JP3478874B2 - Ultrasonic phased array converter and method of manufacturing the same - Google Patents

Ultrasonic phased array converter and method of manufacturing the same

Info

Publication number
JP3478874B2
JP3478874B2 JP19920094A JP19920094A JP3478874B2 JP 3478874 B2 JP3478874 B2 JP 3478874B2 JP 19920094 A JP19920094 A JP 19920094A JP 19920094 A JP19920094 A JP 19920094A JP 3478874 B2 JP3478874 B2 JP 3478874B2
Authority
JP
Japan
Prior art keywords
transducer
thickness
piezoelectric
element
array
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
JP19920094A
Other languages
Japanese (ja)
Other versions
JPH07107595A (en
Inventor
エム ハナフィ アミン
エイチ マスラク サミュエル
エス プルージ ジェイ
Original Assignee
アキューソン コーポレイション
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
Priority to US08/117868 priority Critical
Priority to US08/117869 priority
Priority to US08/117,868 priority patent/US5415175A/en
Priority to US08/117,869 priority patent/US5438998A/en
Application filed by アキューソン コーポレイション filed Critical アキューソン コーポレイション
Publication of JPH07107595A publication Critical patent/JPH07107595A/en
Application granted granted Critical
Publication of JP3478874B2 publication Critical patent/JP3478874B2/en
Anticipated expiration legal-status Critical
Application status is Expired - Lifetime legal-status Critical

Links

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
    • B06B1/0607Methods 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 multiple elements
    • B06B1/0622Methods 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 multiple elements on one surface
    • 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
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00Piezo-electric transducers; Electrostrictive transducers
    • H04R17/04Gramophone pick-ups using a stylus; Recorders using a stylus
    • H04R17/08Gramophone pick-ups using a stylus; Recorders using a stylus signals being recorded or played back by vibration of a stylus in two orthogonal directions simultaneously

