WO2019026235A1

WO2019026235A1 - Electronic musical instrument

Info

Publication number: WO2019026235A1
Application number: PCT/JP2017/028241
Authority: WO
Inventors: 賢一芝; 和希若山; 佳之平井
Original assignee: ヤマハ株式会社
Priority date: 2017-08-03
Filing date: 2017-08-03
Publication date: 2019-02-07

Abstract

Provided is an electronic musical instrument that can protect an electronic component from static electricity that has been discharged into a screw. According to the present invention, a main body case 10 is cooperatively configured from a lower first case 11 and an upper second case 12. A circuit board 30 is arranged between the first case 11 and the second case 12. A screw 15 is inserted from a bottom surface side (the outside) of a first case 11, passes through a hole in a boss part 14, an insertion hole 25 in a lower case 21, an insertion hole 38 in the circuit board 30, a hole 41 in a copper-foil tape 40, and an insertion hole 26 in an upper case 22, and screwed into a screw hole 16 in the second case 12. The hole 41 in the copper-foil tape 40 is even closer to the screw 15 than an electronic component 31 that is closest to the screw 15. A folded-back part 42 of the copper-foil tape 40 and the portion of a main part 43 that faces the folded-back part 42 are electrically connected to a ground terminal 34 for the circuit board 30.

Description

Electronic musical instrument

The present invention relates to an electronic musical instrument having a configuration in which a screw for fastening a case penetrates a circuit board.

Conventionally, a circuit board on which various electronic components are mounted is provided in a housing of an electronic musical instrument. For example, in the musical instrument of Patent Document 1 below, a circuit board is disposed between the lower case and the upper case. Mounting holes are provided at four corners (corners) of the circuit board, and screws are inserted into these mounting holes, and the screws are screwed into the upper surface plate, whereby the circuit board is fixed to the board base.

Patent No. 4337052

In a housing having a configuration in which two cases are fastened with a screw, the screw may be inserted from the outside, and the head of the screw may be exposed to the outside. The screw head may be configured to fit in a recessed position so that the screw head does not protrude. However, when handling an instrument, static electricity may be discharged to the screw when the user's body with electrostatic contact touches or approaches the screw. When discharged to a screw penetrating the circuit board, static electricity may be transmitted to the electronic component and may adversely affect the electronic component. Therefore, it is necessary to protect the electronic component from static electricity.

By the way, in the electronic musical instrument, in order not to give the influence of static electricity to the electronic component, the space distance between the member such as a screw or the like which receives the static electricity and the electronic component needs at least about 10 mm. If there is a margin in design as a position where the screw penetrates the circuit board, it is possible to select, for example, four corner portions of the circuit board apart from the mounting position of the electronic component. However, in a small-sized musical instrument, there is not enough space, and it is not possible to select a position such as a corner of a circuit board as a screw penetration position, and it may be necessary to dispose the through hole at a position near the electronic component. Then, electronic components close to the screws are likely to be affected by static electricity.

An object of the present invention is to provide an electronic musical instrument capable of protecting an electronic component from static electricity discharged to a screw.

According to the present invention to achieve the above object, according to the present invention, a first case (11), a second case (12) constituting a housing (10) in cooperation with the first case, and a through hole (38) And a ground terminal (34), and the circuit board (30) disposed between the first case and the second case, and inserted from the outside of the first case, A screw (15) for fastening the first case and the second case by being screwed into the second case through the through hole, and the screw among the electronic components mounted on the circuit board A conductive member (40) having a portion (41-1) closer to the screw and having a portion (42) electrically connected to the ground terminal as compared to the electronic component (31) closest to the An electronic musical instrument is provided. In addition, the code in the said parenthesis is an illustration.

According to the present invention, an electronic component can be protected from static electricity discharged to a screw.

