Abstract: The invention provides a stabilized frequency characteristic over a wide temperature range. A quartz resonating piece is provided such that an electrical axis of quartz corresponds to an X axis, a mechanical axis of the quartz corresponds to a Y axis, and an optical axis of the quartz corresponds to a Z axis. The quartz resonating piece includes a quartz plate having a side that is parallel to an X?axis set by clockwise rotation of the X axis around the Z axis by an angle equal to or greater than ?5.0° and less than ?1.0° or by an angle greater than +1.0° and equal to or less than 15.9°, and another side that is parallel to a Z? axis set by clockwise rotation of the Z axis around the X? axis by an angle in a range from 34.6° to 35.1° inclusive; or a quartz plate having a side that is parallel to the X? axis set by clockwise rotation of the X axis around the Z axis by an angle in a range from ?15.9° to ?5.

Abstract: An electronic apparatus comprises a display portion and a plurality of oscillators, one of which is a quartz crystal oscillator comprising: a quartz crystal oscillating circuit comprising; an amplification circuit and a feedback circuit. For example, the feedback circuit is constructed by a quartz crystal resonator comprising vibrational arms and a base portion, and having novel shape and electrode construction. Also, the quartz crystal resonator is housed in a package. In addition, from a relationship of an amplification rate of the amplification circuit and a feedback rate of the feedback circuit, an output signal of the quartz crystal oscillating circuit having an oscillation frequency of a fundamental mode of vibration for the quartz crystal resonator can be provided with a frequency of high stability.

Abstract: A piezoelectric quartz plate having reduced frequency deviation as a function of temperature, wherein the quartz plate is cut at an angle described by: 1 T f = ⁢ 3.9 + 6.

Abstract: A quartz crystal unit has a quartz crystal tuning fork resonator capable of vibrating in a flexural mode, a case for housing the quartz crystal tuning fork resonator, and a lid for covering an open end of the case. The quartz crystal tuning fork resonator has a tuning fork base, a pair of tuning fork tines connected to the tuning fork base, a series of grooves each formed on opposite main surfaces of each of the tuning fork tines, and a series of electrodes each disposed in a respective one of the grooves. When W and W2 represent a width of each tuning fork tine and a width of at least one of the grooves formed in the tuning fork tines, respectively, W2 is within a range of 0.03 mm to 0.12 mm, and a ratio (W2/W) is greater than 0.35 and less than 1.

Abstract: In a longitudinally coupled multi-mode piezoelectric bulk wave filter, a laminated piezoelectric body obtained by overlapping a plurality of excitation electrodes with piezoelectric layers therebetween and piezoelectric portions aligned with the laminated piezoelectric body are integrated. The thickness of each of the piezoelectric portions is greater than the thickness of the laminated piezoelectric body. The input electrode, the output electrode, and the ground electrode are connected to the respective excitation electrodes of the piezoelectric body. When an input signal is applied between the input electrode and the ground electrode, harmonics, with a plurality of different orders of vibrations, using the piezoelectric longitudinal effect are efficiently generated and are combined to produce the filter characteristic.

Abstract: A method of adjusting the temperature properties of piezoelectric devices and oscillation circuits which have a third-order function temperature property and the point of inflection of the third-order function temperature property outside the normal usage temperature range. The local maximum point or local minimum point temperature located in the normal temperature range is regarded as the peak temperature of the apparent second-order function temperature property, and the peak temperature is adjusted to the optimum value in the normal temperature range by rotating the temperature property around the point of inflection located outside the normal temperature range by adjusting the first-order coefficient.

Abstract: A motor-driven pump unit is provided having an electric motor comprising a stator, and a rotor, a pump, and a housing. The pump is concentrically enclosed by the rotor of the motor, and the rotor of the motor is U-shaped in an axial sectional view. The web of the U-shape is provided in the region of the common axis with internal gearing and the shaft of the pump has a pinion that mates with the internal gearing. The housing has a face wall on the web side and an opposite face on the connection side, which carries the connections for the medium to be conveyed. The housing can be arranged in the region of the face wall on the web side as a container for receiving the conveying medium or for receiving a cooling device or for receiving a filtering device.

Abstract: A piezoelectric quartz plate having reduced frequency deviation as a function of temperature, wherein the quartz plate is cut at an angle described by: T f = 3.9 + 6.

