JPS599696A - Keyboard for electronic musical instrument - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a keyboard switch for an electronic musical instrument that provides a good key touch feeling and is easy to assemble.

Used in electronic musical instruments such as Yuko organs, each key's drive MtJJ
Detect! ! I! A panel switch is equipped with a plurality of movable contact plates arranged in parallel corresponding to each terminal, and a plurality of fixed contacts arranged in correspondence with these, and is arranged below the key. There are known devices in which the switch section is made into a unit as shown in FIG. 1, and in which the switch circuit shown in FIG. 2 is processed on a printed circuit board. That is, the keyboard switch shown in FIG.
Between the outer ends of several branch pieces 1a integrally extended to l111JII, both normal and reverse scale points 2 and 3, which are parallel to each other in a half line with a slight distance between them, are fixed. The base ends of a large number of movable contact pieces 4 are embedded at intervals, and the tips thereof are inserted between the fixed contacts 2 and 3 to connect one of the fixed contacts 2.
The actuator 5 is fixed with an acid layer on both upper and lower surfaces near the tips of these aI movable contacts 4 to form a unit. However, although such unitization makes it possible to extremely efficiently and simplify the assembly work of the keyboard switch, the contact pressure between the movable contact piece 4 and the fixed contact 3 will increase if the ridge operation is continued even after the switch is closed. Not only does this accelerate the wear of both of them and has a negative effect on the key touch feeling, but if the contact pressure is high, the solid case contact 3 may bend over many years of use.
This had the disadvantage that the operating point of the switch, in other words, the position of sound generation, was disturbed.

On the other hand, the keyboard switch shown in FIG. 2 has a substantially bowl-shaped key switch cover 9 made of soft elastic material placed on a printed circuit board 10 on which a switch circuit is formed.
A conductor 12 is provided inside the cover 9, and a pair of ground electrodes are provided corresponding to the conductor 12. ? i13 to printed circuit board 10
When the cover 9 is pressed and deformed by the actuator 14 of the key 11 when the key is pressed, the conductor 12 is brought into contact with the copper foil 13.

However, since the key switch cover 9 is also conveniently used in this type of VC, it has the disadvantage that the key touch feeling is deteriorated due to the suppression after the switch is closed, similar to the conventional structure described above.

This invention was made in view of the above-mentioned drawbacks of the conventional art, and consists of a pair of upper and lower printed circuit boards each having a plurality of fixed contacts on at least one side, and a plurality of movable contact plates disposed between these printed circuit boards. One end of the movable contact plate is held in common by a metal holder to form a unit, and the free end of each movable contact plate is compressed and deformed by the key's actuator. This provides a good key touch feeling, improves assembly workability, and improves dustproof performance.
! The present invention provides a keyboard switch for an electronic display device that improves the performance.

Hereinafter, this invention will be described in detail based on embodiments shown in the drawings.

FIG. 3 is a partially cutaway side view of a keyboard section equipped with a keyboard switch according to the present invention, and FIG. 4 is an exploded perspective view showing the switch with some parts omitted. In these figures, 30 is a key made of synthetic wood, and the key 30 is formed by hollowing out the back side, so that the bent shape of the key 30 is approximately U-shaped. A retaining opening 33 is formed on the lower surface of the rear end and constitutes a pivot point for the key 30 by being engaged with the front edge of a push-through hole 32 formed in the keyboard frame 31. On the other hand, a substantially hook-shaped stopper 34 is integrally provided on the upper part of the front end of the key 30, and a lower end 34a extending toward the rear of the stopper 34 is connected to the M board frame 31.
The key 30 is fitted into a through hole 35 provided in the front face 31a of the key 30 so as to be movable downward, thereby changing the vertical rotation angle of the key 30 to fl, f171J. At the rear of the front B piston buckle 34, there is a key guide 36 whose lower end engages in a hole 38 formed on the upper surface of the keyboard frame 31 to restrict the left and right rotation of the key 30, and a keyboard switch 45 which will be described later. An actuator 3775 is provided integrally with the inner bottom surface of the key 30 to control opening/closing.The base of the actuator 37 is provided with a constant clockwise reciprocity on the rear surface of the actuator 37. A locking pin 40 is provided for locking one end of the lowering barb 39, the lower end of which passes through a through hole 41 provided on the upper surface of the keyboard frame 31 (below the frame 31). 5. The return spring 3
9d, it is formed by punching out a metal plate of an appropriate thickness, and the other end is secured by a spring locking part 43 provided on one surface of the keyboard frame 31, so that the seat h is secured as shown in the figure.
Situation 3 due to the reaction force generated by this buckling deformation.
At the same time, the engagement recess 33 of the key 30 is pressed against the front edge of the push-through hole 32. Therefore, the key 30 is normally held horizontally by the top surface of the tip of the stopper 34 coming into contact with the upper edge of the through hole 35 .

