Kabushiki Kaisha Kawai Gakki Seisakusho

Tetsuya Hirano

Kenichi Hirota

Seiji Okamoto

Eiji Matsuda

Hisamitsu Honda

A musical tone generating device includes: a nonvolatile storage device that stores musical tone waveform data; a volatile storage device; and a control means that, when a power supply is turned on, performs control to transfer musical tone waveform data to the volatile storage device from the nonvolatile storage device, in the case where an instruction to reproduce a musical tone is given, the control means to read musical tone waveform data from the volatile storage device, and in the case where an error in the read musical tone waveform data is detected, the control means to perform control to overwrite musical tone waveform data obtained by correcting the musical tone waveform data including the detected error to the volatile storage device or transfer normal musical tone waveform data corresponding to the musical tone waveform data including the detected error to the volatile storage device from the nonvolatile storage device.

Musical tone generating device and control method of musical tone generating device

A digital signal processing device includes: a delay means that delays audio data in units of sampling periods; and a control means that writes audio data to a first buffer memory one word at a time in sequence at a sampling period, performs control to burst transfer burst length audio data to a DRAM from the first buffer memory, performs control to burst transfer the burst length audio data to a second buffer memory from the DRAM, and outputs audio data to the delay means from the second buffer memory one word at a time in sequence at the sampling period, in which a delay time of audio data output by the delay means is determined by a combination of a delay time of multiple sampling period units depending on a burst length of the DRAM and a delay time of a sampling period unit of the delay means.

Digital signal processing device and control method of digital signal processing device

A musical tone control system for a grand-type piano, which not only enables a shutter to be mounted on a hammer without any inconvenience even when a space above the hammer is small, but also is capable of properly controlling musical tones to be sounded. In this system, first to third optical sensors are disposed along the length of a hammer shank. Depression or non-depress of a key and a pivoting direction of an associated hammer are determined based on signals from the first and second optical sensors, respectively. Further, the pivoting speed of the hammer is calculated based on a signal from the third optical sensor. A musical tone to be sounded is controlled based on the determined depression or non-depression of the key and pivoting direction and the calculated speed of the hammer.

Musical tone control system for grand-type piano

There is provided a touch detecting device of a keyboard instrument, which makes it possible not only to enhance the mounting density of a plurality of optical sensors, but also to detect touch information of a key with high accuracy without being affected by light from the other optical sensors. The touch detecting device comprises a shutterthat moves in accordance with pivotal motion of a key, a plurality of optical sensorsandthat are provided close to a pivotal path of the shutterand have respective light emitting partsandand respective light receiving partsandfor receiving light emitted from the light emitting parts, on respective opposite sides of the pivotal path, and touch information detecting meansfor detecting, as the keypivotally moves, the touch information based on presence or absence of light received by the light receiving parts of the optical sensorsandin accordance with opening or closing of optical paths of light from the light emitting parts of the optical sensorsand, by the shutter. Adjacent two of the optical sensorsandare arranged such that the light emitting part of one of the two and the light receiving part of the other of the two disposed adjacent to each other on the same side of the pivotal path of the shutter

Touch detecting device of keyboard instrument

A data processor that allows a CPU to access an external memory in an interval between data accesses from a DSP having a variable data length. In a case where a 24-bit mode is set, when a determination section determines that the DSP is accessing the external memory, a control section commands to place an access from the CPU to the external memory in a wait state. In a case where a 16-bit mode is set, the control section commands an address-data switching section, allowing the CPU to access the external memory by utilizing a third bus cycle, which is free.

Device for processing access concurrence to shared memory

A sound control apparatus for a keyboard-based musical instrument for avoiding a touch of a shutter to a back check, thereby appropriately setting a sound generation timing and maintaining a satisfactory touch feeling. The sound control apparatus comprises a shutter integrated with a hammer adapted to swing associated with a swinging motion of a key, extending along a plane including a path along which said hammer swings, and formed with a cutout in an edge on an opposite side to a direction in which said hammer swings. An optical sensor has a light emitter disposed on one side of the swinging path of said shutter for emitting light, and a light receiver disposed on the other side of the swinging path for receiving the light from said light emitter, and generates a detection signal in accordance with a light receiving state of said light receiver. A CPU sets a sound generation timing at which music sound should be generated based on the detection signal of said optical sensor responsive to opening and closing of a light path of the light from said light emitter of said optical sensor by said shutter, when said hammer swings.

Sound control apparatus for a keyboard-based musical instrument

A speed detecting apparatus for a keyboard musical instrument is provided for accurately detecting the speed of bivotal movements of a hammer and a key even if a shutter implies errors in its attachment, without affected by such errors. The speed detecting apparatus for a keyboard musical instrument comprises a pivotable key, a hammer pivotably supported by a fulcrum and configured to pivotally move in association with a pivotal movement of the key, a shutter integrally attached to the hammer, a plurality of detectors, each having a light emitter and a light receiver for receiving light emitted from the light emitter, arranged on one and the other sides of the pivotal movement path of the shutter, and a CPU for detecting a pivot speed of the hammer in response to timings at which the shutter opens and closes the light paths of the light of the plurality of detectors when the hammer pivotally moves. The plurality of detectors have detection points on respective light paths of the light from the light emitters, and are arranged such that the detection points are positioned on an arc centered at the fulcrum of the hammer.

Speed detecting apparatus for keyboard musical instrument

A musical tone generating apparatus, which is capable of effectively utilizing the access timing for an unused slave sound source, is provided. The musical tone generating apparatus is composed of a master sound source, which comprises a mode switching means, an accumulator, an upper-address processing means, an address memory for a second sound source, an address-switching output means, a waveform data register, a sample buffer, an interpolation coefficient memory, an interpolation coefficient extracting means, a sample interpolation meansand a selection means

Musical sound generation device capable of effectively utilizing the access timing for an unused slave sound source

A electronic keyboard instrument for producing an artificial sound, including a plurality of keys; waveform-forming structure for generating a signal indicative of a waveform of an artificial sound corresponding to one of the keys, when the one of the keys is depressed; at least one operating element; detecting structure for detecting whether or not the at least one operating element is being operated; and waveform-modifying structure for modifying the signal indicative of the wave form depending on results of detection by the detecting structure, the waveform-modifying structure including envelope-determining structure for determining an envelope of the wave form of the artificial sound, and envelope-modifying structure for outputting a modification value used in changing an output from the envelope-determining structure depending on results of detection by the detecting structure.

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Hamamatsu, Japan

Tetsuya Hirano