Patent attributes
In a bone conduction speaker, a body has a shape of a cylinder, and a vibrating plate is inserted to a mastoid to close an upper opening portion of the body. An auxiliary vibrating plate is inserted to the mastoid under the vibrating plate. A vibrating coil is attached on a lower side of the auxiliary vibrating plate. A speaker plate is fixed at an inner central portion of the body, and a ring type magnet is fixed on the speaker plate. An edge portion of a yoke is fixed on the ring type magnet and a central portion of the yoke has a protrusion which protrudes in the inside direction of a central hole of the speaker plate. An acoustic vibrating plate is fixed at a lower portion of the body, and an acoustic coil is fixed on the acoustic vibrating plate.
