JPS604236Y2 - electronic musical instruments - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electronic musical instrument, and particularly to an electronic musical instrument having a circuit for adding a sostenuto effect to a musical tone.

In general, electronic musical instruments charge a capacitor with a voltage corresponding to the pressing speed of the key when a key is pressed, and use the discharging characteristics of the capacitor through a predetermined resistance to apply an envelope to the sound source signal created by the sound source circuit. When the key is released, a discharge gate provided separately from the discharge circuit is opened to rapidly discharge the charge remaining in the capacitor, thereby cutting off the musical tone.

Such a damper effect adding device for an electronic musical instrument is provided with a damper switch that sends a signal to continue closing the discharge gate that rapidly discharges the charge of the capacitor, and presses an appropriate number of damper switches according to the performance to smoothly attenuate the musical sound. It has become.

This damper effect adding device is designed to smoothly attenuate all scale notes that are pressed while the damper switch is pressed, but depending on the playing style, only specific scale notes may be smoothly attenuated. There are times when it is desired to incorporate the so-called sostenuto effect, which performs normal performance for notes other than the scale note.

This invention was made in view of the above-mentioned circumstances, and the purpose is to provide an electronic musical instrument that can realize a sostenuto effect.

For this purpose, a gate control circuit is installed for each discharge gate that rapidly discharges the charge of the capacitor that adds the envelope waveform provided corresponding to each key, and the sostenuto switch is activated at the same time as the key is pressed. When pressed, a gate control circuit corresponding to the pressed key causes only the discharge gate to remain closed even when the key is released, and only the musical tone corresponding to the pressed key is smoothly attenuated. It is something.

Hereinafter, this invention will be explained in detail based on an embodiment of the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the electronic musical instrument of this invention.

The keyboard 1 selects a musical tone of a predetermined frequency by pressing a key, and the touch of a key (pressing speed, pressing force, etc.) is detected by a touch sensor 2 arranged in relation to each key of the keyboard 1, Generates a voltage depending on the touch.

The touch sensor 2 is composed of an element that generates an electromotive force according to the strength, pressure, or speed of a touch, such as a piezoelectric element or a coil, or a photoelectric means, and the voltage generated from the touch sensor 2 is transferred to a capacitor Co. It will be charged.

The charge stored in the capacitor Co is discharged via the resistor Ro with a time constant CoRo, and the attenuated voltage of the capacitor Co is applied to the musical tone gate 4.

The musical tone gate 4 is opened and closed by a tone source signal from the tone source circuit 3, and a musical tone signal with an envelope corresponding to the discharge voltage of the capacitor Co is obtained at the output terminal OUT.

On the other hand, the capacitor CO is provided with another discharge circuit via a discharge gate G and a resistor R.

The discharge gate G is configured to open and close the circuit in response to a signal from the gate control circuit 5 (details shown in Figure 12), and the resistance R has an extremely small value compared to the resistance Ro of the discharge circuit. When the discharge gate G is opened, the capacitor Co is rapidly discharged with a time constant CoR, and the signal at the output terminal OUT is rapidly attenuated.

An example of the gate control circuit 5 is shown in FIG.

The switch SWD is a damper switch that adds a conventional damper effect, the switch SWK is a key switch that corresponds to each key, and the switch SW is a sostenuto switch that obtains a sostenuto effect.

When switch SWK is turned on by pressing the key on keyboard 1 (Fig. 1), signal 1 is sent through OR circuit OR to NOR circuit N.
OH and inverted to apply a signal 0 to the discharge gate G (FIG. 1).

Since the discharge gate G opens with the signal 1 and closes with the signal 0, the gate G is closed with the signal O and the capacitor Co (
1) is prevented from discharging through the gate G of FIG.

When the key is released, switch SWK turns off and the OR circuit OR
Since the signal applied to the discharge gate G becomes 0, the signal applied to the discharge gate G becomes 1, rapidly discharging the charge in the capacitor CO.

If the damper switch SWD is turned on at this time, signal 1 is added to the OR circuit, so even if the switch SWK is turned off by releasing the key, the NOR circuit NOR
A signal 1 is applied to , and the signal to the discharge gate (G) is set to 0.

Therefore, the discharge gate does not open even when the key is released, and the charge in the capacitor C2 is not discharged from the gate G.

This damper switch SWD is provided in common to the gate control circuits corresponding to each key, and a common signal is simultaneously applied to each gate control circuit by turning on and off the damper switches SWD.

