JPS6329275B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a musical sound waveform forming apparatus in which amplitude values at sequential address points of a musical sound waveform are obtained by adding digital waveform values representing the fundamental tone to each overtone individually. In general, it is well known that musical instruments such as string instruments and wind instruments, as well as all other musical tones, are formed by a mixture of harmonic components that are integral multiples of the fundamental tone of the sine group. The timbre of a musical tone is determined by a musical waveform of a combination of pure sine waves and a volume envelope. From this point of view, it is important for electronic musical instruments to form the correct musical sound waveform suitable for the instrument, but in conventional electronic musical instruments, the circuit is constructed using an analog method, so it is easy for the performer to create a sound waveform. It was not possible to arbitrarily and effectively create any predetermined musical sound waveform by manipulation. The present invention has been made in view of the above points, and its purpose is to form a musical sound waveform by a combination of pure sine waves, and in particular, by inputting simple digital values. The present invention provides a musical sound waveform forming device that creates waveforms of any musical sound. In addition, other objectives are:
When forming a musical tone by combining multiple pure tones, it is possible to freely specify the harmonic order of the included pure tones and their relative amplitude ratios. The present invention provides a technology that makes it possible to easily obtain not only the tones of all kinds of musical instruments and living things, but also other new tones. First, prior to a specific circuit example of the system of the present invention, overtones and relative amplitudes based on the frequency spectrum of musical tones related to the present system will be explained. FIG. 1 shows the acoustic frequency spectrum of a violin, and the sound pressure level of overtones from the fundamental tone to, for example, the 20th overtone is generally expressed in decibels (dB). According to this, for the 30 dB of the 1st pure tone, which is the fundamental tone, the 2nd to 9th pure tones are 26 dB, the 10th pure tone is 22 dB, and the following to the 20th pure tone are 16 dB, 13 dB, 10 dB, 7.5 dB, 6dB, 4dB,
2dB, 1dB. In order to express each decibel value of the harmonic series of the frequency spectrum shown in FIG. 1 as a relative amplitude ratio for each pure tone in decimal values, amplitude ratio levels up to a maximum value of 31, for example, are set. When converting the numerical value B up to 31 into decibels (20 log B), 31→29.8dB, 30→
29.5dB, 29→29.2dB, 28→28.9dB, 27→28.6dB,
26→28.3dB, 25→28dB, 24→27.6dB, 23→
27.2dB, 22→26.8dB, 21→26.4dB, 20→26dB,
19 → 25.6dB, ......, 3 → 9.5dB, 2 → 6dB, 1.5
→3.5dB. Now, in order to specify the amplitude ratio expressed as a decimal value used in this system, for example, press the 17 amplitude specification keys "0", "1", "2", ......, "16". It is assumed that 16 amplitude ratio levels are provided, and the correspondence between decimal value amplitude ratios and decibels corresponding to these keys is expressed as shown in Table 1. It is assumed that the amplitude designation key "0" is operated when the sound does not contain integer overtones and has no amplitude.

[Table] Based on this Table 1, Table 2 shows each decibel of the harmonic series for the frequency spectrum of the violin shown in Figure 1 in correspondence with the amplitude ratio and amplitude specification key number used in this system. FIG. 2 is a relational diagram corresponding to FIG. 1.

【table】

[Table] Therefore, in this system, based on the frequency spectrum, for example, 10 pure tones from the 1st pure tone to the 20th pure tone are used.
