JP2003141967A - Dome switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dome switch which can absorb slack grown up at a circuit object. SOLUTION: The dome switch is equipped with a front sheet 22 with dome- shaped projected section 27 which projects toward outside and can also be projected reversely toward inside where an electrode 28 is arranged, an FPC 24 as a circuit object with a contact 35 to get in touch with the electrode 28 arranged at a projected section of the front sheet when it is reversely projected toward inside, and a spacer sheet 23 interposed between the front sheet 22 and the FPC 24 forming a through-hole 29 securing contact between the electrode 28 and the contact 35. A slack-absorbing space section 31 is formed in the spacer sheet 23 to absorb slack 42 grown up at the FPC 24 when bent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dome switch including a front sheet having a dome-shaped protruding portion, a spacer sheet, and a circuit body, and a movable side contact and a fixed side contact. The present invention relates to a dome switch that can be bent in the mountain fold direction.

[0002]

2. Description of the Related Art In FIG. 10, a dome switch 1 is
The front sheet 2, the spacer sheet 3, and the circuit body 4 are provided. A plurality of dome-shaped protrusions 5 are formed on the front sheet 2, and electrodes 6 are provided on the inner tops thereof. Through holes 7 are formed in the spacer sheet 3 at positions corresponding to the respective protrusions 5, and the inverted protrusions 5 are inserted therein. Switch circuits (not shown) are arranged in the circuit body 4 in an appropriate pattern. A contact 8 for the electrode 6 is provided on the switch circuit.

In the dome switch 1, when the protruding portion 5 is pushed down by a switch operation and the inverted electrode 6 of the protruding portion 5 comes into contact with the contact 8 of the circuit body 4, conduction of a switch circuit (not shown) is obtained. There is.

Reference numeral 9 indicates an adhesive layer for fixing the front sheet 2 and the spacer sheet 3. Further, reference numeral 10 indicates an adhesive layer for fixing the spacer sheet 3 and the circuit body 4. In addition, quotation mark 1
Reference numeral 1 denotes an adhesive layer for installing the dome switch 1 on the attached member 12. The dome switch 1 is installed on the flat surface of the attached member 12.

[0005]

By the way, in the dome switch 1, when the installation surface for the dome switch 1 is composed of a horizontal surface 13 and an inclined surface 14 as shown in FIG. 10, It has the following problems.

That is, the dome switch 1 is placed on the horizontal plane 1.
When bent in the mountain fold direction in accordance with the connecting portion of 3 and the inclined surface 14, since the bending radii from the front sheet 2 to the circuit body 4 are different from each other, the circuit body 4 is loosened at the position of the arrow A, and There is a problem that the looseness hinders the installation, aesthetics and function of the dome switch 1.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dome switch capable of absorbing looseness generated in a circuit body.

[0008]

A dome switch according to the present invention as set forth in claim 1 for solving the above-mentioned problems is a dome switch that can be bent in a mountain fold direction at a predetermined position, and protrudes to the outer surface side. Also, a front sheet having a dome-shaped projecting portion that can be inverted on the inner surface side, a movable-side contact that is displaced when the projecting portion is reversed, and a fixed-side contact that faces and contacts the movable-side contact. And a circuit body having the fixed side contact, and a through hole interposed between the front sheet and the circuit body and for ensuring contact between the movable side contact and the fixed side contact. One or a plurality of spacer sheets, and a slack absorbing space portion that absorbs slack in the circuit body that occurs during bending is formed in a portion of the spacer sheet corresponding to the predetermined position. That.

According to a second aspect of the present invention, in the dome switch according to the first aspect, a part of the spacer sheet is necessarily interposed between the slack absorbing space portion and the front sheet. Is characterized by.

A dome switch according to a third aspect of the present invention is the dome switch according to the first or second aspect, which has a circuit body mounting surface for the circuit body on one side and an adhesive fixing surface for a member to be mounted. It is characterized in that it further comprises an adhesive sheet provided on the other side, and that the circuit body is provided with an external connection means used for electrical connection to the outside.

According to a fourth aspect of the present invention, the dome switch according to the third aspect is characterized in that the external connecting means has an edge connector terminal or a connector.

A dome switch according to a fifth aspect of the present invention is the dome switch according to the fourth aspect, wherein the external connection means further has a wiring circuit portion drawn out from the circuit body body.

A dome switch according to a sixth aspect of the present invention is characterized in that, in the dome switch according to any of the third to fifth aspects, the adhesive sheet has a release paper on the adhesive fixing surface.