Abstract: A vibrating reed includes a base; and a vibration arm section formed so as to protrude from this base wherein a through groove is formed in the vibration arm section, and a rigidity reinforcing section is provided in the through groove, and thus the frequency is not decreased and the CI value is not increased.

Abstract: An immunoassay, e.g. ELISA, method and kit for determining (preferably quantitatively) an analyte adsorbed at a surface or present in a liquid sample, comprising binding the analyte to a solid phase, attaching a marker to the analyte, and detecting marker attached to the solid-phase. The invention proposes to use a combination of marker and detection (e.g. an enzyme-substrate combination) which is capable of producing a precipitate on a solid phase which carries the marker and to detect the binding of analyte to the solid phase by in-situ determining the change in surface mass of the solid phase due to the formation of the precipitate. Ellipsometry is an example of a technique suitable for determining the change of surface mass of the solid phase, which could be made of a silicon- or chromium-sputtered glass slide The invention shortens the assay time and/or improves the assay sensitivity, and allows to measure extremely low surface concentrations of analytes of interest.

Abstract: A vibration motor obtains a FAST signal when r.p.m. of the motor is faster than reference speed, whereby an output-driving circuit is controlled by the FAST signal to omit parts of the powering periods of respective phases. The motor thus controls the r.p.m. and increases torque ripple generated from the motor. As a result, vibration magnitude increases and insufficient vibration due to downsizing of the motor can be compensated by the control system.

Abstract: A surface mount quartz crystal resonator includes a quartz crystal-based plate including a central portion adapted to resonate at a desired frequency, and a border substantially surrounding a peripheral region of the central portion. The border includes a first region physically separated from the central portion, and a second region joined to the central portion. A base plate is provided which is secured to the plate so that the central portion of the plate is free to resonate relative to the base plate. A cover plate is provided and is secured to the plate so that the plate is located between the base plate and the cover plate. At least one, and preferably both, of the base plate and the cover plate are made of quartz.

Abstract: In an AT-cut quartz resonator having excitation electrodes formed on two principal surfaces of an AT-cut quartz substrate, the two electrodes are displaced a predetermined amount apart in a direction orthogonal to the X-axis direction so that a frequency deviation in a temperature range of from −10° C. to 50° C. is less than ±2.5 ppm. Further, in an AT-cut quartz resonator in which vertically opposed electrodes on both principal surfaces of a quartz substrate are slightly displaced apart in opposite directions along the Z′ axis of quartz crystal, a balancing load is formed on a piezoelectric substrate on the side opposite to the direction of displacement of the electrodes.

Abstract: The invention relates to a method of measuring pressure in which an evacuated capsule (1) containing a resonant element (5) is placed in the fluid whose pressure is to be measured, a vibration characteristic of the element is measured, and the pressure is deduced from said characteristic. A resonant element is used which, during measurement, is to be found in a stress state that is close to buckling. For this purpose, it is possible to use heater means for heating the element and servo-controlled so as to keep the frequency of vibration thereof constant. The resonant element can be made of silicon. The invention is particularly applicable to oil wells.

Abstract: The Lame mode quartz crystal resonator vibrating in overtone mode is formed of an X-plate quartz crystal obtained in a manner that a blank X-plate quartz crystal having a coordinate of x, y and z axes is rotated through 36.5° to 47° about its y-axis and further rotated through 65° to 85° about a new x′-axis corresponding to the x-axis produced by the rotation about the y-axis and the thus rotated blank X-plate quartz crystal is then cut out along planes parallel to x-y, y-z and z-x planes of the original coordinate system, respectively. The quartz crystal resonator includes a vibrating portion, a supporting frame and a mounting portion formed integrally. The vibrating portion is connected through two connecting portions to the supporting frame and the mounting portion, as a result of which the quartz crystal resonator has less series resistance R1 and exhibits minimum vibrational energy losses and minimum frequency change over a wide temperature range.

Abstract: A piezoelectric quartz plate having reduced frequency deviation as a function of temperature, wherein the quartz plate is cut at an angle described by: 1 T f = 3.9 + 6.

