JP3458433B2 - 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 musical tone control signal generator for an electronic musical instrument which detects a key aftertouch to control a musical tone.

[0002]

2. Description of the Related Art Conventionally, as a musical tone control signal generator for an electronic musical instrument of this kind, as shown in, for example, Japanese Utility Model Publication No. 55-43438, the upper and lower sides and the left and right sides of a keyboard frame which rotatably supports a large number of keys. A shutter mechanism having a pair of shutter plates that interlock with swinging movements, and a pair of detectors that generate electric signals according to the swinging displacement of the keyboard frame by adjusting the irradiation light amount by the pair of shutter plates of the shutter mechanism. And a common light source for the pair of detectors, and any output in the electronic musical instrument is controlled by using the detection output from the pair of detectors as a control signal.

[0003]

However, in such a conventional musical tone control signal generator for an electronic musical instrument, since the whole keyboard frame supported by the leaf spring is oscillated, the movable part is Since the masses of the plurality of keys and the key support member are summed up, there is a problem that responsiveness is poor due to the mass, and it is difficult to control a shallow and fast vibrato with a low resonance frequency.

Further, when the keyboard frame is twisted,
There is also a problem that the detection sensitivity of the sensor that detects the force in the key pressing direction differs depending on the key arrangement direction (pitch). The present invention has been made in view of the above points, and an object thereof is to improve responsiveness and prevent detection sensitivity from changing depending on the key arrangement direction.

[0005]

In order to achieve the above object, the present invention is capable of swinging a plurality of keys vertically and horizontally.
The key support member that supports the
Supported on the base provided on the key support member via
Strikes when one of the above keys is pressed.
Equipped with a lid and a key guide that regulates the lateral movement of each key.
The stopper member and at least one of the plurality of beams
It is provided on the vertical surface of the book, and when operating the key, the key guide
Detects the magnitude of force in the key arrangement direction transmitted through the key
A musical tone control signal generator for an electronic musical instrument having a sensor .

Then, a tone control signal is generated from the above electronic musical instrument.
In a raw device, install multiple sensors on the multiple beams.
Output signal can be generated using the multiple sensors.
Both are possible.

[0007]

The musical tone control signal generator for an electronic musical instrument according to the present invention is configured as described above, so that when the keys are depressed and when the keys are depressed,
When operating the after control,
The force in the key arrangement direction applied to each beam of the member is
If the degree of fitting with the key guide is even,
Are equivalent. Therefore, the one beam near the base
The output of the sensor arranged on the vertical surface of the
By using it, it is possible to generate a control signal with good response.
It becomes possible to live.

Then, a tone control signal is generated from the above electronic musical instrument.
In a raw device, multiple beams are provided with multiple sensors,
When the output signal is formed using the multiple sensors,
The magnitude of the force signal can be doubled.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. 1 is a sectional view taken along the line AA of FIG. 2 showing a first embodiment of the present invention, FIG. 2 is a partially sectional enlarged side view seen from the direction of the arrow B in FIG. 1, and FIG. It is a perspective view showing a stopper equivalent member for explaining the operating principle.

In FIGS. 1 and 2, a white key 1A and a black key 1B (hereinafter referred to as "key 1") are integrally molded with resin in a U-shaped cross section with an open lower surface. A protrusion 1a forming a key fulcrum portion is integrally provided on the rear end portion so as to protrude downward.

Then, the recesses 1b provided on the front side of the protrusions 1a of each of the plurality of keys 1 are engaged with the front end edges of the through holes 2a formed in a row in the key arrangement direction of the keyboard frame 2 which is a key supporting member. The key 1 is movably supported in the vertical direction, and the key 1 is constantly urged in the return direction (clockwise in FIG. 2) by the key return springs 3 interposed between each key 1 and the keyboard frame 2. To do. Further, an L-shaped stopper piece 1c is vertically provided on the lower surfaces of both side walls of the key 1 near the front end portions.

On the other hand, a flexible contact rubber member 5 having a bowl-shaped bulge corresponding to each key 1 is arranged in a row on a substrate 4 fixedly provided on the lower surface of the keyboard frame 2. When the actuator 1d of the key 1 presses the contact rubber member 5 through the through hole 2b so that the contact rubber member 5 is pressed upward, the movable contact (not shown) in the contact rubber member 5 is fixed to the substrate 4 so as not to be electrically conductive. A tone is generated by connecting the contact pairs and closing the key switch.

