JPS5848720Y2 - Keyboard mechanism of electronic musical instruments - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a keyboard mechanism used in electronic musical instruments such as electronic organs and electronic pianos that emit sound electrically without using a mechanical vibration source.

In general, in this type of electronic musical instrument, when a given key is pressed, a switch provided corresponding to that key operates, and a sound source signal is emitted from an oscillator provided corresponding to that key. The signal is electrically processed by a filter circuit, an amplification circuit, etc., and then radiated as performance sound from a speaker.

Normally, each key in this electronic musical instrument has a pressing operation part on the tip side at the upper limit position, and when this is pressed, the pressing operation part rotates around the rotational fulcrum and the pressing operation part descends.
Along with this, when a switch is turned on using an actuator attached to a predetermined part of the key, for example, at the rear end, and when the suppressing operation is released by releasing the finger from the pressing operation part, the force of the weight or spring is used to turn on the switch. It is designed so that it can be rotated back to the state shown in FIG.

In the keyboards of conventional electronic musical instruments, the force applied to the keys is the force of weights or springs, so the force applied to the fingers when pressing the keys is approximately constant or increases slightly gradually.

Incidentally, an acoustic piano (hereinafter simply referred to as a piano) has been known as a natural musical instrument, and a piano has strings, and the strings are mechanically struck to produce sound.

That is, by pressing a key, a string-striking mechanism called a piano action is operated, and the hammer is caused to fly towards the strings and strike the strings.

Then, in order to prevent the hammer from striking the string twice or remaining in contact with the string, causing so-called chatter, after the hammer has rotated a predetermined angle toward the string,
The jack used to push up and rotate the hammer is separated from the hammer butt to which the hammer is attached (
(referred to as escape or left-off), the hammer then uses the imparted kinetic energy to fly towards the strings and strike them.

Therefore, on a piano keyboard, the force applied to the fingers when pressing a key becomes somewhat lighter at the same time as the hammer begins to fly with its own kinetic energy, that is, as soon as the jack leaves the hammer butt, You can feel when you strike a string as a change in the force applied to your fingers.

This feeling, or key touch, is considered desirable due to the fact that we have been familiar with the piano for a long time, and the piano is a relatively high-class keyboard instrument, and in fact, it is easy to play. .

However, as mentioned above, with the keyboards of conventional electronic musical instruments, the force applied to the fingers when pressed is approximately constant or increases slightly gradually, so when a sound is produced, it is felt as a change in the force applied to the fingers. Therefore, it cannot be said that it provides a desirable key touch.

On the other hand, the rotation angle of the key, that is, the amount of pressure required to turn the switch ON, must be appropriate and uniform for each key, but in order to do this, the relative position of the actuator and switch must be appropriate. It also needs to be uniform.

By the way, when making the relative positions of the actuator and switch uniform and appropriate, the longer the stroke (travel) of the actuator when a key is pressed, the higher the accuracy. In some cases, the actuator is attached to the key, so the stroke of the actuator is limited, and if the overall length of the key is increased in order to lengthen the stroke of the actuator, the overall size of the instrument becomes undesirable.

This idea was made in view of the above circumstances, and it is possible to obtain the same key touch as on a piano, and also to use an electronic device that allows the relative position of the actuator and the switch operated by the actuator to be accurately and easily set. The purpose is to provide a keyboard mechanism for a musical instrument, and its features include a retaining piece having a valley and a peak that are smoothly continuous with each other at the upper rear side of the pivot point of the key. A weight plate is rotatably provided above the engagement piece, the weight plate having a protrusion protruding near the center of rotation that slides frictionally against the troughs and crests;
When the protrusion reaches the upper end of the peak, the frictional force disappears and the force required to press the key becomes lighter, and an actuator for operating the switch is attached to at least one end of the weight plate. The point is that the stroke of the actuator is increased.

An embodiment of this invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a key frame, which is arranged in large numbers at predetermined locations on the front side of the instrument body (not shown).On the upper surface of approximately half of the tip side (left side in Figure 1) of this keyboard frame 1, there is an iron plate or A frame 2 formed by bending a metal plate such as an aluminum plate is mounted and fixed.

As shown in the figure, this frame 2 has a stopper part 2a formed by bending its tip into a substantially U-shape and pasting a cushioning material such as felt on the lower surface of the upper end piece, and a stopper part 2a. Slightly behind 2a (right side in Figure 1)
a guide portion 2b formed by bending the guide portion 2b upward;
It consists of a fulcrum portion 2C formed by bending upward at the rear end, that is, approximately at the center of the keyboard frame 1.

The frame 2 is rotatably supported on the frame 2 with its fulcrum 2C as a rotation fulcrum, and the stopper part 2a
A key 3 is provided which is prevented from rotating clockwise in the figure.

