Yamaha Corporation

Kenta Ohnishi

Yuji Takahashi

Jun Ishii

Shinji Sumino

Tadaharu Kato

Yoshiya Matsuo

Hiroyuki Murakami

Rokurouta Mantani

Masayuki Satomi

A sound producing apparatus includes: a plurality of sound producing members with differing oscillation frequencies; dampers each corresponding to a respective sound producing member and suppressing vibration by contacting the corresponding sound producing members; a damper operation mechanism that moves each damper, thereby controlling a state of contact of the damper with a corresponding sound producing members; a soundboard that undergoes sympathetic resonance with sound producing members; a vibrator that vibrates the soundboard; an acquisition unit configured to acquire an audio signal; a signal output unit configured to: generate a drive signal for driving the vibrator with a vibration corresponding to the acquired audio signal; and output the drive signal to the vibrator; and a damper control unit configured to drive the damper operation mechanism to change a state of contact between the sound producing members and their corresponding dampers, based on frequency distribution of acquired audio signal.

Sound producing apparatus, keyboard instrument, and sound production control method

An audio signal that is output from a sound source circuit () is caused to flow through a coil () in a transducer for vibrating a soundboard, and the vibration of the soundboard generates an acoustic signal. A microcomputer () calculates a temperature of the coil () with high accuracy by inputting an ambient temperature (Ta) detected by an ambient temperature sensor () and a voltage (V) applied to the coil () and executing computation based on a thermal equivalent circuit of an acoustic signal converter using the ambient temperature and the voltage that are input thereto, the computation including calculation of an amount of electric power consumed in the coil () using the input voltage.

Temperature measurement device and protective device for acoustic signal converter

An installation structure for an acoustic transducer configured to vibrate a vibrated body in a first direction so as to permit the vibrated body to generate sounds, wherein the acoustic transducer includes: a magnetic-path forming portion that forms a magnetic path; a vibrating unit configured to vibrate in the first direction; and a connecting unit connecting the vibrating unit and the vibrated body to transmit vibration of the vibrating unit to the vibrated body, wherein the magnetic-path forming portion has a through-hole penetrating therethrough in the first direction from a first opening to a second opening, the connecting unit passing through the through-hole, wherein the vibrating unit is disposed on a first-opening side of the magnetic-path forming portion and is fixed to the connecting unit on the first-opening side, and wherein the vibrated body is connected to the connecting unit on a second-opening side of the magnetic-path forming portion.

Installation structure for acoustic transducer and musical instrument

An installation structure for an acoustic transducer configured to vibrate a vibrated body in a first direction so as to permit the vibrated body to generate sounds, wherein the acoustic transducer includes: a magnetic-path forming portion that forms a magnetic path; and a vibrating portion configured to vibrate in the first direction with respect to the magnetic-path forming portion, and wherein an anchor is provided between the vibrating portion and the vibrated body such that the anchor is undetachably fixed to the vibrated body by bonding and such that the anchor is detachably fixed to the vibrating portion.

Installation structure for acoustic transducer, musical instrument, and installation method of acoustic transducer

An installation structure for an acoustic transducer that operates in accordance with an audio signal to thereby vibrating a vibrated body in a first direction for permitting the vibrated body to generate sounds, including: a magnetic-path forming portion fixedly disposed relative to a fixedly supporting portion; a movable unit having an electromagnetic coupling portion electromagnetically coupled to the magnetic-path forming portion and configured to vibrate in the first direction when the electromagnetic coupling portion is driven by the magnetic-path forming portion in response to a drive signal based on the audio signal; a connector fixed to the vibrated body and connecting the movable unit to the vibrated body for transmitting vibration of the movable unit to the vibrated body; and at least two restricting mechanisms fixedly disposed relative to the fixedly supporting portion for restricting a movement of the movable unit in a second direction intersecting the first direction.

Installation structure for acoustic transducer

An installation structure for an acoustic transducer that operates in accordance with an audio signal to vibrate a vibrated body in a first direction for permitting the vibrated body to generate sounds, including: a magnetic-path forming portion; a vibrating unit configured to vibrate in the first direction; a connecting member disposed between: a part of the vibrated body or a fixed portion fixed to the vibrated body; and the vibrating unit, for transmitting vibration of the vibrating unit to the vibrated body; a first joint portion that connects a first end portion of the connecting member to the vibrating unit for enabling the connecting member to be inclined with respect to an axis extending in the first direction; and a second joint portion that connects a second end portion of the connecting member to the fixed portion for enabling the connecting member to be inclined with respect to the axis.

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.

Soundboard acoustic transducer

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

Actuator for vibrating a sound board in a musical instrument and method for attaching same

An installation structure for an acoustic transducer for vibrating a vibrated body in a first direction includes a magnetic-path forming portion; a movable unit having an electromagnetic coupling portion and configured to vibrate in the first direction; an attachment portion which attaches the magnetic-path forming portion to a fixed portion; a connector connected to the vibrated body and connecting the movable unit to the vibrated body; and a displacement permitting mechanism configured to permit electromagnetic coupling between the magnetic-path forming portion and the electromagnetic coupling portion to be maintained and to permit the vibration of the movable unit to be transmitted to the vibrated body when the connector is displaced with respect to the fixed portion within a predetermined range in an intersecting direction that intersects the first direction. The displacement permitting mechanism is provided at at least one of the attachment portion, the movable unit, and the connector.

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.

Automatic player musical instrument, automatic playing system incorporated therein and overheat protector for automatic playing system

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.

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.

Keyboard musical instrument

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.

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Hamamatsu, Japan

Kenta Ohnishi