A key guide piece is erected on the front portion of each contact rubber member 5 of the keyboard frame 2 by cutting and raising, and a sound absorbing material such as soft elastomer or foam is integrally molded on the outer peripheral portion by outsert. Then, the key guide 6 is formed, and the key guide 6 is inserted between both side walls of the key 1 to prevent lateral vibration of the key, and the stopper piece 1c on the key 1 side is provided on the lower surface of the frontmost part of the keyboard frame 2. An upper limit stopper 7 made of felt or the like with which the upper edge portion abuts is attached.

Further, a base portion 8a of the stopper member 8 is fixed along the key arrangement direction on the lower surface of the center of the keyboard frame 2 in the front-rear direction, and the longitudinal direction of the key 1 is close to both longitudinal end portions of the base portion 8a. A pair of beams 8b and 8c having elasticity in the up-down direction are integrally formed, and the stoppers 8d having a U-shaped cross section and parallel to the base 8a are integrally formed at the tips of the beams 8b and 8c. Form.

Then, a lower limit stopper 9 made of felt or the like is attached to the upper surface of the stopper portion 8d, and when the key is depressed, the key 1
The lower edge portion of the stopper piece 1c on the side is abuttable, and the rear end portion of the highly rigid sub-frame 10 is fixed to the lower surface of the base portion 8a. The sub-frame 10 and the beams 8b, 8
A predetermined gap C is formed between c and the stopper portion 8d. In addition, the base 8a of the pair of beams 8b and 8c
Strain gauges 11A and 11B are arranged on the upper surfaces of the horizontal planes, respectively, and an adding means described later for obtaining the sum of the outputs from the strain gauges 11A and 11B is provided (see FIG. 5).

Next, the operation of the embodiment constructed as described above will be described. Prior to that, the operating principle of the present invention will be described with reference to FIGS. In the stopper equivalent member 8 ′ shown in FIG. 3, the base portion 8 of the stopper member 8 is
The portions corresponding to a, the beams 8b and 8c, and the stopper portion 8d are indicated by adding "dash".

Now, a downward load F is applied to a point P between the beams 8b 'and 8c' of the stopper portion 8d 'of the stopper equivalent member 8'.
And the distances between the point P and the projected points (two fixed points) P1 and P2 on the stopper 8d 'of the strain gauges 11A and 11B are L1 and L2, respectively, the two fixed points P1 shown in FIG. The downward forces F1 and F2 acting on P2, P2 are: F1 = L2 × F / L1 + L2 F2 = L1 × F / L1 + L2 when the downward direction is positive, and the sum of the two gives the formula 1.

[0018]

[Formula 1] F1 + F2 = L2 × F / L1 + L2 + L1 × F
/ L1 + L2 = F

Further, as shown in FIG. 4B, it is assumed that a downward force F acts on a point P outside the beams 8b 'and 8c' of the stopper portion 8d ', and the distance between the two fixed points P1 and P2 is set to L
1. If the distance between the fixed point P2 and the point P is L2, the fixed point P1
An upward force F1 acts on the fixed point P2, and a downward force F2 acts on the fixed point P2. Therefore, when the downward direction is positive, F1 = −L2 × F / L1 F2 = (L1 + L2) × F / L1 is obtained, and when the sum of the two is obtained, Formula 2 is obtained.

[0020]

## EQU2 ## F1 + F2 = -L2 × F / L1 + (L1 + L
2) × F / L1 = F

From the above equations 1 and 2, even if the load F acts on any position on the stopper portion 8d ', the two fixed points P
It can be seen that the sum of the forces F1, F2 acting on 1, P2 is equal to the load F. Then, the forces F1 and F2 are applied to the two fixed points P1 and P2.
By the action of, the strain gauges 11A 'and 11B' show resistance changes in proportion to the forces F1 and F2, respectively, via the beams 8b 'and 8c'. Therefore, the strain gauge 11
The strength of the force F can be obtained from the sum of the outputs of A'and 11B '.

Here, an example of adding means for obtaining the sum Va + Vb of the outputs Va and Vb of the strain gauges 11A and 11B is shown in FIG.
Will be described. FIG. 5A shows a method for obtaining this by calculation. One of the four resistors of each of the two bridge circuits BG1 and BG2 to which the voltage V is applied to the input terminal is provided on the input terminal side. Strain gauges 11A ', 11
B ′ and the other three are fixed resistors, the outputs of the respective bridge circuits are amplified by amplifiers Amp1 and Amp2, and the outputs Va and Vb are input to the adder AD to output Va + V.
Try to find b.

In this circuit, if another fixed resistance value is selected so that the outputs of the bridge circuits BG1 and BG2 become zero when the force F does not act, the stopper portion 8d '.
Strain sensor 11 when load F acts on arbitrary point P above
The magnitude of the force F proportional thereto can be known from the sum Va + Vb of the outputs of A and 11B. In addition, in FIG. 5A, the case where two strain gauges are provided, one strain gauge and two strain gauges, respectively, is described. However, three strain gauges are used and three strain gauges are used. Even when the strain gauges are provided, the outputs of the strain gauges may be simply added.

