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US 5,062,140 AGranted
Induction speaker
AssigneeSony Corporation
InventorsKiyofumi Inanaga, Hiroyuki Sogawa, Shiro Tsukamoto
Life of this patent
Estimating the term…
Abstract
In a speaker which comprises a diaphragm having a vibrating portion and an annular conductive portion, a current feeding coil facing the conductive portion with a predetermined gap therebetween, and a magnetic circuit including a top plate, a magnet and a yoke plate to which the current feeding coil is attached; the diaphragm is formed so that an electrical resistance of its conductive portion is lower than an electrical resistance of its vibrating portion.
Claims26
A speaker comprising:
- means defining a magnetic circuit having confronting annular surfaces that are radially spaced apart to form a gap therebetween;
- a current feeding coil mounted on one of said annular surfaces and being spaced from the other of said annular surfaces;
- a substantially dome-shaped diaphragm having an electrically conductive cylindrical edge portion which is an integral part thereof and which extends axially into said annular gap between said current feeding coil and said other annular surface of the magnetic circuit with clearances therebetween, said cylindrical edge portion of the diaphragm having an electrical resistance substantially lower than an electrical resistance of the remainder of said diaphragm;
- and
- means mounting said diaphragm for vibratory movement as a unit relative to said magnetic circuit in directions parallel with a central axis of said cylindrical edge portion of the diaphragm.
2 more elements
A speaker comprising:
- means defining a magnetic circuit having confronting annular surfaces that are radially spaced apart to form a gap therebetween;
- a current feeding coil mounted on one of said annular surfaces and being spaced from the other of said annular surfaces;
- a substantially dome-shaped diaphragm having an electrically conductive cylindrical edge portion which is an integral part thereof and which extends axially into said annular gap between said current feeding coil and said other annular surface of the magnetic circuit with clearances therebetween;
- and
- means mounting said diaphragm for vibratory movement as a unit relative to said magnetic circuit in directions parallel with a central axis of said cylindrical edge portion of the diaphragm, and including a damper member integral with said electrically conductive cylindrical edge portion and extending to said magnetic circuit, and means in said damper member for restricting current flow therethrough from said electrically conductive cylindrical edge portion.
2 more elements
A speaker comprising:
- means defining a magnetic circuit having confronting annular surfaces that are radially spaced apart to form a gap therebetween;
- a current feeding coil mounted on one of said annular surfaces and being spaced from the other of said annular surfaces;
- a substantially dome-shaped diaphragm having an electrically conductive cylindrical edge portion which is an integral part thereof and which extends axially into said annular gap between said current feeding coil and said other annular surface of the magnetic circuit with clearances therebetween, said cylindrical edge portion of the diaphragm having an electrical resistance substantially lower than an electrical resistance of the remainder of said diaphragm;
- means mounting said diaphragm for vibratory movement as a unit relative to said magnetic circuit in directions parallel with a central axis of said cylindrical edge portion of the diaphragm;
- and
- a viscous magnetic fluid filling said clearances for increasing magnetic flux density in said gap, transferring heat generated in said conductive cylindrical edge portion to said magnetic circuit and controlling a resonant characteristic of said vibratory movement.
3 more elements
A speaker comprising:
- means defining a magnetic circuit having confronting annular surfaces that are radially spaced apart to form a gap therebetween;
- a current feeding coil mounted within said gap on one of said annular surfaces and being spaced from the other of said annular surfaces, said coil consisting of flat wire having a substantially rectangular cross-section with a relatively large dimension thereof extending in a direction across said gap and corresponding to the thickness of said coil in said direction, and with said flat wire being helically wound to provide successive turns of said coil which contact each other over the entire extent of said relatively large dimension for improving heat transmission within said coil and dissipation of the heat therefrom, and for optimizing the mass of said coil that can be accommodated within said gap;
- a substantially dome-shaped diaphragm having an electrically conductive cylindrical edge portion which is an integral part thereof and which extends axially into said annular gap between said current feeding coil and said other annular surface of the magnetic circuit with clearances therebetween, said cylindrical edge portion of the diaphragm having an electrical resistance substantially lower than an electrical resistance of the remainder of said diaphragm;
- and
- means mounting said diaphragm for vibratory movement as a unit relative to said magnetic circuit in directions parallel with a central axis of said cylindrical edge portion of the diaphragm.
2 more elements
Dependencies are inferred from the claim text.