JP3758664B2 - Musical sound signal generator - Google Patents

Description

  The present invention relates to a musical sound waveform signal generator suitable for various electronic devices such as an electronic musical instrument such as a digital synthesizer, a personal computer having a musical sound generation function, a game device, and a karaoke device.

  Conventionally, the VCO (Voltage Controlled Oscillator) of the slave unit of the analog synthesizer is reset by the VCO of the master unit, so that sounds having various overtone structures can be obtained depending on the pitch ratio of the master unit and the slave unit. The sync function in analog synthesizers is well known. Also, in the musical sound waveform signal generator that digitally generates a musical sound waveform signal, in order to realize the sink function, the accumulated frequency information is accumulated and changed in a cycle inversely proportional to the frequency information. A control waveform having a predetermined period by a control waveform signal generator in a musical sound waveform signal generator having accumulating means for outputting a value and generating a musical sound waveform signal based on an accumulated value by the accumulating means It is also conventionally known that the accumulated value of the accumulating means is set to a predetermined initial value for each cycle of the signal (see, for example, JP-A-10-198378).

  However, in the above-described conventional apparatus, musical tone waveform signals having various overtone structures can be obtained by changing the input frequency information, but the accumulated value of the accumulating means is obtained for each cycle of the control waveform signal. Since the value is always reset to a certain value, there is a limit to the tone waveform signal that can be obtained.

  The present invention has been made to address the above problems, and an object of the present invention is to provide a musical sound waveform signal generator capable of generating a musical sound waveform signal rich in change by changing a musical sound waveform signal in a complex manner. is there.

In order to achieve the above-mentioned object, the structural features of the present invention include an arithmetic unit that calculates input frequency information and a fed back accumulated value, and stores an arithmetic result calculated by the arithmetic unit. vessels to become a storage element for feeding back the accumulated values, and accumulating means for outputting the accumulated value by accumulating the frequency information input varies in a cycle which is inversely proportional to the frequency information, the control having a predetermined period A control waveform signal generating means for generating a waveform signal; a synchronizing means for setting an accumulated value of the accumulating means to a predetermined initial value in synchronization with a cycle of the control waveform signal; and a circulation path for the accumulated value. A conversion means for converting the accumulated value with a predetermined conversion characteristic is provided, and a musical sound waveform signal is generated based on the accumulated value.

  According to this, the accumulated value is converted according to the characteristics of the conversion means, and the musical sound waveform signal is generated according to the converted accumulated value, so that the musical sound waveform signal having a complicated and special effect is obtained. Is obtained.

  Hereinafter, each embodiment of the present invention will be described sequentially.

a. First Embodiment FIG. 1 is a block diagram showing a musical sound waveform signal generator according to a first embodiment of the present invention.

  This musical sound waveform signal generator comprises two systems of musical sound waveform signal generators comprising a master part MA and a slave part SL, and outputs musical sound waveform signals from the master part MA and slave part SL, respectively, and the slave part SL. Are synchronized with the musical tone waveform signal of the master unit MA, so that a frequency component (harmonic component) that is an integral multiple of the fundamental frequency of the musical tone waveform signal in the master unit MA and a frequency component lower than the fundamental frequency ( Subharmonic component).

  The master unit MA includes an adder 12 and a storage element 13 that constitute an accumulating unit for accumulating the master-side fundamental frequency information Fnm input from the first frequency information input terminal 11. The adder 12 is composed of a modulo type adder that truncates bits exceeding the valid bits in fixed-point arithmetic, performs an addition operation within the range of “0” to “1”, and the addition result exceeds “1”. And an overflow signal OF is output. The storage element 13 stores the output of the adder 12 and outputs the stored value delayed by one clock (one sample time). Thereby, as shown in FIG. 2, the accumulating means outputs a sawtooth wave signal Pm having a period inversely proportional to the magnitude of the frequency information Fnm and repeatedly changing from “0” to “1”. .

  The master unit MA also includes a waveform generation unit 14 connected to the output terminal of the adder 12. The waveform generator 14 outputs a first musical sound waveform signal SO1 having a frequency proportional to the frequency information Fnm to the first output terminal 15 based on the sawtooth wave signal (phase signal) Pm from the adder 12. For example, it comprises a waveform memory that stores waveform sample data for one period. Further, the waveform generator 14 is constituted by a sine wave memory for storing a sine waveform, or an FM sound source circuit (FM operator) for synthesizing the first musical sound waveform signal SO1 using the output signal from the adder 12 as a phase signal Pm. You may comprise.

