Multielement acoustic transducer as well as a method of manufacturing the same and an acoustic imaging instrument

Claim 2

In an acoustic imaging instrument wherein a predetermined object to be imaged is mechanically scanned in two dimensions in a focal zone of a focussed acoustic beam, and an acoustic image of the object to be imaged is formed on the basis of the resultant acoustic beam; an acoustic imaging instrument characterized in that means to form the acoustic beam includes multielement transducer means for simultaneously transmitting and receiving each beam, the multielement transducer means including a plurality of acoustic transducer elements formed at intervals each being equal to a width of the mechanical scanning, and that each of the plurality of transducer elements has a concave construction.

Claim 3

An acoustic imaging instrument as defined in claim 1, characterized in that the plurality of transducer elements provide focussed acoustic beams of unequal focal distances.

Claim 4

An acoustic imaging instrument as defined in claim 1, characterized in that the transducer elements have piezoelectric thin films of unequal fundamental resonance frequencies.

Claim 5

An acoustic imaging instrument as defined in claim 1, characterized in that the respective transducer elements are driven by drive voltages of unequal RF frequencies.

Claim 6

An acoustic imaging instrument as defined in claim 1, wherein the multielement transducer means includes a transmitting multielement transducer array and a receiving multielement transducer array for simultaneously transmitting and receiving each beam.

Claim 7

An acoustic imaging instrument as defined in claim 5, wherein the transmitting multielement transducer array and the receiving multielement transducer array are arranged on opposite sides of the object to be imaged for simultaneously transmitting and receiving each beam.

Claim 8

An acoustic imaging instrument as defined in claim 1, wherein the plurality of acoustic transducer elements comprise a first metal thin film having a plurality of concave portions, a piezoelectric member formed on the first metal thin film, and a second metal thin film formed on the piezoelectric member, the first and second metal thin films being used as electrodes.

Claim 9

An acoustic imaging instrument as defined in claim 7, wherein the piezoelectric member and the second metal thin film have concave portions corresponding to the concave portions of the first metal thin film.

Claim 10

An acoustic imaging instrument as defined in claim 1, wherein the multielement acoustic transducer means is formed by the steps of grinding a bubble existent in a predetermined material to the vicinity of an equitorial plane of the bubble, fusing a low-melting metal into a concave surface formed by the bubble, separating the metal from the concave surface to obtain a member having a convex hemisphere of the metal, arranging a plurality of the metal members having the convex hemisphere, forming a metal thin film on the plurality of convex hemispheres, forming a predetermined piezoelectric material on the metal thin film, and forming a metal layer on the piezoelectric material.

Claim 11

A multielement acoustic transducer for an acoustic imaging instrument characterized in that a plurality of acoustic transducer means for generating focussed beams comprise a first metal thin film having a plurality of concave portions, a piezoelectric member formed on the metal thin film for generating a focussed acoustic beam from the piezoelectric member, and a second metal thin film formed on the piezoelectric member, the first and second metal thin films being used as electrodes, the multielement acoustic transducer being formed by the steps of grinding a bubble existent in a predetermined material to the vicinity of equitorial plane of the bubble, fusing a low-melting metal into a concave surface formed by the bubble, separating the metal from the concave surface to obtain a member having a convex hemisphere of the metal, arranging a plurality of the metal members having a convex hemisphere, forming a metal thin film on the plurality of convex hemispheres as the first metal thin film, forming a predetermined piezoelectric material on the first metal thin film as the piezoelectric member, and forming a metal layer on the piezoelectric material as the second metal thin film, and wherein a predetermined object to be imaged is mechanically scanned in two dimensions in a focal zone of a focussed acoustic beam, and an acoustic image of the object to be imaged is formed on the basis of a resultant acoustic beam, the plurality of acoustic transducer means being arranged for simultaneously transmitting and receiving each acoustic beam, the plurality of acoustic transducer means being formed at intervals equal to a width of the mechanical scanning.

Claim 12

A multielement acoustic transducer for an acoustic imaging instrument characterized in that a plurality of acoustic transducer means for generating focussed beams comprise a first metal thin film having a plurality of concave portions, a piezoelectric member formed on the metal thin film for generating a focussed acoustic beam from the piezoelectric member, and a second metal thin film formed on the piezoelectric member, the first and second metal thin films being used as electrodes, the multielement acoustic transducer being formed by the steps of grinding a bubble existent in a predetermined material to the vicinity of equitorial plane of the bubble, fusing a low-melting metal into a concave surface formed by the bubble, separating the metal from the concave surface to obtain a member having a convex hemisphere of the metal, arranging a plurality of the metal members having a convex hemisphere, forming a metal thin film on the plurality of convex hemispheres as the first metal thin film, forming a predetermined piezoelectric material on the first metal thin film as the piezoelectric member, and forming a metal layer on the piezoelectric material as the second metal thin film, and wherein a predetermined object to be imaged is mechanically scanned in two dimensions in a focal zone of a focussed acoustic beam, and an acoustic image of the object to be imaged is formed on the basis of a resultant acoustic beam, the plurality of acoustic transducer means being arranged for simultaneously transmitting and receiving each acoustic beam, the plurality of acoustic transducer means being formed at intervals equal to a width of the mechanical scanning.

Claim 13

A multielement acoustic transducer as defined in claim 10, wherein the plurality of acoustic transducer means includes a transmitting multielement transducer array and a receiving multielement transducer array for simultaneously transmitting and receiving each beam.

Claim 14

A multielement acoustic transducer as defined in claim 11, wherein the transmitting multielement transducer array and the receiving multielement transducer array are arranged on opposite sides of the object to be imaged.