JPS5855514B2 - Touch response keying device for electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a touch responsive keying device for an electronic musical instrument.

In standard key-operated electronic musical instruments, different tonal signals are produced by depressing individual selectable keys on a keyboard.

However, the magnitude of these tone signals is constant and independent of the pressing blade applied to the key.

In this type of musical instrument, it has become common to use a separate manual volume control to globally vary the tone signal level.

This standard keyboard electronic musical instrument cannot give the player the same feeling when hitting a key as a hammer hits a string when a key is pressed down on a non-electronic keyboard instrument.

Moreover, this type of instrument cannot provide output tonal signals with different peak amplitudes.

Prior art touch-responsive devices typically employ circuitry to provide controlled closure of a manual switch,
The above disadvantages are overcome by generating a voltage to control the circuit.

This control voltage depends on the speed of contact closure.

Other prior art devices provide control signals by depressing a key and causing a magnet to pass through an associated coil.

However, in the above and other prior art devices,
The correlation between the force acting on the key and the initial amplitude level of the tonal signal output and the variable attenuation slope of the subsequent tonal signal amplitude obtained by mechanical damping in non-electronic musical instruments cannot be simulated.

Additionally, magnetic touch responsive devices are often difficult and expensive to construct due to tight flux gap tolerances in the magnetic circuit.

The device of the present invention was invented in view of the drawbacks of the conventional devices mentioned above.

The touch-responsive keying device of the present invention includes a mechanism that generates an AC voltage signal with a peak amplitude corresponding to the pressing blade applied to the key, and a mechanism that generates an output control voltage in response to this AC signal to correspond to the selected key. and circuit means for regulating the amplitude of the tone signal output by this voltage.

The mechanism for generating the alternating current signal consists of a velocity responsive transducer and a high frequency signal source connected to the transducer.

The speed converter consists of a force relay mechanism and a variable capacitor section.

The variable capacitor section consists of a U-shaped movable capacitor plate and a fixed capacitor plate made of Mylar or the like having a conductive coating layer.

The fixed capacitor plate is located within a groove formed in the U-shaped movable capacitor plate.

The movable capacitor plate is connected to a force relay mechanism responsive to key presses.

In the rest position, the movable capacitor plate has no effective overlap with the conductive coating of the fixed capacitor plate.

When the key is depressed, the coupling means of the force relay mechanism moves the U-shaped movable capacitor plate in a direction that overlaps the conductor portion of the fixed capacitor plate.

As the force acting on the key increases, the movement of the U-shaped movable capacitor plate in the direction of the overlapping position increases.

A high frequency signal source is connected to this movable capacitor plate, which is connected to circuit means for producing a control voltage.

The degree of overlap of the plates is related to the capacitance of the speed transducer and the pusher blade acting on the key.

In response to a change in the capacitance value of the speed converter, the maximum amplitude of the high frequency alternating current signal flowing to the circuit means changes proportionally.

This alternating current signal is received by circuit means, which comprises a variable impedance input switch circuit, which passes only one polarity.

The variable impedance circuit output is rectified and stored.

The stored voltage exits through a double slope discharge circuit consisting of separate branches with different discharge rates.

The discharge voltage envelope is applied to a keyer circuit to control the amplitude of the tone signal.

The discharge branch circuit through which the stored voltage flows depends, in part, on the position of the key.

An object of the present invention is to provide a touch responsive device that controls the level of a tone signal generated in response to a selected key.

Another object is to provide a mechanism that generates a signal proportional to the depressing blade acting on the key and that simulates the operation of a standard non-electronic musical key.

Yet another object is to use a variable capacitance transducer that passes a signal proportional to the pusher blade acting on the key and transmitted to the movable plate of the capacitor.

Still another object is to provide a variable capacitor that includes a movable plate and a fixed plate and does not require strict dimensional accuracy during manufacture and assembly.

Still another object of the present invention is to provide a circuit for generating an output signal envelope for controlling the level of a tone signal corresponding to a pressed key in response to a signal proportional to the position of the key and the pressed blade acting on the J key. It is to be.