According to the present invention as set forth in claim 1,
In addition to the front sheet, the spacer sheet, and the circuit body, the movable and fixed contacts are provided. With these configurations, the switch operation operates as follows. That is, when the movable side contact and the fixed side contact come into contact with each other after the protruding portion is pushed down and the protruding portion is inverted, a conductive state is obtained. When the depression of the protruding portion is released and the protruding portion returns to the original state, the conduction state is released accordingly. On the other hand, since the slack absorbing space is formed in the spacer sheet, the dome switch of the present invention operates as follows. That is, when bent in the mountain fold direction at a predetermined position,
The slack of the circuit body generated during the bending is absorbed by the slack absorption space portion. Explaining in a little more detail, the circuit body gradually loosens as the dome switch is bent,
The slack of the circuit body is absorbed in a state where it is inserted into the slack absorption space. Therefore, the looseness of the circuit body does not hinder the installation, aesthetics, and function of the dome switch.

According to the present invention described in claim 2,
Since a part of the spacer sheet is interposed between the slack absorbing space portion and the front sheet, the function as the spacer sheet is maintained. That is, the function as a member for preventing the deformation of the front sheet is maintained.

According to the present invention described in claim 3,
Since the circuit body has an external connecting means, it is possible to install the pressure-sensitive adhesive sheet at a site according to the needs of the user. Further, the fixing is performed only by attaching the adhesive fixing surface to the member to be attached, and the member can be easily attached.

According to the present invention described in claim 4,
Electrical connection to the outside is made via the edge connector terminal or the connector.

According to the present invention described in claim 5,
Electrical connection with the outside is made within the length of the wired circuit portion drawn out from the circuit body.

According to the present invention described in claim 6,
The adhesive fixing surface is protected until the final use. Further, it becomes possible to carry the switch with the release paper on the adhesive fixing surface.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view showing a first embodiment of the dome switch of the present invention. Further, FIG. 2 is an enlarged sectional view of the dome switch of the first embodiment, and FIG. 3 is an enlarged sectional view showing an installed state of the dome switch of the first embodiment.

In FIG. 1, a polydome switch according to the present invention (corresponding to the dome switch described in the claims) shown by reference numeral 21 is provided with a front sheet 22, a spacer sheet 23 and an FPC 24. There is. Further, it is configured by including an adhesive sheet 25 required for installation, an electrode 28 and a contact point 35 described later. The polydome switch 21 of the present invention having such a configuration
Is a switch that can be bent in the mountain fold direction at a predetermined position, and can be installed, for example, on a member to be attached indicated by reference numeral 26.

First, the above-mentioned components will be described in detail, and then the assembling and operation of the polydome switch 21 will be described.

In FIGS. 1 and 2, the front sheet 2 described above is used.
2 has flexibility, and has a plurality of protrusions 27.
Are formed. Each of the projecting portions 27 is formed in a dome shape that projects to the outer surface side and can be inverted to the inner surface side. Further, the FPC is formed on the inner surface of each protrusion 27.
An electrode 28 (corresponding to the movable side contact described in the claims) for 24 is provided. The electrode 28 is
It is provided on the top of the inner surface.

Explaining the front sheet 22 in more detail, the front sheet 22 is a synthetic resin sheet member made of, for example, polyethylene terephthalate (PET), and is hot pressed (pressure is applied from the inner surface side to the outer surface side). ), The protrusion 27 is formed. The electrode 28 provided on the top of the inner surface of each protrusion 27 is made of carbon or the like (in the case of the electrode 28 made of carbon, it is provided by printing).

The front sheet 22 is originally transparent because it is made of the above-mentioned material.
The characters “N” and “1” to “4” are printed (printed in the vicinity of the protrusion 27). Similarly, the background color is also printed in black on the inner surface (the electrode 28 made of carbon is provided after the printing).

The spacer sheet 23 is a flexible sheet member made of synthetic resin such as polyethylene terephthalate (PET), and functions as a member for preventing the deformation of the front sheet 22. . In addition, the spacer sheet 23 has the protrusion 2
It also functions as a member to secure the stroke size of No. 7 (a positive function that has not been available in the past).

The spacer sheet 23 will be described in more detail. The spacer sheet 23 has adhesive layers on the front and back surfaces so that the front sheet 22 and the FPC 24 can be fixed to the front and back surfaces, respectively. Has become. Further, the spacer sheet 23 has a plurality of through holes 29.
And a plurality of air escape portions 30 are provided, and the inverted protrusions 27 can be inserted, and the air existing on the inner surface side when the protrusions 27 are inverted can be appropriately escaped. You can do it. Further, the spacer sheet 23 has a slack absorbing space portion 31, which is a feature of the present invention, and can absorb the slack 42 (described later) of the FPC 24 that occurs during bending.

Each through hole 29 is formed in accordance with the position of the corresponding protruding portion 27. In addition, each through hole 2
9 are each formed so as to have a diameter larger than the diameter of the corresponding protrusion 27 (which may be the same as the diameter of the protrusion 27).

