Abstract: A performance operator control apparatus adapted to a player piano comprises a motion control unit and a key drive unit comprising a plurality of key I/O control ICs in connection with keys of a keyboard, which are driven by solenoids so as to realize automatic performance, wherein upon detection of electrification abnormality of solenoids or temperature abnormality, LEDs are turned on to indicate the abnormality. The key I/O control ICs receive velocity signals regarding the solenoids so as to perform feedback controls on the keys in the automatic performance. In addition, unoccupied channels of the key I/O control ICs, which are not assigned to the keys and sensors, are used to input monitoring signals and to output inspection signals. Herein, the abnormality is determined based on the difference between pre-inspection data and post-inspection data, which are transferred using a loop connection channel of the key I/O control IC.

Abstract: Keys, which are incorporated in an automatic player piano, are monitored with an optical transducer system. The optical transducer system includes sensor heads provided on both sides of the key trajectories, LEDs connected to predetermined sensor heads through optical fibers, LDDs connected to the other sensor heads through optical fibers and a controlling unit. A luminescence controller is connected to the LEDs for optimizing the luminescence, and bias controllers are respectively connected to the LDDs. The luminescence controller and bias controllers optimize the luminescence of emitted light and the bias level of electric signals so that the optical transducer system is free from the individuality of component parts and the deterioration.

Abstract: An automatic player piano includes an acoustic piano and an electronic system for reenacting a performance on the acoustic piano; a self-diagnosis subroutine program runs on a microprocessor of the electronic system so as to diagnose solenoid-operated actuators with built-in plunger sensors and component parts of the acoustic piano such as keys, pedals, action units and hammers on the basis of pieces of plunger data, pieces of key data and pieces of hammer data; thus, the mechanical components of the piano are diagnosed as well as the electric components through the execution of the self-diagnosis subroutine program.

Abstract: An automatic player piano includes an acoustic piano and an electronic system for reenacting a performance on the acoustic piano; a self-diagnosis subroutine program runs on a microprocessor of the electronic system so as to diagnose solenoid-operated actuators with built-in plunger sensors and component parts of the acoustic piano such as keys, pedals, action units and hammers on the basis of pieces of plunger data, pieces of key data and pieces of hammer data; thus, the mechanical components of the piano are diagnosed as well as the electric components through the execution of the self-diagnosis subroutine program.

Abstract: An optical sensor system includes a light emitting unit, a light detecting unit, light radiating optical sensor heads connected through optical fibers to the light emitting unit and light receiving optical sensor heads connected through optical fibers to the light detecting unit, and light is selectively distributed to the light radiating optical sensor heads for radiating light beams from both side surfaces of each sensor head to the adjacent light receiving optical sensor heads for converting the incident light to photo-current; each light radiating optical sensor head has prisms for splitting the light into two beams; however, the stray light is produced at the edge between the reflection surfaces; the stray light is reduced or predictably controlled by forming textured pattern on the side surfaces, a photo-shield member or notches; otherwise, the edge is sharpened by separately forming the prisms.

Abstract: Keys, which are incorporated in an automatic player piano, are monitored with an optical transducer system; the optical transducer system includes sensor heads provided on both sides of the key trajectories, LEDs connected to predetermined sensor heads through optical fibers, LDDs connected to the other sensor heads through optical fibers and a controlling unit; a luminescence controller is connected to the LEDs for optimizing the luminescence, and bias controllers are respectively connected to the LDDs; the luminescence controller and bias controllers optimize the luminescence of emitted light and the bias level of electric signals so that the optical transducer system is free from the individuality of component parts and aged deterioration.

Abstract: A performance operator control apparatus adapted to a player piano comprises a motion control unit and a key drive unit comprising a plurality of key I/O control ICs in connection with keys of a keyboard, which are driven by solenoids so as to realize automatic performance, wherein upon detection of electrification abnormality of solenoids or temperature abnormality, LEDs are turned on to indicate the abnormality. The key I/O control ICs receive velocity signals regarding the solenoids so as to perform feedback controls on the keys in the automatic performance. In addition, unoccupied channels of the key I/O control ICs, which are not assigned to the keys and sensors, are used to input monitoring signals and to output inspection signals. Herein, the abnormality is determined based on the difference between pre-inspection data and post-inspection data, which are transferred using a loop connection channel of the key I/O control IC.