Other objects will become apparent from the following detailed description of specific embodiments, taken in conjunction with the accompanying drawings.

In the drawings: FIG. 1 is an illustration showing a touch-responsive mechanism including a variable capacitor in a rest position and a fully engaged position.

FIG. 2 is a cross-sectional end view showing a variable capacitor in which a fixed capacitor plate is located within a U-shaped groove of a movable capacitor plate.

FIG. 3 is a circuit diagram showing the circuit means for generating signals for controlling the keyer circuit.

A standard music keyboard has a plurality of parallel keys arranged in musical notation order from one end of the keyboard to the other.

As shown in FIG.
It is connected to.

The key 11, shown schematically in FIG. 1 for simplicity, may be provided in any conventional manner.

For example, the key is fixed to the frame of the musical instrument so as to be rotatable about a fulcrum to maintain the key in a substantially horizontal neutral position.

When key 11 is pressed down, it activates standard keyboard contacts K, as schematically shown in FIG.
engage.

That is, when the key 11 is pressed down, the key contacts the free end of the cantilever member 12 and depresses it.

The other end of the cantilever member 12 is fixed to the base 13 of the touch response mechanism 10.

An L-shaped drive member 14 is rotatably fixed to the free end of the cantilever member 12.

The L-shaped drive member 14 is pivotally mounted at the connection of its horizontal and vertical legs.

The contact rod 15 is attached to the base 13.

The contact rod 15 extends vertically outwardly and is connected to the single-shaped drive member 14.
It is located slightly below the horizontal leg of.

Passive block 16 is attached to one end of movable capacitor plate 17.

The movable capacitor plate 17 is pivotally attached to the substrate 13 at a movable capacitor plate pivot point 18 .

This movable capacitor plate 17 forms a protruding U-shaped groove.

The surface 19 of the passive block 16 is a specially curved surface.

A fixed capacitor plate 20 is fixed to an insulating mounting plate 21.

The insulating mounting plate 21 fixed to the base 13 slightly separates the fixed capacitor plate 20 from the base 13.

Base 13 and fixed capacitor plate 20 are therefore located in parallel planes.

The fixed capacitor plate 20 consists of two mylar sheets 22 or a non-conductor and a conductor 23 interposed between them.

Therefore, the conductor 23 is covered with mylar sheets 2 on both sides.
2.

The electrical conductor 23 forms a pattern, which in the preferred embodiment is generally T-shaped.

Fixed capacitor plate 20 is located within a groove formed in movable capacitor plate 17, as shown in FIG.

An input signal source is electrically connected to the long fingers of the conductor 23.

A coil spring 24 is connected between the movable capacitor plate 17 and an extending terminal 25 fixed to the insulating mounting plate 21.

This coil spring 24 assists in returning the movable capacitor plate 17 to a neutral or released position.

In this position, the movable capacitor plate 17 is locked to the support member 26, as shown by the solid line in FIG.

The coil spring 24 described above has electrical conductivity and constitutes a signal path from the movable capacitor plate 17 to the extension terminal 25.

This extension terminal 25 is connected to the circuit means implied in FIG.

The input and output connections of the speed converter can be reversed without any change in performance.

A leaf spring 2γ is fixed to the base 13 above the movable capacitor plate 17 and the head of the conductor 230.

One end of the leaf spring 27 is attached to the base 13 at a ledge 28 above the movable capacitor plate pivot point 18.

The leaf spring 27 extends in a downwardly sloping manner, and its free end is located on the support protrusion 29 .

The supporting protrusion 29 is attached to the base 1 slightly below the first stop member 30.
It is fixed at 3.

The first stop member 30 is similarly fixed to the base 13.

The second stop member 31 is attached to the base 13 above the first stop member 30 at the midpoint of the length of the leaf spring 27 .

When the player presses down the key 11, the cantilever member 12 is moved down.

Since the single-shaped drive member 14 is rotatably attached to the cantilever member 12, the double-shaped drive member 14 also moves downward.

During this downward movement, the horizontal leg of the single-shaped drive member 14
Contact 5.

