US3833825A - Wide-band electroacoustic transducer - Google Patents

Wide-band electroacoustic transducer Download PDF

Info

Publication number
US3833825A
US3833825A US34993773A US3833825A US 3833825 A US3833825 A US 3833825A US 34993773 A US34993773 A US 34993773A US 3833825 A US3833825 A US 3833825A
Authority
US
United States
Prior art keywords
body
transducer
poles
grooves
window
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
Inventor
D Haan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Alliant Techsystems Inc
Original Assignee
Honeywell Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Honeywell Inc filed Critical Honeywell Inc
Priority to US34993773 priority Critical patent/US3833825A/en
Application granted granted Critical
Publication of US3833825A publication Critical patent/US3833825A/en
Anticipated expiration legal-status Critical
Assigned to ALLIANT TECHSYSTEMS INC. reassignment ALLIANT TECHSYSTEMS INC. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HONEYWELL INC. A CORP. OF DELAWARE
Application status is Expired - Lifetime legal-status Critical

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B06GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
    • B06BMETHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
    • B06B1/00Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
    • B06B1/02Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
    • B06B1/06Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezo-electric effect or with electrostriction
    • B06B1/0644Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezo-electric effect or with electrostriction using a single piezo-electric element
    • GPHYSICS
    • G10MUSICAL INSTRUMENTS; ACOUSTICS
    • G10KSOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18Methods or devices for transmitting, conducting, or directing sound
    • G10K11/26Sound-focusing or directing, e.g. scanning
    • G10K11/32Sound-focusing or directing, e.g. scanning characterised by the shape of the source

Abstract

A thickness-mode electroacoustic transducer wherein an active body of non-uniform thickness is employed to provide uniform wide-band frequency response. The body may be wedge-shaped, having non-parallel planar major surfaces. At least one of the major surfaces is subdivided into a two-dimensional array of poles by means of grooves formed in the surface for the purpose of providing improved frequency and directional response.

Description

Sept. 3, 1974 Emited States mm [1 1 Haan XXXXX 5000 9HHH9 VOOOW H444 333 a u u c a I. r m mtlt neave cfiksk umoao C30 0 KPCMC 60 3 56777 99999 lllll 20272 1 Apr. 11, 1973 Primary ExaminerMark O. Budd [57] ABSTRACT A thickness-mode electroacoustic transducer wherein 21 Appl. No.: 349,937

an active body of non-uniform thickness is employed to provide uniform wide-band frequency response. The body may be wedge-shaped, having non-parallel planar major surfaces. At least one of the major surfaces is subdivided into a two-dimensional array of poles by means of grooves formed in the surface for wmj d s a UIF 1]] 218 555 rlll [56] References Cited UNITED STATES PATENTS the purpose of providing improved frequency and directional response.

Guerbilsky..............,....... 310/9 6 X Bokovoy...............v.....i........BIO/9.6

310/9 6 x 9 Claims, 3 Dr g Fig res 9 9 344 999 Ill 5 0 SOUND PRESSURE LEVEL 0) and does not require critical design of the transducer housing and/or electrical signal processing circuitry.

Additional objects of the present invention may be ascertained from a study of the drawings, specification, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the applicants uniquely configured active body for an electroacoustic transducer;

FIG. 2 is a sectional view of a wide-band sonar transducer including the active body shown in FIG. 1 with electrodes attached and mounted in a water tight housing; and

FIG. 3 is a pair of operational curves for illustrating relative bandwidths of the applicants transducer and a typical prior art wide-band transducer.

DESCRIPTION OF THE PREFERRED EMBODIMENT The transducing element shown in FIG. 1 comprises a body 11 formed from a thick sheet or plate of piezoelectric ceramic material. Suitable ceramic materials for this purpose include barium titanate and lead zirconate titanate. Body 11 has opposing nonparallel major surfaces 12 and 13. Surfaces 12 and 13 may be planar, thus providing for a body of wedge-shaped or tapered configuration. Sets of grooves 14 and 15 are formed in surface 12 to subdivide the surface into a two-dimensional array of poles 16. Each pole has a face 17 which lies in surface 12.

Sets of grooves 14 and 15 may be located along two sets of equally-spaced parallel lines, each set intersecting the other so as to form a regular pattern. As shown in FIG. 1, sets of grooves 14 and 15 are at right angles to one another. However, such a geometric relationship is not required for proper operation. The grooves may, for example, be located along unequally spaced lines. Further, grooves 14 may be oriented at an acute angle relative to grooves 15.