That is, the key 3 has a hollow, substantially rectangular pressing operation part 3a.
and an arm 3b made of a metal plate whose tip is inserted and fixed into the pressing operation part 3a, and a recess 3C is formed in the approximate center of the lower end of the arm 3b in the longitudinal direction. , these four parts 3C are rotatably engaged with the fulcrum part 2C, and the front lower end of the pressing operation part 3a is bent forward into an L-shape to form a locking part 3d.
is formed, and by engaging this locking portion 3d with the stopper portion 2a, clockwise rotation is prevented. By engaging this guide part 2
b is designed to prevent the key 3 from swinging laterally.

On the other hand, a rib 3e extending in the longitudinal direction is formed protruding from one side surface of the arm 3b, and a trough portion 4a and a peak portion 4b that are smoothly continuous with each other are formed on the upper end surface of the rear end portion of the rib 3e. A retaining piece 4 formed in is attached.

The arm 3 is attached to the rear end of the keyboard frame 1.
A support plate 5 is provided upright so as to be located on the side of the location where the retaining piece 4 of b is attached, and a weight plate 6 that engages with the engagement piece 4 is attached to the support plate 5 with a pin. It is rotatably attached at 7.

In other words, the weight plate 6 is slightly bent as shown in the figure.
The weight of the portion on the rear end side (right side in the figure) of the pin 7 is heavier than the portion on the front end side, and normally rotates clockwise in the figure, and the weight plate 6 A protrusion 6a that frictionally slides against the troughs 4a and peaks 4b of the engaging piece 4 is directed diagonally downward at the lower end of the pin 7, which is the rotation center of the pin 7. It is integrally formed in a protruding manner.

When the key 3 is rotated by pressing down its pressing operation part 3a, the weight plate 6 is pushed up and rotated via the engagement piece 4 and the protrusion 6a, and along with this, the protrusion 6a
is configured to frictionally slide from the valley portion 4a to the peak portion 4b of the engaging piece 4, and the frictional force generated at this time acts as a resistance force against the rotational movement of the key 3.

Furthermore, an actuator 8 is attached to the rear end surface of the weight plate 6, and a key switch 10 is provided corresponding to the actuator 8, which is attached to an appropriate bracket 9 and connected to a printed circuit board (not shown). When the weight plate 6 rotates as the key 3 is pressed and rotated, the actuator 8 pushes the movable contact 10a of the key switch 10 to turn the key switch 10 ON. has been done.

Furthermore, a stopper piece 11 is provided at the lower end of the arm 3b at a location slightly closer to the rear end than the recess 3C, which abuts the tip of the weight plate 6 and prevents it from rotating beyond the limit position. Further, a spring 12 for rotating the key 3 clockwise in the figure is stretched between the key frame 1 and the lower rear end of the arm 3b.

In addition, 13 in FIG. 1 is a cushioning material attached to the upper surface of the tip part of the key frame 1, with which the lower end surface is brought into contact when the pressing operation part 3a is pressed down.

Next, the operation of the keyboard mechanism having the above configuration will be explained.

Figure 1 shows the state where no pressing operation is performed, and the key 3
is urged to rotate clockwise about the fulcrum 2C by the tension of a spring 12 provided at its rear end,
A locking portion 3d formed on the pressing operation portion 3a comes into contact with the stopper portion 2a, thereby locking the pressing operation portion 3a at the upper limit position.

In this state, the retaining piece 4 is in a slightly lowered position, and therefore, the weight plate 6 is locked in a predetermined position by its protrusion 6a engaging with the valley portion 4a of the engaging piece 4.

When the push operation part 3a is pressed down from this state and the key 3 is rotated counterclockwise in the figure, the engagement piece 4 is integrated with the rear end of the key 3, as shown in FIGS. 2 and 3. This causes the weight plate 6 to be rotated counterclockwise in the figure by pushing up the weight plate 6 via the protrusion 6a.

In this case, the protrusion 6a frictionally slides from the trough 4a to the ridge 4b of the engagement piece 4 as shown in FIGS. 2 and 3, and as a result, in addition to the moment caused by the spring 12 and the weight plate The frictional force caused by the frictional sliding of the protrusion 6a acts as a resistance force against rotating the key 3, giving the key a so-called heavy touch.

Push down the push operation part 3a further to move the key 3 to the limit position.
That is, when the lower end of the pressing operation part 3a rotates until it comes into contact with the buffer material 13, the weight frame 6 further rotates counterclockwise in the same manner as in the above case.