Due to this contact, the single-shaped drive member 14 begins to rotate counterclockwise about the pivot point to the cantilever member 12 .

Due to this rotation, the vertical leg of the single-shaped drive member 14 comes into contact with the passive block 16 with an arcuate sliding movement.

Since the face 19 of the passive block is inclined downward, it complements the sliding movement of the single-shaped drive member 14, and after the downward movement of the key 11 is completed and the iron iron 11 is released. This ensures smooth disengagement and return of the single-shape drive member 14.

The smooth rounded contact surface of the vertical leg of the single-shaped drive member 14 and the surface 19 of the driven block 16 act as a cam surface.

In this way, the pressing blade attached to the key 11 is the passive block 16.
is proportionally transmitted to the movable capacitor plate pivot point 1.
Move down around 8.

The movable capacitor plate 17 is locked to the support member 26,
As a result, the passive block 16 is positioned slightly inclined upward from the horizontal direction.

Depending on the angle of the passive block 16 and the inclination of the surface 19,
The contact area between the single-shaped driving member 14 and the passive block 16 is set.

This area is proportional to the amount of energy or force transferred.

Passive block 1 attached to movable capacitor plate 17
6 is moved downward around the movable capacitor plate pivot point 18,
The U-shaped groove portion of the movable capacitor plate 17 is moved upward.

In the rest or neutral position, the U-shaped groove portion is located a distance below and from the head of the electrical conductor 230 of the fixed capacitor plate 20.

As the U-shaped groove portion moves upward, this portion begins to overlap the head of the electric body 23.

Fixed capacitor plate 30 and movable capacitor plate 17 constitute variable capacitor 32.

As the U-shaped groove portion of the movable capacitor plate 17 continues to move upward, the overlap increases and the plate area of the overlap between the fixed capacitor plate 20 and the movable capacitor plate 17 increases.

As this area increases, the capacitance value increases.

The capacitance (q) of the above capacitor is expressed by the following formula.

ε0: dielectric constant S: plate area dl, d2: distance between both sides of the fixed capacitor plate 20 and both inner surfaces of the movable capacitor plate 170 The conductor 23 of the fixed capacitor plate 20 is a Mylar sheet 2
2 and inserted into the U-shaped groove portion of the movable capacitor plate 17 to prevent short-circuiting of the capacitor due to contact of conductive parts.

Furthermore, since the conductive portion of the movable capacitor plate 17 is U-shaped as shown in FIG. 2, d1+d in the above equation
The value of 2 is constant.

If the mylar sheet 22 is located in the center of the U-shaped groove section, the distances d1 and d2 from each surface of the mylar sheet 22 to each inner surface of the groove are equal, and the sum of these distances satisfies the above capacity equation. The value becomes d1+d2.

If the mylar sheet 22 is located off-center in the U-groove section, one of the distances to the inner surface of the U-groove will decrease and the other will increase by a corresponding amount, thus reducing the total distance d1-d2 is constant.

Therefore, the values of d and d2 in the above capacitance equation are determined by
Due to the configuration in which dl and d2 are inserted, it is impossible for the values of dl and d2 to differ greatly from each other, so that they do not vary greatly.

This configuration of variable capacitor 32 can be manufactured and assembled without extreme tolerance limitations.

As mentioned above, since the main variable in the above capacitance equation is the plate area, as the movable capacitor plate 17 moves upward, the area of overlap with the fixed capacitor plate 20 increases, and the variable capacitance value changes accordingly. increases.

As the value of the variable capacitance increases, the peak amplitude of the high frequency input signal passed by the variable capacitor 32 increases.

When key 11 is pressed down with a soft or slow touch,
The same mechanical actuation as above takes place.

However, since the upward movement of the U-shaped groove portion of the movable capacitor plate 17 is not large, no overlap with the head of the conductor 230 of the fixed capacitor plate 20 occurs.

Since the thin finger portion of the conductor 23 is simply for electrical connection with the input signal source, this portion does not actually affect the value of the variable capacitance.