The relative amplitude ratio in base numbers is specified by inputting numerical values in sequence. In this violin example, "16", "13", "13",
"13", "13", ......, "1", "1", "1", "
1"
and input them in order starting from the first pure tone. Then, in accordance with this numerical input order, the waveforms are cumulatively synthesized for each pure tone and written into the musical sound waveform storage device to form the final musical sound waveform. Hereinafter, embodiments of the present invention will be described in detail using the above-mentioned amplitude designation method with reference to the drawings. FIG. 3 is a diagram showing the musical sound waveform forming method of the present invention, and 1 is a pure tone amplitude designation input circuit for designating the amplitude of the sine wave pure tone mentioned above, and as shown in FIG. 4, "0", "1", ……, 17 keys 1a of “16”,
1b, 1c, ......, 1p are set. These keys 1a, ......, 1p are operated to select each pure tone from the fundamental tone to the 20th overtone, and the amplitude ratio of the pure tone is numerically encoded via the key input decoder 1q and supplied to the amplitude specification register 2 for each pure tone. At the same time, a key operation signal is output from the OR circuit /r and supplied to the tone writing control circuit 3. When a key is operated, this musical tone writing control circuit 3 outputs a set command signal to store a coded numerical value corresponding to the operated key in the amplitude designation register 2, and increments the pure tone number counter 4 by "+1". Output symbols. Next, a signal is output from the output terminal of the musical tone writing control circuit 3, and this signal becomes a "+1" increment signal to the overtone control counter 5, a step signal to the sine wave step counter 6, and a step signal to the AND circuit 7. Provided as input gate signal. The signal from this output terminal is also given as a write command to the buffer memory 8 and a read command to the tone waveform storage device 9, which will be described in detail later, so that information in the tone waveform storage device 9 is written to the buffer memory 8. Sine wave step counter 6
In this case, it is composed of a 9-bit binary counter that obtains 512 counting states from 0 to 511, and each bit stage is sequentially weighted with 1, 2, 4, . . . , 256. The output signals from each bit stage of the lower 4-bit lower counter 6a and the signals obtained from the output signals via the inverters 10, . ..., 22. Further, output signals from the 1st, 2nd, 4th, and 8th bit stages of the amplitude designation register 2 are supplied to input lines 27, 28, 29, and 30 of the AND circuit group 14, respectively. FIG. 16 shows an explanation of the logic symbols used in the AND circuit group 14.
FIG. 16 shows that input lines A, B, and C are selectively logically combined to obtain output lines l, m, and n. It constitutes the AND circuit group 14. Output line 3 of this AND circuit group 31
2, . Logic symbols used in this OR circuit 37 are shown in FIG. FIG. 17 shows that input lines A, B, C, and D are logically added to obtain output line l. The output of the OR circuit 37 is output from the AND circuit 7.
is coupled to the input gate of Further, an OR circuit 38 is coupled to the third input terminal of the AND circuit 7. That is, the outputs from the 1st, 2nd, 4th, and 8th bit stages of the lower counter 6a of the sine wave step counter 6 are sent to the output terminals of the tone writing control circuit 3, as shown in FIG. 5a, b, c, and d. A binary counting operation is performed every time an input pulse φ is counted. In FIG. 5, the portion indicated by a line indicates the presence of a pulse signal, that is, the "1" level. Therefore, the output from the AND circuit 7 is
By selecting the AND circuit group 31 according to the stored value of the encoded numerical value set in the amplitude designation register 2, the values i, j, . . . in FIG. ..., an output signal like x is obtained. For example, when the stored value is "00001" (number 16), the AND circuit 7 sends 16 pulse signals φ during one cycle of the lower counter 6a as shown in FIG. ), as shown in Fig. 5j, during one cycle of the lower counter 6a.
Fifteen pulse signals φ are obtained, and the number of pulse signals φ corresponding to each numerical value is outputted from the AND circuit 7. Upper counter 6b of sine wave step counter 6
The outputs from each bit stage with weights of 16, 32, 64, and 128 are input to a sine wave region and direction designation decoder 39, which will be described later, to generate an X (0.5) signal and a Y (1) signal.
The signal is coupled to the OR circuit 38, and the output signal from the 256 weight bit stage of the upper counter 6b is coupled together with the Z signal from the decoder 39 to the input of an exclusive OR circuit 40. The output signal from this exclusive OR circuit 40 is sent to the amplitude counter 41.
is supplied as a down command signal. This amplitude counter 41 is composed of an 8-bit binary counter that performs up-down counting operation, and has an initial value of "0".
The counting operation is performed as shown in Table 3 with reference to .

[Table] On the other hand, the X and Y signals from the sine wave region and direction decoder 39 are also coupled to one input terminal of each of the AND circuits 42 and 43, respectively.