Theoretically, the spacing between adjacent grooves should be such that the maximum cross-sectional dimension of each pole is less than one wave length at the resonant frequency of that pole. Thus, the spacings between adjacent grooves may vary depending on the location of the grooves between the thick and thin edges of the piezoelectric body. However, from a production viewpoint, it has been found more practical to evenly space the grooves. Also, it has been found more effective to space the grooves so that maximum crosssectional dimensions of the poles are approximately one-half wave length at the highest operating frequency of the transducer.

Operational transducers have been constructed with spacing between adjacent grooves as small as one millimeter. The width of the grooves should be as small as possible to minimize the volume of ceramic material removed, and thereby maximize the power-handling capabilities of the transducing element. Minimum groove width is determined by the width of the cutting or forming tool, and may be in the order of a few thousandths of an inch.

The ceramic material from which body 11 is formed is polarized to operate in a thickness mode. Stated otherwise, an alternating electrical potential applied between surfaces 12 and 13 causes alternating changes in the thickness of body 11. Conversely, mechanical forces which cause alternating thickness changes result in generation of an alternating potential between surfaces 12 and 13.

One of the functions of grooves 14 and 15 is to minimize mechanical coupling between poles 16. Since any solid material connecting individual poles results in mechanical intercoupling, optimum operation is achieved if the grooves are as deep as possible. However, it is also necessary to maintain the structural integrity of body 11. For operational purposes, the depth of grooves should be at least percent of the body thickness. It has been found that forming the grooves to a depth of percent of the minimum body thickness leaves sufficient material beneath the grooves to prevent fracture during normal handling and operation. In the preferred embodiment shown in FIG. 1, the grooves extend to a uniform distance from surface 13, forming rows of poles of increasing (or decreasing) height.

From an operational viewpoint, lateral dimensions L, and L of body 11 are dictated by directional response or beam width requirements. Practical considerations presently limit dimensions L and L to a maximum of approximately 2 inches. However, the effect of a larger bady can be achieved by mounting individual bodies side by side and energizing them in parallel.

Beam width in a given plane is inversely proportional to the lateral dimension in that plane. Hence, beam width in a plane parallel with indicated dimension L, is inversely proportional to the magnitude of L The beam width in a plane parallel with indicated dimension L tends to be inversely proportional to the magnitude of L However, the asymmetry of body 11 in planes parallel with dimension L complicates the relationship between the magnitude of dimension L and beam width in planes parallel therewith. It has been found that for a thickness taper of 4 degrees, the effective radiating aperture is approximately 0.82 L The multiplying factor is believed to vary inversely with taper angle.

FIG. 2 shows a complete sonar transducer in which previously described body 11 is provided with electrodes 20 and 21 and mounted within a fluid tight housing 22. Surfaces l2 and 13 may be prepared in a conventional manner for attachment of electrodes 20 and 21. For example, a silver paste may be screened on the surfaces and tired, or the surfaces may be sprayed with a silver paint. Electrodes 20 and 21 are then secured to the prepared surfaces.

In order to achieve optimum operation, there must be uniform mechanical loading of the poles and minimum mechanical coupling between poles. It is also important that the electrode on the pole faces have a smooth and flat exterior surface for mounting against a flat acoustic window or radiation into a fluid medium. These requirements impose certain restrictions on electrode 20. One improved electrode configuration which has been found quite satisfactory comprises metal foil bonded to the pole faces by means of an adhesive. Foil tape having a pressure sensitive adhesive backing has been found satisfactory for this purpose.

Electrode 21 may be of the same type as electrode 20. Alternatively, if body 11 is of the illustrated configuration wherein grooves are formed in only one major surface, electrode 21 may be any one of various suitable prior art types of electrodes, or a simple soldered wire connection.

WIDE-BAND ELECTROACOUSTIC TRANSDUCER BACKGROUND OF THE INVENTION The invention herein described was made in the course of or under a contract, or subcontract thereunder, with the Department of the Navy.

This invention pertains generally to acoustic transducers, and more specifically to thickness-mode electroacoustic transducers having relatively uniform frequency and directional response over a wide band of frequencies.

For purposes of the following discussion, it is pointed out that certain terms used as a matter of convenience are most commonly associated with projection of acoustic energy. However, the discussion applies to both acoustic projectors and hydrophones.