In the case of this soft-touch operation, the variable capacitor 32 does not pass high-frequency signals to the input side of the circuit means, and only the standard keyboard contacts K are closed.

This is independent of the degree of depressing blade acting on the key 11, but activates the circuit means.

When the key 11 is depressed with sufficient force to create a complete overlap between the head of the conductor 230 of the fixed capacitor plate 20 and the U-shaped groove portion of the movable capacitor plate 17, the variable resistor has a maximum value. passes the maximum peak amplitude of the high frequency input signal to the input side of the circuit means.

As the magnitude of the force applied to the key 11 varies between the two limits mentioned above, an overlap of intermediate amounts occurs and the value of the variable capacitor 32 changes proportionally.

Thus, the peak amplitude of the high frequency input signal passed by the variable capacitor 32 is proportional to the pressing blade applied to the key 11.

When the U-shaped groove portion of the movable capacitor plate 17 moves upward, this portion contacts the leaf spring 27 before it overlaps the head of the conductor 330.

The leaf spring 2T exerts some mechanical restraint on this U-shaped arm.

The leaf spring 27 moves upward until its free end abuts the first stop member 30 .

Leaf spring 27 deflects at the midpoint of its length under continued upward pressure from movable capacitor plate 17.

The leaf spring 27 is deflected in this state until the intermediate point contacts the second contact member 31, and the second contact member 31 prevents upward movement.

Thus, during upward pivoting, leaf spring 27 exerts three different amounts of restraining force on the U-shaped portion of movable capacitor plate 17.

Leaf spring 27, which initially acted to retard the upward movement of movable capacitor plate 17, changes its action and biases movable capacitor plate 17 downward toward a neutral or rest position.

Return coil spring 24 and gravity assist in the downward pressure of leaf spring 27 against movable capacitor plate 17 .

All contact surfaces are covered by buffers 33 to reduce noise.

Thus, a touch-responsive mechanism consisting of a force relay element and a variable capacitance transducer simulates the operation of a musical instrument such as a piano.

The downward pressure on the key 11 is relayed to upwardly move an element similar to a hammer that strikes the strings of a piano, which is propelled towards a downward resting position in the same way as by the reaction force of the piano strings. be done.

In FIG. 3, pressing down on a key of a standard electronic musical instrument closes the normally open keyboard contact K between % and the end of the downward movement.

Each time the key is depressed, the contacts close and a predetermined voltage signal is applied to the rest of the circuit.

Separate and independent of this contact closure or variable force applied to the key, the voltage signal described above is separate from the signal described above with reference to FIG.

The push blade applied to the key causes the variable capacitor 32 of the touch response mechanism 10 to pass a high frequency signal having a peak amplitude proportional to this force, as described above.

The input signal source is a high frequency Hartley oscillator 50.

Any oscillator capable of generating a signal in the ultrasonic range can be used.

The AC signal output of the speed converter 51 including the variable capacitor 32 is connected to the transistor 53 via the isolation resistor 52 as an input.
Applied to 0 base.

The collector of the transistor is grounded via a resistor 54.

The connection point between the collector of the transistor 53 and the resistor 54 is
It is connected to the cathode of diode 55.

The emitter of transistor 53 is connected to a negative voltage source, preferably -28V, and to the base via resistor 49.

Normally, transistor 53 is non-conductive.

The negative half cycle of the AC signal applied to the base of transistor 530 through variable capacitor 32 of speed converter 51 does not affect the conductivity of transistor 53, which is in a non-conducting state.

A positive half cycle of the input signal switches transistor 53 into conduction.

When transistor 53 is conducting, the collector-emitter impedance is low and a negative voltage signal at the emitter is applied to the low impedance of the collector-emitter circuit.

As explained with reference to Fig. 1, the push-down blade for the key is
The degree of overlap of plate areas in the variable capacitor 32 is determined.

As the capacitance value of this capacitor increases, the transistor 5
The peak amplitude of the high frequency signal applied to the base of 3 increases.

If there is no overlap of the plates of variable capacitor 32, there is no signal entering transistor 53.

