JPH0137759B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to electronic musical instruments, and more specifically, to musical tones that are given pitch modulation effects such as vibrato effects by changing the pitch of musical tones temporarily or at a predetermined repetition period. Regarding electronic musical instruments that generate

[Conventional technology]

In electronic musical instruments, pitch modulation effects such as vibrato, attack pitch, glide, and pitch bend effects are created by changing the pitch (frequency) of a musical tone signal from a normal pitch temporarily or at a predetermined repetition period. Generating musical tones is performed.

In order to generate musical tones with such a pitch modulation effect, conventional methods have been used, for example,
As shown in Publication No. 37031, pitch modulation information (vibrato control signal) whose value changes sequentially over time is generated, and this pitch modulation information provides regular pitch information corresponding to the pitch of the pressed key. (frequency information) and designates the phase of each sample point of the musical tone signal in accordance with the modulated pitch information to generate a musical tone signal.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, since the pitch modulation information changes at an independent timing that is completely unrelated to the period of the musical tone signal being generated, there is a situation where the value of the pitch modulation information suddenly changes in the middle of one period of the musical tone signal. As a result, the interval between each sample point of the musical tone signal changes within one period of the musical tone signal, resulting in the inconvenience that noise is generated.

The present invention has been made in view of these drawbacks, and its object is to provide an electronic musical instrument that can generate musical tones with pitch modulation effects such as vibrato effects without producing noise.

[Means and actions for solving problems]

This invention prevents pitch information modulated by pitch modulation information from changing during one cycle of a musical tone signal and maintains the same content, and allows the pitch information to change in synchronization with the end of the one cycle. A control means is provided to
The intervals between each sample point in one cycle of the musical tone signal are set at equal intervals.

〔Example〕

Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a block diagram showing one embodiment of the present invention. In the figure, a keyboard circuit 1 includes a plurality of performance keys, and one or more keys pressed here are detected by a key press detection circuit 2.
When the pressed key detection circuit 2 detects one or more pressed keys, it outputs a key code KC corresponding to each of these pressed keys and supplies it to the sound generation assignment circuit 3.

The pronunciation assignment circuit 3 assigns the key code KC corresponding to each pressed key to a plurality of pronunciation channels corresponding to the number of simultaneous pronunciations, for example, 12 pronunciation channels.
A musical tone signal of a pitch corresponding to the pressed key is generated in this assigned channel in proportion to any one of CH1 to CH12, and the sound generation channels CH1 to CH12 in this embodiment are a common musical tone signal generation circuit system. The key code KC assigned to each channel is outputted in a time-division manner at a timing corresponding to the assigned channel. At this time, along with the key code KC, a key-on signal that intermits, for example, a "1" signal while the key is being pressed.
KON is time-divisionally output for each sound channel.

The key code KC for each sound generation channel thus output is input to the frequency information generating circuit 4. The frequency information generation circuit 4 generates frequency information (reference pitch information) F that determines the reference pitch of the musical tone signal to be generated, and is supplied with the key code KC assigned to each sound generation channel from the sound generation assignment circuit 3. Then, frequency information F corresponding to this key code KC is time-divisionally output in the same way as the key code KC. This frequency information F is input to a multiplier 5, where it is multiplied by vibrato control information (pitch modulation information) VS' for a vibrato effect supplied from a time division latch 6, and thereby changed. The changed frequency information F' is then supplied to the frequency counter 7, where it is accumulated at a predetermined period. As a result, the cumulative value qF' (q=1, 2,
) is formed, and this accumulated value qF' is a phase signal x that specifies the sample point phase of the musical tone signal to be generated.
is output as

This phase signal x is supplied as a read address signal to a tone waveform memory 8 that stores waveform amplitude values (sample point amplitude values) of a plurality of sample point phases in one cycle of a desired tone waveform. As a result, each sample point amplitude value is read out from the musical waveform memory 8 at a repetition period corresponding to the phase signal x.

