Acoustic transducer
AssigneeSony Corporation
InventorsMasao Fujihira, Makoto Yamagishi, Jun Kishigami, Takahiro Muraguchi, Kenji Tokushige, Ikuo Shinohara
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Abstract
An electromagnetic induction type acoustic transducer apparatus including a magnetic gap formed between a plate and a pole piece serving as assemblies of a magnetic circuit, a conductive ring attached to a diaphragm, the diaphragm interposed within the magnetic gap for generating sounds when it is vibrated, and a flat coil disposed in the plate or the pole piece at the position opposing the magnetic gap and of which winding is increased from the vibration direction of the diaphragm to the direction perpendicular to the vibration direction of the diaphragm, wherein a width of the magnetic gap can be reduced.
Claims5
An electromagnetic induction type acoustic transducer having an annular plate, a pole piece, a drive coil, and a non-magnetic diaphragm, the apparatus comprising:
- a magnetic gap formed between an inner diameter of said annular plate and said pole piece forming a magnetic circuit;
- a secondary coil formed of non-magnetic conductive material attached to said diaphragm interposed in said magnetic gap for vibratory movement in said magnetic gap, said diaphragm generating sounds upon being vibrated;
- and
- an annular drive coil housing portion disposed in one of said plate and said pole piece at a position opposing said magnetic gap and said drive coil being housed in said annular coil housing portion, wherein a dimension of said drive coil is increased in a direction perpendicular to a vibrating direction of said diaphragm, so that said drive coil is formed as an annular flat winding having a diametric width greater than a longitudinal thickness.
Dependencies are inferred from the claim text.