JPH0241677Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an octave control circuit for an electronic musical instrument that shifts and controls the octave of a note pressed by a key touch.

Conventionally, in order to reduce the cost of single-stage keyboards for electronic musical instruments, the number of keys has been reduced, and the sound production area has tended to be narrow. Therefore, even on a two-octave keyboard as shown in FIG. 1, the sound generation range was expanded to four octaves by controlling the octave down and up. In order to shift the octave down or up, an octave shift switch was conventionally provided on the panel. However, this method using a changeover switch has the drawback that it makes the performance inconvenient because the user has to take one hand off during the performance.

This idea was made in view of the above circumstances.
An object of the present invention is to provide an octave control circuit for an electronic musical instrument that can generate a wide sound generation range with a small number of keys by controlling the shift of the octave of a sound pressed by a key touch.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 2 shows an embodiment of the present invention, in which the open/close states of the key switches and touch switches of all the keys of the keyboard circuit 1 are detected every round of the ring counter of the keyboard scanning circuit 2, which is driven in steps by the clock pulse P. , a keying TDM (time division multiplexed signal) and a touch TDM, and this keying TDM is applied to the demultiplex circuit 3. This demultiplex circuit 3 has one keyboard scanning circuit 2.
A synchronizing signal SY is added each time scanning is completed. The demultiplex circuit 3 converts the keying TDM into parallel signals corresponding to each key, and this signal is applied to the gate circuit 4. This gate circuit 4
is a musical tone signal generator (tone generator TG)
The musical tone signal from 5 is added, and the musical tone signal is extracted only from the gate opened by the keying signal. Therefore, gates that are not pressed and to which no keying signal is applied are closed and no musical tone signal is extracted. The output of each gate of the gate circuit 4 is
The signals are applied to one input terminal of a plurality of AND circuits 7 provided in the octave shift control circuit 6, respectively, and are multiplied by two times by the corresponding multipliers 8, and then added to the octave shift control circuit 6. are applied to one input terminal of another plurality of AND circuits 9 corresponding to each other. On the other hand, when the keyboard scanning circuit 2 scans the keyboard of the keyboard circuit 1 from the treble side to the bass side, the touch TDM is extracted from the pressed key and added to the demultiplex circuit 10. A synchronizing signal SY output from the keyboard scanning circuit 12 every time one scan is completed is applied to the demultiplexing circuit 10.
In the demultiplex circuit 10, the touch TDM is converted into parallel signals corresponding to each key, and these signals are respectively applied to the other input terminal of the AND circuit 7 via the corresponding inverters 11, and is applied to the other input of circuit 9.
The output of this AND circuit 9 and the output of the AND circuit 7 are respectively applied to the input terminals of the corresponding OR circuit 12, and the output of this OR circuit 12 is applied to a mixing tone circuit 13 that creates a sound using a filter or the like. The output of the timbre circuit 13 is applied to a sound system 14 comprising an amplifier, a speaker, etc., and is emitted as sound.

Therefore, when the power switch is turned on and the keyboard scanning circuit 12 starts scanning, the keyboard scanning circuit 12
Keying TDM and touch TDM are output from. If you press the key with normal force, a pulse output will appear only in the keying TDM, and no pulse output will appear in the touch TDM. Therefore, the pulse from the keying TDM opens a predetermined gate of the gate circuit 4 via the demultiplex circuit 3, and a musical tone signal corresponding to the gate is added to the AND circuit 7 corresponding to the pressed key. At the same time, since there is no pulse in the touch TDM, the output extracted from the inverter 11 to which the parallel signal of the touch TDM is applied via the demultiplex circuit 10 is added. Therefore, an output is extracted to the AND circuit 7 corresponding to the pressed key, and this output is applied to the sound system 14 via the OR circuit 12 and mixed timbre circuit 13 and converted into audio.

On the other hand, if the key is pressed with more force than normal, a pulse appears on the keying TDM and also on the touch TDM. Therefore, no output is extracted to the inverter 11, and no output appears to the AND circuit 7. However, the gate circuit 4 opened by the keying TDM pulse is connected to the AND circuit 9 corresponding to the pressed key.
The musical tone signal passed through the gate is converted to 2 by the multiplier 8.
In addition to being multiplied and added, Tatsuchi TDM
pulses are applied via the demultiplex circuit 10. Therefore, a twice-multiplied musical tone signal is extracted from the AND circuit 9 corresponding to the pressed key.
This twice the musical tone signal is output from the sound system 14 via the OR circuit 12 and the mixed tone circuit 13 as an audio signal whose octave has been shifted twice.

