Kabushiki Kaisha Kawai Gakki Seisakusho

Kawai Musical Inst. Mfg. Co., Ltd.

Kawai Musical Instruments Manufacturing Co., Ltd.

Kabushiki Kaisha Kawai Gakki

Kiyomi Takauji

Tatsunori Kondo

Mineo Kitamura

Yoichi Nagashima

Tadashi Matsushima

Eiji Nagashima

Masafumi Mizoguchi

Yutaka Washiyama

Sadaaki Ezawa

Seiji Kameyama

Hikaru Hashizume

Nobuharu Obayashi

Tohru Aoyama

An electronic musical instrument having a waveform memory of a relatively small capacity for storing waveform information similar to conventional waveform information, the waveform memory being compatible with any data reading scheme. The waveform information is stored in the form of a plurality of frames. Each frame includes a plurality of pieces of sampled waveform data compressed by ADPCM or the like and decode information for extending the sampled waveform data to be read next to the current frame. Storing the decode information in a frame for extending the sampled waveform data stored in frames before and after that frame makes it possible to extract the necessary decode information from the frame read immediately before regardless of whether the frames are read forward or backward.

Electronic musical instrument

An input data processor selects a value indicated by change border data, and uses this value as a reference value for determining whether a predetermined process is effected, and to change the currently used value indicated by the change border data to another value when the value of the input data becomes equal to a predetermined value. Namely, when the value of the input data is in the vicinity of a specific value, the detection of a change of the input data can be effected by using a resolution smaller than another resolution used for the detection when the value of the input data is not in the vicinity of the specific value. Detection of a change of the input data can be efficiently performed. Further, the apparatus for processing input data may convert the input data into conversion input data so that the rate of a change in the value of the conversion input data in the vicinity of a specific value of the input data is larger or smaller than that of a change in value of the conversion input data corresponding to other input data having values which are not in the vicinity of the specific value. Thus, when the value of the input data is equal to a specific value, the rate of a change of the input data is increased or decreased. Thus, small or large resolution, can be used when the input data becomes equal to the specific value.

Apparatus and a method for changing a resolution value of input musical

An electronic musical instrument such as a synthesizer includes a preset memory for storing, as preset data, a plurality of sets of parameters such as tone colors, tone volumes, pitches, special effects, and the like of tones to be generated. A designated parameter value in the preset data is increased/decreased to edit the preset data. When an edit mode is released, the edited preset data is automatically saved in a recall data memory. When a 'comparison' state is set during an edit operation, the preset data which is being edited is saved in the recall data memory, and preset data before editing or another preset data is set as tone generation data. When a 'recall' operation is performed, data in the recall data memory is read out as the latest preset data for tone generation. The edit operation is performed while confirming generated tones by alternately executing the 'comparison' and 'recall' operations.

Electronic musical instrument with a parameter storage for tone

A parameter signal generator including a parameter generating information storing unit for storing parameter generating information necessary for generating a parameter signal, and a parameter signal generating unit for generating a parameter signal. The parameter generating information is serially read from the parameter generating information storing unit and the thus-read parameter generating information is preset in a parameter signal generating unit other than the parameter generating information storing unit. Therefore, the parameter signal generator includes a storing unit other than the parameter signal generating unit, and accordingly, a general-use memory can be employed as the storing unit, to substantially lower cost. The processing of generating and radiating musical sounds can be performed at a practically required speed by employing a high speed processor as a central processing unit. Further, in the parameter signal generator, the length of time necessary for repeatedly generating a part or all of the parameter signal is measured, and when the measured length of time becomes equal to a predetermined length of time, the processing of repeatedly generating a part or all of the parameter signal is stopped. Accordingly, the length of time needed for repeatedly generating the parameter signal can be kept at a constant value, regardless of the pitches of musical sounds to be radiated, and thus, the inclusion in a musical sound radiated by the electronic musical instrument of an unnecessary changing factor, in response to the change of the pitch thereof, can be prevented.

Waveform signal generator

A device for changing and controlling the rate of generating waveform data wherein rate changing data such as phase angle step data corresponding to steps, wherein each pair of contiguous steps has an interval smaller than a preset interval, are necessary. The necessary rate changing data of interval other than the preset rate changing data is obtained by effecting an interpolation from the preset rate changing data. Accordingly, it becomes unnecessary to store the rate changing data obtained by performing the interpolation, and thus, the quantity of the phase angle step data SD to the stored can be greatly reduced.

Device for changing and controlling the rate of generating waveform data

An envelope generator for use in an electronic musical instrument comprises a musical tone data processing unit to evaluate a rate of change in a current value of musical tone envelope data with respect to a target value based on a parameter, a changing rate control unit for decrementing a change in the current value such that the current value becomes closer to the target value, a detection unit to detect whether or not the rate of change becomes equal to 0, and a processing control unit control for stopping the evaluation the current value in response to a result of the detection.

