Hitachi, Ltd.

Hitachi Medical Corporation

Shigeru Jyomura

Yukio Ito

Hiroshi Takeuchi

Sakichi Ashida

Kazuyuki Nagatsuma

Etsuji Yamamoto

Gyozo Toda

Katsuki Miyauchi

Iwao Matsuyama

Tsune Miyashita

Kunio Yamashita

Mitsuru Ishii

Hirosi Takeuchi

An apparatus for and a method of non-destructively determining properties of a SAW substrate, in which first and second interdigital transducers are formed in a spaced relationship on a single common piezoelectric substrate, a blocking member is formed between said transducers on the substrate for preventing an acoustic wave signal from being transferred between said transducers via the common substrate, spacers are provided for supporting a to-be-determined SAW substrate above the common substrate with a spacing left between the SAW substrate and the fingers of transducers, the SAW substrate to be placed on the spacers is positioned with respect to the transducers so that co-directional mode coupling will, in operation, effectively take place between the SAW substrate and the transducers, adherence between the SAW substrate and the spacers is secured to enhance the co-directional mode coupling, an electric signal is applied to the first transducer for transferring, due to the co-directional mode coupling, an acoustic signal to the SAW substrate along the surface of which the acoustic signal will propagate and will be transferred, due to the co-directional mode coupling, to the second transducer, and the output of the second transducer is measured.

Apparatus for and method of determining properties of saw substrates

A piezoelectric substance, which comprises a ternary solid solution having a composition represented by the general formula:

Piezoelectric substances

An ultrasonic probe includes a resonator made of a piezoelectric ceramic material which is obtained by subjecting a ceramic composition containing 44.7 to 46.3 mol % of PbO, 50.9 to 51.7 mol % of TiO.sub.2, 1.8 to 2.7 mol % of Sm.sub.2 O.sub.3 and 0.5 to 1.0 mol % of MnO.sub.2 to poling treatment in such a manner that the ceramic composition is applied with an electric field of 60 to 80 kV/cm at a temperature of 130.degree. to 160.degree. C.

Ultrasonic probe

Piezoelectric ceramics containing PbO and TiO.sub.2 as its principal constituents, and further containing 0.5 to 3.7 mol-% of Nd.sub.2 O.sub.3 and 0.2 to 1.5 mol-% of MnO.sub.2. Since the piezoelectric ceramics is low in the dielectric constant and is especially small in the temperature coefficient of the delay of surface acoustic waves, it is suitable for a surface acoustic wave device. Piezoelectric ceramics in which 0.3 to 3.3 mol-% of In.sub.2 O.sub.3 is further added to the above-mentioned composition has a still smaller temperature coefficient of the delay of surface acoustic waves, and it is also possible to make this coefficient zero.

Piezoelectric ceramics

A pulse generator comprising an induction element, and a nonlinear condenser whose dielectric material portion is made of ferroelectric ceramics represented by a general formula of (Pb.sub.1-x-y, Ba.sub.x, Sr.sub.y)(Ti.sub.z, Zr.sub.1-z)O.sub.3.

Pulse generator

Growing community of inventors

Tokyo, Japan

Shigeru Jyomura