When the plates of the variable capacitor 32 are completely overlapped, the voltage is approximately -15V.
A high frequency signal having a peak amplitude of
Applied to 0 base.

When the peak amplitude of the input signal varies between the above maximum and minimum values, the conduction state of transistor 53 varies proportionally between a normal non-conduction state and a fully conductive state with low collector-emitter impedance. do.

Correspondingly, the magnitude of the negative voltage signal applied to the cathode of diode 55 varies between zero and -28V.

The anode of the diode 55 is grounded through a capacitor 56 and connected to a keyer circuit 57 through an isolation resistor 58.

A tone signal generator 59 is connected to the keyer circuit 57 in a well-known manner to generate a tone signal output corresponding to the key pressed by the player.

The tone signal generator 59 and the keyer circuit 57 have a standard configuration in the art and form a tone circuit, but detailed explanation will be omitted.

The standard keyboard contact has an open terminal X connected to a negative voltage source of -28 .

A switch side terminal Y of the contact point is connected to a voltage dividing circuit 60.

This voltage dividing circuit 60 consists of a resistor 61 and a grounded resistor 62.

The ratio of the resistance values of the resistor 61 and the resistor 62 is about 2:1.

The connection point between the resistor 61 and the resistor 62 is A.

Shock parallel branch circuit 63 is connected between points A and D, but the point is between the anode of diode 55 and capacitor 56.

The shock parallel branch circuit 63 includes a capacitor 64 and a discharge resistor 6.
5 and a diode 66.

Capacitor 64 is connected to point A.

When contact K closes, the voltage signal reduced by voltage divider circuit 60 is stored in capacitor 64 .

In the preferred embodiment, the voltage at point A is -10
■It is.

Capacitor 64 is charged to -10V.

The cathode of diode 66 is connected to capacitor 64 and passes a negative voltage signal when forward biased.

The low value discharge resistance 65 is a capacitor 64 and a diode 6.
6 and is grounded, providing a rapid discharge path for the capacitor 64.

Since the capacitor 64 discharges extremely quickly via the discharge resistor 65, a signal pulse of -IOV is given each time the keyboard contact K is pressed down, regardless of the speed of the pressing operation.

Point A of voltage divider circuit 60 is connected to point C via isolation resistor 67.
It is connected to the.

A first discharge parallel branch circuit 68 is connected between point C and point C, and this parallel circuit acts as a discharge path for the capacitor 56.

This first discharge parallel branch circuit 68 connects the point C and the diode 7.
It consists of a resistor 69 connected to the anode of 0.

The cathode of diode 70 is connected to the dot.

Point C is connected to the anode of isolation diode 71.

The cathode of the diode 71 is connected to a foot pedal circuit 72.

The second discharge parallel branch circuit 73 is connected to a midpoint between the switch and the capacitor 56 .

The second discharge parallel branch circuit 73 acts as a discharge path for the capacitor 56 and consists of a resistor 74 connected to the light and foot pedal sustain circuit 72.

Resistor 74 has a much larger resistance value than resistor 69.

The foot pedal continuation circuit 72 has switch contacts 76 and 77 that are operated by pressing down a foot pedal (not shown).
It consists of a connection switch 75 having a

In normal conditions, the contact 76 is connected to the cathode of the diode 71 and grounded via the terminal S.

Contact 77 is connected to resistor 74 and grounded via terminal M and potential setting variable resistor 78.

Potential setting variable resistor 78 is desirably connected to a negative voltage source of -10.

When the foot pedal is pressed down, the contact 76 is connected to the diode 7
The cathode 1 is preferably connected to a negative voltage source of -10V via the terminal T, and the contact 77 grounds the resistor 74 via a potential setting variable resistor 79.

Potential setting variable resistor 79 is preferably connected to a second negative voltage source of -iov.

Each potential setting variable resistor 78 and 79 can be adjusted to different setting values, and each terminal M.

Vary the negative voltage at N, thus maintaining a constant decay slope of the voltage stored on capacitor 56 under all conditions.

The operation of the circuit means of FIG. 3 depends on the input signal from the speed transducer 51 and the closure of the keyboard contacts.