  The slave unit SL also includes an accumulation unit including an adder 22 and a storage element 23 for accumulating the slave-side fundamental frequency information Fns input from the second frequency information input terminal 21, and a waveform generation unit 24. The adder 22, the storage element 23, and the waveform generation unit 24 are configured in the same manner as the adder 12, the storage element 13, and the waveform generation unit 14 of the master unit MA, and the second musical sound waveform signal SO2 generated from the waveform generation unit 24. Is supplied to the second output terminal 25. Also in the slave portion SL, the accumulating means comprising the adder 22 and the storage element 23 has a period inversely proportional to the magnitude of the frequency information Fns, as shown in FIG. A sawtooth wave signal (phase signal) Ps that changes over time is output.

  A switching circuit 26 is connected between the output terminal of the adder 22 and the input terminals of the storage element 23 and the waveform generator 24. The switching circuit 26 supplies the output signal from the adder 22 normally supplied to the first input terminal 26 a to the storage element 23 and the waveform generator 24, and the second input terminal 26 b when the reset signal is input from the reset circuit 27. Is supplied to the storage element 23 and the waveform generator 24. The reset circuit 27 detects the overflow signal OF from the master unit MA and outputs a reset signal to the switching circuit 26.

  The second input terminal 26b of the switching circuit 26 includes an initial value calculation circuit including a divider 31, a multiplier 32, and an adder 33, and an initial value correction circuit including multipliers 34, 35 and adders 36, 37. It is connected. The initial value calculation circuit is connected to the slave unit SL every time the sawtooth wave signal Pm by the accumulating means of the master unit MA changes from “1” to “0”, that is, every time a reset signal is output from the reset circuit 27. A value (predetermined initial value) at which the sawtooth wave signal Ps by the accumulation means is reset is calculated.

  The necessity of this initial value calculation circuit will be described. If the sampling frequency can be set extremely higher than the frequency of the musical sound waveform signal, or if the sampling frequency is an integral multiple of the frequency of the musical sound waveform signal by the master unit MA Absent. However, in practice, it is difficult to do so, and there is a time lag between the time when the sawtooth wave signal Pm of the master unit MA changes from “1” to “0” and the sampling timing. That is, the timing at which the accumulating means of the slave part SL is reset is delayed from the time when the sawtooth wave signal Pm by the accumulating means of the master part MA becomes “0”, and after the time when the accumulating means becomes “0”. Next sampling timing. Due to this shift, the tone waveform signal formed by the slave portion SL has a phase shift, that is, jitter, which differs from cycle to cycle with respect to the tone waveform signal formed by the master portion MA.

In order to correct such a deviation, a divider 31 and a multiplier 32 are provided. Next, the meaning of these divider 31 and multiplier 32 will be described. Sawtooth signal Pm by accumulating unit of the master unit MA is changed as shown in the upper part of FIG. 2, it changes from "1" to "0" in virtual time t _{1 '.} This is because sample values (illustrated by black circles) can take actual values only at sampling timings t ₀ , t ₁ , t ₂ . Now, it is assumed that the sawtooth wave signal value Pm of the master unit MA changes from “1” to “0” at the virtual time point t ₁ ′, and “0” of the sawtooth wave signal at the sampling timing t ₁ . The increment from “” is Pm1. On the other hand, when the sawtooth wave signal Ps of the slave SL is reset to a predetermined initial value (“0” in the present embodiment) at the virtual time point t ₁ ′, the sawtooth wave at the sampling timing t ₁ is assumed. The increment of the signal Ps from the initial value becomes Ps1. Since the ratio of the magnitudes of these increments Pm1 and Ps1 is equal to the ratio of the magnitudes of the frequency information Fnm and Fns input to the master unit MA and the slave unit SL, the following formula 1 is established.
Ps1 / Pm1 = Fns / Fnm Formula 1

By modifying Equation 1, the increase Ps1 on the slave unit SL side is given as Equation 2 below.
Ps1 = Pm1 · Fns / Fnm Equation 2

  The divider 31 divides the output value Pm1 from the adder 12 by the frequency information Fnm from the first frequency information input terminal 11, and outputs a division result Pm1 / Fnm. The multiplier 32 multiplies the output value Pm1 / Fnm of the divider 31 by the frequency information Fns from the second frequency information input terminal 21, and outputs a multiplication result Pm1 · Fns / Fnm. Thus, even if the sampling frequency is not extremely higher than the frequency of the musical sound waveform signal, even if the sampling frequency is not an integer multiple of the frequency of the musical sound waveform signal by the master unit MA, an initial value that does not cause jitter can be calculated. it can.