As described above, the output of the gate circuit 4 is transferred to the multiplier 8.
The touch signal can be used to select between a signal multiplied by 1 octave (one octave up) and the signal as is.

Note that a frequency divider may be used in place of the multiplier shown in FIG. 2 to obtain a signal whose frequency is divided by 1/2 (1 octave down).

Further, the keying signal and the touch signal do not need to be TDM signals, and the demultiplex circuit may be omitted and the gate circuit may be directly controlled.

Keying TDM and touch depending on the strength of the key press
As shown in Fig. 3, the method of obtaining TDM is to provide a touch sensor 15 in the keyboard circuit, compare the output from this touch sensor 15 with a reference voltage Vo in a comparator 16, and use the output of this comparator 16 to set the base of the transistor. It may also be controlled. In this case, the reference voltage Vo can be appropriately set in accordance with the octave-shifted pressing force. As shown in Fig. 4, if we look at one cycle of the keyboard scanning circuit 2, if we now strongly press the _C3 key and press the _C2 , _E2 , and _G2 keys normally. Then, Tatsuchi TDM appears at C ₃ , raising the pitch by one octave, and C ₃ is pronounced as C ₄ . Other sounds are pronounced as C ₂ , E ₂ , and G ₂ .

Furthermore, in order to detect the touch signal, it is not necessary to use a sensor to generate an electrical output, but as shown in FIG. 5, a mechanical switch may be used. That is, two movable contact pieces 18, 19 are provided at the lower part of the key 17, separated by a predetermined distance, and leaf contacts 20, 2 are provided corresponding to the operable positions of the movable contact pieces 18, 19, respectively.
1 will be provided. In this case, the contact spacing B of the leaf contacts 21 is set wider than the contact spacing A of the leaf contacts 20, and when the key is pressed with normal force (depth), only the leaf contacts 20 are closed; deeply)
When the key is pressed, the leaf contact 21 is also closed.

FIG. 6 shows another embodiment of the present invention, in which a key chord detected by a single-note electronic musical instrument is octaved up. That is, the keyboard scanning circuit 12 is driven by the clock pulse P to open and close the key switches and touch switches of all the keys in the keyboard circuit 1.
The synchronization signal SY, keying TDM, and touch TDM as shown in FIG. 4 are detected every round of the ring counter. The keying
TDM is applied to one input of the AND circuit 23 of the single note priority circuit 22, and the synchronizing signal SY is applied to the set S of the flip-flop 24 of the single note priority circuit 22. The output Q of the flip-flop 24 is applied to the other input terminal of the AND circuit 23. This single note priority circuit 22 gives priority to the note corresponding to the first signal of the scanning output, and is normally a single note priority circuit on the treble key side, so only the pulse corresponding to C ₃ is added to the first latch circuit 25. It will be done. The flip-flop 24 is an AND circuit 23
The output of is added to reset R to reset it. The note (scale) counter and octave counter of the counter 26 are driven step by step by the clock pulse P in synchronization with the ring counter of the keyboard scanning circuit 2. Therefore, there is a one-to-one correspondence between the count value of the counter 26 and the key detected by the ring counter. Now, keyboard scanning circuit 2
Assuming that the output terminal corresponding to the key C ₃ of the ring counter is "1", since the key C ₃ is pressed as described above, a pulse "1" is output from the single note priority circuit 22, and the first is supplied to the latch circuit 25 as a load pulse. As a result, the note count value at that time is a note code of C ₃ ,
Also, the octave count value is latched as the _C3 octave code. At this time,
If the key _C3 is pressed down deeply, the touch TDM also becomes "1", so the first latch circuit 25 to which this touch TDM is applied is latched as touch data. The note counter is a quaternary system, and the octave counter is a ternary system. The _C3 data latched in the first latch circuit 25 as described above is transferred from the first latch circuit 25 to the second latch circuit 2 at the rising edge of the next arriving synchronizing signal SY pulse.
Transferred to 7. Further, the first latch circuit 25 is reset at the falling edge of the synchronizing signal SY, and prepares for the next key detection by the ring counter. As mentioned above, key _C3 is pressed deeply and the touch data is "1", so octave shift control circuit 2
The 8th adder circuit 29 generates a code indicating the fourth octave. Therefore, key code memory 3
The data of _C4 is supplied to the input of 0. In the key code memory 30, the data of C ₄ (note code "C" + octave code "4") is sent to the latch circuit 3.
It is latched at 1. This latch circuit 31 is loaded by a load signal from a key-on (hereinafter referred to as KON) detection circuit 32.