It is a perspective view of a part of electronic musical instrument. FIG. 2 is a perspective view of the electronic musical instrument showing a cross section taken along the line AA of FIG. 1; FIG. 2 is a perspective view of a circuit board showing a cross section taken along the line AA of FIG. 1; It is a perspective view of the copper foil tape which shows the cross section which follows the AA of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a part of an electronic musical instrument according to an embodiment of the present invention. The electronic musical instrument 100 has a main body 27 and a neck 23. The main body unit 27 is provided with a keyboard unit KB composed of a plurality of keys. Two hooks are provided on the bottom of the main body 27 opposite to the side on which the keyboard KB is disposed, and a strap (not shown) can be hooked on these hooks. The strap can be put on the shoulder to perform performance such as the operation of the keyboard KB. Also, it is possible to play by placing the bottom of the main body 27 on a support. As described above, although the posture of the electronic musical instrument 100 at the time of playing is not fixed, for convenience of the description of the configuration, the side on which the keyboard portion KB is disposed is the upper side, and the opposite side is the lower side. The exterior of the main body portion 27 is the main body case 10, and the main body portion 27 is provided with a display cover 13 which transmits light of the display portion. The exterior of the neck portion 23 is a neck case 20. The main housing 10 and the neck housing 20 are fastened by screws 15 which are a plurality of fastening members described later.

FIG. 2 is a perspective view of the electronic musical instrument 100 showing a cross section taken along the line AA of FIG. The neck case 20 is configured by the cooperation of the lower case 21 and the upper case 22. The main body case 10 is configured by the cooperation of the lower first case 11 and the upper second case 12. The

cases

21, 22, 11, 12 are all made of resin, and are electrically nonconductive members (nonconductive members). The circuit board 30 is disposed between the first case 11 and the second case 12. Below the circuit board 30, a copper foil tape 40, which is a conductive member (conductive member), is disposed. The lower case 21 has a horizontal portion 24 extending below the circuit board 30 in parallel with the circuit board 30. The horizontal portion 24 is an intervening member interposed between the copper foil tape 40 and the circuit board 30. In the first case 11, bosses 14 that are recessed upward (inward) are formed at a plurality of locations.

FIG. 3 is a perspective view of the circuit board 30 showing a cross section taken along the line AA of FIG. FIG. 4 is a perspective view of the copper foil tape 40 showing a cross section taken along the line AA of FIG. Since the circuit board 30 is disposed from the neck case 20 to the main body case 10, the cross section of the circuit board 30 appears in FIGS. 2 and 3 in the direction in which the keys are arranged. Among the plurality of corner portions (four corners and the like) of the circuit board 30, the

corner portions

30c and 30d appear. Electronic components can be mounted on both the front surface 30 b and the back surface 30 a of the circuit board 30. In FIG. 3, the

electronic components

31, 23, 33 are shown as part of the mounted components, but other mounted components exist. A plurality of through holes 38 are formed in the circuit board 30 (FIG. 3). A plurality of holes 41 (41-1, 41-2, 41-3) are formed in the copper foil tape 40 corresponding to the respective through holes 38 (FIG. 4). A screw 15 is inserted through each of the through hole 38 and the hole 41. In FIG. 4, screws 15-1, 15-2 and 15-3 are shown. After the circuit board 30 is fixed, the positions of the through holes 38 and the holes 41 correspond to the positions of the bosses 14 of the first case 11. Similar sets may exist besides the set of through holes 38, holes 41 and screws 15 shown in FIGS. As a representative, the configuration of the set including the screw 15-1 and the related elements will be described.

As shown in FIG. 2, at the position corresponding to the boss portion 14, an insertion hole 25 is formed in the lower case 21, an insertion hole 26 is formed in the upper case 22, and a screw hole 16 is formed in the second case 12. It is formed. The screw 15-1 is inserted from the bottom side (outside) of the first case 11, and the hole of the boss portion 14, the insertion hole 25 of the lower case 21, the through hole 38 of the circuit board 30, and the hole 41- of the copper foil tape 40. 1 penetrates the insertion hole 26 of the upper case 22 and is screwed into the screw hole 16 of the second case 12. As a result, the first case 11 and the second case 12 are fastened, and the circuit board 30 and the copper foil tape 40 are sandwiched and held between the lower case 21 and the upper case 22. By screwing all the screws 15 to the upper case 22, the neck case 20 and the main body case 10 are completed, and the lower case 21 and the copper foil tape are interposed between the first case 11 and the second case 12. 40, the circuit board 30 and the upper case 22 are fixed together. The female screw groove of the screw hole 16 may be formed by self tapping along with the screwing of the screw 15-1. The configuration of the screw 15 other than the screw 15-1 and the corresponding boss portion 14, the insertion hole 25, the insertion hole 26, and the screw hole 16 is the same as that described for the screw 15-1.

