Matsushita Electric Industrial Co., Ltd.

Takahiro Nishikura

Osamu Kawasaki

Katsu Takeda

Masanori Sumihara

Katsumi Imada

Takashi Nojima

Tetsuro Ohtsuchi

Tetsuro Otsuchi

Shigeo Suzuki

Hidenobu Shintaku

Masanori Sumhara

An acceleration sensor includes: a piezoelectric vibrator including a piezoelectric element having a first principal surface and a second principal surface opposed each other, a first and a second electrode formed on the first and the second principal surface, and conductive protrusions made of a metal material or a ceramic material and formed by a thermal spraying process; and a holding body for holding the piezoelectric vibrator via the conductive protrusions.

Acceleration sensor and method for producing the same

A pyroelectric IR sensor equipped with a chopper for opening and closing a shielding plate so that infrared rays emitted from an object are allowed to be incident onto a pyroelectric sensor unit and intercepted therefrom, and having a structure capable of providing a large shielding width for the shielding plate without enlarging the chopper. Piezoelectric members are formed on a thin elastic sheet composed of a planar sheet having a tip to which a shielding plate is attached, except for a partial region which functions to magnify oscillations for enlarging displacement of the shielding plate.

Pyroelectric IR sensor

An ultrasonic motor has a vibrating body 3 and a moving body 11 supported by a supporting component 7. A rounded lower end of the supporting component is supported in a tapered dent of a supporting base 10, and therefore when a side pressure is applied, it inclines to the supporting base so as to keep the contact between the vibrating body and moving body stable. As a result, a stable motor rotation is always obtained regardless of side pressure. A lead wire 8 is held between a metal elastic element 1 and supporting component, and is pressed against the elastic element. Hence, the lead wire, through contact with the elastic element, is electrically coupled to the common electrode on the upper surface of a piezoelectric element without soldering and without use of conductive resin.

Ultrasonic motor

The present invention relates to a method for driving an ultrasonic motor of the type which includes a vibrator for causing a flexural vibration wave in response to a pair of AC driving voltage signals, and a rotor in contact with the vibrator and moved by the flexural vibration wave. The rotational speed of the ultrasonic motor is controlled by using a feedback signal and a data table, the feedback signal indicating the current rotational speed of the ultrasonic motor, and the data table storing values of the feedback signal as a standard function of the rotational 21 speed. The method includes the step of sampling the feedback signal and detecting the rotational speed in a plurality of rotation states of the ultrasonic motor. The method obtains an approximate function representing the relationship between the sampled feedback signal and the detected rotational speed of the ultrasonic motor, and calculates correction coefficients for adjusting the approximate function to the standard function. The method then controls the rotational speed of the ultrasonic motor by using the feedback signal. In the controlling step, the method corrects the feedback signal obtained from the ultrasonic motor by using the correction coefficient, whereby a value of the approximate function is transformed into a corresponding value of the standard function.

Method for driving an ultrasonic motor

A method for controlling a moving velocity of an ultrasonic motor comprising a vibration body for causing ultrasonic vibration in response to two AC driving voltage signals having a common frequency, a common amplitude and phases different from each other; and a moving body in contact with the vibration body and moved by the ultrasonic vibration. The method includes step A of detecting a velocity of the moving body; step B comparing the velocity detected in step A with a predetermined velocity; and step C for adjusting the frequency of the two AC driving voltage signals and the amplitude of or the phase difference between the two AC driving voltage signals, based on the comparison result to allow the velocity of the moving body to be closer to the predetermined velocity.

Method and an apparatus for controlling a moving velocity of an

A position where the projection member is disposed is optimized by the product of a vibration displacement distribution of a vibration member composed of an elastic member for exciting the primary elastic progressive waves or more in the radial direction and the tertiary elastic progressive waves or more in the peripheral direction, and a generation force distribution of a vibration member to be caused in accordance with the pressure force so that the motor output is made larger. The construction is optional in accordance with the necessary characteristics, and the characteristics are superior by the shape of the supporting means of the vibrating member and the vibration member, thus providing an ultrasonic motor of higher stability.

