JP2727992B2 - Tone control signal generator for electronic musical instruments - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone control signal generator for an electronic musical instrument which is provided in a keyboard device of an electronic musical instrument and detects a touch or an initial touch when a key is depressed and generates a signal for controlling a musical tone. Related to the device.

[0002]

2. Description of the Related Art Conventionally, as a musical sound control signal generator for an electronic musical instrument of this kind, as disclosed in Japanese Utility Model Publication No. Sho 55-4343, for example, a key frame supporting a large number of keys in a swingable manner is provided on the upper, lower, left and right sides. A shutter mechanism having a pair of shutter plates interlocked with the swing, and a pair of detectors that adjust the amount of irradiation by the pair of shutter plates of the shutter mechanism and generate an electric signal corresponding to the swing displacement of the keyboard frame are common. There is an electronic musical instrument that includes a light source and controls an arbitrary effect in an electronic musical instrument by using detection outputs from the pair of detectors as control signals.

[0003]

However, in such a conventional tone control signal generator for an electronic musical instrument, since the entire keyboard frame supported by a leaf spring is rocked, the movable portion is not provided. It is the sum of the masses of the keys and the key support member that supports those keys, and due to the large mass, the responsiveness is poor and the subtle movement that acts on the keys is detected, and the tone control corresponding to that is detected. Could not do.

Further, although it is possible to detect aftertouch after a key is depressed, it is not possible to detect the state of the start of key movement. Could not be detected. The present invention has been made in view of the above points, and has a simple structure to improve responsiveness and detect the direction of a key pressing force from the start of a key movement to an after touch and a direction of a left and right force applied to the key. To perform fine tone control.

[0005]

In order to achieve the above object, a musical tone control signal generating apparatus for an electronic musical instrument according to the present invention urges a plurality of keys upwardly by urging means so as to be swingable vertically. The key support member and the base are fixed to the key support member corresponding to each key, respectively, and from each base through the vertical flexible portion having elasticity in the key pressing direction, in the longitudinal direction of each key. A stopper member provided with an upper limit stopper and a lower limit stopper for rocking the key at the free end extending therefrom; and an upward force or displacement applied to the upper limit stopper by the urging force of the urging means and a key depression. And a sensor for detecting a downward force or displacement applied to the lower limit stopper portion and converting the detected force or displacement into an electric signal.

In the tone control signal generator for an electronic musical instrument, each key is supported by the key support member so as to be swingable in the key arrangement direction.
A key guide portion that fits into each key and regulates movement in the key array direction is provided, and a horizontal flexible portion having elasticity in the key array direction is provided. The key guide portion is connected to the stopper member through the key guide portion. It is preferable to provide a sensor that detects a force or displacement in the key arrangement direction and converts it into an electric signal.

[0007]

The musical tone control signal generating device for an electronic musical instrument according to the present invention is constructed as described above, so that when no key pressing force is applied at the time of key release, the upper limit stopper portion is controlled by the urging force of the urging means. Is applied, and the stopper member is displaced upward accordingly.

In this state, when a downward force acts against the urging force by pressing a key, the upward force applied to the stopper member is removed, and a downward force due to its own weight acts on the stopper member. After the key contacts the lower limit stopper, a key pressing force acts on the stopper member in addition to its own weight.

At this time, since the relationship between the vertical force or displacement applied to the stopper member and the time changes depending on the key pressing force and the key pressing speed, these are detected by the output signal from the sensor to perform the tone control. be able to.

Further, when a force in the key arrangement direction acts on the key and a force in the left and right direction is applied to the stopper member via the key guide portion, the force in the key arrangement direction and a sensor provided separately from the above sensor are used. By detecting the direction or displacement of the force, it is possible to perform finer tone control.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a side view showing a part of a keyboard according to a first embodiment of the present invention in cross section, and FIG. 2 is a perspective view showing only a stopper member thereof. In these figures, parts not related to the tone control signal generator are omitted.

In FIG. 1, a white key 1A and a black key 1B (hereinafter referred to as "key 1") are integrally formed of resin in a U-shaped cross section having an open lower surface, and a rear end portion of the key 1 is formed. And a projection 1a forming a key fulcrum portion is integrally provided to protrude downward.

The recesses 1b provided on the front side of the projections 1a of the plurality of keys 1 are engaged with the front edges of the through holes 2a formed in a row in the key arrangement direction of the keyboard frame 2 as a key support member. The key 1 is supported so that it can swing up and down and swing in a predetermined range in the left and right directions. The key 1 is always urged upward in the returning direction by a key return spring 3 which is an urging means interposed between each key 1 and the keyboard frame 2, and the lower surface of each side wall of the key 1 near the front end. , An L-shaped stopper piece 1c is provided vertically.

