Flat switch

A flat switch is provided that prevents the flat switch from protruding and thereby causing a poor appearance even in a case where it is required to install a switch box so that an end part on an opening side of the switch box is not positioned on a predetermined distance or deeper side with respect to an appearance surface that is a surface of a wall. A flat switch (1) of the present invention is a flat switch (1) that is installed in a switch box (100) having a bottom part (101) and a vertical wall part (102) which is provided along an outer periphery of the bottom part (101). The switch box (100) is installed so that, with respect to an appearance surface that is a front surface of a wall, a peripheral edge part (102A) is not positioned on a predetermined distance or deeper side in a depth direction of the wall from the appearance surface. The flat switch (1) includes a sensor unit (20) whose thickest part in a direction from the peripheral edge part (102A) of the switch box (100) to the bottom part (101) is thicker than a predetermined distance in a state of being installed in the switch box and whose outer shape is smaller than an inner shape of the peripheral edge part (102A) of the switch box (100).

TECHNICAL FIELD

The present invention relates to a flat switch.

BACKGROUND ART

Patent Literature 1 discloses a flat switch that has a sensor unit of an electrostatic capacitance type and is capable of, for example, being installed so as not to protrude from an exterior wall.

DOCUMENT LIST

Patent Literature

Patent Literature 1: Japanese Patent Application Publication No. 2016-162707

SUMMARY OF INVENTION

Technical Problem

In Japan, installation of a switch box is prescribed with reference to a rear surface of a wall. The thickness of the wall itself is equal to or more than the thickness of a sensor unit that is a switch part of a flat switch and therefore, even if the sensor unit is provided on the switch box, the sensor unit can be arranged so as not to protrude from the wall.

On the other hand, in the U.S., in order to perform a flame retardant test conforming to UL standards, it is necessary to install a switch box in compliance with the standard for electrical wiring and electrical installation of equipment called NEC (National Electrical Code) and it is required to install the switch box so that an end part on an opening side of the switch box is not positioned on a predetermined distance (specifically, 6.4 mm) or deeper side with respect to an appearance surface that is a front surface of a wall.

Therefore, in a case where the sensor unit is provided on the end part on the opening side of the switch box, for example, even a sensor unit of a relatively thin type has a thickness of around 9 mm and therefore, the sensor unit itself protrudes from the appearance surface, resulting in a state in which a flat switch is installed with a poor appearance.

The present invention has been made in view of the above and it is an object of the present invention to provide a flat switch that prevents the flat switch from protruding and thereby causing a poor appearance even in a case where it is required to install a switch box so that an end part on an opening side of the switch box is not positioned on a predetermined distance or deeper side with respect to an appearance surface that is a front surface of a wall.

Solution to Problem

The present invention is grasped by the following configuration to achieve the above purpose.

(1) A flat switch of the present invention is a flat switch to be installed in a switch box having a bottom part and a vertical wall part, the vertical wall part being provided along an outer periphery of the bottom part. The switch box is installed so that, with respect to the appearance surface that is the front surface of a wall, a peripheral edge part of the vertical wall part that is an end part on an opening side of the switch box is not positioned on a predetermined distance or deeper side in a depth direction of the wall from the appearance surface. The flat switch includes a sensor unit whose thickest part in a direction from the peripheral edge part of the switch box to the bottom part is thicker than the predetermined distance in a state of being installed in the switch box but whose outer shape is smaller than an inner shape of the peripheral edge part of the switch box.
(2) In the above configuration (1), an attaching plate that is attached to the switch box and attaches the sensor unit is provided. The attaching plate includes: an accommodating part that accommodates the sensor unit; and an outer peripheral edge part that is provided on a tip-end side outer periphery which is positioned on a side of the accommodating part where the sensor unit is inserted and that is arranged on a peripheral edge part on a tip-end side of the switch box. On the outer peripheral edge part, first screw holes corresponding to screw fixing parts of the switch box which are positioned on an inside of the switch box is formed.
(3) In the above configuration (2), each of the screw fixing parts of the switch box is bent from the peripheral edge part toward the inside of the switch box; and has a step height, which goes down in a direction from the peripheral edge part of the switch box toward the bottom part, between itself and the peripheral edge. The attaching plate includes folded-back parts each of which is provided at a position corresponding to each of the screw fixing parts in attachment to the switch box and is folded back from the outer peripheral edge part to a back side of the outer peripheral edge part which is to face a side of the screw fixing parts so as be fitted to the step height. The first screw hole is also formed in each of the folded-back parts.
(4) In the above configuration (3), the folded-back parts are folded back so as to separate from the outer peripheral edge part.
(5) In any one of the above configurations (2) to (4), the accommodating part includes: a bottom surface; a side wall part that is provided in a periphery of the bottom surface; and an elastic part that is provided on the bottom surface and elastically supports the sensor unit. The sensor unit has a second screw hole for passing an engagement screw that engages the sensor unit on a side of the bottom surface against an elastic force of the elastic part and performs positioning in a depth direction of the sensor unit. The bottom surface has an engagement screw fixing hole for fixing the engagement screw at a position corresponding to the second screw hole when the sensor unit is accommodated in the accommodating part.
(6) In any one of the above configurations (2) to (5), the accommodating part has a depth allowing the sensor unit to be arranged to be flush with at least the outer peripheral edge part.
(7) In any one of the above configurations (1) to (6), the switch box is a wide-type switch box that allows two or more switches to be arranged; and the sensor unit has two or more sensor parts each having one sensor substrate.
(8) In any one of the above configurations (1) to (7), the predetermined distance is 6.4 mm.

