JPS5888792A - Electronic musical instrument - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic musical instrument that reads a musical sound waveform stored in a ROM by pressing a key, and combines it with an envelope signal to obtain a musical sound signal. The musical tone begins to decay immediately and smoothly after the key is pressed.
Furthermore, it is possible to add a trailing edge that is very similar to the trailing edge unique to natural musical instruments.

Conventionally, as a method of generating natural musical instrument sounds, a waveform for one cycle of the musical tone to be generated is stored in an FtOM, etc., the ROM is read out to generate a musical sound waveform, and an envelope is created by separately storing the waveform in advance. There is a method of multiplying and matching the signals.

In other words, the envelope waveform shown in Figure 1 is RO
When the key is pressed, the contents of the ROM are read from address 0 using an address counter, etc., and the contents are matched to the tone waveform read from another ROM. However, with this method, if you release the key and stop the address counter once the contents of address 47 are read out, the contents of address 47 in the ROM will always be output, which causes the problem that the musical tone will not decay. There is.

1. If the address counter continues to operate after the key is released, the musical tone will attenuate, but it will take a considerable amount of time from the time the key is released until the attenuation begins, making it impractical.

The present invention has been made in view of the above points, and will be explained below based on the drawings.

FIG. 2 shows one embodiment of the present invention. In FIG. 2, reference numerals 1-1 to 1-n are musical tone generators, which generate weighted sine waves. Reference numeral 2 denotes an envelope memory, which stores envelope information corresponding to a musical tone signal to be generated. In this embodiment, the contents of the envelope memory 2 consist of 128 pieces of data from address O to address 127, as shown in FIG.
Addresses 0 to 86 indicated by Kyohen 1 are the attack/attack of the musical sound.
Addresses 87 to 127 shown in section 2 of the sustain section are I
This is the JIJ-su section. 3 is a sine wave generator, which generates a sine wave signal. A multiplier 4 multiplies two input signals and outputs the result. 5 is an address control circuit which outputs a readout signal Ac to the envelope memory 2 based on a key press signal given by a key press or the like.
is sent and the envelope information is read. 6
is an adder, which adds the musical waveforms outputted from musical tone generators 1-1 to 1-n. 7 is a switching signal generator;
The key press signal also generates 1 in the open/close signal based on the readout signal Ac. 8 is a switch, and 1 is applied to the opening/closing signal.
The output of the adder 6 is opened and closed based on the . 9 is D
It is an AC (digital/analog converter).

Note that the read signal Ac sent out by the address control circuit 6
and key press signal K. The relationship between 1 and the opening/closing signal is as shown in Figure 3. That is, when the key is pressed, the key press signal also becomes "1", and the maple readout signal Ac first outputs "0", then "1", and then "2".

3. The count is sequentially counted up, but the time of key release is before and after the value of the read signal Ac reaches °'86'', that is, whether reading of section 1 in the envelope memory 2 has been completed or not. The opening/closing signal has a different value of 1 depending on whether it is open or closed.

Figure 3 (2) shows the case where the key release time is before the readout signal AaO value reaches °'86''.In other words, when the key is pressed and the key press signal also becomes 1'', the readout signal Ac is The numbers start from "o" and are counted up sequentially. Next, when the key is released, the key press signals become "P○", but the read signal Ac is counted up sequentially.

Then, when the key is pressed again, the read signal Ac becomes I
After being reset to t071, the count is sequentially increased.

On the other hand, if the open/close signal is 1, the read signal Ac is “on”.
At the same time, it rises to its maximum value, and the key press signal K
. When becomes "o", it decays exponentially.

FIG. 3(B) shows the case where the key is continued to be pressed even after the value of the readout signal Ac reaches "86", and the key is released after a while. In other words, the readout signal Ac becomes "86". If the key continues to be pressed even after the key is pressed, the value of the read signal Ac stops at 86'', and is counted up again after *key. If there is no new key pressed after the key is released, the value of the read signal Ac counts up to 127'' and then stops.

On the other hand, 1 in the interval close signal is the readout signal Ac at the same time as the key is pressed.
It rises to its maximum value in synchronization with the key, but it always maintains a constant value without falling even after the key is released.

In addition, in the above embodiment, musical tone generators 1-1 to 1-n
All have the same configuration, but the contents stored in the envelope memory 2 and the frequency of the generated sine wave signal are different, and the frequency of the sine wave signal is different from the signal frequency l of the reference sine wave generator. They are integral multiples of each other, that is, they have a harmonic relationship.

Next, the operation of the embodiment shown in FIG. 2 will be explained with reference to FIG. 4. In order to simplify the explanation, only the signal output from the musical tone generator 1-1 will be described here.

