JP2952880B2 - Touch detection circuit for electronic musical instruments - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a touch detection circuit of an electronic musical instrument, and more particularly, to the time lapse of an initial touch of a key, that is, a press from a key press to a key release. The present invention relates to a touch detection circuit used for detecting a key state.

[Conventional technology]

Conventionally, in an electronic keyboard instrument, detection of an initial touch of a key has been disclosed in Japanese Utility Model Laid-Open No. 61-135394, "Key Switch of Electronic Musical Instrument", Japanese Utility Model Laid-Open No. 63-66897, "Switching Device of Electronic Musical Instrument", -11300 "Keyboard Touch Response Device" and others.

In Japanese Utility Model Application Laid-Open No. 61-135394, "Key Switches for Electronic Musical Instruments" and in Japanese Utility Model Application Laid-Open No. 63-66897, "Switching Devices for Electronic Musical Instruments," It is installed so that it can be closed, and the touch of the key is detected based on the time difference when each switch is closed.

[Problems to be solved by the invention]

By the way, in touch detection using two switches,
Since the time difference between each switch closed before and after depending on the depth of the key press is used, the key press state is uniform with only the ON information of the two switches, and the state during key press is quantitative. Can not know. Therefore, when the touch control is performed using the ON signal obtained by each switch, the rise control is simple regardless of the key pressed state, such as setting by virtual data according to the ON information. Further, since the key pressed state is detected based on the ON information of the two switches, the key pressed state is not determined until the ON information of the next switch arrives from the ON information of the first switch, so that the sound cannot be produced.

Accordingly, it is an object of the present invention to provide a touch detection circuit of an electronic musical instrument which can detect a continuous key depression state from key depression to key release in real time.

[Means for solving the problem]

The touch detection circuit of the electronic musical instrument according to the present invention includes a plurality of magneto-electric conversion means provided corresponding to each of the plurality of keys and generating an electromotive force representing a moving speed of the key from a change in a magnetic field by a magnet moved by the key operation. (Coil 12, 121, 122 ...)
, Provided in common for the plurality of magnetoelectric conversion means,
A detection circuit (a time constant circuit 2) for extracting a voltage change representing the moving speed of the key by the electromotive force obtained by the magnetoelectric conversion means.
2) and supply means (switches) for sequentially and selectively supplying the electromotive forces obtained by the plurality of magnetoelectric conversion means to the detection circuit.
, 161, 161, 162,..., A data fetch signal generation section 24).

Further, in the touch detection circuit of the electronic musical instrument according to the present invention, the supply unit includes a plurality of switches (161, 162,...) Connected in parallel to the respective magnetoelectric conversion units.
And a control means (data fetch signal generation unit 24) for selectively opening and closing the switches sequentially.

[Action]

In the touch detection circuit of the electronic musical instrument according to the present invention, the electromotive force indicating the moving speed of the key by pressing the key is obtained by the magnetoelectric conversion means provided corresponding to the plurality of keys. Each electromotive force is sequentially and selectively supplied to the detection circuit by the supply means. Each electromotive force is detected by a detection circuit, taken out as a voltage change representing the moving speed of the key, and the moving speed of each key is detected.

In addition, the supply means includes a plurality of switches connected in parallel to each of the magnetoelectric conversion means, and a control means for selectively opening and closing each of the switches sequentially. The electromotive force of the magnetoelectric conversion means is applied to the detection circuit.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

A plurality of keys 4 are provided on the keyboard 2 so as to be movable up and down around a fulcrum 6 in accordance with a note name, and serve as speed detecting means for detecting a moving speed of the key 4 which is moved by pressing a key. A magnetoelectric converter 8 is provided. That is, a rod-shaped magnet 10 is installed in the middle of the key 4, and a magnetoelectric converter 8 that converts a change in a magnetic field caused by the magnet 10 moved by the key depression into an electric signal is installed. The magneto-electric conversion unit 8 may be a device that converts the action of a continuous magnetic field into an electrical change, and may be configured by a Hall element, a coil, or the like. In this embodiment, the coil 12 corresponds to each key 4. Installed. As the coil 12, for example, a cylindrical coil formed of a conductor or a superconductor capable of moving the moving magnet 10 in and out is used.