On the other hand, a base 4a of a stopper member 4 is fixedly provided on the lower surface of the front end of the keyboard frame 2 for each key. The stopper member 4 is made of an integrally molded product such as an elastic resin, and the base 4a is formed as a block-shaped rigid body.
a horizontal flexible portion 4b having flexibility in the key arrangement direction and a vertical flexible portion 4c having flexibility in the key pressing direction on the front surface
Are continuously formed. A free end extending in the longitudinal direction of each key is bifurcated, and a lower limit stopper 4d is provided on the extension of the vertical flexible portion 4c, and an upper limit stopper 4e is provided on the upper portion so as to be parallel to each other. ing.

Further, a key guide portion 5 is provided upright on the upper surface of the upper limit stopper portion 4e, and is fitted between both side walls of the key 1 so as to prevent the key 1 from moving in the key arrangement direction (lateral deflection). I have to. The stopper member 4 is configured as a cantilever beam to which the base 4a is fixed as a whole.

Then, a lower limit stopper 6A and an upper limit stopper 6B made of a cushioning material such as felt are adhered to the upper surface of the lower limit stopper portion 4d and the lower surface of the upper limit stopper portion 4e, respectively. And, by making contact with the upper limit stopper 6B, the vertical swing range of the key 1 is regulated. In addition, a subframe 7 having high rigidity and common to all keys is fixed to the lower surface of each base 4a, and the subframe 7 is positioned between the horizontal flexible portion 4b, the vertical flexible portion 4c, and the lower limit stopper 4d. The gap C is formed.

Further, a strain gauge 8A, which is a sensor for detecting a horizontal (key arrangement direction) force applied to the stopper member 4 and converting the force into an electric signal, on a vertical surface of the horizontal flexible portion 4b near the base 4a. The stopper member 4 is provided on the horizontal surface near the base 4a of the vertical flexible portion 4c.
A strain gauge 8B, which is a sensor that detects a vertical force applied to the sensor and converts it into an electric signal, is provided, and the output signals are input to amplifiers (not shown).

Next, the operation of this embodiment having the above configuration will be described. First, the relationship between the force acting on the stopper member 4 by the key depression and the elapsed time from the start of the key depression will be described.
This will be described with reference to a characteristic curve shown in FIG. In a non-key-pressed state in which no key-pressing force acts on the key 1, the key 1 is urged upward by, for example, about 60 gf by the urging force of the key return spring 3 shown in FIG. The same upward force acts on the upper limit stopper portion 4e via the stopper piece 1c of the key 1.

When the key 1 is depressed in this state, the upper edge of the stopper piece 1c of the key 1 starts to separate from the upper limit stopper 6B at time t1 from the start of key depression (0), and completely separates at time t3. During this time, the upper limit stopper portion 4e of the stopper member 4
The upward force on the key gradually decreases, and
After the time t3 when the value becomes 0gf, it becomes zero, and a downward force corresponding to its own weight acts on the stopper member 4 to displace the lower limit stopper portion 4d downward, and the distal end side of the vertical flexible portion 4c bends downward. .

When the lower edge of the stopper piece 1c of the key 1 comes into contact with the lower limit stopper 6A at time t4, if the key is depressed so as to strike, as shown in FIG. The downward force acting on the stopper member 4 rises sharply from time t4, momentarily reaches a maximum value at time t6, and then falls slightly to a value corresponding to the force due to aftertouch.

On the other hand, when the key is depressed by stroking the key, as shown in FIG. 3B, the value gradually rises from time t4, and at time t6, the value corresponding to the force by the after touch is obtained. Become. The times t1 to t6 in (b) are
The times t1 to t6 in FIG.

The slope of the rising portion from time t1 to time t3 is also steep in the former case and gentle in the latter case. Time t2 at the predetermined force level F2 between times t1 and t3 is: The elapsed times T1 and T2 between the times t4 and t6 at the predetermined force level F5 and the time t5 are shorter for the former and longer for the latter, and the key pressing speed can be detected from the elapsed time.

When the key pressing force at the time of key pressing or after key pressing includes a component in the left-right direction, the force is transmitted to the stopper member 4 integral therewith via the key guide portion 5, and The stopper member 4 bends in the key arrangement direction via the horizontal flexible portion 4b. The force acting on the stopper member 4 at that time is
The characteristic curves are almost the same as those shown in FIGS. 3A and 3B except that the characteristic curves are not related to the weight. That is, in FIG.
In (a) and (b), it is almost the same as that in which the rising portion between times t1 and t3 is removed.

