Abstract: A detection circuit for a vibratory gyro includes a first circuit which detects a detection signal output from the vibratory gyro and produces an output signal indicative of an angular velocity applied to the vibratory gyro, and a second circuit which is operatively coupled to the first circuit and reduces a leakage component included in the detection signal.

Abstract: A tuning-fork vibratory gyro has first and second arms and a base integrally connected to the first and second arms. The gyro includes drive electrodes used to generate tuning-fork vibrations due to a piezoelectric transversal effect, and detection electrodes provided on the first and second arms and used to output a detection voltage due to an angular velocity.

Abstract: A tuning-fork vibration gyro includes a tuning-fork vibrator having two arms and a base portion, and a supporting portion located in a center of a rotational motion of the base portion caused by a vibration resulting from a Coriolis force. The supporting portion protrudes from two surfaces of the base portion opposite each other in a direction in which the vibration resulting from the Coriolis force occurs.

Abstract: A tuning-fork type piezoelectric vibratory gyroscope includes a tuning fork having two arms and a base portion integrally formed with the two arms and having electrodes, and a supporting base supporting the base portion of the tuning fork. An adhesive layer joins the base portion and the supporting base together so that the tuning fork and the supporting plate are elastically integrated within a temperature range in which the gyroscope is used.

Abstract: A method of producing a SAW (Surface Acoustic Wave) device, including the steps of implanting ions in an entire surface of a piezoelectric member of the SAW device, so that an ion implantation layer is formed therein; performing a heat treatment of the piezoelectric member, so that a heat-treated ion implantation layer is formed in the entire surface of the piezoelectric member; and providing an electrode of a comb type resonator on the heat-treated ion implantation layer.

Abstract: The multimode surface acoustic wave filter includes two surface acoustic wave resonators closely arranged on a piezoelectric substrate in a direction perpendicular to the propagation direction of surface acoustic waves and acoustically coupled by a coupling section, each of the surface acoustic wave resonators including an interdigital transducer and two reflectors disposed closely on both sides of the interdigital transducer in a direction parallel to the propagation direction of the surface acoustic waves, the interdigital transducer having an excitation section for exciting the surface acoustic waves and a signal terminal section for inputting an electric signal, each of the reflectors having a grating section and a terminal section, wherein the velocity of surface acoustic waves propagating through the coupling section is a little larger than the velocity of the surface acoustic waves propagating through the excitation section of the interdigital transducer.

Abstract: A surface acoustic wave filter includes a piezoelectric substrate, input and output IDTs, and first and second direction changing electrodes, wherein at least one of the input and output IDTs includes a weighted interdigital transducer, the input and output IDTS being arranged in a direction perpendicular to a propagation direction of a surface acoustic wave (SAW) oscillated by the input IDT. The first direction changing electrode changes the propagation direction of the SAW, which has propagated in a left directed from the input IDT, into a direction towards the output IDT. The second direction changing electrode changes the propagation direction of the SAW, which has propagated in a right direction from the input IDT, into a direction towards the output IDTs and the first and second direction changing electrodes is set for obtaining at the output IDT the SAW having desired frequency characteristics.

Abstract: In a tuning fork type vibration element provided in a tuning fork type vibration gyro, the sum of inertial moments of a base to an inertial moment of two arms is 1.0 or larger. The inertial moment of the two arms is obtained by multiplying the square of a rotation radius, which is a distance from a center axis of torsional vibration as a center position between the two arms to a center of gravity of the two arms with a mass of the two arms, and the inertial moment of the base is obtained by multiplying the square of the rotation radius from the center axis of the same torsional vibration.

Abstract: A surface acoustic wave device includes a piezoelectric substrate and plural IDTs for sending and receiving SAW mounted on the substrate. At least one of the IDTs includes a positive electrode including plural positive split electrodes (PSEs) and a negative electrode including plural negative split electrodes (NSEs). The PSEs and NSEs are arranged alternately. Each of the PSEs andNSEs has apair of electrode fingers. Two electrode fingers of each of the split electrodes are different in width in a direction in which a SAW is excited. An angle .alpha. determined by a direction transverse to the electrode fingers from one of the two electrode fingers having a smaller reflection factor toward the other one having a larger reflection factor and a direction in which the SAW excited by the IDT including the split electrodes travels to one of the IDTs for receiving the SAW is equal to or larger than 0.degree. and smaller than 90.degree., i.e., 0.ltoreq..alpha.<90.

Abstract: A synchronous generator which is driven by an engine whose rotation variation is large and which can easily incorporate an output voltage stabilization circuit. In this synchronous generator, magnetism shorting paths for a magnetic field produced by the armature coil is formed without changing the armature specifications. Magnetic fluxes produced by currents flowing in the armature coils can easily pass through the magnetism shorting paths, thereby increasing the equivalent inductance value and improving the frequency characteristic of the inductance. This in turn improves the voltage step-up chopper characteristic during generation to stabilize the generated voltage of the synchronous generator driven by, for example, an automobile engine that widely varies in revolution speed.

