JP2002170454A - Dome switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dome switch where a projecting part can be made high in stroke. SOLUTION: In the device, a surface sheet 22 with dome shaped projecting parts 27 which can be inverted inside as well as being projected outside and provided with electrodes on the inner surfaces, FPC 24 as a circuit provided with contact points 32 where the electrodes are brought into contact after the projecting parts 27 are inverted inside and a spacer sheet 23 for preventing deformation of the surface sheet 22 that is provided with through holes 29 to secure contact between the electrodes and the contact points 32 as well as intervening between the surface sheet 22 and the FPC 24 are provided. Then, the spacer sheet 23 is made to function as a member to secure the stroke of the projecting parts 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dome switch having a front sheet having a dome-shaped protrusion, a spacer sheet, and a circuit body, and more particularly to a dome switch characterized by a spacer sheet.

[0002]

2. Description of the Related Art FIG. 12 is an exploded perspective view of a conventional polydome switch (dome switch), FIG. 13 is a sectional view of a main part before a switch is operated, and FIG. . Referring to FIG. 12, a conventional polydome switch (dome switch) used for household appliances
1 includes a front sheet 2, a spacer sheet 3, an FPC 4, and an adhesive sheet 5, and is fixed to a plate 6 as a member to be attached via the adhesive sheet 5.

The front sheet 2 has a plurality of dome-shaped protrusions 7 projecting outward and reversible toward the inner surface.
Are formed. An electrode 8 (see FIG. 13) for the FPC 4 is provided on the inner surface of the protrusion 7.

[0004] The spacer sheet 3 is a thin sheet member, and is provided to prevent deformation of the front sheet 2. In addition, the spacer sheet 3 is provided with an adhesive layer on the front and back surfaces thereof, so that the front sheet 2 and the FPC 4 can be fixed. A plurality of through holes 9 are formed in the spacer sheet 3 at positions corresponding to the protrusions 7. A slit-shaped air escape portion 10 is formed between the through holes 9.

[0005] The FPC 4 is a circuit body having a plurality of circuits arranged in a desired pattern. A plurality of contacts 11 for contacting the electrodes 8 (see FIG. 13) are provided on the spacer sheet 3 side. I have. Further, the FPC 4 is adhered and fixed to the pressure-sensitive adhesive sheet 5. The adhesive sheet 5 also has a function as a reinforcing member.

In the above configuration, as shown in FIG. 14, when the protruding portion 7 is pressed down and the switch is operated, the protruding portion 7 is inverted toward the FPC 4 and the electrode 8 contacts the contact 11 as shown in FIG. The circuit acts to conduct. Incidentally, since the polydome switch 1 is a switch used for household appliances, the switch operation is usually performed visually, and the stroke dimension (amount) of the protrusion 7 at the time of the switch operation is slightly secured. Was enough.

[0007]

However, when the above-mentioned conventional polydome switch 1 is used as a switch of a device mounted on a vehicle such as an automobile, there are the following problems. That is, since the switch operation is frequently performed during driving, the switch operation as described above cannot be naturally performed in terms of safety in view of safety. Therefore, the stroke size of the protruding portion 7 must be sufficiently ensured, and the structure must be such that the switch operation can be surely confirmed without visual inspection. However, there is a limit in manufacturing to secure the stroke size by increasing the protruding height of the protruding portion 7, so that sufficient measures could not be taken.

The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a dome switch capable of increasing the stroke of a projection.

[0009]

According to a first aspect of the present invention, there is provided a dome switch according to the first aspect of the present invention, wherein the dome switch protrudes outward and is reversible inward and has an electrode provided on the inner surface. A front sheet having a dome-shaped protruding portion, a circuit body having a contact with which the electrode of the protruding portion turned to the inner surface side contacts, and an electrode interposed between the front sheet and the circuit body. And a spacer sheet for preventing deformation of the front sheet formed with a through hole for ensuring contact with the contact point, wherein the spacer sheet secures a stroke dimension of the protrusion. It is also characterized by functioning as a member for performing

A dome switch according to a second aspect of the present invention is the dome switch according to the first aspect, wherein the spacer sheet is constituted by a plurality of layers.

According to a third aspect of the present invention, there is provided a dome switch according to the first aspect, wherein the spacer sheet is constituted by a plurality of layers, and the uppermost spacer sheet on the front sheet side is finely adjusted to the stroke dimension. It is characterized in that it is formed thinner than one or a plurality of lower spacer sheets for adjustment.

