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: In a case where a position command path for a control position of a load 5 that is equivalent to a moving object is set by issuing a position command Rc(z), a gain for one of a high-frequency component, a specified frequency, and a specified frequency width is constrained. This means that a resonant frequency can be constrained, and that after the position command Rc(z) arrives at a target position, a position detection signal Y(z) can also arrive at the target position in a set number of steps. It is therefore possible to perform positioning at high speed and with high precision by constraining a resonance mode of a mechanism that includes the moving object, and a feed-forward control can be performed that meets target positioning times that are set for various types of operating patterns.

Abstract: In a case where a position command path for a control position of a load 5 that is equivalent to a moving object is set by issuing a position command Rc(z), a gain for one of a high-frequency component, a specified frequency, and a specified frequency width is constrained. This means that a resonant frequency can be constrained, and that after the position command Rc(z) arrives at a target position, a position detection signal Y(z) can also arrive at the target position in a set number of steps. It is therefore possible to perform positioning at high speed and with high precision by constraining a resonance mode of a mechanism that includes the moving object, and a feed-forward control can be performed that meets target positioning times that are set for various types of operating patterns.

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 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 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 controller for an optical scanner includes a mirror angle detecting unit for detecting an angle of a mirror, a rotation shaft angle detecting unit for detecting an angle of the shaft, a current detecting unit for detecting a current supplied to a motor, and a torsional vibration stabilizing compensation unit for stabilizing a torsional vibration of the shaft, thereby a value subjected to a proportional compensation and a differential compensation by using a rotation shaft angle detected value and a value from the torsional vibration stabilizing compensation unit are negatively fed back to a value obtained by integrally compensating for a tracking error between the angle desired value and a mirror angle detection value to determine a current value to be supplied to the motor.

Abstract: A controller for an optical scanner includes a mirror angle detecting unit for detecting an angle of a mirror, a rotation shaft angle detecting unit for detecting an angle of the shaft, a current detecting unit for detecting a current supplied to a motor, and a torsional vibration stabilizing compensation unit for stabilizing a torsional vibration of the shaft, thereby a value subjected to a proportional compensation and a differential compensation by using a rotation shaft angle detected value and a value from the torsional vibration stabilizing compensation unit are negatively fed back to a value obtained by integrally compensating for a tracking error between the angle desired value and a mirror angle detection value to determine a current value to be supplied to the motor.

Abstract: A magnetic disk apparatus for recording information on and reproducing information from a magnetic disk with a magnetic head. A magnetic head supporting device includes a slider having the magnetic head mounted thereon, a flexible section supporting the slider, and a supporting section connected to the flexible section. The slider, the flexible section, and the supporting section are integrally formed from a same material. A rotary-type or linear-type positioning mechanism positions the magnetic head at a predetermined radial position of the magnetic disk.

Abstract: Magnetic disk unit 1 is connected to personal computer 400 through recording mode selecting means 2, and recording mode selecting means 2 can select one of 3 recording modes (high reliability, large capacity, and high speed) and magnetic disk unit 1 records information with the recording method selected by recording mode selecting means 2. The controllability of the magnetic disk unit 1 and personal computer 400 is improved significantly by selecting the most suitable recording method according to the characteristics of information to be recorded.

Abstract: A rotary information recording/reproducing apparatus has a carriage rotatable by the first and second driving coils about an axis that moves an information recording/reproducing head radially to an associated recording disk for head positioning relative to the disk. The angle between a line connecting the center of the first driving coil and the center of the carriage pivot shaft and a line connecting the head and the center of the carriage pivot shaft is set to be not greater than 90 degrees while the angle formed between the first and second driving coils about the center of the carriage pivot shaft is within the range of from 100 degrees to 150 degrees, whereby reduction in the size and thickness of the apparatus can be achieved. A magnet-yoke assembly, which is subject to a reaction force, is mounted to a base by sheet springs and reaction-force damping members interposed therebetween so that the magnet-yoke assembly is independent from and infinitesimally rotatable relative to the base.

Abstract: A disk apparatus has a gain identifying apparatus for identifying a gain from a control signal for controlling each head to a detection position signal, a memory device to store the identified gain, and an apparatus for correcting the control signal on the basis of the gain at at time point when each head which is provided for each recording surface of disks is located at each of a plurality of track positions.

Abstract: A magnetic disk unit comprising a one-piece carriage structure having a small thermal off-tracking amount, with the carriage structure including a rotary shaft; guide arms integrally supported on a guide-arm retainer at their proximal ends and extending independently and parallely; bearing retainers formed on both ends of the guide-arm retainer; and bearings fixed on the bearing retainers rotatably connecting the guide-arm retainer to the rotary shaft. A center line in a direction of thickness of the outermost guide arm is located outside of that of the bearing in a direction of height thereof, and a concave portion is continuously formed on the bearing retainer. Thermal coefficients of expansion of the guide arms and the guide-arm retainer are substantially equal, with the carriage structure being fashioned of an alloy mainly containing Al and Si, eutectic crystal Si particles in the guide arm and/or the guide-arm retainer. The average value of the longest eutectic crystal Si particles therein is 1.6 .mu.

Abstract: A disk drive has a data recording medium disk, a head disposed facing a recording surface of the disk, for reading and writing data, a positioning mechanism for supporting and moving the head, a position detector for detecting the position of the head and outputting a position detection signal, and a control unit for processing the position detection signal and outputting a position control signal to the positioning mechanism.

Abstract: A magnetic disk system utilizes both of voice coil motor and a piezoelectric element provided on a head supporting arm to precisely position a head to a predetermined position on a disk. The piezoelectric element is built in the distal end portion of the head supporting arm and is restricted in respect of its movement by a resilient mechanism which has low rigidity in the driving direction of the piezoelectric element and high rigidity in the other directions. The resilient mechanism is formed by pairs of doubled parallel leaf springs so arranged that each pair is disposed on either side of the piezoelectric element.

Abstract: Method and apparatus for control of positioning of a recording/playback head or other controlled object. When a controlled object reaches the vicinity of a target position, the control system is switched from operation as a velocity control system to operation as a position control system. By using state variables of the controlled object at that time, coefficients corresponding to the detected state variables are determined from characteristics of the controlled object which are determined in advance. By using the determined coefficient values, initial values upon start of position control of the position control system are set, and positioning control is then carried out.

Abstract: A sample moving apparatus for positioning wafers with high accuracy, which apparatus comprises a fine adjustment actuator having a drive stroke to finely move the wafer, a fine adjustment stage driven by the fine adjustment actuator, a coarse adjustment actuator having a drive stroke to relatively coarsely move the wafer, a coarse adjustment stage driven by the coarse adjustment actuator, and a holder arrangement for attractively holding the wafer onto the wafer bearing surfaces of the respective stages. Upon selective energization of the holder arrangement of the respective stages, the wafer is moved while being attracted to the coarse adjustment stage or while being attracted to the coarse adjustment stage.

Abstract: A vibrating-type driving unit employing a piezo-electric device is provided for conveying an object such as a sheet material. A follower roller is provided to be opposed to the vibrating-type driving unit, and A.C. power is supplied thereto so as to convey the object. In addition, a friction coefficient of surface of the follower roller is selected to be greater than friction coefficient of a driving head of the vibrating-type driving unit. With this selection, it is possible to convey the object efficiently and stably.