The output signal from the AND circuit 7 is supplied to the other input terminal of 43. The output of the AND circuit 42 is coupled via a 1-bit binary counter 44, and the output of the AND circuit 43 is directly coupled to the respective input terminals of an OR circuit 45. The output of this OR circuit 45 is supplied as a count signal to the amplitude counter 41. The sine wave region and direction designation decoder 39 is set based on the sine wave equalized waveform shown in FIG. As you can see from Figure 6, dot points (black circles)
The actual sine wave curve drawn along the point a, b
It can be said that the waveform (sine wave equalized waveform) in which points C, C, D, E, and F are connected by straight lines is extremely approximate. Therefore, this system is based on this sine wave equalized waveform in consideration of digital processing. Now, in the half cycle (solid line part) of this sine wave equalized waveform, the upper counter 6b of the sine wave step counter 6 is set according to the angular direction.
When divided into 16 steps of 0, ......, 15 in the order of the count value, the count value is 0, ......, 4 (from point a to point b)
Until then, it rises at a ratio of 1:1 ("+1"), at count values 5 and 6 (from point b to point c) it rises at a ratio of 1:0.5, and at count values 7 and 8 (from point c to point d) it rises at a ratio of 1:0.5. And, for count values 9 and 10 (from point d to point e), the ratio is 1:0.5 ("-1"), and for count values 11 to 15 (from point e to point f), the ratio is 1:1. It is expressed as falling. Of course, in the case of a full wave, it is sufficient to add the part shown by the dotted line in Figure 6. 7th
The figure is a circuit diagram of the sine wave region and direction specifying decoder 39 specifically showing the relationship shown in FIG. 39a, and the outputs of the 64 and 128 weight bit stages are coupled to respective inputs of a second exclusive OR circuit 39b. These first and second exclusive OR circuits 39a,
The output of 39b is coupled to each input terminal of AND circuit 39c, and the output of this AND circuit 39c is coupled to one input terminal of AND circuit 39d, and also to one input terminal of inverter 39e.
It is coupled to one input terminal of the AND circuit 39f via. Furthermore, the outputs of the bit stages with weights of 16, 32, and 64 of the upper counter 6b are output via inverters 39g, 39h, and 39i, respectively, and the outputs of the bit stages with weights of 128 are sent to an AND circuit 39j.
is combined with On the other hand, 16 of upper counter 6b,
The output of each bit stage having a weight of 32 and 64 and the output obtained by inverting the output of a bit stage having a weight of 128 by an inverter 39k are coupled to an AND circuit 39l.
The AND circuits 39j and 39l are coupled to the other input terminals of the AND circuits 39d and 39f via an OR circuit 39m and an inverter 39n.
That is, an X signal (0.5 area command signal) and a Y signal (1 area command signal) are obtained from each output of the AND circuits 39d and 39f. Further, the 128-weight bit stage output signal of the upper counter 6b becomes a Z signal (a "-" down command signal). The amplitude counter 41 is composed of an 8-bit binary counter that operates up and down, and counts up and down the clock signal output from the OR circuit 45 based on the up and down commands from the exclusive OR circuit 40. It is something. Furthermore, the output signal from the 8th bit of the amplitude counter 41 is divided into 5 outputs, and is sent to the adder circuit 4 as 12-bit parallel information along with the outputs up to the lower 7 bits.
6. When the coincidence signal from the coincidence circuit 51 is input to the musical tone writing control circuit 3,
An addition command signal is output from the output end of the musical tone writing control circuit 3 to the addition circuit 46,
This adder circuit 46 adds the 12-bit parallel information output of the buffer memory 8 and the output of the amplitude counter 41, and supplies the addition result as 12-bit parallel information to the musical waveform storage device 9 in response to the write command. be. This musical waveform storage device 9 is, for example, a RAM (random access memory).
It has the number of address steps corresponding to the number of steps of the sine wave step counter 6, and in this system it is 256 (steps) x 12 (bits).
It has a storage capacity of 3072 bits and can store half waves of musical waveforms. The tone waveform storage device 9 also includes an address counter 47 having 256 address steps counted in binary with 3 bits.
