Abstract: In an actuator (50), a bobbin (511) to which a voice coil (513) is attached is disposed within a magnetic path space formed by a magnetic path forming section (52). A connecting shaft (514) is coupled to the bobbin (511), and a connection end portion (516A) at a distal end of the connecting shaft is connected to a sound board of a musical instrument. The length of the shaft (514) can be adjusted. When the actuator (50) is attached to the sound board, the length of the shaft (514) is adjusted and the connection end portion (516A) is connected to the sound board while a position of the voice coil (513) within the magnetic path space is maintained in a predetermined reference mounting position, in a state in which the magnetic path forming unit (52) is supported in a predetermined position by a support unit (55).

Abstract: In response to an operation of a key, a drive signal indicating a sound waveform corresponding to the key is supplied to an excitation unit provided on a soundboard. The soundboard is vibrated in response to a mechanical vibration generated by the excitation unit and generates an actively-vibrated-soundboard sound as well as an acoustic effect generated by propagation of the vibration of the soundboard to a string. The excitation unit has a voice coil excited by the drive signal. The length of the voice coil is equal to or smaller than a sum of a magnetic path width (mw) of a magnetic path space and a double of a maximum deflection amount (sw) of the vibration member connected to the soundboard. In this way, an effective drive force for exciting the soundboard can be obtained and an enhanced responsiveness in a high frequency band can be obtained.

Abstract: An automatic player piano is equipped with solenoid-operated actuators for moving keys in automatic performance without fingering of a human player, and an overheat protector is provided for the solenoid-operated actuators so as to prevent the solenoid-operated actuators from overheat; the overheat protector includes not only a temperature sensor and a rescuer but also an information processor, and a computer program runs on the information processor so as to realize a temperature rise estimator for estimating a solenoid temperature on the basis of the amount of current flowing through the solenoid and an environmental temperature determined through the temperature sensor estimator and an overheat detector so as to find an overheated solenoid, thereby making the rescuer interrupt the current for preventing the solenoid-operated actuator from the overheat.

Abstract: A soundboard acoustic transducer, including: a main body; and a vibrator configured to vibrate a soundboard in response to a sound signal input thereto, wherein the main body is supported by a member different from the soundboard, via a fixture formed by a metal plate.

Abstract: A keyboard musical instrument, including: a key; a board; a first member formed of a material different from a material of the board; a first acoustic transducer configured to vibrate the board in accordance with a drive signal supplied thereto; and a second acoustic transducer configured to vibrate the first member in accordance with a drive signal supplied thereto.

Abstract: In response to an operation of a key, a drive signal indicating a sound waveform corresponding to the key is supplied to an excitation unit provided on a soundboard. The soundboard is vibrated in response to a mechanical vibration generated by the excitation unit and generates an actively-vibrated-soundboard sound as well as an acoustic effect generated by propagation of the vibration of the soundboard to a string. The excitation unit has a voice coil excited by the drive signal. The length of the voice coil is equal to or smaller than a sum of a magnetic path width (mw) of a magnetic path space and a double of a maximum deflection amount (sw) of the vibration member connected to the soundboard. In this way, an effective drive force for exciting the soundboard can be obtained and an enhanced responsiveness in a high frequency band can be obtained.

Abstract: In a predetermined sound generation mode, a drive signal having a frequency characteristic corresponding to an operated key is supplied to excitation units provided on a soundboard. The soundboard is vibrated in response to a mechanical vibration generated by the excitation units to generate an acoustic sound by the vibration of the soundboard. The frequency characteristics of the drive signal to be supplied to each of the excitation units is set in association with the vibration characteristics of the soundboard at a position of a vibration member of each excitation unit connected to the soundboard. For example, the frequency characteristics of the drive signal is set to characteristics capable of suppressing resonance of the soundboard.

Abstract: In a predetermined sound generation mode, a drive signal having a frequency characteristic corresponding to an operated key is supplied to an excitation unit provided on a soundboard. In response to a mechanical vibration generated by the excitation unit, the soundboard is vibrated so as to generate an acoustic vibration sound corresponding to the operated key. The excitation unit is supported by a supporting unit such that less or no load of the excitation unit except a vibration member vibrated in response to the drive signal is applied to the soundboard. Thus, only a load of the vibration member which is a very light portion of the excitation unit is applied to the soundboard, thereby vibration characteristics of the soundboard being hardly affected. When a sound damping mode is selected, a stopper is permitted to prevent a hammer from striking a sounding body.

Abstract: An automatic player piano is equipped with solenoid-operated actuators for moving keys in automatic performance without fingering of a human player, and an overheat protector is provided for the solenoid-operated actuators so as to prevent the solenoid-operated actuators from overheat; the overheat protector includes not only a temperature sensor and a rescuer but also an information processor, and a computer program runs on the information processor so as to realize a temperature rise estimator for estimating a solenoid temperature on the basis of the amount of current flowing through the solenoid and an environmental temperature determined through the temperature sensor estimator and an overheat detector so as to find an overheated solenoid, thereby making the rescuer interrupt the current for preventing the solenoid-operated actuator from the overheat.