| 摘要 |
PROBLEM TO BE SOLVED: To constitute a central pole on a speaker by not receiving an influence of an external magnetic field as an eccentric rotor in a flat type brushless vibration motor and to facilitate fixing of an eccentric weight and mounting of a motor by a simple constitution without sacrificing its thickness. SOLUTION: The flat type brushless vibration motor is provided with an eccentric rotor R provided with an axial gap type magnet 9 and a rotor case 10; a shaft 12 for supporting the eccentric rotor; a stator base 11 arranged with a plurality of air-core electric element coils 14 for driving the eccentric rotor through the axial gap; and a housing H for storing these. The motor is provided with a vibration thin plate 3 having a flange part 10c coaxial to a rotation center formed on the whole periphery of the rotor case in a radial direction, an arch-like non-magnetic eccentric weight W arranged on a part of the flange part, one end of a movable voice coil arranged so as to face to an outer periphery through the gap and an outer periphery arranged on the speaker housing; and an excitation magnet 4 facing to the outer periphery of the movable coil through the gap. COPYRIGHT: (C)2006,JPO&NCIPI |
