JPS581791B2 - Denshigatsukino Vibra-Toseigiyosouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibrato control device that can realize delay vibrato in a tone generator used in an electronic musical instrument.

As shown in FIG. 1, the digital tone generator includes a shift register 1, a NOR circuit 2, an exclusive OR circuit 3
A maximum period counter consisting of an OR circuit 4 is driven by a mask clock pulse φ, a digital numerical signal corresponding to the note selected by the keyboard switch circuit 5 is read from the read-only memory 6, and this digital numerical signal and the maximum period are A comparator 7 compares the contents of the counter (parallel output of the shift register 1), and when the two match, the shift register 1 is reset.

The match detection output of the comparator 7 is delayed by one pulse φ clock by a delay flip-flop 8, and is applied to the shift register 1 as a reset signal, as well as the output pulse signal of this tone generator, that is, the tone selected by the keyboard switch circuit 5. It is output from the output terminal 9 as a frequency signal.

Note that if the shift register 1 is reset the moment a match is detected by the comparator 7, a slight delay may cause malfunction, so a 1-bit delay flip-flop 8 is provided to reset the shift register 1 with a 1-bit time delay from the time a match is detected. I try to do it.

Therefore, the delay flip-flop 8 serves as a puffer circuit to prevent malfunction.

Next, a brief explanation will be given of how the mask clock pulse φ is divided into a desired frequency in the tone generator of FIG.

When one tone is selected by the keyboard switch circuit 5, a digital numerical signal corresponding to that tone (note name) is read out from the read-only memory 6.

On the other hand, since the contents of the parallel outputs of each stage of the shift register 1 change every moment at the timing of the master clock pulse φ, the contents of the register 1 and the read-only memory 6 change during one cycle of the contents change of the register 1. There are cases where the read contents always match once.

For example, if comparator 7 detects a match when n clock pulses φ are applied to shift register 1 starting from when the contents of shift register 1 are all 0, n+1 clock pulses φ will be generated. shift register 1 every
A reset signal is applied to the frequency-divided output corresponding to the frequency of the sound selected by the mask clock inch circuit 5.

Assuming that the shift register 1 has 9 bits and the 5th and 9th bits are connected to the exclusive OR circuit 3 as shown in the figure, the contents of the shift register 1 are changed as shown in Table 1 every time a pulse φ is applied. changes.

Further, if the content of the digital numerical value read out from the read-only memory 6 in response to the selection of the keyboard switch circuit 5 is, for example, 100001000, it matches the content of the sixth item in Table 1.

Therefore, when six pulses φ are added, the comparator 7 detects a match, the match detection output ID becomes "1", and the shift register 1 is reset one pulse later.

Therefore, in this case, a reset signal is repeatedly generated every time seven pulses φ are applied and taken out from the mask chronograph 9.

In this way, a frequency signal with a desired pitch is obtained.

In the tone generator having the above configuration, vibrato is conventionally applied to the generated sound (frequency-divided output) by modulating the frequency of the master clock pulse φ by the vibrato frequency.

However, the oscillation frequency of the mask clock pulse φ is 2MH
z, and modulating this has the disadvantage of lacking frequency stability and decreasing accuracy.

Furthermore, it is quite troublesome to apply delay vibrato in a tone generator configured as described above.

SUMMARY OF THE INVENTION An object of the present invention is to configure a tone generator so that vibrato can be applied without modulating the frequency of a master clock pulse, and to also realize delay vibrato with a simple configuration. shall be.

According to this invention, the coincidence detection output ID of the comparator 7, that is, the output of the delay flip block 8, is delayed by an appropriate time and used as a reset signal for the shift register 1, thereby shifting the reset timing according to the delay time. , thereby realizing modulation of the frequency-divided output.

Then, by periodically varying the delay time according to the vibrato frequency, the reset timing is periodically shifted to obtain a frequency-divided output with vibrato applied.

In addition, the delay vibrato is configured so that the change width of the delay time can be switched periodically, and the change width is gradually increased as time elapses after the key is pressed, thereby gradually deepening the vibrato. Realize.