  The adder 33 is connected to the multiplier 32 and the offset information input terminal 41, and adds the offset value Pi supplied to the offset information input terminal 41 to the initial value calculated by the initial value calculation circuit, An initial value Po = Pm1 · Fns / Fnm + Pi including the offset value Pi is output.

  In the present embodiment, the initial value is calculated by the divider 31 and the multiplier 32. However, the sampling frequency is extremely higher than the frequency of the musical sound waveform signal, or the sampling frequency is that of the musical sound waveform signal by the master unit MA. When the frequency is an integer multiple or the occurrence of jitter is not a problem, the divider 31, multiplier 32 and adder 33 are not required, and the offset value Pi is directly input to the multiplier 34. do it. This corresponds to the predetermined initial value being “0”.

  Next, an initial value correction circuit composed of multipliers 34 and 35 and adders 36 and 37 will be described. The multiplier 34 multiplies the initial value Po from the adder 33 by the synchronization coefficient Hs supplied to the synchronization coefficient information input terminal 42, and outputs the multiplication result Hs · Po. The multiplier 35 multiplies the signal value Ps of the sawtooth wave signal (phase signal) by the accumulating means comprising the adder 22 and the storage element 23 by the synchronization coefficient Hs, and outputs the multiplication result Hs · Ps. The adders 36 and 37 substantially perform a subtraction operation. The adder 36 subtracts the output value Ps from the adder 22 from the output value Hs · Ps from the multiplier 35, and the subtraction result (Hs− 1) Output Ps. The adder 37 subtracts the output value (Hs−1) · Ps from the adder 36 from the output value Hs · Po from the multiplier 34 and outputs a subtraction result Hs · Po + (1−Hs) · Ps. . Thus, the initial value correcting circuit adds the sawtooth wave signal Ps of the accumulating means comprising the adder 22 and the storage element 23 to the initial value Po at a ratio corresponding to the synchronization coefficient Hs, that is, the initial value Po and the sawtooth. The waveform signal Ps is weighted and synthesized according to the synchronization coefficient Hs and is output to the second input terminal 26b of the switching circuit 26.

  Next, the operation of the first embodiment configured as described above will be described. In the master unit MA, the accumulating means composed of the adder 12 and the storage element 13 sequentially accumulates the master side fundamental frequency information Fnm inputted from the first frequency information input terminal 11, so that the upper part of FIG. As shown, a sawtooth wave signal Pm that repeatedly changes from “0” to “1” with a period inversely proportional to the frequency information Fnm is generated. Then, the waveform generator 14 outputs a first musical sound waveform signal SO1 corresponding to the function of the waveform generator 14 to the first output terminal 15 using the sawtooth wave signal Ps as phase information.

  On the other hand, also in the slave unit SL, the output of the adder 22 is normally connected to the storage element 23 via the first input terminal 26a of the switching circuit 26, and the accumulation means composed of the adder 22 and the storage element 23 includes: By sequentially accumulating the slave-side fundamental frequency information Fns input from the second frequency information input terminal 21, as shown in the lower part of FIG. 2, “0” to “1” with a period inversely proportional to the frequency information Fns. A sawtooth wave signal Ps that repeatedly changes over time is generated.

  For the sawtooth wave signal Ps, the sawtooth wave signal Pm which is the output of the accumulating means of the master unit MA acts as a control waveform signal for synchronous control. The reset circuit 27 supplies a reset signal to the switching circuit 26 every time the adder 12 generates the overflow signal OF, that is, every time the sawtooth signal Pm changes from “1” to “0”. As a result, the switching circuit 26 supplies the storage element 23 with the initial value that is switched and supplied to the second input terminal 26b, so that the accumulating means of the slave portion SL is reset at the timing of the reset signal. To the initial value. That is, the phase signal for the waveform generator 24 of the slave unit SL is reset for each period of the musical tone waveform signal SO1 of the master unit MA. Then, based on this phase-controlled phase control, the waveform generator 24 outputs a second musical sound waveform signal SO2 corresponding to the function of the waveform generator 24 to the second output terminal 25.