In the electronic musical instrument 100 completed as a product, the head 15 a of the screw 15 is exposed to the outside. In practice, the head 15a fits in the recessed portion of the boss portion 14, but the user's body may approach or touch the head 15a. In particular, when playing by putting the strap on the shoulder, there are many opportunities for a finger to approach the head 15a. When the user's body is charged with static electricity, the static electricity may be discharged to the head portion 15a, so it is necessary to take measures so as not to affect the mounted components of the circuit board 30.

Therefore, in the present embodiment, the copper foil tape 40 is provided in order to escape to the ground 39 (FIG. 4) provided on the electronic musical instrument 100 without transmitting the electricity discharged to the screw 15 to the mounted components. . As shown in FIG. 3, a ground terminal 34 is provided at a corner 30 c which is one of the plurality of corners of the circuit board 30. The ground terminal 34 is provided on both the front surface 30 b and the back surface 30 a of the circuit board 30, but may be provided on one side.

As shown in FIG. 4, the main portion 43 of the copper foil tape 40 is disposed substantially parallel to the back surface 30 a along the back surface 30 a which is one of the substrate surfaces of the circuit board 30. The main portion 43 is formed to pass through the arrangement position of the screws 15-1, 15-2, 15-3. Since the horizontal portion 24 of the lower case 21 intervenes between the circuit board 30 and the main portion 43, the main portion 43 of the copper foil tape 40 is against the back surface 30 a of the circuit board 30 in the range where the horizontal portion 24 exists. Do not touch Thereby, the main part 43 and the circuit board 30 are electrically insulated. The copper foil tape 40 has a folded portion 42 folded back in the vicinity of the corner 30 c. A screw 17 passes through the folded portion 42 and the main portion 43 in a state in which the corner portion 30 c of the circuit board 30 is sandwiched between the folded portion 42 and the main portion 43. The screw 17 is screwed into the first case 11. As a result, the folded back portion 42 and the portion of the main portion 43 facing the folded back portion 42 reliably contact the ground terminal 34 and are brought into conduction. A connector 36 is electrically connected to the ground terminal 34, and the connector 36 is electrically connected to the ground 39 through a conductor 37. Thus, the electricity discharged to the copper foil tape 40 is guided to the ground 39 through the ground terminal 34, the connector 36 and the lead 37.

The screw 15 is inserted through the hole 41 of the copper foil tape 40. The inner diameter of the hole 41 is equal to or slightly larger than the outer diameter of the cylindrical portion other than the head portion 15 a of the screw 15 and the male screw portion. The inner diameter of the hole 41 is larger than the inner diameter of the through hole 38. In the state after assembly, the hole 41 and the screw 15 may be in contact with each other, but may not be in contact with each other. Since the hole 41 is shaped so as to surround the screw 15, even if the axis of the screw 15 and the center of the hole 41 are slightly misaligned, the closest distance between the inner edge of the hole 41 and the outer shell of the screw 15 is It does not become excessive. Since the shortest distance between the inner edge of the hole 41 and the outer shell of the screw 15 is sufficiently short, the electricity discharged to the screw 15 is surely induced to the copper foil tape 40.

Taking the screw 15-1 as an example, it is assumed that the mounted component arranged at the position closest to the screw 15-1 (the shortest distance between the closest parts) is the electronic component 31. The electronic component 31 is, for example, a CPU. The distance between the inner edge of the hole 41-1 and the outer periphery of the screw 15 is designed to be sufficiently short with respect to the distance between the screw 15-1 and the electronic component 31. That is, the hole 41-1 is a portion closer to the screw 15-1 compared to the electronic component 31. Thus, the electricity discharged to the screw 15-1 is induced to the copper foil tape 40 without being induced to the electronic component 31, and the occurrence of an electrical adverse effect on the electronic component 31 is avoided. Similarly for the screws 15-2 and 15-3, the distance between the inner edge of the hole 41 and the outer shell of the screw 15 is sufficiently short for the

electronic components

32 and 33 closest to each other.