At both ends of the coil 12, a switch 16 forming a closed circuit with the coil 12 is connected in parallel.
A time constant circuit 22 composed of a series circuit of a capacitor 18 and a resistor 20 so that when the coil 16 is open, a closed circuit is formed in the coil 12.
Is connected. The switch 16 is provided for each key 4, and the time constant circuit 22 may be provided for each coil 12 or commonly for each coil 12.

The switch 16 is for taking the time division key depression data from the electromotive force generated in the coil 12 in accordance with the pressed key state, from key depression to the key release, to selectively open and close by a data acquisition signal g ₀ configured, data take the signal generator 24 as a generator of the data acquisition signal g ₀ for opening and closing the switch 16 is installed in. Data capture signal g
₀ is given by a high (H) low (L) two-level switching signal, for example.

By electromotive force generated in the coil 12 in accordance with the key depression, the touch detection unit 26 to which the voltage V _r is taken as the key depression data generated in the resistor 20 is provided.

With this configuration, when the magnet 10 is inserted into the coil 12 by pressing a key and a magnetic field acts on the coil 12, an electromotive force is generated in the coil 12 by electromagnetic induction. Since this electromotive force is proportional to the magnitude of the acting magnetic field, the speed of change of the magnetic field, and the like, an electromotive force is generated in the coil 12 in accordance with the key depression state, that is, the moving speed of the key 4 due to the key depression. .

Here, the data acquisition signal g ₀ becomes L level, the second
As shown in FIG. 1A, the switch 16 is closed, and in this case, the magnet 10 is turned on as shown by an arrow X in response to the key being pressed.
When it moves to the side, the magnetic field acting on the coil 12 changes, and an electromotive force corresponding to the change in the magnetic field is generated in the coil 12, and a current i flows through the switch 16.

Then, when the data acquisition signal g ₀ becomes H level, as shown in FIG. 2 (B), the switch 16 is opened, this moment, the electromotive force generated in the coil 12 is a capacitor 18 and a resistor
In addition to the current 20, the current i flows. The capacitor 18 is charged by the current i, and a voltage _Vr representing the moving speed of the key 4 is generated in the resistor 20 according to the electromotive force generated in the coil 12.

Next, as shown in FIG. 2C, at the moment when the switch 16 is opened, when the magnet 10 separates from the coil 12 side as indicated by an arrow Y in response to a key release, it acts on the coil 12. The magnetic field changes in a direction opposite to that in the case where the key is pressed, an electromotive force corresponding to the magnetic field is generated, and the current -i is changed to the capacitor 18 and the resistance
Flows to With the capacitor 18 is charged by the current -i, the resistor 20 is the voltage -V _r generated representing the moving speed of the key 4 by the key release in accordance with the electromotive force generated in the coil 12.

Thus, during the resistor 20 from the key depression until the key release, obtained a change in the voltage V _r ~-V _r, the voltage change is continuous key 4 from the key-depression until the key release A level change occurs according to the moving state.

Then, the voltage V _r ~-V _r, the data acquisition signal in synchronism with g ₀ taken as the speed information to the touch detection unit 26, key depression representing the pressed key state from key depression to the key release continuously Data D ₀
Is obtained. That is, the key press data D ₀ is taken in a time-division manner for each key 4. Then, the key press data D ₀
Since obtained for each key 4, the key code KC representing each key 4 is depressed from the key depression data D _0, key-on signal KON representing whether during key depression, the time from the key depression to the key release Touch data TD that continuously indicates a target change is obtained by calculation.

According from such depressed key depression data D ₀ representing the state until the released continuously, it is possible to know the state of key depression developing operation and its rising state of subtle key 4 corresponding to the rendition style And expressive performance can be delicately expressed, so that the performance according to the playing style and the player's preference can be obtained, and the pronunciation can be made based on the data in the middle, and the response of the pronunciation is made faster. You can do it.

Next, FIG. 3 shows an electronic musical instrument which is an embodiment of the touch detection circuit of the electronic musical instrument of the present invention.

A touch detection circuit 30 for detecting the pressed state of each key is provided corresponding to the keyboard 2, and a key code KC, a key-on signal KON, and touch data TD are obtained from the touch detection circuit 30 when each key 2 is pressed. The key code KC, the key-on signal KON, and the touch data TD are generated in a time-division manner for each key.

Then, based on the key code KC given from the touch detection circuit 30, the tone forming circuit 32 has a tone and octave determined according to the key code KC, and forms a tone signal controlled according to the key-on signal KON. Then, a necessary tone color is given, and a tone signal in which tone components such as volume and pitch are controlled by the touch data TD is generated.