Commercial and military interest in transmitting and receiving underwater acoustic signals has increased rapidly in recent years. One of the most widely used items of equipment for this purpose is the electroacoustic transducer. Most prior art electroacoustic transducers are inherently relatively narrow frequency band devices. A basic reason for this is that each transducer, including its transducing element and associated electrodes, acoustic decouplers and housing, comprises a dynamic structural system having a fundamental resonant frequency and other dynamic characteristics which limit its frequency response.

One common type of electroacoustic transducer, known as a thickness-mode transducer, employs a transducing element of which the lateral dimensions are larger than the thickness. The transducing element is polarized so that its thickness changes in response to a changing electrical potential applied across the element. Conversely, any mechanical force which changes the thickness of the element results in generation of a changing electrical potential thereacross.

Thickness-mode transducers as described above are entirely adequate for many underwater electroacoustic transducer applications. Further, such transducers of conventional narrow frequency band design have the added advantage that problems in achieving satisfactory frequency and directional response are generally minimized. Nevertheless, they frequently exhibit somewhat anomalous frequency and directional response characteristics. Such characteristics become increasingly pronounced and troublesome in transducers designed for operation over wider bands of frequencies.

A variety of techniques have been devised in attempts to minimize side lobes and other unwanted forms of radiation which to some degree, degrade the response patterns of all transducers. One such technique involves forming grooves in a face of the transducing element. The grooves have the effect of interrupting the propagation of unwanted (typically radial or lateral) modes of vibration in the element, thereby minimizing undesired patterns of radiation. Transducers employing this technique are described in greater detail in U.S. Pat. Nos. 2,956,184 and 3,470,394 issued respectively to Hyman Pollack on Oct. 11, 1960 and Rufus Cook et al. on Sept. 30, 1969.

Another prior art technique (also described in U.S. Pat. No. 2,956,184) involves contouring the transducing element so that an electrical signal applied between opposing faces thereof subjects the center of the element to a higher electrical gradient than that near its outer edge. According to the patent, the outer edge of the element is believed to be principally responsible for radiating side lobes. Hence, by differentially polarizing the transducing element so that its outer edge is driven less vigorously than its central portion, directional response is improved.

Yet other techniques which have been attempted for minimizing unwanted transducer radiation include mechanical tuning of the transducing element-housing assembly, the use of electrical signal shaping circuitry, and the use of acoustical baffles for defining a window through which radiation is permitted.

Whereas conventional narrow-band transducers have been generally satisfactory for many past transducer applications, an increasing number of requirements are now developing for transducers capable of efficient operation over an extended band of frequencies. Wideband operation greatly increases the severity of problems involved in achieving acceptable directional response, and necessitates the use of special features to minimize such problems. The transducer disclosed in previously identified U.S. Pat. No. 3,470,394 employs a transducing element of which opposite faces are cross serrated or diced to permit operation over a somewhat wider band of frequencies than prior art transducers. Although transducers of this design provide somewhat improved wide-band performance, they have not been found capable of acceptable operation over bands of frequencies which are sufficiently wide to meet various present transducer requirements.

The applicant has discovered an electroacoustic transducer element of unique design which provides uniform response over a substantially increased band of frequencies. The design includes features for minimizing radiated side lobes and other unwanted response characteristics. Thus, the broad band capabilities may be effectively used to maximum advantage.

SUMMARY OF THE INVENTION The invention herein described is a thickness-mode electroacoustic transducer comprising an active body having non-parallel major surfaces for transmitting or receiving acoustic energy. At least one of the major surfaces is subdivided by means of grooves to form a two-dimensional array of poles. The major surfaces are provided with electrode means for carrying electrical signals to or from the poles.

In a preferred embodiment, the non-parallel major surfaces are planar so that the body is of a generally wedge-shaped configuration. The grooves may be located along two intersecting sets of parallel lines so as to form a regular pattern, and may extend to a uniform distance from the surface opposite the grooved surface, thereby forming poles of varying heights. The electrode means may comprise conductive foil bonded to the major surfaces by means of an adhesive.

A principle object of this invention is to provide an improved electroacoustic transducer which is capable of efficient operation over a wide frequency band.

A further object is to provide a wide-band electroacoustic transducer capable of producing a satisfactory directional response pattern at all frequencies within its operating frequency band.

