# US 9,521,490 B2 · Speaker diaphragm and production method for speaker diaphragm

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- Number: US 9,521,490 B2
- Document ID: US9521490B2
- Status: Granted
- Kind: B2
- Application number: 14/384,956
- Filed: 2013-03-13
- Published: 2015-01-08
- Granted: 2016-12-13
- Earliest claimed: 2012-03-14
- Assignees: Pioneer Corporation; Tohoku Pioneer Corporation; Mogami Denki Kabushiki Kaisha
- Applicants: Pioneer Corporation; Tohoku Pioneer Corporation; Mogami Denki Corporation
- Inventors: Kazuharu Kawata; Yoshihiro Sato; Hideki Takahashi
- Web page: https://patentgrep.com/patent/US9521490B2

## CPC

- H04R 7/04: Plane diaphragms
- H04R 7/125: {comprising a plurality of superposed layers in contact}
- H04R 9/025: {Magnetic circuit}
- H04R 31/003: {for diaphragms or their outer suspension}
- D21H 13/16: Polyalkenylalcohols; Polyalkenylethers; Polyalkenylesters
- H04R 2307/025: Diaphragms comprising polymeric materials
- H04R 2307/029: Diaphragms comprising fibres
- 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)
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR

## Abstract

A diaphragm can be obtained which exhibits large internal loss and Young's modulus and which can be produced efficiently. A speaker diaphragm 1 comprises at least one layer 1A formed by molding a component member configured by a fiber and a tangled fiber body of a synthetic fiber. The synthetic fiber is a polyvinyl alcohol fiber having boron.

## Claims

### Claim 1

A speaker diaphragm comprising a first layer and a second layer, wherein
said first layer has mica and is configured by a first component member, which is a tangled fiber body,
said tangled fiber body is configured by a natural fiber and a synthetic fiber different from said natural fiber, and
said synthetic fiber is a polyvinyl alcohol fiber having boron,
weight of the synthetic fiber is lower than weight of the natural fiber, and
said second layer being configured by a second component member, which is a tangled fiber body.

### Claim 2 (depends on 1)

The speaker diaphragm according to claim 1, wherein said synthetic fiber has a bending shape.

### Claim 3 (depends on 1)

The speaker diaphragm according to claim 1, wherein said mica is attached to said synthetic fiber.

### Claim 4 (depends on 1)

The speaker diaphragm according to claim 1, wherein
an internal loss of said speaker diaphragm is larger than 0.0216, and
a Young's modulus of said speaker diaphragm is larger than 4.40*109 N/m2.

### Claim 5 (depends on 1)

The speaker diaphragm according to claim 1, wherein a cross sectional shape of said synthetic fiber is a circular shape.

### Claim 6 (depends on 1)

A speaker device comprising:
the speaker diaphragm according to claim 1;
a voice coil; and
a magnetic circuit having a magnet.

### Claim 7 (depends on 6)

An electronic device comprising the speaker device according to claim 6.

### Claim 8 (depends on 6)

An automobile comprising the speaker device according to claim 6.