JPS5812235Y2 - Keyboard device for electronic musical instruments - Google Patents

Description

[Detailed explanation of the invention] This invention reduces the number of parts and simplifies the assembly process by making the movable contact member of the key switch have a common continuous integral structure for multiple keys. The present invention relates to a keyboard device for an electronic musical instrument, and more particularly to a keyboard device for an electronic musical instrument that facilitates the arrangement of movable contact members and prevents deformation and warpage of a printed circuit board on which fixed contacts are formed.

In conventional keyboard devices for electronic musical instruments, key switches were provided separately for each key, which resulted in a large number of parts and required many steps for assembly, making the device complicated, large, and expensive. had.

In particular, mechanical type key switches using metal contacts are 1
The number of parts is very large, making it difficult to miniaturize, and the contacts tend to deteriorate, and precious metals such as gold and silver are used to prevent this deterioration, resulting in high costs.They also tend to cause chattering when making contact. It had drawbacks.

Furthermore, since the printed circuit board on which the fixed contacts are formed is directly fixed to the keyboard frame, it may become deformed or warped due to temperature changes.

This invention aims to eliminate the above-mentioned conventional drawbacks and to provide a keyboard device having a key switch suitable for application to a key switch circuit of an electronic musical instrument using digital technology, which will be described later.

Hereinafter, this invention will be explained in detail with reference to an embodiment of the accompanying drawings.

Figure 1 shows the basic configuration of a key switch circuit for an electronic musical instrument using digital technology that has been proposed in recent years (for example, Japanese Patent Publication No. 50-33407).
The case of an electronic musical instrument with four keys (C5 to F2) is shown as an example.

This key switch circuit 1 detects the pressed state of each weight by scanning with a note counter 4.

The note counter 3 is composed of, for example, a decimal ring counter, and is driven in steps by clock pulses from the clock pulse source 2, and signals IN1jp are sequentially outputted from the output terminals M1 to M12 at the timing of the clock pulses.

The octave counter 4 is driven in steps by the output signal from the output terminal M12 of the last bit of the note counter 3, and signals (-1) are sequentially output from the output terminals N1 to N4.

Key switches s1 to S44 correspond to each of the weights C6 to F2.

Movable contacts P1 to P44 of this key switch 81 to S44
The notes are connected in common by common connection lines t1 to t12 for each note name, and the outputs of the note counter 3 are respectively applied to the common connection lines t1 to t1°.

In addition, fixed contacts Q1 to Q44 of key switches S1 to S44
It's a notebook C6-C and a C3-C! 0IC3 to F2 are connected in common by common connection lines L1 to L4, respectively, and the signals on these common connection lines L1 to L4 are connected to two-person AND circuits A1 to A1 to which each output of the octave counter 4 described above is added.
It is added to the other input terminal of A4.

Then, the outputs of the AND circuits A1 to A4 are sent via the OR circuit 5 to If! υ is released.

According to the key switch circuit 1 having such a configuration, although detailed explanation is omitted, all the key switches 81 to S44 are sequentially and periodically scanned by the note counter 3 and the octave counter 4, and the output terminal of the OR circuit 5 is 6 key operation/
A binary signal representing the inactive state is continuously output in serial form.

Therefore, in the time slot corresponding to the 6 keys, the signal It 1
The pressed state of the six keys can be determined based on whether or not jj is occurring.

FIG. 2 shows an embodiment of the keyboard device according to this invention in a side sectional view.

A fulcrum groove 12 is cut in the upper surface of the rear end of the key 11 in the width direction thereof, and an upper edge 14a of a hole 14 formed in a rear end rising portion 13a of the keyboard frame 13 fits into this fulcrum groove 12. and forms a fulcrum for the rotation of the key 110.

A spring 16 is fitted between the base 15 and the inner surface of the key 11 in the spring holder provided in front of the rear end rising portion 13a of the key frame 13, and this spring 16 uses the fulcrum groove 12 of the key 11 as a fulcrum. A force is applied to the key 11 to rotate it upward.

An L-shaped hook portion 17 projects downward from the front portion of the key 11, and its horizontal portion 17a comes into contact with an upper limit stopper cushioning material 18 provided on the lower surface of the front end of the keyboard frame 13. This cushioning material 18 restricts the upward movement of the key 11 by the spring 16.

Board supports 21a and 21 are provided on the bottom surface of the keyboard frame 13.
A printed circuit board 22 whose front end and rear end are each held by b is disposed.

