EP0401027A2 - An acoustic transducer - Google Patents
An acoustic transducer Download PDFInfo
- Publication number
- EP0401027A2 EP0401027A2 EP90305961A EP90305961A EP0401027A2 EP 0401027 A2 EP0401027 A2 EP 0401027A2 EP 90305961 A EP90305961 A EP 90305961A EP 90305961 A EP90305961 A EP 90305961A EP 0401027 A2 EP0401027 A2 EP 0401027A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- piezoelectric
- transducer
- aperture
- piezoelectric material
- distribution
- 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.)
- Withdrawn
Links
- 239000004593 Epoxy Substances 0.000 claims abstract description 5
- 239000000463 material Substances 0.000 claims description 12
- 239000000919 ceramic Substances 0.000 claims description 5
- 230000001419 dependent effect Effects 0.000 claims description 2
- 230000005284 excitation Effects 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 abstract 2
- 239000002131 composite material Substances 0.000 abstract 1
- 238000000034 method Methods 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000026683 transduction Effects 0.000 description 1
- 238000010361 transduction Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
- B06B1/0629—Square array
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
- Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
Abstract
In order to reduce side lobes in the transmission characteristics of an acoustic transducer the amplitude of transmission is tapered towards the edges of the aperture. This is done by constructing the transducer from ceramic-epoxy composite elements connected in a one-three configuration and distributed with varying volume fraction in the width and length directions.
Description
- This invention relates to an acoustic transducer.
- It has previously been proposed to construct acoustic transducers using an array of ceramic pillars embedded in an epoxy. The effect of the epoxy is to improve acoustic matching to liquid-based loads and to increase bandwidth. Also, the use of a pillar-like transducer improves transduction efficiency.
- The invention arose as a result of research into techniques for controlling the beam-shape (in particular for eliminating side lobes) in the radiation pattern of an acoustic transducer. Such control is normally achieved by applying a apodisation function to individual transducers across an array. Doing this requires complicated and expensive driving circuitry and also requires individual connections to be made to each element in the array. The inventors have now realised that this problem can be overcome using the technique described in the immediately preceding paragraph.
- The invention provides an acoustic transducer comprising a layer of piezoelectric and non-piezoelectric material distributed across an aperture of the transducer and electrode means on each side of the layer for applying an input signal to it or receiving an output signal from it; the manner of distribution of the piezoelectric and non-piezoelectric being such that the amplitude of vibration caused by a given input signal (or the amplitude of an output signal caused by a given variation) is dependent on a control function defined by (a) the percentage and/or distribution and/or type of piezoelectric material and/or (b) the percentage and/or distribution and/or type of non-piezoelectric material, characterised in that the said function varies across the aperture.
- By varying the aforementioned control function in this way, the required apodisation characteristics can be obtained from a single excitation source and the individual connections can be made using just two electrodes.
- The control function can be varied in a number of different ways, for example by varying:-
- (1) the proportion of the area of the aperture which is piezoelectric,
- (2) the type of piezoelectric or non-piezoelectric used at different parts of the aperture, or
- (3) the shape of piezoelectric or non-piezoelectric parts.
- One possible construction comprises an array of individual peizoelectric elements seperated by a matrix of non-piezoelectric material. Alternative possibilities include using a single piezoelectric slab formed with holes into which non-piezoelectric is loaded. Another possibility would be to use a honeycomb or sponge-like structure of piezoelectric filled with non-piezoelectric or vice-versa. Another possibility would be to mix piezoelectric and non-piezoelectric, e.g. by powdering a ceramic piezoelectric material and mixing it with a suitable non-piezoelectric filler.
- Another possible way of varying the aforementioned "function" would be to change the shape of the piezoelectric or non-piezoelectric parts across the aperture.
- For ease of construction it is convenient to form the array from a number of blocks, the "function" being uniform for each block.
