Abstract: A galvanoscanner including: a rotor including a shaft as a rotational center, and permanent magnets disposed around the shaft and polarized to a plurality of poles in a circumferential direction of the shaft; and a stator disposed in the outside of the rotor through a clearance and including coils, a yoke, and an outer casing so that the rotor swings in a predetermined angle range; wherein: the permanent magnets are provided with grooves which are formed in a direction of the rotation shaft so as to straddle circumferentially adjacent magnetic poles of the permanent magnets; and the permanent magnets are parted into at least two parts per pole by parting lines. Thus, the ratio of the torque constant to the moment of inertia can be improved so that the current required for driving can be reduced and reduction of power consumption at driving time can be attained.

Abstract: A galvanoscanner including: a rotor including a shaft as a rotational center, and permanent magnets disposed around the shaft and polarized to a plurality of poles in a circumferential direction of the shaft; and a stator disposed in the outside of the rotor through a clearance and including coils, a yoke, and an outer casing so that the rotor swings in a predetermined angle range; wherein: the permanent magnets are provided with grooves which are formed in a direction of the rotation shaft so as to straddle circumferentially adjacent magnetic poles of the permanent magnets; and the permanent magnets are parted into at least two parts per pole by parting lines. Thus, the ratio of the torque constant to the moment of inertia can be improved so that the current required for driving can be reduced and reduction of power consumption at driving time can be attained.

Abstract: A positioning control system for positioning a moving element on a basis of position command data is provided with a feedback loop. The system is also provided with a loop gain modifier for determining a loop gain, which is to be used in a following positioning operation, on a basis of a difference between an amount of overshoot measured in a current positioning operation and a predetermined tolerance or on a basis of a difference between an amount of overshoot measured in a current positioning operation and a first predetermined tolerance and a difference between an amount of undershoot measured in the current positioning operation and a second predetermined tolerance. The first and second tolerances may preferably be the same in absolute value. The moving element may specifically be a steerable mirror for drilling holes in a work by reflecting a laser beam. Also disclosed is a laser drilling machine including the system.

Abstract: A galvanoscanner including: a rotor including a shaft as a rotational center, and permanent magnets disposed around the shaft and polarized to a plurality of poles in a circumferential direction of the shaft; and a stator disposed in the outside of the rotor through a clearance and including coils, a yoke, and an outer casing so that the rotor swings in a predetermined angle range; wherein: the permanent magnets are provided with grooves which are formed in a direction of the rotation shaft so as to straddle circumferentially adjacent magnetic poles of the permanent magnets; and the permanent magnets are parted into at least two parts per pole by parting lines. Thus, the ratio of the torque constant to the moment of inertia can be improved so that the current required for driving can be reduced and reduction of power consumption at driving time can be attained.

Abstract: A galvanoscanner including: a rotor including a shaft as a rotational center, and permanent magnets disposed around the shaft and polarized to a plurality of poles in a circumferential direction of the shaft; and a stator disposed in the outside of the rotor through a clearance and including coils, a yoke, and an outer casing so that the rotor swings in a predetermined angle range; wherein: the permanent magnets are provided with grooves which are formed in a direction of the rotation shaft so as to straddle circumferentially adjacent magnetic poles of the permanent magnets; and the permanent magnets are parted into at least two parts per pole by parting lines. Thus, the ratio of the torque constant to the moment of inertia can be improved so that the current required for driving can be reduced and reduction of power consumption at driving time can be attained.

Abstract: A galvanoscanner including: a rotor including a shaft as a rotational center, and permanent magnets disposed around the shaft and polarized to a plurality of poles in a circumferential direction of the shaft; and a stator disposed in the outside of the rotor through a clearance and including coils, a yoke, and an outer casing so that the rotor swings in a predetermined angle range; wherein: the permanent magnets are provided with grooves which are formed in a direction of the rotation shaft so as to straddle circumferentially adjacent magnetic poles of the permanent magnets; and the permanent magnets are parted into at least two parts per pole by parting lines. Thus, the ratio of the torque constant to the moment of inertia can be improved so that the current required for driving can be reduced and reduction of power consumption at driving time can be attained.