Each of the air escape portions 30 has a slit shape, and each of the through holes 2 arranged in the longitudinal direction of the spacer sheet 23.
It is formed between 9. In addition, each air escape section 30
Are formed so as to respectively communicate with the corresponding through holes 29.

The slack absorption space portion 31 is a groove recessed from the FPC 24 side toward the front sheet 22 side. In the present embodiment, the groove-shaped slack absorption space portion 31 extends along the longitudinal direction of the spacer sheet 23. It is formed straight from end to end. The position where the slack absorbing space portion 31 is formed is
It corresponds to the bending position of the polydome switch 21, and the width and depth of the slack absorption space portion 31 are F
It is appropriately formed according to the slack of the PC 24.

In the present embodiment, a part of the spacer sheet 23 is always interposed between the slack absorbing space portion 31 and the front sheet 22, and the function as the spacer sheet 23 is maintained. That is, the function as a member for preventing the deformation of the front sheet 22 is maintained (if the deformation of the front sheet 22 is not affected, it is not necessary to interpose a part of the spacer sheet 23). And).

In the present embodiment, the spacer sheet 23 is formed in a sheet shape having, for example, a thickness that is about half the dimension that allows the protrusion 27 to make the maximum stroke. For example, the thickness of the front sheet 22 (excluding the height of the protrusions 27) is 125 μm, the dimension by which the protrusions 27 can make the maximum stroke is 1.5 mm (the height of the protrusions 27 is 750 μm), and the spacer The thickness of the sheet 23 is 750 μm.

The FPC 24 (FPC: flexible printed circuit) corresponds to the circuit body described in the claims and has a circuit body main body having a plurality of switch circuits 32 arranged in a desired pattern. 33
And external connection means 3 used for electrical connection with the outside
And 4 are provided.

On the spacer sheet 23 side of the circuit body 33, a plurality of contacts 35 (corresponding to the fixed contacts in the claims) with which the electrodes 28 come into contact are provided. Further, near the center of the circuit body 33, the air escape hole 3 communicating with the air escape portion 30 of the spacer sheet 23 is formed.
6, 36 are formed through. In this embodiment,
The thickness of the FPC 24 is 100 μm. The circuit body described in the claims includes an FPC (FPC2
It is not limited to 4) (provided that it can be bent).

The external connection means 34 is provided with a connection circuit part 37 connected so as to be drawn out from the circuit body 33, and a plurality of edge connector terminals 38 provided at the tip of the connection circuit part 37. Has been done. Connection circuit section 3
Reference numeral 7 has an appropriate length, and the switch circuit 32 drawn from the circuit body 33 is arranged therein. Further, the switch circuits 32 drawn out from the circuit body 33 are connected to the corresponding edge connector terminals 38, respectively.

The pressure-sensitive adhesive sheet 25 is formed so that the FPC 24 can be adhered and fixed. That is, the adhesive sheet 25 has a circuit body attachment surface for the FPC 24 on one side. In addition, the adhesive sheet 25 is
The other has an adhesive fixing surface for the member 26 to be attached.

The adhesive sheet 25 has air escape holes 39, 39 similar to the air escape holes 36, 36 communicating with the air escape holes 36, 36 of the FPC 24. The air escape hole 3
9 and 39 are formed so that if there is a space in the attached member 26, the air can escape there.

A release paper (not shown) is provided on the adhesive fixing surface of the adhesive sheet 25. The release paper (not shown) is provided to protect the adhesive fixing surface until the final use and to make the polydome switch 21 portable.

The adhesive sheet 25 can also function as a reinforcing member within a range that does not impair the flexibility of the polydome switch 21.

In the present embodiment, the attached member 26 has, for example, a horizontal surface 40 and an inclined surface 41 that is inclined with respect to the horizontal surface 40.
The polydome switch 21 is installed so as to straddle 0 and the inclined surface 41.

In the above structure, the polydome switch 21 is assembled as follows. First, the front sheet 22
Is adhered and fixed to the surface of the spacer sheet 23,
Adhesively fix the FPC 24 to the back surface of the spacer sheet 23,
Next, they are assembled by adhering and fixing them from the FPC 24 side to the circuit body mounting surface of the adhesive sheet 25.

The polydome switch 21 assembled in this way is installed across the horizontal surface 40 and the inclined surface 41 of the member 26 to be attached, as shown in FIG. That is, the polydome switch 21 is placed on the horizontal plane 40.
Then, it is bent in the mountain fold direction in accordance with the connecting portion of the inclined surface 41, and first, for example, adhesive fixing to the horizontal surface 40 is started via the adhesive sheet 25. When the adhesive fixing to the horizontal surface 40 is completed, the remaining portion is then adhesively fixed to the inclined surface 41.
This completes the installation of the polydome switch 21.

