JPS645718B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic electronic sound performance device that can be used, for example, as an electronic music box.

This type of automatic musical performance device has already been put into practical use as a melody generating IC. In this method, melody information such as pitch and length of notes is stored in read-only memory in advance, and the output pulse of the oscillator is divided by a programmable frequency divider according to this data, resulting in a frequency corresponding to each note. It generates an alternating current voltage waveform, and it is possible to play the main melody scale and the accompaniment scale at the same time. Therefore, the melody information memory stores reset signals for the scale, note length, and envelope for each note, which has the disadvantage that the number of bits in the memory increases.

FIG. 1 shows a part of the melody memory of the above-mentioned conventional IC-based automatic electronic sound performance device, in which 4 bits, half notes, and quarter notes are used for setting the main melody scale and accompaniment scale, respectively. , 2 bits for setting the length of notes corresponding to eighth notes, etc., and 1 bit each for presetting the envelope of the main melody and accompaniment, for a total of 12 bits.The entire melody memory has 12 x n bits. One, two, or more songs can be stored within this range.

By the way, as is clear from Figure 1,
It can be seen that the envelope is reset faithfully for each note. However, when such a melody generating IC is used in an electronic music box, it is not necessarily desirable to faithfully reset the envelope for each note. This is because the sound of an electronic music box is a simulated version of the sound of a mechanical music box, but once the vibration valve of a mechanical music box has been played, there is no way to actively stop the vibration. Even though the rest has no meaning until the end, if you reset it in the middle of the envelope, you will not be able to produce a natural music box sound. To explain this further with reference to Fig. 3, the curves shown in Fig. 3 all show the envelope of a mechanical music box. In each case, the melody is not stopped in the middle, but in the conventional melody generation IC, the melody is generated at each time corresponding to each note.
A break in the middle of the envelope will cause the envelope to be reset (ie, the envelope will be restarted from the initial position). This third
As is clear from the figure, the conventional melody generation IC
is not very desirable for use in electronic music boxes.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic performance device for electronic sounds that can reduce the number of bits in a melody memory.

Another object of the present invention is to provide an automatic electronic sound performance device that can produce sounds extremely similar to natural music box sounds.

The feature of the present invention is that in a music box, a rest has no meaning until the end of the envelope, and this is applied to a circuit, as shown in Figure 2.
When the tonic scale and accompaniment have different note lengths, this address is used as a rest in memory for the longer one, and the rest maintains its previous state in operation, that is, the envelope continues in the same scale. There is a particular thing.

According to the present invention, it is necessary to add first and second gate circuits and first and second latch circuits;
This has the effect of saving 2×n bits of memory for tone length setting. Moreover, while the gate circuit and latch circuit described above have extremely simple configurations, the ability to save 2×n bits of memory is extremely advantageous in terms of space efficiency. This greatly contributes to miniaturization and cost reduction.

Furthermore, since the sound is not stopped in the middle of the envelope, it is possible to obtain a natural melody that closely resembles the sound of a music box.

The present invention will be described below with reference to FIGS. 4 to 6.

In FIG. 4, control circuit 1 is connected to terminal 2.
The oscillation circuit 3, the tempo memory 5 in the tempo/rhythm setting section 11, and the address counter 7 are controlled by a start signal input from the oscillation circuit 3, respectively. The constant frequency signal output by the oscillation circuit 3 is once divided by a predetermined frequency division ratio by the frequency dividing circuit 4, and then divided by the programmable frequency divider 14 in the main melody scale setting section 12 and the accompaniment scale setting section. The signal is input to a programmable frequency divider 15 in the 13 and a programmable frequency divider 6 in the tempo and rhythm setting section 11, respectively. The tempo memory 5 in the tempo/rhythm setting unit 11 reads out a preset storage signal based on the control signal from the control circuit 1, and determines the frequency division ratio of the programmable frequency divider 6. The output of the programmable frequency divider 6 is input to another programmable frequency divider 10 in the tempo/rhythm setting section 11, and the output of the latter frequency divider 10 is input to the address counter 7, the first gate circuit 16, and the first gate circuit 16. 2 gate circuit 1
7. They are each input to the control circuit 1. Address counter 7 is frequency divider 1
The tone length signals stored in the melody memory 8 are sequentially read word by word by stepping based on the signal from 0. The signal from the melody memory 8 is input to the rhythm decoder memory 9 in the tempo/rhythm setting section 11, and the memory 9 sets the division ratio of the programmable frequency divider based on the note length signal from the melody memory 8. It's getting old.