If the key 11 is pressed down with minimal force and a soft touch so that the plates of the variable capacitor 32 do not overlap, no high frequency signal will be generated passing through the variable capacitor 32 to the base of the transistor 530.

However, regardless of the force applied, each time the key 11 is depressed, the contacts close and a negative voltage signal of -28V is applied to the voltage divider circuit 60.

In this case, approximately -10V is applied to point A due to the 2:1 resistance value ratio of resistor 61 and resistor 62.

Capacitor 64 is thus charged to -10V and diode 66 is forward biased, thereby providing a negative signal.

This -10V signal is stored in capacitor 56.

The capacitor 64 is quickly discharged via the resistor 65, and when the contact K is closed by pressing the key 11, it is charged again to -10V.

The negative voltage stored in the capacitor 56 begins to discharge, and the envelope of the discharged voltage is applied to the keyer circuit 57 to perform amplitude modulation of the tone signal generated in response to each depressed key 11.

After pressing down, when the key 11 is released, the contact K opens.

The diode 70 of the first discharge parallel branch circuit 68 is forward biased to provide a small resistance, and the capacitor 56 discharges to ground primarily via this circuit, which includes resistor 69, and resistor 67. .

A small portion of the negative voltage stored in capacitor 56 is transferred to resistor 74.
However, since the resistance value of resistor 74 is significantly smaller than that of resistor 69, the discharge of the signal via this path is minimal.

Also, since diode 55 is reverse biased and thus exhibits a significantly higher resistance to the voltage on capacitor 56, capacitor 56 does not discharge through resistor 54, which has a small resistance value.

When the key 11 is pressed down and maintained in its lowered position, the contacts will not open.

In this state, a signal of -10V remains at point A due to the voltage divider circuit 60.

Since substantially the same voltage is present at point C and point C, first discharge parallel circuit 68 is effectively excluded from the circuit as a discharge path.

Therefore, capacitor 56 is connected to the second
It is discharged via the discharge parallel branch circuit 73.

Since the resistance of resistor 74 is much higher than that of resistor 69, capacitor 56 discharges much more slowly through resistor 74 than through resistor 69.

Since the voltage discharge slopes are different, the level of the tone signal generated by the keyer circuit 5T and the tone signal generator 59 is as follows.
When the voltage is discharged through resistor 69, it decreases quickly, and when the voltage is discharged through resistor 74, it decreases slowly.

When the key 11 is pressed down with sufficient force to cause the plates of the variable capacitor 32 to overlap, a high frequency signal flows to the base of the transistor 530, and a negative voltage signal is present at the point as described above.

If the voltage provided by the variable capacitor 32 is less than the negative voltage at point A due to the closure of the keyboard contacts and the voltage divider circuit 60, the circuit as described when the speed converter 51 does not generate a signal acts.

However, if there is a greater voltage at point A than at point A due to the action of variable capacitor 320, the circuit operates as follows.

There is complete overlap between each plate of variable capacitor 32;
When the maximum peak amplitude signal from speed converter 51 flows to the base of transistor 530, transistor 53 is fully conductive and the maximum negative voltage is present.

In the preferred embodiment, the voltage of the switch is 128 cm.

A signal pulse of one IOV generated by the closure of a contact has no effect due to the above-mentioned point 28.

Therefore, a -28V signal is stored in capacitor 56.

Now, when the contact K is opened, the capacitor 56 is discharged via the first discharge parallel branch circuit 68 consisting of the resistor 69 as described above.

If contact K remains depressed, a voltage of approximately -10V will be present at point C.

Capacitor 56 discharges through first discharge parallel branch circuit 68 until 10 volts remain which is substantially negative.

At this time, since -10V exists at the light and point C,
The first discharge parallel branch circuit 68 loses its effectiveness.

The -10V charge remaining in the capacitor 56 is transferred to the resistor 74.
The discharge occurs through the second discharge parallel branch circuit 73 consisting of the following.