Envelope generator for use in an electronic musical instrument

An electronic musical instrument includes a decimal point position converting device for dividing an address corresponding to key information into an integer portion address and a decimal point portion address, the integer portion address being readout and sent to a waveform data memory as a read address, wherein a bit number of the address for access to the waveform data memory is changed correspondingly to a respective musical sound generators. An address control circuit converts the address corresponding to the key information into an address format in a location of the waveform data memory in which the desired waveform data is stored, and a data format converter circuit converts a data format of the desired waveform data readout from the waveform data memory so that the data readout from the waveform data memory is converted correspondingly to a respective one of the musical sound generators. A status memory stores control data for controlling operations of the decimal point position converting circuit, the address control circuit and the data format converter circuit.

Electronic musical instrument having waveform memory

A method of scaling a harmonic coefficient is employed, and envelope smaller in number than the number of harmonic orders are produced. One of the envelope is selected for each harmonic order and output as a scaling value. This enables the production of a musical tone imitative of a desired one, decreases the number of envelope generators needed, and permits simplification of the entire system configuration and signal processing.

Scaling of each harmonic coefficient for electronic musical instrument

An electronic musical instrument having a number of keys, having tone generators capable of simultaneous tone production, the tone generators being smaller in number than the number of keys. The instrument forms an operation for synthesizing a desired waveform, the operation for synthesizing a desired waveform being performed in a repeating cyclic order with an operation cycle and in which the waveform is transferred to the tone generators and read out therefrom at a rate in accordance with the note of a key being depressed to obtain a desired musical waveform. The device includes a number-of-depressed keys detecting device which counts the number of keys which are actuating the tone generator upon depression. A cycle altering device is provided for changing the operation cycle, as a whole, on the basis of the number of depressed keys, counted by the number-of-depressed keys detecting device. The construction allows for a waveform of a smooth temporal variation to be produced.

Optimization of waveform operation in electronic musical instrument

In the production of a desired musical waveform by combining harmonic components corresponding to respective harmonic orders, each harmonic component value is controlled by a selected cut-off harmonic order qc, level Ha and slope of the formant filter characteristic. The cut-off harmonic order qc, the level Ha and the slope values can each be varied over a predetermined range. Therefore, the slope values of the formant filter characteristic are interpolated to raise resolution, by which it is possible to prevent an abrupt change in the formant filter characteristic and suppress the generation of noise.

Formant filter generator for an electronic musical instrument

In the production of a desired musical waveform by combining harmonic components corresponding to respective harmonic orders, the cut-off harmonic order q.sub.c, each harmonic component value is controlled by selecting the level Ha and the slope of the Formant filter characteristic. The cut-off harmonic order q.sub.c, the level Ha and the slope value can each be varied over a predetermined range. These operations can be performed with a simple circuit arrangement involving a small number of memories. Therefore, the present invention greatly contributes to the reduction of the size and the cost of electronic musical instruments.

An electronic musical instrument is provided with a temporal variation circuit of SCF parameters for temporally varying the filter characteristic of a switched capacitor filter circuit, a control circuit for digitally controlling the temporal variation circuit and a touch response circuit for detecting, by scanning, touch response data in performance, whereby temporal variations of a musical waveform signal are digitally controlled.

In an electronic musical instrument which generates a musical waveform by calculating the waveform amplitude value at each sample point through Fourier synthesis, temporal variations of the musical waveform and its timbre variations in accordance with a touch response are controlled with respect to readout addresses for reading out a set of harmonic coefficient data for the Fourier synthesis from a memory having stored therein a plurality of sets of such harmonic coefficient data, thereby changing the component ratio of a harmonic coefficient which will ultimately be used as a Fourier coefficient.

Electronic musical instrument with temporal variation data generating

In an electronic musical instrument which generates a musical waveform by calculating the waveform amplitude value at each sample point through Fourier synthesis, note-range variations of the musical waveform and its timbre variations in accordance with a touch response are controlled with respect to readout addresses for reading out a set of harmonic coefficient data for the Fourier synthesis from a memory having stored therein a plurality of sets of such harmonic coefficient data, thereby changing the component ratio of a harmonic coefficient which will ultimately be used as a Fourier coefficient.

Electronical musical instrument with note frequency data setting circuit

In an electronic musical instrument, note frequency data corresponding to a plurality of temperaments are prestored and are selectively read out in accordance with a selected one of the temperaments, generating a note frequency corresponding thereto. Further, a plurality of note frequency data corresponding to each transposition operation for each temperament and selectively read out in accordance with a selected temperament and the transposition operation, thereby generating a note frequency corresponding thereto. Thus the temperament selection and the transposition operation can be performed with satisfactory stability and high frequency accuracy.

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Hamamatsu, Japan

Kiyomi Takauji