Then, the protrusion 6a frictionally slides toward the ridge 4b of the engagement piece 4, and when it finally reaches the upper end of the ridge 4b as shown in FIGS. 4 and 5, it engages with the protrusion 6a. The frictional force between the key and the mating piece 4 disappears instantaneously, and as a result, the touch of the key instantly becomes lighter.

Then, when the protrusion 6a reaches the upper end of the crest 4b and the frictional force disappears, the actuator 8 simultaneously or almost simultaneously pushes the movable contact 10a of the key switch 10 to release the key switch 1.
0 turns on the key switch 10 by pressing the movable touch 10a, and as a result, a performance sound of a pitch corresponding to the pressed key 3 is emitted from a speaker (not shown).

Therefore, the key touch of the above-mentioned keyboard mechanism instantly changes from a certain heavy state to a light state, and at the same time or almost simultaneously the performance sound is emitted, so it is very similar to the key touch of a piano with the above-mentioned action mechanism. becomes.

On the other hand, in the keyboard mechanism configured as described above, since the protrusion 6a is provided protruding near the rotation center of the weight plate 6, when the weight plate 6 is pushed up and rotated via the protrusion 6a, the weight is The amount of movement of the rear end of the plate 6, that is, the amount of movement of the actuator 8, is made larger than the amount of movement of each part of the key 3. Therefore, the ratio between the amount by which the pressing operation part 3a is pressed down and the amount of movement of the actuator 8 is large; The rotation angle of the key 3, that is, the amount of pressure required to turn on the multiple lock switch 10, can be easily set uniformly and appropriately for each key.

Note that when the protrusion 6a reaches the upper end of the crest 4b and the frictional force disappears, the tip of the weight plate 6 comes into contact with the stopper piece 11 fixed to the arm 3b, thereby preventing its rotation in the counterclockwise direction. movement is prevented.

In the above embodiment, one actuator 8 is attached to the rear end of the weight plate 6, and one key switch 10 is provided corresponding to this actuator 8, but this invention is not limited to the above embodiment. A plurality of actuators of different lengths are arranged in parallel at the rear end of the 6, or a plurality of stages of actuators with different operating points are provided, and a plurality of key switches are provided corresponding to each actuator or operating point. Good too.

In this case, since the amount of movement of the rear end of the weight plate 6, that is, the stroke of the actuator is large, the contact time difference of each key switch can be set with high accuracy.

Further, in the above embodiment, the spring 12 is provided to urge the key 3 to turn in the clockwise direction, but this invention is not limited to the above structure. There may be.

As explained above, according to the keyboard mechanism according to this invention,
A retaining piece having troughs and peaks that are smoothly continuous with each other is attached to a predetermined location on the rear end side of the key's rotational fulcrum, and as the key rotates, the protrusion integrally protrudes above the key. A weight plate that frictionally slides from the trough to the peak is provided, and when the key is pressed, the friction force generated between the protrusion and the retaining piece is used as a resistance force against the key pressing operation, and the protrusion When the top of the crest is reached, the frictional force disappears and the pressing operation on the keys becomes lighter, so it is similar to when the pressing operation on the keys becomes lighter just before the strings are struck on a normal piano, and it is different from a normal piano. You can get a similar key touch.

In addition, a protrusion is provided protruding near the center of rotation of the weight plate, and an actuator for turning on the key switch is attached to at least one end of the weight plate, so that the actuator moves when the key is pressed. The amount of pressure required to turn on the key switch is large, and therefore it is easy to make the amount of key press required to turn on the key switch uniform and appropriate for each key.

[Brief explanation of the drawing]

Fig. 1 is a side view showing one embodiment of this invention, Figs. 2 to 5 show the operation, Fig. 2 is a side view of the main part with the key turned approximately half way, and Fig. 3 The figure is III in Figure 2.
4 is a side view of the main part with the key rotated to the limit position, and FIG. 5 is a detailed view of the V section in FIG. 4. 2C...Fully point, 3...Key, 3C...
...Concavity, 4...Engagement piece, 4a...
・Trough, 4b... Peak, 6... Weight plate,
6a... Protrusion, 8... Actuator, 10... Key switch.

Claims (1)

[Scope of utility model registration request] A retaining piece having valleys and peaks that are smoothly continuous with each other is provided on the rear upper surface of the rotational fulcrum of the key, and a protrusion that frictionally slides against the valleys and peaks of the retaining piece is provided. A weight plate formed near the center of rotation and having an actuator attached to at least one end for operating a switch is rotatably provided above the retaining piece, and is rotated by pressing the key. At the same time, by pushing up and rotating the weight plate through the retaining piece and the protrusion, the protrusion frictionally slides from the trough to the crest of the engagement piece, and the crest of the engagement piece is moved. A keyboard mechanism for an electronic musical instrument, characterized in that the actuator operates the switch as the actuator reaches the upper end.