JP4254673B2 - Music generator - Google Patents

Description

  The present invention relates to a musical sound generating apparatus that generates musical sounds by a frequency modulation (FM) method.

  Conventionally, many musical tone generation apparatuses of this type have been developed and widely used in the fields of synthesizers, electronic organs, mobile phones and the like. This FM tone generator is composed of a modulator (modulation signal generator) and a carrier (main melody generator), and a time-varying LPF (low pass) so that a complex tone can be added to the generated tone. A filter) is provided.

By the way, the conventional FM-type musical tone generator has a time-varying LPF (reference numeral 2) on the modulator side as described in, for example, FIG. 14 of Patent Document 1 (this figure is reprinted in FIG. 7). Therefore, there is a problem that it is impossible to generate a complicated tone and various variations.
Japanese Patent Laid-Open No. 3-121499

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a musical tone generating apparatus capable of generating more complex timbres and various variations than the conventional one.

The present invention has been made to solve the above-described problems, and the invention according to claim 1 is a musical sound generating apparatus configured by combining a plurality of operators that generate musical sound signals, and each of the plurality of operators. Is a musical sound generating device characterized in that a time-varying low-pass filter whose characteristics change with time is inserted on the output side of the.
According to a second aspect of the present invention, there is provided a first operator that generates a modulation signal, a first time-varying low-pass filter that is inserted on the output side of the first operator, and the first time-varying low-pass filter. A second operator for generating a carrier signal frequency-modulated by the signal at the modulation signal input terminal, and a second time variation inserted at the output side of the second operator; A musical sound generating device comprising a low-pass filter.

  According to a third aspect of the present invention, there is provided a first operator that generates a modulation signal, a first time-varying low-pass filter that cuts a high-frequency component of the output of the first operator, an output of the first operator, and One of the outputs of the first time-varying low-pass filter is selected, a second operator that generates a carrier signal frequency-modulated by the selected signal, and a high-frequency component of the output of the second operator is cut A musical sound generating apparatus comprising: a second time-varying low-pass filter; and a selection unit that selects and outputs one of the output of the second operator and the output of the second time-varying low-pass filter. is there.

  According to a fourth aspect of the present invention, a first operator that generates a modulation signal, one of the output of the first operator and the output of the time-varying low-pass filter is selected, and the carrier signal is frequency-modulated by the selected signal. A time-variable low-pass filter that selects and outputs one of the output of the first operator and the output of the second operator, and cuts and outputs the high-frequency component of the selected signal; And a selection means for selecting and outputting one of the output of the second operator and the output of the time-varying low-pass filter.

  According to the present invention, it is possible to generate more complex timbres and various variations than the conventional ones.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a musical sound generating apparatus according to the first embodiment of the present invention. In this figure, reference numeral 1 denotes an operator (musical sound signal generator) operating as a modulator, 2 denotes a time variation LPF, and 3 denotes a selector that selects and outputs one of the output of the operator 1 and the time variation LPF2. An operator 4 operates as a carrier, and the output of the selector 3 is applied to the modulation signal input terminal. Reference numeral 5 denotes a time fluctuation LPF inserted on the output side of the operator 4, and 6 denotes a selector for selecting and outputting one of the output of the operator 4 and the output of the time fluctuation LPF 5.

  FIG. 2 is a block diagram showing the configuration of operators 1 and 4. In this figure, 11 is a modulation signal input terminal to which a modulation signal (digital signal) is input, 12 is a multiplier, and 13 is switched by a feedback control signal FBC. The selector to be controlled. A phase generator 14 generates a sawtooth wave (digital signal) having a period corresponding to the pitch parameter PP, and outputs it to the adder 15 as phase data. The adder 15 adds the output of the selector 13 and the output of the phase generator 14 and outputs the result to the address generator 16. The address generator 16 adds an offset address determined according to the waveform parameter WP to the output of the adder 15 and outputs the addition result to the wave table 17 as address data.

  The wave table 17 is a table (ROM) in which one cycle of each waveform such as a sine wave, a triangular wave, and a rectangular wave is stored as digital data. The internal waveform data is read by the address data output from the address generator 16. And output to the multiplier 18. The envelope generator 19 generates an envelope signal determined according to the envelope parameter EP and outputs the envelope signal to the multiplier 18. The multiplier 18 multiplies the output of the wave table 17 by the output of the envelope generator 19 and outputs the multiplication result to the output terminal 20 and the input terminal of the multiplier 12.