A dome switch according to a fourth aspect of the present invention is the dome switch according to the first aspect, wherein the spacer sheet is constituted by a plurality of layers, and one or more spacer sheets other than the uppermost spacer sheet on the front sheet side are provided. An air escape portion communicating with the through hole is formed in the lower spacer sheet.

A dome switch according to a fifth aspect of the present invention is the dome switch according to the first aspect, wherein the spacer sheet is composed of a plurality of layers, and the diameter of the through hole of the uppermost layer spacer sheet on the front sheet side. Is formed so as to be larger or equal to the diameter of the projecting portion, and the diameter of the through hole of one or a plurality of lower layer spacer sheets is larger or equal to the diameter of the through hole of the uppermost layer spacer sheet. It is characterized in that it is formed so that

According to the first aspect of the present invention,
When the switch is operated, after the protrusion is pressed and the protrusion is inverted, the electrode on the inner surface of the protrusion contacts the contact point of the circuit body via the through hole of the spacer sheet. The spacer sheet functions not only as a member for preventing deformation of the front sheet but also as a member for securing a stroke size of the protruding portion. Therefore, in order to increase the stroke of the protrusion, the thickness of the spacer sheet may be increased as long as the protrusion can return to the original state. As a result, the depth of the through hole is increased, and the stroke size of the protruding portion can be increased. In addition, deformation of the front sheet is naturally prevented. The spacer sheet has an important function for maximizing the stroke of the protrusion.

According to the second aspect of the present invention,
The dome switch has a spacer sheet composed of a plurality of layers. Thus, for example, the thickness can be changed depending on the number of layers, and the adjustment of the stroke size of the protruding portion is facilitated. In addition, it is possible to provide more flexibility than a single layer (the same applies to claims 3 to 5).

According to the third aspect of the present invention,
The dome switch has a spacer sheet composed of a plurality of layers. Thus, for example, the thickness can be changed depending on the number of layers, and the adjustment of the stroke size of the protruding portion is facilitated. Further, a dome switch is formed in which the uppermost spacer sheet on the front sheet side is formed thinner than one or a plurality of lower spacer sheets. Thereby, fine adjustment of the stroke size of the protruding portion becomes possible.

According to the present invention as set forth in claim 4,
The dome switch has a spacer sheet composed of a plurality of layers. Thus, for example, the thickness can be changed depending on the number of layers, and the adjustment of the stroke size of the protruding portion is facilitated. Further, the dome switch has no air escape portion in the uppermost spacer sheet on the front sheet side. As a result, there is no edge generated by the air escape portion on the front sheet side, and protection when the protruding portion is reversed is enabled. In addition, it is possible to minimize the deformation of the front sheet around the through hole when the protruding portion is reversed. In addition, since one or a plurality of lower layer spacer sheets are provided with an air escape portion, a click feeling at the time of a switch operation is maintained.

According to the present invention as set forth in claim 5,
The dome switch has a spacer sheet composed of a plurality of layers. Thus, for example, the thickness can be changed depending on the number of layers, and the adjustment of the stroke size of the protruding portion is facilitated. Further, the dome switch is such that the diameter of each through hole of the spacer sheet is regulated. This makes it possible to minimize deformation of the front sheet around the through hole when the protruding portion is inverted.

[0019]

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. FIG.
FIG. 3 is a cross-sectional view of a main part of the first embodiment before a switch is operated, and FIG. 3 is a cross-sectional view of a main part of the first embodiment when the switch is operated.

In FIG. 1, a polydome switch indicated by reference numeral 21 (corresponding to a dome switch described in the claims) has a high stroke required for a switch of a device mounted on a vehicle such as an automobile. And a front sheet 22, a spacer sheet 23, and an FP
C24 and an adhesive sheet 25 are provided. The polydome switch 21 is fixed to a plate 26 as an example of a member to be mounted in the vehicle via an adhesive sheet 25. The plate 26 may be included in the configuration of the polydome switch 21 (if the plate is as illustrated, it may be included).

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

The front sheet 22 has a plurality of protrusions 27.
have. Each protruding portion 27 is formed in a dome shape that protrudes to the outer surface side and is reversible to the inner surface side. The FPC 24 is provided on the inner surface of each projection 27.
(See FIG. 2). The electrode 28 (see FIG. 2) is provided on the top of the inner surface.

The table sheet 22 will be described in more detail. The table sheet 22 is a sheet made of a synthetic resin made of, for example, polyethylene terephthalate (PET), and is hot pressed (a pressure is applied from the inner surface to the outer surface). And a plurality of dome-shaped protrusions 27 formed by applying the dome shape. In addition, each dome-shaped protrusion 2
The electrode 28 provided on the top of the inner surface of 7 is made of carbon or the like (in the case of the electrode 28 made of carbon, it is provided by printing).