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter, and more particularly to a converter.
Broadband phase used in the field of medical diagnostics
Related to an array transducer. [0002] 2. Description of the Related Art Ultrasound apparatus for observing human organs
Is often used. Typically, these devices
Includes transducer array that converts electrical signals to pressure waves
You. In general, a transducer array focuses an ultrasonic beam on a region of interest.
The shape of a hand-held probe that can be positioned to guide
You. The transducer array is used to generate an ultrasonic beam,
For example, it can have 128 transducer elements. conversion
Electrodes are arranged at the front and rear of the
The elements are individually excited to generate pressure waves. To the transducer element
The resulting pressure wave looks like the heart of the patient being examined.
Is guided to the target to be observed. Acoustic characteristics with different pressure waves
Each time it hits sexual tissue, the wave is reflected back.
An array of transducers converts these reflected pressure waves into corresponding electrical signals.
Convert to issue. Conventional phased array acoustic imaging device
An example is the US patent of Maslak et al. Dated November 5, 1985.
No. 4,550,607. Shown in this patent
Circuit combines the input signals received by the transducer array.
To generate a focused image on the display screen. Broadband transformation
Can operate over a wide range of frequencies without loss of sensitivity
It is a simple converter. Broadband converter operates over a wide band
Results in improved resolution along the range axis
Image quality is further improved. [0003] One possible application of a wideband converter is harmonics.
This is contrast harmonic imaging. Key
Wave contrast imaging is like microballoons of protein spheres
Safely inject contrast material into the body, like a heart
To show how active the organization is
You. The diameter of these microballoons is typically
5 μm, and when injected into the body,
Supersonic to determine how well it is working
It can be observed by wave imaging. Harmonic contrast imaging
Computer with radioactive material injected into the body
Of thallium test method for observing tomographic images generated by laser
It is. The thallium test method states that they are potentially harmful
To generate computer images using radioactive materials
Typically requires at least one hour,
Not a good one. Using secure micro balloons
In addition to harmonic contrast, real-time ultrasound technology can be used
This is different from the imaging method. Ultrasonic
 Papers on pages 134-158 of Imaging, Vol. 14 (1992)
“SimulatedCapillary Blood Flow Measurement Using
a. Nonlinear Ultrasonic ContrastAgent
 Schrope et al. Clearly contrast materials at the second harmonic.
It discloses that it can be observed. That is, the fundamental harmonic
And clear observation of heart and muscle tissue by ultrasonic technology
Is done. However, at the second harmonic,
The strike material itself can be clearly observed, and
Determine how well each organization is performing
It can be done. [0004] In the harmonic contrast imaging method, the converter is used for a wide frequency range.
At the wave number (ie, both the fundamental and the second harmonic)
Must be able to work, but typically with existing converters
Cannot function in such a wide range. example
For example, if the center frequency is 5 MHz, the band for the center frequency
Transducer with 70% width ratio has 3.25 MHz bandwidth
To 6.75 MHz. If the fundamental harmonic is 3.5 MH
For z, the second harmonic is 7.0 MHz. Follow
A transducer with a center frequency of 5 MHz is
And can work well at both
Absent. Need for transducers that can operate over a wide range of frequencies
In addition, to improve the resolution of the generated image, two-dimensional transformation
A heat exchanger array is also desired. An example of a two-dimensional transducer array is
 Haan US Patent 3,833,825 dated October 3, 1974
Issue. Two-dimensional arrays are common one-dimensional
Along the axis of elevation not used for rays
The control of the excitation of the ultrasonic beam can be improved.
However, typically a two-dimensional array has each element
Cut into several segments along
Because it is necessary to connect the lead for excitation,
Difficult to manufacture. For example, 128 in the azimuthal axis
The two-dimensional array having the elements of
At least 256 segments in total
Requires leads to interconnect these segments
Let's say In addition, at least twice as large as one-dimensional arrays
Volume of segments exist and these must be excited individually.
At some appropriate point during the ultrasound scan.
A fairly complex software to excite each segment of
Wear is required. [0005] Further, it has a plane parallel to the object to be inspected.
Typical prior art transducers include a transducer and a device under test.
Called "ghost echo" at the interface between
Generates unwanted reflections. Of these unwanted reflections
Therefore, the clarity of the obtained image decreases. [0006] SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an
Inexpensive and widely used in acoustic imaging devices
To provide a band translation array. Another of the present invention
The purpose is a wideband that can be used for harmonic contrast imaging
The purpose is to provide a transducer array. Another object of the present invention
Have both negative curvatures that give additional focus to the area of interest.
Providing a matching transducer element and matching layer.
Another object of the present invention is to provide at least lower frequencies.
Move closer to the two-dimensional transducer array.
Can be used in acoustic imaging devices that can
It is to provide a transducer array that can be used. Of the present invention
Yet another object is to provide an undesired surface on the inspected object.
It is to better suppress the generation of reflections. The present invention
Another objective is to apply one or more matching layers to the inspected area.
On the front part of the piezoelectric layer facing the area
To further increase the sensitivity and bandwidth of the transducer.
You. [0007] To achieve the above object, the present invention
Some preferred embodiments are provided. First embodiment of the present invention
Example array type ultrasonic transducers are placed in contact with each other.
A plurality of transducer elements. Each element is inspected area
Front part, rear part, two side parts, front part facing the area
Having a transducer thickness between the part and the rear part. conversion
The container thickness is the maximum thickness in the side part, the two side parts
Minimum thickness in minutes. Furthermore, the maximum thickness
Is less than or equal to 140% of the minimum thickness
No. In this embodiment, the bandwidth is increased and the pulse width is reduced.
The thickness of the element along the distance (Z) axis should be between 20 and 4
0% (that is, the maximum thickness is
 120 to 140%). this
This improves the resolution along the distance axis. Second embodiment of the present invention
Generates an ultrasonic beam when excited
The transducer comprises a plurality of piezoelectric elements. Each element is
At least at a first point on the surface facing the inspection area
Thickness at least at a second point on the surface
And the surface is non-planar. Furthermore, the present invention
The aperture (aperture) of the ultrasonic beam generated by
It changes inversely with the excitation frequency of the element. Generally, piezoelectric
Maximum element thickness is greater than 140% of minimum piezoelectric element thickness
In critical cases, the transducer is quadratic at lower frequencies.
Generate a beam close to the beam generated by the original array
be able to. This is a converter at lower frequencies
Output pressure wave has at least two peaks
Is based on the fact that At lower frequencies
Typically, the full aperture is activated. Therefore, this second
Embodiments approach the excitation of a wide aperture two-dimensional transducer array. In a third embodiment, a two-crystal transducer element design is used.
Provided. This design comprises a first piezoelectric part,
A small portion of the first piezoelectric portion on the first surface facing the region to be inspected.
The thickness at least at one point is less than the thickness on the first surface.
At least smaller than the thickness at one other point, the first
The surface is non-planar. First and second piezoelectric parts
And an interconnect circuit can be arranged between them. First
A matching layer can be arranged on the piezoelectric part. Fourth fruit
In the example, a composite structural modification with multiple vertical columns of piezoelectric material is used.
A converter is provided, the distance between the columns of the converter and the polymer layer
Changes. This structure is used to obtain the desired transducer configuration.
Can be deformed. In addition, the structure of this composite converter
Performance is further improved by placing a matching layer on the
be able to. The converters of all of the above embodiments have a wide frequency range.
Operable in a few ranges and correct apodization
(Apodization). These examples
Does the rear acoustic port of the element need to be matched?
Generally these are easier to assemble than prior art devices
It is. First Preferred Method of the Invention for Manufacturing a Transducer
Is formed by arranging multiple transducer elements in contact with each other
Consisting of Each element is the front part facing the inspection area
Between the rear part, the two side parts, and the front and rear parts
Of the transducer thickness. Furthermore, the transducer thickness is
Section is the largest thickness, between the two side sections
Is the minimum thickness, and the maximum thickness is 1
Less than or equal to 40%. At least each element
An electric field through one part is also established. A second preferred embodiment of the present invention for manufacturing a transducer
The method comprises forming a plurality of piezoelectric elements. Each point
At least one on the front surface facing the element to be inspected
The thickness at a point is at least one other on the surface.
Smaller than the thickness at the point, the surface is non-planar
You. An electric field through at least one portion of each element is established.
It is. For example, electrodes are placed on the front and back of each piezoelectric element.
Provided to apply an electric field. Typically, piezoelectric
The maximum thickness of the element is greater than 140% of the minimum thickness of the piezoelectric element
When the excitation pulse is applied to the electrode,
The aperture of the generated ultrasonic beam depends on the frequency of the excitation pulse.
And change in reverse. A third aspect of the present invention for manufacturing a transducer.
A preferred method is to provide a composite having a front portion facing the area to be inspected.