Abstract: The present invention concerns a low frequency oscillator device including a quartz resonator (1) and an electronic maintenance circuit for maintaining the vibrations of said quartz resonator. According to the present invention, the quartz resonator is arranged to vibrate according to a torsional mode and therefore has a single cutting angle defined by a rotation at a determined angle (&thgr;) about the crystallographic axis X of the quartz crystal. This resonator includes in particular at least one undesired fundamental flexural vibrating mode at a first frequency and a desired fundamental torsional vibrating mode at a second frequency higher than said first frequency. Moreover, the electronic maintenance circuit is an inverter circuit (2) whose transconductance value (gm) is determined such that said device cannot oscillate according to the undesired fundamental flexural vibrating mode but according to the desired fundamental torsional vibrating mode of said resonator.

Abstract: A method of manufacturing high reliability quartz crystal oscillators and a quartz crystal oscillator produced therefrom is disclosed. In the present invention, a quartz crystal oscillating plate is mounted to a ceramic base within the top cavity of the ceramic base by means of a plurality of metal bumps. The quartz crystal oscillator has a ceramic base formed by laminating a second ceramic layer along the periphery of the top surface of a first ceramic layer. The ceramic base has a top cavity, with a plurality of electrode terminals formed on the first ceramic layer at predetermined positions and electrically connected to external electrodes. A quartz crystal oscillating plate, having a plurality of electrode patterns, is mounted to the electrode terminals of the first ceramic base within the top cavity through a plurality of metal bumps such that a remaining part of the oscillating plate except for the terminals is spaced apart from the ceramic base by a gap.

Abstract: An object of the present invention is to provide a quartz resonator unit and a quartz oscillator having a small size and a light weight and having the capability of oscillating in the overtone mode, and also to provide a quartz element for use in the quartz resonator unit and quartz oscillator. Thus, a further object is to determine the optimum width-to-thickness ratio of the quartz element at which the quartz element having a width less than 1.5 mm and a length less than 4.7 mm does not show coupling with spurious vibrations over the entire range of operation temperature. From the experiments and evaluation performed repeatedly, it has been concluded that an AT-cut rectangular quartz element having the width-to-thickness ratio w/t in a range selected from the group consisting of 8.48 0.05, 12.18+/−0.05, 13.22+/−0.07, 14.78+/−0.07, and 15.57 0.07 is suitable as a small-sized quartz element that can oscillate at a high frequency and has excellent temperature characteristics.

Abstract: A surface acoustic wave resonator includes a piezoelectric substrate and an interdigital transducer disposed on the piezoelectric substrate and made of a metal or an alloy having a higher specific weight than that of the piezoelectric material of the piezoelectric substrate so as to generate shear horizontal waves. The interdigital transducer includes a plurality of electrode fingers. A ratio of the electrode finger width relative to the electrode finger width plus the space between adjacent electrode fingers is about 0.55 to about 0.85.

Abstract: The Lame mode quartz crystal resonator vibrating in overtone mode is formed of an X-plate quartz crystal obtained in a manner that a blank X-plate quartz crystal having a coordinate of x, y and z axes is rotated through 36.5° to 47° about its y-axis and further rotated through 65° to 85° about a new x′-axis corresponding to the x-axis produced by the rotation about the y-axis and the thus rotated blank X-plate quartz crystal is then cut out along planes parallel to x-y, y-z and z-x planes of the original coordinate system, respectively. The quartz crystal resonator includes a vibrating portion, a supporting frame and a mounting portion formed integrally. The vibrating portion is connected through two connecting portions to the supporting frame and the mounting portion, as a result of which the quartz crystal resonator has less series resistance R1 and exhibits minimum vibrational energy losses and minimum frequency change over a wide temperature range.

Abstract: An object of the present invention is to provide a quartz resonator unit and a quartz oscillator having a small size and a light weight and having the capability of oscillating in the overtone mode, and also to provide a quartz element for use in the quartz resonator unit and quartz oscillator. Thus, a further object is to determine the optimum width-to-thickness ratio of the quartz element at which the quartz element having a width less than 1.5 mm and a length less than 4.7 mm does not show coupling with spurious vibrations over the entire range of operation temperature. From the experiments and evaluation performed repeatedly, it has been concluded that an AT-cut rectangular quartz element having the width-to-thickness ratio w/t in a range selected from the group consisting of 8.48 0.05, 12.18 ±0.05, 13.22 ±0.07, 14.78 ±0.07, and 15.57 0.07 is suitable as a small-sized quartz element that can oscillate at a high frequency and has excellent temperature characteristics.