The spacer sheet 23 is a synthetic resin thick sheet member made of, for example, polyethylene terephthalate (PET), and functions as a member for preventing deformation of the front sheet 22 as in the conventional example. have. The spacer sheet 23 also has a function not found in the related art, as a member for securing the stroke dimension of the protrusion 27. That is, the spacer sheet 2
3 is formed, for example, in a sheet shape having a thickness that is about half the dimension that allows the protrusion 27 to make a maximum stroke. In the present embodiment, the thickness of the front sheet 22 (excluding the height of the protruding portion 27) is 125 μm, and the dimension that allows the protruding portion 27 to make a maximum stroke is 1.5 mm (of which the height of the protruding portion 27 is 750 μm), and the thickness of the spacer sheet 23 is 750 μm.

The spacer sheet 23 will be described in more detail. The spacer sheet 23 has an adhesive layer (not shown) on the front and back surfaces.
The PC 24 and the PC 24 can be fixed to the front and back surfaces, respectively. Further, the spacer sheet 23 has a plurality of through holes 29 and a plurality of air escape portions 30.
The inverted projections 27 can be inserted, and the air existing on the inner surface side when the projections 27 are inverted can be appropriately released.

Each of the through holes 29 is formed in accordance with the position of the corresponding projection 27. In addition, each through hole 2
9 are each formed to have a diameter larger than the diameter of the corresponding protrusion 27 (see FIG. 2; protrusion 27).
May be the same as the diameter). Each of the air escape portions 30 has a slit shape, and
Are formed between the through holes 29 arranged in the longitudinal direction.
Further, each air release portion 30 is formed so as to communicate with the corresponding through hole 29.

The FPC 24 (FPC: Flexible Print Circuit) is a circuit body having a plurality of circuits 31 arranged in a desired pattern. The electrodes 28 (see FIG. 2) are provided on the spacer sheet 23 side. A plurality of contact points 32 that contact each other are provided. The FPC 24 has air release holes 33 communicating with the air release portion 30 of the spacer sheet 23. In this embodiment,
The thickness of the FPC 24 is 100 μm. The circuit body is not limited to the FPC (FPC 24).

The pressure-sensitive adhesive sheet 25 is formed so that the FPC 24 can be adhered and fixed. Also,
The adhesive sheet 25 is formed so as to be adhered and fixed to the plate 26. Further, the adhesive sheet 25 has a function as a reinforcing member. The adhesive sheet 25 communicates with the air release holes 33 of the FPC 24,
Similar air escape holes 34, 34 are formed. The air vent holes 34 communicate with air vents 35 formed in the plate 26.

In the above configuration, the polydome switch 21 is assembled as follows. First, the front sheet 22
To the surface of the spacer sheet 23, and
The FPC 24 is bonded and fixed to the back surface of the spacer sheet 23. Next, these are adhesively fixed to one surface of the adhesive sheet 25 from the FPC 24 side. Thus, the assembly is completed.

Next, the operation of the polydome switch 21 will be described with reference to FIGS.

In FIG. 2, when no load is applied to the protrusion 27 before the switch is operated, the protrusion 27
The shape is maintained by the shape retention property of itself.

In FIG. 3, when the switch is operated and the protruding portion 27 is depressed in the direction of the arrow (when a load is applied in the direction of the arrow), the protruding portion 27 resists the load in the direction of the arrow. It buckles and reverses at the load (at this time, a click feeling is generated). Then, the load in the direction of the arrow is reduced due to the buckling and inversion of the protruding portion 27, and the pressing of the protruding portion 27 proceeds smoothly. The inverted protrusion 27 is the spacer sheet 2
3, the electrode 28 provided on the protruding portion 27 contacts the contact 32 of the FPC 24 via the through hole 29 (see FIG. 1). Thereby, the circuit 31 (see FIG. 1)
Are turned on, and the polydome switch 21 is turned on. When the load in the direction of the arrow is released, the protruding portion 27 returns to the original state.

As described above, the polydome switch 21 of the present embodiment
Since the spacer sheet 23 functions not only as a member for preventing deformation of the front sheet 22 but also as a member for securing a stroke size of the protruding portion 27, the spacer sheet 23 as described above is used. If the required stroke size is secured by increasing the thickness of the
Can be increased in stroke. Note that, depending on the thickness of the spacer sheet 23, the protrusion 27 at the time of switch operation
It is needless to say that the stroke dimension can be set to a required dimension.