That is, according to the present invention, there is provided a counting means whose contents are sequentially changed from an initial value in accordance with a clock pulse, and a value in which the contents of this counting means are different from the initial value by a value corresponding to a predetermined pitch. an electronic discharge means for detecting a pulse, and uses the detection output of the detection means as an initial value setting signal of the counting means to obtain an output pulse of a desired period according to the initial value setting timing of the counting means. In a tone generator of a musical instrument, a first circuit sequentially delays the detection output of the detection means in a plurality of stages and extracts a plurality of delayed signals having different delay times, and some of the delayed signals extracted by the first circuit. is selected periodically in order at a speed related to the vibrato frequency, and the selected delayed signal is supplied to the counting means as an initial value setting signal, and is selected by this second circuit. a third circuit that specifies the plurality of delayed signals and changes the combination of the delayed signals according to the passage of time after the key is pressed;
A vibrato whose depth changes depending on the time elapsed after the key is pressed is applied.

The invention will now be described in detail with reference to the embodiments of the accompanying drawings.

In the tone generator 10 of FIG. 2, the same devices as those in FIG. 1 are designated by the same reference numerals for convenience.

A delay vibrato addition circuit 11 is inserted between the delay flip-flop 8 and the manual reset side of the shift register 1, and it periodically shifts the reset timing of the shift register 1 according to the vibrato frequency, and also adjusts the timing of key presses. The amount of shift in the reset timing is increased stepwise as time passes.

The shift register 12 sequentially shifts the output of the delay flip-flop 8 at the speed of the master clock pulse φ, and sequentially delays the match detection output ID of the comparator 7 (i.e., the output of the delay flip-flop 8) in multiple stages, each with a delay time. Delayed outputs with different values are obtained in parallel from each stage.

A delayed match detection signal ID'=(
The delay time until the signal ="1" appears is one bit time of the master clock pulse φ.

The delay time from when this delayed match detection output ■D' is read into the shift register 12 until it is output from the output line 14 of the second stage is 3 bit times (in this example, the delay time between the first stage and the (The output of the first row is not used.)

Furthermore, output lines 15, 16, 17 .
The delayed output of No. 18 has a delay of 4 bit time to 7 bit time, and the signal of the output line 19 of the 8th stage is delayed by 9 bit time than the coincidence detection output ID.

When n master clock pulses φ are added to shift register 1 counting from when the contents of shift register 1 (counter) are all 0 (when it is reset), the contents of shift register 1 and read-only Assuming that the comparator 7 detects that the digital value read from the memory 6 matches, when n+1 pulses φ are added to the shift register 1, the output of the line 13 becomes "1", and the output of the line 13 becomes "1". The signals on line 14 become "1" when the number is n+4, line 15 when the number is n+4, line 16 when the number is n+5, line 17 when the number is n+6, line 18 when the number is n+7, and line 19 when the number is n+9.

Lines 13, 14, 15, 16, 17, 18 or 19
Considering the case where the signal "1" becomes the reset signal for the shift register 1, the frequency division ratio in the tone generator 10 is as shown in column A of Table 2.

As is clear from column A of Table 2, if the delay time of the signal used as the reset signal for the shift register 1 differs, the frequency division ratio also changes accordingly.

For example, if the delayed output of line 16 is used as a reset signal for shift register 1, the frequency-divided output pulse φ
Assuming that the frequency is m=n+5, the divided outputs when the signals on each line 13 to 19 are used as reset signals are as shown in column B of Table 2.

The divided output according to line 13.14 or 15 is higher than that of reference line 16 and line 17.18 or 19
The divided output by is lower than that of the reference line 16.

Of course, the content 5 of the digital numerical value read out from the read-only memory 6 is set to a value that corresponds to the regular pitch of the selected note.

The vibrato depth setting switches 20, 21, 22, and 23 are switches for changing the depth of the delay vibrato, and the details will be described later. The explanation will be based on the assumption that it has been set.

When the switches 20 to 23 are connected to the positions shown in FIG.
The delayed outputs appearing at 16, 17, and 18 are output from the AND circuit 24.
- 30, and is used as a reset signal for the shift register 1 when the conditions of the AND circuits 24-30 are satisfied.

