Matsushita Electric Industrial Co., Ltd.

Takashi Nojima

Osamu Kawasaki

Takahiro Nishikura

Masanori Sumihara

Katsu Takeda

Katsumi Imada

Shigeo Suzuki

Tetsuro Ohtsuchi

Tetsuro Otsuchi

Hideo Kurokawa

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

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

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 a heat-plasma-jet, an arc is initially generated between opposed endless ends of a pair of electrodes and is moved along the opposed endless ends of the electrodes by generating magnetic fields having the same polarity at the opposed ends of the electrodes. Thereafter, a plasma generating gas is supplied into a region in which the arc is generated.

Growing community of inventors

Katano, Japan

Takashi Nojima