Electric-mechanical-acoustic converter and method for producing the same

• US 6,570,993 B1
• Filed: 08/16/1999
• Issued: 05/27/2003
• Est. Priority Date: 10/30/1997
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fukuyama, Takanori
• Primary Examiner(s): LE, HUYEN D
• Application Number:
  US09/331,902
• Time in Patent Office: 1,380 Days
• Field of Search: 381/151, 381/396, 381/398, 381/412, 381/353, 381/354, 381/7.62, 381/7.63, 381/7.6, 340/311.1, 340/388.1
• US Class Current: 381/396
• CPC Class Codes: G10K 9/22 Mountings; Casings
• CPC Class Codes: H04M 1/03 Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets
• CPC Class Codes: H04R 2400/03 Transducers capable of generating both sound as well as tactile vibration, e.g. as used in cellular phones
• CPC Class Codes: H04R 2400/07 Suspension between moving magnetic core and housing
• CPC Class Codes: H04R 9/06 Loudspeakers
• CPC Class Codes: Y10T 29/49005 Acoustic transducer

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

1. An electric-mechanical-acoustic converter, comprising:

a diaphragm;

a magnetic circuit disposed so as to oppose the diaphragm;

a voice coil one end of which is attached to the diaphragm, inserted into a magnetic gap of the magnetic circuit with a predetermined space;

a weight integrated with the magnetic circuit or attached thereto as a separate component;

at least one suspension supporting a movable portion composed of the magnetic circuit and the weight; and

a frame supporting the diaphragm and the suspension, 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.

2. An electric-mechanical acoustic converter according to claim 1, wherein the suspension supports the movable portion at a position vertically symmetric with respect to a center of gravity of the movable portion.

3. An electric-mechanical-acoustic converter according to claim 1, wherein the suspension supports the movable portion in such a manner that a distance and stiffness are symmetrically distributed in an inverse ratio with respect to a center of gravity of the movable portion in a vertical direction.

4. An electric-mechanical-acoustic converter according to claim 1, wherein a connected portion of the suspension on the frame side is insert-molded to the frame.

5. An electric-mechanical-acoustic converter according to claim 4, wherein the connected portion of the suspension on the frame side is welded to a metal chip one end of which is insert-molded to the frame.

6. An electric-mechanical-acoustic converter according to claim 5, wherein the metal chip and a lead terminal which receives an electric signal from outside are formed on an identical lead frame and are integrally molded therewith.

7. An electric-mechanical-acoustic converter, comprising:

a diaphragm;

a magnetic circuit disposed so as to oppose the diaphragm;

a voice coil one end of which is attached to the diaphragm, inserted into a magnetic gap of the magnetic circuit with a predetermined space;

a weight integrated with the magnetic circuit or attached thereto as a separate component;

at least one suspension supporting a movable portion composed of the magnetic circuit and the weight; and

a frame supporting the diaphragm and the suspension, wherein one end of the suspension is molded with resin, and the mold portion is attached to the frame.

8. An electric-mechanical-acoustic converter according to claim 7, wherein one end of the suspension is molded with resin, and the mold portion is inserted to be fixed in a concave portion provided in the frame.

9. An electric-mechanical-acoustic converter, comprising:

a diaphragm;

a magnetic circuit disposed so as to oppose the diaphragm;

a voice coil, one end of which is attached to the diaphragm, inserted into a magnetic gap of the magnetic circuit with a predetermined space;

a weight integrated with the magnetic circuit or attached thereto as a separate component;

at least one suspension supporting a movable portion composed of the magnetic circuit and the weight; and

a frame supporting the diaphragm and the suspension,

wherein a connected portion of the suspension on the frame side is insert-molded to the frame and is welded to a metal chip, one end of which is insert-molded to the frame, and

the metal chip and a lead terminal which receives an electric signal from outside are formed on an identical lead frame and are integrally molded therewith.

10. An electric-mechanical-acoustic converter, comprising:

a diaphragm;

a movable portion composed of a magnetic circuit disposed so as to oppose the diaphragm;

a voice coil, one end of which is attached to the diaphragm, inserted into a magnetic gap of the magnetic circuit;

a suspension supporting the movable portion;

a frame supporting the diaphragm and the suspension; and

an elastic bushing covering the frame, provided with an opening at least on an outside of the movable portion for conducting a sound to a portable terminal, and interposed in the portable terminal,

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.