Abstract: An electroded wafer for use in electro-optic devices comprising a ceramic wafer having piezoelectric properties and having faces substantially larger than the thickness of the wafer. On the wafer are a plurality of parallel slots cut in at least one face of said wafer to form an interdigital matrix wherein adjacent slots are cut through the periphery of the wafer at opposite ends. Further included is a metallic electrode plated on the interior of the slots and the periphery of the wafer by electroless plating of at least one metal in contact with a palladium catalyzing compound such that the catalyzing compound is present only on the portions of the wafer to be plated.

Abstract: A piezoelectric actuator for use in controlling the path length in a ring laser is made up of a plurality of piezoelectric discs which have a different polarity in their central area than at their circumference so as to result in exerting a pushpull effect on the mirror which they control permitting fewer discs to be used, a lighter structure and a structure which is stiffer and has a more rectilinear motion without deleterious rotation.

Abstract: A disc of piezoelectric ceramic with a plurality of parallel slots cut into a top surface. Another plurality of slots is cut into the bottom surface of the disc with the parallel slots on the top being perpendicular to the parallel slots on the bottom. For one application a shallow keyway slot is cut into the top and/or bottom surface, traversing the already cut slots, to serve as a receptacle for an electrode ribbon.

Abstract: A cylindrical transducer for providing an omnidirectional beam pattern in one plane and a line radiation pattern in planes normal to the omnidirectional pattern. The cylindrical transducer active element is a radially poled piezoceramic having a surface into which a square thread is spirally cut so that only a pair of electrical leads are needed to excite the whole assembly. In one embodiment the thread is cut entirely through the thickness of the cylinder and in another embodiment it is cut partially through.

Abstract: Quartz resonator with electrodes that do not adhere to the crystal. Quartz resonator having improved medium-term and long-term stabilities and permitting easier placing on frequency. The resonator comprises, inside a tight housing 1, a condenser formed by two disks 3, 4 made of a dielectric material and separated by a removable ring 2 which determines the spacing between the disks 3 and 4. Electrodes are formed by metallization on the faces of the disks 3 and 4 located opposite a quartz crystal 1 enclosed in said condenser. The spacings between the crystal 1 and the disks 3 and 4 are considerably less than 1 millimeter. Application, for example, in the fields of telecommunications and radars.

Abstract: A wide band proportional transducer array including a plurality of active oustic elements. The elements are concentrically mounted to form a conical array. A proportionality constant k is selected to be such that a nearly constant composite array impedence is achieved. The proportionality constant relates to the ratio of the resonant frequencies of adjacent elements and inversely as the ratio to their physical sizes. Another embodiment employs a pair of conical arrays which results in a toroidal beam.

Abstract: A thickness shear resonator used as an overtone quartz crystal for a quartz stabilized oscillator which has an operating frequency in the MHz range that has an excitation electrode on each of its plane parallel surfaces running in the x, z' plane and where the thickness of the vibrator in the y' direction is determined by the distance of these surfaces from one another wherein the vibrator presents a dimensional ratio between its dimensions measured in the z' direction and its thickness which is determined by a fundamental quartz crystal frequency having a value of 1/3 of the operating frequency, thus, resulting in an oscillator which is not sensitive to influences from associated oscillating components.

Abstract: A piezoelectric flexural vibrator comprises a circular or polygonal disc of piezoelectric crystal such as quartz, lithium tantalate or lithium niobate which is formed by chemical etching and is supported around its periphery with electrodes on opposite faces comprising a pair of electrodes each of which is divided into two portions of which one is on one face of the disc and the other is on the opposite face of the disc. By reason of its small size -- 25 to 150 microns thick and less than 10mm across -- and its good frequency-temperature characteristics, the vibrator is suitable for use in wristwatches.

Abstract: A flow meter particularly for receiving respiratory flows for pulmonary function diagnoses has a perforated piezo-ceramic flow resistance element and transducer in a flow tube for providing a highly-sensitive flow measurement with little resistance to the flow. Electric contact plates abut opposite planar faces of the piezo-ceramic material plate and are spaced apart at the periphery of the piezo-ceramic plate by an insulating disk. Frame members carry the piezo-ceramic plate and electric contact plates and are spaced and protected within a housing of the flow meter by soft, floating seal members. Contact lugs connected to the electric contact plates conduct signals from the meter which are a function of the bending of the piezo-ceramic material plate under the differential flow pressures on an upstream and a downstream side of the piezo-ceramic plate.

Abstract: Combination Doppler and B-scan ultrasonic imaging apparatus is disclosed which includes visual display means for the simultaneous visual display of received ultrasonic Doppler and B-scan information. The apparatus includes first and second focused transducers associated with the Doppler and B-scan systems, which transducers are individually mounted for movement along parallel linear paths. The transducers each comprise a generally semi-cylindrical shaped body of piezoelectric material having opposite end faces upon which electrodes are disposed for connection to Doppler and B-scan transmitter and/or receiver units. The flat side walls of the piezoelectric bodies are positioned closely adjacent a mid-plane extending between the transducers, and means are provided for focusing the transducers at substantially the same depth for operation along a common focal region at, or adjacent, the mid-plane. One such focusing means includes acoustic lenses carried by the piezoelectric bodies.

