# US 12,120,960 B2 · Piezoelectric speaker

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- Number: US 12,120,960 B2
- Document ID: US12120960B2
- Status: Granted
- Kind: B2
- Application number: 16/765,796
- Filed: 2018-11-20
- Published: 2020-09-10
- Granted: 2024-10-15
- Earliest claimed: 2017-11-21
- Assignees: Nitto Denko Corporation
- Applicants: Nitto Denko Corporation
- Inventors: Yusuke Komoto; Kohei Oto; Saori Yamamoto; Ryohei Oban; Tomoaki Hishiki
- Web page: https://patentgrep.com/patent/US12120960B2

## CPC

- H04R 17/005: {using a piezoelectric polymer}
- H10N 30/857: Macromolecular compositions
- B32B 5/022: {Non-woven fabric}
- B32B 5/18: characterised by features of a layer {of} foamed material
- B32B 5/245: {another layer next to it being a foam layer}
- B32B 7/025: Electric or magnetic properties
- B32B 7/06: permitting easy separation
- B32B 7/12: using interposed adhesives or interposed materials with bonding properties
- B32B 9/005: {comprising one layer of ceramic material, e.g. porcelain, ceramic tile (layered products with at least two ceramic layers composed mainly of ceramic B32B18/00)}
- B32B 9/041: {of metal}
- B32B 9/043: {of natural rubber or synthetic rubber}
- B32B 9/045: {of synthetic resin}
- B32B 9/046: {of foam}
- B32B 9/047: {made of fibres or filaments}
- B32B 15/046: {of foam}
- B32B 15/06: of {natural rubber or synthetic} rubber
- B32B 15/082: comprising vinyl resins; comprising acrylic resins
- B32B 15/085: comprising polyolefins
- B32B 15/09: comprising polyesters
- B32B 15/095: comprising polyurethanes
- B32B 15/14: next to a fibrous or filamentary layer
- B32B 15/18: comprising iron or steel {(B32B15/011, B32B15/012 and B32B15/013 take precedence)}
- B32B 15/20: comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)}
- B32B 25/08: of synthetic resin
- B32B 25/10: next to a fibrous or filamentary layer
- B32B 25/12: comprising natural rubber
- B32B 25/14: comprising {synthetic rubber copolymers (B32B25/18 and B32B25/20 take precedence)}
- B32B 25/16: comprising polydienes {homopolymers} or poly-halodienes {homopolymers (B32B25/12 takes precedence)}
- B32B 25/18: comprising butyl or halobutyl rubber
- B32B 27/065: {of foam}
- B32B 27/08: of synthetic resin
- B32B 27/12: next to a fibrous or filamentary layer
- B32B 27/283: {comprising polysiloxanes}
- B32B 27/304: {comprising vinyl halide (co)polymers, e.g. PVC, PVDC, PVF, PVDF}
- B32B 27/308: {comprising acrylic (co)polymers}
- B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)}
- B32B 27/36: comprising polyesters
- B32B 27/40: comprising polyurethanes
- H04R 17/00: Piezoelectric transducers; Electrostrictive transducers (piezoelectric or electrostrictive elements in general H10N30/00; details of piezoelectric or electrostrictive motors, generators or positioners {H10N30/00})
- H10N 30/2047: {Membrane type}
- H10N 30/704: {based on piezoelectric or electrostrictive films or coatings}
- B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer
- B32B 2255/205: Metallic coating
- B32B 2266/0207: Materials belonging to B32B25/00
- B32B 2266/0278: Polyurethane
- B32B 2266/045: Metal
- B32B 2266/06: Open cell foam
- B32B 2266/08: Closed cell foam
- B32B 2266/10: characterised by the foam pores
- B32B 2307/10: having particular acoustical properties
- B32B 2307/20: having particular electrical or magnetic properties, e.g. piezoelectric
- B32B 2307/51: Elastic
- B32B 2307/732: Dimensional properties
- B32B 2307/748: Releasability
- B32B 2457/00: Electrical equipment
- H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K)
- H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM

## Abstract

A piezoelectric speaker (10) includes a piezoelectric film (35), a first joining layer (51), and an interposed layer (40). The piezoelectric film (35) includes a first electrode (61), a second electrode (62), and a piezoelectric body (30) sandwiched by the first electrode (61) and the second electrode (62). The first joining layer (51) is a layer having pressure-sensitive adhesiveness or adhesiveness. The interposed layer (40) is disposed between the piezoelectric film (35) and the first joining layer (51). Both principal surfaces of the piezoelectric film (35) vibrate up and down as a whole.

## Claims

### Claim 1

A piezoelectric speaker, comprising:
a piezoelectric film comprising a first electrode, a second electrode, and a piezoelectric body sandwiched by the first electrode and the second electrode;
a first joining layer having pressure-sensitive adhesiveness or adhesiveness;
an interposed layer disposed between the piezoelectric film and the first joining layer; and
a second joining layer having pressure-sensitive adhesiveness or adhesiveness, wherein
both principal surfaces of the piezoelectric film vibrate up and down as a whole,
the second joining layer is disposed between the first electrode and the interposed layer,
the first electrode includes a first surface as one of the principal surfaces of the piezoelectric film,
the second joining layer includes a second surface and a third surface,
the interposed layer includes a fourth surface,
the second surface is in immediate physical contact with the first surface, and
the third surface is in immediate physical contact with the fourth surface.