  Thereby, from the second output terminal 25, a rich second musical sound waveform signal having a frequency component of formant characteristics determined by the fundamental frequency Fs represented by the frequency information Fns and the fundamental frequency Fm represented by the frequency information Fnm. SO2 is output. The second musical sound waveform signal SO2 from the slave portion SL is mixed with the first musical sound waveform signal SO1 from the master portion MA, or is output alone as a musical sound.

  In the synchronous control in the accumulating means of the slave part SL, the divider 31 and the multiplier 32 calculate the initial value for the accumulating means of the slave part SL at the reset timing and are generated by the accumulating means. Since the phase shift associated with the reset of the sawtooth signal Ps is eliminated, the synchronization control is performed well and the sound quality of the generated musical tone is kept good.

  In the first embodiment, the initial value is corrected by the offset value Pi and the synchronization coefficient Hs given from the outside. The effect of this modification will be described with reference to FIGS. 3-7, the waveform generating unit 24 of the slave unit SL is configured by a sine wave memory, the sampling frequency is 44.1 KHz, the basic frequency on the master unit MA side is 440 Hz, the basic frequency on the slave unit SL side is 660 Hz, In the state where the offset value Pi is set to “0”, the sawtooth wave signal Pm on the master part MA side, the sawtooth wave signal Ps on the slave part SL side and the slave part SL when the synchronization coefficient Hs is variously changed. It is a wave form diagram which shows the time change of the output waveform signal SO2 of the 2nd output terminal 25 of the side. The numbers in the lower column of these waveform diagrams indicate the sample value numbers.

  3 and 4 show the cases where the synchronization coefficient Hs is set to “1.0” and “0.0”, respectively. In FIG. 3, the sawtooth signal Pm on the master unit MA side changes from “1” to “0”. At this time, the sawtooth wave signal Ps on the slave unit SL side is completely reset to “0”, and the sawtooth wave signal Ps and the output waveform signal SO2 are a musical sound waveform signal including a harmonic component having a complex harmonic structure. Become. In FIG. 4, even if the sawtooth wave signal Pm on the master unit MA side changes from “1” to “0”, the sawtooth wave signal Ps on the slave unit SL side is not reset at all. The signal Ps is maintained at a 660 Hz sawtooth wave, and at the same time, the output waveform signal SO2 is also maintained at a 660 Hz sine wave.

  On the other hand, FIGS. 5 to 7 show temporal changes of the sawtooth wave signals Pm, Ps and the output waveform signal SO2 when only the synchronization coefficient Hs is changed from “0.75”, “0.50” and “0.25” from the above state. Each is shown. According to this, it can be seen that as the synchronization coefficient Hs is decreased, the synchronization control on the slave unit SL side by the sawtooth signal Pm on the master unit MA side gradually becomes incomplete. Then, since the synchronization control is incomplete, a soft sync effect is realized, and a subharmonic component having a frequency lower than the frequency represented by the frequency information Fnm is generated according to the synchronization coefficient Hs. I understand that. As a result, by setting the synchronization coefficient Hs to an appropriate value between “0” and “1”, a complex musical sound waveform signal can be obtained and the analog synthesizer can be changed from hard sync to soft sync. . Further, by changing the synchronization coefficient Hs with time, it is possible to obtain a musical sound waveform signal that changes with time in a complicated manner.

  FIG. 8 shows the sawtooth wave signals Pm and Ps and the output waveform signal SO2 when only the offset value Pi of the various parameters is changed to “0.2” with the synchronization coefficient Hs set to “1.0”. It is a wave form diagram which shows a time change. This also shows that the output waveform signal SO2 changes from when the offset value Pi in FIG. 3 is set to “0”, and a complex musical sound waveform signal can be obtained.

b. Second Embodiment Next, a second embodiment of the present invention will be described. A musical tone waveform signal generator according to the second embodiment is shown in a block diagram in FIG.