Abstract: Quartz crystal resonators 30 with a first angle of rotation having an X-axis 17 and Z′-axis 19 lying within a plane corresponding to an AT-cut and a second angle of rotation 34 within the plane of the AT-cut and lying within a range of about ±1° to about ±11.5° from the Z′-axis of the AT-cut. The resonators includes substantially opposing electrodes 36 disposed on major faces of the quartz crystal plate 32. The second angle of rotation 34 results in quartz crystal resonators 30 being produced with a more uniform distribution of temperature performances.

Abstract: A surface acoustic wave device includes a quartz substrate having an angle .theta. of Euler angles (0, .theta., 90.degree.) that satisfies 122.degree..ltoreq..theta..ltoreq.131.degree.. An interdigital transducer made of an electrode material including at least one of Ta and W is disposed on the quartz substrate.

Abstract: A pressure and temperature transducer includes an elongate housing formed from double rotation cut crystal quartz, an elongate plate-like resonator formed from double rotation cut crystal quartz capable of vibrating under an applied electric field located within the housing, the resonator being formed in unitary construction with the housing. The long edges of the resonator are connected to the interior walls of the housing, and short edges of the resonator are free and extend across the interior of the housing in a substantially continuous curve. Electrodes are located on opposite faces of the resonator for applying an electric field which causes the resonator to vibrate. End caps, formed from double rotation cut crystal quartz, are provided at each end of the housing. A borehole tool includes a tool body which can be positioned in a borehole, a probe for sampling fluid in the borehole; and a pressure and/or temperature transducer, connected to the probe for making measurements on the fluid.

Abstract: In an AT-cut quartz resonator having excitation electrodes formed on two principal surfaces of an AT-cut quartz substrate, the two electrodes are displaced a predetermined amount apart in a direction orthogonal to the X-axis direction so that a frequency deviation in a temperature range of from -10.degree. C. to 50.degree. C. is less than .+-.2.5 ppm. Further, in an AT-cut quartz resonator in which vertically opposed electrodes on both principal surfaces of a quartz substrate are slightly displaced apart in opposite directions along the Z' axis of quartz crystal, a balancing load is formed on a piezoelectric substrate on the side opposite to the direction of displacement of the electrodes.

Abstract: A dual-mode thickness-shear quartz pressure transducer includes a unitary piezoelectric crystal resonator and cylindrical housing structure wherein the resonator is located on a median radial plane of the housing and the exterior of the housing is provided with a pair of parallel flat surfaces which are located at an angle relative to the X" axis of the resonator. According to the presently preferred embodiment, the transducer is made from an SC-cut or a WAD-cut solid quartz crystal cylinder which is ultrasonically milled to form a plano-convex or bi-convex resonator disk in the medial radial plane of a hollow cylinder and the pair of exterior flats. The wall thickness of the cylinder is altered at the location of the flats such that stresses at the center of the resonator disk are anisotropic.

Abstract: A quartz single crystal substrate (12), includes a prescribed range of Euler angles for substrate and crystal orientation which improves signal processing for surface acoustic wave (SAW) devices (10). When a voltage is applied to an input inter digital transducer (IDT) (16) of the SAW device (10), a surface acoustic wave is generated in the quartz substrate (12). The surface acoustic wave propagates in a direction generally perpendicular to electrodes (20) of the IDT (16). The quartz crystal cut and wave propagation directions are defined to reduce the adverse effects of diffraction on SAW devices (10). As a result, frequency response distortions and insertion loss increases due to diffraction are reduced while maintaining good temperature stability and a low power flow angle.

Abstract: A crystal oscillator and method for manufacturing same including excitation electrode portions formed upon a crystal substrate and thus forming an excitation portion of the area defined between the electrode portions. Axis inversion portions possess an electrical axis (-X) opposite to the electrical axis (X) of the excitation portion, these axis inversion portions being formed within the crystal substrate at a position other than that of the excitation portion. A stable resonance frequency and filter frequency can be obtained even under conditions of ambient temperature fluctuation, by means of a relatively simple temperature compensation circuit, wherein handling is easy and no complicated adjustment is necessary, and low costs can be realized.