Forming a piezoelectric element made of a composite material. the above
The thickness of at least one point on the front part is less on the front part
At least less than the thickness of one other point. First and second
Of the electrodes can be arranged on the piezoelectric element. Element is where
It can be deformed to the desired shape. Modifications of all embodiments
The converter and the converter manufactured by the above method are hand-held
The shape of the probe.
The beam can be directed to a region of interest. In addition, all real
Example converter and converter manufactured by the above method
Inside the housing for placement in the handheld probe
Can be arranged. Other types of probes and beams
Can be considered. Ultrasound equipment that generates images
A transmitter circuit for transmitting an electrical signal to the transducer probe, and a converter
Receiving circuit for processing the signal received by the detector probe,
And a display device for generating an image to be viewed. The converter is
The electric signal supplied from the transmission circuit is converted into a pressure wave,
Converts pressure waves reflected from the observation target into corresponding electrical signals
I do. These electrical signals are processed in a receiving circuit,
It is finally displayed. [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG.
FIG. 2 is a schematic diagram of an ultrasonic device 1 to be generated. The ultrasonic device 1
A transmitting circuit 2 for transmitting an electric signal to the transducer probe 4;
Receiver circuit 6 for processing signals received by the transducer probe
And a display device 8 for generating an image of the observation target 5.
ing. Referring also to FIG. Probe 4 is a transducer element 11
Array 10. Typically, the azimuth (azimut
hal: Y) There are 128 elements 11 in the axis
A band converter array 10 is formed. However,
The transducer elements 11 in the array can each have any desired
Any number of transducer elements 11 arranged in a geometric form
It can be made up of Transducer array 10 is on the back
It is supported by a backing block 13. Probe 4
Can be hand-held and direct the ultrasound beam to the area of interest.
Position can be adjusted as needed. Transducer element 11
Converts the electric signal supplied from the transmission circuit 2 into a pressure wave
I do. The transducer element 11 also reflected from the observed object
Convert pressure waves into corresponding electrical signals. These telecommunications
The signal is processed in the receiving circuit 6 and finally the display device 8
Displayed above. FIGS. 2, 4 and 6 show a first embodiment of the present invention.
Is shown. The transducer element 11 comprises a front part 12 and a rear part 14.
And a central portion 19 and two side portions 16 and 18.
are doing. The front part 12 is located toward the inspection area.
Surface. The rear part 14 can be of the desired shape
However, it is generally flat. The front part 12 is non-planar
You. The thickness of the element 11 along the distance axis is
The thickness at 18 is large, the thickness between the two sides
Is getting smaller. The side parts 16 and 18 referred to here
Is not only the side 15 of each element 11 but also the elements
If the thickness is greater than the inner thickness of the element (for example,
(When the thickness of each side of the element is tapered)
It shall include the internal area. The front part 12 is a continuous bay
Although shown as a curved surface, the thickness of the element
Large at minutes 16 and 18, towards the central part 19
The negatively “curved” front portion 12
The front part 12 is stepped, a series of linear
Or any other form
I can't. The rear portion 14, which is preferably planar, also
It may be concave or convex. Element 11 is measured along the distance (Z) axis.
Have a maximum thickness LMAX and a minimum thickness LMIN.
are doing. Both sides 16 and 18 have LMAX thickness
Equal, at or substantially near the center of element 11
Preferably, the thickness is LMIN. But
In order to realize the present invention, each side portion 16 and 18 must be the same.
It is necessary to have one thickness, and LMIN
There is no need to be at the exact center of the element. First preferred implementation
In the example, the value of LMAX is less than 140% of the value of LMIN.
Same or equal. This generally results in ultrasound
To reprogram the ultrasound device to generate the beam
No need for bandwidth activation energy (bandwidthactiv
ation energy) can be increased. Furthermore, L
MAX value may be less than 140% of LMIN value
Or equal, the output beam for different excitation frequencies
The system width becomes the same. Bandwidth activation of the converter configuration of the present invention
The increase in energy is due to the free resonance type
(Ie, without a matching layer) or light
A chemically matched transducer (ie, at least two
(With matching layer)
Therefore, it is approximated. The first preference shown in FIGS.
In a preferred embodiment, the thickness of LMAX relative to LMIN is 4
0% (for example, LMAX is increased by 140% of LMIN).
  %) To increase the bandwidth by 40%.
Can be made. For example, if the transducer is a 0.3048 mm LM
With AX and LMIN of 0.254 mm, 0.25
The bandwidth is 2 compared to a transducer with a uniform thickness of 4 mm.
Increase by 0%. Similarly, if the transducer is 0.3556 mm
LMAX and 0.254 mm LMIN
For example, compared to a transducer with a uniform thickness of 0.254 mm,
Bandwidth increases by 40%. In this embodiment, the distance axis
The variation of the thickness of the element along can be up to 20-40%
(Ie maximum thickness is greater than 120% of minimum thickness
Equal or equal, or 140% of minimum thickness
Less than or equal to)
This broadens the bandwidth and shortens the pulse width.
This increases the maximum bandwidth by about 20-40% each.
Add. In addition, this improves resolution along the distance axis
Is done. Front part 12 with respect to rear part 14 of the first embodiment
If you change the thickness slightly, for example, operate the converter at three frequencies
Three different frequencies known as modes (eg, 2M
Hz, 2.5 MHz, and 3 MHz)
In addition, better converter performance can be obtained. This
3 frequency operation mode should be used for cardiac applications
Can be. In addition, due to slight changes in the thickness of the transducer,
Other 3 like 2.5 MHz, 3.5 MHz, and 5 MHz
Improving transducer performance even in frequency mode of operation
Is possible. The element 11 has a plano-concave structure and is made of zirconium titanate.
It is preferred to be composed of a lead acid piezoelectric material (PZT)
No. However, as described below, the element 11 is
Livinylidene (PVDF) or other suitable material
Such a composite material can also be used. See also FIG.
You. To excite element 11 to generate the desired beam
In a known manner, the electrodes 23 and 25 are connected to the front of the element 11.
It can be suitably located on the minute 12 and the rear part 14.
The electrode 25 can be arranged directly on the piezoelectric element 11, or
Alternatively, it may be located on matching layer 24. Place of the latter
In this case, it is necessary to arrange the matching layer 24 directly on the piezoelectric element 11.
Become. Electrodes 23 and 25 generate desired ultrasonic beam
An electric field through element 11 is established to cause Piezoelectric material
An example of the arrangement of the electrodes with respect to Hamada dated October 9, 1986
No. 4,611,141. First
Electrodes 23 supply signals to excite each transducer element
The second electrode 25 is grounded. Each transformation
To excite each first electrode 23 on the
The second electrode 25 (FIG. 4) can be used.
Can all be connected to electrical ground. In the field
As is known, using sputtering technology
Electrodes can be arranged on the piezoelectric layer. Alternatively,
Each transducer element using the interconnect circuit described below
Can be electrically excited. FIGS. 3 and 5 show a second preferred embodiment of the present invention.
FIG. 7 shows an embodiment, in which the same parts as those in the first embodiment are used.
The same reference numerals are given to them. In the first embodiment
6 and 8, the two embodiments are similar.
Therefore, these figures correspond to the second preferred embodiment.
Also use. Furthermore, at least a first point on the front part 12
At at least the second point on the front part
Smaller than thickness. The front part is non-planar. Second good
In a preferred embodiment, the value of LMAX is 140 of the value of LMIN.
  Greater than%. LMAX value is 140 of LMIN value
%, The resulting output beam width is typically
Typically, it changes with frequency. Furthermore, the frequency becomes lower
As the width of the output beam increases, the width of the output beam increases. FIG. 9 shows a second embodiment.
Along the height (X) direction generated by the broadband converter
Typical of beam width or aperture low frequency to high frequency
Changes. High frequency like 7MHz
In some cases, the beam has a narrow aperture. Lower frequency
Then, the beam aperture spreads. 2MHz
At a sufficiently low frequency such that the beam
Effectively generated from the entire opening. As shown in FIG.
The output pressure wave at low frequency has two peaks,
Approaches the excitation of an aperture two-dimensional transducer array. FIG. 5 relates to the second preferred embodiment.
Variation of the beam width of a full transducer array as a function of frequency
Is also shown. At higher excitation frequencies the output beam width is
With a narrow aperture, the beam is generated from the center of element 11
ing. In contrast, at lower excitation frequencies, the output beam
The beam width is wide and the beam is
Generated from By controlling the excitation frequency,
Which section of the exchanger element 11 is to generate the ultrasonic beam
Can be controlled. That is, at higher excitation frequencies
The beam is mainly generated from the center of the transducer element 11,
At lower excitation frequencies the beam is mainly
Generated from the entire aperture. Furthermore, the curvature of the front part 12
The larger, the closer element 11 is to the wide aperture two-dimensional transducer array.
It becomes so bad. Pursuing the purpose of the second preferred embodiment
In order to increase the bandwidth by more than 40%,
Ultrasonic device to excite at such a wide range of frequencies
May need to be reprogrammed. Formula LMA
As can be seen from X / LMIN, the larger the change in thickness,
The spread of the bandwidth increases. According to the principles of the present invention,
300% or more bandwidth for a given design
Increase can be achieved. That is, the thickness LMAX
Is almost three times larger than the thickness LMIN. For example
Increase the bandwidth of a single transducer element from 2 MHz to 11 MHz
Although it can be extended to a range, according to the principles of the present invention