The key-on detection circuit 32 includes a comparator 33 that compares the input data and output data of the latch circuit 31 and generates an "A≠B" signal (A is the input data, B is the output data) if they do not match. "A≠B"
The signal is supplied to an AND circuit 35 together with the KON signal from the OR circuit 34, and its output signal is supplied to the latch circuit 31 as a load signal. The fact that the input data and output data of the latch circuit 31 do not match means that a key different from the keys that have been pressed so far has been pressed. In addition, OR circuit 3
4 detects KON by ORing all 7 bits that make up the key code. Also,
In the KON detection circuit 32, a comparator 33
The one-shot multivibrator 36 is driven by the "A≠B" signal, and its output is inverted by an inverter 37 and supplied to the other input terminal of an AND circuit 38 whose one input terminal is supplied with the KON signal,
KON signals are separated.

The key code data from the key code memory 30 is applied to a variable frequency dividing circuit (variable digital tone generator DTG) 40 via a frequency dividing ratio ROM 39. This variable frequency divider circuit 40 divides the master clock MP based on the key code data.
In this example, the frequency corresponding to C ₄ (261,
6Hz). As described in Japanese Patent Publication No. 53-3257, for example, the configuration of the variable frequency dividing circuit 40 is as follows: First, the highest octave frequency signal of a desired note is obtained by the note frequency dividing circuit, and then the frequency signal of the highest octave of the desired note is obtained. The structure may be such that a desired octave can be obtained using a circuit. The variable frequency dividing circuit 4
The output signal of 0 is emitted as an audio signal from the sound system 14 via the opening/closing circuit (gate circuit) 41 and the mixed tone circuit 13.

In the example shown in FIG. 6, since the key is a single note, one touch sensor may be provided for each key. Also, the output of the variable frequency divider circuit can be multiplied (or divided by 1/2) without octave shifting by calculation.
It may be configured to do so.

In the above embodiment, a single-tone electronic musical instrument has been described, but the present invention can be similarly implemented in a multi-tone electronic musical instrument.

Further, the up-down is not limited to one octave, but may be set to normal, ±1 octave, ±2 octave, etc., depending on the soft, medium, or strong touch.

In the above embodiment, the case where only the sound of the pressed key is shifted by an octave has been described, but this is not limited to this. For example, if a key is strongly pressed once, the entire key is shifted by an octave and the state is maintained. ,
It may also be possible to return to the original octave by strongly pressing any key again. Furthermore, the present invention may be used in a synthesizer whose sound source is a voltage-controlled variable oscillator.

As described above, the present invention provides an octave control circuit for an electronic musical instrument that can generate a wide range of sound with a small number of keys by controlling the shift of the octave of a note pressed by a key touch. be able to.

[Brief explanation of the drawing]

FIG. 2 is a configuration explanatory diagram showing an embodiment of the present invention;
FIG. 1 is a perspective view showing an example of a two-octave keyboard;
Figure 3 shows the keying TDM and touch related to this invention.
Configuration explanatory diagram showing an example of a TDM extraction circuit, No. 4
5 is a timing chart showing an example of the output signal of the keyboard scanning circuit according to the present invention, FIG. 5 is a side view showing an example of the touch signal detection device according to the present invention, and FIG.
The figure is a configuration explanatory diagram showing another embodiment of the present invention. 1... Keyboard circuit, 2... Keyboard scanning circuit, 4...
Gate circuit, 5... musical tone signal generator, 6... octave shift control circuit.

Claims (1)

[Claims for Utility Model Registration] A keyboard consisting of a plurality of keys, detecting keying accompanying key press operations on the keyboard, outputting a keying signal for each key, and generating a predetermined keying signal based on the key press operations on the keyboard. a key operation detecting means for detecting a key touch of greater strength or depth and outputting a key touch signal; a musical tone signal generating means for generating a musical tone signal corresponding to the keying signal output from the key operation detecting means; The electronic device is characterized by comprising octave shift control means for individually changing and controlling the octave of each musical tone signal generated by the musical tone signal generating means using corresponding key touch signals output from the key operation detecting means. musical instrument.