When the key press signal also rises due to the key press, Fig. 3 (6), (
As shown in B), the address control circuit 6 receives the read signal A.
c to the envelope memory 2, and the switching signal generator 7 sends the switching signal 1 to the switch 8, respectively. As a result, the envelope memory lJ2 outputs an envelope signal based on the read signal Ac without being switched (Fig. 4A).
. On the other hand, the sine wave generator 3 outputs a sine wave signal, this sine wave signal is multiplied by the aforementioned envelope signal in the multiplier 4, and is output from the tone generator 1-1. Similarly, the other musical tone generators 1-n output sine wave signals multiplied by envelope signals and added together by an adder 6. At this time, as mentioned above, since the frequencies of the signals output from each musical tone generator 1-1 to 1-n are in a harmonic relationship, the output of the adder 6 has a plurality of harmonics having independent envelopes. It becomes a sine wave composite.

On the other hand, since the key press signal also becomes 1", the open/close signal rises to 1 as shown in FIG. 3 (FIG. 4B).

In response to this switching signal, the switch 8 sends the output of the adder 6 to the DAC 9 without attenuating it (see Fig. 4C).
0≦t≦τ). Next, when the key is released at t-τ, the key press signal also becomes 0''.At this point, the address control circuit 5
outputs °'53", which is the result of "
Since it is smaller than 86", 1 starts to attenuate in the open/close signal (
Figure 4B, t) τ). Therefore, the output of the switch 8 attenuates as the switching signal increases by 1 (t>τ in FIG. 4C). Similarly, the output signals of the other tone generators 1-n are attenuated by the switch 8.

As described above, since the musical tone signal attenuates at the same time as the key is released, the problem of continuing to output the contents of the ROM at the address at the time of the key release can be solved.

Also, if the time that the key is pressed is long enough, the third
As mentioned in the figure, the read signal Ac stops at 86",
The count amplifier starts at the same time as the key is released. As soon as this happens, the envelope memory 2 is read out from address 87 onward, that is, the release part of section 2, and the musical tone begins to decay at the same time as the key is released.

As described above, according to the above embodiment, the musical tone signal can be attenuated quickly and smoothly when the key is released, regardless of the length of time the key is pressed.

In the above embodiment, the opening/closing signal generator 7 generates an opening/closing signal that decays exponentially. It goes without saying that if this is done, it is possible to generate musical tones that are even closer to those of natural musical instruments. However, instead of the sine wave generator 3, a waveform generator that repeatedly generates one waveform of a musical tone may be used.

FIG. 6 shows another embodiment of the invention.

In FIG. 6, parts having the same functions as those in FIG. 2 are designated by the same reference numerals, and detailed explanations will be omitted. 10
is a three-man multiplier.

Next, the operation shown in FIG. 6 will be explained. Since the basic operation is the same as that of the circuit shown in FIG. 2, the explanation will be given using FIG. 4 as in the case of FIG. 2.

A key press signal K is generated by pressing a key. When it rises, Figure 3 (~, (
As shown in B), the address control circuit 6 receives the read signal A.
c, the switching signal generator γ sends 1 as the switching signal.

As a result, first, the envelope memory 2 outputs an envelope signal based on the read signal Ac (Fig. 4A
), while the sine wave generator 3 outputs a sine wave signal. Further, when the key press signal becomes "1", 1 rises in the open/close signal as shown in FIG. 3 (FIG. 4B). This opening/closing signal is multiplied by 1, the aforementioned sine wave signal, and an envelope signal. Similarly, in the other musical tone generators I n, the envelope signal, the sine wave signal, and the opening/closing signal are multiplied by 1 and the resulting outputs are added together by the adder 6. Here again, as mentioned above, the frequencies of the signals output from each musical tone generator 1-1 to 1-n are in a harmonic relationship, so the output of the adder 6 has a plurality of harmonics having independent envelopes. It becomes a sine wave composite.

Considering the output of the multiplier 10 here, while the key is pressed (Fig. 4) ≦t≦τ), the open/close signal is 1.
In order to continue outputting the maximum value, it outputs a signal equivalent to the signal obtained by multiplying the output of the envelope memory 2 by a sine wave. Then, when the key is released at t-τ, the key press signal also becomes II OII.

At this point, the address control circuit 5 is outputting "53", which is smaller than 86" mentioned in FIG.
1 in the opening/closing signal begins to attenuate (Bt>τ in FIG. 4). Therefore, the output of the multiplier 10, which is the sum of the envelope signal, sine wave, and open/close signal multiplied by 1, also attenuates and closes (C, t in Figure 4).
τ).

As described above, since the musical tone signal attenuates at the same time as the key is released, in this embodiment as well, when the key is released, the ft0M of the address at the time of the key release is
This solves the problem of continuously outputting the contents of .