The main melody signal read out by the melody memory 8 is transmitted through the first gate circuit 16 and the first latch circuit 18.
The accompaniment signal input to the melody memory 8 and read out by the melody memory 8 is sent to the second gate circuit 17 and the second gate circuit 17.
The signal is input to the latch circuit 19 and the control circuit 1. The first gate circuit 16 outputs a signal when a signal from the tempo/rhythm setting section 11, that is, a signal synchronized with the input signal of the address counter 7, and a signal from the melody memory 8 are input, and the first latch is closed. The main melody signal from the melody memory 8 is temporarily stored in the circuit 18, and the main melody envelope adding circuit 22 is reset. Further, the second gate circuit 17 outputs a signal when a signal synchronized with the input signal of the address counter 7 and a signal from the melody memory 8 are inputted to the second latch circuit 1.
9 temporarily stores the accompaniment signal from the melody memory 8, and also resets the accompaniment envelope adding circuit 23. The output of the latch circuit 18 is input to the main melody scale decoder memory 20 in the main melody scale setting section 12, and the latch circuit 18 outputs a signal corresponding to the temporarily stored main melody signal to divide the frequency of the programmable frequency divider 14. After determining the ratio, the frequency divider 14 outputs a signal of a frequency corresponding to the scale. Similarly, the output of the second latch circuit 19 is the accompaniment scale decoder memory 2 in the accompaniment scale setting section 13.
1 and outputs a signal corresponding to the accompaniment signal temporarily stored in the latch circuit 19 to determine the frequency division ratio of the programmable frequency divider 15. It is designed to output a signal of the corresponding frequency. The main melody scale signal from the programmable frequency divider 14 and the accompaniment scale signal from the programmable frequency divider 15 are enveloped by a first envelope addition circuit 22 and a second envelope addition circuit 23, respectively, and then sent to a mixer 24. The signals are mixed together, amplified by an amplifier 25, and emitted from a speaker 26 as an audible sound wave signal.

FIG. 5 shows a specific example of the first gate circuit 16 and the second gate circuit 17, and these gate circuits are respectively an OR circuit OR and an AND circuit which takes the output of this OR circuit as one of its inputs.
It is constructed by AND. If this gate circuit is the first gate circuit 16, then
A 4-bit signal for storing the main melody scale in the melody memory 8 is input to the OR circuit OR. Further, a signal synchronized with the input signal of the address counter 7 described above is input to the other input terminal of the AND circuit AND. Now, considering that at least one of the four bits for storing the main melody scale in melody memory 8 is set to "1", and therefore a note signal other than a rest is output, the OR circuit The output of OR will be "1". Since a signal of "1" is added to the other input terminal of the AND circuit AND every time a note signal other than a rest is switched, a signal of "1" is added from the AND circuit AND every time a note signal other than a rest is switched. A signal of "1" will be output. This signal becomes the output signal of the gate circuit 16 to activate the latch circuit 18 and also reset the envelope addition circuit 22.

FIG. 6 shows the relationship between the allocation of each bit in the melody memory 8 and the external circuit. In FIG. 6, among the stored bits in the melody memory 8, 2 bits are used to set the tone length corresponding to each note, that is, the rhythm, 4 bits are used to set the main melody scale, and the other 4 bits are used to set the accompaniment scale. It is used for settings. Then, the 2-bit signal for rhythm setting is added to the rhythm decoder memory 9, the 4-bit signal for the main melody scale is temporarily stored by the latch circuit 18, and then added to the main melody scale decoder memory 20, and the 4-bit signal for the main melody scale is added to the main melody scale decoder memory 20. The 4-bit signal is temporarily stored by a latch circuit 19 and then added to an accompaniment scale decoder memory 21. The two bits for envelope presetting indicated by dotted lines in FIG. This shows that it has nothing to do with bits.