  The musical tone waveform signal generator according to the second embodiment is characterized in that the synchronization control of the slave unit SL by the master unit MA of the first embodiment is conditioned, and the switching circuit provided in series with the switching circuit 26 51, and a master signal MA and a slave signal SL are provided with a random signal generator (random number generator) 52 as control signal generating means that changes with time independently. Note that the initial value correction circuit including the multipliers 34 and 35 and the adders 36 and 37 of the first embodiment may be left as they are, but is omitted in the second embodiment. Further, circuits having the same functions as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The switching circuit 26 has its first input end 26 a connected to the output end of the adder 22, its second input end 26 b directly connected to the output end of the adder 33, and its output end connected to the second end of the switching circuit 51. The input terminal 51 is connected. When the switching signal from the comparator 53 connected to the random signal generator 52 is at a low level, the switching circuit 51 uses the output signal of the adder 22 supplied to the first input terminal 51a as the storage element 23 and the waveform. Supply to the generator 24. When the switching signal is at a high level, the switching circuit 51 supplies the output signal supplied from the switching circuit 26 to the second input terminal 51 b to the storage element 23 and the waveform generator 24.

  The random signal generator 52 generates a random signal (random signal) that randomly changes between “0” and “1”. The comparator 53 compares the random signal value from the random signal generator 52 with the synchronization coefficient Hs from the synchronization coefficient information input terminal 42, and outputs a low level signal when the random signal value is larger than the value of the synchronization coefficient Hs. The high level signal is output to the switching circuit 51 when the random signal value is equal to or less than the synchronization coefficient Hs.

  In the second embodiment configured as described above, even if the sawtooth wave signal Pm of the master unit MA changes from “1” to “0” every period and a reset signal is given from the reset circuit 27, If the random signal value is larger than the synchronization coefficient Hs, the switching circuit 51 outputs the output signal of the adder 22 to the storage element 23 and the waveform without outputting the initial value output from the switching circuit 26 while maintaining the illustrated state. The supply to the generator 24 is continued. Only when the reset signal is given from the reset circuit 27 in a state where the random signal value is equal to or smaller than the synchronization coefficient Hs, the switching circuit 51 switches the initial value output from the switching circuit 26 from the illustrated state to the storage element. 23 and the waveform generator 24.

  Therefore, according to the second embodiment, the synchronization control by the master unit MA is permitted or prohibited according to a random signal (control signal) that varies with time independently of the waveform signals in the master unit MA and the slave unit SL. Will be selectively conditioned. As a result, the initial value setting (reset) of the initial value of the accumulating means composed of the adder 22 and the storage element 23 is performed or not performed according to the random signal, that is, the sync function is performed according to the random signal. Thus, a musical tone waveform signal having a complicated and special effect is obtained. In addition, since the random signal is used, the accumulated value of the accumulating means varies with noise characteristics as compared with the soft sync of the first embodiment. It will be expensive. Furthermore, various musical sound waveform signals can be obtained by appropriately changing the synchronization coefficient Hs between “0” and “1” or by varying it with time.

  In the second embodiment, instead of the random signal, another waveform signal that varies with time independently of the waveform signals in the master unit MA and the slave unit SL may be used.

  Next, a modification of the second embodiment will be described. FIG. 10 is a block diagram showing a musical tone waveform signal generator according to this modification. Instead of supplying the random signal of the second embodiment to the comparator 53, the adder 22 of the slave unit SL and The sawtooth wave signal Ps by the accumulating means comprising the storage element 23 is supplied to the comparator 53. As indicated by a broken line in FIG. 10, a waveform converter 54 is interposed in the signal path of the sawtooth wave signal Ps, and the sawtooth wave signal Ps is converted into a triangular wave and other waveforms to be compared with the comparator 53. You may make it supply to.

  According to this modification, the permission or prohibition of the synchronization control by the master unit MA is selectively performed in accordance with the control signal that is independent of the waveform signal in the master unit MA and that varies depending on the waveform signal in the slave unit SL. Will be conditioned. As a result, in this case as well, the initial value setting (reset) of the initial value of the accumulating means composed of the adder 22 and the storage element 23 may or may not be performed according to the sawtooth signal Ps. The function is performed halfway according to the control signal that varies depending on the waveform signal in the slave unit SL, and an effect similar to the soft sync function is obtained, and at the same time, it has a more complicated and special effect. A musical sound waveform signal is obtained. Also in this case, the synchronization coefficient Hs can be variously changed, as in the case of the second embodiment.

