Electroacoustic transducer and electroacoustic transducer apparatus

• US 10,805,722 B2
• Filed: 10/25/2017
• Issued: 10/13/2020
• Est. Priority Date: 10/28/2016
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nakagawa, Toshiyuki, Ohashi, Yoshio
• Primary Examiner(s): Hamid, Ammar T
• Application Number:
  US16/343,543
• Publication Number:
  US 20190320262A1
• Time in Patent Office: 1,084 Days
• Field of Search: 381 55
• CPC Class Codes: 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
• CPC Class Codes: H04R 3/007 Protection circuits for transducers
• CPC Class Codes: H04R 3/04 for correcting frequency response
• CPC Class Codes: H04R 3/12 for distributing signals to two or more loudspeakers specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 31/003 for diaphragms or their outer suspension
• CPC Class Codes: H04R 7/10 comprising superposed layers in contact
• CPC Class Codes: H04R 7/125 comprising a plurality of superposed layers in contact
• CPC Class Codes: H04R 7/127 dome-shaped

Abstract

The present technology relates to an electroacoustic transducer and an electroacoustic transducer apparatus that are compact, have good characteristics, and can retain their stable shape.

The electroacoustic transducer includes: a first sheet including a sheet-like piezoelectric material and having a curved shape; and a second sheet having substantially the same shape as the first sheet and placed on the first sheet in a layered manner. The present technology can be applied to an electroacoustic transducer.

Claims

1. An electroacoustic transducer comprising:

a first sheet including a sheet-like piezoelectric material and having a curved shape;

a second sheet having substantially a same shape as the first sheet and placed on the first sheet in a layered manner, wherein the second sheet is a nonwoven fabric; and

a third sheet including a sheet-like piezoelectric material, having substantially a same shape as the first sheet, and placed in a layered manner on an opposite side of the second sheet that is not in contact with the first sheet.

2. The electroacoustic transducer according to claim 1, wherein

the second sheet includes a piezoelectric material.

3. The electroacoustic transducer according to claim 1, wherein

the second sheet is bonded to the first sheet.

4. The electroacoustic transducer according to claim 1, wherein

the first sheet and the second sheet are fixed by sandwiching and pressing a press portion provided at an end portion of the first sheet and the second sheet between a frame fixing member and a frame base.

5. The electroacoustic transducer according to claim 4, wherein

the frame fixing member and the frame base include opening portions for exposing the first sheet and the second sheet.

6. The electroacoustic transducer according to claim 5, wherein

a tapered portion is formed on at least one of the frame fixing member or the frame base such that the opening portion has varying widths in a first direction in which the frame fixing member and the frame base are aligned when viewed from a second direction substantially perpendicular to the first direction.

7. The electroacoustic transducer according to claim 6, wherein

the tapered portion is formed such that the opening portion becomes wider toward a position farthest from the first sheet and the second sheet in the first direction.

8. The electroacoustic transducer according to claim 6, wherein

the tapered portion is formed such that the opening portion becomes narrower toward a position farthest from the first sheet and the second sheet in the first direction.

9. An electroacoustic transducer apparatus comprising:

a first electroacoustic transducer having;

a first sheet having a curved shape and including a sheet-like piezoelectric material;

a second sheet having substantially a same shape as the first sheet and placed on the first sheet in a layered manner, wherein the second sheet is a nonwoven fabric; and

a third sheet including a sheet-like piezoelectric material, having substantially a same shape as the first sheet, and placed in a layered manner on an opposite side of the second sheet that is not in contact with the first sheet; and

a second electroacoustic transducer having a fourth sheet including a sheet-like piezoelectric material, having a curved shape, and having an area different from an area of the first sheet and of the second sheet.

10. The electroacoustic transducer apparatus according to claim 9, wherein

the first electroacoustic transducer or the second electroacoustic transducer is a low-frequency electroacoustic transducer, and a protection adjustment unit is connected to the low-frequency electroacoustic transducer to protect the low-frequency electroacoustic transducer and adjust frequency characteristics.

11. The electroacoustic transducer apparatus according to claim 10, wherein

the protection adjustment unit is a protection resistor or a low-pass filter.

12. An electroacoustic transducer apparatus comprising:

a first electroacoustic transducer having;

a first sheet having a curved shape and including a sheet-like piezoelectric material;

a second sheet having substantially a same shape as the first sheet and placed on the first sheet in a layered manner, wherein the second sheet is a nonwoven fabric; and

a third sheet including a sheet-like piezoelectric material, having substantially a same shape as the first sheet, and placed in a layered manner on an opposite side of the second sheet that is not in contact with the first sheet; and

a second electroacoustic transducer having;

a fourth sheet having a curved shape and including a sheet-like piezoelectric material; and

a fifth sheet having substantially a same shape as the fourth sheet and placed on the fourth sheet in a layered manner, the fourth sheet and the fifth sheet having an area different from an area of the first sheet and the second sheet.