The shift register 31 sequentially shifts the signal "1" applied from the NOR circuit 33 by the vibrato clock pulse VP supplied from the vibrato oscillator 32, and outputs the output lines 34, 35, 36 of each stage and the output line 37 of the NOR circuit 33. The signal "1" is generated sequentially at the speed of the vibrato clock pulse VP.

The signals on lines 37 and 35 are connected to AND circuits 24 and 2.
6 and selects the reference delay output line 16.

The signal on line 34 is applied to AND circuits 25 and 28;
The delayed output of switch 22 or 23 having a delay time slower than that of reference line 16 is selected.

The signal on line 36 is applied to AND circuits 27 and 29;
The delayed output of the switch 20 or 21 having a faster delay time than the reference line 16 is selected.

Therefore, when the signal "1" occurs repeatedly on lines 37, 34, 35, and 36 at the speed of the vibrato clock pulse VP, line 16, line 17, line 18, line 16
, the delayed output of line 14 or 15 is periodically selected by AND circuits 24 to 29, and becomes a reset signal for shift register 1 via OR circuit 38.

When the delayed output line used as a reset signal for shift register 1 changes periodically by the signals on lines 34 to 37, the frequency division ratio changes periodically as shown in Table 2 above, and the divided output becomes normal. Piru.

The vibrato frequency is set by the frequency of the vibrato clock pulse VP.

In the example shown in FIG. 2, the pitch changes four times in one vibrato period, so when the vibrato frequency is 7 Hz, the frequency of the vibrato clock pulse VP is preferably set to 28 Hz.

By the way, in the AND circuits 24 to 29, the shift register 3
The signals on the delayed output lines 13-19 are selected by the signals on the lines 34-37 only when the condition of the third input from 9 is satisfied.

The shift register 39 is a circuit for controlling temporal changes in vibrato depth in delay vibrato,
The change time of the vibrato depth is set by the depth change time setting clock pulse DP supplied from the oscillator 40.

When a key is pressed on the keyboard (not shown), shift register 3
9 is reset, the delay oscillator 40 starts operating (or is reset), and delay vibrato control starts.

First, this point will be explained. In the key press detection switch circuit 5', individual switches are provided corresponding to each key so as to be linked with the operation of each switch of the keyboard switch circuit 5, but the fixed contact and movable contact side of each switch are They are all connected in common, and when a key is pressed, a signal “
1'' is applied to the differential circuit 41.

Therefore, as shown in FIG. 3a, one pulse is generated from the differentiating circuit 41 at the beginning of the key depression.

The shift register 39 is controlled by the output pulse of the differentiating circuit 41.
is reset, and all outputs from each stage become "0" (Fig. 3c, d).

At this time, the output of the NOR circuit 42 becomes "1" (Fig. 3 e
), the AND circuit 30 becomes operational.

Since the other AND circuits 24 to 29 are all inoperable, only the signal on the reference delay output line 16 connected to the AND circuit 30 is used as a reset signal for the shift register 1.

Therefore, the output terminal of the tone generator 10 is maintained, and as shown in FIG. 3f, no vibrato is applied and the normal pitch is maintained for a while after the key is pressed.

The state in which no vibrato is applied is connected until the signal "1" is read into the first stage of the shift register 39.

The delay oscillator 40 can be constructed of transistors Tr1, Tr2, Tr3, a capacitor 01, etc., as shown in FIG. 4, for example.

As shown in FIG. 3a, when one pulse is applied from the differentiating circuit 41, it is reset and the time T corresponding to the oscillation period is
1, a pulse is output from the collector side of the transistor Tr3, and thereafter, as shown in FIG. 3b, a vibrato depth change time setting pulse DP is oscillated at a constant period T1.

Of course, the speed of this pulse DP is sufficiently slower than the vibrato clock pulse VP.

The first pulse DP generated from the oscillator 4o after a time T1 from the start of key depression is applied to the shift clock input of the shift register 39 via the AND circuit 43.

This first pulse DP causes the signal "1" to be read into the first stage of the shift register, causing the signal on the output line 44 to become "1".
'' (FIG. 3C), the AND circuits 24 and 26 are enabled via the AND circuits 25 and 27 and the OR circuits 45 and 46.