Abstract: A SAW device utilizing elastic surface waves, in which the Q value indicating resonance sharpness is high, and which presents excellent frequency temperature characteristics and short-term frequency stability. In a SAW device according to the present invention, an IDT and two reflectors are in parallel in the propagation direction of the phase of the elastic surface waves. The IDT and reflectors are disposed to cover the power flow direction, which is the propagation direction of energy of the elastic surface waves, whereby the energy of the elastic surface waves is efficiently confined. Moreover, it becomes possible to manufacture the SAW device utilizing a piezoelectric crystal in which angle .theta. and angle .psi. indicating excellent frequency temperature characteristics are 25 to 45 degrees and 40 to 47 degrees, respectively. It is also possible to manufacture the SAW device utilizing a piezoelectric crystal where angle .psi. is related to angle .theta. such that .theta.=2.775.times.(.psi.-32.5)+6.

Abstract: The invention is directed to resonators and more particularly to an MMIC-compatible resonator which can be fabricated on an MMIC chip using MMIC processing techniques. The MMIC-compatible resonator has a substrate approximately 100 microns thick made of semi-insulating GaAs and/or AlGaAs. The substrate flanks an air via on which is fabricated a thin film piezoelectric semi-insulating GaAs film, comprising the piezoelectrically active element. The piezoelectrically active element is flanked either laterally or from the top to bottom thereof by a pair of electrodes which serve to excite the thickness shear or thickness extensional mode of the thin film piezoelectrically active element. There are a number of III-V and II-VI binary compounds and ternary, and other piezoelectric semiconductor alloys, which can be used for the purposes of the invention. The thin film measures approximately 5 microns or less in thickness and is fabricated on the semi-insulating GaAs, on the ?110!, ?111! or ?100! axis thereof.

Abstract: A chemical sensor for measuring a change in the sensor mass relating to the interaction of a surface of the sensor with a solution comprises a crystal detector oscillator capable of providing a measurement signal based upon the resonant frequency of the crystal detector oscillator. The crystal detector oscillator has a first crystal side for directly contacting the solution, and a second crystal side isolated from contacting the solution. A first electrode is integral to the first crystal side, with the first electrode having an inner and outer perimeter defining an outer portion of the first crystal side which is exterior to the outer perimeter of the first electrode and an inner portion of the first crystal side which is interior to the inner perimeter of the first electrode. A second electrode is integral to the second crystal side.

Abstract: A multi-mode piezoelectric filter includes a piezoelectric substrate made of a LiTaO.sub.3 single crystal, a plurality of spaced electrodes which are formed adjacently on a front major surface of the substrate, and a counter electrode which is formed on a rear major surface of the substrate in opposition to the spaced electrodes. The spaced electrodes and the counter electrode coact with the intervening portion of the substrate to form two or more energy trapped type multi-mode filter elements vibrating in the thickness shear mode such that the filter elements are coupled to form a cascade connection. Damping material such as silicone gel is applied at least on the filter elements.

Abstract: A quartz oscillator temperature sensor which measures temperature based on the change in resonance or oscillation frequency of a quartz oscillator with the change in temperature the oscillator can be constructed by cutting a piece of quartz from a wafer with a thickness of about 80 to 150 .mu.m by rotating the plane of the crystal defined by the electrical and mechanical axes 15.degree. to 25.degree. about the electrical axis and then forming the wafer into a quartz tuning fork. The tuning fork is housed in a case sealed with a stem and coupled to electrical leads with heat resistent solder formed with more than about 90 wt % Pb and less than 10% Sn. The area within the case should be at a substantially high vacuum.

Abstract: The invention is a crystal oscillator having a vibrating plate comprising a vibrating part surrounded by a rim part spaced from the vibrating part except for a narrow connecting part that connects the vibrating part to the rim part in a cantilever fashion. The thickness of the vibrating part and the connecting part are less than the thickness of the rim part. The vibrating part is sandwiched between a pair of casings. Each of the casings has a recess facing the vibrating part, which prevent the vibrating part from contacting the casings. Each surface facing a recess has an electrode positioned thereon and an electrode lead extending from the surface electrode to the connecting part. Each casing has a through-hole positioned to face an electrical lead. A cup-shaped metal lead is placed in each through-hole with the bottom of the cup contacting the electrical lead facing the through-hole. Current to the surface electrodes is supplied through the metal leads.

Abstract: A piezoelectric device includes a piezoelectric plate provided with at least one electrode at almost a central portion of each face; a first plate made of an ionic material having a recessed portion to cover the at least one electrode at one face to face the piezoelectric plate; and a second plate made of an ionic material having a recessed portion to cover the at least one electrode at one face to face the piezoelectric plate. Each of the at least one electrode is packaged by direct bonding the piezoelectric plate with the first plate and the second plate so as to be sandwiched therebetween. A package includes a body member made of an ionic material provided with a recessed portion or an opening, having a flat face around the recessed portion or the opening; and a covering member made of an ionic material having a flat face to cover the body member.

