JPS6115438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a musical tone signal generating device using a so-called waveform memory read method, which generates musical tone signals by reading musical waveforms stored in a waveform memory in advance.

In an electronic musical instrument using a musical tone signal generation device using a conventional waveform memory reading method, a waveform memory storing a desired waveform is read out using a readout address signal corresponding to a pressed key, and this readout waveform signal is used as a musical tone signal. This was then multiplied by an envelope waveform for volume control to generate musical tones.

Therefore, since the musical tone signal generated in the conventional waveform memory read type musical tone signal generator is a repetition of the same waveform, the tone color thereof is always the same and does not change.

By the way, the tone color (waveform shape) of the musical tones of natural musical instruments generally changes over time, resulting in a richer sound. Therefore,
Conventional musical tone signal generators using a waveform memory reading method generate musical tones that lack richness and produce monotonous sounds.

In view of the above-mentioned drawbacks of the conventional waveform memory read type musical tone signal generation device, the applicant of this patent has disclosed the invention disclosed in Japanese Patent Application No. 52-48412 and Japanese Patent Application No. 52-51970. He made a new invention.

First Prior Invention: According to Japanese Patent Application No. 52-48412, a plurality of waveform memories are provided which store different waveforms and are read out simultaneously, and furthermore, a time period corresponding to each waveform memory is provided. A parameter generator is provided for generating a varying parameter signal. In addition, the waveform signals output from each waveform memory (Wi i=1, 2......) and the parameter signals output from the parameter generator (Pi
(t), i=1, 2...) are provided on the output side of each waveform memory, and the output side of each multiplier is connected to the input side of the adder. Therefore, the waveform signal (Wi, i=1, 2......) output from each waveform memory is converted to Σ by each parameter signal (Pi(t)i=1, 2......)
The signals are synthesized in the form of Wi·Pi(t) to form a musical tone signal whose timbre changes from musical tone generation to end.

Further, according to the second prior invention: Japanese Patent Application No. 52-51970, the first invention, which stores different waveforms from each other,
A second waveform memory is provided, the first,
Each waveform signal output from the second waveform memory is synthesized using a time-varying parameter signal P(t) at a ratio of [P(t):1-P(t)],
A musical tone signal whose timbre changes is formed from the generation of the musical tone to the end of the musical tone.

As is clear from the above explanation, the first
According to the second prior invention, a musical tone signal is formed by multiplying a waveform signal output from a waveform memory by a parameter signal output from a parameter signal generator. Therefore, it was possible to obtain a musical tone signal whose waveform shape gradually changes from the generation to the end of the musical tone. However, the parameter signal generators in these prior inventions are usually constructed of a read-only memory or the like with a small memory size in order to prevent the scale of the musical tone signal generator from increasing. Therefore,
The parameter signal output from the parameter signal generator changes very slowly over time, and the rate of change in the waveform shape of the generated musical tone signal per unit time is also very small. For example, since the parameter signal hardly changes within one period of the waveform signal read out from the waveform memory, the parameter signal of the same value is multiplied. Therefore,
The musical tone signal generated in this prior invention had a drawback in that the range of timbre change was narrow.

The present invention has been made in view of the drawbacks of the conventional musical tone signal generating device and the prior invention as described above, and an object of the present invention is to provide a musical tone signal generating device capable of generating a musical tone signal whose waveform shape changes significantly. With the goal.

In order to achieve this object, the musical tone signal generating device of the present invention is characterized in that a control means is added to the basic configuration consisting of an address signal generation means, a waveform storage means, a parameter signal generation means, and a synthesis means. That is. The address signal generation means generates an address signal that changes sequentially in response to a desired pitch, and the waveform signals related to a plurality of mutually different waveforms stored in the waveform storage means are respectively read out by the above-mentioned address signals. The synthesizer weights each read waveform signal and outputs it as a musical tone signal, and a weight parameter signal for this weighting is given from the parameter signal generator to the synthesizer. The control means detects that the address signal has reached a predetermined value and switches and changes the weight parameter signal given from the parameter signal generation means to the synthesis means.