  Further, in the second embodiment and the modification thereof, the two switching circuits 26 and 51 provided in series are used. However, the switching circuit 51 is omitted, and each of the reset circuit 27 and the comparator 53 is used. The output signal may be guided to an electrical AND circuit, and the switching circuit 51 may be switched by the output of the AND circuit, so that the switching circuit 26 is switched using the logical product of the output signals. .

c. Third Embodiment Next, a third embodiment of the present invention will be described. A musical sound waveform signal generator according to the third embodiment is shown in a block diagram in FIG.

  The musical tone waveform signal generator according to the third embodiment includes a master unit MA and a slave unit as initial values at the time of resetting the accumulating means comprising the adder 22 and the storage element 23 of the slave unit SL of the first embodiment. This is because a control signal value that varies with time independently of SL is employed. Therefore, in the musical tone waveform signal generator of FIG. 11, the initial value arithmetic circuit comprising the divider 31 and the multiplier 32 and the initial value correcting circuit comprising the multipliers 34 and 35 and the adders 36 and 37 in the first embodiment. Is omitted, and a random signal generator (random number generator) 61 is connected to the second input terminal 26 b of the switching circuit 26.

  In the third embodiment, the sawtooth wave signal Pm formed by the accumulating means including the adder 12 and the storage element 13 of the master unit MA changes from “1” to “0”, and the reset circuit 27 When the reset signal is applied to the switching circuit 26, the random signal value from the random signal generator 61 is set as the initial value of the accumulating means comprising the adder 22 and the storage element 23 of the slave unit SL. As described above, when the accumulating means including the adder 22 and the storage element 23 of the slave unit SL is reset, a random signal value as a control signal that varies with time independently of the master unit MA and the slave unit SL is used as an initial value. Since it is given to the accumulating means, according to the third embodiment, a musical sound waveform signal having a complicated and special effect can be obtained. In particular, since a random signal is used as the control waveform signal for the initial value, the accumulated value of the accumulating means varies with noise characteristics compared to the soft sync of the first embodiment. Therefore, the musical sound waveform signal is extremely noisy. In particular, when a waveform generator such as a feedback FM is used as the waveform generator 24, the waveform itself can be continuously changed from a sine wave to a sawtooth wave, so that the tone color of noise can be changed more effectively.

  Next, a modification of the third embodiment will be described. As shown in FIG. 12, this modified example uses a random signal generator 61 of the third embodiment in place of the accumulated value of the accumulating means comprising the adder 22 and the storage element 23 in the first embodiment. Are supplied to an initial value correcting circuit comprising the multipliers 34 and 35 and the adders 36 and 37 of the first embodiment.

  According to this, in the initial value correcting circuit, the initial value by the initial value calculating circuit including the divider 31, the multiplier 32, and the adder 33 is corrected by the random signal from the random signal generator 61. As a result, randomness is added to the hard sync function, and the musical sound waveform signal generated in the slave portion SL becomes a noise sound having a pitch feeling. In addition, since the noise sound is assimilated to the master unit MA, only the noise sound is not unnaturally separated.

  In the third embodiment and its modification, instead of the random signal, another waveform signal that varies with time independently of the waveform signals in the master unit MA and the slave unit SL may be used. In this case, instead of the random signal generator 61, a control waveform signal generator that generates a waveform signal that varies at other times may be used.

d. Fourth Embodiment Next, a fourth embodiment of the present invention will be described. A musical sound waveform signal generating apparatus according to the fourth embodiment is shown in a block diagram in FIG.

  The musical tone waveform signal generator according to the fourth embodiment is provided with a conversion circuit 71 for converting the accumulated value in the accumulating means comprising the adder 22 and the storage element 23 of the slave unit SL of the first embodiment. It is characterized by that. The conversion circuit 71 includes multipliers 71 a and 71 b provided in series on a feedback path from the storage element 23 to the adder 22. The multiplier 71a multiplies the output value of the storage element 71a by the first feedback coefficient Rc (ratio) input to the first feedback coefficient information input terminal 72 and outputs the result. The multiplier 71b is configured as a modulo type that truncates bits exceeding “1”, and bit-shifts the input value by the second feedback coefficient Sc input to the second feedback coefficient information input terminal 73. The output value of the multiplier 71a is substantially multiplied by 1, 24, 8,... According to the second feedback coefficient Sc and output.