  In such a configuration, when phase data is output from the phase generator 14 and supplied to the address generator 16 via the adder 15, the address data is output from the address generator 16 to the wave table 17. As a result, the waveform data is read from the wave table 17, and an envelope is added to the waveform data in the multiplier 18 and output from the output terminal 20. When the feedback control signal FBC is “0”, the selector 13 outputs the output of the multiplier 12, that is, the data obtained by multiplying the waveform data of the output terminal 20 by a certain number, and supplies it to the adder 15. Thereby, phase modulation is applied to the output signal of the output terminal 20 by the waveform data of the output terminal 20. When the feedback control signal FBC is “1”, the signal at the modulation signal input terminal 11 is output from the selector 13 and supplied to the adder 15. Thereby, phase modulation is applied to the output signal of the output terminal 20 by the signal of the modulation signal input terminal 11.

  FIG. 3 is a block diagram showing the configuration of the time varying LPFs 2 and 5. In this figure, 30 is an input terminal and 31 is an adder. The adder 31 adds the signal (digital signal) at the input terminal 30 and the output of the multiplier 32 and outputs the addition result to the adder 33. The adder 33 adds the output of the adder 31 and the output of the delay circuit 34 and outputs the addition result to the multiplier 35. The multiplier 35 multiplies the output of the adder 33 by the filter coefficient supplied from the filter envelope generator 36 and outputs the result to the adder 37. The adder 37 adds the output of the multiplier 35 and the output of the delay circuit 38 and outputs the addition result to the delay circuit 38 and the multiplier 39.

  The delay circuit 38 delays the output of the adder 37 by one cycle of the clock pulse and outputs it to the adder 37 and the multiplier 32. The multiplier 32 is a resonance setting multiplier, and its output is supplied to the adder 31 described above. The multiplier 39 multiplies the output of the adder 37 by the filter coefficient supplied from the filter envelope generator 36 and outputs the result to the adder 40. Adder 40 adds the output of multiplier 39 and the output of delay circuit 34, and outputs the addition result to delay circuit 34 and output terminal 41. The delay circuit 34 delays the output of the adder 40 by one cycle of the clock pulse and outputs it to the adder 33 and the adder 40.

The above-described configuration is a known digital LPF. In particular, the above circuit is configured as a time-varying LPF whose filter characteristics change with time. That is, the following parameters are set in advance in the filter envelope generator 36 by an external control circuit.
Fc0 to Fc4
FcOFFSET (Fc offset)
FAR (Filter Attack Rate)
FDR (filter decay rate)
FSR (Filter Sustain Rate)
FRR (filter release rate)

As shown in FIG. 4, when a key on signal is supplied from the control circuit to the filter envelope generator 36, the filter envelope generator 36 first sets the cutoff frequency Fc of the time variation LPF2.
Fc0 + FcOFFSET
Thereafter, the cut-off frequency Fc is successively increased at the FAR rate. And the cutoff frequency Fc is
Fc1 + FcOFFSET
Thereafter, the cutoff frequency Fc is successively attenuated at the FDR rate, and the cutoff frequency Fc is
Fc2 + FcOFFSET
Thereafter, the cutoff frequency Fc is successively increased at the rate of FSR so that the cutoff frequency Fc is
Fc3 + FcOFFSET
After that, the cutoff frequency Fc is held in that state. When the KeyOn signal is turned off, the cutoff frequency Fc is changed at the FRR rate thereafter.
Fc4 + FcOFFSET
Decrease until it reaches

In the musical sound generating apparatus shown in FIG. 1, the time fluctuation LPFs 2 and 5 described above are provided on the output side of the operator 1 and the output side of the operator 4, respectively. LPFs 2 and 5 can be inserted or not inserted into the outputs of operators 1 and 4. The musical sound generating apparatus can generate various musical sounds that are not conventionally provided by the selection functions of the selectors 3 and 6 and the functions of the time-varying LPFs 2 and 5.
It should be noted that only one operator 1, 4 or time variation LPF 2, 5 may be provided in hardware and used in a time-sharing manner. Moreover, you may implement | achieve them with DSP or CPU and software.

Next, a second embodiment of the present invention will be described with reference to FIG.
In FIG. 5, reference numeral 50 denotes an operator that functions as a modulator. SL1 is a selector that selects one of the output of the operator 50 and the output of the time-varying LPF 52 and outputs it to the modulation signal input terminal of the operator 51. The operator 51 is an operator that functions as a carrier. SL2 is a selector that selects one of the output of the operator 51 and the output of the operator 50 and outputs it to the time-varying LPF 52. SL3 is a selector that selects and outputs one of the output of the operator 51 and the output of the time-varying LPF 52. Here, the operators 50 and 51 have the configuration shown in FIG. 2, and the time-varying LPF 52 has the configuration shown in FIG.

