| 摘要 |
PROBLEM TO BE SOLVED: To achieve a rapid linking operation of a hammer and a key based on a drive signal by causing the key to easily follow a rotation operation of the hammer with respect to a forward direction.SOLUTION: A plunger contact part 25 of a key 20 has an absorbing property for a magnetic pole. An electromagnetic actuator 30 includes a displacement member 31 composed of a forward moving coil 38, a reciprocating coil 39, and a soft magnetic material. The displacement member 31 is interposed between the key 20 and a hammer and transmits a rotation force of both elements to each other. When a drive signal generated by a signal control part based on an automatic musical performance data is transmitted to a solenoid control driver and a drive current is supplied to the forward moving coil 38, an upward thrust is given to the displacement member 31 and the hammer is rotationally driven to the forward direction, and a magnetic pole is formed in a key contact part 35 of the displacement member 31 by a magnetic field generated by the forward moving coil 38, and a plunger contact part 25 is absorbed by the key contact part and a rotation to the forward direction of the key 20 is assisted. |