  In the fourth embodiment, the initial value of the accumulating means including the adder 22 and the storage element 23 is the initial value including the divider 31, the multiplier 32, and the adder 33 as in the first embodiment. Although an initial value by an arithmetic circuit can be used, the offset value Pi input to the offset information input terminal 41 is used as it is as the initial value. Therefore, the offset information input terminal 41 is directly connected to the second input terminal 26 b of the switching circuit 26.

  According to the fourth embodiment configured as described above, the accumulated value of the accumulating means comprising the adder 22 and the storage element 23 is converted by the conversion circuit 71 according to the first and second feedback coefficients Rc and Sc. Therefore, a musical sound waveform signal having a complicated and special effect can be obtained.

  Changes in the sawtooth wave signal Pm on the master unit MA side and the sawtooth wave signal Ps on the slave unit SL side when the accumulated value is variously changed by the conversion circuit 71 are shown in FIGS. In this case, the sampling frequency is 44.1 kHz, the master unit MA side fundamental frequency is 440 Hz, the slave unit SL side fundamental frequency is 660 Hz, the offset value Pi is “0”, and the second feedback coefficient Sc is “1” (bits). When the first feedback coefficient Rc is changed to “1.00”, “1.01” and “1.20” in the state set to “no shift”, the respective waveform diagrams of the sawtooth wave signals Pm and Ps correspond to FIGS. To do. Therefore, by changing the first and second feedback coefficients Rc and Sc from these waveform diagrams, the sawtooth wave signal Ps on the slave unit SL side changes in a complicated manner. As a result, the waveform generator 24 outputs the signal. It can be understood that the second musical sound waveform signal also changes in a complicated manner.

  In the fourth embodiment, as indicated by a broken line in FIG. 13, instead of using the offset value Pi as the initial value of the accumulating means including the adder 22 and the storage element 23, the random signal generator 74 Random signals can also be used. In addition, various waveform signals that vary with time can be used instead of the random signals. Further, instead of the conversion circuit 71, conversion means such as a conversion table having predetermined conversion characteristics or a conversion table whose conversion characteristics are variously changed by an input signal from the outside can be used.

  Further, in each of the above-described embodiments or their modifications, the initial value calculation circuit is configured by a divider 31, a multiplier 32, an adder 33, etc., but the initial value calculation circuit is as shown in the block diagram of FIG. It can also be configured. In this modified example, instead of the divider 31, the reciprocal conversion table 31a for converting the basic frequency information Fnm on the master unit MA side inputted to the first frequency information input terminal 11 into a reciprocal (1 / Fnm), and the same table A multiplier 31b that multiplies the output value of 31a by the sawtooth wave signal Pm that is the output of the adder 12 is used. The output of the multiplier 31b is connected to the multiplier 32. According to this, since the reciprocal conversion table 31a and the multiplier 31b provide a function equivalent to that of the divider 31 of the above embodiment, a complicated division operation by the divider 31 can be avoided. Further, in this initial value calculation circuit, a complicated division calculation by the divider 31 can be avoided by using a logarithm or the like as the frequency information Fnm, Fns.

  Further, in each of the above-described embodiments or modifications thereof, an accumulating unit comprising the adder 12 and the storage element 13 of the master unit MA, and an accumulating unit comprising the adder 22 and the storage element 23 of the slave unit SL, The sawtooth wave signals (phase information) Pm and Ps respectively output from 1 to 4 change in the range of “0” to “1”, but this range can be positive or negative such as “−1” to “+1”. It can also be changed as appropriate. In this case, the basic frequency information Fnm, Fns to be given is appropriately changed according to the range if the sawtooth wave signals Pm, Ps having the same period are to be obtained, and the waveform generators 14, 24, etc. The address value is also changed as appropriate.