According to the present embodiment, the copper foil tape 40 has a hole 41 which is a portion closer than the electronic component (31 and the like) closest to the screw 15, and a portion electrically connected to the ground terminal 34 (folded portion 42 Etc.). Thereby, the static electricity discharged to the screw 15 is not transmitted to the electronic components 31 and the like, and is induced to the ground terminal 34 through the copper foil tape 40, so that the electronic components 31 can be prevented from being affected. . Therefore, the electronic component 31 can be protected from static electricity discharged to the screw 15.

Further, since the horizontal portion 24 of the lower case 21 made of a nonconductive member is interposed between the main portion 43 of the copper foil tape 40 and the circuit board 30, the substrate surface (main portion 43) and the copper foil tape 40 Contact can be avoided and both can be electrically isolated. Thereby, the static electricity discharged to the screw 15 can be prevented from being transmitted to the circuit board 30, and the electronic component 31 can be protected. Although the horizontal part 24 is a part of the lower case 21 and an increase in the number of parts is avoided, from the viewpoint of insulation, the horizontal part 24 is a member different from the lower case 21, for example, a non-dedicated member. It may be a conducting member.

In addition, since the holes 41 are disposed so as to surround the screws 15, the distance between the holes 41 and the screws 15 does not become excessive even if there is a positional deviation between the screws 15 and the copper foil tape 40 in the horizontal direction. Thereby, the static electricity discharged to the screw 15 can be reliably transmitted to the copper foil tape 40. From this point of view, the hole 41 may not be completely circular, and may have a shape surrounding the screw 15. Therefore, the copper foil tape 40 may be formed in a substantially annular shape in which a portion is lost, instead of the hole 41. The substantially annular shape does not have to be approximate to a circle, and may be another shape such as a rectangle.

Further, by disposing the copper foil tape 40 at a position close to the back surface 30 a of the circuit board 30, the holes 41 substantially surround the through holes 38. Thereby, even if there is a positional deviation between the screw 15 and the circuit board 30 in the horizontal direction, the hole 41 can be present at a position closer to the electronic component closest to the screw 15 than the screw 15. Also in this case, the static electricity discharged to the screw 15 can be reliably transmitted to the copper foil tape 40.

Further, at least one of the plurality of through holes 38 of the circuit board 30 is formed in an area other than the corner of the circuit board 30. Thus, the protection function of the electronic component from static electricity can be secured even under the mounting condition where the screw 15 must be disposed near the electronic component.

In place of the copper foil tape 40, a conductive member made of another material may be employed. The conducting member may be, for example, an aluminum foil tape or a metallic sheet metal. Further, the shape of the conductive member is not limited to a sheet type such as a tape, and the conductive member may be constituted by a plurality of pieces.

The electronic musical instrument to which the present invention can be applied includes not only a keyboard musical instrument but also an electronic musical instrument in which strings are arranged like a guitar.

Although the present invention has been described in detail based on its preferred embodiments, the present invention is not limited to these specific embodiments, and various embodiments within the scope of the present invention are also included in the present invention. included.

DESCRIPTION OF SYMBOLS 10 Body housing 11 1st case 12 2nd case 15 Screw 30 Circuit board 34 Ground terminal 38 Through hole 40 Copper foil tape 41 Hole 42 Folded portion

Claims

The first case,
A second case forming a housing in cooperation with the first case;
A circuit board having a through hole and a ground terminal and disposed between the first case and the second case;
A screw for fastening the first case and the second case by being inserted from the outside of the first case, screwed to the second case through the through hole of the circuit board;
A conductive member having a portion closer to the screw and having a portion electrically connected to the ground terminal as compared with the electronic component closest to the screw among the electronic components mounted on the circuit board; Electronic musical instrument with.
The electronic musical instrument according to claim 1, wherein the conductive member is disposed along a substrate surface of the circuit board, and an intervening member made of a nonconductive member is interposed between the conductive member and the substrate surface.
The electronic musical instrument according to claim 1, wherein the portion of the conductive member close to the screw is disposed so as to surround the screw.
The electronic musical instrument according to claim 3, wherein the portion of the conductive member close to the screw is disposed to surround the through hole.
The electronic musical instrument according to any one of claims 1 to 4, wherein the through hole is formed in an area other than the corner of the circuit board.
The electronic musical instrument according to any one of claims 1 to 5, wherein the conductive member is a copper foil tape.