This sample point amplitude value is input to the volume control circuit 9 as a musical tone signal. Here, an envelope signal EV is generated from the envelope generation circuit 10 which starts operating in response to the key-on signal KON.
After receiving amplitude control from the sound system 11, the sound system 11 generates musical tones.

The multiplier 5, time-division latch 6, frequency counter 7, musical waveform memory 8, volume control circuit 9, and envelope generation circuit 10 are all time-divisionally operated in correspondence with the 12 time-division sound channels CH1 to CH12. operates to form musical tone signals in each sound generation channel.

By the way, the vibrato control information VS for the vibrato effect is generated from the vibrato control information generation circuit 12 for each sound channel in synchronization with the rise of the key-on signal KON, but when the vibrato control information VS for each sound channel is latched. As shown in a specific example in FIG. 2, the division latch 6 includes a shift register 60 having 12 storage positions (stages) corresponding to sound generation channels CH1 to CH12, and vibrato control information VS generated from the circuit 12. and a selector 61 that selectively supplies the output information VS' of the shift register 60 to the input side storage location of the shift register 60.
As a selection control signal for the selector 61, a cycle signal CY which becomes "1" at the start of one period of the musical tone signal is supplied from the frequency counter 7, and the selector 61 is activated only at the beginning of one period of the musical tone signal. Vibrato control information from circuit 12
Select VS and shift register 6 for the rest of the time
It is configured to select output information VS′ of 0.

In this case, the cycle signal CY is generated for each sound channel in synchronization with the repetition period of the phase signal x, as shown in the time chart in Figure 3 (when the phase signal x returns from the final value to the initial value) ).

Therefore, at the timing corresponding to the n-th sound channel CHn, the vibrato control information of the n-th sound channel CHn is transferred from the shift register 60.
VS' is output and fed back to the A-side input of the selector 61. At this time, when the cycle signal CY becomes "1", vibrato control at a new time of the n-th sound channel CHn input to the B-side input is performed. Information VS
is selected and taken into the shift register 60. Then, this vibrato control information VS is applied to A of the selector 61 until the next new cycle signal CY is generated for the nth sounding channel CHn.
Memory is maintained by a feedback loop via the side input.

As a result, the vibrato control information VS' input to the multiplier 5 will not be changed until one period of the musical waveform is completed, so the changed frequency information F' output from the multiplier 5 will remain unchanged during one period of the musical waveform. Retained at the same value. As a result, the rate of change of the phase signal x output from the frequency counter 7 is constant during one cycle of the musical sound waveform, so that the phase intervals of each sample point of one cycle of the musical sound waveform are equal, and There is no sudden change in the phase interval between sample points in the middle of a cycle, and noise generation is prevented.

Incidentally, instead of using a shift register as the time division latch 6, as shown in another embodiment of FIG.
Latch circuits 64-1 to 64-12 and AND gates 65-1 to 65-12 respectively corresponding to the sound generation channels CH1 to CH12 are provided, and channel signals representing the time division timing of each sound generation channel are provided.
The AND signal of CH1 to CH12 and the cycle signal CY is taken out from the AND gates 65-1 to 65-12, and the vibrato control of each sounding channel is outputted from the vibrato control information generation circuit 12 in a time-division manner using this AND signal. Latch circuits 64-1 to 64-12 for channels corresponding to information VS, respectively
and each latch circuit 64-1 to 64-1
Alternatively, the vibrato control information VS' of each channel latched at 2 may be selectively outputted by the selector 66 in accordance with the time division timing of each sound generation channel. Further, since the vibrato control information generating circuit 12 can be constructed in the same manner as the vibrato control circuit shown in, for example, the above-mentioned Japanese Patent Application Laid-Open No. 52-37031, a detailed explanation thereof will be omitted.

FIG. 5 is a block diagram showing another embodiment of the invention. This embodiment relates to a single-note electronic musical instrument, and uses information representing the number of sampling clocks required to generate one period of a musical sound waveform as frequency information for defining the reference pitch of musical tones.