At the time of installation, the release paper (not shown) of the pressure-sensitive adhesive sheet 25 is peeled off, and the adhesive fixing surface is attached in close contact with the horizontal surface 40 and the inclined surface 41.
Further, during installation, the slack 42 is generated in the FPC 24 (the bending radius from the front sheet 22 to the FPC 24 is different, which causes the slack 42), but the slack 42 is formed in the slack absorption space portion 31 of the spacer sheet 23. Be absorbed. Explaining in more detail, slack 42 is generated in the FPC 24 as the polydome switch 21 is bent, and the slack 42 gradually increases. However, the slack 42 is absorbed in the slack absorption space portion 31 of the spacer sheet 23. To be done.

Next, the operation of the polydome switch 21 will be described (operation drawings are omitted).

In the state where no load is applied to the protrusion 27 before the switch operation, the shape is maintained by the shape retention of the protrusion 27 itself. Then, when the switch is operated and the protrusion 27 is pushed down (when a load is applied downward), the protrusion 27 buckles and reverses at a certain load while resisting the load due to the depression (at this time). , Click feeling occurs). When the protruding portion 27 buckles or reverses, the downward load is reduced, and the pressing of the protruding portion 27 proceeds smoothly. The inverted protrusion 27 is the spacer sheet 2
The electrode 28, which is inserted into the through hole 29 of No. 3 and provided on the protrusion 27, contacts the contact 35 of the FPC 24 through the through hole 29.

As a result, the switch circuit 32 becomes conductive and the polydome switch 21 is turned on. On the other hand, when the downward load is released, the protrusion 27 returns to the original state. Then, along with this, the conduction state is released, and the polydome switch 21 is turned off.

As described above, the polydome switch 21 of this embodiment
Can absorb the slack 42 of the FPC 24 generated during bending by the slack absorption space portion 31 of the spacer sheet 23. As a result, it is possible to eliminate the factors that hinder the installation and aesthetics of the switch and the function thereof.

Further, the polydome switch 21 of the present embodiment
Shows the slack absorption space portion 31 from the FPC 24 side to the front sheet 2
Since the groove is recessed toward the second side and a part of the spacer sheet 23 is interposed between the slack absorbing space 31 and the front sheet 22, the function as the spacer sheet 23 can be maintained.

Furthermore, the polydome switch 2 of this embodiment
Since No. 1 is provided with the adhesive sheet 25 and the FPC 24 is provided with the external connecting means 34, it can be installed at a site according to the needs of the user or can be easily installed.

Furthermore, since the polydome switch 21 of this embodiment can be electrically connected to the outside through the edge connector terminal 38 (the same applies to the connector 61 described later), the installation is further facilitated. can do.

In addition, according to the present embodiment, if the spacer sheet 23 is thickened and the necessary stroke dimension is secured within the range where flexibility is not impaired, the stroke of the protrusion 27 can be increased (in other words, in other words). For example, depending on the thickness of the spacer sheet 23, the stroke dimension of the protrusion 27 at the time of switch operation can be set to a required dimension).

Next, a dome switch as a second embodiment will be described with reference to FIGS. 4 to 6. FIG. 4 is an exploded perspective view showing a second embodiment of the dome switch according to the present invention. Further, FIG. 5 is an enlarged cross-sectional view of the dome switch of the second embodiment, and FIG. 6 is an enlarged cross-sectional view showing the installation state of the dome switch of the second embodiment. still,
Components that are basically the same as the constituent members of the polydome switch 21 described above are given the same reference numerals, and description thereof will be omitted.

In FIG. 4, the polydome switch of the present invention (corresponding to the dome switch described in the claims) indicated by reference numeral 51 comprises a front sheet 22, a spacer sheet 52 and an FPC 24. There is. In addition, the adhesive sheet 25 and the electrode 28 that are required for installation
And a contact 35. The polydome switch 51 of the present invention having such a configuration is a switch that can be bent in the mountain fold direction at a predetermined position, like the above-described polydome switch 21 (see FIG. 1). It can be installed on the member 26.

In FIGS. 4 and 5, the spacer sheet 52 comprises an upper spacer sheet 53 and a lower spacer sheet 54. That is, the spacer sheet 52 of the present embodiment is composed of two layers (the number of lower layer spacer sheets 54 may be increased to three or more layers). Further, the spacer sheet 52 has the slack absorbing space portion 31, similarly to the spacer sheet 23 (see FIG. 1) described above. Further, the spacer sheet 52 is similar to the above-mentioned spacer sheet 23 (see FIG. 1) in that it is the front sheet 22.
It functions as a member to prevent deformation of
It functions as a member for ensuring the stroke size of the protrusion 27.