Addresses are sequentially specified according to the counting order of , and the counting step is performed by a signal output from the output terminal of the musical tone writing control circuit 3. The signal from the output terminal of this musical tone writing control circuit 3 is
It is output after the signal from the output terminal of the musical tone writing control circuit 3 is output. The signal from the output terminal of the tone writing control circuit 3 is also applied to the overtone control counter 5 as a reset signal. When the address counter 47 is incremented by the signal from the output terminal and outputs a carry signal, this carry signal is supplied to the sine wave step counter 6 as a reset signal, the amplitude counter 41 as a clear signal, and the AND circuit 50 as a gate signal. . Also, address counter 4
Since the value of 7 becomes "0", a "1" signal is outputted via the OR circuit 48 and the inverter 49, inputted to the musical tone writing control circuit, and inhibits the output of the signal from the output terminal. A bit stage output signal having weights of 4 and 16 from the pure tone number counter 4 is applied to the other input terminal of the AND circuit 50, and the pure tone number counter 4 is reset in synchronization with the carry signal when the count value is "20". That's how it happens. Each bit level output of the pure tone number counter 4 and each bit level output of the overtone control counter 5 are applied to a matching circuit 51, and the matching output signal is supplied to the tone writing control circuit 3. This matching circuit 51 is shown in FIG.
The output inverted by 1e is connected to AND circuits 51f and 51f, respectively.
......, 51j, and the outputs of these AND circuits 51f, . . . , 51j are taken out as a coincidence detection signal via an OR circuit 51k and an inverter 51l. Reference numeral 52 detects the "10000" state of the pure tone number counter 4, and uses this detection output to reset the buffer memory 8. As shown in FIG. 8, the inverter 52a,
...... 52d and an AND circuit 52e. The details of the tone writing control circuit 3 are shown in FIG. 9. The key operation signal operated by the pure tone amplitude designation input circuit 1 is applied to a delayed flip-flop (referred to as DFF) 3a, and is applied to a clock pulse CP. Output synchronously. this
The output from DFF3a is also applied to one input terminal of DFF3b and AND circuit 3c, and the side output of DFF3b is applied to the other input terminal of AND circuit 3c. A one-shot key signal as shown in Figure a is obtained. That is, this key signal is output from the output terminal to the amplitude designation register 2 as a set command signal and to the pure tone number counter 4 as a "+1" increment signal. Further, the output signal from the AND circuit 3c is applied to the DFF 3e via the OR circuit 3d. Then, DFF is synchronized with clock pulse CP.
The signal output from 3e is applied to DFF 3f and also supplied to AND circuit 3g. Therefore, this AND circuit 3g outputs the clock pulse CP
The signal shown in FIG. 10b is output from the output terminal in synchronization with the output terminal, and a read command is sent to the musical waveform storage device 9, a "+1" step step command is sent to the sine wave step counter 6, and a "+1" step step is sent to the overtone control counter 5. Obtain advance command. Next, the DFF 3f supplies a signal to one input terminal of the AND circuits 3h and 3i in synchronization with the clock pulse CP. The other input terminal of the AND circuit 3h receives the coincidence detection signal from the coincidence circuit 51, and the other input terminal of the AND circuit 3i receives the coincidence detection signal from the inverter 3.
An inverted signal is applied at j. The output of the AND circuit 3h generates the output signal shown in FIG.
It is also applied to k. Further, the output signal of the AND circuit 3i is applied to the input of the OR circuit 3d.
DFF3k is output in synchronization with clock pulse CP and supplied to one input terminal of AND circuits 3l and 3m. This AND circuit 3l generates the output signal shown in FIG. The "0" detection signal of the address counter 47 is connected to the other input terminal of the AND circuit 3m.
is applied via the OR circuit 3d, and its output is applied via the OR circuit 3d.
is applied to That is, the musical tone writing control circuit 3 in FIG.
