Abstract: A method for eliminating or reducing noise created by the action mechanisms of piano keys during its return stroke after striking a string, by regulating the amount of time for the mechanism to return to rest. The method comprises the steps of sequentially initiating a pair of braking pulses by the actuator solenoid to slow the action mechanism during its return stroke. Each braking pulse is of a specified duration and magnitude such that the mechanism's return time is maximized while eliminating the possibility of double hits on the string.

Abstract: A piano pedal optical sensor apparatus and method for accurately measuring, recording and reproducing the pedal expression generated during piano performances. A plurality of optical emitter/sensors are mounted on the pedal support assembly of a piano, and a plurality of corresponding optical reflectors are mounted on the moving connecting rods associated with piano pedals on the piano. Output voltage signals from the optical emitter sensors, which vary according to pedal movement, are monitored and used to generate and record pedal position values. The recorded pedal position values are then used to recreate the original pedal expression of the piano performance by generation of pulse width modulation signals which are used to drive solenoids associated with piano pedals.

Abstract: A method and apparatus for actuating solenoids in an electronic player piano where a Musical Instrument Digital Interface (MIDI) velocity value is translated to a solenoid driving signal, a counter is activated by the solenoid driving signal, and a solenoid is energized from the counter according to the solenoid driving signal. A central processing unit (CPU) reads the MIDI data from a digital data storage device, and selects the corresponding solenoid driving parameters from a look-up table stored in read only memory (ROM). The solenoid driving parameters are converted into a pulse width modulation (PWM) waveform by a driving circuit containing counters. The PWM signal is sent to the gate of a field effect transistor (FET) switch connected to the solenoid and the solenoid is energized by the FET according to the PWM signal.