JPS6217949Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a keyboard device for an electronic musical instrument, and in particular, a key switch corresponding to each key is incorporated between a keyboard frame on which a plurality of keys are attached and a printed circuit board held parallel to the keyboard frame. The present invention relates to a structured keyboard device.

In conventional keyboard devices for electronic musical instruments such as electronic organs, a key switch with a metal contact such as a leaf contact piece was provided separately for each key, so the key switch and its mounting structure were complex and had a large number of parts. However, many man-hours are required for assembly, which makes the keyboard device complicated, large and expensive, and the contacts of the key switch tend to chatter when they are brought into contact.

In order to solve this problem, we applied recent digital technology to time-divisionally scan the key presses of each key using a movable contact in a connected, integrated structure, thereby determining which key was pressed. Detected,
The applicant has developed an electronic musical instrument that has a simple structure and can be easily made compact, in which a musical tone forming circuit generates a musical tone corresponding to a pressed key.

The purpose of this invention is to further simplify the installation structure of the key switch, and the movable contacts of the above-mentioned connected integral structure are formed on a printed circuit board corresponding to the arrangement spacing of each key. A key switch with a simple structure consisting of a fixed contact that is turned on and off by a contact is attached to the keyboard frame together with the above-mentioned printed circuit board.A board holder is integrally molded into the keyboard frame using synthetic resin, and is held by this. By holding the movable contacts between the printed circuit board and the keyboard frame, the number of man-hours in the keyboard device manufacturing process can be significantly reduced, and the movable and fixed contacts of the key actuator and the key switch can be This allows the positional relationship between the two to be maintained with high precision.

Hereinafter, embodiments of this invention will be described with reference to the accompanying drawings. FIG. 1 is a longitudinal cross-sectional view of a key according to a first embodiment of this invention, in which 1 is a key, the rear end of which protrudes somewhat from a window 2a provided in a rising rear portion of a keyboard frame 2. , the fulcrum groove 1a provided on the upper surface fits into the upper edge of the window 2a, and the spring holding hole 1b provided on the lower surface on the front side thereof is located between the spring holder 3 provided on the keyboard frame 2. The arm portion 1c for regulating the upward movement position is rotated upwardly by the interposed compression spring 4, and comes into contact with the lower surface of the key stopper 5 to restrict the upward movement position and is held in a substantially horizontal state. ing.

Reference numeral 6 denotes a printed circuit board disposed on the bottom surface of the keyboard frame 2, and a key switch 7 is provided on the printed circuit board 6 at a position corresponding to each key. Actuator 1d for each key that descends when the key is pressed
Closed by.

For example, as shown in an enlarged view in FIG. 5, this key switch includes a pair of fixed contacts 7a and 7b arranged in a row at a small distance from each other according to a printed pattern on a printed circuit board 6, and a pair of fixed contacts 7a and 7b arranged in a row at a small distance from each other over the top of the fixed contacts 7a and 7b. The movable contacts 7c are made of a conductive elastic material such as conductive rubber or elastic metal, and have a connected integral structure corresponding to a plurality of fixed contacts.

The movable contact 7c consists of a central hollow movable part 7c ₁ and thick fixed parts 7c ₃ disposed on both sides of the movable part 7c 2 with thin supporting pieces 7c ₂ interposed therebetween.

Reference numerals 8 and 9 denote first and second printed circuit board holders that constitute a circuit board holder for holding the printed circuit board 6, for example, the through hole 2 of the keyboard frame 2.
It extends over the upper and lower surfaces of the keyboard frame 2 through c and 2d and is formed by integral molding of synthetic resin.
In the second printed circuit board holder 9, the upper part of the keyboard frame 2 is a spring holder 3.
and become one.