This tone signal is amplified by an amplifier 34 provided in the sound system, and then applied to a speaker 36 to be sounded as a tone.

FIG. 4 shows a specific circuit configuration example of the touch detection circuit 30 in the electronic musical instrument shown in FIG.

.. Are provided with a plurality of channels corresponding to the plurality of keys 41, 42... Installed on the keyboard 2, and the keys 41, 42. The magnet 10 attached to is installed so as to be able to enter and exit. That is, in this embodiment, the switches 161 and 162.
..The coils 121 and 1 are connected in parallel and
Are connected in parallel to a time constant circuit 22 including a capacitor 18 and a resistor 20. Therefore, when the switches 161, 162... Are selectively opened, each coil 12
Voltage V _r ~-V _r corresponding to the electromotive force generated in 1,122 ... are taken through a resistor 20.

The data capture signal generator 24 includes switches 161 and 162.
The data acquisition signals g _1, g ₂ ··· g _N for opening and closing at a certain time division time slot, generated on the basis of the output signal from the counter 38. The counter 38 forms frequency dividing means for dividing the frequency of the clock signal φ generated by the clock signal generating circuit 50 as a reference signal for data processing.

Analog-to-digital converter (A / D) 52, each key 41, 42, ... of the pressed key state has occurred across the resistor 20, i.e., the voltage V _r ~-V _r representing the key depression or key release it is an analog signal into a digital signal from the convenience of data processing a variation of the voltage V _r ~-V _r relative to the clock signal phi.

Then, the key-on signal forming circuit 60 generates the keys 41, 42,.
Each key 41, 42 ... from the digitized voltage V _r ~-V _r obtained for each & generates a key-on signal KON representing whether or not being depressed.

That is, the key-on signal forming circuit 60, first and second comparators 602, 604 are installed, depressed reference level R ₁ representing the key depression is set in the comparator 602, also to the comparator 604 It is set key release reference level R ₂ representing the key release. The key depressing reference level R ₁ represents the lowest level to be judged as a key depressed state, and the key release reference level R ₂ represents the lowest level to be judged as a key depressed state. For example, as shown in FIG. Set to positive / negative side. Therefore, the voltage V _r obtained during key depression exceeds a depressed reference level R _1, comparator 602 generates an H output representing the in depressed, a voltage -V _r obtained upon key release
There below the key release reference level R _2, comparator 604 generates an H output representing the key release.

The output of the comparator 602, is applied to the AND circuit 606 and the data acquisition signals g _1, also data acquisition signal g ₂ and logical product is taken is applied to the AND circuit 608. And each coil 121, 1
A plurality of SR flip-flop circuits (SR
−FF) 621, 622... Are installed, and the output of the AND circuit 606 is
The set input S of SR-FF621 and the output of AND circuit 608 are SR-FF6
It is added to 22 set inputs S. The output of the comparator 604 is applied to the AND circuit 610 and the data acquisition signals g _1, also data acquisition signal g ₂ and logical product is taken is applied to the AND circuit 612. The output of the AND circuit 610 is applied to the reset input R of the SR-FF621, and the output of the AND circuit 612 is applied to the reset input R of the SR-FF622. And each SR-FF621, 622 ...
Is obtained as a key-on signal KON indicating that each of the keys 41, 42... Is being pressed, and is extracted through the OR circuit 614.

The key code KC is obtained by ANDing the key-on signal KON with the output obtained by the counter 38 and the AND circuit 70.

The touch data forming circuit 80 forms the touch data TD representing the pressed key state continuous from the voltage V _r ~-V _r representing the key depression or key release. That is, the touch data forming circuit 80 includes a plurality of AND circuits 80 corresponding to the coils 121, 122,.
1, 802... Are provided, and in the AND circuits 801, 802.
/ D52 voltage V _r ~-V _r and the data acquisition signal g ₁ from, g ₂ ··· g _N
And is taken. The outputs of the AND circuits 801, 802,... Are added by the accumulators 811, 812,..., And the added output is held in each of the latch circuits 821, 822,.
Therefore, in each of the accumulators 811, 812,..., The final addition data held in each of the latch circuits 821, 822,.
.. Hold the added data. Also, each AND
The outputs of the circuits 801, 802 ...
Counters 841, 842 installed as frequency dividing means via
, And the output of each counter 841, 842,... Represents time data. In each of the division circuits 851, 852,..., The division is performed using the numerator of the final addition data held in the latch circuits 821, 822,. Thus, a voltage change per unit time is obtained. The outputs K ₁ , K 2... Obtained at the outputs Q of the SR-FFs 621, 622. , And each of the accumulators 811, 812... And each counter 84
1, 842 ... are reset, and each accumulator 811, 812 ...
, And the respective operations of the counters 841, 842,... Are started from the arrival of the key-on signal KON of the pressed keys 41, 42,.