On the other hand, since the output of the NOR circuit 42 becomes "0", the AND circuit 30 becomes inoperable.

The delay output lines to be selected in the AND circuits 24 to 27 that have become operational are only the reference line 16 and the lines 15.17 (or 14.18) connected to the switches 21 and 22.

Therefore, when a signal "1" is produced in sequence and repeatedly on output lines 37, 34, 35, 36 of shift register 31 according to vibrato clock pulse VP, delayed output lines 16, 17, 16, 15 are repeatedly and sequentially shifted This becomes a reset signal for register 1.

In this case, as is clear from Table 2 above, the pitch of the frequency-divided output changes periodically up and down in the following order, and vibrato is applied.

In this way, a vibrato with a depth of 1 is applied as shown in FIG. 3f.

Note that a depth of 0 indicates a state in which the vibrato has never been performed, and the vibrato depth becomes deeper as the number increases, such as depth 1, 2, and so on.

When time T1 further elapses, the second pulse DP is applied to the shift register 39, the signal "1" is transferred to the second stage, and the line 47 becomes the signal "1" (FIG. 3d).

As a result, the AND circuits 24, 26, 28, and 29 become operable, and the other AND circuits 25, 27, and 30 become inoperable.

The signals of delay lines 14 and 18 (or 13 and 19) connected to line 16 and switches 20 and 23 are therefore used as reset signals for shift register 1.

That is, output lines 37, 34, 35 and 36 of shift register 31 are activated according to vibrato clock pulse VP.
When the signal "1" occurs sequentially and repeatedly, the delayed outputs of the delayed output lines 16, 18, 16, 14 sequentially and repeatedly become the reset signal of the shift register 1.

Therefore, the pitch of the frequency-divided output of the tone generator 10 changes periodically in the upward and downward directions, and a vibrato of depth 2 is applied as shown in FIG. 3f.

For example, when the deepest vibrato is set to a depth of 2, the output of the second stage of the shift register 39 is inverted by the inverter 48 and added to the AND circuit 43, and when the depth reaches 2, the AND circuit 43 is disabled and the delay The pulse DP from the oscillator 40 is blocked.

After that, the shift register 39 is not shifted and the final stage (2
The maximum depth (depth 2) when the signal “1” is held in the first row)
maintain.

If you wish to cancel the vibrato midway through, turn on the vibrato switch 49 and reset the vibrato shift register 31.

As a result, only the AND circuit becomes operable, and the frequency-divided output of the normal pitch is maintained.

As described above, it is possible to realize a delay vibrato in which the depth of the vibrato increases in stages as time passes after a key is pressed.

Of course, a shift register can be implemented.

Of course, by increasing the number of stages of shift registers 39, 12, etc., smoother delay vibrato can be applied.

Next, a switch 20 to change the degree of vibrato depth.
23 will be explained.

Switches 20 to 23 are designed to be interlocked, and the second
The first switching position shown in the figure or the switch 20
The switch 21 is connected to the line 13, the switch 21 is connected to the line 14, the switch 22 is connected to the line 18, and the switch 23 is connected to the line 19.

Referring to Table 2, when set to the second switching position,
At vibrato depth 1, the pitch of the frequency-divided output changes repeatedly in the following order, and the same depth of vibrato as at depth 2 at the first switching position is applied.

Further, at depth 2 at the second switching position, the pitch changes repeatedly in this order, and a deeper vibrato is applied.

Therefore, by switching the switches 20 to 23, the overall vibrato depth in the delay vibrato can be adjusted.

FIG. 5 shows a modification of the delay vibrato addition circuit 11 of FIG. 2, in which only the periphery of the shift register 39 is shown, and other parts that are the same as those in FIG. 2 are omitted.

In the example shown in FIG. 5, the time to maintain the depth 0, that is, the normal pitch, is longer.

When applying one pulse (FIG. 6a) output from the differentiation circuit 41 at the beginning of a key press to the delay oscillator 40, a one-shot circuit 50 is interposed to delay the start of operation of the oscillator 40. .

The time T0 set by the one-shot circuit 50 (Fig. 6b)
), the delay oscillator 40 starts operating (Fig. 6C).
), the time at depth O where no vibrato is applied is T0 + T1
(Fig. 6 d).