Abstract: An optical sensor system includes a light emitting unit, a light detecting unit, light radiating optical sensor heads connected through optical fibers to the light emitting unit and light receiving optical sensor heads connected through optical fibers to the light detecting unit, and light is selectively distributed to the light radiating optical sensor heads for radiating light beams from both side surfaces of each sensor head to the adjacent light receiving optical sensor heads for converting the incident light to photo-current; each light radiating optical sensor head has prisms for splitting the light into two beams; however, the stray light is produced at the edge between the reflection surfaces; the stray light is reduced or predictably controlled by forming textured pattern on the side surfaces, a photo-shield member or notches; otherwise, the edge is sharpened by separately forming the prisms.

Abstract: An electronic piano has only one set of analog key sensors/shutter plates under the keyboard, and an electronic sound generating system processes pieces of data information from the analog key sensors through different computer programs for an initial-touch and an after-touch so as to achieve a wide variety of sound control without increase of electric components.

Abstract: A keyboard musical instrument includes an acoustic piano for generating acoustic tones, a silent system for rebounding the hammer assemblies between the escape from the key action mechanisms and strikes against strings and automatic playing system for actuating the key action mechanisms without fingering, and the automatic playing system generates electronic tones on the basis of the key motions monitored by associated key sensors, wherein the space between the rest position and the end position is divided into plural sections, and a controller calculates a key velocity in each of the plural sections so as to exactly determine the key motion, thereby improving the fidelity of the electronic sounds to the key motion.

Abstract: An automatic player piano determines the loudness of an acoustic tone to be reproduced in a playback on the basis of a hammer velocity, and the hammer velocity is calculated on the basis of a long distance defined in a shutter plate attached to each of the hammers for a strongly depressed key or a short distance also defined in the shutter plate for a softly depressed key so as to accurately produce the acoustic tone.

Abstract: An automatic player piano has key sensors for producing digital key position signals representative of current key positions and a recording unit for producing pieces of music data information on the basis of the key motions; however, the key sensors have individualities, and vary the values of the digital key position signals in different ranges, respectively; the recording unit selects different components bits from each of the digital key position signal depending upon the value at a reference point so as to make the difference between the ranges small.

Abstract: An automatic player piano is equipped with a position detecting device for detecting current positions of the black/white keys, and the position detecting device radiates light beams across the trajectories of the black/white keys, wherein the position detecting device stores a variable relation between a relative value of the amount of light and the current positions for determining the current positions so that the position detecting device keeps the reliability of the current positions against aged deterioration.

Abstract: A keyboard musical instrument continuously monitors a key motion, and determines present key state on the basis of the previous key state, the present key position and a lapse of time during the previous key state so as to exactly control a tone generation.

Abstract: A keyboard musical instrument includes an acoustic piano for generating acoustic sounds, an electronic system for generating electronic sounds and a silent system for selecting one of the acoustic sounds and the electronic sounds, and the electronic system is equipped with key sensors and hammer sensors so as to determine a loudness of the electronic sound and a timing for a tone-generation from a key position signal or a hammer position signal depending upon a fingering on a keyboard.

Abstract: A hammer sensor of a keyboard musical instrument monitors a hammer action from a home position to a rebounding point on a stopper or strings, and a controller determines a hammer velocity and a time at an intermediate point on a trajectory of the hammer in a recording mode; the controller delays the time so as to determine a key-on timing, and an electronic system reproduce the acoustic or electronic sound at the key-on timing in a playback mode so as to reproduce the acoustic or electronic sound at the same timing as the original sound.

Abstract: A keyboard musical instrument produces electronic sounds in synchronism with fingering on a keyboard, and a player can select an reverberation emvironment and a depth of reverberation through predetermined keys of the keyboard before the performance, thereby making an arrangement on a switch board simpler.