Abstract: Two all pass filters (11, 12) with 90° phase-shifted different center frequencies are employed to pass an alternating signal S with jitters in the period to generate signals S1 and S2, 90° phase-shifted from each other. A pulse generator (22) generates a sampling pulse Sp by detecting a zero cross point of the phase-shifted signal S2. A full-wave rectifier (21) rectifies full waves of the phase-shifted signal S1 and provides a rectified output to a sampling circuit (23), which extracts a peak value of the amplitude at the timing of the sampling pulse Sp.

Abstract: A stylus structure (40) integrally incorporating a stylus (2), a vibrator (4), a detector (6), a first secondary magnetic circuit (12) and a second primary magnetic circuit (21), and a stylus support (30) integrally incorporating a first primary magnetic circuit (11) and a second secondary magnetic circuit (22) are mutually fittable, thereby achieving signal transmission by the respective magnetic circuits using no electrical contact.

Abstract: A reference space includes a plurality of reference graphics. An image space is obtained by imaging the reference space. Affine transformation series are determined from the reference and image spaces for transcribing graphic cores of imaged graphics on graphic cores of reference graphics. If an affine-transformed positional error falls outside a tolerance, the reference space is divided into sub-spaces. Affine transformations and space divisions are repeated for out-of-tolerance sub-spaces until their estimations of distortion finally fall inside the tolerance.

Abstract: An interference optical system (18) leads parallel beam to a pair of opposed test surface (M1, M2). It then leads, from the test surfaces via different optical paths (C1, C2), interference fringe images formed by radiation of the parallel beam to the test surfaces (M1, M2), respectively. The interference optical system (18) has a pair of opposite reference surfaces (S1, S2) formed thereon and defined with a highly accuracy parallelism and distance. A measurement head (27) is provided with these reference surfaces (S1, S2), which are interposed between and oppose to the test surfaces (M1, M2), respectively. Imaging devices (19a, 20a) take interference fringe images that are created through interference between a light reflected at each of the test surfaces (M1, M2) and a light reflected at the corresponding reference surface (S1, S2) opposing thereto.

Abstract: A fine feed mechanism (50) and a coarse feed mechanism (60) respectively for minutely and greatly displacing a stylus (12) is provided to a microscopic geometry measuring device (1), so that the respective mechanisms (50, 60) are combinedly actuated for easily controlling the movement of the stylus (12) in a wide range at a short time. Further, a movable balancing portion (53) moving in a direction opposite to a movable driving portion (52) is provided to the fine feed mechanism (50). Since a reaction force caused by the movement of the movable driving portion (52) is cancelled by another reaction force caused by the movement of the movable balancing portion (53) at a fixed portion (51), no mechanical interference is caused between the respective mechanisms (50, 60), thus accurately controlling the movement of the stylus (12).

Abstract: A part of the output light from a semiconductor laser (1), which has a wavelength controllably variable with an injection current, is split at a beam splitter (3) and introduced into a interference optical system (5). In order to vary an optical path length difference between two light beams in the interference optical system (5) to modulate interference fringes to be obtained, AOMs (55, 56) are arranged on the two split optical paths and an EOM (56) on one of them. The interference fringes obtained from the interference optical system (5) are received at a photoreceptive device (7), and from the received signal, the phase is detected by a phase detector (8) and the phase amplitude is detected by an amplitude extractor (9). In order to stabilize the wavelength, a controller (10) feedback controls the injection current to the semiconductor laser (1) so that the phase amplitude matches to a predetermined setting.

Abstract: A surface configuration measuring method is provided, the surface configuration measuring method being characterized in having the steps of: moving a touch signal probe by a command velocity vector to touch a surface of the workpiece to be measured; scanning the surface of the workpiece to be measured, the touch signal probe being moved along the surface to be measured while controlling the distance relative to the surface to be measured so that detected amplitude value of a detection signal outputted by the detecting circuit becomes a predetermined reference value, thus outputting the detected amplitude value and corresponding measuring position; and calculating an estimated surface position based on the detected amplitude value and the measuring position estimated to be obtained when surface is scanned to keep the detected amplitude value constant.

Abstract: A capacitive distance sensor adapted to measure a distance between an object and the sensor device, which is suitable for determining surface configuration of an object includes a objective electrode, moving device for the objective electrode and a detecting means of moving distance of the objective electrode. The moving device is controlled depending on the signal from the objective electrode to position it in a predetermined range of clearance. The distance between the object and the sensor device is calculated based on the signals from the detecting means and the objective electrode.

Abstract: A movement control mechanism of contact-type vibrating probe is provided, where the contact-type vibrating probe can be used as a probe for profiling measurement and continuous measurement and configuration of a workpiece can be measured with high accuracy. The movement control mechanism for controlling movement of a support body (23) which moves a contact-type vibrating probe (100) having high detection accuracy includes a vibrator for vibrating the stylus in an axial direction, a detector (5) for detecting a vibration of the stylus by the vibrator, second vibrator for vibrating the stylus in a direction approximately parallel to an end surface of the workpiece, and a controller (31) for controlling movement of the support body (23) so that change in state quantity of a detection signal detected by the detector is constant.

