Murata Manufacturing Co., Ltd.

Chikashi Kondo

Seigo Hayashi

Junshi Ota

Haruo Morii

Junichi Nishie

A laminated piezoelectric element that includes a piezoelectric element layer and a matching layer. The piezoelectric element layer is configured to have a plurality of piezoelectric layers and a plurality of electrode layers laminated together. The matching layer is laminated on the piezoelectric element layer, and is different in acoustic impedance from the piezoelectric element layer. When Vp represents the acoustic velocity in the piezoelectric element layer, Vm represents the acoustic velocity in the matching layer, Tp represents the thickness dimension of the piezoelectric element layer, and Tm represents the thickness dimension of the matching layer, Vp/Vm=Tp/Tm holds. Further, when W represents the dimension of the laminated piezoelectric element in the width direction, Tp+Tm&#x3e;W holds.

Laminated piezoelectric element and multi-feed detection sensor

A medium fatigue detection apparatus and a medium fatigue detection method detect fatigue of a sheet-like medium. The apparatus includes an ultrasonic sending device for oscillating ultrasonic waves as burst waves, an ultrasonic receiving device, and a sensed intensity detector. The ultrasonic sending device and ultrasonic receiving device are arranged to oppose each other and allow a sheet-like medium to pass between them. The ultrasonic waves sent from the ultrasonic sending device are incident on a principal surface of the sheet-like medium at a predetermined incident angle &#x3b8;. Fatigue of the medium is detected by measuring a variation in sensed intensity of the ultrasonic waves having passed through the sheet-like medium.

Medium fatigue detection apparatus and medium fatigue detection method

A surface acoustic wave filter includes a glass substrate, an interdigital transducer provided on the glass substrate, a piezoelectric film arranged on the glass substrate so as to cover the interdigital transducer; a terminal electrode provided on the glass substrate and electrically connected to the interdigital transducer; and a coating film having an area smaller than that of the terminal electrode. The coating film is arranged on the terminal electrode such that a portion of a top surface of the terminal electrode is exposed throughout the periphery thereof.

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Kanazawa, Japan

Chikashi Kondo