摘要:
A surface acoustic wave device is provided. The surface acoustic wave device includes a piezoelectric substrate and an IDT which is disposed on the piezoelectric substrate and made of Al or an alloy containing Al as a main component and using an SH wave as an excitation wave, wherein the piezoelectric substrate is a rotated Y-cut quartz plate having a cut angle θ set to a range of −64.0°
摘要:
An information processing apparatus for processing encrypted data input as a byte stream with dynamically changing decryption keys includes the following elements. An encrypted data receiving section receives encrypted data input as a byte stream, identifies a range of data that is decrypted using an identical key as a unit of decryption, extracts information necessary for decryption from the byte stream, and outputs encrypted data sets in which the extracted information is added to segments of the encrypted data. An encrypted data decrypting section sequentially decrypts the encrypted data by queuing the encrypted data sets while distributing the encrypted data sets to generate plaintext data. A plaintext processing section processes the generated plaintext data.
摘要:
A vehicular suspension control apparatus includes a selector valve for changing at least one of spring rigidity or damper rigidity of a suspension which is installed between a wheel and a body of a vehicle and extensibly and retractably supports the vehicle body on the wheel, a forward road surface sensor attached to the vehicle body and adapted to detect an irregularity of a road surface located in front of the vehicle body at a predetermined distance from the mounting position of the sensor when the vehicle body is in a predetermined attitude, a vehicle speed sensor for detecting a vehicle speed, and a controller for calculating a point of time when the wheel reaches the irregularity of the road surface, in accordance with the vehicle speed detected by the vehicle speed sensor, when the irregularity of the road surface is detected by the forward road surface sensor, and delivering a command signal for lowering at least one of the spring rigidity and the damper rigidity of the suspension to the selector valve by not later than the calculated time point.
摘要:
An active suspension apparatus is provided for a vehicle which includes an actuator being extensible and retractable and provided between a vehicle body and a wheel so that the force of the vehicle body to support the wheel is adjustable, a sprung G sensor or a vehicle height sensor for detecting a vibration input to the vehicle body, and a control valve and a controller for controlling the supporting force of the actuator in accordance with the vibration input detected by the sprung G sensor or the vehicle height sensor, and thereby restraining the stroke of the actuator. The suspension apparatus further comprises a forward road surface sensor for detecting the size of irregularities of a road surface in front of the vehicle, and the control valve and the controller are adapted to execute normal control such that the equivalent spring constant of the actuator is adjusted to a first spring constant when a surface irregularity of a size larger than a predetermined size is detected by the forward road surface sensor, and to execute inverse spring control such that the equivalent spring constant of the actuator is adjusted to a second spring constant lower than the first spring constant, and thereby lengthening the stroke of the wheel, when no surface irregularity of a size larger than the predetermined size is detected by the forward road surface sensor. As a result, the ride is greatly improved when the vehicle runs on a smooth road.
摘要:
In an ultrathin piezoelectric resonator including an ultrathin vibratory portion and thick frame-like marginal portion formed integrally therewith for supporting it around, an electrode and an electrode lead pattern extending therefrom are provided on one surface of the vibratory portion and an electrode is provided on the other surface of the vibratory portion in an area except at least an area corresponding to the electrode lead pattern, thereby preventing that a capacitor is formed between the electrode and the electrode pattern deposited on the opposite surfaces of the vibratory portion and increases the parallel capacitance of the resonator. The electrode lead pattern is formed narrow to reduce an ohmic loss and suppress a spurious resonance. A through hole is made in the frame-like marginal portion and extends therethrough in its thickwise direction. By electrically connecting via the through hole an electrode lead portion on one surface of the frame-like marginal portion and a terminal pad on the other surface thereof, it is possible to ensure good conduction between a conductive film on the bottom of a resonator package and the electrode on the said other surface of the vibratory portion on the side where a cavity is provided.
摘要:
In a piezoelectric resonator having an ultrathin vibratory portion formed by a cavity made in a piezoelectric block and a thick frame-like rib formed integrally with said vibratory portion and surrounding it, an excess adhesive receiving groove or the like is cut in one marginal portion of the frame-like rib between an adhesive coated region. The resonator is fixedly housed in a package by use of an adhesive coated on one marginal portion of the frame-like rib along the z-axis direction, or by means of elastic pawls without using the adhesive. In this case, one marginal portion of the frame-like rib on the opposite side from a pad deposited on one side of the piezoelectric resonator is bonded to the bottom of the package. With such a structure, it is possible to prevent the adhesive from flowing into the cavity to cause variations in the resonance frequency of the piezoelectric resonator, to reduce the scatter of the temperature-frequency characteristic of a piezoelectric device using the resonator housed in a package during mass production, and to increase the bond strength of wire bonding for electrical connection of the piezoelectric resonator incorporated in the package.
摘要:
A high frequency narrow-band pass multi-mode filter in constructed in such manner that SAW of SSBW resonators are closely disposed to each other on a single piezoelectric substrate to generate different vibration modes of different resonance frequencies, conditions that the resonators are acoustically coupled to each other to cause these vibration modes, are experimentally found, and the above conditions are satisfied by the filter.In order to reduce the ohmic loss of a very narrow common bus bar, the number of strip pairs of electrode in both interdigital transducers (hereinafter referred to as IDT) is minimized and instead reflectors are provided on the both sides TDTs to compensate for the reduction of its Q value. A part of the bus bar for the IDT electrodes is formed integral with some or all of gratings of the reflectors, whereby the connecting positions of the grating electrodes with respect to lead terminals can be positioned with a high freedom.