In FIG. 5, pressed keys in a keyboard circuit 21 are detected by a pressed key detection circuit 22. As shown in FIG. Then, the pressed key detection circuit 22 outputs a key code KC corresponding to the pressed key. This key code KC is
It is composed of an octave code OC representing the octave range of the pressed key and a note code NC representing the pitch name, of which the note code NC is supplied to the frequency information memory 23 as an address signal.

The frequency information memory 23 stores frequency information P _N corresponding to the reference pitch of each note name (C to B) in a predetermined octave range. in this case,
The frequency information P _N represents the number of sampling clocks required to generate one period of the musical waveform of the reference pitch. Therefore, by providing the frequency information memory 23 with the note code NC corresponding to the note name of the pressed key from the pressed key detection circuit 22,
Frequency information P _N corresponding to this note code NC is read out and output.

This frequency information P _N is supplied to the shift circuit 24, where each bit position is shifted to the lower bit side (or higher bit side) according to the octave code OC, thereby changing the frequency corresponding to the octave range of the pressed key. The information is changed to _PN . This frequency information P is then input to the multiplier 25,
By being multiplied by the vibrato control information VS output from the vibrato control information generation circuit 26,
After being changed in accordance with the vibrato effect, it is latched into the latch circuit 27 by the cycle signal CY generated at the beginning of one cycle of the musical waveform.

Frequency information latched in latch circuit 27
P'' is input to the shift circuit 29 via the gate 28, where it is shifted to the lower bit side.Specifically, the number of sample points in one period of the musical waveform is 64, and the phase of each of these 64 sample points is When using a waveform memory that stores waveform amplitude values, frequency information
Shift 6 bits to the lower bit side to make P'' 1/64.

As a result, the number of sampling clocks for advancing the phase of 64 sample points by one phase has been determined.

The phase step information _PX outputted from the shift circuit 29 in this manner is input to the register 31 via the adder 30, and is stored by the DA conversion clock signal DACL corresponding to the sampling clock. Then, the phase step information _P
By feeding back the phase step information PX, the phase step information _PX is accumulated. In this case, the gate 32 receives a key-on pulse from the key press detection circuit 22 at the start of pressing a new key.
When KONP is output, or when a cycle signal CY indicating the start of one cycle of musical sound waveform is output from the address counter 39, which will be described later, the output signal of the OR gate 34 is inverted by the inverter 33, and the gate is closed. Accordingly, the accumulated value i· _Px (i=1, 2, . . . ) of the phase step information PX is initially set to Px at the start of one period of the musical tone waveform.

Accumulated signal i・Px output from register 31
is input to the comparison circuit 35. This comparison circuit 35
The other comparison input of is given the count output of a counter 36 that counts the DA conversion clock signal DACL generated from the clock generator 37,
A match between this count output value and the accumulated signal i·Px is required. In this case, the counter 36 is reset by the output signal of the OR gate 38 when the key-on pulse KONP generated at the start of pressing a new key or the cycle signal CY indicating the start of one cycle of the musical sound waveform is generated. It's getting old.

Therefore, the counter 36 outputs the DA conversion clock signal from the start of one cycle of the musical waveform to the present.
A count value representing the number of DACL occurrences is output. In addition, in the comparison circuit 35, the number of DACL occurrences of the DA conversion clock signal from the start of one cycle of the musical waveform to the present, and the accumulated signal i.
This means that a match with Px is required.

Therefore, when the count value of the counter 36 and the accumulated signal i·Px match, the comparison circuit 35 outputs a match signal EQ. This coincidence signal EQ is supplied to the count input of the address counter 39, and at the same time is supplied to the gate 28 as an open signal. As a result, the address counter 39 is set to the waveform memory 4.
The address signal for 0 is updated by "1".
On the other hand, since the gate 28 is opened by the coincidence signal EQ, the adder 30 receives phase increment information for further advancing the sample point phase by one phase.
Px is input and added to the current accumulated value signal i·Px fed back from the gate 32. As a result, the register 31 outputs an accumulated value signal i·Px representing the number of DA conversion clocks required to advance to the next sample point phase.