A desirable delay vibrato effect can be obtained by making the time during which no vibrato is applied at the beginning of sound production as long as possible, and by applying vibrato that becomes deeper in stages as concentrated as possible after the start of sound production.

Of course, the operating time T0 of the one-shot circuit 50 can be set arbitrarily.

FIG. 7 shows another modified example of the delay vibrato adding circuit 11, in which only the periphery of the shift register 39 is shown, and the other parts are omitted because they are the same as in FIG. 2.

In the example of FIG. 7, the duration of depth O is one-shot circuit 5.
The configuration is such that it depends only on the operating time To of 0.

One pulse (
In FIG. 8a), the one-shot circuit 50 is driven, and after an operating time T0 (FIG. 8b), the delay oscillator 40 starts operating (FIG. 8d).

The output of the one-shot circuit 50 is also applied to a differential rectifier circuit 51, which generates a negative pulse when the operating time T0 ends.

The negative pulse is inverted by an inverter 52 (FIG. 8C),
First stage flip-flop 39d of shift register 39
Set.

Therefore, at the end of the operating time T0 of the one-shot circuit 50, the output line 44 of the first stage of the shift register 39 becomes a signal "1", and a vibrato of depth 1 is applied as shown in FIG. 8e.

After the operating time T0, when the time T1 elapses, the oscillator 40 outputs the pulse DP, and the first stage flip-flop 3
The signal "1" at 9a is shifted to the second stage flip-flop 39b, and the vibrato depth shifts to depth 2.

In the circuit shown in FIG. 7, the output of the NOR circuit 42 is not input to the shift register 39.

As described above, the duration of depth 0 without vibrato depends only on the operating time T0 of the one-shot circuit 50, and by appropriately setting the operating time T0, the duration of depth 0 can be freely set.

If you want to apply delay vibrato to each note of the 12-tone scale separately, use a tone generator 10 with a delay vibrato addition circuit as shown in Figure 2, Figure 5, or Figure 7 for each note. It is good to have one for each name.

As explained above, according to the present invention, delay vibrato can be realized with a simple configuration.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an example of a conventional tone generator, FIG. 2 is a block diagram showing an embodiment of the present invention,
3 is a timing chart explaining the delay vibrato control operation by the device shown in FIG. 2, FIG. 4 is a circuit diagram showing an example of a delay oscillator, and FIG. 5 is a block diagram showing a modification of FIG. 2. 6 is a timing chart explaining the delay vibrado control operation by the device shown in FIG. 5, FIG. 7 is a block diagram showing another modification of FIG. 2, and FIG. 8 is a timing chart explaining the delay vibrado control operation by the device shown in FIG. 5 is a timing chart illustrating a control operation. 10... Tone generator, 11... Delay vibrato addition circuit, 12... Shift register for reset timing delay, 20-23... Vibrato depth setting switch, 31... Shift register for vibrato, 32...
Vibrato oscillator, 39... Delay shift 1-regisc, 40... Delay oscillator, 41... Differential circuit, 5
0... One-shot circuit, 51... Differential rectifier circuit.

Claims (1)

[Claims] 1. A counting means that sequentially changes its contents from an initial value in accordance with a clock pulse, and a detecting means for detecting that the contents of this counting means have become a value that is different from the initial value by a value corresponding to a predetermined pitch. In the tone generator of an electronic musical instrument, the detection output of the detection means is used as an initial value setting signal of the counting means to obtain an output pulse of a desired period according to the initial value setting timing of the counting means. The detection output of the detection means is sequentially delayed in multiple stages,
a first circuit that extracts a plurality of delayed signals with different delay times; and a first circuit that sequentially and periodically selects some of the delayed signals extracted by the first circuit at a speed related to the vibrato frequency; a second circuit that supplies the signal to the counting means as an initial value setting signal; the second circuit specifies the several delayed signals to be selected; and a key is pressed to select a combination of the delayed signals. A vibrato control device for an electronic musical instrument, comprising a third circuit that changes in accordance with the elapse of time after a key is pressed, and applies vibrato whose depth changes in accordance with the elapse of time after a key is pressed.