Even wider ranges can be achieved. According to the invention
Transducer arrays manufactured with such a wide range of frequencies
It is possible to operate on numbers (ie the converter is
Operable at the main fundamental harmonic frequency and the main second harmonic
Frequency)), the fundamental and second harmonic
The harmonic contrast imaging method for observing both is a single transformation according to the present invention.
This can be achieved using a heat exchanger array. As shown in FIGS. 10 and 11, the transducer element
Varying the thickness of 11 significantly increases the bandwidth. Figure
10 and 11 are when the plano-concave transducer element 11 is used.
Here is an example of the effect on bandwidth and the results are specific to
It can vary depending on the form. FIG. 10 shows a second embodiment of the present invention.
For the transducer element 11 manufactured according to the preferred embodiment
The plotted impedance is shown. This converter
The thickness of the side portion of element 11 is 0.015 inch (0.381 m
m) with a center thickness of 0.00428 inches (0.109 m
m). As is evident from the figure, the element is about 3.5 MH
It has a bandwidth from z to 10.7 MHz. to this
On the other hand, as shown in FIG. 11, a uniform thickness of 0.381 mm
Common elements with a typical value of about 4.5 MHz to 6.6
  Bandwidth up to MHz. That is, the anti-resonance frequency (immediately
(Maximum impedance) faAnd the resonance frequency (ie,
Minimum impedance) frAnd compare Δf
Allows prior art designs to have approximately 38% partial bandwidth
(fractal bandwidth), whereas the present invention
Therefore, the manufactured transducer element has 100% partial bandwidth.
You can see that it is provided. Therefore, the bay of the transducer element
The shape of the song (ie cylindrical, parabolic, Gaussian,
Or stepped, even triangular
Control) of the energy emitted
The frequency content can be effectively controlled. these
Use of each shape, as well as other shapes, is within the scope of the invention.
To be understood. The same components are given the same reference numbers.
The transducer structure manufactured according to the invention shown in certain FIGS.
The structure is curved on the front part 12 of the transducer element 11
The matching layer 24 is provided. Matching layer 24 is filled
Preferably made in Lima. Further, the thickness of the matching layer 24
Reduces the LML at a given point on the transducer surface to the matching layer
Thickness, LE is the thickness of the transducer element, CML is matched
The sound velocity in the stratum, and CE as the sound velocity in the element, the equation LML = (1/2) (LE) (CML / CE) Is preferably approximated by The thickness of the matching layer 24 is
Depends on the thickness of the element at a given point on the transducer surface
From the curvature of the front portion 12 is the top portion 26 of the matching layer 24
It can be different from the song. Using the above formula, 1
Or it is preferable to form more matching layers
However, due to the ease of manufacturing, the matching layer
I don't support it. By adding the matching layer 24,
The bandwidth can be improved. Further increase the sensitivity of the transducer
Can be added. However, the assembled base
The difference in thickness between the edge and the center of the material provides the desired increase in bandwidth.
Control and the shape of the curvature is the fundamental band in the frequency domain
Control the shape. Furthermore, both the transducer element 11 and the matching layer 24
Since both have a negative curvature, additional
Focusing is obtained. Focusing and transforming the ultrasound beam to the area of interest
In order to improve the sensitivity of the device, one or more matching layers
2 can be added. Preferably, the piezoelectric element or
Two matching layers are arranged on the transducer element 11 and are optically aligned.
A combined transducer is formed. Each matching layer has the formula LML =
Calculated by (1/2) (LE) (CML / CE)
You. More specifically, the thickness LML of the first matching layer is calculated.
In that case, the value of the sound velocity CML of the first material is used. No.
When calculating the thickness LML of the second matching layer, the second material
The value of the sound speed CML of the material is used. Preferably, the first alignment
The acoustic impedance of the composite layer (ie, the matching layer closer to the piezoelectric element)
-The value of the dance is about 10 Mega Rails (Mega Rayls),
Of the second matching layer (that is, the matching layer closer to the object to be observed)
The value of the acoustic impedance is about 3 megarail. Examination
The coupling element 27 having the acoustic characteristic to be inspected is placed on the matching layer,
Or, for example, if no matching layer is used, the second
It can be arranged directly on the electrode 25. Coupling element 27
Are any sharp points on the transducer structure that come into contact with the body under inspection.
Comfortable for the patient because it can relieve rough surfaces
Give a feeling. The coupling element 27 is, for example, a front part 12 or
Can be used for applications where the top section 26 has a large bend.
Can be. The coupling element 27 is made of unfilled polyurethane.
It can be formed of tongue. The connecting element as a whole
Has a flat, slightly concave or slightly convex surface 29
can do. Preferably slightly curved surface 29
As a concave, a new jaw between the probe 4 and the object to be inspected
Aquasonic from Parker Labs in Orange, Georgia
(Ultrasonic Gel 28)
To This is a strong sound between the probe 4 and the test object.
Give sound contact. The matching layers and tie layers described above
It can be arranged in all the embodiments. In the ultrasonic industry
Machines like widely used numerical control machine tools
Can be used to vary the thickness of the transducer element.
Wear. Machine tools are available for LMAX and LMIN
The initial piezoelectric layer can be processed to give a thickness change.
Wear. FIG. 16 shows a piezoelectric layer 8 when the front portion is to be curved.
0 shows a first method of processing 0. h is LMAX and LMI
The difference in thickness from N, w along the height (elevation) axis
First, the expression h / 2 + (wTwo/ 8h)
The coordinates that define the radius of curvature R approximated by
Input to your machine. Numerical control machine has the same dimensions as piezoelectric layer 80
The piezoelectric layer is processed by a grinding wheel 84 having a width of
You. The grinding wheel 84 is centered on an axis 86 parallel to the height axis.
And rotate. The grinding wheel 84 is made of aluminum oxide.
Contains such grinding materials. The grinding wheel 84 is a piezoelectric
Processing starts at one end of the layer 80 and ends at the other end of the piezoelectric layer.
It is preferable to machine along the azimuth direction until
Good. FIG. 17 shows an alternative method of processing the piezoelectric layer 80.
Is shown. In this method, the grinding wheel 84 has one corner
88 is inclined so as to contact the surface of the piezoelectric layer 80.
You. In a given orientation region, the grinding wheel 84 is
Starting grinding from one side along the height axis of 80, the piezoelectric layer
Continue grinding until reaching the other side along the 80 height axis
(For example, a grinding wheel has a certain index in the azimuth axis.
And the desired grinding along the height axis). Laboratory
The grinding wheel 84 rotates about an axis 90. Next,
Grinding wheel 84 reaches the next area or index along the azimuth axis
Move to the height axis from one side of the piezoelectric layer to the other
Repeat the processing along. This process covers the entire piezoelectric layer 80
Is repeated until the desired curvature 82 is obtained.
You. The machined surface should be smooth
It can be ground or polished. Transducer at 20 MH
For very high frequencies such as z
Is particularly desirable. See also FIGS. 7 and 18
You. As is well known, dice cuts are made in the piezoelectric material.
And a plurality of electrically independent
The formed piezoelectric element 11 is formed. Multiple cuts 94
Of the matching layer 24, the piezoelectric element 11, and the electrode 23 are obtained.
You. To ensure electrical insulation between the transducer elements,
The mouth 94 can be slightly extended into the backing block 13.
Wear. Referring to FIG. Pressure before making a cut
A metallization layer is deposited directly on top of the electrical
Can also be formed. Since the matching layer 24 is also used,
If present, the second electrode 25 is on the top portion 26 of the matching layer 24
It is preferable to arrange them. However, the matching layer 24
Top section 26 should be metallized across the edge of the matching layer
Or magnesium or conductive epoxy
By using such a conductive material, the second electrode
Is preferably short-circuited. In addition, use matching layers
If not, cut the matching layer after placing it on top of the piezoelectric layer.
Just put in. In a preferred embodiment, the second electrode is grounded.
Be kept in place. If you use the flexible circuit 96 described below
If so, make a cut through this flexible circuit and
Is formed. Converter in sector format
Along the azimuth direction when designed to operate on
The length S, the distance between the elements, is the maximum operating frequency of the transducer
Approximation to the half-wavelength within the object under inspection
New This approximation also applies to the two-crystal design described below.
You. When designing the converter to operate linearly,
Or if the shape of the transducer array is curved,
The value S is the value within the test object at the highest operating frequency of the transducer.
It can be varied between one wavelength and two wavelengths. FIG. 19 is manufactured in accordance with the principles of the present invention.
2 shows a curved transducer array. In detail, a curved array
A is manufactured similarly to the linear converter array of FIG. I
However, as shown in FIG.
Not directly on the block 13
The element 11, the flexible circuit 96 and the corresponding electrode 23 are about 1 mm thick.
Directly on the first backing block 13 '
Have been. This allows the array to be expanded to expand the field of view
It can be easily bent by a desired amount. Typically
Means that the radius of curvature of the first backing block 13 'is about 44 m
m, but can be changed as needed. First
The backing block 13 'has a thickness of about 2 cm in the distance direction.
Use epoxy glue for the second backing block 13 "having
Can be glued. First backing block 1
The surface of the second backing block 13 "in contact with 3 'is the same
It is preferable to have a radius of curvature of In the field
As is well known, curved arrays are in front of linear arrays.
Same as linear array with placed mechanical lens
To work. The signal at the central part 19 of the transducer element 11
No. is stronger than at end or side portions 16 and 18