Abstract: A method of rotating a non-temperature compensated Bechmann curve of a quartz strip. The method includes the steps of determining (102) whether a crystallographic orientation of an AT cut quartz strip is within a desired specification; selecting (104) a predetermined nominal electrode coverage having a nominal electrode width for an in-specification AT cut quartz strip; and tuning (106) an out of specification crystallographic orientation, by: adjusting (108) the electrode width with respect to the nominal electrode width, to bring the out-of-specification crystallographic orientation of an out-of-specification AT cut crystal quartz to within a desired specification having an in-specification Bechmann curve with an inflection point; and rotating (110) an out-of-specification Bechmann curve about the inflection point to substantially approach the desired in-specification Bechmann curve.

Abstract: The present invention relates to a low profile monolithic crystal strip filter and filter package. The filter includes an AT-cut rectangular strip of quartz crystal. The filter further includes input, output and ground electrodes which are formed in a symmetrical pattern on the strip. Each electrode is connected to its respective mounting or ground contact by a flag. The electrodes, contacts and flags have a predetermined size and shape, and are arranged in a predetermined configuration on the crystal strip to minimize spurious responses and insertion losses. The crystal strip is mounted to an HC-45 or HC-49 base to minimize production costs. The output signal of the filter has a center frequency of about 4 to 500 MHz, a 3 dB bandwidth of about 3 to 250 kHz, an ultimate of better than 60 dB, standard insertion losses for the number of poles in the filter and commercially acceptable spurious responses.

Abstract: To improve temperature compensation of a piezoelectric element measuring mechanical variables, such as pressure, force, and acceleration, with two or more piezoelectric crystal elements, at least one of the crystal elements differ from the other crystal element(s) either physically or chemically, the positive temperature coefficient of a piezo-coefficient of at least one piezoelectric crystal element compensating the negative temperature coefficient of the other crystal element(s), so that the overall piezoelectric sensitivity of the measuring element will remain essentially constant within a given temperature interval.

Abstract: The present invention provides for methods of increasing the frequency vs. temperature ("f vs. T") stability of Oven Controlled Crystal Oscillators to levels which are superior to atomic frequency standards and 100 to 10,000 times higher than that currently available from the best crystal oscillators. This method encompasses the steps of making an SC-cut quartz resonator with upper and lower turnover temperatures at or near the resonator's inflection temperature, inserting the resonator into a high-stability oscillator circuit, placing the circuit into a high-stability, high thermal gain oven and adjusting the oven temperature to a set-point at or near one of the resonator's turnover temperatures.

Abstract: A method and device for selectively reducing the frequency-temperature-shift of piezoelectric crystals. The piezoelectric device (100) includes a substrate (102), a piezoelectric element (106) and a temperature dependent interface structure (120) for beneficially stressing the piezoelectric element at a predetermined temperature range. The substrate (102), piezoelectric element (106) and temperature-dependent interface structure (120) define a piezoelectric package having a predetermined non-compensated third order Bechmann curve having a low temperature end and a high temperature end, with an inflection point therebetween, whereby the frequency-temperature shift is reducable on the third order Bechmann curve.

Abstract: A method of adjusting a frequency-to-temperature coefficient of an NS-GT cut quartz resonator comprises providing a coupling resonator having a first order temperature coefficient .alpha..sub.+. A normalized frequency .delta. of the coupled vibrational modes is then calculated according to the relationship .alpha..sub.+ =m.delta.+n, where m and n are constants. The normalized frequency .delta. is then adjusted according to the relationship .alpha..sub.+ =m.delta.+n to set the first order temperature coefficient to substantially zero.

Abstract: An oscillator has a pair of upper and lower casing members in the form of plates, and a vibration plate pinched between the upper and lower casing members. A tongue-like vibrating portion is formed by forming a slit in the vibration plate inside an outer peripheral portion of the vibration plate pinched between the upper and lower casing members. Electrodes are formed on obverse and reverse surfaces of the vibrating portion.

Abstract: A piezoelectric crystal element for surface acoustic wave applications with a quartz substrate with at least one substantially planar quartz surface, the planar quartz surface having an epitaxially grown layer of a quartz-isomorphous crystal with the total molecular formula ABO.sub.4, A standing for Al or Ga, and B for P or As, and the quartz surface and the epitaxial layer having approximately the same crystallographic orientation.