Then, each key 4 obtained by each of the division circuits 851, 852,...
The touch data TD for each of 1, 42,... Is extracted through the OR circuit 860.

With this configuration, the clock signal generation circuit 50
Generates a clock signal φ shown in FIG. 6A, and a counter 38 generates a frequency-divided pulse having a pulse width of one cycle of the clock signal φ. The data acquisition signal generator 24 sets a specific time-division time slot in synchronization with the output pulse of the counter 38, as shown in FIG. 6B, and operates the keys 41, 42,. In order to take in the data based on the key, as shown in C, D and E of FIG.
Data acquisition signals g ₁ , g _2, ..., G _N having pulse widths of the time-division time slots set corresponding to.

Here, for example, when the key 41 of the keyboard 2 is pressed, the magnet 10 is inserted into the coil 121 in accordance with the movement of the key 41. As a result, an electromotive force generated in the coil 121, the switch 161 by the data acquisition signal g ₁ is opened in a time division time slot, a capacitor 18 and a resistor by the electromotive force 20
, A voltage _Vr is generated in the resistor 20. This voltage
_Vr is converted to a digital signal by the A / D 52. The voltage V _r is, exceeds the key depression reference level R _1, comparator 602 generates an H output. The AND circuit 606, logical product of the output and the data acquisition signal g ₁ of the comparator 602 is taken, H output of the AND circuit 606 obtained by the establishment of the logical AND SR-FF
Is applied to the set input S of the 621, and the output Q of the SR-FF621 becomes H
Move to the level. This H level indicates the rise of the key-on signal KON representing the key 41 being pressed.

At this time, the output of the comparator 602 is also applied to the AND circuit 608, since there is no data accepting signal g _2, the logical product of the AND circuit 608 does not hold. Therefore, SR-FF622 maintains the reset state, and output Q is at L level. If the keys 41 and 42 are pressed at the same time, of course,
Since the logical product of the AND circuit 608 is established, the output Q of the SR-FF622 also shifts to the H level.

When the key 41 is key release, the resistor 20, since the reverse polarity voltage -V _r is generated, the voltage -V _r is likewise A / D52
Are A / D converted and compared by the comparator 604. This voltage −V _r
There becomes higher than the key-off reference level R _2, comparator 604 generates a H output, holds the logical product of the data take signals g ₁ the AND circuit 610, SR-FF621 is reset. As a result, the output Q of the SR-FF621 shifts to the L level, which indicates the fall of the key-on signal KON. Therefore, the key-on signal KON is set from the point in time when the SR-FF621, 622... Are set to the point in time when they are reset in accordance with the continuous voltage change from the key depression to the key release of each key 41, 42. Is given by a pulse having a time width of H level.

In the AND circuit 70, the key-on signal KON and the counter 38
Of the keys 41, 42, ...
Is formed.

On the other hand, the voltage V _r, the data capture signal g ₁ is added to each AND circuits 801, 802, ... of the touch data forming circuit 80, g ₂ ·
· Logical between g _N is taken, while the voltage V _r is present, the keys 41, 42 ... and the data acquisition signal depressed
Each AND circuit 8 for which a logical product has been established corresponding to g ₁ , g _2, ... g _N
The H output is obtained from 01, 802,. Each accumulator 811, 81
2 and the reset inputs of the counters 841, 842,..., Output K ₁ , K _2.
Are added, and each accumulator 811, 812 ... and each counter 841, 842
Is reset, and the previous data is deleted when the key is pressed. The outputs of the AND circuits 801, 802,... Are added to the accumulators 811, 812,.
Are held in each of the latch circuits 821, 822,..., Each accumulator 811, 812,.
The outputs of the circuits 801, 802 ... and the respective latch circuits 821, 822 ...
Is added to the final accumulated data held in the latch circuits 821, 822,... As accumulated data.
・ It is held in This accumulating operation is performed continuously in the time-division time slot section, and increases in response to a change in the voltage _Vr . The output of each AND circuit 801, 802 ...
Are counted by the counters 841, 842,. In each of the division circuits 851, 852 ...
821 and 822 accumulate the data held in the.. Is divided by the count value of each counter 841 and 842, ..., touch data TD representing the temporal change of the voltage V _r is calculated.

