, Akio Takemori
  • Patent number: 7023157
    Abstract: The reference signal generation unit 110a integrates, in the integration circuit 3, a staircase signal generated by the staircase generation unit 2, and thereby generates a reference signal VCTA whose signal level changes continuously over time, and which represents a limit value for the supply current. According to the control of the PWM control unit 120a, the bridge rectification circuit 130a maintains the coil supply current at the limit value, using a current chopper method. Additionally, when the current supply is stopped, the bridge rectification circuit 130a performs synchronous rectification, where the transistors 10 and 12 are brought into conduction, and a regenerative current is circulated in a closed circuit formed with the coil 19a. When the reference signal VCTA decreases relatively fast, the synchronous rectification prohibition unit 115a prohibits one of the transistors 10 and 12 from being brought into conduction when the current supply is stopped.
    Type: Grant
    Filed: October 25, 2004
    Date of Patent: April 4, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shingo Fukamizu, Katsuhiro Onishi
  • Patent number: 7019484
    Abstract: A stepping motor driver according to the present invention includes a torque component current calculating means for calculating a torque component current from phase currents and a rotor rotation angle, an absolute value converting means for obtaining an absolute value of the torque component current, a high speed-response judging means adapted for outputting a first control signal when a speed deviation between a command speed and a rotor speed is not more than a reference level, and outputting a second control signal when the speed deviation exceeds the reference level, and a current command outputting means adapted for outputting a current command according to the absolute value of the torque component current when the first control signal is outputted, and outputting a maximum current command value as the current command when the second control signal is outputted.
    Type: Grant
    Filed: March 29, 2005
    Date of Patent: March 28, 2006
    Assignee: Japan Servo Co., Ltd.
    Inventors: Akio Takemori, Yoshifumi Kuwano, Hiroaki Taka
  • Patent number: 7009824
    Abstract: An actuator, operated by being supplied with electric power, needs an initial setting for performing a desired operation by recognizing its starting position. The initial setting is conducted when an abnormality occurs in a signal which represents an operation of the actuator. The initial setting is also conducted when a system for the actuator recognizes a fact that a battery is electrically disconnected in association with information denoting a condition of the battery in a memory.
    Type: Grant
    Filed: June 20, 2003
    Date of Patent: March 7, 2006
    Assignee: DENSO Corporation
    Inventors: Tokuhisa Takeuchi, Takashi Takata
  • Patent number: 7005824
    Abstract: A shutter mechanism includes a drum (2), a stepping motor (5), a driver (20), a microcomputer (10), a memory (16), and a load magnitude detection circuit (30) that detects the magnitude of the load on the stepping motor (5) when an object such as a shutter (3) is either wound or unwound from the drum (2). The microcomputer (10) can set the upper and lower limit stopping positions of the shutter (3) by resetting the number of command pulses stored in the memory (16) when the load magnitude detection circuit (30) detects an increase in the load at the stepping motor (5), and storing the number of command pulses output to that point from the memory (16) when the load magnitude detection circuit (30) next detects an increase in the load at the stepping motor (5) after the outputting of the command pulses is next restarted.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: February 28, 2006
    Assignee: Minebea Co., Ltd.
    Inventor: Naotaka Akiwa
  • Patent number: 7002316
    Abstract: A drive for a vehicle HVAC vent door includes a drive transmission mounted within the shaft for the vent door. The drive transmission is of the sort commonly known as a wave drive transmission, wherein a lobed member is driven by an oblong drive shaft. The lobed member selectively drives an externally threaded flex ring that in turn engages an internally toothed drive transmission member. The internally toothed drive transmission member drives the shaft for the vent door. In this fashion, a relatively small motor is provided which has sufficient power to drive the vent door. Further, an electrical connection for supplying control signals is mounted at one end of the shaft and has a non-symmetrical configuration such that the motor and vent door will be properly orientated and relative to the vehicle.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: February 21, 2006
    Assignee: Air International (US) Inc.
    Inventor: Richard Hoyle
  • Patent number: 6998806
    Abstract: In the gaming machine, when the motor drive instruction to drive the motor occurs based on an instruction from an external, a constant voltage is applied to the motor and the motor is driven through the motor drive circuit 39. And when the excitation current value flowing in the motor becomes the first current value based on the constant voltage applied to the motor through the motor drive circuit 39, the voltage with on-time and off time is repeatedly applied to the motor through the motor drive circuit 39. Further, when the rotation speed of the motor becomes constant based on the voltage with on-time and off-time applied through the motor drive circuit 39, the constant voltage is applied to the motor based on the motor stop instruction through the motor drive circuit 39, thereby the motor is stopped.
