# US 4,398,116 A · Transducer for electronic focal scanning in an ultrasound imaging device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,398,116 A - Document ID: US4398116A - Status: Granted - Kind: A - Application number: 06/258,883 - Filed: 1981-04-30 - Granted: 1983-08-09 - Earliest claimed: 1981-04-30 - Assignees: Siemens Gammasonics, Inc. - Inventors: George K. Lewis - Web page: https://patentgrep.com/patent/US4398116A ## CPC - B06B 1/0625: {Annular array} - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) ## Abstract The ultrasonic transducer contains a plurality of adjacently positioned piezoelectric segments which are arranged concentrically. Each of the segments contains a number of linear parallel grooves, whereby these grooves define spaced surface areas therebetween. Each of the surface areas comprises respectively a piezoelectric element. The individual grooves are approximately annular when the segments are assembled. They decouple the piezoelectric elements acoustically from each other. Preferably, the segments each have a triangular shape. ## Claims ### Claim 1 An ultrasound transducer for electronic focal scanning comprising: (a) a plurality of adjacently positioned piezoelectric segments arranged concentrically, (b) each of said segments containing a plurality of individual, linear parallel grooves, (c) said individual grooves in each segment defining spaced surface areas therebetween, and each of said surface areas comprising respectively a piezoelectric element, and (d) said individual grooves in the concentric arrangement of said segments form concentric polyhedral grooves which are approximately annular and acoustically decouple said piezoelectric elements from each other, which piezoelectric elements thereby forming polygons which approximate a ring form. ### Claim 2 (depends on 1) The improvement according to claim 1, wherein each of said segments has two linear sides for positioning said segments close to each other. ### Claim 3 (depends on 1) The improvement according to claim 1, wherein said segments are triangular segments which are arranged symmetrically around said central axis. ### Claim 4 (depends on 3) The improvement according to claim 3, wherein an even number of segments is provided. ### Claim 5 (depends on 4) The improvement according to claim 4, wherein six segments are provided, each segment having two linear sides which form an angle of 60.degree. with each other. ### Claim 6 (depends on 1) The improvement according to claim 1, wherein between four and ten elevated piezoelectric areas are provided in each segment. ### Claim 7 (depends on 1) The improvement according to claim 1, wherein said elements are equally spaced from each other by said grooves. ### Claim 8 (depends on 1) The improvement according to claim 1, wherein said linear grooves extend through approximately 3/4 of the thickness of said segments. ### Claim 9 (depends on 1) The improvement according to claim 1, wherein all said segments are alike. ### Claim 10 (depends on 1) The improvement according to claim 1, wherein each of said segments has a first surface and a second surface which second surface is parallel to said first surface, wherein said grooves are provided in said first surface, wherein said second surface is provided with a common electrode which is electrically connected to the corresponding common electrodes of all other segments, and wherein said surface areas of said first surface are electrically connected to the corresponding surface areas of the adjacent segments. ### Claim 11 (depends on 1) The improvement according to claim 1, wherein said common electrode is provided with at least one acoustically matching layer. ### Claim 12 (depends on 1) The improvement according to claim 1, wherein at least two of said elements respond to respective different ultrasonic frequencies. ### Claim 13 (depends on 1) The improvement according to claim 1, wherein said surface areas of each segment have the same size. ### Claim 14 An ultrasound transducer for electronic focal scanning comprising: (a) a plurality of adjacently positioned piezoelectric segments arranged concentrically, (b) each of said segments containing a plurality of linear parallel grooves, said grooves defining spaced surface areas therebetween, and each of said surface areas comprising respectively a piezoelectric element, whereby said grooves are approximately annular and acoustically decouple said piezoelectric elements from each other; and (c) said surface areas of each segment have the same size, wherein the distance d.sub.n of the n.sup.th surface area from said central axis is determined according to ##EQU2## wherein d.sub.1 is the distance of the outer perimeter of the innermost element from said central axis.