The upper-layer spacer sheet 53 and the lower-layer spacer sheet 54 are both sheet members made of synthetic resin made of, for example, polyethylene terephthalate (PET), and the upper-layer spacer sheet 53 is formed thinner than the lower-layer spacer sheet 54. ing. In this embodiment, the upper spacer sheet 53 has a thickness of 150 μm, and the lower spacer sheet 54 has a thickness of 300 μm.
The upper spacer sheet 53 functions as a sheet member for fine adjustment when securing the stroke size of the protrusion 27.

The upper spacer sheet 53 has adhesive layers on the front and back surfaces, and the front sheet 22 and the lower spacer sheet 54 can be fixed to the front and rear surfaces, respectively. Further, the upper spacer sheet 53 has a plurality of through holes 29.

In this embodiment, the lower layer spacer sheet 54 is configured to have, for example, two divided lower layer spacer sheets 55, 55. The divided lower layer spacer sheets 55, 55 have adhesive layers on the front and back surfaces, and the upper spacer sheet 53 and the FPC 24 can be fixed to the front and back surfaces, respectively. Further, the divided lower layer spacer sheets 55, 55 have a plurality of through holes 29 and a plurality of air escape portions 30 which are the same as the upper layer spacer sheet 53 by combining these two (of the divided lower layer spacer sheets 55, 55). The diameter of the through hole 29 is formed to be larger than or equal to the diameter of the through hole 29 of the upper spacer sheet 53. If the diameter is large, a large area for air escape can be taken and the click feeling is impaired. Not).

Upper layer spacer sheet 53 and lower layer spacer sheet 54 (divided lower layer spacer sheets 55, 55)
When the upper-layer spacer sheet 53 and the lower-layer spacer sheet 54 (divided lower-layer spacer sheets 55, 55) are stacked to form the spacer sheet 52, the upper-layer spacer sheet 53 and the lower-layer spacer sheet 54 (divided lower-layer spacer sheets 55, 55) are The respective through holes 29 are made to coincide with each other. In addition, by overlapping the divided lower layer spacer sheets 55, 55 on the upper layer spacer sheet 53 at intervals, a slack absorption space portion 31 that is a straight groove from end to end is formed along the longitudinal direction of the spacer sheet 52. It is like this.

The slack absorbing space portion 31 of the spacer sheet 52 is directed from the FPC 24 side toward the front sheet 22 side in a state where the upper layer spacer sheet 53 and the lower layer spacer sheet 54 (divided lower layer spacer sheets 55, 55) are laminated. It is a recessed groove and is formed at a position corresponding to the bending position of the polydome switch 51. Also, FPC
The width and the depth are appropriately formed according to the size of the slack 42 generated in 24.

In the above structure, the polydome switch 51 is assembled as follows. First, the front sheet 22
The upper spacer sheet 53 and the lower spacer sheet 5
4 are laminated and fixed to the surface of the spacer sheet 52 formed so as to have the slack absorption space portion 31, and F
The PC 24 is assembled by adhering and fixing the PC 24 to the back surface of the spacer sheet 52, and then adhering and fixing these from the FPC 24 side to the circuit body mounting surface of the adhesive sheet 25.

The polydome switch 51 thus assembled is installed across the horizontal surface 40 and the inclined surface 41 of the attached member 26, as shown in FIG. That is, the polydome switch 51 is placed on the horizontal plane 40.
Then, it is bent in the mountain fold direction in accordance with the connecting portion of the inclined surface 41, and first, for example, adhesive fixing to the horizontal surface 40 is started via the adhesive sheet 25. When the adhesive fixing to the horizontal surface 40 is completed, the remaining portion is then adhesively fixed to the inclined surface 41.
This completes the installation of the polydome switch 51.

At the time of installation, the release paper (not shown) of the pressure-sensitive adhesive sheet 25 is peeled off, and the adhesive fixing surface is attached in close contact with the horizontal surface 40 and the inclined surface 41.
In addition, during installation, the slack 42 is generated in the FPC 24 (the bending radius from the front sheet 22 to the FPC 24 is different, which causes the slack 42), but the slack 42 is in the slack absorption space portion 31 of the spacer sheet 52. Be absorbed. Explaining in more detail, slack 42 is generated in the FPC 24 as the polydome switch 51 is bent, and the slack 42 gradually increases. However, the slack 42 is absorbed in the slack absorption space 31 of the spacer sheet 52. To be done.

Next, the operation of the polydome switch 51 will be described (operation drawings are omitted).

In the state where the load is not applied to the protrusion 27 before the switch operation, the shape is maintained by the shape retention of the protrusion 27 itself. Then, when the switch is operated and the protrusion 27 is pushed down (when a load is applied downward), the protrusion 27 buckles and reverses at a certain load while resisting the load due to the depression (at this time). , Click feeling occurs). When the protruding portion 27 buckles or reverses, the downward load is reduced, and the pressing of the protruding portion 27 proceeds smoothly. The inverted projection 27 is the spacer sheet 5
The electrode 28, which is inserted into the second through hole 29 and provided on the protrusion 27, contacts the contact 35 of the FPC 24 through the through hole 29.