In this way, the current DA conversion clock signal
A match signal EQ is generated from the comparator circuit 35 every time the number of DACLs generated matches the accumulated value signal i·Px representing the number of DA conversion clocks required to advance to the next sample point phase.

As a result, the phase signal x output from the address counter 39 is updated by "1" each time the coincidence signal EQ is generated. In this case, the update rate of the address signal corresponds to the phase step information Px (ie, the frequency information P'').

Note that the address counter 39 overflows and each time the value of the phase signal (address signal) Each time the period sample point phase specification begins,
At this starting point, the cycle signal CY is made similar to that of the frequency counter 7 in FIG.

Through the above-described operation, frequency information is extracted from the waveform memory 40 that stores the amplitude values of each sample point in one period of the musical waveform for 64 sample point phases.
The waveform amplitude value of each sample point phase is read out at a speed corresponding to P'' (phase step information Px) (that is, corresponding to the pitch of the pressed key and the value of the vibrato control information VS), and The waveform memory 40 stores a plurality of musical sound waveforms corresponding to each of the tones selectable in the timbre selection circuit 41, and these tones are Among them, the amplitude value of each sample point of the musical waveform corresponding to the selected timbre is read out according to the phase signal x from the address counter 39.

As a result, a musical tone signal corresponding to the tone selected by the tone color selection circuit 41 is output.

The musical tone signal output in this way is input to the envelope control circuit 42, and the key-on signal is input to the envelope control circuit 42.
When KON occurs (i.e. when the key starts being pressed)
The amplitude envelope corresponding to the selected timbre is controlled during the period from to the end. Specifically, the amplitude envelope is controlled by an envelope signal generated from the time of generation of the key-on signal KON with a waveform shape corresponding to the selected timbre based on the timbre selection information TC indicating the selected timbre. The musical tone signal controlled by this amplitude envelope is
DA conversion clock signal in DA converter 43
Synchronized with DACL, converted to analog musical tone signal,
The sound system 44 produces musical tones.

Incidentally, in this embodiment as well, the frequency information P corresponding to the pitch of the pressed key is modulated and controlled by the vibrato control information VS for the vibrato effect, so the vibrato control information VS is similar to the embodiment shown in FIG. A musical tone whose pitch (frequency) changes in response to the time change of is generated, but in this case, the frequency information modulated by the vibrato control information VS
P' is latched in the latch circuit 27 by the cycle signal CY generated from the address counter 39 at the start of one cycle of the musical tone waveform. Therefore, the frequency information P'' output from the latch circuit 27 does not change during one cycle of the musical sound waveform.In other words, the amplitude value of each sample point generated from the waveform memory 40 during one cycle of the musical sound waveform does not change. The phase interval will no longer change suddenly, and noise generation will be prevented.

In the embodiment shown in FIG. 1, the vibrato control information VS is latched every time the cycle signal CY occurs, and the frequency information F is modulated and controlled using this latched information VS', but the embodiment shown in FIG. Similarly, after modulating the frequency information F using the vibrato control information VS, the information F' after this control is converted into a cycle signal.
It is also possible to latch it at CY and supply it to the frequency counter 7.

Similarly, in the embodiment shown in FIG. 5, information P' after frequency control information P is controlled by vibrato control information VS is latched by cycle signal CY and supplied to gate 28. , the vibrato control information VS may be latched every time the cycle signal CY occurs, and the latched information VS' may be supplied to the multiplier 25. In the embodiment shown in FIG. 5, the output P of the shift circuit 24 is directly supplied to the shift circuit 29, and a multiplier corresponding to the multiplier 25 is provided between the register 31 and the comparator 35. In this multiplier, the above-mentioned vibrato control information VS is latched by the cycle signal CY, and the information VS' is combined with the output i of the register 31.
Px and the multiplication result may be supplied to the comparison circuit 35.