It controls the entire system shown in the figure, and increments the steps of the address counter 47 of the musical waveform storage device 9 and the sine wave step counter in response to the overtone order m of the pure tone counted by the pure tone number counter 4. and is controlled at a ratio of 1:m. For example, if the pure tone number counter 4 specifies the 4th harmonic and the count value is 4 ("00100"), the AND circuit 3
i. An output signal is obtained from the output end four times via the OR circuit 3d, and during this period, no signal is output from the output end, and only the overtone control counter 5 and the sine wave step counter 6 are incremented. and,
Due to the signal from the output terminal, the count value of the overtone control counter 5 becomes (00100) and when it matches the count value of the pure tone number counter 4, the gate of the AND circuit 3i is closed and the AND circuit 3h is opened, resulting in a musical sound waveform. The addition result from the addition circuit is written into the storage device 9. Thereafter, since a signal is obtained from the output terminal, the address counter 47 is incremented by 1 at this point. At the same time, the overtone control counter 5 is reset by the signal from the output terminal, and since the output signal from the AND circuit 3m is now supplied to the OR circuit 3d, the overtone control counter 5 starts counting from "1" again. In this way, in the case of the fourth harmonic, the address counter 47 is incremented once every four times the output signal is obtained from the output terminal. and,
Such an operation is repeated until the address counter 47 reaches the initial value "0", and when the address counter reaches "0", the output of the AND circuit 3m is prohibited, so that the fourth harmonic musical waveform storage device 9
The write operation ends. Such an operation is performed for each harmonic order; for the 5th harmonic, the address counter 47 is incremented once every 5 steps of the sine wave step counter 6, and for the 6th harmonic, the address counter 47 is incremented once for every 5 steps. The address counter 47 is incremented once, once every 7 steps for the 7th harmonic, once every 20 steps for the 20th harmonic. Once a desired tone waveform is stored in the tone waveform storage device 9, this tone waveform is read out and controlled during performance, but since this readout is not the gist of the present invention, detailed drawings will not be added. However, I will explain it briefly. When performing, for example, a keyboard consisting of a large number of keys is prepared, and pitches for scales and octaves are specified by operating this keyboard. Then, the address counter 47 for the tone waveform storage device 9 is incremented in steps at a clock speed corresponding to the designated pitch to read out the tone waveform. In this case, in this system, since only a half-wave musical sound waveform is stored in the musical sound waveform storage device 9, the address counter 47 is operated to perform an up-down counting operation during read-out performance, and after 256 steps, the address counter 47 is operated to perform a down-counting operation. The stored tone waveform is read out in reverse and its polarity is inverted. Then, the read musical sound waveform is D-
A-conversion (not shown) is performed, and the volume is controlled by an envelope to obtain a musical tone corresponding to the pitch from a speaker (not shown). Next, the operation based on the above embodiment will be explained. Now, by the pure tone amplitude specification input circuit 1, the amplitude specification key is set to "16" from the 1st pure tone to the 4th pure tone.
To explain the case where the keys are operated in the order of "16", "0", and "8", first, when the first key "16" is operated, this number is converted into a numerical code by the key input decoder 1q and becomes "00001" (number 16). ) signal is outputted, and at the same time, a key operation signal is outputted from the OR circuit 1j and applied to the DFF 3a of the musical tone writing control circuit 3. As a result, the output of the AND circuit 3c, that is, the output signal shown in FIG.
16) At the same time as the signal is preset, the pure tone number counter 4 is incremented by +1 and enters a counting state of "10000" (numerical value 1). At that time, 52 is the pure tone number counter 4
The count state of "10000" is detected and the buffer memory 8 is reset. Next, in the musical tone writing control circuit 3, the output from the AND circuit 3c
DFF3e is set, and the pulse signal shown in FIG. 10b is generated from the output terminal in synchronization with the clock pulse CP. At this point, 16 of amplitude specification register 2
A "1" signal is output from the bit stage output of the wait, and the sine wave region and direction designation decoder 39 outputs "00000" from the upper counter 6b. Depending on the state, a Y1 signal is applied to the AND circuit 7 via the OR circuit 38. Therefore, the AND circuit 7 outputs a pulse signal. This pulse signal further passes through an AND circuit 43 and an OR circuit 45 to cause the amplitude counter 41 to count by +1 from the initial value "0" as shown in Table 3 above. Further, a read command is given to the musical sound waveform storage device 9 by a signal from the output terminal of the musical tone writing control circuit, and 12
Bit parallel information (in this case "000000000000")
is written into the buffer memory 8. Next, the DFF 3f of the musical tone writing control circuit 3 is set, and at this time, the overtone control counter 5 is incremented by the signal from the output terminal and is in a counting state of "10000", so a coincidence signal is output from the coincidence circuit 51. Therefore, the signal shown in FIG. 10c is output from the AND circuit 3h. This output signal is output from the output terminal and supplies an addition command to the addition circuit 46 and a write command to the musical waveform storage device 9, so the buffer memory 8
The information “00…00” at the “0” address of the musical waveform storage device 9 written in is added to the +1 count information “10…0” of the amplitude counter 41, and the addition result is “100…00”. . . . 0” information is written to the “0” address of the tone waveform storage device 9. Next, the DFF 3k is set by the output signal of the AND circuit 3h of the tone writing control circuit 3, and the output signal shown in FIG. 10d is generated from the output of the AND circuit 3l in synchronization with the clock pulse CP. It is incremented by +1 and the tone waveform storage device 9 enters the next addressing state. moreover,
The overtone control counter 5 is reset by the signal from the output end. At this point, an output signal is also obtained from the AND circuit 3m of the musical tone writing control circuit 3, and is again passed through the OR circuit 3d to the DFF3e.