Further, in the one shown in FIG. 5B, of the four resistors of the bridge circuit BG3 to which the voltage V is applied to the input terminal, the two resistors in the diagonal direction are strain gauges 11.
A'and 11B are used, and the other outputs are fixed resistors and each output is amplified by the amplifier AD to obtain the output Va + Vb. By doing so, the circuit can be simplified as compared with FIG.

Here, the operation of the embodiment using the above-described operation principle will be described with reference to FIGS. 1 and 2. When the key 1 is pressed by pressing the key, the upper edge of the stopper piece 1c is separated from the upper limit stopper 7, and the actuator 1d presses the contact rubber member 5 to close the key switch. Furthermore, if a downward force is applied to the key 1 by aftertouch,
The lower edge of the stopper piece 1c presses the stopper portion 8d of the stopper member 8 downward via the lower limit stopper 9. As a result, the two fixed points P1 and P2 (FIG. 1) of the stopper portion 8d are acted by the strength of the key pressing force and the force related to the key pressing position, and the beams 8b and 8c are deformed in accordance with the force. .

At this time, since the base portion 8a of the stopper member 8 is fixed to the keyboard frame 2 and has a sufficient thickness in the vertical direction, it is not deformed, and the rear end portion is attached to the base portion 8a. The fixed sub-frame 10 also hardly deforms.

Therefore, the beams 8b and 8c act as a cantilever beam whose rear end is supported by the base 8a, and the beams 8b and 8c bent downward by pressing the keys are integrally formed at their tip ends. The deformation is stopped when a part of the tip of the stopper portion 8d comes into contact with the sub-frame 10. When the beams 8b and 8c are bent, the resistance values of the strain gauges 11A and 11B change in proportion to the magnitudes of the forces F1 and F2 (see FIG. 4) acting on the beams 8b and 8c, and the adding means shown in FIG. As a result, a signal corresponding to the key pressing force at that time is input to the musical tone control circuit, and after-control is performed to change the volume, tone color, etc. according to the key pressing.

According to the first embodiment, the portion which is deformed by the after-touch is only the stopper member 8 having the base portion 8a fixed to the keyboard frame 2, so that the responsiveness is greatly improved. Further, since the key pressing force detected by the after touch does not depend on the key pressing position in the key arrangement direction, it is possible to always generate an accurate and sensitive after control signal.

In the above first embodiment, the stopper member 8 is provided with the two beams 8b and 8c, but three or more beams are provided and a strain gauge is provided for each beam. It is also possible to obtain an output signal corresponding to the key pressing force by the sum of these outputs, and the strain gauge may be provided not on the upper surface of the beam but on the lower horizontal surface. Further, as the sensor capable of detecting the magnitude of the key pressing force, in addition to the strain sensor described above, a photo sensor composed of a pair of elements arranged on the lower surface of the stopper portion 8d and the upper surface of the sub-frame 10, a magnetic sensor It is also possible to use sensors, capacitance sensors, etc.

Next, FIG. 6 is a side view showing only a main part of a second embodiment of the present invention in which a part of the first embodiment is modified, and the same parts as those in FIG. Is attached. In the second embodiment, the stopper member 8 has an inverted L-shaped cross section.
The character-shaped supporting arm 8e is integrally provided, and the upper limit stopper 7 is attached to the lower surface of the supporting arm 8e. Other configurations, operations, and effects are almost the same as those of the first embodiment.

However, in the second embodiment, since the tip end side of the stopper member 8 is lifted upward by the biasing force of the key return spring 3 via the stopper piece 1c at the time of releasing the key, the load F shown in FIG. Must be a value obtained by subtracting the above-mentioned biasing force from the actual key pressing force. That is, assuming that the urging force per key is 70 gf and the number of keys pressed is n keys, a force obtained by subtracting 70 ngf from the key pressing force acts on the stopper portion 8d.

