# US 6,724,908 B2 · Method for producing electric-mechanical acoustic converter

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- Number: US 6,724,908 B2
- Document ID: US6724908B2
- Status: Granted
- Kind: B2
- Application number: 10/384,835
- Filed: 2003-03-10
- Published: 2003-09-11
- Granted: 2004-04-20
- Earliest claimed: 1997-10-30
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Takanori Fukuyama
- Web page: https://patentgrep.com/patent/US6724908B2

## CPC

- H04M 1/03: Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
- G10K 9/22: Mountings; Casings
- H04R 9/06: Loudspeakers
- H04R 2400/03: Transducers capable of generating both sound as well as tactile vibration, e.g. as used in cellular phones
- H04R 2400/07: Suspension between moving magnetic core and housing
- Y10T 29/49005: Acoustic transducer
- H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08)
- 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
- 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)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The present invention relates to an electric-mechanical-acoustic converter used mainly in a mobile telephone and the like, and its objective is to provide a high-quality product in which damage and degradation of performance caused by shock due to a drop are prevented. In order to achieve this objective, the present invention includes at least one suspension (14) supporting a movable portion (19) formed of the magnetic circuit portion (17) and a weight portion (13), and a frame (9) supporting a diaphragm (8) and the suspension (14), a space in an elastic deformation range of the suspension (14) being provided between the outer periphery of the movable portion (19) and the frame (9). Even in the case where a portable terminal apparatus is dropped, and the electric-mechanical-acoustic converter built therein is subjected to shock, the outer periphery of the movable portion (19) is received by the frame (9), whereby the suspension (14) can be prevented from being permanently deformed.

## Claims

### Claim 1

A method for producing an electric-mechanical-acoustic converter, said method comprising:
positioning a diaphragm and a magnetic circuit such that the diaphragm opposes the magnetic circuit;
attaching one end of a voice coil to the diaphragm, and inserting the voice coil into a magnetic gap of the magnetic circuit with a predetermined space;
integrating a weight with the magnetic circuit or attaching the weight thereto as a separate component;
supporting a moveable portion composed of the magnetic circuit and the weight with at least one suspension;
supporting the diaphragm and the suspension in a frame, wherein a space in an elastic deformation range of the suspension between an outer periphery of the movable portion and an inner diameter of the frame is smaller than a space between the magnetic gap and the voice coil;
forming on a lead frame and integrally molded therewith, the suspension and a lead terminal through which an electric signal is applied from outside to the voice coil.