The present invention will be described in more detail below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of an electronic musical instrument using the musical tone signal generating device of the present invention.
It is configured to output a logical value "1" to the output line of the book. The keyboard circuit 1 has a built-in single note priority circuit (not shown), and the single note priority circuit has a function of determining only one note to be produced when two or more keys are pressed at the same time. As this single tone priority circuit, for example, Japanese Patent Application No. 49-102640
29918) can be used. Furthermore, the keyboard circuit 1 has a function of outputting a key-on signal KON indicating that a certain key has been pressed. Each output line of the keyboard circuit 1 is connected to the input side of a frequency information memory 2, and the frequency information memory 2 stores frequency information values (constants) F corresponding to the pitches of each key. Therefore, when a certain key is pressed, the frequency information value F corresponding to the pitch of that key is read out from the frequency information memory 2. The output side of the frequency information memory 2 is connected to the input side of an accumulator 3, and the accumulator 3 receives the clock pulse _φ1 and sequentially accumulates the frequency information value F read out from the frequency information memory 2. The cumulative value qF is sequentially output as a read address signal.

Here, when the accumulator 3 accumulates up to the maximum possible accumulation value, it starts again from the beginning with the frequency information value F.
It is configured to perform the accumulation of . Therefore, the read address signal (accumulated value qF) is repeatedly output. Note that the frequency information memory 2 and the accumulator 3 constitute address signal generating means. The output side of the accumulator 3 is connected to the input sides of waveform memories 4 and 5 constituting the waveform storage means and to the input terminal A of the comparator 9. Here, it is assumed that waveform memories 4 and 5 store waveforms W1 and W2 shown in FIGS. 2A and 2B, respectively.

As is clear from the above explanation, the frequency information value F corresponding to the pressed key is stored in the frequency information memory 2.
This is sequentially accumulated by the accumulator 3 at the timing of the clock pulse _φ1 , and the accumulated value qF is inputted to the waveform memories 4 and 5 as a read address signal. Therefore, the waveform memory 4,
5 output waveform signals W1 and W2 of frequencies corresponding to the pitches of the pressed keys, respectively.

The output side of the waveform memory 4 is connected to a first input terminal of a multiplier 6, and the output side of the waveform memory 5 is connected to a first input terminal of a multiplier 7. Further, the constant C is input to the input terminal B of the comparator 9, and the comparator 9 compares the magnitude of the accumulated value qF input to the input terminal A and the constant C input to the input terminal B. If (accumulated value qF) < (constant C), a logical value “0” is output from output terminal 0, and (accumulated value
When qF)≧(constant C), a logical value “1” is output from output terminal 0. An output terminal 0 of this comparator 9 is connected to a select command input terminal S of selectors 10 and 11. The key-on signal KON output from the keyboard circuit 1 is input to the reset terminal R of the counter 16 on one side, and the envelope waveform generator 2 on the other side.
1 is entered. Here, the envelope waveform generator 21 is provided to give an appropriate volume envelope to the musical tone signal, and is used to generate a key-on signal.
It is configured to receive KON and output an envelope waveform.

The output side of the oscillator 17 which outputs the clock pulse φ ₂ is connected to the input terminal of an AND circuit 18 , and the output side of the AND circuit 18 is connected to the counting terminal Ci of the counter 16 . The carryout output terminal CA of the counter 16 is connected to the second input terminal of the AND circuit 18 via an inverter 19, and the output side of the counter 16 is further connected to the address input sides of the weight parameter memories 12-15. Here, each weight parameter memory 12~
Reference numeral 15 is a read-only memory with a small number of addresses, each of which stores different appropriate weight parameter waveforms. The output side of the weight parameter memory 12 is connected to the input terminal A of the selector 10, and the output side of the weight parameter memory 12 is connected to the input terminal A of the selector 10.
3 is connected to the input terminal B of the selector 10, the output side of the weight parameter memory 14 is connected to the input terminal A of the selector 11, and the output side of the weight parameter memory 15 is connected to the input terminal B of the selector 11.
It is connected to the. Also, as mentioned above, the comparator 9
The output side of is connected to the select command input terminal S of the selectors 10 and 11.
The output side of is connected to the respective second input terminals of multipliers 7 and 6.