The touch data TD is obtained from the division circuits 851, 852,... For each key 41, 42,. Then, the touch data TD is obtained in synchronization with the key-on signal KON, and represents a key depression state from the start of key depression to the key release.

As described above, the key-on signal KON, the key code KC, and the touch data TD are provided for each key 41, 42 for each time-division time slot.
.. Corresponding to... F, G, H in FIG.
D ₁ , D ₂ ... D _N
In 32, it is used for controlling tone generation components such as tone control and volume and tone. The tone signal obtained by the tone forming circuit 32 is amplified by an amplifier 34 and then emitted from a speaker 36 as a tone.

Since the touch data TD represents a continuous key depression state from key depression to key release, the rising shape of the tone signal can be controlled by the pattern of the touch data TD, so that the playing style and the A delicate touch expression according to the player's preference can be performed, and furthermore, the sound can be generated with data in the course of key depression, so that the response to the generation can be accelerated.

Further, since the key depression data D ₀ underlying touch data TD to obtain a key-on signal KON representing the key depression or key release, is determined uniquely and touch data TD and the key-on signal KON, uttered from the key-depression Responsiveness to is improved.

〔The invention's effect〕

As described above, according to the present invention, the following effects can be obtained.

(A) Touch detection can be performed in real time based on the continuous movement speed of key operation, key press data of each key can be extracted in a time-division manner, and tone control can be performed in accordance with key press data of each key. Delicate touch expression according to the playing style and player's preference, etc., as well as sounding control according to the key pressing state during key pressing, speeding up response to sounding it can.

(B) Since the change in the magnetic field accompanying the movement of the magnet that moves according to the key depression of each key is detected by the magneto-electric conversion means, and the electromotive force obtained by the key depression by the magneto-electric conversion means is extracted through the time constant circuit. , It is possible to obtain a voltage change representing the key pressing speed, and to reliably detect a continuous key pressing state from key pressing to key release,
Key press data representing a delicate touch expression according to the playing style, player preference, and the like can be extracted.

(C) Since the detection circuit can be shared by a plurality of magnetoelectric conversion units, the configuration can be simplified.

[Brief description of the drawings]

1 is a circuit diagram schematically showing an embodiment of a touch detection circuit of an electronic musical instrument according to the present invention, FIG. 2 is a circuit diagram showing an operation of the touch detection circuit of the electronic musical instrument shown in FIG. 1, and FIG. 4 is a block diagram showing an embodiment of the electronic musical instrument using the touch detection circuit of the electronic musical instrument shown in FIG. 1. FIG. 4 is a specific circuit configuration example of the touch detecting circuit in the electronic musical instrument shown in FIG. FIG. 5 is a diagram showing a key press or key release reference level set in the comparator of the touch detection circuit shown in FIG. 4, and FIG. 6 is a diagram showing the touch detection circuit shown in FIG. It is a figure showing an operation. 2 ... keyboard 4, 41, 42 ... key 8 ... magneto-electric conversion unit 10 ... magnet 12, 121, 122 ... coil (magnetic-electric conversion means) 16, 161, 162 ... switch (supply means) 22 ... Time constant circuit (detection circuit) 24 Data capture signal generator (supply means, control means) 26 Touch detection section 30 Touch detection circuit

Claims (2)

(57) [Claims] 1. A plurality of magneto-electric conversion means provided corresponding to each of a plurality of keys and generating electromotive force indicating a moving speed of the key from a change in a magnetic field by a magnet moved by a key operation; A detection circuit that is provided in common to the conversion means and extracts a voltage change representing the moving speed of the key by the electromotive force obtained by the magnetoelectric conversion means, and sequentially outputs the electromotive forces obtained by the plurality of magnetoelectric conversion means. A touch detection circuit for an electronic musical instrument, comprising: a supply unit for selectively supplying the touch detection circuit to the detection circuit. 2. The apparatus according to claim 1, wherein said supply means comprises a plurality of switches connected in parallel to said magnetoelectric conversion means, respectively, and control means for selectively opening and closing said switches sequentially. Item 2. A touch detection circuit for an electronic musical instrument according to item 1.