Yet a further object is to provide a uniquely configured transducing element which is suitable for wideband operation; is simple and economical to produce;

Electrodes and 21 are attached to insulated conductors 23 and 24 respectively. Conductors 23 and 24 pass through a fluid tight feedthrough fitting 25 in housing 22 and into a cable 26 which carries electrical signals between electrodes 20, 21 and conventional electrical signal processing circuitry not shown in FIG. 2.

Housing 22 is provided with a window 27 which is suitable for the transmission of acoustic energy. The transducer embodiment shown in FIG. 2 is air filled. In such an embodiment, structural acoustic decouplers are not required. In addition, the assembly comprising body 11 and electrodes 20, 21 may be secured directly to window 27. As shown, the assembly is bonded to window 27 by means of a layer of adhesive 28 between the window and electrode 20. It is, however, pointed out that the present invention may be equally advantageously employed in connection with fluid filled transducers, and in connection with transducers wherein the body electrode assembly is not secured to the window, but is mounted within the housing by methods which may require the use of structural acoustic decouplers.

The improvement in wide-band response afforded by the applicants unique transducer configuration is evident in FIG. 3. Curve 30 represents the sound-pressure level versus frequency characteristic of a typical transducer in accordance with the present invention. Curve 31 represents the sound-pressure level versus frequency characteristic of a typical prior art transducer designed to operate over substantially the same frequency range. It can be observed from curve 31 that the prior art transducer has a definite resonance at a frequency between F and F The sound-pressure level decreases relatively rapidly at frequencies below and above the resonant frequency.

Since a relatively constant voltage level versus frequency relationship is required for practical sonar operation, it can be observed that the operational frequency range of the prior art transducer is limited. The

useful frequency range can be somewhat extended by employing electronic compensation to boost voltages having values below a desired level, and by employing damping to reduce voltages having valuesabove the desired level. These techniques obviously involve critical design considerations, and require additional equipment which increases the complexity of resulting transducer installations. Further, although some increase in useful bandwidth can be achieved, the total available improvement is limited.

As shown by curve 30, the sound-pressure level versus frequency response of a transducer in accordance with the present invention is relatively constant, for a constant applied voltage, over a range of frequencies extending from below F to approximately F.;. This relationship extends over a considerably greater range of frequencies than that over which useful operation can be obtained from a transducer of prior art design. If required, the operational frequency range can be somewhat further extended by employing electronic compensation.

Although a single embodiment of the applicant's invention has been shown and described in detail, a variety of other embodiments and modifications are within the applicants contemplation and teaching. Such embodiments and modifications will be readily apparent to one skilled in the art having the benefit of the teachings presented in the foregoing description and drawings. Accordingly, the applicant does not intend to be limited to the disclosed embodiment, but only by the terms of the appended claims.

What is claimed is:

1. In a thickness-mode electroacoustic transducer of the type including an active body having two major surfaces, at least one of which is subdivided by means of grooves to form a two-dimensional array of poles, and electrode means for carrying electrical signals to or from the poles, the improvement which comprises an active body wherein the major surfaces are non-parallel so that said body is of non-uniform thickness.

2. The transducer of claim 1 further including a fluid tight housing having a window transparent to acoustic energy, and means for securing the assembly comprising said body and said electrode means within said housing.

3. The transducer of claim 2 wherein said body is positioned within said housing so that said poles are generally directed toward the window, said assembly being bonded to the window.

4. A wide-band thickness-mode electroacoustic transducer comprising an active body having two nonparallel major surfaces at least one of which is subdivided by means of grooves to form a two-dimensional array of poles, and electrode means for carrying electrical signals to or from said poles.

5. The transducer of claim 4 wherein said body is of tapered configuration having planar major surfaces.

6. The transducer of claim 5 wherein the grooves in one major surface of said body extend to a uniform distance from the other major surface, thereby forming poles of varying heights.