Here, both selectors 10 and 11 output the signal input to the input terminal A when the logical value "0" is input to the select command input terminal S, and further output the signal input to the select command input terminal S with the logical value "1". ” is input, the signal input to input terminal B is output.

Here, weight parameter memories 12 to 15, counter 16, oscillator 17, AND circuit 18, and inverter 19 constitute weight parameter signal generation means, comparator 9 and selectors 10 and 11 constitute control means, and both The means together are referred to as a weight parameter signal generator 8.

The output side of multiplier 6 is connected to a first input terminal of adder 20 , and the output side of multiplier 7 is connected to a second input terminal of adder 20 . The output side of the adder 20 is connected to a first input terminal of a multiplier 22, and the output side of the envelope waveform generator 21 is connected to a second input terminal of the multiplier 22. The output side of the multiplier 22 is input to a sound system 23 consisting of an amplifier, speakers, etc. Note that the multipliers 6 and 7 and the adder 20 constitute a combining means.

The effects of this embodiment having the above configuration will be explained next. As mentioned above, when a certain key is pressed, the frequency information value F corresponding to this pressed key is
This frequency information value F is sequentially accumulated in an accumulator 3 at the timing of clock pulse _φ1 . This cumulative value
qF (q=1, 2, . . . ) is input as a read address signal to the waveform memories 4 and 5 on one side, and input to the input terminal A of the comparator 9 on the other side. Therefore, the waveform signals W1 and W2 are read out from the waveform memories 4 and 5.

Further, since the key-on signal KON outputted from the keyboard circuit 1 at the same time as the key is pressed is input to the reset terminal R of the counter 16, the contents of the counter 16 are sometimes set to "0" by the key-on signal KON. Therefore, at this time, the carry-out output terminal CA of the counter 16 receives the clock pulse φ ₂ output from the oscillator 17 in order to output the logic value "0".
is input to the counting input terminal Ci of the counter 16 via the AND circuit 18. The counter 16 sequentially counts this clock pulse _φ2 and outputs the counted value as a read address signal to the address input side of each weight parameter memory 12-15. Each of the weight parameter memories 12 to 15 receives the read address signal from the counter 16, and reads the weight parameter signals P _{F (t)} , P _{R (t)} , P stored in each of the weight parameter memories 12 to 15.
Output _{F (t)} and P _{R (t)} . Here, each of the weight parameter memories 12 to 15 is composed of a read-only memory with a small number of addresses as described above, and furthermore, the oscillation frequency of the clock pulse _φ2 outputted from the oscillator 17 is input to the accumulator 3. This is sufficiently lower than the oscillation frequency of clock pulse _φ1 . Therefore, the change period of the count value output by the counter 16 is sufficiently longer than the change period of the accumulated value qF output from the accumulator 3, and each weight parameter signal output from the weight parameter memories 12 to 15 P _{F (t)} , P _{R (t)} , P _{F (t)} , P _{R (t)}
The number of sample points per unit time is the waveform memory 4,
The number of sample points per unit time of the waveform signals W1 and W2 output from 5 is much smaller than that of the waveform signals W1 and W2 outputted from the waveform signals W1 and W2.

As described above, the weight parameter memory 12 to 1
Each weight parameter signal P _{F (t
)} , P _{R (t)} , P _{F (t)} , P _{R (t)} are selector 1
The signals are input to input terminals A and B of 0 and 11, respectively. Here, the comparator 9 compares the accumulated value qF inputted to the input terminal A and the constant C inputted to the input terminal B, as described above, and finds that (accumulated value qF) <
When (constant C), a logical value “0” is output, and (accumulated value
When qF)≧(constant C), a logical value “1” is output.
Further, as described above, when the logical value "0" is input to the select command input terminal S, the selectors 10 and 11 select and output the signal input to the input terminal A, and when the logical value "1" is input, When input, the signal input to input terminal B is selected and output. Therefore, if the constant C is set to, for example, 1/2 of the maximum accumulated value of the accumulator 3, the selectors 10 and 11
is the waveform signal W read out from the waveform memories 4 and 5
Different weight parameter signals P _{F (t)} , P _{F (t)} , P _{R (t)} ,
Select and output P _{R (t)} .

