Abstract: A musical instrument, including: an acoustic portion configured to generate sounds in accordance with a vibration; a plurality of soundboard braces attached to a flat surface of the acoustic portion; a bracket supported by two of the plurality of soundboard braces; and an acoustic transducer supported by the bracket and configured to vibrate the acoustic portion based on an acoustic signal inputted thereto, wherein the bracket is disposed so as to bridge the two of the plurality of soundboard braces, and the acoustic transducer vibrates the acoustic portion at a position between the two of the plurality of soundboard braces.

Abstract: A musical instrument, including: an acoustic portion configured to generate sounds in accordance with a vibration; a plurality of soundboard braces attached to a flat surface of the acoustic portion; a bracket supported by two of the plurality of soundboard braces; and an acoustic transducer supported by the bracket and configured to vibrate the acoustic portion based on an acoustic signal inputted thereto, wherein the bracket is disposed so as to bridge the two of the plurality of soundboard braces, and the acoustic transducer vibrates the acoustic portion at a position between the two of the plurality of soundboard braces.

Abstract: Provided is a keyboard musical instrument such as an acoustic piano or an electronic piano having an appearance and design similar to an acoustic piano, in which a fall board is made of a resin plate-shaped body, and hollow portions are provided inside the plate-shaped body. In addition, the plate-shaped body includes a plate-shaped resin foamed plate portion, and the hollow portions are made of plural air bubbles contained inside the resin foamed plate portion.

Abstract: An installation structure for an acoustic transducer configured to push and pull a vibrated body and having a magnetic-path forming portion; a vibrating unit; and a connector having at least one joint portion configured to connect two members such that axes of the two members are inclined relative to each other by bending at the at least one joint portion, the at least one joint portion having an urging portion configured to generate an urging force by which a pushing-side driving portion of a first member connected to one side of the at least one joint portion urges a pushing-side driven portion of a second member connected on another side of the at least one joint portion in a pushing direction and an urging force by which a pulling-side driving portion of the first member urges a pulling-side driven portion of the second member in a pulling direction.

Abstract: An installation structure for an acoustic transducer configured to push and pull a vibrated body and having a magnetic-path forming portion; a vibrating unit; and a connector having at least one joint portion configured to connect two members such that axes of the two members are inclined relative to each other by bending at the at least one joint portion, the at least one joint portion having an urging portion configured to generate an urging force by which a pushing-side driving portion of a first member connected to one side of the at least one joint portion urges a pushing-side driven portion of a second member connected on another side of the at least one joint portion in a pushing direction and an urging force by which a pulling-side driving portion of the first member urges a pulling-side driven portion of the second member in a pulling direction.

Abstract: Provided is a keyboard musical instrument such as an acoustic piano or an electronic piano having an appearance and design similar to an acoustic piano, in which a fall board is made of a resin plate-shaped body, and hollow portions are provided inside the plate-shaped body. In addition, the plate-shaped body includes a plate-shaped resin foamed plate portion, and the hollow portions are made of plural air bubbles contained inside the resin foamed plate portion.

Abstract: An optical modulator is hung from a key moved on a key trajectory so as to be moved together with the key, and a light beam, which is stationary with respect to a key bed, is radiated through the optical modulator; a large number of miniature refractors are formed on the light output surface of the optical modulator, and the density of miniature refractors per unit area is varied in a direction in which the optical modulator is moved together with the key so that the current key position is converted to the amount of light passing through the optical modulator; since the miniature refractors and other portions of optical modulator have a unitary structure, a molding process is used for the optical modulator, and the molding process make the production cost low.

Abstract: A hybrid keyboard musical instrument is fabricated on a piano, and a hammer stopper and an electronic tone generating system are installed in the piano; the electronic tone generating system includes hammer sensors arranged on a framework secured to a shank flange rail by means of stud bolts, and the stud bolts and spacer nuts, which are threaded with the stud bolts, serve as locators for locating the sensors at target relative positions with respect to the hammers independently in the fore-and-aft direction and up-and-down direction; the framework is pressed to the spacer nuts with nuts driven into the stud bolts so that the framework is removable from and reassembled with the shank flange rail without loosening the stud bolts.

Abstract: An optical modulator is hung from a key moved on a key trajectory so as to be moved together with the key, and a light beam, which is stationary with respect to a key bed, is radiated through the optical modulator; a large number of miniature refractors are formed on the light output surface of the optical modulator, and the density of miniature refractors per unit area is varied in a direction in which the optical modulator is moved together with the key so that the current key position is converted to the amount of light passing through the optical modulator; since the miniature refractors and other portions of optical modulator have a unitary structure, a molding process is used for the optical modulator, and the molding process make the production cost low.

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 electronic piano is controllable with a remote controller; since the remote controller is physically separated from the electronic piano, users are liable to mislay the remote controller somewhere around the electronic piano; in this situation, the user instructs the electronic piano to transmit a radio wave representative of inquiry, and the missing remote controller responds to the inquiry by transmitting a radio wave representative of annunciation; the electronic piano is equipped with antennas separated from each other on the piano cabinet, and the received power at the antennas is varied depending upon the location of the missing remote controller; the electronic piano analyzes the received power so as to notify the user of the possible location of the missing remote controller.