Also, if the time that the key is pressed is long enough, the third
As mentioned in the figure, the read signal Ac stops at 86",
The count-up starts as soon as you release the key. Therefore, from envelope memory 2 to address 87 onwards, that is, IJ in section 2.
Upon reading out the IJ-space section, the output of the multiplier 10 begins to attenuate at the same time as the key is released.

As described above, in the embodiment shown in FIG. 6 as well, the musical tone signal can be attenuated quickly and smoothly when the key is released, regardless of the length of time the key is pressed.

In the embodiment shown in FIG. 5, each musical tone generator 1-1 to
1-n, since 1 can be arbitrarily selected for the switching signal generated by each switching signal generator 7, the DAC
The falling edge of the musical tone signal outputted from 9 can be made to be very similar to that of a natural musical instrument.

FIG. 6 shows an improved version of the multiplier 10 in FIG. In FIG. 6, 11 is an adder.

A converter 12 performs logarithmic/linear conversion.

When using the multiplier shown in FIG. 6, 1 is converted into a logarithm in advance for the envelope signal and the opening/closing signal. Immediately,
The envelope memory 2 stores envelope information in logarithmic representation, and the opening/closing signal generator 7 also outputs the opening/closing signal in logarithmic representation. By using such a multiplier 10, calculation time can be saved.

In the above description, the opening/closing signal generator 7 may be of any type as long as it generates a signal as shown in FIG. 3, and an example thereof is shown in FIG. 7. In FIG. 7, 13 is a comparator, and address control circuit 6
A comparison is made between the read signal Ac generated by the signal Ac and a predetermined value, which in the above embodiment is ``86'', and outputs 1'' when C1≦86 to the read signal.
A latch 4 latches the signal applied to the D terminal at the rising edge of the CK terminal and outputs it from the Q terminal. 15 is a clock generator. 16 is a 6-bit counter, which counts the signal applied to the CK terminal. Further, when the signal applied to the R terminal becomes 1', the output is unconditionally reset.

Reference numeral 17 denotes a memory, which has 32 pieces of information from addresses O to 31, and stores information to be output as opening/closing signals. The contents of the memory 17 are as shown in FIG.

Next, the operation of the switching signal generator shown in FIG. 7 will be explained.

First, when the key press signals become "1" due to a key press, the R terminal of the counter 16 becomes "1", so all counter outputs are reset to 0. Therefore, while the key is being pressed, the O address of the memory 17 is The content of is always output.Next, when the key press signals become "0" due to key release, the input signal of the CK terminal of the latch 14 rises due to the inverter 18, and the comparator 1
The output of 3 is latched. Therefore, 1 read signal Ac1)
At the time of 860, the output of the latch 14 becomes "0", and when the 1 read signal Aci≦86, the output of the latch 14 becomes "1".

1 read signal Ac1)se, the output of the latch 14 is "o"', so the output of the AND circuit 19 is always "o"'.
o'', and the counter 16 is stopped in the reset state.Therefore, the contents of memory address 1700 are output, and the output of the open/close signal generator 7 does not change even when the key is released.

On the other hand, when the 1 read signal Acl≦86, the output of the latch 14 is 1'''. Since the counter 16 has been reset, the output of the AND circuit 20 is also 1'.
”. Therefore, the AND circuit 19 is the clock generator 15
The clock signal generated by the counter 16 is output, and the CK of the counter 16 is
Give it to the terminal. After the key is released, the input signal to the R terminal of the counter 16 is "o", so the counter 16 starts counting the clock signal applied to the CK terminal and outputs it to the memory 17. The memory 17 sequentially reads and outputs the memory contents based on the output of the counter 16. memory 1
Since the contents of 7 are as shown in FIG. 8, the output of the switching signal generator 7 gradually attenuates. Here counter 1
6 continues to count the clock signal, and when all 5-bit outputs become "1", that is, when the last content of the memory 17 is read out, the output of the N and AND circuit 2o becomes "o".
”, and the output of the AND circuit 19 also becomes “O”. Therefore, the clock signal is no longer applied to the CK terminal of the counter 16, and the counter 16 stops with the output indicating “31”. As a result, the memory 17 outputs the contents of address 31 up to the new key press.

The above is the operation of the switching signal generator 7 shown in FIG. When the opening/closing signal generator 7 is configured as shown in FIG. 7, it is possible to provide various musical tones with various falling edges depending on the contents stored in the memory 17, and this can be done extremely easily.

FIG. 9 shows an embodiment in which an envelope memory 2 and an interpolation circuit 21 are used in place of the envelope memory 2 in FIGS. 2 and 5.

Next, the operation shown in FIG. 9 will be explained together with the output waveforms of the envelope memory 2 and interpolation circuit 21 shown in FIG. 10.

