Hitachi, Ltd.

Hitachi Media Electronics Co., Ltd.

Hitachi Metals, Ltd.

Norio Hosaka

Jun Yamada

Hitoshi Watanabe

Yuji Fujita

Akitsuna Yuhara

Makoto Katagishi

Takashi Shiba

Hideo Ohnuki

Kenji Hayashi

Takeshi Murakami

Kunikazu Ohnishi

Takeshi Nakao

Keisuke Fukamachi

Kiyoharu Kishimoto

Isao Akitake

Hiromi Kita

Toshiyuki Wada

Takemitsu Buma

Misao Nakajima

Optical beams emitted by optical sources are incident on a mirror surface of a scan mirror in a substantially vertical direction and reflected in a substantially vertical direction by the scan mirror. The mirror surface of the scan mirror is driven to repeatedly rotate two-dimensionally by a predetermined scan angle by a scan mirror drive circuit. A polarized beam splitter causes the optical beam emitted by the optical source to be incident on the scan mirror through a quarter wave plate, and outputs the optical beam that has been reflected by the scan mirror and passed through the quarter wave plate toward the screen. A scan angle expander is arranged on the output side of the polarized beam splitter, whereby the scan angle of the optical beam is increased by N times.

Scan type image display device

A multi-band transceiver has a function of sharing transmitted and received signals of multiple frequency bands by the same antenna. The multi-band transceiver mounts multiple filters that correspond to the multiple frequency bands and multiple amplifiers for amplifying the transmitted signals on the same substrate, and arranges the multiple filters in close vicinity to the amplifier in the order where the multiple filters are excellent in their temperature characteristic.

Multi-band transceiver and radio communication device using the transceiver

A surface acoustic wave device which comprises: a plurality of interdigital transducers formed on a surface acoustic wave substrate; and a plurality of thin film electrodes disposed between the interdigital transducers and an end surface of the surface acoustic wave substrate and electrically independently of the interdigital transducers, at least one of distances between adjacent ones of the thin film electrodes being set to be smaller than a distance between the thin film electrodes and the interdigital transducers, so that the electrical performance of the device as well as the insulation resistance does not deteriorate, and the interdigital transducers can be prevented from being electrostatically broken.

Surface acoustic wave device with closely spaced discharge electrodes

A high-frequency apparatus usable as a branching filter, branching filter module and/or a radio communication apparatus. The high-frequency apparatus includes a conductor substrate, a first dielectric layer provided on the conductor substrate, a strip conductor provided on the first dielectric layer, and a second dielectric layer provided on the strip conductor and having through holes provided therein. At least one elastic surface-wave element is provided over the second dielectric layer in a position above the strip conductor and is connected to the strip conductor by the through holes.

Branching filter, branching filter module and radio commnication

A plurality of interdigital transducers (IDTs) of a surface acoustic wave bandpass filter, each of which has a plurality of electrode fingers arranged in a direction perpendicular to a propagating direction of surface acoustic wave, are connected alternatively to an input terminal and an output terminal of said filter. The IDTs are different in number of electrode fingers and in average value of inter-finger distance from each other and distance between adjacent IDTs are different. At least one of the outermost IDTs has a minimum number of electrode fingers and a maximum average value of inter-finger distance, compared with those of other IDTs.

Saw filter and mobile telephone using same

A solid state electronic device having a thin film of an Al (aluminum) alloy Li (lithium) on the surface of a substrate for a surface acoustic wave (SAW). Interdigital electrodes, electric wiring patterns and bonding pads are formed by the thin film of the Li-added Al alloy. This thin film suppresses migration which occurs when a high density current is supplied to the device or a large amplitude SAW is generated. The thin film, which provides a small loss and relatively low hardness, provides a desired power handling capability and high yield of wire bonding. The this film assures high endurance to failure of the device and sufficient life of the device.

Solid state electronic device

A surface acoustic wave resonator has two solid-type interdigital transducers and two grating reflectors arranged on a piezoelectric substrate or on a surface acoustic wave substrate which contains a piezoelectric material and the reflectors are arranged outside these transducers. If the electrode pitch of the interdigital transducers is suitably different from the pitch of grating of the reflectors, ripples caused by the triple transit echo at frequencies other than the peak frequency are deviated so as to lie outside the stop band of the reflectors, so that spurious responses are suppressed. In this case, the number of electrode pairs Ni of the interdigital transducers should satisfy a relation, Ni.gtoreq..pi./.epsilon., wherein .epsilon. denotes a characteristic mechanical impedance mismatch contribution on the surface of the electrode and on the free surface in the interdigital transducers, so that a peak caused by the trapping of energy in the interdigital transducers is brought into agreement with a peak caused by the triple transit echo to decrease the losses and to increase the Q value.

Surface acoustic wave resonator

In an apparatus for descrambling a scrambled television signal, an elastic surface wave filter is used. This elastic surface wave filter has an interdigital electrode having an electrode pattern similar to at least portion of the waveforms of a luminance signal section of the scrambled television signal to be input. The elastic surface wave filter generates a response pulse only when the waveforms which are analogous to the electrode pattern of the interdigital electrode of the scrambled television signal were input, thereby descrambling the television signal using this response pulse.

Descrambling apparatus for a television signal

Disclosed is a surface acoustic wave transmission device comprising a piezoelectric substrate provided thereon with an input and output transducers for transmitting and receiving the surface acoustic wave, a package for accommodating the piezoelectric substrate, and an adhesion layer for fixing the bottom of the piezoelectric substrate to the ground plane of the package. The adhesion layer is made to have a thickness of .lambda..sub.R /2.6 or more wherein .lambda..sub.R : is the wave length of the surface acoustic wave at the main lobe of the operating frequency, so that unnecessary waves caused by bulk wave components are absorbed.

Growing community of inventors

Kamakura, Japan

Norio Hosaka