Printed circuit board fitting grooves 8a and 9a are formed in each of the printed circuit board holders 8 and 9 along the longitudinal direction, and when installing the printed circuit board 6, it is necessary to install the printed circuit board 6 in the longitudinal direction, that is, perpendicular to the plane of the paper in FIG. If the printed circuit board holding parts 8 and 9 are molded with soft synthetic resin with appropriate elasticity,
It is also possible to fit one side edge of the printed circuit board 6 into one of the printed circuit board holders and insert the other side into the printed circuit board 6 while curving it in the width direction.

Reference numeral 10 denotes a key guide for regulating the swinging of the key 1 in the left-right direction, and is formed around the cut-out portion 2e of the key frame 2, integrally with the key stopper 5.

The spring pedestal 3, the first and second printed circuit board holders 8, 9, the key stopper 5, the key guide 10, etc. are all made by placing molds (not shown) above and below the key frame 2, and molding them into appropriate shapes. For example, by pouring synthetic resin liquid through the holes in the mold,
It is integrally molded on the upper and lower surfaces of the keyboard frame 2, and can be formed in an accurate position and connected to the keyboard frame 2 without using fixing means such as screws.

When molding these parts at once, it goes without saying that a runner part is required to connect the key guide 10, printed circuit board holding part 8, spring pedestal 3, etc., although not shown.

FIG. 2 is a sectional side view of a main part of a second embodiment of this invention, in which the board holder 11 has a first printed board holder 11b having a groove 11a that fits into one side edge of the printed board 6'. , a second printed circuit board holder 11d made of a protruding strip having a claw portion 11c that is inserted into a through hole 6'a formed in the printed circuit board 6' and engaged with the edge thereof; Intermediate support part 11 that supports the intermediate part close to the through hole 6'a of
e, the first and second printed circuit board holding parts 11b, 11d and the intermediate support part 1 on the upper surface side of the keyboard frame 2.
1e and a runner portion 11f integrally connecting the runner portion 1e and the runner portion 11f.

A spacer 12 is formed integrally with the spring holder 3, supports the vicinity of the free end of the printed circuit board 6', and maintains a constant distance from the keyboard frame 2.

The board holder 11, the spring pedestal 3, and the spacer 12 in this embodiment are also formed integrally with the keyboard frame 2 from synthetic resin, as in the case of the first embodiment described above. be done.

In the case of this second embodiment, the printed circuit board 6'
When installing the printed circuit board 6', insert one side edge of the printed circuit board 6' into the groove 11a of the first printed circuit board holding section 11b of the board holder 11 at a slight angle from below, and then insert the printed circuit board 6' into the groove 11a of the first printed circuit board holding section 11b of the board holder 11. Through hole 6'
When inserting it into the printed circuit board 6' by slightly bending it and pushing it into the horizontal position, the claw part 11c will be inserted into the printed circuit board 6'.
The printed circuit board 6' is easily installed without the need for any equipment.
The printed circuit board holding section 11b, the claw section 11c of the second printed circuit board holding section 11d, and the intermediate support section 11e.
It is held in place without wobbling.

In each of these embodiments, the movable contact 7c of the key switch 7 is attached to a printed circuit board 6 or 6 held parallel to the lower surface of the keyboard frame 2 by a board holder 8, 9 or 11 integrally formed on the keyboard frame 2. Since the thick fixing portion _7c3 is sandwiched and held between the keyboard frame 2 and the keyboard frame 2, the positional relationship with respect to the actuator 1d and the fixed contacts 7a and 7b can be accurately and reliably maintained.

When the key 1 is pressed down by a key press operation, the actuator 1d descends and presses and deforms the movable part _7c1 of the movable contact 7c made of a conductive elastic material through the through hole 2b formed in the keyboard frame 2. , short-circuit between the fixed contacts 7a and 7b formed on the printed circuit board 6 by their lower surfaces.

Therefore, the fixed contacts corresponding to the depression of the key switch 7 are closed without any chattering (see FIG. 1). Then, which key has been pressed is detected by time-division scanning by a circuit (not shown).

FIG. 3 is a sectional view of a main part of the third embodiment of this invention, and FIG. 4 is a view seen from the direction of arrow A in FIG. 3, and the same parts as in FIG. , and the explanation thereof will be omitted.