- One way of performing the invention will now be described by way of example with reference to the accompanying drawings, in which:
- Figure 1 shows a plan view of a transducer constructed in accordance with the invention;
- Figure 2 is a graphical illustration of the amplitude of acoustic energy transmitted from the different parts of the transducer shown in Figure 1; and
- Figure 3 is a cross-section through the line III-III of Figure 1.
- The illustrated transducer comprises nine blocks, 1, 2A, 2B, 3A, 3B, 4A, 4B, 5A and 5B. Each block is individually made and the blocks are located together as shown.
- Each block comprises a number of ceramic piezoelectric pillars, e.g. as shown at 5. These are made of a commonly used material, namely lead-zirconate-titanate type ceramic. The pillars are embedded in a hard-setting epoxy using established slice-and-fill techniques. The individual blocks are held together by adhesive and opposite sides are then coated with metallic paint to form electrodes 6 and 7.
- It will be noted from Figure 1 that the pillars are approximately evenly distributed over the area of each block but that their spacing is greater in blocks towards the outside. For this reason, the amplitude of radiated energy as shown in Figure 2 is greatest from the
centre block 1 and least from theouter blocks - In operation as a transmitter, electric signals from
circuitry 8 are applied to thepillars 5 via the electrodes 6 and 7 to transmit a desired acoustic signal in the direction shown by the arrow on Figure 3. The electrode 7 is mounted on a rigid substrate preventing substantial radiation in the opposite direction. In operation as a receiver, acoustic energy causes thepillar 5 to generate a potential difference across electrodes 6 and 7, and this is detected at 8. In both modes of operation, the tapering volume fraction (values given on Figure 1) across the width of the acoustic aperture gives the gain pattern of the transducer a pronounced main lobe and reduced side lobes. Of course, in other environments, a similar technique could be used to obtain given patterns having other characteristics, e.g. two main lobes or omnidirectional radiation and reception.
Claims (4)
1. An acoustic transducer comprising a layer of piezoelectric and non-piezoelectric material distributed across an aperture of the transducer, and electrode means on each side of the layer for applying an input signal to it or receiving an output signal from it; the manner of distribution of the piezoelectric and non-piezoelectric being such that the amplitude of vibration caused by given input signals (or the amplitude of an output signal caused by a given vibration) is dependent on a control function defined by (a) the percentage and/or distribution and/or type of piezoelectric material and/or (b) the percentage and/or distribution and/or type of non piezoelectric material, characterised in that the said function varies across the aperture.
2. A transducer according to claim 1 comprising a number of blocks of elements, the said function being uniform across each block but varying between adjacent blocks.
3. A transducer according to claim 1 or 2 comprising pillars of ceramic piezoelectric material embedded in an epoxy material.
4. A transducer according to any preceding claim comprising two electrodes making contact with the piezoelectric material across the aperture of the transduceri and a single excitation source or receiver connected to the electrodes.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB898912782A GB8912782D0 (en) | 1989-06-02 | 1989-06-02 | An acoustic transducer |
GB8912782 | 1989-06-02 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0401027A2 true EP0401027A2 (en) | 1990-12-05 |
EP0401027A3 EP0401027A3 (en) | 1992-01-08 |
Family
ID=10657817