Here, the front end and the rear end of the printed circuit board 22 are held at two locations by the board supports 21a and 21b, respectively.
The reason for this is to prevent deformation and warping of the board 22.

In other words, in the past, the printed circuit board 22 was directly connected to the keyboard frame 1.
Since the substrate 22 was fixed at 3, the substrate 22 was deformed and warped when the substrate 22 expanded due to temperature changes or the like.

However, as mentioned above, the printed circuit board 22 is
If the printed circuit board 22 is held through the board supports 21a and 21b, the printed circuit board 22 can be extended.

The printed circuit board 22 is absorbed by the fitting portion with the printed circuit board 21b, and even if it tries to deform, the insects are removed and the printed circuit board 22 does not deform or warp.

Note that the printed circuit board 22 does not necessarily need to be held at two locations as described above, and may be held at one location or at several locations, for example, two or more locations.

A key switch 23 is formed on this printed circuit board 22.

The key switch 23 includes a fixed contact 30 formed on the printed circuit board 22 and a holding portion 27a protruding from the keyboard frame 13, as shown in detail later in FIG.

27b, the movable contact part 29 is disposed on the fixed contact 30, and when the key 11 is pressed, the actuator 19 disposed on the key 11 passes through the hole 20 bored in the keyboard frame 13 and activates the key switch. The movable contact member 29 of 23 is brought into contact with the key switch 23 to drive the key switch 23.

At this point, the key 11 is guided by a key guide 24 that contacts its inner surface, and the downward movement of the key 11 is regulated by a cushioning material 25 serving as a lower limit stopper.

By the way, the holding part 2 that holds the movable contact member 29 mentioned above
7a and 27b serve to facilitate the arrangement of the movable contact member 29, and to prevent the movable contact member 29 from spreading laterally when the movable contact member 29 is suppressed by pressing the key, thereby ensuring the operation of the key switch 23. It has the effect of making it.

Note that the holding parts 27a and 27b are attached to the keyboard frame 13.
0 It can be easily formed by cutting and raising the part.

FIG. 3 shows a printed circuit board 22 on which a key switch 23 is installed.
FIG. 2 is a perspective view showing the main parts of the

The key switch 23 has a fixed contact 30 formed on the upper surface of the substrate 22, and is arranged on the fixed contact 30 and has keys 06 to F2.
The movable contact members 2 are continuously arranged over the entire width in the arrangement direction.
Consists of 9.

The movable contact member 29 includes a movable portion 2.9a and a movable portion 2.9a.
Fixing parts 29b, 29c and 1 parallel to a and arranged on both sides
It includes flexible support parts 29 d and 29 e that connect the movable part 29 a and the fixed parts 29 b and 29 c, and are arranged continuously over the entire width in the arrangement direction of the keys C6 to F2.

Further, movable contact portions 26 made of conductive rubber, for example, are attached to the bottom surface of the movable portion 29a, divided into octaves.

Such a movable contact member 29 is located at a position where the movable portion 29a is pressed by the downward movement of the actuator 190 of the key 11, and such that the movable contact on the bottom surface of the movable portion 29a is slightly separated from the top surface of the printed circuit board 22 when not pressed. will be placed in

A fixed contact 30 is formed on the upper surface of the printed circuit board 22 at a position facing the actuator 19 of each weight 11 of C6 to F2.

This fixed contact 30 consists of comb-shaped electrodes 30a and 30b arranged close to each other, one electrode 30a is commonly connected for each octave, and the other electrode 30b is connected for each note via a diode 28. They are commonly connected.

The above is an example of the configuration of a keyboard device for an electronic musical instrument according to this invention. According to this configuration, when the key 11 is not pressed down in the state shown in FIG. The actuator 19 is in a horizontal state due to the member 18, and the actuator 19 is in a state separated from the movable portion 29a of the movable contact member 29.

Therefore, the movable contact portion 26 and the fixed contact 30 are separated from each other, and the key switch 23 is in an open state.

When the key 11 is pressed down, the key 11 rotates counterclockwise using the bottom of the fulcrum groove 12 as a fulcrum, and the actuator 19 moves the movable part 29a of the movable contact member 29 in response to the rotation of the key 11.
Press.

The support parts 29d and 29e are bent by this pressing force, and the movable part 29a is moved downward, so that the movable contact 26 at the bottom of the lower movable part 29a comes into contact with the fixed contact 30, and the electrode 30a of the contact 30 is moved downward.
and 30b.