Therefore, accurate apodization occurs (ie,
Side lobe generation is reduced or suppressed). this is,
The electric field between the two electrodes on the front part 12 and the rear part 14 is centered
Maximum on section 19, reducing sidelobe generation
Is caused by Furthermore, the front and rear parts are flat.
Since it is not a flat parallel surface, the field between the transducer and the object to be inspected is
Undesired reflections on surfaces (ie, ghost echoes)
Is well suppressed. Still further, it is manufactured according to the present invention.
Transducer arrays can operate over a wide range of frequencies
The transmitter must be able to operate at frequencies other than the transmitted center frequency.
It is possible to receive a signal at the center frequency. The design of the distance between the elements 11 and the transducer aperture
Or, when it comes to the design of width w, the upper limit
The working frequency is the highest in the grating lobe.
A great influence. Consider the maximum operating frequency of the transducer
By designing the distance between the elements, the grating lobe
Image artifacts or artifacts (ie,
Generation of unwanted multiple mirror images of the object to be measured)
it can. Specifically, the grating lobe angle Θg,
Electronic steering angle in Kuta formatsOf the converter
The wavelength λ within the test object at the highest operating frequency and the required
The relationship between the prime distances S is given by: S ≦ λ / (sinΘs− SinΘg) Thus, for a given grating lobe angle, the transformation
The aperture design is limited by the upper operating frequency of the transducer
It is. As can be seen from the above equation, sweep at a higher frequency
In order to achieve this, it is necessary to narrow the aperture correlated to that frequency.
is there. For example, at an operating frequency of 3.5 MHz,
The desired distance S between the elements is 220 μm,
The distance S is 110 μm. At higher frequencies
Reduces the aperture of the transducer element given by the above equation.
Use the transducer element at a lower frequency.
If used, the resolution will be lost. This is low
Operation at higher frequencies typically results in larger element apertures
Is required. However, this
LMAX value greater than 140% of LMIN value
And obtained by a wider aperture at lower frequencies
If the resolution of the image is increased, the
By the fact that it simulates a two-dimensional array in numbers
Compensated. A two crystal transducer element using the principles of the present invention
Can be designed. Dual crystal converter shown in FIG.
Element 40 comprises a first piezoelectric portion 42 and a second piezoelectric portion 44
And These piezoelectric parts are two separate pieces
It may be processed as. Preferably, both surfaces 46 and 48
Is given by the formula h / 2 + (wTwo/ 8h). However
Where h is the thickness difference between LMAX and LMIN, w is
The width of the transducer element along the height axis. Piezoelectric part 42 and
Although the structure of 44 is shown as being plano-concave, the surface 4
6 and 48 are stepped configurations, a series of linear segments, if
Or other forms. Each part 42 and 44
Is large in the side portions 43, 45, 47 and 49
In each case, it is smaller at each central part. Change
The rear portions 51 and of the piezoelectric portions 42 and 44 respectively
53 is preferably a plane. However, this
These surfaces can also be non-linear. First piezoelectric part
Interconnect circuit 50 between the first and second piezoelectric portions 44
Is arranged. The interconnect circuit 50 may be acoustic or
Any interconnections used in the field of integrated circuits
It may consist of a continuation design. Typically, the interconnect times
Path 50 carries leads for exciting transducer element 40
It is made of a layer of copper. The copper layer is typically
It can be glued to a piece of polyamide material that is Kapton
Wear. The copper layer is coextensive with each piezoelectric part 42 and 44
Preferably, it is a dimension. In addition, the interconnect circuit
Gold plating can be used to improve tactile performance. This
An interconnect circuit like Northfield, Minnesota
 It may be a flexible circuit manufactured by Sheldahl. To further improve the performance, the matching layer 52
Can be arranged on the piezoelectric part 42. 1st and 1st
When both piezoelectric parts are made of the same material
Calculates the LML at a given point on the transducer surface as the thickness of the matching layer.
And LE is the thickness of the first and second piezoelectric portions, and C
Let ML be the speed of sound in the matching layer and CE be the
As the sound velocity, the thickness LML of the matching layer 52 is (1/2) (L
E) approximated by (CML / CE). Electrode or contact
The formations 58 and 59 are applied directly on the matching layer 52 and on the surface 48
Can be arranged to connect two piezoelectric parts in parallel
You. The matching layer 52 is made of a conductive material such as nickel and gold.
Can be coated. However, if a matching layer is used,
If not used, both ground layers are both
And directly on the base 44. The matching layer 52 corresponds to the inspection area.
Face. The transducer 40 is used in the ultrasonic field.
In general, it is arranged on the backing block 54 as is common.
Can be placed. Furthermore, the coupling element as described above also
Can be used. FIG. 13 uses the principle of the present invention.
Another two crystal design 55 is shown. First piezoelectric portion 56 and
And a second piezoelectric portion 57. Piezoelectric part 56
Is preferably plano-concave. Furthermore, the second piezoelectric
The portion 57 has a thickness that varies along the height direction.
You. The interconnection circuit 50 as described above is connected to two piezoelectric parts.
Can be used to excite double crystal transducer 55
You. The matching layer and coupling element as described above are also provided to improve performance.
Improve patient comfort. In addition, an electrode or ground layer 58
Connecting two piezoelectric parts in parallel using
Can be. The rear part 61 of the first piezoelectric part 56 is flat.
Preferably, there is. Front portion 63 of first piezoelectric portion 56
And the radius of curvature R of the rear portion 65 of the second piezoelectric portion 57 is
h is the difference between the thickness of LMAX and LMIN of the piezoelectric portion 56.
And where w is the width of the transducer element along the height axis, the equation h / 2
+ (WTwo/ 8h). LMAX and L
The value of MIN is for the first and second piezoelectric portions 56 and 57.
And it is preferably the same. Of the second piezoelectric portion 57
The radius of curvature R of the front portion 67 is obtained by combining h 'with the combination of the two piezoelectric portions.
The difference between the combined maximum thickness and the minimum combined thickness, w
The width of the transducer element along the axis is expressed by the formula h '/ 2 + (wTwo
/ 8h ′). Get the desired radius of curvature
Therefore, the piezoelectric portions 56 and 57 are numerically controlled as described above.
It can be processed by your machine. Uniform piezoelectric material
Instead of using layers, a composite structure as shown in FIG.
60 can be used to form a composite material. composite
The structure 60 comprises a plurality of piezoelectric materials having various thicknesses.
Includes columns 62 or slabs. Between the columns 62, for example
There is a polymer layer 64 which may be formed of an epoxy material.
You. For composite materials, see Materials Research Bu
lletin, Vol. 13 (1978), pages 525-536.
Newham et al., “Connectivity and Piezoelectric-P
yroelectric Composites "and Materials Research
 R. Bulletin, Vol. 13 (1978), pages 599-607.
 E. Newham et al., “Flexible Composite Transduce
rs ". Composite structure 60 must be plano-concave
Is preferred. Acoustic matching layer (shown to improve performance)
(Not shown) on the front portion 66. The composite material can be embedded in a polymer layer.
Wear. The composite is then ground to the desired dimensions and processed.
Can be engineered or formed. In addition, ultrasonic
In the field, this composite structure is
Notching the structure to form individual transducer elements
Can be. Fill the gap between each transducer element with polymer material
Thus, electrical insulation between elements can be ensured. Front part
66 is shown as a curved surface, the front portion 66
Is a stepped form, a series of linear segments, or something
Other forms can be adopted. The thickness of the structure 60 is
Large at side parts 70 and 72, small at center
It's getting worse. Further, the rear portion 68 is illustrated as a plane.
But the rear part is flat, concave, or convex.
May be. Combine electrodes 74 and 76 similar to the electrodes described above
It can be located on the front and back parts of the structure. Figure
The composite structure 60 of FIG. 14 is deformed as shown in FIG.
A concave portion 66 'and a concave portion 68' can be obtained. Figure
The deformed structure of FIG. 15 is obtained by mechanically deforming the structure of FIG.
Let's get it. In some applications, before deformation
14 can be heated. If vertical pillar 6
The filling material between the two is made of silicon instead of epoxy material
If it is, the structure of FIG. 14 can be easily applied without applying heat.
Can be deformed. If epoxy material is used
If so, the structure of FIG.
Should be exposed to 0 ° C. heat. Furthermore, the composite structure is
66 'and the convex portion 68' in the opposite direction to obtain
It can also be deformed (not shown). FIG.
By forming a converter structure, only a broadband converter can be obtained.
But generally focus the ultrasound beam on the region of interest
It becomes possible. The structure was modified as shown in FIG.
By adjusting the focusing of the ultrasonic beam,
It becomes possible to do. To operate, the transducer array 10 is first
Activate at higher frequencies along a given scan direction,
Focus the wave beam at one point in the near field (or field)
Let it. The transducer gradually moves along a series of points along the scan line.
And as the beam is gradually focused to a far field
To reduce the excitation frequency. LMAX value is LMIN
If it is greater than 140% of the value,
The output beam width having a large aperture as shown in FIG.
The aperture widens as the excitation frequency decreases. Final
At a sufficiently low frequency, such as 2 MHz
10 uses the entire aperture of the transducer element 11 to
Approaches a two-dimensional array by producing effectively.
Further, the greater the curvature of the front portion 12, the more the transducer 10
Get closer to a two-dimensional array. Further bandwidth and sensitivity performance
To increase, the matching layer 24 is added to the front part 12 of the element 11.
It can also be placed on top. In addition, harmonic contrast imaging was performed.
The transducer array element 11 is first switched to 3.5 MHz