Abstract: A galvanoscanner including: a rotor including a shaft as a rotational center, and permanent magnets disposed around the shaft and polarized to a plurality of poles in a circumferential direction of the shaft; and a stator disposed in the outside of the rotor through a clearance and including coils, a yoke, and an outer casing so that the rotor swings in a predetermined angle range; wherein: the permanent magnets are provided with grooves which are formed in a direction of the rotation shaft so as to straddle circumferentially adjacent magnetic poles of the permanent magnets; and the permanent magnets are parted into at least two parts per pole by parting lines. Thus, the ratio of the torque constant to the moment of inertia can be improved so that the current required for driving can be reduced and reduction of power consumption at driving time can be attained.

Abstract: A difference between each position command data outputted in a form of a step signal from a high-level controller and its corresponding detected position data of a movable body is integrated by an integral compensator to position the movable body. Assuming, for example, that the movable body is a steerable mirror, digital filters are arranged to compensate the value of an initial state of an angular displacement and the value of an initial state of an angular velocity, respectively, and respective impulse responses of the digital filters as additional input elements are added to an output terminal of the integral compensator. For higher effectiveness, internal state variables of the digital filters can desirably be cleared to zero whenever an angle (position) command data is received.

Abstract: A rocking actuator and a laser machining apparatus which can suppress a temperature rise of a permanent magnet in a moving-magnet actuator. Even when a steerable mirror is positioned by rapid and continuous motions, highly reliable machining can be performed without degrading machining throughput or hole position accuracy. A cooling jacket for cooling a casing and heat transfer units brought into contact with a coil and the casing are provided. Heat generated in the coil is introduced to the casing through the heat transfer bypass units. Thus, the temperature rise of the coil is suppressed. Radial grooves are provided in the permanent magnet opposed to the coil so as to prevent an eddy current from appearing therein. Groove depth is made not smaller than skin depth expressed by a function of volume resistivity and permeability of the permanent magnet and a fundamental frequency of a current applied to the coil.

Abstract: A scanner has a rotor, and a stator disposed in the outside of the rotor. The rotor includes a shaft, and a permanent magnet mounted on the outer circumferential side of the shaft. The stator includes a casing, a yoke held in the inner circumferential side of the casing, and coils disposed in the inner circumferential side of the yoke. The permanent magnet of the rotor has radially depressed grooves formed in its outer circumferential portion. The torque constant of the scanner is circumferentially equalized by the grooves.

Abstract: A digital servo control unit which uses a D/A converter, which suppresses the spike-like pulsation superimposed on a current error signal inside a current control circuit, and which has control performance not lower than that in the background art even when a low-voltage and low-price power supply circuit is used. A first-order low pass filter acts on an analog signal output by the D/A converter, and a stabilizing compensation occurs for a phase delay caused by the first-order low pass filter. The first-order low pass filter is formed as a low pass filter having a cut-off frequency which is lower than a sampling frequency. The first-order low pass filter may be replaced by a notch filter having a cut-off frequency which is equal to a sampling frequency or which is equal to an integer multiple of a Nyquist frequency.

Abstract: A scanner system includes a servo control unit. A rotation angle of a rotating shaft supporting a mirror is detected, and an error of the detected value with respect to a commanded value is integrated by an integral compensator so that the detected value is able to track the commanded value. A tracking error proportional compensator is disposed in parallel with the integral compensator so as to add a correction value proportional to the error to the integrated value of the error. A plurality of gains are prepared for each of the integral compensator, the tracking error proportional compensator, a detected value proportional compensator and a detected value differential compensator of the servo control unit. Each gain is changed in accordance with a travel angle of the commanded value. Thus, the mirror can be positioned quickly so that the machining speed can be improved.

Abstract: A rocking actuator and a laser machining apparatus which can suppress a temperature rise of a permanent magnet in a moving-magnet actuator. Even when a steerable mirror is positioned by rapid and continuous motions, highly reliable machining can be performed without degrading machining throughput or hole position accuracy. A cooling jacket for cooling a casing and heat transfer units brought into contact with a coil and the casing are provided. Heat generated in the coil is introduced to the casing through the heat transfer bypass units. Thus, the temperature rise of the coil is suppressed. Radial grooves are provided in the permanent magnet opposed to the coil so as to prevent an eddy current from appearing therein. Groove depth is made not smaller than skin depth expressed by a function of volume resistivity and permeability of the permanent magnet and a fundamental frequency of a current applied to the coil.