7. The transducer of claim 6 wherein the grooves are located along two sets of equally-spaced parallel lines,

each set intersecting the other so as to form a regular toward the window, said assembly being bonded to the

Claims (9)

1. In a thickness-mode electroacoustic transducer of the type including an active body having two major surfaces, at least one of which is subdivided by means of grooves to form a twodimensional array of poles, and electrode means for carrying electrical signals to or from the poles, the improvement which comprises an active body wherein the major surfaces are nonparallel so that said body is of non-uniform thickness.
2. The transducer of claim 1 further including a fluid tight housing having a window transparent to acoustic energy, and means for securing the assembly comprising said body and said electrode means within said housing.
3. The transducer of claim 2 wherein said body is positioned within said housing so that said poles are generally directed toward the window, said assembly being bonded to the window.
4. A wide-band thickness-mode electroacoustic transducer comprising an active body having two nonparallel major surfaces at least one of which is subdivided by means of grooves to form a two-dimensional array of poles, and electrode means for carrying electrical signals to or from said poles.
5. The transducer of claim 4 wherein said body is of tapered configuration having planar major surfaces.
6. The transducer of claim 5 wherein the grooves in one major surface of said body extend to a uniform distance from the other major surface, thereby forming poles of varying heights.
7. The transducer of claim 6 wherein the grooves are located along two sets of equally-spaced parallel lines, each set intersecting the other so as to form a regular pattern.
8. The transducer of claim 7 wherein said electrode means comprises metal foil bonded to the major surfaces of said body by means of an adhesive.
9. The transducer of claim 8 wherein the assembly comprising said body and said electrode means is contained within a water tIght housing having a window transparent to acoustic energy, said body being positioned so that the poles thereof are generally oriented toward the window, said assembly being bonded to the window.
US34993773 1973-04-11 1973-04-11 Wide-band electroacoustic transducer Expired - Lifetime US3833825A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US34993773 US3833825A (en) 1973-04-11 1973-04-11 Wide-band electroacoustic transducer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US34993773 US3833825A (en) 1973-04-11 1973-04-11 Wide-band electroacoustic transducer

Publications (1)

Publication Number Publication Date
US3833825A true US3833825A (en) 1974-09-03

Family

ID=23374611

Family Applications (1)

Application Number Title Priority Date Filing Date
US34993773 Expired - Lifetime US3833825A (en) 1973-04-11 1973-04-11 Wide-band electroacoustic transducer

Country Status (1)

Country Link
US (1) US3833825A (en)

Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3939467A (en) * 1974-04-08 1976-02-17 The United States Of America As Represented By The Secretary Of The Navy Transducer
EP0066876A1 (en) * 1981-06-08 1982-12-15 Kabushiki Kaisha Toshiba Ultrasonic imaging apparatus
EP0072498A1 (en) * 1981-08-18 1983-02-23 Kabushiki Kaisha Toshiba Ultrasonic imaging apparatus
EP0151003A2 (en) * 1984-01-30 1985-08-07 The Board Of Trustees Of The University Of Illinois Apparatus and method for generating and directing ultrasound
US5065068A (en) * 1989-06-07 1991-11-12 Oakley Clyde G Ferroelectric ceramic transducer
US5229748A (en) * 1989-04-12 1993-07-20 Siemens Aktiengesellschaft Monitoring system for monitoring the window panes of an interior, for example a motor vehicle interior
US5363852A (en) * 1992-06-19 1994-11-15 Advanced Cardiovascular Systems, Inc. Flow monitor and vascular access system with continuously variable frequency control
EP0641606A2 (en) * 1993-09-07 1995-03-08 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5415175A (en) * 1993-09-07 1995-05-16 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5423319A (en) * 1994-06-15 1995-06-13 Hewlett-Packard Company Integrated impedance matching layer to acoustic boundary problems for clinical ultrasonic transducers
US5434827A (en) * 1993-06-15 1995-07-18 Hewlett-Packard Company Matching layer for front acoustic impedance matching of clinical ultrasonic tranducers
US5438998A (en) * 1993-09-07 1995-08-08 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5460181A (en) * 1994-10-06 1995-10-24 Hewlett Packard Co. Ultrasonic transducer for three dimensional imaging
US5640370A (en) * 1994-01-14 1997-06-17 Acuson Corporation Two-dimensional acoustic array and method for the manufacture thereof
US5743855A (en) * 1995-03-03 1998-04-28 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5757727A (en) * 1996-04-24 1998-05-26 Acuson Corporation Two-dimensional acoustic array and method for the manufacture thereof
US5971925A (en) * 1998-06-08 1999-10-26 Acuson Corporation Broadband phased array transducer with frequency controlled two dimensional aperture capability for harmonic imaging
US5976091A (en) * 1998-06-08 1999-11-02 Acuson Corporation Limited diffraction broadband phased array transducer with frequency controlled two dimensional aperture capability
US6043589A (en) * 1997-07-02 2000-03-28 Acuson Corporation Two-dimensional transducer array and the method of manufacture thereof
US6291926B1 (en) * 1998-02-12 2001-09-18 Murata Manufacturing Co., Ltd Piezoelectric resonator, method of manufacturing the piezoelectric resonator and method of adjusting resonance frequency of the piezoelectric resonator
US6571444B2 (en) 2001-03-20 2003-06-03 Vermon Method of manufacturing an ultrasonic transducer
US6722003B2 (en) * 2001-12-12 2004-04-20 Chung-Shan Institute Of Science And Technology Underwater wide-band electroacoustic transducer and packaging method
GB2410645A (en) * 2004-01-30 2005-08-03 Smiths Group Plc Multi resonant frequency transducer for acoustic level gauging
US20080200812A1 (en) * 2007-02-21 2008-08-21 Fujifilm Corporation Ultrasonic probe
DE102008024856A1 (en) * 2008-05-23 2009-11-26 Biotronik Crm Patent Ag Piezoelectric transducer for use in piezoelectric transformer, has ceramic body exhibiting piezoelectric effect in polarization direction, where body has different thicknesses in regions in polarization direction
EP2450111A1 (en) * 2010-11-04 2012-05-09 Samsung Medison Co., Ltd. Ultrasound probe including ceramic layer formed with ceramic elements having different thickness and ultrasound system using the same
US20130021305A1 (en) * 2011-07-19 2013-01-24 Qualcomm Mems Technologies, Inc. Piezoelectric laterally vibrating resonator structure geometries for spurious frequency suppression
US20140082907A1 (en) * 2012-04-13 2014-03-27 Ardent Sound, Inc. Thick Film Transducer Arrays
US8764664B2 (en) 2005-11-28 2014-07-01 Vizyontech Imaging, Inc. Methods and apparatus for conformable medical data acquisition pad and configurable imaging system
CN104665871A (en) * 2013-11-29 2015-06-03 精工爱普生株式会社 Ultrasonic device, probe, electronic equipment, and ultrasonic image device
WO2018229735A1 (en) 2017-06-16 2018-12-20 Universidade Do Minho High frequency wideband wide beam ultrasound emitter transducer for underwater communications