Next, the operation of the above embodiment will be explained. When a start signal is input to the control circuit 1 from the terminal 2 by operating the start button, the control circuit 1 operates the oscillation circuit 3 and inputs the signal to the tempo memory 5 and the address counter 7. The output of the oscillation circuit 3 is divided into a signal of a predetermined frequency by a frequency dividing circuit 4, which includes a programmable frequency divider 6 in the tempo and rhythm setting section 11, a programmable frequency divider 14 in the main melody scale setting section 12, Each of the signals is input as a reference frequency signal to the programmable frequency divider 15 in the accompaniment scale setting section 13. The tempo memory 5 stores a tempo signal corresponding to the song in advance, reads this out according to the signal from the control circuit 1, and sends the tempo signal to the programmable frequency divider 6.
A frequency division ratio is determined, and a signal of a predetermined frequency is outputted from the frequency divider 6 and inputted to the rhythm programmable frequency divider 10. Further, the address counter 7 reads out the first stored signal in the melody memory 8 based on the signal from the control circuit 1,
Among them, the tone length signal is input to the rhythm decoder memory 9. The rhythm decoder memory 9 outputs a signal corresponding to the signal from the melody memory 8 to determine the frequency division ratio of the programmable frequency divider 10, and then,
The frequency divider 10 outputs a signal with a width commensurate with a predetermined tone length. This output signal is input to the address counter 7. The counter 7 increments each time a signal is inputted from the frequency divider 10 to the melody memory 8.
Advance one word at a time. Therefore, the frequency division ratio of the programmable frequency divider 10 is reset each time by the rhythm decoder memory 9, and the rhythm is then set.

On the other hand, the main melody scale signal read from the melody memory 8 is input to the first gate circuit 16 and the first latch circuit 18. A signal synchronized with the input signal of the address counter 7, that is, a tempo signal from the programmable frequency divider 10 in the tempo/rhythm setting section 11 is also input to the first gate circuit. Therefore, the signal from the memory 8 and the signal from the programmable division period 10 are synchronized, and if the signal from the memory 8 is a note signal other than a rest, the gate circuit 16 outputs a signal of "1". The first latch circuit 18 is activated and the envelope addition circuit 22 is reset. The latch circuit 18 temporarily stores the main melody scale signal from the melody memory 8 according to the signal from the gate circuit 16, and
This stored signal is input to the decoder memory 20 in the main melody scale setting section 12. The decoder memory 20 outputs a signal corresponding to the main melody scale signal, sets the frequency division ratio of the programmable frequency divider 14, and causes the frequency divider 14 to output a signal with a frequency corresponding to the actual scale. An envelope is added to the signal from the frequency divider 14 by the envelope adding circuit 22, which is reset by the "1" signal from the gate circuit 16, and the mixer 24 and the amplifier 2
The actual sound is emitted from the speaker 26 via 5. As the address counter 7 increments, the readout signal of the melody memory 8 advances one word at a time. If this signal is a musical note signal, the gate circuit 16 outputs a signal of "1" again.
When the latch circuit 18 is latched again, the envelope adding circuit 22 is reset, and the envelope is added to the switched note signal again from the beginning. However, if the next read signal from the melody memory 8 is a rest signal, all four bits for the main melody scale of the melody memory 8 are "0", so the output of the gate circuit 16 is "0", and the latch is Circuit 18 remains latched to the previous scale signal, and envelope addition circuit 22 is not reset. Therefore, in this case, the envelope continues as it is in the previous scale, and as long as no note signal is input to the gate circuit 16, it will continue to attenuate. Also, as shown in Figure 2, when there is a difference in note length between the main melody scale and the accompaniment scale, the longer note length is ``Γ'' in the same way as a rest.
ΓΓΓ'', the envelope will continue as is, just like in the case of a rest. Therefore, when the note length is long and when there is a rest, the sound is the same, but there is no difference in the actual melody, and when using this as an electronic music box, the sound is similar to that of a mechanical music box. Since it is extremely similar, it is rather suitable as an automatic performance device for an electronic music box.