### Claim 2 (depends on 1)

The piezoelectric speaker according to claim 1, wherein the first joining layer and the interposed layer each have a uniform thickness.

### Claim 3 (depends on 1)

The piezoelectric speaker according to claim 1, wherein
the first joining layer comprises a first joining face, and
the first joining face is
(i) a bare surface, or
(ii) covered by a release layer capable of being separated from the first joining face, the release layer having a film and a release agent applied to a principal surface on the first joining face side of the film.

### Claim 4 (depends on 1)

The piezoelectric speaker according to claim 1, wherein the interposed layer is a resin layer and/or a porous body layer.

### Claim 5 (depends on 4)

The piezoelectric speaker according to claim 4, wherein the interposed layer is a resin layer and/or a porous body layer other than an adhesive layer and a pressure-sensitive adhesive layer.

### Claim 6 (depends on 1)

The piezoelectric speaker according to claim 1, wherein the interposed layer is in immediate physical contact with the first joining layer.

### Claim 7 (depends on 1)

The piezoelectric speaker according to claim 1, further comprising a first electrical pathway electrically connected to the first electrode, wherein
the first electrical pathway includes a first portion disposed so that at least a portion of the first electrode overlaps the first portion when the piezoelectric film is viewed in plan, and
a size of the first portion with respect to a thickness direction of the piezoelectric film is smaller than a thickness of the interposed layer.

### Claim 8 (depends on 1)

The piezoelectric speaker according to claim 1, further comprising a first electrical pathway electrically connected to the first electrode, wherein
the first electrical pathway includes a first portion disposed so that at least a portion of the first electrode overlaps the first portion when the piezoelectric film is viewed in plan, and
a size of the first portion with respect to a thickness direction of the piezoelectric film is smaller than a thickness of the second joining layer.

### Claim 9 (depends on 1)

The piezoelectric speaker according to claim 1, further comprising a first electrical pathway electrically connected to the first electrode, wherein
the first electrical pathway is spaced from the interposed layer.

### Claim 10 (depends on 1)

The piezoelectric speaker according to claim 1, wherein
the interposed layer is disposed on a region accounting for 90% or more of the area of the piezoelectric film when the piezoelectric film is viewed in plan.

### Claim 11 (depends on 1)

The piezoelectric speaker according to claim 1, wherein the interposed layer is configured to have a holding degree of 1×104 N/m3 or more and 5×108 N/m3 or less.

### Claim 12

A piezoelectric speaker, comprising:
a piezoelectric film comprising a first electrode, a second electrode, and a piezoelectric body sandwiched by the first electrode and the second electrode, wherein the piezoelectric film includes a principal surface, the principal surface being on a side of an interposed layer and defined as a supported face;
a first joining layer having pressure-sensitive adhesiveness or adhesiveness;
the interposed layer disposed between the piezoelectric film and the first joining layer; and
a second joining layer joining the interposed layer to an entirety of the supported face of the piezoelectric film,
wherein
the second joining layer is a layer having pressure-sensitive adhesiveness or adhesiveness,
the first electrode includes a first surface as the supported face,
the second joining layer includes a second surface and a third surface,
the interposed layer includes a fourth surface,
the second surface is in immediate physical contact with the first surface,
the third surface is in immediate physical contact with the fourth surface.

### Claim 13 (depends on 12)

The piezoelectric speaker according to claim 12, wherein
the interposed layer is in immediate physical contact with the first joining layer.

### Claim 14 (depends on 12)

The piezoelectric speaker according to claim 12, further comprising a first electrical pathway electrically connected to the first electrode, wherein
the first electrical pathway includes a first portion disposed so that at least a portion of the first electrode overlaps the first portion when the piezoelectric film is viewed in plan, and
a size of the first portion with respect to a thickness direction of the piezoelectric film is smaller than a thickness of the interposed layer.

### Claim 15 (depends on 12)

The piezoelectric speaker according to claim 12, further comprising a first electrical pathway electrically connected to the first electrode, wherein
the first electrical pathway includes a first portion disposed so that at least a portion of the first electrode overlaps the first portion when the piezoelectric film is viewed in plan, and
a size of the first portion with respect to a thickness direction of the piezoelectric film is smaller than a thickness of the second joining layer.

### Claim 16 (depends on 12)

The piezoelectric speaker according to claim 12, further comprising a first electrical pathway electrically connected to the first electrode, wherein
the first electrical pathway is spaced from the interposed layer.

### Claim 17 (depends on 12)

The piezoelectric speaker according to claim 12, wherein the interposed layer is configured to have a holding degree of 1×104 N/m3 or more and 5×108 N/m3 or less.