The board holder 13 in this embodiment includes a first printed board holder 13b having a groove 13a that fits into one side edge of the printed board 6'', and a first printed board holder 13b that fits loosely into a through hole 6a'' of the printed board 6'', for example. Second printed circuit board holder 1 consisting of a columnar protrusion
3c and a runner portion 13d that connects the two, and when the printed circuit board 6'' is attached to the second printed circuit board holding portion 13c, an arc-shaped protrusion 13e and a printed circuit board that sandwich the printed circuit board from above and below. A claw 13 that fits into a small through hole 6b″ provided at 6″
A flexible horseshoe-shaped claw holding part 13g having a tip "f" is provided in parallel with the lower surface of the keyboard frame 2 and protruding rearward.

This printed circuit board holder 13 is also formed integrally with the keyboard frame 2 from a suitably elastic synthetic resin, as in the first and second embodiments.

7a and 7b are fixed contacts of the key switch 7 formed by a printed pattern on the top surface of the printed circuit board 6'', and 7c is positioned and held on the upper part by a holding means (not shown) to turn on and off the fixed contacts 7a and 7b. A movable contact made of a soft material such as conductive rubber.

In the third embodiment configured as described above, in order to mount the printed circuit board 6'', the through hole 6a'' is inserted into the second printed circuit board holding portion 13 of the board holder 13.
c and push it in the direction of arrow B in FIG. 3, its front edge will fit into the groove 13a of the first printed circuit board holder 13b, and at the same time the claw 13f will fit into the small through hole 6b''. As a result, the printed circuit board 6'' cannot be pulled out in the direction opposite to the arrow B, and the intermediate portion of the printed circuit board 6'' is held between the claw holding portion 13g and the arcuate protrusion 13e, and the second printed circuit board holding portion 13c and the claw 13
It is positioned and held by f. Therefore, mounting of the printed circuit board is extremely easy, and moreover, it is reliably positioned and held.

As described above, according to this invention, the key switch and its mounting structure in the keyboard device of an electronic musical instrument are extremely simple, and the occurrence of chattering can be suppressed. By integrally molding the printed circuit board into the frame, the mounting work of the printed circuit board is extremely simple, and the number of man-hours and parts are reduced, making it possible to provide the product at a low cost.The mounting position can also be set accurately, thereby Hold the movable contacts of the key switch between the keyboard frame and the fixed contacts and actuator while maintaining the correct positional relationship,
This ensures the operation of the key switch.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the key of the first embodiment of this invention, Fig. 2 is a side sectional view of main parts of the second embodiment of this invention, and Fig. 3 is a third embodiment of this invention. 4 is a bottom view seen from the direction of arrow A in FIG. 3, and FIG. 5 is an enlarged view of the key switch portion in FIG. 1. 1...Key, 2...Keyboard frame, 3...Spring holder, 4...Compression spring, 5...Key stopper, 6, 6', 6''...Printed circuit board, 7...Key switch, 10... Key guide, 11, 13...
Substrate holder, 12...spacer.

Claims (1)

[Claims for Utility Model Registration] A keyboard frame on which a plurality of keys are mounted, and a keyboard frame fixed to the lower part of the keyboard frame in parallel with the keyboard frame via a board holder, with one key corresponding to each of the plurality of keys. A printed circuit board on which a plurality of fixed contacts are formed, and a movable part in the center and a thin support piece on both sides of the printed circuit board, which is arranged on the printed circuit board and forms a common connection integral structure for the plurality of fixed contacts. a key switch constituted by a movable contact having a thick fixed portion disposed therein, the board holder being integrally molded on the keyboard frame from synthetic resin, and the board holder holding the movable contact between the printed circuit board held by the keyboard frame and the keyboard frame;
A keyboard device for an electronic musical instrument, characterized in that actuators fixed to each key move down through a through hole formed in the keyboard frame when a key is pressed, thereby closing the key switch.