High efficient miniature electro-acoustic transducer with reduced dimensions
First Claim
Patent Images
1. A miniature electro-acoustic transducer comprising:
- a diaphragm and a voice coil operatively connected to the diaphragm; and
a magnetic circuit comprising an inner permanent magnet assembly and an outer permanent magnet assembly, a magnetically permeable yoke, and first and second air gap portions conducting first and second magnetic flux densities, respectively, the first and second air gap portions having first and second voice coil segments, respectively, arranged therein,wherein the magnetic flux density in the first air gap portion is generated by superposition of magnetic flux generated by the inner permanent magnet assembly and magnetic flux generated by the outer permanent magnet assembly, and wherein the magnetic flux density in the second air gap portion is generated substantially exclusively by the inner permanent magnet assembly.
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Abstract
The present invention relates to a miniature electro-acoustic transducer including a magnetic circuit, a diaphragm and a voice coil operatively connected to the diaphragm. The magnetic circuit includes first and second air gap portions adapted to receive first and second voice coil segments, respectively. The magnetic flux acting on the first voice coil segment is provided by inner magnetic means and first outer magnetic means in combination and the magnetic flux acting on the second voice coil segment is essentially provided by the inner magnetic means only.
26 Citations
21 Claims
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1. A miniature electro-acoustic transducer comprising:
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a diaphragm and a voice coil operatively connected to the diaphragm; and a magnetic circuit comprising an inner permanent magnet assembly and an outer permanent magnet assembly, a magnetically permeable yoke, and first and second air gap portions conducting first and second magnetic flux densities, respectively, the first and second air gap portions having first and second voice coil segments, respectively, arranged therein, wherein the magnetic flux density in the first air gap portion is generated by superposition of magnetic flux generated by the inner permanent magnet assembly and magnetic flux generated by the outer permanent magnet assembly, and wherein the magnetic flux density in the second air gap portion is generated substantially exclusively by the inner permanent magnet assembly. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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- 16. A miniature electro-acoustic transducer comprising a magnetic circuit, a diaphragm and a voice coil operatively connected to the diaphragm, wherein the magnetic circuit comprises first and second air gap portions adapted to receive first and second voice coil segments, respectively, wherein the first air gap portion is provided between inner magnetic means and first outer magnetic means, and wherein the second air gap portion is provided between said inner magnetic means and first outer pole piece means, and wherein the first and second air gap portions are arranged essentially perpendicular to each other.
- 18. A miniature electro-acoustic transducer comprising a magnetic circuit, a diaphragm and a voice coil operatively connected to the diaphragm, wherein the magnetic circuit comprises first and second air gap portions adapted to receive first and second voice coil segments, respectively, wherein magnetic flux acting on the first voice coil segment is provided by inner magnetic means and first outer magnetic means in combination, and wherein magnetic flux acting on the second voice coil segment is essentially provided by said inner magnetic means only.
- 20. A miniature electro-acoustic transducer comprising a magnetic circuit, a diaphragm and a voice coil operatively connected to the diaphragm, the magnetic circuit comprising first and second air gap portions adapted to receive first and second voice coil segments, respectively, wherein magnetic flux acting on the first voice coil segment is provided by inner magnetic means and outer magnetic means in combination, and wherein magnetic flux acting on the second voice coil segment is essentially provided by said inner magnetic means only, wherein the inner magnetic means and the outer magnetic means are configured so that the magnetic flux densities in the first air gap portion and the second air gap portion are essentially equal in strength.
Specification