US 6,724,909 B2Granted

Speaker apparatus

AssigneesFujitsu Ten Limited, Timedomain Corporation

InventorsKatsuhiko Tsumori, Akira Nishikawa, Hiroshi Kowaki, Hiroyuki Yoshii

Life of this patent

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Abstract

A weight is attached to the rear side of a magnetic circuit of a speaker unit. The tip of a boss that projects to the front side from the weight is joined to the rear side of a center pole of the magnetic circuit with a bolt. Even if reactive force that is generated when an electrical signal is converted into mechanical vibration by the magnetic circuit and a voice coil and sound waves are emitted from a vibration plate is transmitted to the magnetic circuit, the vibration of the magnetic circuit is suppressed by the weight. In this manner, sound quality with a good transient characteristic can be obtained.

Claims2

Dependent claims

A speaker apparatus comprising:

a speaker unit including a converter, having a magnetic circuit, for converting an electrical signal into mechanical vibration along an axial line direction of a voice coil, a vibration plate for emitting sound waves to a front side of the converter, and a frame fixed to the converter, for vibratably supporting the vibration plate from a rear side thereof;
and
a weight heavier than the speaker unit, having a boss formed so as to project to a front side from a central portion of the weight along the axial line of the voice coil, a cross section of the boss taken perpendicularly to the axial line being smaller than that of the magnetic circuit, a tip of the boss being fixed to a rear side of the magnetic circuit.

Dependencies are inferred from the claim text.

Facts

Application: 09/986,668Filed 9 Nov 2001
Priority: JP P2000-34421410 Nov 2000
Published: US 2002/0057821 A116 May 2002
Granted: 20 Apr 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04R 9/06
Transducers of moving-coil, moving-strip, or moving-wire type: loudspeakers
H04R 9/025
Details: magnetic circuit
H04R 2209/027
Details of transducers of the moving-coil, moving-strip, or moving-wire type covered by H04R9/00 but not provided for in any of its subgroups:…
H04R
Loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers

Family

US 2002/0057821 A1Pre-grant publication · published 16 May 2002
US 6,724,909 B2This patent

From the US filing history. Foreign family members aren’t listed.

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