Hitachi, Ltd.

Michiyori Miura

Masamichi Yamada

Jun Yamada

Katashi Hazama

Katsuo Konishi

Hitoshi Yanagihara

Yoshihiko Noro

A thin-film-type magnetic head device for magnetically recording and/or reproducing signals in and from a magnetic recording medium has a lower magnetic layer, an insulating layer, a thin-film-type coil and an upper magnetic layer which are formed sequentially on a substrate such that a magnetic circuit is formed by the upper and lower magnetic layers. The upper and lower magnetic layers partially abut each other to provide a magnetic coupling therebetween. At least one slit formed in the region where the upper and lower magnetic layers abut each other, so as to suppress generation of eddy currents in the magnetic layers in the region.

Thin-film-type magnetic head device

To eliminate disturbance signals caused by the reflection from the unitary stem areas of comb-like electrodes of an interdigital transducer in an elastic surface wave device, the edges of the unitary stem areas perpendicular to the surface wave propagating direction includes at least one pair of partial edges, the positions of the partial edges in each of the at least one pair of partial edges differ by (2n+1).multidot..lambda./4 from each other in the surface wave propagating direction, and the lengths of the partial edges in the each pair are equal to each other, where n represents zero or a positive integer and .lambda. represents the wavelength of the elastic surface.

Elastic surface wave device

An elastic surface wave device for use as an electronic element such as a delay line or a filter in home-use electronic apparatus such as color television receivers and radio receivers and in industrial electronic apparatus such as electrical communication units. In the elastic surface wave device which comprises a substrate of piezo-electric material, an electro-mechanical input transducer converting an electrical input signal into an elastic surface wave, and a mechano-electrical output transducer disposed opposite to the input transducer through an elastic surface wave propagation path for converting the propagating elastic surface wave into the electrical signal again, at least two kinds of ultrasonic wave absorbing materials having different absorption coefficients for absorbing an unnecessary elastic surface wave portion are disposed in closely adjacent relation on the substrate surface in the region along the advancing direction of the unnecessary elastic surface wave portion between the opposite ends of the substrate, except the active region including the transducers and the propagation path, thereby improving the effect of unnecessary wave absorption.

Growing community of inventors

Yokohama, Japan

Michiyori Miura