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19900305961 Withdrawn EP0401027A3 (en) | 1989-06-02 | 1990-05-31 | An acoustic transducer |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0401027A3 (en) |
JP (1) | JPH03113999A (en) |
CA (1) | CA2017382A1 (en) |
GB (2) | GB8912782D0 (en) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5371717A (en) * | 1993-06-15 | 1994-12-06 | Hewlett-Packard Company | Microgrooves for apodization and focussing of wideband clinical ultrasonic transducers |
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 |
US5460181A (en) * | 1994-10-06 | 1995-10-24 | Hewlett Packard Co. | Ultrasonic transducer for three dimensional imaging |
US5465725A (en) * | 1993-06-15 | 1995-11-14 | Hewlett Packard Company | Ultrasonic probe |
EP0689187A1 (en) * | 1994-06-24 | 1995-12-27 | Advanced Technology Laboratories, Inc. | Ultrasonic diagnostic transducer array with elevation focus |
EP0707898A2 (en) * | 1994-10-21 | 1996-04-24 | Hewlett-Packard Company | Method of forming integral transducer and impedance matching layers |
US5546946A (en) * | 1994-06-24 | 1996-08-20 | Advanced Technology Laboratories, Inc. | Ultrasonic diagnostic transducer array with elevation focus |
DE102006015493A1 (en) * | 2006-04-03 | 2007-10-11 | Atlas Elektronik Gmbh | Electroacoustic transducer |
ITGE20100018A1 (en) * | 2010-02-23 | 2011-08-24 | Esaote Spa | ULTRASOUND PROBE |
WO2012131212A1 (en) | 2011-03-30 | 2012-10-04 | Edap Tms France | Method and apparatus for generating focused ultrasonic waves with surface modulation |
EP2796209A3 (en) * | 2013-04-25 | 2015-06-10 | Canon Kabushiki Kaisha | Capacitive transducer and method of manufacturing the same |
US9683971B2 (en) | 2013-04-25 | 2017-06-20 | Canon Kabushiki Kaisha | Object information acquiring apparatus and control method thereof |
US10293374B2 (en) | 2013-04-25 | 2019-05-21 | Canon Kabushiki Kaisha | Capacitive transducer and method of manufacturing same |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4413568B2 (en) * | 2003-09-19 | 2010-02-10 | パナソニック株式会社 | Ultrasonic probe |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2114857A (en) * | 1982-02-16 | 1983-08-24 | Gen Electric | Ultrasonic transducer shading |
DE3334090A1 (en) * | 1982-09-22 | 1984-03-22 | North American Philips Corp., 10017 New York, N.Y. | APODIZED ULTRASONIC transducer |
EP0137529A2 (en) * | 1983-08-15 | 1985-04-17 | Koninklijke Philips Electronics N.V. | Method for fabricating composite electrical transducers |
GB2190818A (en) * | 1986-05-07 | 1987-11-25 | Brueel & Kjaer As | An ultrasonic transducer for providing a desired sound field |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2006434B (en) * | 1977-10-20 | 1982-03-03 | Rca Corp | Switchable depth of focus pulse-echo ultra-sonic imaging display system |
GB2095951A (en) * | 1981-02-19 | 1982-10-06 | Nat Res Dev | Transducers of improved resolution and systems for the transmission and reception of radiation |
-
1989
- 1989-06-02 GB GB898912782A patent/GB8912782D0/en active Pending
-
1990
- 1990-05-23 CA CA 2017382 patent/CA2017382A1/en not_active Abandoned
- 1990-05-31 GB GB9012171A patent/GB2232323A/en not_active Withdrawn
- 1990-05-31 EP EP19900305961 patent/EP0401027A3/en not_active Withdrawn
- 1990-06-01 JP JP14426390A patent/JPH03113999A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2114857A (en) * | 1982-02-16 | 1983-08-24 | Gen Electric | Ultrasonic transducer shading |
DE3334090A1 (en) * | 1982-09-22 | 1984-03-22 | North American Philips Corp., 10017 New York, N.Y. | APODIZED ULTRASONIC transducer |
EP0137529A2 (en) * | 1983-08-15 | 1985-04-17 | Koninklijke Philips Electronics N.V. | Method for fabricating composite electrical transducers |
GB2190818A (en) * | 1986-05-07 | 1987-11-25 | Brueel & Kjaer As | An ultrasonic transducer for providing a desired sound field |