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2159891A (en) * 1934-06-22 1939-05-23 Guerbilsky Alexis Electromechanical resonator
US2261791A (en) * 1939-04-29 1941-11-04 Rca Corp Piezoelectric thickness-mode quartz crystal
US2485722A (en) * 1945-01-31 1949-10-25 Gen Motors Corp Crystal
US2543500A (en) * 1946-06-27 1951-02-27 Gen Motors Corp Means for suppressing transverse modes of oscillation in a piezoelectric crystal
US3277451A (en) * 1963-11-21 1966-10-04 Edwin J Parssinen Wide angle broad band hydrophone array
US3496617A (en) * 1967-11-08 1970-02-24 Us Navy Technique for curving piezoelectric ceramics
US3593257A (en) * 1968-06-14 1971-07-13 Dynamics Corp America Electroacoustic transducer
US3718898A (en) * 1971-12-13 1973-02-27 Us Navy Transducer

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2159891A (en) * 1934-06-22 1939-05-23 Guerbilsky Alexis Electromechanical resonator
US2261791A (en) * 1939-04-29 1941-11-04 Rca Corp Piezoelectric thickness-mode quartz crystal
US2485722A (en) * 1945-01-31 1949-10-25 Gen Motors Corp Crystal
US2543500A (en) * 1946-06-27 1951-02-27 Gen Motors Corp Means for suppressing transverse modes of oscillation in a piezoelectric crystal
US3277451A (en) * 1963-11-21 1966-10-04 Edwin J Parssinen Wide angle broad band hydrophone array
US3496617A (en) * 1967-11-08 1970-02-24 Us Navy Technique for curving piezoelectric ceramics
US3593257A (en) * 1968-06-14 1971-07-13 Dynamics Corp America Electroacoustic transducer
US3718898A (en) * 1971-12-13 1973-02-27 Us Navy Transducer