The tone generator according to this embodiment does not use the time-varying LPF 52 inserted on the output side of the operator 50 or inserted on the output side of the operator 51 by switching the selectors SL1 to SL3 as shown in FIG. State. That is, when “1” is added as a selection signal to the selectors SL1 and SL2 and “0” is added as a selection signal to the selector SL3, the output of the operator 50 is applied to the time-varying LPF 52 through the selector SL2, and the output of the time-varying LPF 52 is The signal is applied to the input terminal of the operator 51 through the selector SL1, and the output of the operator 51 is output to the next stage through the selector SL3. When “0” is added as a selection signal to the selectors SL1 and SL2 and “1” is added as a selection signal to the selector SL3, the output of the operator 50 is applied to the operator 51 through the selector SL1, and the output of the operator 51 is output to the selector SL2. Is added to the time variation LPF 52, and the output of the time variation LPF 52 is output to the next stage through the selector SL3. When “0” is added as a selection signal to the electors SL1 and SL3, the output of the operator 50 is applied to the operator 51 through the selector SL1, and the output of the operator 51 is output to the next stage through the selector SL3.
Note that only one operator 50, 51 may be used in a time-sharing manner in terms of hardware. Further, the operators 50 and 51 and the time division LPF 52 may be realized by a DSP or a CPU and software.

  The present invention is used for electronic musical instruments, mobile phones, and the like.

It is a block diagram which shows the structure of the musical sound production | generation apparatus by 1st Embodiment of this invention. It is a block diagram which shows the structure of the operators 1 and 4 in FIG. It is a block diagram which shows the structure of the time variation LPF in FIG. It is a figure for demonstrating the characteristic of simultaneous fluctuation LPF. It is a block diagram which shows the structure of the musical sound production | generation apparatus by 2nd Embodiment of this invention. It is a figure for demonstrating the operation | movement of the embodiment. It is a block diagram which shows the structural example of the conventional musical sound production | generation apparatus.

Explanation of symbols

1, 4, 50, 51 ... operator, 2, 5, 52 ... time-varying low-pass filter, 3, 6, SL1-SL3 ... selector,

Claims (4)

A waveform table storing any one of a sine wave, a triangular wave, and a rectangular wave, and a plurality of sound signals are generated using any one of the sine wave, the triangular wave, and the rectangular wave read from the waveform table by address data A musical sound generator configured by combining operators ,
A musical sound generating device , wherein a time-varying low-pass filter whose characteristics change in accordance with a preset resonance and a time-varying cut-off frequency is inserted on each output side of the plurality of operators . A first operator that generates a modulated signal;
A first time-varying low-pass filter inserted on the output side of the first operator;
A second operator, wherein an output of the first time-varying low-pass filter is applied to a modulation signal input terminal, and a carrier signal frequency-modulated by the signal at the modulation signal input terminal is generated;
A second time-varying low-pass filter inserted on the output side of the second operator;
Equipped with,
The first operator and the second operator have a waveform table storing any one of a sine wave, a triangular wave, and a rectangular wave, and the sine wave, triangular wave, and rectangular wave read from the waveform table by address data To generate each signal using
The first time-varying low-pass filter and the second time-varying low-pass filter are:
A musical sound generating device characterized in that the characteristics change according to a preset resonance and a time-varying cut-off frequency. A first operator that generates a modulated signal;
A first time-varying low-pass filter that cuts a high-frequency component of the output of the first operator;
A second operator that selects one of the output of the first operator and the output of the first time-varying low-pass filter and generates a carrier signal that is frequency-modulated by the selected signal;
A second time-varying low-pass filter that cuts a high-frequency component of the output of the second operator;
Selecting means for selecting and outputting one of the output of the second operator and the output of the second time-varying low-pass filter;
Equipped with,
The first operator and the second operator have a waveform table storing any one of a sine wave, a triangular wave, and a rectangular wave, and the sine wave, triangular wave, and rectangular wave read from the waveform table by address data To generate each signal using
The first time-varying low-pass filter and the second time-varying low-pass filter are:
A musical sound generating device characterized in that the characteristics change according to a preset resonance and a time-varying cut-off frequency. A first operator that generates a modulated signal;
Selecting one of the output of the first operator and the output of the time-varying low-pass filter, and generating and outputting a carrier signal frequency-modulated by the selected signal;
Selecting one of the output of the first operator and the output of the second operator, cutting the high-frequency component of the selected signal, and outputting the time-varying low-pass filter;
Selecting means for selecting and outputting one of the output of the second operator and the output of the time-varying low-pass filter;
Equipped with,
The first operator and the second operator have a waveform table storing any one of a sine wave, a triangular wave, and a rectangular wave, and the sine wave, triangular wave, and rectangular wave read from the waveform table by address data To generate each signal using
The first time-varying low-pass filter and the second time-varying low-pass filter are:
A musical sound generating device characterized in that the characteristics change according to a preset resonance and a time-varying cut-off frequency.

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