is set, and the output signal shown in FIG. 10b is generated from the output terminal via the AND circuit 3g. Therefore,
The same operation as above is performed again with the ugly signal from the output end, but the amplitude counter 41 is in the +2 counting state "010...0", and this count value is used as the amplitude value of the musical sound waveform. It is written to the “1” address of the storage device 9. Furthermore, by repeating this operation, the address step is sequentially performed in the tone waveform storage device 9, and the step count value of the amplitude counter 41 is "3" (110...0), "4" (0010...)
0), ...... are written to the corresponding address.
FIG. 11 shows the count step state of the amplitude counter 41 in waveform form, where the A curve is a first-order pure tone. Then, when the upper counter 6b of the sine wave step counter 6 reaches "5" counting state "10100", the X signal is output from the sine wave region and direction designation decoder 39, so the AND circuit 43 is heard and the AND circuit 42 is opened. Therefore, the pulse signal output from the AND circuit 7 is sent to the binary counter 44.
is supplied to Therefore, in this case, the amplitude counter 41 operates so as to be incremented once every time two pulse signals are output from the AND circuit 7. In other words, when the upper counter 6b is counting "5" and "6", the amplitude counter 41 is incremented once every +2 steps of the sine wave step counter 6, as seen from the curve A in FIG. Become. When the upper counter 6b is counting "7" or "8", the amplitude counter 41 is not supplied with any up/down signals and is in a counting halt state (count value "96"). Further, when the above-mentioned operation by the musical tone writing control circuit 3 is repeated, a Z(-) signal is output from the sine wave region and direction designation decoder 39 when the high-order counter 6b is in the counting state of "9" to "15". Therefore, a down command is given to the amplitude counter 41, and the maximum count value "96" of the amplitude counter 41 is subtracted. Therefore, for the first pure tone of the first key "16", a half-wave waveform is written and stored in the corresponding address of the tone waveform storage device 9 in the count value state according to the curve A in FIG. Then, the address counter 47
When the operation is completed up to 256 steps, a carrier signal is output from the address counter 47 and the amplitude counter 4
1. The sine wave step counter 6 is reset,
The amplitude value writing operation of the first pure tone ends in the "0" address counting state. Next, when the "16" key is operated for the second pure tone, the pure tone number counter 4 is incremented by the signal from the output terminal of the musical tone writing control circuit 3, and becomes a counting state of "01000", and the amplitude designation register 2 "00001" is stored again. Then, the sine wave step counter 6 and overtone control counter 5 are incremented by +1 by the signal from the output terminal of the musical tone writing control circuit 3, but since there is no coincidence detection signal from the coincidence circuit 51 at this point, musical tone writing control is performed. The AND circuit 3h of the circuit 3 is not opened and no signal is obtained from the output terminal. On the other hand, since a signal is output from the AND circuit 3i, the OR circuit 3d
The DFF 3e is set again through the AND circuit 3g, a signal is generated from the output end, a read command is given to the musical waveform storage device 9, and the stored value "100...0" is read out from the "0" address and stored in the buffer memory 8. Write. At the same time, the overtone control counter 5 and the sine wave step counter 6 are incremented, and the amplitude counter 41 becomes +2 counting state "010...0". A coincidence signal is obtained from the coincidence circuit 51 by this second signal from the output terminal, and a signal is generated from the output terminal and an addition command is sent to the addition circuit 46.
Since a write command is given to the musical sound waveform storage device 9, "100...0" in the buffer memory 8 and "010...0" in the amplitude counter 41 are added, and the addition result is "110...0". It is written to the "0" address of the tone waveform storage device. Therefore, this kind of operation is repeated one after another, and the second pure tone is the same as the first one.
The amplitude counter 41 performs a counting operation as shown in FIG.