Abstract: An optical transducer includes a light emitting unit, a light detecting unit, light radiating sensor heads and light receiving sensor heads; the light radiating sensor heads and light receiving sensor heads are alternately arranged at intervals, and moving objects pass through the intervals in such a manner as to intersect light beams between the sensor heads; since the light emitting unit and light detecting unit are remote from the sensor heads, the light emitting unit and light detecting units are optically coupled to the sensor heads through optical fibers; a bundle of optical fibers is clipped on a predetermined route, and the optical fibers swerve from predetermined points of the bundle so that the optical fibers are surely warped so as to exert the resilient force on the inner surfaces of the optical devices, thereby being kept stable during the adhesion therebetween.

Abstract: An optical transducer includes a photo-electric converter supported by a shank flange rail and optical modulators respectively attached to hammers of an automatic player piano; since a neck portion makes a photo-modulating pattern closer to the rotational axis of each hammer than a boss portion adhered to the side surface of the hammer shank, the photo-modulating pattern is rotated in a narrow space in the vicinity of the rotational axis so as to permit the photo-electric converter to monitor the hammer motion between the rest position and the end position without any interference with other component parts, and the boss portion is easily adhered to the side surface under the condition that a worker lifts the hammer over the adjacent hammers.

Abstract: A light emitting device includes an optical fiber plug formed with a through-hole into which a bundle of optical fibers is inserted and a light-emitting device holder formed with a through-hole in which a condenser lens and a light emitting device are accommodated, and the optical fiber plug is assembled with the light-emitting device holder so that the light emitting device is optically coupled to the optical fiber through the condenser lens; a positioning device, a hyperboloid lens surface or a reflecting surface is formed in the optical fiber plug/light emitting device holder, condenser lens or the inner surface of the light-emitting device holder so that the light incident on the light input end is increased by virtue of the exact positioning between the optical fiber and optical axis, reduction of aberration or increase of light directed to the condenser lens.

Abstract: An optical transducer includes a multi-port light emitting unit for distributing sensing light to minor bundles of optical fibers connected to input ports thereof and a multi-port light detecting unit for converting the sensing light to photo-current; an optical fiber plug, a socket and light detecting elements received in the socket are assembled in the multi-port light detecting unit; the optical fiber plug is made of semi-transparent colored synthetic resin, which is transparent to short-wavelength light and non-transparent to long-wavelength light, so that the minor bundles are adhered to the optical fiber plug through adhesive compound cured in the radiation of the short-wavelength light; the long-wavelength light serves as the sensing light so that leakage light does not reach the adjacent input ports.

Abstract: An optical position transducer is provided for each of the black/white keys incorporated in a composite keyboard musical instrument; the optical position transducer includes a photo-coupler radiating a light beam, an optical filter moved across the light beam, a recess formed in the black/white key at a proper position where the optical filter is aligned with a target trajectory crossing the light beam and an elastic coupler pressed to an inner surface defining the recess and secured to the optical filter so that a worker assembles the optical filter with the key by inserting the elastic coupler into the recess.

Abstract: An optical sensor array includes light-emitting devices and sensor heads remote from the light-emitting devices, and each light-emitting device is optically coupled to plural sensor heads through optical fibers; the light-emitting device is optically connected to the optical fibers by means of a multicore optical fiber connector, and the multicore optical fiber connector keeps the optical axes of the optical fibers equally spaced from the optical axis of the light-emitting device; even though the light intensity is isotropically dispersed on the cross section of the light beam, the total amount of light incident on each optical fiber is equal to the total amount of light incident on any one of the other optical fibers so that a strict calibration is not required for the optical sensor array.

Abstract: A hybrid keyboard musical instrument is fabricated on a piano, and a hammer stopper and an electronic tone generating system are installed in the piano; the electronic tone generating system includes hammer sensors arranged on a framework secured to a shank flange rail by means of stud bolts, and the stud bolts and spacer nuts, which are threaded with the stud bolts, serve as locators for locating the sensors at target relative positions with respect to the hammers independently in the fore-and-aft direction and up-and-down direction; the framework is pressed to the spacer nuts with nuts driven into the stud bolts so that the framework is removable from and reassembled with the shank flange rail without loosening the stud bolts.

Abstract: A hammer sensor includes a photo-filter plate movable together with a hammer assembly and having a base plate fixed to the hammer shank and an arc pattern formed on the base plate and different in transparency from the base plate, a photo radiating element radiating a light beam toward the arc pattern and a photo detecting element disposed on the optical path of the light beam for converting the amount of transmitted light to an electric signal, wherein the photo-filter plate converts the rotational angle of the hammer assembly to the amount of light incident on the photo detecting element, and makes the photo radiating element and the photo detecting element stationary so that a suitable photo-shield case prevents the photo elements from environmental light.

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.