Next, a dome switch according to a second embodiment will be described with reference to FIG. FIG. 4 is an exploded perspective view showing a second embodiment of the dome switch according to the present invention. The same components as those of the polydome switch 21 described above are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 4, the polydome switch indicated by reference numeral 41 (corresponding to the dome switch described in the claims) is the same as the above-described polydome switch 21.
Similarly to (see FIG. 1), a high stroke required for a switch of a device mounted on a vehicle such as an automobile is realized, and the front sheet 22, the spacer sheet 42 and the F
It comprises a PC 24 and an adhesive sheet 25.
The polydome switch 41 is fixed to the plate 26 as an example of a member to be mounted in the vehicle via the adhesive sheet 25. As described above, the plate 26
May be included in the configuration of the polydome switch 41.

The spacer sheet 42 includes an upper spacer sheet 43 and a lower spacer sheet 44. That is, the spacer sheet 42 is composed of two layers. The spacer sheet 42 is formed of the front sheet 2 similarly to the spacer sheet 23 (see FIG. 1).
2 has a function as a member for preventing deformation and a function as a member for securing a stroke dimension of the protruding portion 27. The upper spacer sheet 43 and the lower spacer sheet 44 are both sheet members made of a synthetic resin made of, for example, polyethylene terephthalate (PET), and the upper spacer sheet 43 is formed thinner than the lower spacer sheet 44. That is, in this embodiment, the thickness of the upper spacer sheet 43 is 150 μm.
m, the thickness of the lower spacer sheet 44 is 300 μm, and the upper spacer sheet 43 functions as a sheet member for fine adjustment when securing the stroke size of the protrusion 27. The upper spacer sheet 43
Corresponds to the uppermost spacer sheet described in the claims.

The upper spacer sheet 43 has an adhesive layer (not shown) on the front and back surfaces, so that the front sheet 22 and the lower spacer sheet 44 can be fixed to the front and back surfaces, respectively. The upper spacer sheet 43 has a plurality of through holes 29 and a plurality of air escape portions 30.

The lower spacer sheet 44 has an adhesive layer (not shown) on the front and back surfaces, so that the upper spacer sheet 43 and the FPC 24 can be fixed to the front and back surfaces, respectively. The lower spacer sheet 4
4 is the same as the plurality of through holes 29 as in the upper spacer sheet 43.
(The diameter of the through hole 29 of the lower spacer sheet 44 is larger or equal to the diameter of the through hole 29 of the upper spacer sheet 43. The diameter is increased. If this is the case, the area for air release can be made large, and the click feeling will not be impaired).

When the upper spacer sheet 43 and the lower spacer sheet 44 are overlapped to form the spacer sheet 42, the upper spacer sheet 43 and the lower spacer sheet 44 are formed with the through holes 29 of the upper spacer sheet 43 and the lower spacer sheet 44, respectively. The air release portion 30 is configured to coincide with the air release portion 30.

In the above configuration, the polydome switch 41 is assembled as follows. First, the upper spacer sheet 43 and the lower spacer sheet 44 are bonded and fixed to form the spacer sheet 42. Next, the front sheet 22 is bonded and fixed to the surface of the spacer sheet 42 (actually, the upper spacer sheet 43), and the FPC 24 is fixed to the back surface of the spacer sheet 42 (actually, the lower spacer sheet 44).
Adhesively fixed. Subsequently, these are adhesively fixed to one surface of the adhesive sheet 25 from the FPC 24 side. Thus, the assembly is completed.

The operation of the polydome switch 41 is the same as the operation of the above-described polydome switch 21, and therefore the description thereof is omitted here (the stroke dimension of the protruding portion 27 secured by the spacer sheet 42 is reduced). They are just different).

As described above, in the polydome switch 41 according to the second embodiment, in addition to the function of the spacer sheet 42 as a member for preventing the deformation of the front sheet 22, the stroke of the protrusion 27 is ensured. Since it also functions as a member, the above-described polydome switch 21
Similarly to the above, the stroke of the protruding portion 27 can be increased. Further, the polydome switch 4 according to the second embodiment
1 is that, since the spacer sheet 42 is composed of the upper layer spacer sheet 43 and the lower layer spacer sheet 44, the spacer sheet 42 can have more flexibility than a single layer and can adjust the stroke dimension of the protrusion 27 to be secured. It can be easily performed (in other words, the stroke dimension of the protruding portion 27 to be ensured can be easily adjusted by selectively using the upper spacer sheet 43 and the lower spacer sheet 44 having different thicknesses or by increasing or decreasing the thickness. be able to). Further, in the polydome switch 41 of the second embodiment, since the upper spacer sheet 43 functions as a sheet member for fine adjustment when securing the stroke size of the protrusion 27, the stroke of the protrusion 27 The dimension can be easily fine-tuned (in other words, the stroke dimension of the protruding portion 27 can be easily fine-tuned by giving the thickness of the upper spacer sheet 43 variations and using them properly).