Excited at the primary fundamental harmonic frequency, such as the heart or other
Observe the observed tissue. Then the transducer array element 11
 Set the main second harmonic reception mode such as 7.0 MHz
And the contrast material is more clearly visible to the tissue
To do. This will show how well your organization works
Can be confirmed. When observing fundamental harmonics
In addition, a filter centered on the fundamental frequency (for example,
Expression filter) can be used. The second harmonic
When observing, the frequency centered on the second harmonic frequency
Filters can be used. Converter as described above
The array can be set to the second harmonic reception mode
However, the transducer array transmits and receives at the second harmonic frequency.
can do. A pulse is applied to obtain a desired excitation frequency.
Adding is known. Impulse illustrated in FIG.
Response 100 has a width of about 0.25 μs. This Inn
The pulse response 100 is LMIN 0.109 mm, LMA
X is 0.381 mm, and the radius of curvature of the front part 12 is 10
Response of a 3.54 mm transducer to impulse excitation
It is. This impulse response 100 is about 1 MHz to 9
Yields a frequency spectrum in the MHz range. Far away
Converted for viewing or generating an ultrasonic beam
So that there is no restriction on choosing a given opening of the vessel element 11
In some applications, the transducer element 11 may be implemented using impulse excitation.
It is desirable to excite The full aperture of the transducer element 11
Excitation increases the resolution along the distance axis.
It will also help. When looking at the near field,
In order to select the opening of the central part 19, about two to five
Transducer element 11 using a series of pulses, such as pulses
Can be excited. The frequency of these pulses is required
Correlate with the central part 19 of the element 11. Typically this
The frequency of these pulses is about 7 MHz, and the pulse width is
It is about 0.14 μs. As described above, the two-dimensional
To get closer to the ray, it takes about 2 to 5 pulses
Exciting the transducer element 11 by applying a series of simple pulses
Can be. The frequency of these pulses is
Resonant frequency correlated to the thickest or side portions 16, 18
Match the number. Typically, the frequency of these pulses
Is about 2.5 MHz and the pulse width is about 0.40 μs
is there. This produces sharp images when looking at distant fields.
To help. Single crystal design shown in FIGS. 3, 5 and 18
Elements 11 are 15 mm in height and azimuth
0.0836 mm. The distance S between the elements is 0.109 mm
The length of the cut is 25.4 μm. Thickness LMIN
Is 0.109 mm and the thickness LMAX is 0.381 mm
is there. The radius of curvature of the front part 12 is 103.54 mm. back
The abutment block is Dow Corning part number DER 3
32 is treated with the company's curing agent DEH 24, and aluminum oxide
Formed of a filled epoxy with a lithium filler
You. Backing block for 128-element transducer array
The dimensions of the rack are 20 mm in the azimuth direction and 16 m in the height direction
m, and 20 mm in the distance direction. Shape of matching layer 24
The shape and dimensions are the LML at a given point on the transducer surface
Is the thickness of the matching layer, LE is the thickness of the transducer element, and CML is the
The velocity of sound in the layer and CE as the velocity of sound in the element
ML = close by (1/2) (LE) (CML / CE)
Let them resemble. Transducer has acoustic response technology (ART) capability
Like Acuson Corporation's 128 XP system
It can be used with any commercially available unit. In the two-crystal design shown in FIG.
Thickness measured in the distance direction between the two piezoelectric portions 42 and 44
Is 0.127 mm and the maximum thickness is 0.2794 mm.
You. Half the curvature of the surfaces 46 and 48 of the piezoelectric parts 42 and 44
The diameter is 184.62 mm. The distance S between the elements is 0.254 m
m and the cut length is 25.4 μm. In FIG.
In the case of the two crystal design shown, the top of the piezoelectric portions 56 and 57
Small thickness is 0.127mm, maximum thickness is 0.2794mm
It is. The front portion 63 of the first piezoelectric portion 56 and the second pressure
The radius of curvature of the rear portion 65 of the electric portion 57 is 184.62 mm.
You. The radius of curvature of the front portion 67 of the piezoelectric portion 57 is 92.426 m
m. Finally, the composite structure design shown in FIG.
Or it is preferable to set the same size as the size of 5,
This forms 128 transducer elements. The configuration of FIG.
The construction also has a flat rear portion 68, which is
This is particularly desirable when focusing. The configuration of FIG.
The structure is to deform both ends of the structure of Fig. 14 in the distance direction
Can be formed by About 2c inside the inspected body
When focusing on a field near m, the side of the structure of FIG.
Should be deformed by about 0.25 mm with respect to the central part
It is. Backing block, flexible circuit, piezoelectric layer, matching
The layers and the tie layers each use some epoxy material.
Can be glued together. California
 Hys from Dexter Corp., Hysol Division of Industry
ol® curing agent # HD3561 and Hysol
# 2039, the base material, is a variety of materials
Can be used for gluing. Typically
The thickness of the epoxy material is about 2 μm. First electrode
The thickness of the flex circuit to form the appropriate electrical excitation
Is about 25 μm for a Sheldahl flexible circuit.
You. The thickness of the second electrode is typically between 2000 and 3000
Angstroms and uses sputtering technology
Can be deposited on the transducer structure by
You. The transducer array manufactured according to the present invention is
 Operable at 3rd harmonic such as 10.5 MHz
Note that it is noh. This is even more
To provide information. Furthermore, adding the matching layer 24
Thus, the transducer array can be used over a wider range of frequencies.
Even can work. Therefore, this is also the present invention.
Of the two fundamental harmonics and the second harmonic
Make it possible to work on The shape of the present invention described above is preferable.
This is merely an example, and the idea or features of the present invention are
Its shape, dimensions and dimensions without departing from the scope of the appended claims.
And various arrangements of parts and components
No.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of an ultrasonic beam device for generating an image. FIG. 2 is a cross-sectional view of the transducer element according to the first preferred embodiment; FIG. 3 is a sectional view of a transducer element according to a second preferred embodiment; FIG. 4 is a perspective view of a broadband transducer array which is a first preferred embodiment of the probe of FIG. 1; 5 is a perspective view of a wideband transducer array, which is a second preferred embodiment of the probe of FIG. 1, and also shows the beam width at low and high frequencies. FIG. 6 is an enlarged view of a single transducer element in a transducer array according to the present invention. FIG. 7 is a perspective view of a broadband transducer array having a curved matching layer disposed on a front portion of the transducer element and used as the probe of FIG. 1; FIG. 8 is a cross-sectional view of a single broadband transducer element having a curved matching layer and a coupling element. FIG. 9 illustrates how the output beam width generated by the wideband converter element according to the second embodiment of the present invention varies with frequency. FIG. 10 is an example of a typical acoustic impedance frequency response plot obtained by operation of a transducer according to a second embodiment of the present invention. FIG. 11 is an example of a typical acoustic impedance frequency response plot obtained by operation of a conventional transducer. FIG. 12 is a cross-sectional view of a double crystal transducer structure according to a third embodiment of the present invention, showing that there is an interconnect circuit between two crystal elements. FIG. 13 is a cross-sectional view of an alternative two crystal transducer structure. FIG. 14 is a sectional view of a composite converter element according to a fourth embodiment of the present invention. FIG. 15 is a cross-sectional view of the composite transducer element of FIG. 14 after being deformed. FIG. 16 is a cross-sectional view showing a piezoelectric layer and a grinding wheel for explaining a preferable method of processing the surface of the piezoelectric layer. FIG. 17 is a cross-sectional view showing a piezoelectric layer and a grinding wheel for explaining another preferable method of processing the surface of the piezoelectric layer. FIG. 18 is a partial perspective view of a linear transducer array according to the present invention. FIG. 19 is a partial perspective view of a curve converter array according to the present invention, with one end of the flex circuit removed for clarity. FIG. 20 shows the impulse response of the transducer element of FIG. 6 and the corresponding frequency spectrum. [Description of Signs] 1 Ultrasonic device 2 Transmitting circuit 4 Transducer probe 5 Observation target (body) 6 Receiving circuit 8 Display device 10 Array 11 Transducer element 12 Front part 13 Backing block 14 Rear part 15 Side 16 Side part 17 Lead 18 Side part 19 Center part 23 Electrode 24 Matching layer 25 Electrode 26 Matching layer top part 27 Bonding element 28 Ultrasonic gel 29 Bonding element surface 40 2 Crystal transducer element 42 First piezoelectric part 43, 45 First Side portion 44 of the piezoelectric portion of the second portion 46 of the first piezoelectric portion 47, surface portion 49 of the first piezoelectric portion 48 side portion 48 of the second piezoelectric portion surface 50 of the second piezoelectric portion interconnecting circuit 51 of the first piezoelectric portion Back part 52 Matching layer 53 Back part of second piezoelectric part 54 Backing block 55 2 Crystal transducer element 56 First piezoelectric part 57 Second piezoelectric part 58, 59 Electrode (ground layer) 60 Composite structure 61 Back portion of first piezoelectric portion 62 Column of piezoelectric material 63 Front portion of first piezoelectric portion 64 Polymer layer 65 Back portion 66 of second piezoelectric portion Front portion 67 Front portion of second piezoelectric portion 68 Rear part 70, 72 Side part 74, 76 Electrode 80 Piezoelectric layer 82 Curve 84 Grinding wheel 86, 90 Grinding wheel shaft 88 Grinding wheel corner 94 Cutout 96 Flexible circuit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. 7 Identification code FI G01S 7/02 G01S 7/02 F H01L 41/09 H04R 31/00 330 H04R 31/00 330 H01L 41/08 C J (72) Inventor Jay S. Pluge 94040 Mountin View Chem Bridge Lane, California, United States 3566 (56) References JP-A-64-6754 (JP, A) JP-A-1-81100 (JP, U) (58) Fields studied (Int .Cl. 7 , DB name) H04R 17/00 330 A61B 8/00 G01N 29/24 G01S 7/02 H01L 41/09 H04R 31/00 330 H04R 17/00 332