Further, in each of the embodiments, the phase signal x is formed by accumulating the frequency information F or the phase step information Px, but the phase signal x may also be formed by subtraction. . Further, the method of forming the phase signal x is not limited to the method of the above-mentioned embodiments, but any arbitrary method can be used. Those using value data, P number, R number as shown in Japanese Patent Application No. 100840/1984,
It is possible to use a method that uses a D number or the like.
In this case, to add a vibrato effect,
The frequency division value data, P number, R number, or D number may be modulated as appropriate using the vibrato control information VS (VS').

Further, in the above embodiment, the musical sound waveform stored in the waveform memories 8 and 40 is one cycle, but the entire waveform from the start to the end of the musical sound or a multi-frequency waveform of a part thereof may be stored. Good too.

Further, in the above embodiment, the musical tone signal is generated using a waveform memory that stores the musical sound waveform, but the musical tone signal is not limited to this, and the musical tone signal may be generated by frequency modulation, harmonic synthesis method, etc. Good too. In short, any device that generates a musical tone signal (including a sound source signal) in accordance with the phase signal X may be used.

Furthermore, in the above embodiment, a case where a musical tone signal with a vibrato effect is generated as a pitch variation effect has been described as a representative example, but a glide effect,
Even when applying a pitch modulation effect such as an attack pitch effect, it can be implemented in exactly the same way.
In this case, as the vibrato control information generating circuits 12 and 26 in FIGS. 1 and 5, for example,
A control signal generation circuit such as that shown in Japanese Patent No.-9434 may be used.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the pitch information modulated by the pitch modulation information is prohibited from changing until the generation of one period of the musical sound waveform is completed, and each sample of one period of the musical sound waveform is Since the phase interval between the points is made constant, it is possible to generate a musical tone signal with a pitch modulation effect such as a vibrato effect without producing noise.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing a specific example of the time division latch in the embodiment of FIG. 1, and FIG. FIG. 4 is a time chart showing the timing with the cycle signal; FIG. 4 is a diagram showing another specific example of the time division latch in the embodiment of FIG. 1; FIG.
The figure is a block diagram showing another embodiment of the invention. 1, 21... Keyboard circuit, 4... Frequency information generation circuit, 5... Multiplier, 6... Time division latch, 7...
...Frequency counter, 8...Music waveform memory, 1
2, 26... Vibrato control information generation circuit, 23
...Frequency information memory, 27...Latch circuit, 3
9... Address counter, 40... Waveform memory.

Claims (1)

[Scope of Claims] 1. pitch specifying means for specifying the pitch of a musical tone to be generated; pitch information generating means for generating pitch information corresponding to the pitch specified by the pitch specifying means; pitch modulation information generation means for generating pitch modulation information; modulation means for modulating the pitch information with the pitch modulation information; phase information generation means for generating phase information that sequentially specifies sample point phases; musical tone generation means for generating a musical tone signal according to the phase information; An electronic musical instrument comprising: control means for prohibiting changes in modulated pitch information and maintaining the same content, and performing control to enable changes in the modulated pitch information in synchronization with the end of the one cycle. . 2. The phase information generating means is configured to repeatedly output a one-period end signal in synchronization with the phase information ending designation of the final sample point phase for one period of the musical tone signal, and the control means: 2. The electronic musical instrument according to claim 1, wherein said control is performed in accordance with said one cycle end signal. 3. The control means includes a latch means that latches the pitch modulation information using the one-period end signal, and the modulation means modulates the pitch information using the pitch modulation information latched by the latch means. An electronic musical instrument according to claim 2, wherein the electronic musical instrument comprises: 4. The control means includes a latch means for latching the modulated pitch information by the one-period end signal, and the phase information generation means generates the phase information based on the pitch information latched by the latch means. The electronic musical instrument according to claim 2, which generates.