As a result, the switch circuit 32 becomes conductive and the polydome switch 51 is turned on. On the other hand, when the downward load is released, the protrusion 27 returns to the original state. Then, along with this, the conduction state is released, and the polydome switch 51 is turned off.

As described above, the polydome switch 51 of this embodiment
Can absorb the slack 42 of the FPC 24 generated during bending by the slack absorption space portion 31 of the spacer sheet 52. As a result, it is possible to eliminate the factors that hinder the installation and aesthetics of the switch and the function thereof.

In addition, the polydome switch 51 of the present embodiment
Shows the slack absorption space portion 31 from the FPC 24 side to the front sheet 2
Since the groove is recessed toward the second side and a part of the spacer sheet 52 is interposed between the slack absorbing space portion 31 and the front sheet 22 (in the present embodiment, the upper spacer sheet 53 is interposed), the spacer The function as the seat 52 can be maintained.

Furthermore, the polydome switch 5 of this embodiment
Since No. 1 is provided with the adhesive sheet 25 and the FPC 24 is provided with the external connecting means 34, it can be installed at a site according to the needs of the user or can be easily installed.

Furthermore, since the polydome switch 51 of this embodiment can be electrically connected to the outside through the edge connector terminal 38 (the same applies to the connector 61 described later), the installation can be further facilitated. can do.

In addition, according to the present embodiment, if the spacer sheet 52 is thickened and the necessary stroke dimension is secured within a range that does not impair the flexibility, the stroke of the protrusion 27 can be increased (in other words, in other words). For example, depending on the thickness of the spacer sheet 52, the stroke dimension of the protrusion 27 at the time of switch operation can be set to a required dimension).

Next, the polydome switch 21
A modification based on (51) will be described. FIG. 7 is a perspective view for explaining another example of the external connection means 34.
Further, FIG. 8 is a sectional view for explaining still another example of the external connecting means 34.

In FIG. 7, the external connection means 34 is provided with a plurality of edge connector terminals 38. However, as shown in FIG. 7, the plurality of edge connector terminals 38 are replaced by virtual lines. Connector 61
May be provided at the tip of the connection circuit section 37. In this way, the configuration of the external connection means 34 can be appropriately changed according to the form of the connection partner.

In FIG. 8, the external connection means 34 is provided with a wiring circuit portion 37 having an appropriate length, but as shown in FIG. 8, only a plurality of edge connector terminals 38 may be provided. I shall. The plurality of edge connector terminals 38 may be provided so as to be bent so as to be orthogonal to the circuit body 33, or may be provided so as to be provided along the adhesive fixing surface of the adhesive sheet 25. Thus, the structure of the external connection means 34 is as follows.
It can be changed as appropriate according to the form of the connection partner.

In addition, it goes without saying that the present invention can be modified in various ways without departing from the spirit of the present invention. That is, the spacer sheet 52 is the upper spacer sheet 5
3 and the lower layer spacer sheet 54, the lower layer spacer sheet 54 may be replaced by the spacer sheet 23. Further, the poly dome switch (dome switch) may have a configuration like the other configuration example of FIG. 9.

In FIG. 9, a polydome switch denoted by reference numeral 141 (corresponding to the dome switch described in the claims) is a front sheet 142, a spacer sheet 143, a membrane sheet 144, and the slack absorbing member, for example. A second spacer sheet (spacer sheet) 145 having a space 31 (see FIG. 2), and an FPC 146.
And a plurality of adhesive layers 147 and an adhesive sheet 148, and the movable contact 149 and the fixed contact 15 are provided.
It is configured with 0.

The front sheet 142 is a flexible sheet member made of, for example, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), which is made of a synthetic resin. Has a protruding portion 151.
The protruding portion 151 is formed in a dome shape that protrudes to the outer surface (front surface) side of the front sheet 142 and can be inverted to the inner surface (rear surface) side. Such a front sheet 142 is
Since it is made of the above material, it is originally transparent, and in the present embodiment, the above-mentioned characters and the like are printed on the inner surface or outer surface of the front sheet 142.

The spacer sheet 143 is a flexible resin sheet member made of, for example, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), and is used to prevent deformation of the front sheet 142 and to prevent protrusions 151. It is provided in order to realize air bleeding at the time of reversing and to secure the stroke size of the protrusion 151. The known adhesive layers 147 are provided on the front and back surfaces of the spacer sheet 143, respectively, so that the front sheet 142 and the membrane sheet 144 can be fixed to the front and back surfaces, respectively.