That is, in the state of (accumulated value qF) < constant C = 1/2 value of the maximum accumulated value of accumulator 3, comparator 9
outputs a logical value “0”. Selector 10, 11
receives this logical value "0" at the select command input terminal S, and outputs the weighting parameter signals P _{F (t)} and P _{F (t)} input to the respective input terminals A. Also, at this time, since the first half of the memory is being addressed in the waveform memories 4 and 5, the first half of one cycle of the waveform signals W1 and W2 is output from the waveform memories 4 and 5. In this way, one of the waveform signals W1 and W2 read out from the waveform memories 4 and 5
The first half of the period and the weight parameter signal P _{F (t)} ,
P _{F (t)} are multiplied by each other in multipliers 6 and 7 and output as waveform signals W1·P _{F (t)} and W2·P _{F (t)} .

As the accumulation operation of accumulator 3 progresses, (accumulation value qF)
When the constant C=1/2 of the maximum accumulated value of the accumulator 3, the comparator 9 outputs a logic value of "1". The selectors 10 and 11 receive this logical value "1" at their select command input terminals S, and output the weight parameter signals P _{R (
t)} and P _{R (t)} are output.

Further, at this time, since the second half of the memory is being addressed in the waveform memories 4 and 5, the second half of one cycle of the waveform signals W1 and W2 is output from the waveform memories 4 and 5. In this way, the waveform memory 4,
The second half of one cycle of the waveform signals W1 and W2 read from 5 and the weight parameter signals P _{R (t)} and P _R
(t) are multiplied by each other in the multipliers 6 and 7, and the waveform signals W1, P _{R (t)} ,
It is output as W2·P _{F (t)} .

As described above, when (accumulated value qF) < (constant C), the waveform signal W1·P is output from the multipliers 6 and 7.
Both _{F (t)} and W2・P _{F (t)} are input to the adder 20, where they are added together to form the waveform signal W1・P
It is output as _{F (t)} +W2・P _{F (t)} .

Subsequently, after the accumulation operation of the accumulator 3 progresses to a state where (accumulated value qF)≧(constant C), the waveform signal W1·P _{R (t )} ,
W2·P _{R (t)} are mutually input to the multiplier 20,
Here, they are added together to form the waveform signal W1・P _{R (t)}
It is output as +W2·P _{R (t)} .

Next, the above operation will be explained in detail by giving one example. Now, while the accumulator 3 performs one cycle of operation (accumulated values F, 2F, 3F...maximum accumulated value), each weight parameter signal with the following values is sent from each weight parameter memory 12 to 15. Suppose that it is output. (As mentioned above, (clock pulse _φ1 oscillation frequency)>
>(oscillation frequency of clock pulse _φ2 ), and the address movement speed of the waveform memories 4 and 5 is set sufficiently faster than the address movement speed of each weight parameter. ) P _{F (t)} = 0.5, P _{F (t)} = 1.0, P _{R (t)} = +
1.0, P _{R (t)} = 0.5 As mentioned above, the waveform memories 4 and 5 store waveforms W1 and W2 having the waveform shapes shown in FIG. Assume that it is read out as is. In this case, since the four weight parameter signals P _{F (t)} to P _{R (t)} have the above values, (cumulative value qF) < (constant C)
The waveform signal W output from the multipliers 6 and 7 in the state of
1·P _{F (t)} and W2·P _{F (t)} have waveform shapes as shown in the first half of FIG. 3A. Similarly (accumulated value
Waveform signals W1・P _{R (t)} , W2・P _{R (t) output from multipliers 6 and 7 in the state of qF)≧(constant C)}
Also, the waveform shape is as shown in the latter half of FIG. 3A. Therefore, each weight parameter signal P _{F (t)} ~P _R
When _(t) has the above value, the musical tone signal output from the adder 20 is the one shown in FIG. 3B, which is the sum of the four waveforms shown in the first half and the second half of FIG. 3A. becomes.