Non-Patent Citations (1)
Title |
---|
ultrasonics international 87 conf. proc., london6-9 july 1987, p. 426-431, D. J. Mehrl et al. : "Design and evaluation of apodized piezo__ electric transducers" * |
Cited By (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5371717A (en) * | 1993-06-15 | 1994-12-06 | Hewlett-Packard Company | Microgrooves for apodization and focussing of wideband clinical ultrasonic transducers |
EP0629992A2 (en) * | 1993-06-15 | 1994-12-21 | Hewlett-Packard Company | Micro-grooves for apodization and focussing of wideband 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 |
US5438554A (en) * | 1993-06-15 | 1995-08-01 | Hewlett-Packard Company | Tunable acoustic resonator for clinical ultrasonic transducers |
EP0629992A3 (en) * | 1993-06-15 | 1995-10-25 | Hewlett Packard Co | Micro-grooves for apodization and focussing of wideband clinical ultrasonic transducers. |
US5465725A (en) * | 1993-06-15 | 1995-11-14 | Hewlett Packard Company | Ultrasonic probe |
US5423319A (en) * | 1994-06-15 | 1995-06-13 | Hewlett-Packard Company | Integrated impedance matching layer to acoustic boundary problems for clinical ultrasonic transducers |
EP0689187A1 (en) * | 1994-06-24 | 1995-12-27 | Advanced Technology Laboratories, Inc. | Ultrasonic diagnostic transducer array with elevation focus |
US5546946A (en) * | 1994-06-24 | 1996-08-20 | Advanced Technology Laboratories, Inc. | Ultrasonic diagnostic transducer array with elevation focus |
US5460181A (en) * | 1994-10-06 | 1995-10-24 | Hewlett Packard Co. | Ultrasonic transducer for three dimensional imaging |
EP0707898A2 (en) * | 1994-10-21 | 1996-04-24 | Hewlett-Packard Company | Method of forming integral transducer and impedance matching layers |
EP0707898A3 (en) * | 1994-10-21 | 1997-07-23 | Hewlett Packard Co | Method of forming integral transducer and impedance matching layers |
DE102006015493A1 (en) * | 2006-04-03 | 2007-10-11 | Atlas Elektronik Gmbh | Electroacoustic transducer |
DE102006015493B4 (en) * | 2006-04-03 | 2010-12-23 | Atlas Elektronik Gmbh | Electroacoustic transducer |
ITGE20100018A1 (en) * | 2010-02-23 | 2011-08-24 | Esaote Spa | ULTRASOUND PROBE |
WO2012131212A1 (en) | 2011-03-30 | 2012-10-04 | Edap Tms France | Method and apparatus for generating focused ultrasonic waves with surface modulation |
FR2973550A1 (en) * | 2011-03-30 | 2012-10-05 | Edap Tms France | METHOD AND APPARATUS FOR GENERATING FOCUSED ULTRASONIC WAVE WITH SURFACE MODULATION |
CN103650031A (en) * | 2011-03-30 | 2014-03-19 | Edaptms法国公司 | Method and apparatus for generating focused ultrasonic waves with surface modulation |
CN103650031B (en) * | 2011-03-30 | 2016-08-31 | Edaptms法国公司 | Surface modulation is utilized to produce the method and apparatus focusing on ultrasonic wave |
US9936969B2 (en) | 2011-03-30 | 2018-04-10 | Edap Tms France | Method and apparatus for generating focused ultrasonic waves with surface modulation |
EP2796209A3 (en) * | 2013-04-25 | 2015-06-10 | Canon Kabushiki Kaisha | Capacitive transducer and method of manufacturing the same |
US9683971B2 (en) | 2013-04-25 | 2017-06-20 | Canon Kabushiki Kaisha | Object information acquiring apparatus and control method thereof |
US10189049B2 (en) | 2013-04-25 | 2019-01-29 | Canon Kabushiki Kaisha | Capacitive transducer and method of manufacturing same |
US10293374B2 (en) | 2013-04-25 | 2019-05-21 | Canon Kabushiki Kaisha | Capacitive transducer and method of manufacturing same |
Also Published As
Publication number | Publication date |
---|---|
JPH03113999A (en) | 1991-05-15 |
GB9012171D0 (en) | 1990-07-18 |
EP0401027A3 (en) | 1992-01-08 |
GB8912782D0 (en) | 1989-07-19 |
CA2017382A1 (en) | 1990-12-02 |
GB2232323A (en) | 1990-12-05 |
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18D | Application deemed to be withdrawn |
Effective date: 19920709 |