In the first and second embodiments described above, the after-force is detected by detecting the downward force when the key is pressed, but the ones shown in FIG. 7 and FIG. FIG. 7 shows a third embodiment of the present invention in which a lateral force applied to a key after a key is detected to control a musical sound. FIG. 7 is a partial cross-sectional side view thereof, and FIG. 8 is a stopper thereof. It is a perspective view of a member. Also in this third embodiment, the same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the third embodiment, the base portion 18 of the stopper member 18 is provided on the lower surface of the keyboard frame 2 substantially at the center in the front-rear direction.
a is fixed along the key arranging direction, and a pair of beams 18b and 18c having elasticity in the left-right direction along the longitudinal direction of the key 1 are integrally formed near both longitudinal ends of the base 8a. , 18c is integrally formed with a long movable portion 18e common to the keys parallel to the base portion 18a. Then, the strain gauge 21 is attached to the vertical side surface of the beam 18c near the base portion 8a, and the movable portion 18e is provided with a key guide 18f in a row corresponding to each key, and the stopper portion is provided on the free end side of the key guide 18f. 18d is formed and a lower limit stopper 9 made of felt or the like is attached to the upper surface thereof. The other structure is the same as that of the first embodiment described above.

With the above-mentioned structure, when a horizontal force is applied to the key 1 during or after key depression, the movable portion 18e swings left and right through the key guide 18f, and the beams 18b, 18c move left and right. The resistance value of the strain gauge 21 provided near the base portion 18a of the beam 18c changes in proportion to the magnitude of the lateral force applied to the key, and a subtle sound such as a shallow and fast vibrato with good responsiveness. Can be changed.

Although the strain gauge 21 is provided only on the side surface of the beam 18c in the third embodiment, the beam 18b is provided.
It can also be provided on the side surface of the so as to double the magnitude of its output signal.
The side surfaces of b and 18c may be vertical surfaces on the inside instead of the outside.

[0036]

As described above, in the musical tone control signal generator for an electronic musical instrument according to the first aspect of the present invention, the base is key-supported.
At least one beam of the stopper member provided on the holding member
A sensor is provided, and this stopper member is provided with a key guide portion.
Since it was done, by the force in the key arrangement direction applied to the key
The displaced mass becomes smaller, and the responsive
You can get a control effect.

According to a second aspect of the present invention, there is provided a musical tone control signal generating device for an electronic musical instrument according to the first aspect.
In a raw device, multiple beams are provided with multiple sensors,
To use that multiple sensors to form the output signal
Therefore, the output signal magnitude during after control operation
Can be doubled.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 2 showing a first embodiment of the present invention.

FIG. 2 is an enlarged side view showing a part of the cross section viewed from the direction of arrow B in FIG.

FIG. 3 is a perspective view showing a stopper equivalent member for explaining the operating principle of the same.

FIG. 4 is an explanatory view showing a load acting on the stopper equivalent member and a force acting on two fixed points.

FIG. 5 is a circuit diagram for similarly obtaining the sum of outputs of two strain gauges provided corresponding to the two fixed points.

FIG. 6 is a side view showing only a main part of a second embodiment of the present invention.

FIG. 7 is an enlarged side view similar to FIG. 2, showing a third embodiment of the present invention.

FIG. 8 is a perspective view showing only the stopper member thereof.

[Explanation of symbols]

1 ... Key, 2 ... Keyboard frame, 3 ... Key return spring, 4 ... Substrate, 5 ... Contact rubber member, 6 ... Key guide, 7 ... Upper limit stopper, 8, 18 ... Stopper member, 8 '... Stopper equivalent member, 8a , 8a ', 18a ... Base, 8b, 8c, 8
b ', 8c', 18b, 18c ... beam, 8d, 8d ',
18d ... stopper part, 18f ... key guide, 11A, 11
B, 21 ... Strain gauge

Continuation of the front page (56) Bibliography Sho 61-89900 (JP, U) Rikai Hei 3-31799 (JP, U) Rikai 55-43438 (JP, U) Japanese Patent Sho 54-16405 (JP , B1) JP-B 56-2717 (JP, B2) JP-B 55-35717 (JP, B2) JP-B 55-35716 (JP, B2) JP-B 62-24318 (JP, Y1) Patent 2643577 (JP JP, B2) Patent 3319190 (JP, B2) Utility model registration 2597298 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) G10H 1/34 G10H 1/053

Claims (2)

(57) [Claims] 1. A and the key support member oscillating freely supporting a plurality of keys in the vertical and horizontal directions, a plurality of which along the key longitudinal direction
Supported on the base provided on the key support member via
Is, Bei the key guides for restricting lateral movement of one of receiving a force when depressed Carvoeiro preparative <br/> Tsu path unit and each key of said plurality of keys
The stopper member and at least one of the plurality of beams
It is provided on the vertical surface of the book and the key guide is
And a sensor capable of detecting the magnitude of the force in the key arrangement direction transmitted through the section, the musical tone control signal generating device for an electronic musical instrument. 2. A musical tone control signal for an electronic musical instrument according to claim 1.
In the generator, the plurality of beams are provided with a plurality of sensors.
And providing an output signal using the plurality of sensors.
And a musical tone control signal generator for an electronic musical instrument.