The waveform signal (musical tone signal) output from the adder 20 in this way is input to the first input terminal of the multiplier 22, and the second input terminal of the multiplier 22 is input from the keyboard circuit 1 to the input terminal of the multiplier 22. key-on signal generated when
The envelope waveform EV output from the envelope waveform generator 21 in response to KON is input. Therefore, the musical tone signal outputted from the adder 20 is appropriately given a volume envelope by the multiplier 22, and is then inputted to a sound system 23 consisting of an amplifier, a speaker, etc., and is produced as a musical tone.

As is clear from the above explanation, according to this embodiment, the read address signal of the waveform memory is set to the constant C.
, and according to the magnitude relationship, parameter signals of different values are sequentially multiplied within one cycle of the waveform signal output from the waveform memory, so that the waveform shape within one cycle of the musical tone signal is A musical tone signal that changes significantly can be obtained. Therefore, this electronic musical instrument can produce musical tones with a rich variety of tones.

Moreover, each of these weight parameters P _{F (t)} ~ P _{R (}
Since the value of _t) changes sequentially in accordance with the count value of the counter 16, it is possible to obtain a musical tone signal whose waveform shape constantly changes from the generation to the end of the musical tone. Furthermore, the weight parameter memory can be configured as a read-only memory with a small number of addresses.
As a result, the scale of the electronic musical instrument does not increase.

In the embodiment shown in FIG. 1, there are two waveform memories.
Although two selectors are provided corresponding to each individual waveform memory, the present invention is not limited to this, and it goes without saying that selectors may be provided as two or more waveform memories. In addition, the comparator uses the read address signal (accumulated value qF) and the constant C
However, if it is configured to compare a time-varying parameter signal and the read address signal (cumulative value qF) instead of the constant C, the rate of change in the waveform shape can be even larger. A musical tone signal can be obtained. Further, although the selector has two input terminals A and B, a selector having more weight parameter memories and two or more input terminals may be used. Furthermore, the weighting parameter signal generator of the embodiment shown in FIG. 1 uses a selector to select each weighting parameter signal read from each weighting parameter memory and outputs it.
The present invention is not limited to this; for example, a weight parameter memory to be operated may be selected by a selector.

As is clear from the above explanation, according to the present invention, without increasing the scale of the musical tone signal generator,
Since it is possible to form a musical tone signal with a large rate of change in waveform shape within one period of the musical waveform, it is possible to generate a musical tone with a large change in timbre.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIGS. 2A and B are waveform diagrams showing examples of waveforms stored in the waveform memory in the above embodiment, and FIG.
Figures A and B are waveform diagrams showing examples of waveform signals output in the above embodiment. 1...Keyboard circuit, 2...Frequency information memory, 3
... Accumulator, 4, 5 ... Waveform memory, 6, 7, 2
2... Multiplier, 9... Comparator, 10, 11... Selector, 12-15... Weight parameter memory,
16... Counter, 17... Oscillator, 20... Adder, 21... Envelope waveform generator, 23...
...sound system.

Claims (1)

[Scope of Claims] 1. Address signal generating means for generating address signals that sequentially change in accordance with desired pitches, and storing waveform signals relating to a plurality of mutually different waveforms, and generating means for generating address signals according to the address signals. a waveform storage means for reading out each waveform signal; a synthesis means for weighting and synthesizing each waveform signal output from the waveform storage means and outputting the result as a musical tone signal; and a weighting parameter for weighting each of the waveform signals. parameter signal generating means for generating a signal and applying it to the combining means; and control means for detecting that the address signal has reached a predetermined value and switching and changing the weighting parameter signal applied from the parameter signal means to the combining means. A musical tone signal generator comprising: 2. The parameter signal generation means includes a plurality of parameter memories storing respective predetermined parameter waveforms and a circuit that sequentially reads out the parameter waveforms from the memory, and the control means compares the address signal with a predetermined value. 2. The apparatus according to claim 1, comprising a comparator for determining the weighting parameter signal, and a circuit for selecting and specifying one of the parameter waveforms as the weighting parameter signal according to the comparison output of the comparator.