  In each of the above embodiments or their modifications, the offset value Pi input to the offset information input terminal 41, the synchronization coefficient Hs input to the synchronization coefficient information input terminal 42, and the first and second feedback coefficient information Although a detailed description of the first and second feedback coefficients Rc and Sc input to the input terminal 72 is omitted, these values Pi and coefficients Hs, Rc, and Sc are operations provided in an electronic musical instrument or other electronic equipment. It is good to use what was given according to operation of a child, or memorized in memory as a parameter for deciding a tone color etc. Further, these values Pi and the coefficients Hs, Rc, Sc are changed according to the pitch of the generated sound waveform signal, or are changed temporally using an amplitude envelope waveform, an output waveform signal of a low frequency oscillator, and the like. You may do it.

  In each of the above embodiments or their modifications, the output waveform signals of the waveform generators 14 and 24 are output as musical tone waveform signals of the master unit MA and the slave unit SL, but the adders 12 and 22 and You may make it output the output of each accumulating means which consists of the memory elements 13 and 23 as a musical sound waveform signal through a filter etc. Furthermore, in the first to fourth embodiments, each circuit of the master unit MA and the slave unit SL is configured in hardware, but some of them may be performed by software processing by a computer. Moreover, you may make it comprise a musical sound wave form signal generator suitably combining each characteristic of the said 1st-4th embodiment and those modifications.

1 is a block diagram of a musical tone waveform signal generator according to a first embodiment of the present invention. FIG. 2 is an output signal waveform diagram of accumulating means in the master part and slave part of FIG. FIG. 6 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm, Ps and the second output waveform signal SO2 of FIG. 1 when the synchronization coefficient Hs is set to “1.0”. FIG. 6 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm and Ps and the second output waveform signal SO2 of FIG. 1 when the synchronization coefficient Hs is set to “0.0”. FIG. 6 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm, Ps and the second output waveform signal SO2 of FIG. 1 when the synchronization coefficient Hs is set to “0.75”. FIG. 6 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm, Ps and the second output waveform signal SO2 of FIG. 1 when the synchronization coefficient Hs is set to “0.50”. FIG. 6 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm and Ps and the second output waveform signal SO2 of FIG. 1 when the synchronization coefficient Hs is set to “0.25”. FIG. 6 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm and Ps and the second output waveform signal SO2 of FIG. 1 when the offset value is set to “0.2”. It is a block diagram of a musical tone waveform signal generator according to a second embodiment of the present invention. It is a block diagram of a musical sound waveform signal generator according to a modification of the second embodiment. It is a block diagram of a musical tone waveform signal generator according to a third embodiment of the present invention. It is a block diagram of a musical tone waveform signal generator according to a modification of the third embodiment. It is a block diagram of a musical tone waveform signal generator according to a fourth embodiment of the present invention. FIG. 15 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm and Ps of FIG. 14 when the first feedback coefficient Rc is set to “1.00”. FIG. 15 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm and Ps of FIG. 14 when the first feedback coefficient Rc is set to “1.01”. FIG. 15 is a waveform diagram showing temporal changes of the sawtooth wave signals Pm and Ps of FIG. 14 when the first feedback coefficient Rc is set to “1.20”. It is a block diagram which shows the modification of the initial value arithmetic circuit in each said embodiment.

Explanation of symbols

MA ... Master unit, SL ... Slave unit, 11, 21 ... Frequency information input terminal, 12, 22, 33, 36, 37 ... Adder, 13, 23 ... Storage element, 14, 24 ... Waveform generation unit, 15, 25 ... Output terminal, 26,51 ... Switching circuit, 27 ... Reset circuit, 31 ... Divisor, 32,34,35 ... Multiplier, 41 ... Offset information input terminal, 42 ... Synchronous coefficient information input terminal, 52,61,74 ... Random signal generator, 53 ... Comparator, 71 ... Conversion circuit, 72, 73 ... Feedback coefficient information input terminal.

Claims (1)

An arithmetic unit that calculates the input frequency information and the fed back accumulated value, and a storage element that stores the calculation result calculated by the arithmetic unit and that feeds back to the arithmetic unit as an accumulated value. Accumulating means for accumulating frequency information and outputting an accumulated value that changes in a cycle inversely proportional to the frequency information;
Control waveform signal generating means for generating a control waveform signal having a predetermined period;
Synchronizing means for setting the accumulated value of the accumulating means to a predetermined initial value in synchronization with the period of the control waveform signal;
A musical sound waveform signal generating apparatus provided with a conversion means provided in the accumulated value circulation path for converting the accumulated value with a predetermined conversion characteristic, and generating a musical sound waveform signal based on the accumulated value. .

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