When the key 11 is pressed further, the movable portion 29a has a hollow structure and collapses in response to the pressing force, absorbing and relaxing the pressing force of the key 11.

Therefore, due to the action of this movable part 29a, the key switch 11
The excessive pressing force applied to the keys can be buffered, and the keys can be given a slight extra stroke, or "struggle", necessary for playing.

Therefore, key operations during performance can be made smooth and soft.

When the pressing blade of the key 11 is released, the key 11 is released by the spring 1.
60 It rotates clockwise due to the repulsive force and returns to the horizontal position shown in FIG.

At the same time, the actuator 19 moves upward, and along with this, the movable part 29a1 of the movable contact member 29, the support parts 29e and 29d
will also return to its original state.

As the movable part 29a moves upward, the movable contact part 26 contacts the fixed contact 3.
electrodes 30a and 30b of the fixed contact 30, spaced apart from o;
will be released.

Therefore, if the keyboard device according to this invention described above is applied to the key switch circuit shown in Fig. 1, even if multiple keys are pressed within the same octave or multiple keys are pressed within the same note, each key will be Since the operating and non-operating states of the weights are detected in a time-sharing manner, there is no problem in identifying the pressed state of each weight. Therefore, it is possible to reduce the number of parts and simplify the assembly process.

Furthermore, according to this invention, the movable contact member can be easily arranged, the key switch can operate reliably, and the entire keyboard device can be made simple and compact. It has good properties and has great effects such as preventing chattering from insects.

In the above embodiment, the movable contact member 29 is formed of a movable part and a fixed part made of an insulating elastic member, and conductive rubber is attached to the bottom surface of the movable part. As shown in the figure, a movable part 29a' and fixed parts 29b', 29c
' and support part 29a'.

The entire part 29e is made of conductive rubber, and an insulating member 33 is arranged on the bottom surface of the fixed part 29c' on one electrode 30b' side of the fixed contact 30' connected to the diode 28, and the movable contact 29
' may be insulated by the insulating material 34 for each octave, or may be cut for each octave, and it will be obvious that the same effect as described above can be obtained even in this case.

In this case, only the fixed contact 30' is connected to the movable part 29a.
Since the fixed contact 30' can be disposed on the lower surface of the fixed contact 30', the structure of the fixed contact 30' can be further simplified.

That is, the electrodes 3Qa' and 3Qb' can be made into a simplified shape as shown in FIG.

Further, in the above description, the electrodes of the fixed contacts were formed using the conductive pattern 7, but as shown in FIG. 5, through holes 31a and 31b are formed in the printed circuit board 22.

Metal wires 32a and 32b may be inserted into 31c and 31d.

Furthermore, in the above description, in order to apply it to the key switch circuit shown in Fig. 1, the conductive rubber constituting the movable contact part is divided into octaves, but it is also possible to connect and divide it according to the configuration of the electric key switch circuit. , and various other modifications and changes are possible.

In the above-described embodiment, the printed circuit board on which the key switch and the like are arranged and the board holder are disposed below the keyboard frame, but they may be disposed above the keyboard frame.

In this case, it goes without saying that the holder for holding the movable contact member is disposed above the keyboard frame so as to penetrate through the printed circuit board.

Even with such a configuration, effects similar to those of the specifically mentioned embodiment can be obtained.

[Brief Description of the Drawings] Fig. 1 is a basic configuration diagram of a key switch circuit used in this invention, Fig. 2 is a cross-sectional side view showing an embodiment of a keyboard device for an electronic musical instrument of this invention, and Fig. 3 4 is an enlarged partial cross-sectional perspective view showing the main parts of the same embodiment, FIG. 4 is an enlarged partial cross-sectional perspective view showing the main parts of another embodiment, and FIG. 5 is a fixed contact portion of still another embodiment. FIG. 3 is an enlarged perspective view. 1...Key switch circuit, 21a, 21b...
... Board holding part, 23 ... Key switch, 27
a-27b...Movable contact holder, 29...
...Movable contact member, 30...Fixed contact.

Claims (1)

[Scope of utility model registration request] A keyboard frame on which a plurality of keys are mounted, a printed circuit board on which fixed contacts corresponding to the plurality of keys are formed, and at least one side edge of the printed circuit board is held and the printed circuit board is attached to the keyboard frame. A substrate holder fixed in parallel, a movable contact member having an integral structure connected to each weight, having a movable part having a movable contact and a fixed part connected to the movable part, and formed on the frame. and a holding section for holding the movable node member placed on the printed circuit board.