Cited By (50)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3939467A (en) * 1974-04-08 1976-02-17 The United States Of America As Represented By The Secretary Of The Navy Transducer
EP0066876A1 (en) * 1981-06-08 1982-12-15 Kabushiki Kaisha Toshiba Ultrasonic imaging apparatus
EP0140392A2 (en) * 1981-06-08 1985-05-08 Kabushiki Kaisha Toshiba Ultrasonic imaging apparatus
EP0140392A3 (en) * 1981-06-08 1985-07-17 Kabushiki Kaisha Toshiba Ultrasonic imaging apparatus
EP0072498A1 (en) * 1981-08-18 1983-02-23 Kabushiki Kaisha Toshiba Ultrasonic imaging apparatus
US4478085A (en) * 1981-08-18 1984-10-23 Tokyo Shibaura Denki Kabushiki Kaisha Ultrasound diagnosis apparatus
EP0151003A2 (en) * 1984-01-30 1985-08-07 The Board Of Trustees Of The University Of Illinois Apparatus and method for generating and directing ultrasound
US4549533A (en) * 1984-01-30 1985-10-29 University Of Illinois Apparatus and method for generating and directing ultrasound
EP0151003A3 (en) * 1984-01-30 1986-08-20 University Of Illinois Apparatus and method for generating and directing ultrasound
US5229748A (en) * 1989-04-12 1993-07-20 Siemens Aktiengesellschaft Monitoring system for monitoring the window panes of an interior, for example a motor vehicle interior
US5065068A (en) * 1989-06-07 1991-11-12 Oakley Clyde G Ferroelectric ceramic transducer
US5363852A (en) * 1992-06-19 1994-11-15 Advanced Cardiovascular Systems, Inc. Flow monitor and vascular access system with continuously variable frequency control
US5434827A (en) * 1993-06-15 1995-07-18 Hewlett-Packard Company Matching layer for front acoustic impedance matching of clinical ultrasonic tranducers
US5438554A (en) * 1993-06-15 1995-08-01 Hewlett-Packard Company Tunable acoustic resonator for clinical ultrasonic transducers
US5582177A (en) * 1993-09-07 1996-12-10 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5976090A (en) * 1993-09-07 1999-11-02 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5415175A (en) * 1993-09-07 1995-05-16 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5438998A (en) * 1993-09-07 1995-08-08 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
EP0641606A2 (en) * 1993-09-07 1995-03-08 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
EP0641606A3 (en) * 1993-09-07 1996-06-12 Acuson Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof.
US5764596A (en) * 1994-01-14 1998-06-09 Acounson Corporation Two-dimensional acoustic array and method for the manufacture thereof
US5640370A (en) * 1994-01-14 1997-06-17 Acuson Corporation Two-dimensional acoustic array and method for the manufacture thereof
US5894646A (en) * 1994-01-14 1999-04-20 Acuson Corporation Method for the manufacture of a two dimensional acoustic array
US5423319A (en) * 1994-06-15 1995-06-13 Hewlett-Packard Company Integrated impedance matching layer to acoustic boundary problems for clinical ultrasonic transducers
US5460181A (en) * 1994-10-06 1995-10-24 Hewlett Packard Co. Ultrasonic transducer for three dimensional imaging
US5743855A (en) * 1995-03-03 1998-04-28 Acuson Corporation Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US5757727A (en) * 1996-04-24 1998-05-26 Acuson Corporation Two-dimensional acoustic array and method for the manufacture thereof
US6691387B2 (en) 1997-07-02 2004-02-17 Acuson Coporation Method of using a two-dimensional transducer array
US6415485B1 (en) 1997-07-02 2002-07-09 Acuson Corporation Method of manufacturing a two-dimensional transducer array
US6043589A (en) * 1997-07-02 2000-03-28 Acuson Corporation Two-dimensional transducer array and the method of manufacture thereof
US6291926B1 (en) * 1998-02-12 2001-09-18 Murata Manufacturing Co., Ltd Piezoelectric resonator, method of manufacturing the piezoelectric resonator and method of adjusting resonance frequency of the piezoelectric resonator
US5976091A (en) * 1998-06-08 1999-11-02 Acuson Corporation Limited diffraction broadband phased array transducer with frequency controlled two dimensional aperture capability
US5971925A (en) * 1998-06-08 1999-10-26 Acuson Corporation Broadband phased array transducer with frequency controlled two dimensional aperture capability for harmonic imaging
US6571444B2 (en) 2001-03-20 2003-06-03 Vermon Method of manufacturing an ultrasonic transducer
US6722003B2 (en) * 2001-12-12 2004-04-20 Chung-Shan Institute Of Science And Technology Underwater wide-band electroacoustic transducer and packaging method
US6750595B2 (en) * 2001-12-12 2004-06-15 Chung-Shan Institute Of Science And Technology Underwater wide-band electroacoustic transducer and packaging method
US20050166672A1 (en) * 2004-01-30 2005-08-04 Smiths Group Plc Acoustic devices and fluid gauging
GB2410645A (en) * 2004-01-30 2005-08-03 Smiths Group Plc Multi resonant frequency transducer for acoustic level gauging
US8764664B2 (en) 2005-11-28 2014-07-01 Vizyontech Imaging, Inc. Methods and apparatus for conformable medical data acquisition pad and configurable imaging system
US20080200812A1 (en) * 2007-02-21 2008-08-21 Fujifilm Corporation Ultrasonic probe
US8961422B2 (en) * 2007-02-21 2015-02-24 Fujifilm Corporation Ultrasonic probe
DE102008024856A1 (en) * 2008-05-23 2009-11-26 Biotronik Crm Patent Ag Piezoelectric transducer for use in piezoelectric transformer, has ceramic body exhibiting piezoelectric effect in polarization direction, where body has different thicknesses in regions in polarization direction
EP2450111A1 (en) * 2010-11-04 2012-05-09 Samsung Medison Co., Ltd. Ultrasound probe including ceramic layer formed with ceramic elements having different thickness and ultrasound system using the same
US20130021305A1 (en) * 2011-07-19 2013-01-24 Qualcomm Mems Technologies, Inc. Piezoelectric laterally vibrating resonator structure geometries for spurious frequency suppression
US8816567B2 (en) * 2011-07-19 2014-08-26 Qualcomm Mems Technologies, Inc. Piezoelectric laterally vibrating resonator structure geometries for spurious frequency suppression
US20140082907A1 (en) * 2012-04-13 2014-03-27 Ardent Sound, Inc. Thick Film Transducer Arrays
US9263663B2 (en) * 2012-04-13 2016-02-16 Ardent Sound, Inc. Method of making thick film transducer arrays
CN104665871A (en) * 2013-11-29 2015-06-03 精工爱普生株式会社 Ultrasonic device, probe, electronic equipment, and ultrasonic image device
US20150150533A1 (en) * 2013-11-29 2015-06-04 Seiko Epson Corporation Ultrasonic device, probe, electronic equipment, and ultrasonic image device
WO2018229735A1 (en) 2017-06-16 2018-12-20 Universidade Do Minho High frequency wideband wide beam ultrasound emitter transducer for underwater communications