    Type: Grant
    Filed: November 15, 2004
    Date of Patent: February 14, 2006
    Assignee: Aruze Corp.
    Inventor: Yuuichirou Suzuki
  • Patent number: 6992459
    Abstract: Stepping drive control of a motor is effected by synchronizing interruption to a CPU with N (in number) line triggers set to N times of one-line of an image. Further, in a synchronous mode in which phase control is effected in synchronous with N line triggers, acceleration/deceleration table can be switched not only by the N line triggers (external triggers) but also by internal triggers. With this arrangement, acceleration and deceleration of the motor is permitted within the N line triggers (external triggers) while being synchronized with the N line triggers (external triggers), thereby reducing a burden of software processing and realizing motor control corresponding to interruption of one line during high speed reading.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: January 31, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventor: Akitoshi Kikuchi
  • Patent number: 6989648
    Abstract: An electrical motor comprises a stator 1 and a rotor 2, the stator 1 having poles 3 facing circumferential surfaces of the rotor 2 so that the stator 1 forms a magnetic circuit with the rotor 2. The stator 1 further has stator windings 5 grouped into two or more phase windings A, B, which phase windings are separately energisable to induce stator magnetic fields which interact with magnetic fields associated with the rotor 2. A voltage across a stator phase winding is detected by voltage detecting means.
    Type: Grant
    Filed: January 11, 2001
    Date of Patent: January 24, 2006
    Assignee: The University of Leichester
    Inventors: Charles Pollock, John David Wale
  • Patent number: 6984956
    Abstract: A method of driving a step motor is provided which uses different operations of driving the step motor according to the driving speed of the driver, including a micro step operation for a low speed section of the driver and a full step operation for a high speed section of the driver. The method reduces low speed vibration and high speed noise caused by switching pulse noise. Moreover, driving the step motor by the full step operation in the high speed section reduces the frequency of use of a central processing unit (CPU), thereby stabilizing the driving device. In addition, only a small number of reduction gears is required, reducing the size of the driving device.
    Type: Grant
    Filed: October 16, 2002
    Date of Patent: January 10, 2006
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Kyung-pyo Kang, Hyoung-il Kim
  • Patent number: 6982815
    Abstract: An image reading apparatus has a scanner device and an ADF mounted to be openable/closable relative to a document glass which is located on the scanner device. The ADF has a conveying roller for conveying a document past the document glass. The scanner device has a carriage moved along the document glass to allow the scanning of the document set on the document glass and the reading of the image out of the document. Further, the image reading apparatus further has only one motor for driving the conveying roller and for moving the carriage, a clutch for the ADF which is switched to transmit a drive force of the motor to the conveying roller and a clutch for the scanner device which is switched to transmit a drive force of the motor to the carriage.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: January 3, 2006
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Tec Kabushiki Kaisha
    Inventor: Kazuyoshi Tsutsumi
  • Patent number: 6979973
    Abstract: An apparatus to and method of controlling a step motor by checking driving pulses to control the operation of the step motor and resetting the apparatus controlling the step motor when signals indicating an abnormal operation, such as stepping out, of the step motor are detected, thereby preventing a fire or damage to parts caused by the abnormal operation of the step motor.
    Type: Grant
    Filed: October 8, 2004
    Date of Patent: December 27, 2005
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Si-hun Yoo
  • Patent number: 6979972
    Abstract: A method for detecting a state of an electric motor includes: energizing the motor with electrical power such that an associated current applied to the electric motor rises over time toward a reference level; determining an amount of time that elapses between when the motor is energized and the reference level is reached; and, evaluating a state of the motor based upon the determined amount of time.
    Type: Grant
    Filed: December 30, 2003
    Date of Patent: December 27, 2005
    Assignee: Xerox Corporation
    Inventor: Kevin M. Carolan
  • Patent number: 6972876
    Abstract: The invention provides an image reading apparatus that produces a precise image of an original document to prevent the read image from having distortion or irregular density, by driving a DC motor, which drives an image reading unit in a scanning direction, at a constant speed suitable for a document to be read. In addition, the image reading apparatus prevents position errors or misalignment at the start of the image reading, or at a restart of the image reading after the image reading is paused. A speed control circuit provides feedback to a DC motor to synchronize a time interval detected by a pulse interval detecting circuit with a time interval set by an interval setting register, so that the DC motor is operated at a constant speed. A counter counts the number of signals output from an encoder. After the speed of the DC motor is stabilized, a timing of signals output from a CCD drive unit to the image reading unit is synchronized with a timing of the signals generated by the encoder.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: December 6, 2005
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Atsushi Yokochi
  • Patent number: 6967460
    Abstract: An error-correction method and apparatus are used for a step motor transmission system. The step motor has a plurality of inductor coils therein for rotating an internal shaft thereof. A rotational error gamma table is established by measuring an error value for each rotational step of the step motor. The error-correction apparatus receives an external digital displacement signal for producing a rotational step signal. A compensation current is produced according to the rotational step signal and an error value in the rotational error gamma table. The inductor coils are driven by the compensation current to rotate the internal shaft precisely.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: November 22, 2005
    Assignee: Service & Quality Technology Co., Ltd.