Therefore, the combination of the first discharge parallel branch circuit 68 and the second discharge parallel branch circuit 73 constitutes a double slope discharge circuit, and this circuit has a double slope varying at the point of -10. The envelope of the discharge voltage from 56 is given.

By employing the foot pedal sustain circuit 72, a similar effect is exerted on each discharge path, as described below.

When the key 11 is pressed down and released without involving the speed converter 51, -10V is applied to the capacitor 54 as described above.
a first discharge parallel branch circuit 6 consisting of a resistor 69;
Discharge begins through 9.

The level of the tone signal from keyer circuit 57 quickly begins to decrease.

Now, when the foot pedal is operated before the key 11 is pressed down, the contact 76 is connected to the terminal T, and a signal of -10■ flows from the forward biased diode 71.

The -10V at point C excludes the first discharge parallel branch 68 consisting of resistor 69 as a discharge path.

The contact 77 engages with a grounded terminal N via a potential setting variable resistor 79.

The charge in the capacitor 56 is discharged only through the second discharge parallel branch circuit 73 made up of the resistor 74.

Therefore, by activating the foot pedal sustain circuit T2, the slope of the voltage discharge changes, indicating a slow discharge through the resistor 74 having the higher resistance value.

The terminal N is grounded via a potential setting variable resistor 79, and the potential setting variable resistor 79 is set to a value equal to the potential setting variable resistor 78.

Separate potential setting variable resistors 78, 79 are necessary to provide the same discharge slope.

That is, the voltage at point C when contact 76 is connected to terminal S is reduced by the voltage drop across resistor 67, and as a result, the voltage at point C when contact 76 is connected to terminal T is reduced by the voltage drop across resistor 67. This is because the voltage is slightly lower than the voltage applied.

Each terminal M, N is biased to a negative voltage to provide a long decay point of the discharge voltage across resistor 74.

The first discharge parallel branch circuit 88 is grounded because the discharge through the resistor 69 is so rapid that long decay points are not taken into account.

Modifications may be made thereto by the application of common knowledge without departing from the spirit and scope of the novel disclosure of this invention;
Needless to say, there are many modifications to be made.

[Brief explanation of the drawing]

Each of the drawings shows one embodiment of the device of the present invention, of which FIG. 1 is an explanatory drawing showing a touch response mechanism including a variable capacitor in a z-rotation stop position and a fully engaged position, and FIG.
The diagram shows the U of the variable capacitor plate in a variable capacitor.
FIG. 3 is a cross-sectional view showing the positioning of the fixed capacitor plate in the shaped groove, and FIG. 3 is a circuit diagram showing the circuit means for generating the signals controlling the keyer circuit. In the drawing, 10 is a touch response mechanism, 11 is a key, 17 is a movable capacitor plate, 20 is a fixed capacitor plate, 32 is a variable capacitor, 51 is a speed converter, 68 is a first discharge parallel branch circuit, and 73 is a second discharge It is a parallel branch circuit.

Claims (1)

[Claims] 1. In an electronic musical instrument device that has a plurality of parallel keys constituting a keyboard and a tone circuit that generates a different tone output in response to the depression of each of the keys, the force that is proportional to the force acting on one of the keys is and circuit means for generating a voltage signal for controlling the tone circuit in response to the alternating current signal, wherein the touch responsive means includes an alternating current signal source means. and a link means for transmitting a pressing blade acting on one of the keys, and a capacitor means for changing a capacitance value in proportion to the pressing blade in response to the linking means, and a capacitor means for changing a capacitance value in proportion to the pressing blade, and a speed converter connected thereto, the amplitude of the alternating current signal passed by said capacitor means being proportional to the pressing blade acting on one of said keys, said circuit means responsive to said alternating signal; input impedance means for changing the value of impedance, a voltage source connected to the input impedance means, and a power storage means responsive to the input impedance means, the power storage means receiving a portion of the voltage and supplying the power storage means to the power storage means. A touch responsive keying device for an electronic musical instrument, comprising means for forming a voltage discharge envelope with two slope discharge circuits connected in parallel and discharging the voltage stored in the power storage means, and controlling the tone circuit.