Abstract: An electromechanical micropositioner for making minute angular and linear translational displacements of an element attached to same. The micropositioner employs electrical control potentiometers, a power source, and a signal source that provides for the type of displacement desired.

Abstract: An improved AT-cut crystal oscillator for electronic watches. The AT-cut crystal oscillator is of substantially disc-shape. Furthermore, the AT-cut crystal oscillator is shaped in cross-section such that the periphery of the disc-shaped crystal oscillator is abruptly tapered. In the preferred embodiment, the cross-section is trapezoidal.

Abstract: In a bulk piezoelectric crystal an arbitrary wavefront of an acoustic wave is reconstructed from an array of wavelets generated subjacent a set of interdigital electrodes on a surface of the crystal.

Abstract: An ultrasonic wave generator includes an ultrasonic oscillator, an ultrasonic wave transducer connected to the oscillator, a mechanical vibration amplifying member, and an ultrasonic vibratory member. An increased thickness portion, which projects from a portion of the circumferential surface of the ultrasonic vibratory member and from a side wall portion of the mechanical vibration amplifying member at a connecting portion of the ultrasonic vibratory member and the mechanical vibration amplifying member, is integrally formed upon the ultrasonic vibratory member and the mechanical vibration amplifying member whereby the cross-sectional area of the connecting portion between the ultrasonic vibratory member and mechanical vibration amplifying member is gradually changed.

Abstract: An electrical pickup unit for sensing vibrations particularly in the audible range as produced by musical instruments such as stringed instruments like guitars and violins or wind instruments like trumpets and clarinets. The unit includes a flex or bender type piezoelectric element secured to a diaphragm resiliently mounted and adapted to sense the vibratory energy surfaces such as at the root of the strings of stringed instruments or at the bell of wind instruments.

Abstract: A bimorph bender is comprised of a pair of piezoelectric circular discs having diametrically opposed surface portions. Signal carrying electrodes are formed contiguous with each surface portion. A center vane is sandwiched between the discs maintaining them in a fixed spaced relation. The bender dishes in response to the electrical signals appearing at the electrodes.Mechanical coupling to the bender is provided by a washer which is affixed in the central portion of the bender. The washer is made of a high specific stiffness material for maintaining a high electro-mechanical coupling factor. The resulting structure provides a highly reliable and efficient power transducer.

Abstract: A piezoelectric disc having opposed major surfaces with electrodes affixed thereto bonded in generally parallel overlying relationship to a piezoelectrically inactive acoustic radiation member by means of an elastomeric interlayer, which elastomeric material is characterized by having a shear modulus which varies directly with the frequency of stresses applied to said elastomeric material.

Abstract: A crystal controlled square wave oscillator requiring a minimum number of components, exhibiting high frequency stability, and operating at substantially a 50% duty cycle. A quartz crystal dual monolithic resonator is provided having a pair of signal electrodes and a reference electrode. The resonator is capable of oscillating in symmetric and anti-symmetric modes, points of minimum attenuation, the symmetric mode exhibiting a 180.degree. phase shift, and the anti-symmetric mode exhibiting a phase shift of 0.degree.. An integrated circuit logic gate is connected between the signal electrodes, the logic gate being of the type having low input and output impedances so as not to degrade the Q of the resonator. The logic gate provides a phase shift of 180.degree. or 0.degree. causing the resonator to oscillate in its symmetric or anti-symmetric modes, respectively, the gate switching between its two logic levels to produce a square wave output at the frequency of the excited mode.

Abstract: A damped piezoelectric ceramic resonator. The resonator is a thin flat plate of piezoelectric ceramic material which has parallel major planar surfaces and is polarized in one direction in such a way that said direction is at an angle of from 0.degree. to 60.degree. with respect to said major surfaces, the thickness dimension of said plate being such as to impart thereto a resonance of vibrations in a thickness-shear mode at a particularly selected frequency higher than one megacycle. Operating electrodes are applied to said major planar surfaces. Vibration damping means is attached tightly to the contour of the edge of said flat plate so as to suppress unwanted resonance vibrations in said flat plate during operating. The vibration damping means is a ring of a rubber material having a hardness from 20 to 70 on the Shore A Scale and is under a tension of 20-500 gm/cm.

Abstract: The transducer of this invention utilizes an annular lithium niobate crystal operated in the compression mode with the sensitive axis of the crystal arranged at an angle of about -51.4.degree. to the Z, or optical, axis of the crystal in the first and third quadrants of the Y-Z plane of the crystal. This accelerometer has high efficiency and operates effectively over a wide range of temperatures, including high temperatures above 1000.degree. F.