Next, a dome switch according to a third embodiment will be described with reference to FIG. FIG.
FIG. 9 is an exploded perspective view showing a third embodiment of the dome switch according to the present invention. The above-mentioned polydome switch 2
1 and the same components as those of the polydome switch 41 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 5, a polydome switch denoted by reference numeral 51 (corresponding to the dome switch described in the claims) is the same as the polydome switch 21 described above.
(See FIG. 1) and polydome switch 41 (see FIG. 4)
Similarly to the above, for example, a high stroke required for a switch of a device mounted on a vehicle such as an automobile is realized, and is configured to include a front sheet 22, a spacer sheet 52, an FPC 24, and an adhesive sheet 25. I have. The polydome switch 51 is fixed to the plate 26 as an example of a member to be mounted in the vehicle via the adhesive sheet 25. As described above, the plate 26 may be included in the configuration of the polydome switch 51.

The spacer sheet 52 comprises an upper spacer sheet 43 and lower spacer sheets 44,44. That is, the spacer sheet 52
It is composed of three layers. In addition, the spacer sheet 52
Similarly to the above-described spacer sheet 23 (see FIG. 1) and the spacer sheet 42 (see FIG. 4), the function as a member for preventing the deformation of the front sheet 22 and the function for securing the stroke dimension of the protruding portion 27 are provided. It has a function as a member. In the present embodiment, the thickness of the spacer sheet 52 is 750 μm in total for the three layers (the thickness is the same as that of the above-described spacer sheet 23. In other words, the protrusion 2)
7 is about half the thickness that allows the maximum stroke).

In the above configuration, the polydome switch 51 is assembled as follows. First, the upper spacer sheet 43 and the lower spacer sheets 44, 44 are bonded and fixed to form a spacer sheet 52. Next, Table sheet 2
2 is adhesively fixed to the front surface of the spacer sheet 52 (actually, the upper spacer sheet 43), and the FPC 24 is adhesively fixed to the back surface of the spacer sheet 52 (actually, the lowermost spacer sheet 44, which is the lowermost layer). Subsequently, these are adhesively fixed to one surface of the adhesive sheet 25 from the FPC 24 side. Thus, the assembly is completed.

The operation of the polydome switch 51 will now be described with reference to FIGS. FIG. 6 is a cross-sectional view of a main part of the third embodiment before a switch is operated, and FIG. 7 is a cross-sectional view of a main part of the third embodiment when the switch is operated.

In FIG. 6, when no load is applied to the protrusion 27 before the switch is operated, the protrusion 27
The shape is maintained by the shape retention property of itself.

In FIG. 7, when the switch is operated and the protruding portion 27 is depressed in the direction of the arrow (when a load is applied in the direction of the arrow), the protruding portion 27 is at a certain position while resisting the load in the direction of the arrow. It buckles and reverses at the load (at this time, a click feeling is generated). Then, the load in the direction of the arrow is reduced due to the buckling and inversion of the protruding portion 27, and the pressing of the protruding portion 27 proceeds smoothly. The inverted protrusion 27 is the spacer sheet 5
2 is inserted into the through hole 29 of each layer, and the electrode 28 provided on the protruding portion 27 contacts the contact point 32 (see FIG. 5) of the FPC 24 through the through hole 29 of each layer. This allows the circuit 31
(See FIG. 5) becomes conductive, and the polydome switch 5
1 is turned on. When the load in the direction of the arrow is released, the protruding portion 27 returns to the original state.

As described above, in the polydome switch 51 of the third embodiment, in addition to the function of the spacer sheet 52 as a member for preventing the deformation of the front sheet 22, the stroke of the protrusion 27 is ensured. Since it also functions as a member, the above-described polydome switch 21
Like the polydome switch 41, the stroke of the protruding portion 27 can be increased. The polydome switch 51 according to the third embodiment includes a spacer sheet 52
To the upper spacer sheet 43 and the lower spacer sheet 4
4 and 44, it is possible to provide more flexibility than a single layer, and it is possible to easily adjust the stroke dimension of the protruding portion 27 to be secured (in other words, to vary the thickness). It is possible to easily adjust the stroke dimension of the protruding portion 27 to be secured by using or increasing or decreasing the upper spacer sheet 43 and the lower spacer sheet 44 provided with (). Further, in the polydome switch 51 of the third embodiment, since the upper spacer sheet 43 functions as a sheet member for fine adjustment when securing the stroke dimension of the protrusion 27, the stroke of the protrusion 27 The dimension can be easily fine-tuned (in other words, the stroke dimension of the protruding portion 27 can be easily fine-tuned by giving the thickness of the upper spacer sheet 43 variations and using them properly).