Generally, a force F acting on a fixed point near the tip of a cantilevered beam such as the stopper member 4 is proportional to a bending moment M of the beam, and the bending moment M is a sectional modulus Z of the beam. The resistance change ΔR of the strain gauge disposed on the curved surface of the beam is proportional to the stress σ.

That is, assuming that a constant determined by the longitudinal elastic modulus and Poisson's ratio of the material constituting the beam is k, the following equation is obtained. M = Z × σ σ = k × ΔR

Accordingly, if the bending moment received by the strain gauge 8B shown in FIGS. 1 and 2 is represented by M and the resistance change of the strain gauge 8B is represented by ΔR, the following relationship is obtained. M = Z × k × ΔR

If the vertical force transmitted to the stopper member 4 by pressing the key is F, and the distance between the contact position between the stopper piece 1c of the key 1 and the stopper member 4 and the strain gauge 8B is D, the force is F is proportional to the key pressing force. Further, the following equation is obtained according to the force balance condition. M = F × D

From the above equations, Z × k × ΔR = F × D
And F = (Z × k × ΔR) / D. From this equation, it can be seen that the resistance change ΔR of the strain gauge B and the vertical force F acting on the stopper member 4 due to key depression are proportional.

In general, when a force F is applied to the free end of a cantilever beam, the amount of displacement of the beam in the direction in which the force F is applied is proportional to the applied force F. Therefore, the vertical displacement of the stopper member 4 is proportional to the force F, and the force F is proportional to the resistance change ΔR of the strain gauge 8B. Therefore, the output signal of the strain gauge 8B is equal to the force F proportional to the key pressing force. This is proportional to any of the vertical displacement of the stopper member 4.

Similarly, the output of the strain gauge 8A is proportional to both the force applied to the stopper member 4 in the left-right direction, which is the key arrangement direction, and the displacement of the stopper member 4 in the left-right direction. Whether the force is applied to the stopper member 4 in the left or right direction can be detected based on the sign of the output signal of the gauge 8A.

The output signals of these strain gauges 8A and 8B are input to an amplifier (not shown), then converted into digital values by an A / D converter, and input to the tone signal control means. The tone signal control means responds to the input signal,
Various controls are performed on the volume, pitch, tone, etc. of the musical tone being generated.

For example, as shown in FIG. 3A, when the rising portion at the initial stage of key depression is steep, the cutoff frequency of the low-pass filter is increased to obtain a bright tone, and FIG. As shown, when the rising portion has a gentle slope, tone color control can be performed such that the cutoff frequency of the low-pass filter is lowered to give a dark tone.

When the key is pressed strongly and quickly and the impact on the lower limit stopper 6A is large as shown in FIG. 3 (a), the reverb is made deeper, and when the impact is small as shown in FIG. 3 (b). It is also possible to control the tone to make the reverb shallower.

When a left-right force is applied to the key 1 during or after the key is pressed, the resistance value of the strain gauge 8A changes in proportion to the magnitude of the left-right force applied to the key 1, Subtle changes in sound such as shallow and fast vibrato with good responsiveness can be obtained.

According to the first embodiment, the stopper member 4
By using one strain gauge 8B disposed in the vertical flexible portion 4c, all the forces applied in the vertical direction of the key at the time of initial key press, at the end of key press, and at the time of aftertouch afterwards can be detected. Further, the force applied in the left and right direction of the key at all times during and after key depression can be detected by one strain gauge 8A disposed on the horizontal flexible portion 4b. A leftward force or a rightward force can be easily detected.

FIG. 4 shows a second embodiment of the present invention in which a part of the first embodiment is modified. The same parts as those in FIG. 1 are denoted by the same reference numerals. A detailed description of that part is omitted.

In the second embodiment, a reflecting plate 18C such as an aluminum plate is provided on the lower surface of the lower limit stopper 4d formed on the tip end side of the stopper member 4 and is opposed to the reflecting plate 18C of the sub-frame 7. A photosensor 18D in which a light emitting element and a light receiving element are
The other configuration is the same as that of the first embodiment.

With the above configuration, when the upper edge of the stopper piece 1c of the key 1 starts to separate from the upper limit stopper 6B by pressing the key, the upward force of the key return spring 3 applied to the upper limit stopper 4e gradually increases. The force is reduced to zero when completely separated. Accordingly, the lower limit stopper portion 4d of the stopper member 4 is slightly displaced downward by its own weight, and the output signal of the photo sensor 18D changes. Furthermore, the key
After the one stopper piece 1c abuts on the lower limit stopper 6A, a downward force acts on the stopper member 4 to further change the output signal of the photosensor 18D.