Similar Documents

Publication Publication Date Title
US3321648A (en) Piezoelectric filter element
US3325780A (en) Flexural transducers
US4616152A (en) Piezoelectric ultrasonic probe using an epoxy resin and iron carbonyl acoustic matching layer
US6104126A (en) Composite transducer with connective backing block
US5303210A (en) Integrated resonant cavity acoustic transducer
US4385255A (en) Linear array ultrasonic transducer
US4413198A (en) Piezoelectric transducer apparatus
US4671293A (en) Biplane phased array for ultrasonic medical imaging
CN1046058C (en) An ultrasound transducer array and manufacturing method thereof
US4383194A (en) Electro-acoustic transducer element
CA1260603A (en) Ultrasound transducer
EP0145429B1 (en) Curvilinear array of ultrasonic transducers
US4680499A (en) Piezoelectric ultrasonic transducer with acoustic matching plate
US3941946A (en) Electrostatic transducer assembly
US3699484A (en) Width extensional resonator and coupled mode filter
EP0037620A1 (en) Acoustic impedance matching device
US5651365A (en) Phased array transducer design and method for manufacture thereof
US4419545A (en) Electret transducer
US6617765B1 (en) Underwater broadband acoustic transducer
US5706820A (en) Ultrasonic transducer with reduced elevation sidelobes and method for the manufacture thereof
US3510698A (en) Electroacoustical transducer
US5711058A (en) Method for manufacturing transducer assembly with curved transducer array
EP0027542B1 (en) Ultrasonic transducer element
JP3852949B2 (en) Ultrasonic transducer
US5115810A (en) Ultrasonic transducer array

Legal Events

Date Code Title Description
AS Assignment

Owner name: ALLIANT TECHSYSTEMS INC., MINNESOTA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:HONEYWELL INC. A CORP. OF DELAWARE;REEL/FRAME:005845/0384

Effective date: 19900924