    Inventor: Ching-Tung Tseng
  • Patent number: 6956351
    Abstract: A driving device, includes a stepping motor having an exciting coil and a rotor; a driven member driven in accordance with a rotation of the rotor; a stopper mechanically stopping the driven member at a zero position; a controller controlling the state of excitation of the exciting coil; an induced voltage detector detecting an induced voltage generated by a change of magnetic flux according to the rotation of the rotor; and a zero position detector detecting a stoppage of the driven member at the zero position. The controller supplies an exciting pattern to the exciting coil at the time of processing of zero position detection. The exciting pattern includes a first exciting step for detecting the induced voltage and a second exciting step for rotation. Total periods of the first exciting step is greater than that of the second exciting step during an electrical angle 90° in the one cycle.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: October 18, 2005
    Assignee: Yazaki Corporation
    Inventor: Yoshihisa Yamada
  • Patent number: 6949907
    Abstract: An apparatus including a stepper motor for actuating a moveable element of the apparatus. The maximum torque that can be generated at each step is a function of the voltage supplied to the motor. In some applications, however, torque greater than the nominal maximum may be required for brief periods. Under such conditions, the need for greater torque is sensed and a controller supplies a higher voltage to the motor, thereby increasing temporarily the output torque. When increased torque is no longer required, the voltage is reduced to nominal. The invention is useful, for example, for extending the range of a stepper motor actuator for an intake air control valve in a fuel cell assembly.
    Type: Grant
    Filed: August 21, 2003
    Date of Patent: September 27, 2005
    Assignee: Delphi Technologies, Inc.
    Inventor: Charles R. DeJohn
  • Patent number: 6946814
    Abstract: A stepping motor driver comprises: an excitation angle generating means which generates an excitation angle from an external command pulse; a current control means which controls exciting currents for a stepping motor according to the excitation angle and a current command; a current detection means which detects phase currents of the stepping motor; an angle detection means which detects a rotor rotation angle of the stepping motor; a torque component current calculating means which calculates a torque component current from the phase currents and the rotor rotation angle; an absolute converting means which obtains the absolute value of the torque component current; and a current command output means which outputs the current command depending on the absolute value of the torque component current.
    Type: Grant
    Filed: September 17, 2004
    Date of Patent: September 20, 2005
    Assignee: Japan Servo Co., Ltd.
    Inventors: Akio Takemori, Yoshifumi Kuwano, Yukinari Takahashi, Hiroaki Taka
  • Patent number: 6946813
    Abstract: A step motor control device detects a rotational driving state of a step motor. In a first detection period immediately after termination of the rotational driving state of the step motor, selected switch elements are controlled so that a first detection signal is obtained. If the step motor is not in a rotational driving state, the first detection signal is suppressed to a low voltage that is equal to or lower than a threshold value. In a second detection period immediately after lapse of the first detection period, selected switch elements are controlled so that a second detection signal of high and stable voltage is obtained in accordance with the rotational driving state of the step motor.
    Type: Grant
    Filed: February 23, 2004
    Date of Patent: September 20, 2005
    Assignee: Seiko Instruments Inc.
    Inventor: Saburo Manaka
  • Patent number: 6943523
    Abstract: For self-switching control of a brushless motor (10) powered by means of a predetermined electrical cycle in order to cause the rotor to advance, the control system comprises an indicator device (100) for indicating the mechanical position of the rotor, the device being associated with a detector device (50) forming an incremental coder device (150) for encoding the mechanical position of the rotor. The system also comprises a motor control assembly made up of processor means (20) for processing the signals coding the mechanical position of the rotor connected to regulator means (30) for powering the plurality of stator windings. The device for indicating the mechanical position of the rotor comprises at least one series (101) of indications of the mechanical position of the rotor corresponding to passing through one electrical cycle of the stator, whereby the incremental coder device (150) delivers the processor means with one synchronization signal for each electrical cycle.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: September 13, 2005
    Assignee: MIDI Ingenierie
    Inventor: Jacques Feres