Next, a dome switch according to a fourth embodiment will be described with reference to FIG. FIG.
FIG. 9 is an exploded perspective view showing a fourth embodiment of the dome switch according to the present invention. The above-mentioned polydome switch 2
1, the same components as those of the polydome switch 41 and the polydome switch 51 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 8, the polydome switch indicated by the reference numeral 61 (corresponding to the dome switch described in the claims) is the same as the polydome switch 21 described above.
(See FIG. 1), polydome switch 41 (see FIG. 4),
Similarly to the polydome switch 51 (see FIG. 5), a high stroke required for a switch of a device mounted on a vehicle such as an automobile is realized.
2, spacer sheet 62, FPC 24, and adhesive sheet 25
It is comprised including. The polydome switch 61 is fixed to the plate 26 as an example of a member to be mounted in the vehicle via the adhesive sheet 25.
As described above, the plate 26 is connected to the polydome switch 61.
May be included in the configuration.

The spacer sheet 62 includes an upper spacer sheet 63 and lower spacer sheets 44,44. That is, the spacer sheet 62
It is composed of three layers. Also, the spacer sheet 62
Like the spacer sheet 23 (see FIG. 1), the spacer sheet 42 (see FIG. 4), and the spacer sheet 52 (see FIG. 5), the function as a member for preventing the deformation of the front sheet 22 and the protrusion It has a function as a member for securing the stroke dimension of the portion 27. In this embodiment, the thickness of the spacer sheet 62 is 7
The thickness is 50 μm (the thickness is the same as that of the spacer sheet 23 described above. In other words, the thickness is approximately half the dimension that allows the protruding portion 27 to perform the maximum stroke).

The upper spacer sheet 63 is a synthetic resin sheet member made of, for example, polyethylene terephthalate (PET). The upper spacer sheet 63 is formed thinner than the lower spacer sheet 44.
That is, in the present embodiment, the thickness of the upper spacer sheet 63 is 150 μm. The upper spacer sheet 63 functions as a sheet member for fine adjustment when securing the stroke size of the protruding portion 27. The upper spacer sheet 63 corresponds to the uppermost spacer sheet described in the claims.

The upper spacer sheet 63 has an adhesive layer (not shown) on the front and back surfaces, so that the front sheet 22 and the lower spacer sheet 44 can be fixed to the front and back surfaces, respectively. The upper spacer sheet 63 has a plurality of through holes 64. In addition, the through hole 6
Reference numeral 4 corresponds to the through hole described in the claims, similarly to the above-described through hole 29.

Each through hole 64 is formed in accordance with the position of the corresponding protruding portion 27. In addition, each through hole 6
4 is formed so as to be larger or equal to the diameter φB of the protrusion 27 (φA ≧ φ
B). In addition, in such a dimensional relationship, by setting them on the same side, it is possible to minimize deformation of the front sheet 22 around the through hole 64 when the protruding portion 27 is inverted. Further, the diameter φA of each through hole 64 is formed so as to be smaller or equal to the diameter φC of each through hole 29 of the lower spacer sheets 44, 44. In other words, the diameter φC of each through hole 29 of the lower spacer sheets 44, 44 is formed so as to be larger or equal to the diameter φA of each through hole 64 (φC ≧ φA).
In addition, in such a dimensional relationship, if it is set to the larger side, the lower spacer sheet 44
Even if the air release portion 30 is not formed as described above, the plurality of air release portions 30 of the lower spacer sheet 44 can provide a sufficient area for air release (the click feeling is not impaired). ). Further, since the upper spacer sheet 63 does not have the air release portion 30 unlike the lower spacer sheet 44, the edge generated by the air release portion 30 is eliminated, and the front sheet 22 can be protected when the projecting portion 27 is inverted. Become.