An ultrasonic motor which achieves uniform contact between the vibrating body and the moving body and features high output transfer efficiency and high reliability, and by which the manufacturing process for the moving body thereof can be simplified and the moving body made lighter. By comprising the moving body of a carbon fiber reinforced resin composite material reinforced by at least carbon fiber, and constructing the moving body with a both-side supported or single-side supported beam construction, elasticity according to the pressure of the ultrasonic motor can be imparted in the direction of pressure of the moving body. Thus, the undulations in the contact surface of the vibrating body and the moving body can be absorbed and stable, uniform contact can be assured, and long-term maintenance of a stable friction condition can be achieved.

Ultrasonic motor with vibrating body and moving body driven thereby

An ultrasonic motor comprising vibrating body, piezoelectric body for exciting an elastic travelling wave in the vibrating body and moving body driven by the elastic travelling wave provides plural vibration amplitude detection electrodes for detecting an amplitude of vibration of the vibrating body these output signals from which are utilized to identify the magnitude of vibration amplitude of the vibrating body and the ultrasonic motor is controlled using the magnitude of vibration amplitude as a control index.

Ultrasonic motor and ultrasonic motor control method

A bimorph element is formed by bonding first and second piezoelectric bodies together with an elastic shim interposed between. The bimorph element is firmly held by a base frame which has a recess and a groove at the bottom of the recess. The elastic shim 103 has an extending portion which is firmly inserted in the groove and its end portion is inserted in the recess of the base frame. A space between the recess and the end portion of the bimorph element is filled by an elastic support member.

Piezoelectric head actuator

In an ultrasonic motor having a rotor (6,12) and a vibrating stator (43,49) wherein travelling wave is excited to drive the rotor, the vibrating stator comprises a piezoelectric member (25,26,29,60) and alternately-disposed first segment electrodes and second segment electrodes, the first segment electrodes being connected with each other to form a first intermittent ring or linear electrode train and the second segment electrodes being connected with each other to form a second intermittent ring or linear electrode train, each of the segment electrodes having a length of a quarter of wavelength of the travelling wave in the direction of the travelling wave and being to be polarized in an opposite direction to adjacent electrodes within the same segment electrode.

An ultrasonic motor achieves uniform contact between a vibrating body and a moving body and features high output transfer efficiency and high reliability. The manufacturing process for the moving body can be simplified and the moving body made lighter by making the moving body of a carbon fiber reinforced resin composite material reinforced by at least carbon fiber, and constructing the moving body with a both-side supported or single-side supported beam construction. Elasticity according to the pressure of the ultrasonic motor can be imparted in the direction of pressure of the moving body. Thus, the undulations in the contact surface of the vibrating body and the moving body can be absorbed, stable, uniform contact can be assured, and long-term maintenance of a stable friction condition can be achieved.

Ultrasonic motor with a vibrating body and a moving body driven thereby

In a linear-type actuator where an elastic wave is excited upon the vibrator composed of a rod shaped elastic member and a piezo member so as to drive the moving member bought into pressure contact upon the vibrator, the present invention provides a linear-type actuator where the improvement of the driving efficiency and the simplification of the driving circuit can be achieved by the new driving principle.

Linear-type actuator

An ultrasonic motor has a circular vibrator and a mover which is pressed into contact with the circular vibrator. A circular elastic member which constitutes the circular vibrator has a uniform thickness along a circumferential direction thereof, and has a plurality of recesses on a face of the circular elastic member opposing the mover. According to the above structure, uniform elastic travelling waves are generated in the circular elastic member of the vibrator, and a uniform contact is attained between the vibrator and the mover, and yet the development of cracks at bottoms of the recesses is prevented. A ring-like recess is provided on another elastic member which constitutes the mover.

Growing community of inventors

Ikoma, Japan

Takahiro Nishikura