Patent ID: 8593018

Claim:
A vibration generator comprising: a mechanical vibrator having a first ring-shaped permanent magnet with a front and back comprised of an N pole face and an S pole face; a fastening part supporting said mechanical vibrator in a plate thickness direction spanning said N pole face and said S pole face through a suspension spring means; a magnetic core member supported by said fastening part and passing through a center hole of said first ring-shaped permanent magnet; and a first toroidal coil fitting over an outer circumferential surface of said magnetic core member and facing an inner circumferential surface of said center hole, wherein said mechanical vibrator is provided with a first ring-shaped pole piece superposed over at least one magnetic pole face among said N pole face and said S pole face, said first ring-shaped pole piece having an inner circumferential edge approaching an outer circumferential surface of said first toroidal coil, wherein said mechanical vibrator further comprises a second ring-shaped pole piece superposed over one of said pole faces of said first ring-shaped permanent magnet, the magnetic polarity of said one of said pole faces being opposite to the magnetic polarity of said first ring-shaped pole piece, said second ring-shaped pole piece having an inner circumferential edge approaching said outer circumferential surface of said magnetic core member.