In the above configuration, the polydome switch 61 is assembled as follows. First, the upper spacer sheet 63 and the lower spacer sheets 44, 44 are bonded and fixed to form the spacer sheet 62. Next, Table sheet 2
2 is adhesively fixed to the front surface of the spacer sheet 62 (actually, the upper spacer sheet 63), and the FPC 24 is adhesively fixed to the back surface of the spacer sheet 62 (actually, the lower spacer sheet 44, which is the lowermost layer). Subsequently, these are adhesively fixed to one surface of the adhesive sheet 25 from the FPC 24 side. Thus, the assembly is completed.

The operation of the polydome switch 61 will now be described with reference to FIGS. FIG. 9 is a cross-sectional view of a main part of the fourth embodiment before a switch is operated, and FIG. 10 is a cross-sectional view of a main part of the fourth embodiment when the switch is operated.

In FIG. 9, when no load is applied to the protrusion 27 before the switch is operated, the protrusion 27
The shape is maintained by the shape retention property of itself.

In FIG. 10, a switch operation is performed,
When the protruding portion 27 is pressed down in the direction of the arrow (when a load is applied in the direction of the arrow), the protruding portion 27 buckles and reverses at a certain load while resisting the load in the direction of the arrow (at this time, Click feeling). Then, the load in the direction of the arrow is reduced due to the buckling and inversion of the protruding portion 27, and the pressing of the protruding portion 27 proceeds smoothly. The inverted protrusion 27 is the spacer sheet 6
The electrode 28 which is inserted into the through hole 64 and the through hole 29 of each layer of the second layer and which is provided on the protruding portion 27 contacts the contact 32 (see FIG. 8) of the FPC 24 through the through hole 64 and the through hole 29 of each layer. As a result, the circuit 31 (see FIG. 8) becomes conductive, and the polydome switch 61 is turned on. When the load in the direction of the arrow is released, the protruding portion 27 returns to the original state.

As described above, in the polydome switch 61 of the fourth embodiment, in addition to the function of the spacer sheet 62 as a member for preventing the deformation of the front sheet 22, the stroke of the protrusion 27 is ensured. Since it also functions as a member, the above-described polydome switch 2
1, similarly to the polydome switch 41 and the polydome switch 51, it is possible to increase the stroke of the protrusion 27. Further, the polydome switch 61 of the fourth embodiment is different from the polydome switch 61 in that the spacer sheet 62 is
3 and the lower spacer sheets 44, 44, it is possible to have more flexibility than a single layer, and it is possible to easily adjust the stroke dimension of the protrusion 27 to be secured (in other words, For example, it is possible to easily adjust the stroke dimension of the protruding portion 27 to be ensured by properly using or increasing or decreasing the upper spacer sheet 63 and the lower spacer sheet 44 having variations in thickness). Further, in the polydome switch 61 of the fourth embodiment, since the upper spacer sheet 63 functions as a sheet member for fine adjustment when securing the stroke dimension of the protrusion 27, the stroke of the protrusion 27 The size can be easily finely adjusted (in other words, the stroke size of the protruding portion 27 can be easily finely adjusted by giving the thickness of the upper spacer sheet 63 variations and using them properly). Furthermore, the polydome switch 61 of the fourth embodiment
Since the upper spacer sheet 63 is used, the above-described various advantages such as minimizing the deformation of the front sheet 22 around the through hole 64 when the projecting portion 27 is inverted can be obtained.

Next, a specific example of mounting the dome switch will be described with reference to FIG. FIG.
FIG. 3 is an exploded perspective view showing a specific example of mounting a dome switch.

In FIG. 11, reference numeral 71 denotes a switch unit of a vehicle having a plurality of knob switches and a polydome switch. The switch unit 71
Is a bezel 73 having a plurality of switch knobs 72, a rubber contact 74, an FPC 76 as a circuit having a plurality of contacts 75, a front sheet 78 having dome-shaped protrusions 77, 77, and a front sheet 78 thereof. And a lower case 80 with which the bezel 73 engages, and is provided near the driver's seat side door and the center console. In such a switch unit 71, the polydome switch 8 is formed by the front sheet 78, the spacer sheet 79, and a part of the FPC 76.
1 (corresponding to the dome switch described in the claims)
, And is responsible for a part of the switches of the switch unit 71.
Needless to say, it is also possible to configure a polydome switch such as 1.

In addition, it goes without saying that the present invention can be variously modified and implemented without departing from the gist of the present invention. That is, for example, the spacer sheet may be composed of four or more layers. In addition, the number of protrusions and the like is not limited to the above.

It should be noted that the present invention is not limited to being applied to a switch of a device mounted on a vehicle such as an automobile or a switch unit of a vehicle. The switch is not limited to the above as long as it is a switch of a device or the like that requires a high stroke. That is, it is naturally applicable to a switch used for household appliances, a switch of a manufacturing apparatus, and the like.

