Electroacoustic transducer
AssigneeStar Micronics Co., Ltd.
InventorsYoshio Imahori, Isao Fushimi, Katsutoshi Nito
Life of this patent
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Abstract
An electroacoustic transducer converts an electric signal into sound by vibrating a diaphragm magnetically in response to the electric signal input thereto. A movement restricting means for restricting the movement of the diaphragm within an allowable movement range is provided on the inner wall of a resonant chamber disposed at one side of the diaphragm. The restricting means normally confronts at a magnetic member attached to the center of the diaphragm. The restriction means contacts the magnetic member when the diaphragm attempts a deflection beyond the allowable range.
Claims12
An electroacoustic transducer for converting an electric signal applied thereto into sound, comprising:
- a cylindrical outer casing;
- a magnetic diaphragm coaxial with the casing and disposed in a middle portion of the outer casing;
- the diaphragm having a magnetic member fixed to one side of a central portion of the diaphragm for adding mass thereto;
- a resonant chamber formed inside the outer casing at a front end of the diaphragm;
- a sound emitting passageway connecting the resonant chamber to the atmosphere;
- magnetic driving means disposed at the other side of the diaphragm for inducing magnetic vibration in the diaphragm in response to the electric signal, the magnetic driving means including
- (a) a core;
- (b) a coil wound around the core and energized by the electric signal;
- and
- (c) a magnet which is disposed around the coil to generate a magnetic field passing through the diaphragm and magnetic member;
- means for restricting the movement range of the diaphragm located inside the resonant chamber of the outer casing and confronting the magnetic member;
- the restriction means having a surface for contracting the magnetic member upon deflection of the diaphragm beyond a preseletected amount thereby restricting the diaphragm movement.
Dependencies are inferred from the claim text.