Also in this case, the key pressing force is proportional to the displacement of the stopper member 4 as described above, and the photo sensor 18D is used when the key is pressed so as to hit the key and when the key is pressed so that the key is pressed.
Is the same as in the first embodiment, and the strain gauge 8A, which is a sensor for detecting the force in the key array direction, is also the same as in the first embodiment.

In the second embodiment, the stopper member 4
Although a photo sensor is used as a sensor for detecting the displacement of the magnetic field, a magnetic sensor such as a magnetic lattice sensor, a magnetic resistance sensor, or a Hall effect sensor may be used, and the use of a capacitance sensor or the like may be considered. Further, in the second embodiment, the various sensors as described above may be disposed between the stopper member 4 and the fixing portion instead of the strain gauge 8A to detect the force of the key in the left-right direction. It is possible.

According to the second embodiment, the stopper member 4
Since the displacement can be detected at the tip portion having the largest displacement, the detection accuracy of the sensor can be further improved.

FIG. 5 is a side view of a keyboard according to a third embodiment of the present invention, in which a part of the keyboard is shown in cross section. In the third embodiment, a vertical flexible portion 24c having flexibility in the key pressing direction is integrally formed on the front surface of a base 24a of the stopper member 24,
The lower end stopper portion 24d is provided at the free end side of the forked portion.
And an upper limit stopper portion 24e, and the vertical flexible portion 24
The strain gage 8B is arranged near the base 24a of FIG. In this embodiment, the key frame 25 is erected by extending the keyboard frame 2 in the key tip direction, but the other configuration is the same as that of the first embodiment shown in FIG.

That is, in the third embodiment, the structure of the portion for detecting the left-right force applied to the key from the first embodiment described above is omitted, and the force in the key pressing direction can be reduced with a simple structure. Detecting the tone can be performed. In addition,
Also in the third embodiment, the displacement of the stopper member 24 at the time of key depression can be detected by the same method as in the second embodiment.

[0044]

As described above, the musical tone control signal generator for an electronic musical instrument according to the present invention is a sensor for detecting the vertical force or displacement applied to the upper and lower stopper portions of the cantilevered stopper member. Was established,
A single sensor can detect the start and end of the key movement and the state of aftertouch after that to perform various tone control with good responsiveness.

Further, the musical tone control signal generator for an electronic musical instrument according to the second aspect of the present invention further includes a sensor for detecting a force or displacement in a key array direction. The applied lateral force and its direction can also be detected, thereby enriching the performance expression.

[Brief description of the drawings]

FIG. 1 is a side view showing a part of a keyboard according to a first embodiment of the present invention in cross section.

FIG. 2 is a perspective view showing only the stopper member.

FIG. 3 is a diagram showing a relationship between a vertical force acting on the stopper member and an elapsed time from the start of key pressing.

FIG. 4 is a side view of a part of a keyboard according to a second embodiment of the present invention in cross section.

FIG. 5 is a side view showing a part of a keyboard according to a third embodiment of the present invention in cross section.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Key, 2 ... Keyboard frame, 3 ... Key return spring, 4,24
... Stopper members, 4a, 24a ... Base, 4b ... horizontal flexible parts, 4c, 24c ... vertical flexible parts, 4d, 24d
... lower limit stopper portion, 4e, 24e ... upper limit stopper portion,
5, 25: key guide, 6A: lower limit stopper, 6B: upper limit stopper, 7: subframe, 8A, 8B: strain gauge, 18C: reflector, 18D: photo sensor

Claims (2)

(57) [Claims] 1. A key support member for urging a plurality of keys upwardly by an urging means and swingably supporting the keys in a vertical direction, and a base fixed to the key support member corresponding to each of the keys. A stopper member provided with an upper limit stopper portion and a lower limit stopper portion for swinging the key at a free end portion extending in the longitudinal direction of each key via a vertical flexible portion having elasticity in the key pressing direction from each base portion. And a sensor for detecting an upward force or displacement applied to the upper limit stopper portion by the urging force of the urging means and a downward force or displacement applied to the lower limit stopper portion by pressing a key to convert the detected force or displacement into an electric signal. A tone control signal generator for an electronic musical instrument, comprising: 2. The musical tone control signal generator for an electronic musical instrument according to claim 1, wherein each of said keys is supported by said key support member so as to be swingable in a key arrangement direction. A key guide portion that is fitted to regulate the movement in the key array direction, and a horizontal flexible portion having elasticity in the key array direction, and a key array direction applied to the stopper member via the key guide portion. A musical tone control signal generator for an electronic musical instrument, comprising a sensor for detecting a force or displacement of the electronic musical instrument and converting it into an electric signal.