Abstract: A positioning control system for positioning a moving element on a basis of position command data is provided with a feedback loop. The system is also provided with a loop gain modifier for determining a loop gain, which is to be used in a following positioning operation, on a basis of a difference between an amount of overshoot measured in a current positioning operation and a predetermined tolerance or on a basis of a difference between an amount of overshoot measured in a current positioning operation and a first predetermined tolerance and a difference between an amount of undershoot measured in the current positioning operation and a second predetermined tolerance. The first and second tolerances may preferably be the same in absolute value. The moving element may specifically be a steerable mirror for drilling holes in a work by reflecting a laser beam. Also disclosed is a laser drilling machine including the system.

Abstract: A optical scanner control method and a optical scanner capable of positioning a mirror at a high speed independently of a rocking angle, and a laser machining apparatus for irradiating a printed circuit board with a laser beam by use of the optical scanner to thereby perforate the printed circuit board. In order to operate an actuator for rocking the mirror based on a deviation of a current position from an commanded value, a change in gain of the actuator is measured in accordance with each rocking angle in advance, and the manipulated variable of the actuator is corrected to cancel the change in gain. Thus, the influence of the alteration of a torque constant in accordance with the rocking angle can be suppressed so that the response characteristic becomes uniform all over a scanning region, and the positioning speed can be improved.

Abstract: A scanner has a rotor, and a stator disposed in the outside of the rotor. The rotor includes a shaft, and a permanent magnet mounted on the outer circumferential side of the shaft. The stator includes a casing, a yoke held in the inner circumferential side of the casing, and coils disposed in the inner circumferential side of the yoke. The permanent magnet of the rotor has radially depressed grooves formed in its outer circumferential portion. The torque constant of the scanner is circumferentially equalized by the grooves. Thus, positioning accuracy is improved.

Abstract: There is provided a digital servo control unit which uses a D/A converter, which suppresses the spike-like pulsation superimposed on a current error signal inside a current control circuit, and which has control performance not lower than that in the background art even when a low-voltage and low-price power supply circuit is used. The digital servo control unit has a first-order low pass filter acting on an analog signal output by the D/A converter, and a stabilizing compensation means for compensating a phase delay caused by the first-order low pass filter. An output signal of the first-order low pass filter is input to a current control circuit as a current command signal. The first-order low pass filter is formed as a low pass filter having a cut-off frequency which is lower than a sampling frequency. The first-order low pass filter may be replaced by a notch filter having a cut-off frequency which is equal to a sampling frequency or which is equal to an integer multiple of a Nyquist frequency.

Abstract: An optical scanner which can realize target trajectory tracking machining at a high speed and with a high accuracy. In a servo control circuit controlling the operation of an X-axis scanner for positioning a mirror and the operation of a Y-axis scanner for positioning another mirror, sine wave response is performed at a specific frequency on feedback control for each axis so that the gain characteristic and the phase characteristic of the feedback control are estimated. This arithmetic operation processing is performed by a microprocessor prior to machining, and the results of estimation of the two axes are stored as data for each frequency. In the stage of machining, the results of estimation in terms of the gain characteristic and the phase characteristic are used for correcting the amplitude and phase of a sine wave of a target trajectory in order to cancel each characteristic.

Abstract: A difference between each position command data outputted in a form of a step signal from a high-level controller and its corresponding detected position data of a movable body is integrated by an integral compensator to position the movable body. Assuming, for example, that the movable body is a steerable mirror, digital filters are arranged to compensate the value of an initial state of an angular displacement and the value of an initial state of an angular velocity, respectively, and respective impulse responses of the digital filters as additional input elements are added to an output terminal of the integral compensator. For higher effectiveness, internal state variables of the digital filters can desirably be cleared to zero whenever an angle (position) command data is received.

Abstract: A optical scanner control method and a optical scanner capable of positioning a mirror at a high speed independently of a rocking angle, and a laser machining apparatus for irradiating a printed circuit board with a laser beam by use of the optical scanner to thereby perforate the printed circuit board. In order to operate an actuator for rocking the mirror based on a deviation of a current position from an commanded value, a change in gain of the actuator is measured in accordance with each rocking angle in advance, and the manipulated variable of the actuator is corrected to cancel the change in gain. Thus, the influence of the alteration of a torque constant in accordance with the rocking angle can be suppressed so that the response characteristic becomes uniform all over a scanning region, and the positioning speed can be improved.