Claims (1)

  1. (57) Claims 1. A two-crystal converter having a piezoelectric layer along a region direction, wherein a thickness at at least one point of a surface facing a region to be inspected is at least one of the surfaces. A first piezoelectric layer having a thickness smaller than that of another point and having a non-planar surface, a second piezoelectric layer, and a first piezoelectric layer disposed between the first piezoelectric layer and the second piezoelectric layer; A two-crystal converter, comprising: an interconnect circuit; 2. An array-type ultrasonic transducer, comprising: a plurality of transducer elements arranged adjacent to each other, each of said elements being a front portion facing a region to be inspected, a rear portion, Comprising two side portions and a thickness between the front portion and the rear portion, wherein the thickness of the transducer is a maximum thickness at the side portions and a minimum thickness between the side portions. The maximum thickness is 140% or less of the minimum thickness. 3. A method of manufacturing a transducer, comprising: a front portion facing a region to be inspected, a rear portion, two side portions, and a thickness between the front portion and the rear portion. Wherein the thickness at at least one point on the front portion is at least one other on the front portion.
    Forming a piezoelectric element that is smaller than the thickness at two points and symmetric about a central axis thereof; and deforming the piezoelectric element. 4. A transducer for generating an ultrasonic beam by excitation, comprising: a piezoelectric element comprising a composite material, wherein the piezoelectric element is symmetrical about a central axis thereof, and wherein the element is an area to be inspected. A front portion, a rear portion, and a thickness between the front portion and the rear portion, wherein the thickness at at least one point on the front portion is at least one point on the front portion. A transducer, wherein the thickness is less than the thickness at another point, the front portion and the rear portion being curved. 5. An ultrasonic change array for inspecting a body, comprising: a plurality of transducer elements arranged along an array axis; and a backing support for supporting the plurality of transducer elements. Each of the plurality of transducer elements of the array has a front surface covered by a front electrode and a back surface covered by a rear electrode, the front surface being concave along an axis perpendicular to the array axis. , Having a non-uniform thickness, the thickness
    A piezoelectric layer having a minimum near the center of the layer and a maximum at each end of the layer, wherein the thickness continuously increases from a minimum thickness to a maximum thickness; and A first acoustic matching layer having a concave front surface, a rear surface, and a uniform thickness along the back surface attached to the concave front surface of the piezoelectric layer; and Each of the plurality of transducer elements has its piezoelectric layer and at least a portion of its first acoustic matching layer spaced from adjacent transducer elements of the array; An ultrasonic transducer array, wherein the concave shape of the front surface of the acoustic matching layer is selected to mechanically focus the transducer element in a plane perpendicular to the array axis. 6. A transducer for generating an ultrasonic beam by excitation, comprising: a plurality of piezoelectric elements, each of said piezoelectric elements having a plano-concave shape, wherein said elements have a fundamental frequency exceeding the excitation frequency. A transducer for generating an acoustic beam and receiving a reflected ultrasonic beam at a harmonic frequency. 7. An ultrasonic transducer array comprising a plurality of transducer elements, each element having a plano-concave shape, and a transmission circuit connected to said transducer array and operative to transmit energy at a fundamental frequency. And a receiving circuit connected to the transducer array and operable to filter ultrasonic echo information at a fundamental frequency and simultaneously selectively receive ultrasonic echo information in the vicinity of a harmonic frequency from a target. An ultrasonic imaging system characterized in that:
JP19920094A 1993-09-07 1994-08-24 Ultrasonic phased array converter and method of manufacturing the same Expired - Lifetime JP3478874B2 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US08/117868 1993-09-07
US08/117869 1993-09-07
US08/117,868 US5415175A (en) 1993-09-07 1993-09-07 Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof
US08/117,869 US5438998A (en) 1993-09-07 1993-09-07 Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof

Publications (2)

Publication Number Publication Date
JPH07107595A JPH07107595A (en) 1995-04-21
JP3478874B2 true JP3478874B2 (en) 2003-12-15

Family

ID=26815733

Family Applications (1)

Application Number Title Priority Date Filing Date
JP19920094A Expired - Lifetime JP3478874B2 (en) 1993-09-07 1994-08-24 Ultrasonic phased array converter and method of manufacturing the same

Country Status (6)

Country Link
EP (1) EP0641606B1 (en)
JP (1) JP3478874B2 (en)
AT (1) AT189415T (en)
AU (1) AU688334B2 (en)
CA (1) CA2129946C (en)
DE (2) DE69422867T2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7728490B2 (en) 2004-06-07 2010-06-01 Olympus Corporation Capacitive micromachined ultrasonic transducer

Families Citing this family (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9610511D0 (en) * 1996-05-20 1996-07-31 Cantwell Evelyna D Scanning ultrasound probe
JP2003092796A (en) * 2001-09-18 2003-03-28 Ueda Japan Radio Co Ltd Ultrasonic wave vibrator with curved face
US6984922B1 (en) 2002-07-22 2006-01-10 Matsushita Electric Industrial Co., Ltd. Composite piezoelectric transducer and method of fabricating the same
CN100450444C (en) * 2003-01-23 2009-01-14 株式会社日立医药 Ultrasonic probe and ultrasonic diagnosing device
WO2004091812A2 (en) * 2003-04-15 2004-10-28 Koninklijke Philips Electronics N.V. Two-dimensional (2d) array capable of harmonic generation for ultrasound imaging
CN101431941B (en) * 2006-04-28 2011-05-18 松下电器产业株式会社 Ultrasonic probe
JP5157127B2 (en) * 2006-10-31 2013-03-06 セイコーエプソン株式会社 Actuator device, manufacturing method thereof, liquid jet head, and liquid jet device
GB0723622D0 (en) * 2007-12-04 2008-01-09 Univ Exeter The Devices, systems and methods of detecting defects in workpieces
US8691145B2 (en) 2009-11-16 2014-04-08 Flodesign Sonics, Inc. Ultrasound and acoustophoresis for water purification
US9783775B2 (en) 2012-03-15 2017-10-10 Flodesign Sonics, Inc. Bioreactor using acoustic standing waves
US10322949B2 (en) 2012-03-15 2019-06-18 Flodesign Sonics, Inc. Transducer and reflector configurations for an acoustophoretic device
US9745548B2 (en) 2012-03-15 2017-08-29 Flodesign Sonics, Inc. Acoustic perfusion devices
US9272234B2 (en) 2012-03-15 2016-03-01 Flodesign Sonics, Inc. Separation of multi-component fluid through ultrasonic acoustophoresis
US9752114B2 (en) 2012-03-15 2017-09-05 Flodesign Sonics, Inc Bioreactor using acoustic standing waves
US9745569B2 (en) 2013-09-13 2017-08-29 Flodesign Sonics, Inc. System for generating high concentration factors for low cell density suspensions
US9567559B2 (en) 2012-03-15 2017-02-14 Flodesign Sonics, Inc. Bioreactor using acoustic standing waves
US10370635B2 (en) 2012-03-15 2019-08-06 Flodesign Sonics, Inc. Acoustic separation of T cells
US9458450B2 (en) 2012-03-15 2016-10-04 Flodesign Sonics, Inc. Acoustophoretic separation technology using multi-dimensional standing waves
JP2014198197A (en) * 2013-03-29 2014-10-23 セイコーエプソン株式会社 Acoustic matching body, ultrasonic probe, and ultrasonic imaging device
CN103278570A (en) * 2013-06-13 2013-09-04 江苏大学 Ultrasonic linear phased array transducer for detecting metallic material and manufacturing method
US9796956B2 (en) 2013-11-06 2017-10-24 Flodesign Sonics, Inc. Multi-stage acoustophoresis device
US9744483B2 (en) 2014-07-02 2017-08-29 Flodesign Sonics, Inc. Large scale acoustic separation device
US10106770B2 (en) 2015-03-24 2018-10-23 Flodesign Sonics, Inc. Methods and apparatus for particle aggregation using acoustic standing waves
EP3319739A1 (en) * 2015-07-09 2018-05-16 Flodesign Sonics Inc. Non-planar and non-symmetrical piezolectric crystals and reflectors
US20190200959A1 (en) * 2017-12-29 2019-07-04 Fujifilm Sonosite, Inc. High frequency ultrasound transducer
WO2019236409A1 (en) * 2018-06-04 2019-12-12 Fujifilm Sonosite, Inc. Ultrasound transducer with curved transducer stack

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3666979A (en) * 1970-06-17 1972-05-30 Automation Ind Inc Focused piezoelectric transducer and method of making
US3833825A (en) * 1973-04-11 1974-09-03 Honeywell Inc Wide-band electroacoustic transducer
US4016751A (en) * 1973-09-13 1977-04-12 The Commonwealth Of Australia Care Of The Department Of Health Ultrasonic beam forming technique
DE2508023B2 (en) * 1974-02-26 1977-06-30 Broadband ultrasound transducer and its application
US4350917A (en) * 1980-06-09 1982-09-21 Riverside Research Institute Frequency-controlled scanning of ultrasonic beams
JPS624973B2 (en) * 1980-06-27 1987-02-02 Matsushita Electric Ind Co Ltd
US4398539A (en) * 1980-06-30 1983-08-16 Second Foundation Extended focus transducer system
US4485321A (en) * 1982-01-29 1984-11-27 The United States Of America As Represented By The Secretary Of The Navy Broad bandwidth composite transducers
US4534221A (en) * 1982-09-27 1985-08-13 Technicare Corporation Ultrasonic diagnostic imaging systems for varying depths of field
EP0145429B1 (en) * 1983-12-08 1992-02-26 Kabushiki Kaisha Toshiba Curvilinear array of ultrasonic transducers
DK212586A (en) * 1986-05-07 1987-11-08 Brueel & Kjaer As A process for preparing an ultrasound transducer
FR2612722B1 (en) * 1987-03-19 1989-05-26 Thomson Csf multifrequency acoustic transducer, in particular for medical imaging
US4866683A (en) * 1988-05-24 1989-09-12 Honeywell, Inc. Integrated acoustic receiver or projector
JP2502685B2 (en) * 1988-06-15 1996-05-29 松下電器産業株式会社 Method of manufacturing the ultrasonic probe
US4963782A (en) * 1988-10-03 1990-10-16 Ausonics Pty. Ltd. Multifrequency composite ultrasonic transducer system
US5025790A (en) * 1989-05-16 1991-06-25 Hewlett-Packard Company Graded frequency sensors
US5291090A (en) * 1992-12-17 1994-03-01 Hewlett-Packard Company Curvilinear interleaved longitudinal-mode ultrasound transducers

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7728490B2 (en) 2004-06-07 2010-06-01 Olympus Corporation Capacitive micromachined ultrasonic transducer

Also Published As

Publication number Publication date
JPH07107595A (en) 1995-04-21
CA2129946A1 (en) 1995-03-08
AU688334B2 (en) 1998-03-12
EP0641606B1 (en) 2000-02-02
DE69422867D1 (en) 2000-03-09
AU7020994A (en) 1995-03-23
AT189415T (en) 2000-02-15
EP0641606A3 (en) 1996-06-12
CA2129946C (en) 1998-09-29
EP0641606A2 (en) 1995-03-08
DE69422867T2 (en) 2000-12-07

Similar Documents

Publication Publication Date Title
JP6396319B2 (en) Ultrasonic transducer and intravascular ultrasonic imaging system
Shung Diagnostic ultrasound: Imaging and blood flow measurements
US9517053B2 (en) Dual-mode piezocomposite ultrasonic transducer
Gibbs et al. Ultrasound physics and technology e-book: how, why and when
US8708935B2 (en) System and method for variable depth ultrasound treatment
US20130296697A1 (en) Imaging, Therapy, and Temperature Monitoring Ultrasonic system and Method
Fink et al. Time reversal acoustics
US9730676B2 (en) Ultrasound imaging system using beamforming techniques for phase coherence grating lobe suppression
US6540683B1 (en) Dual-frequency ultrasonic array transducer and method of harmonic imaging
US4550606A (en) Ultrasonic transducer array with controlled excitation pattern
US5291090A (en) Curvilinear interleaved longitudinal-mode ultrasound transducers
US5434827A (en) Matching layer for front acoustic impedance matching of clinical ultrasonic tranducers
Brown et al. Fabrication and performance of a 40-MHz linear array based on a 1-3 composite with geometric elevation focusing
US4183249A (en) Lens system for acoustical imaging
US4276491A (en) Focusing piezoelectric ultrasonic medical diagnostic system
JP5275798B2 (en) Ultrasound imaging method
US4084582A (en) Ultrasonic imaging system
EP1504289B1 (en) Ultrasound transducer
US4570488A (en) Ultrasonic sector-scan probe
US7678054B2 (en) Ultrasonic probe and ultrasonic diagnosing device
Montaldo et al. Coherent plane-wave compounding for very high frame rate ultrasonography and transient elastography
JP4625145B2 (en) Acoustic vibrator and image generation apparatus
Seo et al. A 256 x 256 2-D array transducer with row-column addressing for 3-D rectilinear imaging
US5834687A (en) Coupling of acoustic window and lens for medical ultrasound transducers
US6618206B2 (en) System and method for acoustic imaging at two focal lengths with a single lens

Legal Events

Date Code Title Description
R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20081003

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20081003

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20091003

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20091003

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20101003

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111003

Year of fee payment: 8

S111 Request for change of ownership or part of ownership

Free format text: JAPANESE INTERMEDIATE CODE: R313111

S531 Written request for registration of change of domicile

Free format text: JAPANESE INTERMEDIATE CODE: R313531

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111003

Year of fee payment: 8

R350 Written notification of registration of transfer

Free format text: JAPANESE INTERMEDIATE CODE: R350

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20111003

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20121003

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20131003

Year of fee payment: 10

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

EXPY Cancellation because of completion of term