The keyboard switch 45 is disposed approximately in the center of the lower surface of the keyboard frame 31 so as to extend in common with the keys 3o of JL and TL, and is connected to a pair of upper and lower printed circuit boards 50.
, 51, a pair of holes X'52, 53 that hold both short side ends of these printed circuit boards 50.51, and a movable contact plate 7J consisting of a plurality of movable contact plates 54 interposed between the printed circuit boards 50.51. % Nf7 nt4 It is constituted by a fixed contact group consisting of a plurality of fixed contacts 55, 56 provided on opposite sides 101 of the lint board 50, 51, with 11 sides apart.

As shown in FIG. 5, the pair of printed circuit boards 50 and 51 are formed by dividing a long and thin printed circuit board 6o into a perforated hole 61 drilled in the center thereof (v). As a result, prior to this cutting, both boards 50 and 51 are electrically and mechanically connected by several jumper lead wires 62. Attachment portions 63a and 63b for connecting connectors are provided at the rear edge of each printed circuit board 50, 51 and at the end opposite to the cutting side.
are provided integrally with each other, and have a plurality of pin insertion holes 64. A sixth pin insertion hole 64 is provided in these pin insertion holes 64.
As shown in the figure, a harmful electrical film 65 is applied and a connector 67
Each pin 68 of is inserted. Upper printed circuit board 5
A plurality of fixed contacts 55 provided on the board 50 are arranged in parallel in the longitudinal direction of the board 50 corresponding to the valley keys 30, and directly below them are a pair of front and rear spacers 57a+57b as shown in FIG.
A film 58 made of polynisdel, etc., whose front and rear ends are fixed downwardly, is disposed at a slight interval. and,
A plurality of electrodes TO are provided on the upper surface of this film 58 by a printing method, corresponding to the Tanigo rectangular contacts 55.

Fixed contacts 5 similarly provided on the lower printed circuit board 51
6 are also arranged in parallel corresponding to each key 30 to face each of the 44 fixing points 55 of the upper printed circuit board 50,
Above it, a frame 71 is mounted with a pair of spacers 72a and 72b so as to maintain a small distance from the fixed contact 56.
It is arranged through. A plurality of electrodes 73 are printed on the lower surface of the film 71, corresponding to each solid contact 56.

The pair of holders 52 and 53 are arranged at the rear, and the holder 52 is formed integrally with the M number of movable contact plates 54 during molding, thereby cantilever-supporting these contact plates 54. The printed circuit board s is attached to the upper and lower ends of the front curved side.
Fitting grooves 76 and 77, which are approximately equal in thickness to the plate thicknesses o and si, are formed in parallel over the entire length of the holder 52. Unfortunately, a screw mounting g7'8 for fixing the holder is integrally protruded from the inner end of the front [m side] of the holder 52. On the other hand, the holder 53 on the jJIJ side has the same length as the rear holder 52, and has a plurality of rectangular openings 1-1 corresponding to the valley fi30 in the longitudinal direction.
A pair of fitting grooves ao and ai corresponding to the lower fitting grooves 76 and r7 of the rear side holder 52 are formed on the back +u1, and a pair of fitting grooves ao and ai are formed in the back side holder 52. A screw attachment portion 82 that engages with the attachment portion 78 is integrally provided in a protruding manner. Therefore, the upper pair of printed circuit boards 50.
51, the front plate end of A is the low matching groove 76 of the valley holder 52, 53.
゜77.80.81, the setscrews 83 are held parallel to each other with a predetermined distance apart, and are screwed into the front yt screw mounting portions 78, 82 (see Fig. 3).
The printed circuit board 50.51 and the holder 52.53 are integrally connected, and the back surface of the keyboard frame 31 is placed at a predetermined position 1.
It is fixed at a.

m Hr2 A plurality of i=J movable contact plates 54 are arranged in parallel in the longitudinal direction of the boulder 52 corresponding to the keys 3o, and the base 54afll! I extends horizontally toward the front, and the free end Q1i 54 b is bent at an appropriate angle to pass through each turn 1'' portion 79 of the front side holder 53, and its protruding end connects to the actuator of the valley 30. Normally pressed against the bottom surface of 37 J
There are L and -C. Further, in the connecting portion between the base 54a and the free end 54b of the valley drive contact plate 54, there are pressing pieces 84 made of conductive rubber or the like corresponding to the fixed contacts 55 and 56 of each printed circuit board 52 and 53. difference! Then, the film 5B (see FIG. 6) of the upper printed circuit board 50 is pressed from the -T direction by -i1]J. Therefore, in this state,
Each conductor 70 provided on the surface of the film 58 is brought into contact with the contact 55 to form a normally closed switch.

When the key 30 is pressed in the above 44 configuration, the key 30 rotates downward in the counterclockwise direction using the front edge of the insertion hole 33 as a rotation fulcrum, so that the actuator 3
The movable contact plate 5 corresponding to the key 3o is also lowered together with T.
Push the free end 54b of 4].