Abstract: A fine feed mechanism (50) and a coarse feed mechanism (60) respectively for minutely and greatly displacing a stylus (12) is provided to a microscopic geometry measuring device (1), so that the respective mechanisms (50, 60) are combinedly actuated for easily controlling the movement of the stylus (12) in a wide range at a short time. Further, a movable balancing portion (53) moving in a direction opposite to a movable driving portion (52) is provided to the fine feed mechanism (50). Since a reaction force caused by the movement of the movable driving portion (52) is cancelled by another reaction force caused by the movement of the movable balancing portion (53) at a fixed portion (51), no mechanical interference is caused between the respective mechanisms (50, 60), thus accurately controlling the movement of the stylus (12).

Abstract: A stylus structure (40) integrally incorporating a stylus (2), a vibrator (4), a detector (6), a first secondary magnetic circuit (12) and a second primary magnetic circuit (21), and a stylus support (30) integrally incorporating a first primary magnetic circuit (11) and a second secondary magnetic circuit (22) are mutually fittable, thereby achieving signal transmission by the respective magnetic circuits using no electrical contact.

Abstract: A capacitive distance sensor adapted to measure a distance between an object and the sensor device, which is suitable for determining surface configuration of an object includes a objective electrode, moving device for the objective electrode and a detecting means of moving distance of the objective electrode. The moving device is controlled depending on the signal from the objective electrode to position it in a predetermined range of clearance. The distance between the object and the sensor device is calculated based on the signals from the detecting means and the objective electrode.

Abstract: Two all pass filers (11, 12) with 90° phase-shifted different center frequencies are employed to pass an alternating signal S with jitters in the period to generate signals, S1 and S2, 90° phase-shifted from each other. A pulse generator (22) generates a sampling pulse Sp by detecting a zero cross point of the phase-shifted signal S2. A full-wave rectifier (21) rectifies full waves of the phase-shifted signal S1 and provides a rectified output to a sampling circuit (23), which extracts a peak value of the amplitude at the timing of the sampling pulse Sp.

Abstract: A contact location detecting mechanism (1) of a touch signal probe (10) includes a rotary motion generator (30) for scanningly moving a stylus (102) on a plane (A), a phase value detector (50) for detecting a phase value (&thgr;) indicating a rotation position of the scanning rotary motion, and a contact location detector (70)for detecting a contact location of a contact portion (102A) based on a detection signal value (V) detected by the detector (103B) and the phase value (&thgr;). Since the contact location of the contact portion (102A) can be detected by the contact location detector (70), the touch signal probe (10) can be used for a profiling measurement and continuous measurement of a workpiece.

Abstract: A phase delay correction system for use in a shape measurement is capable of removing the distortion of a restored shape and the mechanical positional deviation caused by a phase delay occurring during signal processing, and enables a Fourier series processing procedure to be adopted as is. A detector performs a relative scan of an object to be measured at a constant speed. A signal processing unit converts a shape detection signal obtained by the scan to digital data, and processes the digital data.

Abstract: There is provided a length measuring machine which is not influenced by fluctuations of air or changes in temperature. At a structure, graduations are formed in a longitudinal direction, and further a built-in light wave interferometer is provided. The built-in light wave interferometer measures a length of the structure and supplies the data to a current controller. In order to reconcile a length of the structure with a nominal value, the current controller supplies current to an electrical resistor provided at the structure to cause thermal expansion of the structure, or the structure is cooled.

Abstract: Signals S.sub.j and S.sub.j-1 that are deviate from each other by a phase value of 2 .pi./M are generated by combining two sinusoidal detection signals. A reference signal .DELTA.S is generated which represents a difference between the signals S.sub.j and S.sub.j-1. An up-pulse or a down-pulse is generated every time the signal S.sub.j or S.sub.j-1 varies by .DELTA.S/n. An n-ary reversible ring counter outputs a first count value and a carry or borrow pulse by counting the up-pulse and the down-pulse, and the first count value is used to control the operation of generating the up-pulse or down-pulse. An M-ary reversible ring counter outputs a second count value by counting the carry pulse or the borrow pulse, and the second count value is used to control the operation of generating the signals S.sub.j and S.sub.j-1.

Abstract: A vector control apparatus for an induction motor that controls the speed of the induction motor by providing the motor with a speed command and a secondary magnetic flux command from outside. The vector control apparatus includes a vector control system operative in such a way as to maintain a vector relation equation between a torque current, an exciting current, a slip speed, a secondary magnetic flux command, on the one hand, and a torque T, on the other, of the induction motor; and memory system means for storing a predetermined relationship between the torque T, the detected speed value .omega..sub.r, of the motor, and the secondary magnetic flux command obtained from the vector control system. The torque T obtained from the vector control system is inputted to the memory system and the secondary magnetic flux is outputted and fed back therefrom to the vector control system. In the predetermined relationship, when he torque T is large, the secondary magnetic flux .phi..sub.

Abstract: Stator slots are skewed relative to rotor slots with a skew amount comprising an integer multiple of a stator electrical angle of 60.degree., thereby minimizing a torque ripple which is an integer multiple of six times of a primary frequency of electrical energy.

Abstract: A three-phase induction motor is subjected to countermeasure for the rotor and the stator in order to remove two harmonic components of the orders causing a torque ripple, among a plurality of harmonic components included in a magnetic flux generated in an air gap between a stator core and a rotor core. In the three-phase induction motor, conductor grooves of the rotor core are skewed by an electrical angle of 2.pi./n where n is the order of one of the harmonic components to be removed. In the stator, the number of slots (N) is selected so that an equation N=l.times.m.times.q is satisfied, where l=the number of poles, m=the number of phase, and q is a non integer number representing the number of slots per pole per phase, and the stator winding pitch is determined according to the order of another harmonic component to be removed.