# US 11,998,390 B2 · Piezoelectric actuator, ultrasound element, ultrasound probe, ultrasound device, and electronic device

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- Number: US 11,998,390 B2
- Document ID: US11998390B2
- Status: Granted
- Kind: B2
- Application number: 17/456,387
- Filed: 2021-11-24
- Published: 2022-05-26
- Granted: 2024-06-04
- Earliest claimed: 2020-11-25
- Assignees: Seiko Epson Corporation
- Applicants: Seiko Epson Corporation
- Inventors: Koji Ohashi; Chikara Kojima; Makoto Furuhata; Tomohide Onogi; Tomohiro Sayama
- Web page: https://patentgrep.com/patent/US11998390B2

## CPC

- A61B 8/4494: {characterised by the arrangement of the transducer elements}
- G10K 11/002: {Devices for damping, suppressing, obstructing or conducting sound in acoustic devices (G10K1/06 - G10K1/10 take precedence; for electro-mechanical transducers for communication H04R3/002)}
- A61B 8/4236: {characterised by adhesive patches}
- A61B 8/4427: {Device being portable or laptop-like}
- A61B 8/4444: {related to the probe}
- A61B 8/54: {Control of the diagnostic device}
- B06B 1/0207: {Driving circuits (specially adapted for particular applications, see the relevant subclass, e.g. G01; circuits for steering transducer arrays G10K11/34; basic circuits H03)}
- B06B 1/0622: {on one surface}
- B06B 1/0681: {and a damping structure}
- G01S 15/8906: {Short-range imaging systems; Acoustic microscope systems using pulse-echo techniques}
- B06B 2201/76: Medical, dental
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- 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)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES

## Abstract

A piezoelectric actuator includes a vibrating plate including a first surface that closes an opening provided in a substrate and a second surface in which a plurality of piezoelectric elements is provided, a suppression part configured to suppress a vibration of the vibrating plate, and a first wall and a second wall protruding from the first surface to the opening. When a portion where the first electrode, the piezoelectric layer and the second electrode overlap each other is an active part of the piezoelectric element, the first wall and the second wall are provided to sandwich the active part in plan view from the stacking direction of the first electrode, the piezoelectric layer and the second electrode, and the second wall is different from the first wall at least in one of the width, height, length and physical property.

## Claims

### Claim 1

A piezoelectric actuator comprising:
a substrate in which an opening is formed, the opening extending along a first direction in a plan view;
a vibrating plate having a first surface and a second surface outwardly opposite to each other, the first surface closing the opening;
a piezoelectric element provided, corresponding to the opening, at the second surface of the vibrating plate;
a sealing plate disposed on the second surface of the vibrating plate;
a suppression part configured to suppress a vibration of the vibrating plate, the suppression part being formed in the sealing plate, the suppression part being configured with a plurality of suppression walls extending along a second direction different from the first direction in the plan view, each of the plurality of suppression walls being sandwiched by two through-holes disposed in the sealing plate, each of the through-holes housing the piezoelectric element;
a first wall protruding from a first position of the first surface into the opening along a third direction different from the first and second directions; and
a second wall protruding from a second position of the first surface into the opening along the third direction, wherein
in the piezoelectric element, a first electrode, a piezoelectric layer, and a second electrode are stacked in this order from a side of the second surface,
when a portion where the first electrode, the piezoelectric layer, and the second electrode overlap each other is defined as an active part, the first wall and the second wall are provided to sandwich the active part in the plan view, and
the second wall is different from the first wall at least in one of a width along the second direction, a length along the first direction, and a physical property with respect to materials of the first and second walls.

### Claim 2 (depends on 1)

The piezoelectric actuator according to claim 1, wherein the suppression part is provided at the second surface of the vibrating plate.

### Claim 3 (depends on 2)

An ultrasound element comprising:
the piezoelectric actuator according to claim 2;
a transmission circuit configured to cause the piezoelectric actuator to transmit ultrasound waves; and
a reception circuit configured to cause the piezoelectric actuator to receive ultrasound waves.

### Claim 4 (depends on 3)

An ultrasound probe comprising:
the ultrasound element according to claim 3; and
a housing configured to house the ultrasound element.

### Claim 5 (depends on 3)

An ultrasound device comprising:
the ultrasound element according to claim 3; and
a controller configured to control the ultrasound element.

### Claim 6 (depends on 2)

An electronic device comprising the piezoelectric actuator according to claim 2.

### Claim 7 (depends on 1)

An ultrasound element comprising:
the piezoelectric actuator according to claim 1;
a transmission circuit configured to cause the piezoelectric actuator to transmit ultrasound waves; and
a reception circuit configured to cause the piezoelectric actuator to receive ultrasound waves.

### Claim 8 (depends on 7)

An ultrasound probe comprising:
the ultrasound element according to claim 7; and
a housing configured to house the ultrasound element.

### Claim 9 (depends on 7)

An ultrasound device comprising:
the ultrasound element according to claim 7; and
a controller configured to control the ultrasound element.

### Claim 10 (depends on 1)

An electronic device comprising the piezoelectric actuator according to claim 1.