As a result, the suppressing piece 84 separates from the top 11 (IJ film 58 and separates the conductor 70 from the solid contact 55, causing the ridge 3
0 is pressed down at the lowest Mt/(When 1. The lower opening J1 of the pressing piece 84 presses the lower film 71, and compared to the corresponding mechanism 13o provided on the back surface of the film 71 at J'L, [~
The conductor 73 is brought into contact with the fixed contact 56. That is, the fixed contacts 56, - and the conductor 73 constitute a normally open switch, and as mentioned above, when the key 30 is pressed i! l! It is configured to have two IL paths that, when closed in response to an operation, electrically generate a musical tone corresponding to the M30. in this case,! Q! By measuring the difference in opening/closing time between the normally closed switch and the normally open switch described in I above, keystroke speed, touch response, etc. can be detected.

In this way, such a configuration can be used as the ridged switch 45.
According to Plate 5, a pair of printed boards are provided with fixed and redundant contacts 55 and 56 on the broadside, each corresponding in size to the valley key 3o.
0, 51, a pair of holders 52, 53 that hold these printed circuit boards sj, s1, and a plurality of keys 52, 53 that are integrally provided in the holder 52 and correspond to each key 30! Since the contact plate 54 and the IJ are integrated into a unit, installation to the keyboard 31 is easy.
? With just one piece, you can save a lot of time wasting time on assembly work. ) 1 trap, set the excitation contact plate 54 to 4'S ij
, rL, its free 11 parts part 541] to actuator 3
1-C 坤゛] Jσ is configured so that a good key touch feeling is achieved by 1.4, and the fixed contacts 55 and 56
are respectively reflected on film 58 and 71, and the movable contacts &
54 pcs. 1 - Pair of printed circuit boards 50 and 51 for protection.
I'm going to get along with you, and I'm going to be a young rice 7.・・It is large enough to remove dust, etc.

7th L, J+-, J, This older brother t) A cross-sectional view showing another embodiment of j, 810 is a plan view of the main part of the lower printed circuit board.

In this embodiment, there is a double layer on the upper surface of the lower printed circuit board 51.
．． The contacts 1 and 1 are arranged in parallel, and are always in contact with the conductor 103 provided on the surface of the printed circuit board 510 at the end 102 of the base peak 1j of the movable contact plate 54, and the suppressing piece 84 and the fixed contact 1 This is a normally open switch with the old one. In this case, the upper printed circuit board 50 has an electrical function and is simply used to align the movable contact plates 54 when the key is not pressed. Therefore, the upper and lower printed circuit boards 50.
51 is not connected with a jumper lead wire as in the above embodiment, but is simply held by a pair of holders 52 and 53.

It is clear that the same effects as in the above embodiment can be obtained in such a 'ft'l configuration.

As explained below, the electronic chestnut machine keyboard switch according to the present invention is formed into a unit by integrally holding the pair of upper and F printed circuit boards and the movable contact plate interposed between these printed circuit boards with a holder. Therefore, assembly work is extremely easy,
Can be done efficiently. In addition, since the free ends of the four movable contacts are pressed down by the key's actuator, the touch of the key is good, and the fixed contacts provided on the printed circuit board and the movable contact plate are highly dust-proof. The effect is very large.

[Brief explanation of drawings]

FIGS. 1(a) and 1(1)) are a 1111-level view and a sectional view taken along the line A-A, showing an example of a conventional keyboard switch. No. 21/1 is also a diagram showing an example of conventional keyboard switch oil. Fig. 1 is a partially cutaway side view of a keyboard section equipped with a keyboard switch according to the present invention. Fig. 4 11116 exploded perspective view of a part of the d-time Suitsuna. rr> 5 Figure 1 is a plan view of the printed circuit board before division. FIG. 6 is an enlarged sectional view of the main parts of the printed circuit board. FIG. 7 is a sectional view showing another embodiment of the invention. Figure 8 is a plan view of the main parts of the lower (1!II) printed circuit board. 30...Key, 31-...Keyboard frame, 37...
・Φ actuator, 450'...keyboard switch, 5
0.51...Print base 4m, 52゜53...
... Volta, 54... Movable contact plate, 54b...
Free end, 55, 56, 101...Fixed contact, 84
...Press piece.

Claims (1)

[Claims] A pair of printed circuit boards facing each other, and a pair of printed circuit boards facing each other [! ]'i fixed contacts corresponding to the valley keys provided on at least one side, and a plurality of uJ' movable contact plates corresponding to the /4 keys disposed between the above-mentioned and phantom printed circuit boards. The pair of printed circuit boards and the movable contact plate are held in common by a holder and arranged on the keyboard frame, and the free end of each contact plate is pressed down by the actuator of the corresponding ridge when the corresponding key is pressed. 'Jj!' is an electronic musical instrument that is characterized by board switch.