Abstract: A surface acoustic wave device includes a plurality of surface acoustic wave filter chips having external connection terminals and a package accommodating the plural surface acoustic wave filter chips. The package is provided with a plurality of terminals for connection with the surface acoustic wave filter chips, and one of the external connection terminals of a first one of the surface acoustic wave filter chips is connected with one of the terminals of the package via a second one of the surface acoustic wave filter chips.

Abstract: The shape of drive electrodes and/or the shape of detection electrodes of a tuning fork type vibration gyro are made asymmetrical between the inside and outside of the arm, and between the surface and reverse face of the arm, to reduce the abnormal vibration and leaking output. The drive electrodes to be provided on the inside parts of the surface and reverse face of the first arm are formed smaller than the drive electrodes to be provided on the outside parts of the surface and reverse face thereof. The length of the detection electrode to be provided on the outside lateral face of the second arm is formed short. The drive electrodes to be provided on the surface and reverse face of the first arm are extended to the base side from the boundary position between the first arm and the base, and the detection electrodes to be provided on the surface and reverse face of the second arm are extended to the base side from the boundary position between the second arm and the base.

Abstract: A surface acoustic wave filter of multi-stage connection type including a plurality of surface acoustic wave filters formed on a piezoelectric substrate and a connection section for electrically connecting the surface acoustic wave filters in a cascade connection. Each of the surface acoustic wave filters includes interdigital transducers with two signal terminals for electric input and output, each interdigital transducer including an excitation section for exciting a surface acoustic wave and two terminal sections disposed on opposite sides of the excitation section, the two terminal sections serving as input or output terminal for electric signal and ground terminal. One of the signal terminal sections is connected to the connection section, and an electrode area of said one of the signal terminal sections is adjusted so that a parasitic capacitance formed between said one of the signal terminal sections and a grounding point of the surface acoustic wave filter is less than or equal to 0.01 pF.

Abstract: In a surface acoustic wave filter constituted with a ladder of resonators having a resonance frequency or an anti-resonance frequency, an input current flowing into a resonator in a parallel arm at the first stage from the input is so large as to deteriorate its lifetime caused from a heat generation by the resistance of the thin film wiring. As a measure to this problem, bonding wires (30, 31) connected onto points on connection electrodes (130, 131) for connecting an end of each of plural comb teeth electrodes 111 forming the resonators R.sub.s1 & R.sub.p1, or on a lead conductor (130-1) extended longitudinally from the connection electrode, are allotted at both sides of a center line (C1) of the plural comb teeth electrode group. Furthermore, a bonding wire may be connected substantially onto the center line C1 as well. It is preferable for the bonding wires to be located substantially symmetric with respect to the center line C1.

Abstract: This invention relates to a control apparatus for permanent magnet type generators, having a voltage control unit for controlling a voltage of a permanent magnet type generator driven by an automobile engine, and a power conversion unit for converting the DC source power of an automobile into commercial AC power during the stoppage of the engine. The voltage control unit is capable of reducing the number of large current switching elements, being formed to small dimensions and weight and having economically advantageous effects, and comprises an engine-driven permanent magnet type generator, a voltage step-up and rectifying circuit for increasing the voltage of output power generated by the generator, and a conversion circuit adapted to convert an output from the voltage step-up and rectifying circuit into three-phase AC power by a pulse-width modulation control system, and having a voltage step-down function.

Abstract: A surface acoustic wave device includes an electrode formed by a first film and a second film on a substrate, the first film including an Al film or a film formed by adding at least one other element to Al, and the second film including a metal whose coefficient of diffusion into Al is greater than a self diffusion coefficient of Al. The present invention contributes to improvement of the high-power durability of the electrodes.

Abstract: A cathode ray tube display device including unnecessary radiating magnetic field reducer which improves the ability to reduce an unnecessary radiating magnetic field, especially, generated by a vertical deflection coil. A pair of coil is disposed in opposing relationship on the opposite sides of the ferrite core along an X-axis or in the horizontal direction of the deflection yoke so as to be in contact with an open side end of the ferrite core. Each coil has a shape curved with a predetermined radius of curvature conforming to the shape of the outer peripheral surface of the ferrite core. The ferrite core acts as a magnetic material for the coils which reduces the unnecessary radiating magnetic fields to increase the coil inductances to thereby produce a large extremely low frequency magnetic field (ELMF) reducing effect.

Abstract: An oscillation circuit of phase-shift type includes a surface acoustic wave filter in a feedback circuit, the surface acoustic wave filter having first and second one-port surface acoustic wave resonators of different resonance frequencies connected in a ladder configuration. The oscillation circuit has a high C/N ratio with a large bandwidth of variable frequency and can be fabricated in a small size with low costs.

Abstract: A duplexer package comprises two surface acoustic wave filter chips having different band center frequencies and a phase matching circuit for matching the phases of the two SAW filter chips, the filter chips and the phase matching circuit being accommodated in one unit, wherein the phase matching circuit is formed in a layer providing a cavity for the filter chips, the layer defining the cavity being located above a face for mounting the surface acoustic wave filter chips. According to the present invention, the height of the duplexer package can be lowered.