Such a spacer sheet 143 has through holes 152 formed corresponding to the positions of the protrusions 151.
And an air escape portion (not shown). Through hole 1
52 is formed to have a diameter larger than the diameter of the protrusion 151 (may be the same as the diameter of the protrusion 151). The inverted protrusion 151 is inserted into the through hole 152.

The membrane sheet 144 is a flexible thin sheet member made of a synthetic resin such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), and has a rear surface at a predetermined position with respect to the FPC 146. Movable contact 1
49 are provided.

The second spacer sheet 145 is a flexible resin sheet member made of, for example, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), which prevents deformation of the membrane sheet 144 and the membrane sheet 144. It is provided to secure the stroke size of. Adhesive layers 147 are provided on the front and back surfaces of the second spacer sheet 145, respectively.
The PC 146 and the PC 146 can be fixed to the front and back surfaces, respectively. Such a second spacer sheet 14
Reference numeral 5 has a through hole 153 formed corresponding to the position of the contact 149 on the movable side, and the slack absorbing space portion 31 (see FIG. 2) not shown here. The slack absorption space portion 31 (not shown) (see FIG. 2) is arranged and formed so as to correspond to the bending position of the polydome switch 141. The slack absorbing space portion 31 may be formed not only over the second spacer sheet 145 but also over the spacer sheet 143 above the second spacer sheet 145.

The FPC 146 is a circuit body,
A circuit body 154 having a switch circuit (not shown) arranged in a desired pattern and an external connecting means (not shown) used for electrical connection with the outside are provided. On the side of the second spacer sheet 145 of the circuit body 154, the contact 15 on the fixed side in contact with the contact 149 on the movable side
0 is provided (in addition, a light emitting element such as an LED may be provided. When the light emitting element is provided, for example, the spacer sheet 143 and the membrane sheet 1 are provided.
44, and a housing portion for the light emitting element that extends over the second spacer sheet 145 and has a light transmissive function). The external connection means (not shown) includes a wire connection circuit portion that is drawn out from the circuit body main body 154, and an edge connector terminal, for example, provided at the tip of the wire connection circuit portion.

The pressure-sensitive adhesive sheet 148 is the same as the pressure-sensitive adhesive sheet 25 (see FIG. 1) described above, has an adhesive fixing surface, and has a base plate 1 as a member to be attached.
The base plate 155 has a horizontal surface as shown in the drawing and an inclined surface not shown in the drawing.

In the above structure, the polydome switch 141 is assembled as follows. First, the front sheet 1
42 is adhesively fixed to the surface of the spacer sheet 143. Then, the membrane sheet 144 is attached to the second spacer sheet 1
The FPC 146 is adhesively fixed to the front surface of the second spacer sheet 145 while being fixed to the front surface of the second spacer sheet 145. Subsequently, the membrane sheet 1 is formed on the back surface of the spacer sheet 143.
44, the second spacer sheet 145, and the switch portion composed of the FPC 146 are adhesively fixed, and these are connected to the FPC.
Assembling is performed by adhesively fixing the adhesive sheet 148 to the circuit body attachment surface of the adhesive sheet 148. The thus-assembled flexible polydome switch 141 is similarly attached to the base plate 155 and acts as follows (operation drawings are omitted).

In the state where no load is applied to the protrusion 151 before the switch operation, the shape is maintained by the shape retention of the protrusion 151 itself. Then, when the switch operation is performed and the protruding portion 151 is pressed in the arrow direction by the finger 156 of the person who operates the switch (a pressing operation of applying a load downward), the protruding portion 151 receives the load due to the pressing of the finger 156. While resisting, it buckles and reverses at a certain load (at this time, a click feeling occurs).

When the protrusion 151 buckles or reverses, the downward load is reduced, and the pressing of the protrusion 151 proceeds smoothly. The inverted protrusion 151 is further pushed and inserted into the through hole 152 of the spacer sheet 143 to press the membrane sheet 144. When the membrane sheet 144 is pressed, it bends, and the contact 149 on the movable side provided on the membrane sheet 144 becomes the second spacer sheet 1.
The contact 150 on the fixed side of the FPC 146 is contacted via the through hole 153 of 45.

As a result, the switch circuit (not shown) of the FPC 146 becomes conductive, and the polydome switch 1
41 is turned on. On the other hand, when the finger 156 is released and the downward load is released, the membrane sheet 144 and the protrusion 151 return to the original state. Then, along with this, the conduction state is released, and the polydome switch 141 is turned off.
F will be done.

[0087]

As described above, according to the present invention described in claim 1, it is possible to provide the dome switch capable of absorbing the slack generated in the circuit body. That is, since the slack absorption space portion is formed in the spacer sheet, the slack absorption circuit portion can absorb the slack in the circuit body that occurs during bending. As a result, it is possible to eliminate factors that hinder the installation, aesthetics, and functions of the dome switch.

