According to one embodiment, a controller of a stepping motor includes a table generating unit and a current controlling unit. The table generating unit generates a data table of a threshold by using values of induced voltage at frequencies of switching signal that changes a set value of a drive current, the threshold being proportional to a frequency of the switching signal within an operation region in which the frequency of the switching signal is lower than a predetermined frequency, the values of the induced voltage including a first induced voltage generated at a first frequency of the switching signal and a second induced voltage generated at a second frequency of the switching signal. The current controlling unit controls a value of the drive current in accordance with a comparison result between the threshold and an induced voltage that is detected at a frequency lower than the predetermined frequency.

The task of the present invention is to provide a driving circuit capable of outputting information useful to design or control of a system to outside. The present invention relates to a driving circuit and a driving method of a stepping motor, and an electronic machine using the driving circuit of a stepping motor. A counter electromotive force detection circuit detects a counter EMF generated in a coil. A revolution count detection circuit acquires the revolution count of the stepping motor. A load angle estimating portion calculates a load angle according to the counter EMF and the revolution count. An interface circuit is configured to be capable of outputting angle information associated with the load angle to outside, or accessing the angle information from the outside.

The task of the present invention is to provide a driving circuit capable of outputting information useful to design or control of a system to outside. The present invention relates to a driving circuit and a driving method of a stepping motor, and an electronic machine using the driving circuit of a stepping motor. A counter electromotive force detection circuit detects a counter EMF generated in a coil. A revolution count detection circuit acquires the revolution count of the stepping motor. A load angle estimating portion calculates a load angle according to the counter EMF and the revolution count. An interface circuit is configured to be capable of outputting angle information associated with the load angle to outside, or accessing the angle information from the outside.

The present invention optimizes a current setting value within a short time. The present invention relates to a driving circuit and a driving method for a stepping motor, and an electronic machine using the same. A current value setting circuit generates a current setting value. A constant current chopper circuit generates a pulse modulation signal, which pulse-width modulates by way of having a detection value of a coil current flowing through a coil approach close to the current setting value. A logic circuit controls a bridge circuit connected to a coil of a stepping motor according to the Pulse modulation signal. The current value setting circuit sets the current setting value to a predetermined full-torque setting value in a first period after rotation starts, reduces the current setting value by a predetermined method to a predetermined second setting value less than the first setting value in the following second period, and switches to a high-efficiency mode and adjusts the current setting value by means of feedback control.

The present invention optimizes a current setting value within a short time. The present invention relates to a driving circuit and a driving method for a stepping motor, and an electronic machine using the same. A current value setting circuit generates a current setting value. A constant current chopper circuit generates a pulse modulation signal, which pulse-width modulates by way of having a detection value of a coil current flowing through a coil approach close to the current setting value. A logic circuit controls a bridge circuit connected to a coil of a stepping motor according to the Pulse modulation signal. The current value setting circuit sets the current setting value to a predetermined full-torque setting value in a first period after rotation starts, reduces the current setting value by a predetermined method to a predetermined second setting value less than the first setting value in the following second period, and switches to a high-efficiency mode and adjusts the current setting value by means of feedback control.

A motor control circuit includes an input voltage measuring unit, a temperature measuring unit, a speed setting unit, and a speed control unit. The input voltage measuring unit measures an input voltage input to a motor control device. The temperature measuring unit measures the temperature. The speed setting unit sets a target value of driving speed of a stepping motor based on a measurement result of the input voltage measuring unit, a measurement result of the temperature measuring unit and based on a set value of driving speed preset for each of the plural partial areas which are sectioned in a matrix form with a threshold value related to the input voltage and a threshold value related to the temperature. The speed control unit controls the driving speed according to the target value of the driving speed set in the speed setting unit.

A drive device used in a head-up display device, the drive device being accommodated in a housing of the head-up display device and being fixed to the housing. The drive device includes a motor having a rotation shaft and a motor case having an end face through which the rotation shaft is protruded, a vibration suppressing member, and a frame provided with a first plate part having a through hole and a second plate part extended from the first plate part. The motor is fixed to the first plate part in a state that the rotation shaft is penetrated through the through hole and the end face is contacted with the first plate part, the vibration suppressing member is fixed to the first plate part or the motor case, and the second plate part is provided with a frame side fixed part which is to be fixed to the housing.

A drive device used in a head-up display device, the drive device being accommodated in a housing of the head-up display device and being fixed to the housing. The drive device includes a motor having a rotation shaft and a motor case having an end face through which the rotation shaft is protruded, a vibration suppressing member, and a frame provided with a first plate part having a through hole and a second plate part extended from the first plate part. The motor is fixed to the first plate part in a state that the rotation shaft is penetrated through the through hole and the end face is contacted with the first plate part, the vibration suppressing member is fixed to the first plate part or the motor case, and the second plate part is provided with a frame side fixed part which is to be fixed to the housing.

A control device for controlling a stepping motor includes at least one processor which function as a control unit configured to control the stepping motor through a first control method or a second control method by using a control signal, wherein the memory configured to store a plurality of locus data indicating a relationship between an advance angle and a rotation speed of the stepping motor at each waveform of the control signal, the advance angle being a phase difference between a phase corresponding to a rotation position of the stepping motor and a phase of the control signal, and wherein the control unit select one piece of locus data from the plurality of locus data stored in the memory before switching a control method between the first control method and the second control method.

A positioning drive has a first stepper drive unit having a first stepper drive controller and a first stepper motor, and a second stepper drive unit having a second stepper drive controller and a second stepper drive. The two stepper drives and the power take-off element are force-coupled and drive-coupled by a mechanical coupling unit. A central unit controls the two stepper drive controllers by a control signal, in each instance. The control signals predetermine the stator reference field angle and the rotor reference field angle set by the stepper drive controller. The central unit has an overriding regulator for the position of the power take-off element, and a subordinate regulator for setting a tensioning moment for each stepper motor. The tensioning moments occur by setting a load actual angle at the stepper drive.