The address control circuit 6 outputs the read signal A based on the key press signal.
The operations from generating the signal c to reading the envelope information from the envelope memory 2 are the same as those shown in FIGS. 2 and 6. When the envelope memory 2 outputs envelope signals at time intervals as shown in FIG. 10(a), the interpolation circuit 21
replenishes the envelope signal at intervals of τ/4. In this way, the frequency of the clock signal can be lowered, and the capacity of the envelope memory can be reduced.

It goes without saying that the circuit shown in FIG. 9 may be applied to the memory 17 in FIG.

Further, in the above embodiments, a case has been described in which a single musical tone is generated, but it is not impossible to generate multiple tones by using envelope memories, multipliers, etc. in a time-sharing manner.

As described above, according to the present invention, the musical tone starts to decay immediately and smoothly after the key is released, regardless of how long the key is held down, and the decay is very similar to the decay characteristic of natural musical instruments. The excellent effect of being able to add

[Brief explanation of the drawing]

Fig. 1 is a diagram showing envelope information stored in a general envelope memory, Fig. 2 is a block diagram showing an embodiment of an electronic musical instrument according to the present invention, and Fig. 3 is a diagram showing key press signals, readout signals, opening/closing signals, etc. 4 is a diagram showing the relationship between the envelope signal, opening/closing signal, switch output, and key press signal. FIG. 6 is a block diagram showing another embodiment of the present invention. Fig. 5 is a diagram showing an example of the multiplier, Fig. 7 is a diagram showing an example of the switching signal generator, Fig. 8 is a diagram showing the contents stored in memory, and Fig. 9 is an interpolation calculation of envelope information. FIG. 10 is an output waveform diagram of the interpolation circuit shown in FIG. 9. 1-1 to 1-n...musical tone generator, 2...
・Envelope memory, 3...Sine wave generator,
4... Multiplier, 5... Address control circuit, 6... Adder, 7... Switching signal generator, 8... Switch, 1o... Power comparator, 14... Laso-F-115...
・Clock generator, 16... Counter, 17...
...Memory, 21...Interpolation circuit. Name of agent: Patent attorney Toshio Nakao, and one other person, Tomo Kama;

Claims (1)

[Scope of Claims] (1) A waveform generator that generates a musical sound waveform, an envelope storage device that stores envelope information, and an envelope signal that is generated based on the musical sound waveform and the envelope information. an address control device that generates a readout signal to read out the contents of the envelope storage device based on a key press signal generated by key press and release; and an open/close signal generator that generates different open/close signals, the electronic musical instrument comprising: an open/close signal generator that generates different open/close signals, and the output of the arithmetic unit is opened/closed based on the open/close signal. (2. An electronic musical instrument as set forth in claim 1, characterized in that the opening/closing signal generator generates an opening/closing signal that gradually attenuates the output of the arithmetic unit immediately after the key is released. ( 3) In the statement of claim 2, it is stated that the opening/closing signal generator generates the opening/closing signal that causes the output of the arithmetic unit to be output without attenuation until a certain period of time has passed after the key is pressed. An electronic musical instrument characterized by: (4) In the description of claim 1, 1. A plurality of sets of musical tone generators each including a waveform generator, an envelope storage device, and an arithmetic unit; An electronic musical instrument characterized in that an arithmetic unit is constituted by an adder that adds the outputs of the arithmetic unit of the musical tone generator, and the output of the adder is opened and closed by an opening/closing signal. In the description of scope 4, each waveform generator in the plurality of musical tone generators is configured with a sine wave generator,
An electronic musical instrument characterized in that the frequency of a sine wave signal generated by each waveform generator is substantially an integral multiple of the frequency of a sine wave signal outputted from a waveform generator serving as a reference. (6) a waveform generator that generates a musical sound waveform, an envelope storage device that stores envelope information, and an open/close signal generator that generates an open/close signal based on a key press signal generated by key press and release; The present invention is characterized by comprising a computing unit that computes the musical sound waveform, the envelope information, and the opening/closing signal, and an address control device that generates a readout signal to read out the contents of the envelope storage device based on the key press signal. electronic musical instruments. (7) In the statement of claim 6, the opening/closing signal generator causes the arithmetic unit to output the product of musical tone generation and envelope information from the time of key depression to the time of key release; An electronic musical instrument characterized by transmitting an opening/closing signal that gradually attenuates the output of an electronic musical instrument. (8) In the statement of claim 7, the opening/closing signal generator generates the opening/closing signal such that the output of the arithmetic unit becomes substantially equal to the musical waveform and the envelope signal until a certain period of time has elapsed after the key is pressed. An electronic musical instrument characterized by the ability to transmit.