According to the present invention described in claim 2,
Since a part of the spacer sheet is always interposed between the slack absorbing space portion and the front sheet, there is an effect that the function as the spacer sheet can be maintained in addition to the effect of the invention of claim 1.

According to the present invention described in claim 3,
In addition to the effect of the invention of claim 1 or claim 2, since the circuit body has an external connection means, it can be installed at a site according to the needs of the user. It produces an effect (the installation range can be further expanded). Further, there is an effect that it can be easily attached (can be easily installed).

According to the present invention described in claim 4,
Since electrical connection with the outside can be performed via the edge connector terminal or the connector, there is an effect that installation can be further facilitated in addition to the effect of the invention of claim 3.

According to the present invention described in claim 5,
Since the electric connection with the outside can be made within the range of the length of the wired circuit portion drawn out from the circuit body, the installation range can be further expanded in addition to the effect of the invention of claim 4. It has the effect of being able to.

According to the present invention described in claim 6,
In addition to the effects of the invention according to any one of claims 3 to 5,
It is possible to protect the adhesive fixing surface and to carry the switch.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a dome switch according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the dome switch of the first embodiment.

FIG. 3 is an enlarged cross-sectional view showing an installed state of the dome switch of the first embodiment.

FIG. 4 is an exploded perspective view showing a second embodiment of the dome switch according to the present invention.

FIG. 5 is an enlarged cross-sectional view of the dome switch of the second embodiment.

FIG. 6 is an enlarged cross-sectional view showing an installed state of the dome switch of the second embodiment.

FIG. 7 is a perspective view for explaining another example of the external connection means.

FIG. 8 is a cross-sectional view for explaining still another example of the external connecting means.

FIG. 9 is a cross-sectional view showing another configuration example of the dome switch according to the present invention.

FIG. 10 is an enlarged cross-sectional view of a conventional dome switch.

[Explanation of symbols]

21 Poly Dome Switch (Dome Switch) 22 front sheet 23 Spacer sheet 24 FPC (circuit body) 25 Adhesive sheet 26 Attached member 27 Projection 28 electrodes (movable contact) 29 through holes 30 Air escape section 31 Slack absorbing space 32 switch circuit 33 Circuit body 34 External connection means 35 contacts (fixed side contacts) 36, 39 Air escape holes 37 Wiring circuit section 38 Edge connector terminal 40 Horizontal 41 slope 42 Slack 51 Poly Dome Switch (Dome Switch) 52 Spacer sheet 53 Upper layer spacer sheet 54 Lower layer spacer sheet 55 split lower layer spacer sheet 61 connector 141 Poly Dome Switch (Dome Switch) 142 front sheet 143 spacer sheet 144 membrane sheet 145 Second spacer sheet (spacer sheet) 146 FPC (circuit body) 147 adhesive layer 148 Adhesive sheet 149 Movable contact 150 contacts on the fixed side 151 protrusion 152,153 through holes 154 Circuit body 155 base plate 156 fingers

Continued front page    F-term (reference) 5G006 AA01 AA02 AB25 AC01 AC03                       AC05 AC07 AZ01 BA01 BA02                       BB03 BC01 CD03 CD04 DB03                       DD01 FB01 FB04 FB14 FB21                       FB22 FB25 FB29 FB32 FD02                       JA01 JB03 JC01 JD01 JE03                       JF02 LG02                 5G023 AA12                 5G052 AA12 BB01 HA01 HA02 JA02                       JA08 JB02 JB05

Claims (6)

[Claims] 1. A dome switch that can be bent in a mountain-folding direction at a predetermined position, the front sheet having a dome-shaped projecting portion projecting to the outer surface side and reversible to the inner surface side; A movable side contact that is displaced along with the movable side contact, a fixed side contact that faces the movable side contact, and a circuit body having the fixed side contact, and between the front sheet and the circuit body. And one or a plurality of spacer sheets having a through hole for ensuring contact between the movable-side contact and the fixed-side contact, and corresponding to the predetermined position of the spacer sheet. In part,
A dome switch characterized in that a slack absorbing space portion for absorbing the slack of the circuit body that occurs during bending is formed. 2. The dome switch according to claim 1, wherein a part of the spacer sheet is always interposed between the slack absorbing space portion and the front sheet. 3. The dome switch according to claim 1, further comprising an adhesive sheet having a circuit body mounting surface for the circuit body on one side and an adhesive fixing surface for a member to be mounted on the other side, and A dome switch, wherein the circuit body is provided with an external connection means used for electrical connection to the outside. 4. The dome switch according to claim 3, wherein the external connection means has an edge connector terminal or a connector. 5. The dome switch according to claim 4, wherein the external connection means further includes a wire connection circuit portion that is drawn out from the circuit body body. 6. The dome switch according to claim 3, wherein the adhesive sheet has release paper on the adhesive fixing surface.