[0066]

As described above, according to the first aspect of the present invention, it is possible to maximize the stroke of the projection. Therefore, the dome switch of the present invention has an effect that the stroke of the protruding portion can be increased.

According to the second aspect of the present invention,
Along with increasing the stroke of the protruding part,
There is an effect that adjustment of the stroke dimension of the protruding portion can be facilitated. In addition, there is an effect that the spacer sheet can have more flexibility than a single layer (the same applies to claims 3 to 5).

According to the third aspect of the present invention,
Along with increasing the stroke of the protruding part,
There is an effect that adjustment of the stroke dimension of the protruding portion can be facilitated. Also, there is an effect that the stroke dimension of the protrusion can be easily finely adjusted.

According to the fourth aspect of the present invention,
Along with increasing the stroke of the protruding part,
There is an effect that adjustment of the stroke dimension of the protruding portion can be facilitated. Also, there is an effect that the protruding portion can be inverted without damage. Furthermore, the effect that the deformation of the front sheet around the through hole when the protruding portion is reversed can be minimized is also exerted.

According to the fifth aspect of the present invention,
Along with increasing the stroke of the protruding part,
There is an effect that adjustment of the stroke dimension of the protruding portion can be facilitated. Further, there is an effect that the deformation of the front sheet around the through hole when the protruding portion is reversed can be minimized.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of a main part before a switch operation according to the first embodiment.

FIG. 3 is a cross-sectional view of a main part when a switch is operated according to 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 exploded perspective view showing a third embodiment of the dome switch according to the present invention.

FIG. 6 is a sectional view of a main part before a switch operation according to a third embodiment.

FIG. 7 is a sectional view of a main part when a switch is operated according to a third embodiment.

FIG. 8 is an exploded perspective view showing a fourth embodiment of the dome switch according to the present invention.

FIG. 9 is a sectional view of a main part of a fourth embodiment before a switch is operated.

FIG. 10 is a sectional view of a main part when a switch is operated according to a fourth embodiment.

FIG. 11 is an exploded perspective view showing a specific mounting example of the dome switch.

FIG. 12 is an exploded perspective view of a conventional polydome switch (dome switch).

FIG. 13 is a sectional view of a main part before a switch is operated.

FIG. 14 is a sectional view of a main part when a switch is operated.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 21 Polydome switch (dome switch) 22 Front sheet 23 Spacer sheet 24 FPC (circuit body) 25 Adhesive sheet 26 Plate 27 Projection part 28 Electrode 29 Through hole 30, 35 Air escape part 31 Circuit 32 Contact point 33, 34 Air escape hole 41 , 51, 61 Polydome switch (dome switch) 42, 52, 62 Spacer sheet 43, 63 Upper layer spacer sheet (Uppermost layer spacer sheet) 44 Lower layer spacer sheet 64 Through hole 71 Switch unit 76 FPC (circuit) 77 Projection 78 Front sheet 79 Spacer sheet 81 Polydome switch (dome switch)

Claims (5)

[Claims] 1. A front sheet having a dome-shaped protrusion that protrudes to the outside and is reversible to the inside and has an electrode provided on the inside, and the electrode of the protrusion that is reversed to the inside And a circuit body having a contact with which the contact is made, for preventing deformation of the front sheet, which is interposed between the front sheet and the circuit body and has a through hole formed for ensuring contact between the electrode and the contact. A dome switch, comprising: a spacer sheet; and wherein the spacer sheet also functions as a member for securing a stroke dimension of the protrusion. 2. The dome switch according to claim 1, wherein said spacer sheet is composed of a plurality of layers. 3. The dome switch according to claim 1, wherein the spacer sheet is composed of a plurality of layers, and the uppermost spacer sheet on the front sheet side is used for fine adjustment with respect to the stroke dimension. A dome switch characterized by being formed thinner. 4. The dome switch according to claim 1, wherein the spacer sheet is composed of a plurality of layers, and communicates with the through hole with one or a plurality of lower spacer sheets other than the uppermost spacer sheet on the front sheet side. A dome switch characterized by forming an air escape part. 5. The dome switch according to claim 1, wherein the spacer sheet is constituted by a plurality of layers, and the diameter of the through hole of the uppermost spacer sheet on the front sheet side is larger than the diameter of the protrusion. Or the diameter of the through hole of one or a plurality of lower layer spacer sheets is formed to be larger or equal to the diameter of the through hole of the uppermost layer spacer sheet. Dome switch.