Abstract: A crystal resonator including at least three, typically four linear electe segments, formed on one of the major faces of piezoelectric resonator blank and providing at least two gaps which are selectively excited by RF voltages of predetermined magnitude and phase for generating a resultant lateral-field oriented at an arbitrary angle .PSI. with respect to the coordinate axes of the crystal plate for varying the lateral-field piezoelectric coupling k which is a parameter indicative of the degree to which an electrical energy is converted to mechanical energy in the resonator. By adjusting the magnitude and phases of the excitation voltages, applied to the electrode segments, the lateral-field direction becomes steerable so as to alter the electrical characteristics of the resonator including the lateral-field excitation antiresonance frequency.

Abstract: An AT-cut crystal oscillating reed formed by etching an AT-cut crystal wafer is provided. The wafer has a rotational parallel cut obtained by rotating a parallel cut by an angular degree of .theta..degree. relative to the X-axis of the wafer. The etching cross-section of the AT-cut crystal oscillating reed has a surface at an angle about 90.degree. from the front or back surface of the AT-cut crystal oscillating reed. This AT-cut crystal oscillating reed exhibits uniform characteristics and excellent reliability. Also provided is an AT-cut crystal oscillating reed with a low CI value. Finally, a method of etching an AT-cut crystal oscillating reed from an AT-cut crystal wafer is provided. A corrosion resisting film with gaps coats the wafer and is used in the etching process. In a preferred embodiment, the thickness of the wafer is designated t, the width of the gaps in the corrosion resisting films is designated l, and l.gtoreq.t/tan .theta..

Abstract: A torsional quartz crystal resonator has a specific cut type resulting in improved frequency temperature behavior. The cut type is defined by rotating a Z plate quartz crystal around an x-axis at an angle .phi. in the range of 0.degree. through 30.degree. and by further rotating the plate around a z'-axis at another angle .theta. in the range of -20.degree. through -10.degree. or +10.degree. through +20.degree.. The resonator has a thickness z.sub.0 and a width x.sub.0 determined such that a thickness-to-width ratio Rzx=z.sub.0 /x.sub.0 is set within the range of 0.6 through 1.1 to make the first order temperature coefficient substantially zero in combination with the optimum angles .phi. and .theta.. Excitation electrodes are disposed on major faces of the resonator normal to the z' axis, and a connecting electrode is disposed on a side face of the resonator to reduce the series resistance R.sub.1.

Abstract: A quartz oscillator temperature sensor which measures temperature based on the change in resonance or oscillation frequency of a quartz oscillator with the change in temperature of the oscillator can be constructed by cutting a piece of quartz from a wafer with a thickness of about 80 to 150 .mu.m by rotating the plane of the crystal defined by the electrical and mechanical axes 15 to 25.degree. about the electrical axis and then forming the wafer into a quartz tuning fork. The tuning fork is housed in a case sealed with a stem and coupled to electrical leads with heat resistent solder formed with more than about 90 wt % Pb and less than 10% Sn. The area within the case should be at a substantially high vacuum.

Abstract: A width-extensional mode quartz crystal resonator formed by etching from a quartz crystal plate which is cut along a plane defined in the O-xyz coordinate system of the quartz crystal lattice by rotating the original Z plane around the x axis by a rotation angle in the range of 23.degree.-28.degree.. The quartz crystal resonator has a thickness-to-width ratio R.sub.zx in the range of 0.45-0.65. A pair of exciting electrodes are disposed on the resonator along opposed side faces perpendicular to the widthwise direction. The width-extensional mode quartz crystal resonator may be etched from a quartz crystal plate to provide a small sized resonator. A width-extensional mode vibrational portion is supported at its lengthwise sides by a pair of first bridge portions extending from a first frame portion. A pair of second bridge portions extend from a second frame portion and support the first frame at central portions of its lengthwise sides.

Abstract: An acoustic wave device employing surfaces skimming bulk waves comprises a piezo electric substrate having a flat surface which carries an input transducer and an output transducer for respectively lanuching and receiving acoustic waves into and from the bulk of the substrate. The substrate may be of quartz, lithium tantalate, or lithium niobate and has the flat surface orientated so that a surface skimming bulk wave is launched without generation of surface acoustic waves.