Therefore, while the switch SWD is on, a damper effect is added to all musical tones that are pressed.

Assume that the sostenuto switch SW is turned on when the key is pressed and the switch SWK is on.

The signal applied to the differential circuit DI changes from O to 1, generating a positive pulse, which is applied to the AND circuit section via the diode D1.

Since the signal 1 due to the key depression is applied to the other input terminal of the AND circuit AN, the AND condition of the AND circuit AN is satisfied, and the signal 1 is applied to the set terminal S of the flip-flop FF, causing the output Q to become 1. Set to .

The output Q signal is sent to the discharge gate G via the NOR circuit NOR.
Therefore, unless the flip-flop FF is reset, the discharge gate will not open even if the switch SWK is turned off.

When the sostenuto switch SW is turned off, a waveform falling from the signal 1 to 0 is added to the differentiating circuit DI.

This causes the differentiator circuit DI to generate a negative pulse.

The negative pulse is inverted by the inverter I via the diode D2 and applied to the reset terminal R of the flip-flop FF.

This signal resets the flip-flop FF and sets the output Q to 0.

Note that even if the sostenuto switch SW is turned on when the key is not pressed, that is, when the switch SWK is off, the AND condition of the AND circuit AN is not satisfied, so the flip-flop FF cannot be set to 1.

Although FIG. 2 above shows an example of one gate control circuit, circuits having a similar configuration are provided corresponding to each key.

Here, the sostenuto switch SW is shared in the same manner as the damper switch SWD, and there is only one sostenuto switch SW.

FIG. 3 shows this situation in a block diagram.

Now, when the key is pressed, only the corresponding switch 5WK2 is turned on,
Assume that the sostenuto switch SW is turned on at this time.

Signal 1 when switch 5WK2 is turned on is AND circuit AN
2, and the positive pulse generated in the differentiating circuit DI2 by turning on the sostenuto switch SW is applied to the other input terminal of the AND circuit AN2 via the diode D21, so the AND condition is satisfied and the flip-flop FF is set to 1. do.

At this time, a signal 1 is applied to the other AND circuits l and AN3 to ANn by turning on the switch SW, but the signals from the switches 5WKl and 5WK3 to 5WKn corresponding to the keys are 0, so the AND conditions of each AND circuit are This is not true, and the respective flip-flops FFl, FF3 to FFn are not set.

Furthermore, even if you press another key with the sostenuto switch SW turned on, the signal from the sostenuto switch SW that is applied to each AND circuit is O, so the AND condition of each AND circuit will not hold. .

In this way, when the sostenuto switch SW is pressed, the flip-flop of the gate control circuit corresponding only to the key being pressed is set, and when the corresponding discharge gate is closed, a sostenuto effect is added. Even if another key is subsequently pressed with the sostenuto switch SW turned on, no sostenuto effect will be added to the sound corresponding to that key.

When the sostenuto switch SW is turned off, the flip-flop set by this signal is reset.

Further, according to this circuit, by turning on the damper switch SWD, a damper effect can be added simultaneously to all the notes that are pressed.

Note that the sostenuto switch is a pedal switch or a push button switch, and is placed at an appropriate location on the electronic musical instrument.

Since this invention has the above structure, it is possible to realize a sostenuto effect in which musical tones are selectively and smoothly attenuated, and an effect similar to that of a sostenuto pedal on a piano can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of an electronic musical instrument of this invention, Fig. 2 is a block diagram showing an example of a gate control circuit in the same embodiment, and Fig. 3 corresponds to each key in the same embodiment. FIG. 2 is a block diagram showing a gate control circuit. SWD...damper switch, SWK...
・Key switch, SW...Sostenuto switch, DI...Differential circuit, OR...OR circuit, AN---AND circuit, FF...・Flip-flop, NOR...NOR circuit, 5...
...Gate control circuit.

Claims (1)

[Scope of utility model registration request] An electronic musical instrument that adds an envelope to a sound source signal using the charging and discharging characteristics of a capacitor includes a sostenuto switch, a key switch that detects key depression and key release, and a key switch that detects key release when the key switch detects key release. a discharge gate for rapidly discharging the charge in the capacitor; a storage device; when the sostenuto switch is turned on and a key press is detected by the key switch, the storage device is set to a set state; An electronic musical instrument comprising, for each key, a control means for setting the storage device to a reset state by turning off a switch, and a prohibition means for prohibiting a discharging operation of the discharge gate while the storage device is set.