The accompaniment scale signal read from the melody memory 8 is also input to the second gate circuit 17 and the second latch circuit 19, a predetermined accompaniment scale is set by the accompaniment scale setting section 13, and a second envelope is added. An envelope is added by the circuit 23, but since these operations are the same as in the case of the main melody scale, a detailed explanation will be omitted.

The present invention is not limited to the configuration of the illustrated embodiment, and the following modifications are possible.

(1) The latch circuit is provided to prevent the previous signal from changing when the output of the programmable frequency divider that is output to the envelope addition circuit is a rest signal, so the connection between this programmable frequency divider and the melody memory is It may be placed anywhere in between. Further, it may be provided together with the decoder memory.

(2) The signal synchronized with the input signal of the address counter 7 that enters the AND gate in each gate circuit may be the output signal of the address counter since it can be a pulse that is output when the address is advanced.

(3) It is preferable for the input signal to the gate circuit to be input from the melody memory somewhat in advance (in the opposite case, the latch operation will not be performed smoothly).
Therefore, for example, it is effective to first output a word advance signal from the address counter to the melody memory, and then output a pulse to the gate circuit. In the example shown in FIG. 5, the timing of the signal input to one input terminal of the AND circuit may be adjusted using a delay circuit or the like.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a melody memory in a conventional device, FIG. 2 is an explanatory diagram showing an example of a melody memory in the device of the present invention, FIG. 3 is a diagram showing an example of an envelope, and FIG. A block diagram showing an embodiment of the present invention, FIG. 5 is a block diagram showing the configuration of a gate circuit in the embodiment, and FIG. 6 is an explanation showing the relationship between the melody memory and its related circuitry in the embodiment. It is a diagram. 1... Control circuit, 3... Oscillator circuit, 5... Tempo memory, 6, 10, 14, 15... Programmable frequency divider, 7... Address counter, 8... Melody memory, 9... Rhythm decoder memory, 11... Tempo, rhythm setting Part 12...Main melody scale setting part,
13... Accompaniment scale setting section, 16... First gate circuit,
17...Second gate circuit, 18...First latch circuit,
19... Second latch circuit, 20... Main melody scale decoder memory, 21... Accompaniment scale decoder memory, 2
2, 23...Envelope addition circuit.

Claims (1)

[Scope of Claims] 1. An oscillator that serves as a reference for tempo, rhythm, and scale; a storage unit for storing main melody scales, accompaniment scales, etc.; , a tempo and rhythm setting section for setting the rhythm, an address counter that operates with the output of this setting section and increments the memory word in the storage section, and a main melody scale setting section and an accompaniment scale setting section that operate on the output of the storage section. and a first envelope adding circuit and a second envelope adding circuit that add envelopes to the outputs of the main melody scale setting section and the accompaniment scale setting section, A first latch circuit that temporarily stores the scale output, a second latch circuit that temporarily stores the accompaniment scale output of the storage section, and a signal synchronized with the address counter and the main melody scale output of the storage section. input, and only when the main melody scale output is a note signal other than a rest, the main melody scale output is temporarily stored in the first latch circuit, and the first envelope addition circuit is reset, so that the main melody scale output is a rest signal. In this case, the first gate circuit keeps the previous scale output stored in the first latch circuit and does not reset the first envelope addition circuit, and the signal synchronized with the address counter and the accompaniment scale in the storage section. output is input, and only when this accompaniment scale output is a note signal other than a rest, the accompaniment scale output is temporarily stored in the second latch circuit, and the second envelope addition circuit is reset, so that the accompaniment scale output is and a second gate circuit that keeps the previous scale output stored in the second latch circuit when it is a rest signal and does not reset the second envelope addition circuit, and the main melody scale setting section , the main melody scale output input to the first latch circuit and temporarily stored is inputted, and a signal of a frequency corresponding to the scale is inputted to the first envelope addition circuit; 1. An automatic performance device for electronic sounds, characterized in that an accompaniment scale output input and temporarily stored is inputted to a second envelope adding circuit, and a signal of a frequency corresponding to the scale is inputted to a second envelope adding circuit.