The accumulated value will be stored. here,
Since the counting operation of the amplitude counter 41 is as described in Table 3, for example, at point X (address 30) in FIG. 0” (secondary pure tone) =
92 count value "101110100...0", and 59 count value "1101110...0" at Y point (address 197)
(1st pure tone) + (-96) count value “011111001111”
(2nd pure tone) = (-37) Count value “100110111111”
will be stored at the corresponding address in the musical sound wave storage device 9. In this way, the tone waveform storage device 9 stores the accumulated values of A and B in FIG. 11 for each address. Furthermore, for the 3rd harmonic, since the "0" key is operated, the pure tone number counter 4 is incremented by +1 and becomes a counting state of "11000", but since "00000" is written in the amplitude designation register 2, the amplitude counter 41
does not perform a counting operation and is in the "0" state, so there is no change in the stored value in the tone waveform storage device 9. Next, for the 4th harmonic, the "8" key is operated,
The pure tone number counter 4 becomes "00100", and the amplitude designation register 2 stores "00010". In this case as well, the same operation as described above is repeated, and in the end, the amplitude counter 41 performs the counting operation as shown in FIG. 11C. The tone waveform storage device 9 stores the accumulated counts of A, B, and C in FIG. 11 for each address. In this way, this system can accumulate the amplitude values for each pure tone up to the 20th overtone, thereby creating the final desired musical sound waveform. In the above explanation, as shown in Fig. 11, musical waveforms were formed by directly accumulating the amplitude values for each step of each pure tone. It is also possible to accumulate. That is, in this case, in the circuit diagram of FIG. 3, the amplitude counter 41 is reset by the output signal from the output terminal of the tone writing control circuit 3. This amplitude change value is
This will be explained using FIG. 12, which is a partially enlarged view of FIGS. 1A and 1B. As can be seen from Fig. 12, the amplitude counter 4
1, when the amplitude changes from the immediately previous step, only the changed value is counted, and the musical waveform storage device 9 accumulates and stores the amplitude change value for each address of each pure tone. . That is, the first
In the first pure tone A in FIG.
"+3", "+3" are obtained by storing only the change value of "1" and further accumulating the change value of B of the second pure tone "+2", "+2", ..... "+2" for each address. …
"+3" is now stored. Note that when there is no amplitude change, the change value is "0". When a musical sound waveform as an amplitude change value is read out during performance to obtain a musical tone, the amplitude change values read out in address order may be cumulatively added using an adder circuit and an accumulator (not shown). It is something. As described in detail above, according to the musical sound waveform forming device of the present invention, it is possible to arbitrarily specify the individual composition ratios of the fundamental tone or each higher-order overtone by digital numerical setting, so that various musical sound waveforms can be easily created. It is possible to easily create new tones not only for musical instruments but also for other instruments, and the performance effect is extremely great. Furthermore, the present invention allows the performer to sequentially input digital information indicating the composition ratio of each of the fundamental tone to each higher harmonic by using a set of switch means in common, so that the input device can It is compact, and digital information indicating the composition ratio of many high-order overtones can be easily input. In the embodiment described above, the tone waveform storage device 9 is configured to store half-wave tone waveforms, but it is of course possible to store full-wave tone waveforms. In this case, the storage capacity of the tone waveform storage device 9 may be doubled. Furthermore, although this embodiment was designed based on the sine wave equalization waveform shown in FIG. 6, it may also be designed based on a trapezoidal sine wave equalization waveform as shown in FIG. 13, for example. In that case, the sine wave region and direction designation decoder 39 are changed, and the X signal and 1-bit binary counter 44 are no longer necessary. In the above embodiment, the pure tone amplitude designation input circuit 1 has been described using a key designation method using a plurality of independent keys, but it may also be a dial setting method, a combination designation method with a keyboard key, or a numerical designation method using a numeric keypad. , a circuit for extracting the X, Y, and Z signals using the sine wave region and direction designation decoder 39 may be of a counting type as shown in FIG. 14, for example. That is, to briefly explain the circuit of FIG. 14, based on the output of each bit stage from the upper counter 6b of the sine wave step counter 6, the AND circuit group 39p inputs "0", "5", "7", and "9". ”, “11” are detected, and each time the count value of 4 is detected through the OR circuit 39q,
The bit binary counter 39r may be incremented, and the X(0.5) and Y(1) detection signals may be extracted from the count value state of the counter 39r via an AND circuit group 39s and an OR circuit 39t. In addition, in FIG. 3, the overtone control counter 5 is reset each time the coincidence circuit 51 detects a coincidence between the counts of the overtone control counter 5 and the pure tone number counter 4. For example, as shown in FIG. 15, the count value of the overtone number counter 4 is preset in the overtone control counter 5 via the transfer gate by a transfer command, and the output from the output terminal of the musical tone writing control circuit 3 is calculated from this preset value. It may be configured to count down by -1 until "0" is detected in the signal. Furthermore, in the above embodiment, the key input operation was performed sequentially from the 1st pure tone to the 20th pure tone, but this is changed to a configuration in which the high-order pure tones are specified sequentially from the 20th pure tone to the 1st pure tone. You can also. In this case, the pure tone number counter 4 may be sequentially decremented from the count value "20". In addition, in the above example, as shown in Table 1, 17
Although more keys are used, more keys may be used to specify numerical values with higher precision. In addition, it goes without saying that the circuit shown in FIG. 3 can be modified in various ways without departing from the gist of the present invention.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the acoustic frequency spectrum,
FIG. 2 is a diagram explaining the relative amplitude ratio expressed in decimal values used in the present invention, FIG. 3 is an overall circuit diagram of the present invention, FIG. 4 is a detailed diagram of the third amplitude designation input circuit, and FIG. Fig. 5 is a waveform diagram for explaining the operation of Fig. 3, Fig. 6 is a sine wave equalization waveform diagram used in the present invention of Fig. 3, and Fig. 7 is a sine wave region and direction designation decoder of Fig. 3. , FIG. 8 is a detailed diagram of the matching circuit, FIG. 9 is a detailed diagram of the musical tone writing control circuit, FIG. 10 is an explanation of the operation of FIG. 9, and FIG. 11 is an explanation of the operation of FIG. 3. 12 is a diagram explaining the amplitude change value method of the present invention, FIG. 13 is another sine wave equalization waveform diagram based on FIG. 6, and FIG. 14 is a sine wave region and Another embodiment of the direction specifying circuit, FIG. 15 shows another embodiment in which the matching circuit in FIG. 3 is not used, and FIGS. 16 and 17 explain the logic symbols used in this embodiment. These are explanatory diagrams corresponding to an AND circuit group 14 and an OR circuit 37, respectively. 1... Amplitude specification input circuit, 2... Amplitude specification register, 3... Musical tone writing control circuit, 4... Pure tone number counter, 5... Overtone control counter, 6...
... Sine wave step counter, 8 ... Buffer memory, 9 ... Musical waveform storage device, 39 ... Sine wave area and direction designation decoder, 41 ... Amplitude counter, 46 ... Addition circuit, 47 ... Address counter, 51 ... ...matching circuit.

Claims (1)

[Scope of Claims] 1. Amplitude values at sequential address points of a musical sound waveform are obtained by adding digital waveform values representing the fundamental tone or each higher-order overtone individually, and an input means for allowing a performer to input a signal indicating the composition ratio of each overtone; a storage means for storing the signal inputted by the input means; and a storage means for storing the signal inputted by the input means; and means for controlling the composition ratio of the fundamental tone to each higher-order harmonic to obtain an amplitude value at each address point, A musical sound waveform forming apparatus comprising an input means for sequentially inputting the signals indicating individual composition ratios at different timings. 2. Amplitude values at sequential address points of a musical sound waveform are obtained by adding digital waveform values that individually represent the fundamental tone or each higher-order overtone, and the amplitude values are obtained by adding digital waveform values that individually represent the fundamental tone or each higher-order overtone, and the individual configurations of the fundamental tone or each higher-order overtone are an input means for allowing a performer to input a signal indicating the ratio; a storage means for storing the signal inputted by the input means; and a storage means for storing the signal inputted by the input means; means for controlling the composition ratio of the next harmonic to obtain an amplitude value at each address point; a memory means for storing the calculated amplitude value at each address point; and each address stored in the memory means. A musical waveform forming device comprising means for reading out the amplitude value of a point at a speed according to the pitch of an output musical tone, wherein the input means is configured to receive the signal indicating the individual composition ratio for each of the fundamental tone to each higher-order overtone. What is claimed is: 1. A musical sound waveform forming device comprising an input means for sequentially inputting at different timings.