Effects of Invention

According to the present invention, a flat switch can be provided that prevents the flat switch from protruding and thereby causing a poor appearance even in a case where it is required to install a switch box so that an end part on an opening side of the switch box is not positioned on a predetermined distance or deeper side with respect to an appearance surface that is a front surface of a wall.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention (hereinafter, referred to as “embodiment”) will be described in detail with reference to attached drawings.

It should be noted that identical components are denoted by identical numbers through the entire description of the embodiment.

FIG. 1is an exploded perspective view for explaining an overall configuration of a flat switch1of an embodiment of the present invention.

As shown inFIG. 1, in the present embodiment, as a switch box100that is an attachment object of the flat switch1, the one commonly used in the U.S. is assumed.

Specifically, the switch box100includes: a bottom part101whose outer shape is nearly rectangular; and a vertical wall part102that is provided along an outer periphery of the bottom part101.

In the following description, a direction perpendicular to an X-axis direction (vertical direction) on the bottom part101is represented as a Y-axis direction and a direction perpendicular to an X-Y plane (depth direction) is represented as a Z-axis direction.

In addition, the switch box100includes screw fixing parts103each of which is folded from a peripheral edge part102A of a vertical wall part102that is an end part on an opening side of the switch box100toward an inside of the switch box100so as to be positioned at the inside of the switch box100and each of which has a step height going down to a deeper side (Z-axis direction negative side) between itself and the peripheral edge part102A (that is, a step height going down in a direction from the peripheral edge part102A of the switch box100toward the bottom part101).

In the present embodiment, a case where the switch box100is a wide-type switch box100that allows two switches to be arranged is shown.

The switch box100has a pair of screw fixing parts103provided on a pair of opposing sides of the peripheral edge part102A (a side along an X-axis direction on a Y-axis direction positive side and a side along the X-axis direction on a Y-axis direction negative side) so that each fixes one switch.

That is, on the side along the X-axis direction on the Y-axis direction positive side, a pair of the screw fixing parts103is provided with a distance apart between each other on the X-axis direction; while on the side along the X-axis direction on the Y-axis direction negative side, a pair of the screw fixing parts103is provided with a distance apart between each other on the X-axis direction.

A pair of the screw fixing parts103on one side and a pair of the screw fixing parts103on the other side are mutually opposed with a distance apart in the Y-axis direction.

As can be seen from the above description, the switch box100is configured to have a total of four pieces of the screw fixing part103.

In addition, on each of the screw fixing parts103, a first screw threaded hole103A on which a screw threaded groove, not illustrated, for threadedly engaging a screw N1is formed is formed.

It should be noted that it is not necessary to limit the switch box100to a wide-type one that allows two switches to be arranged and it may be a wide-type one that allows three or more switches to be arranged.

In addition, this switch box100is installed so that the peripheral edge part102A of the vertical wall part102is not positioned on a predetermined distance or deeper side (Z-axis direction negative side) (specifically, 6.4 mm) with respect to an appearance surface that is a front surface (outer surface) of a wall (for example, exterior wall).

On the other hand, the flat switch1includes: an attaching plate10that is attached to the switch box100; a sensor unit20that is attached so as to be accommodated on a front side (Z-axis direction positive side) of the attaching plate10; a power supply unit30that is attached to a back side (Z-axis direction negative side) of the attaching plate10; and a top panel40that is attached to the sensor unit20and closes an opening part of a wall on which the switch box is provided.

A top panel40includes: a transparent or translucent plate (part that can be seen inFIG. 1) that is positioned at a most front side (Z-side direction positive side); and a film (not illustrated) that is stuck on a back surface (surface on the Z-axis direction negative side) of the plate. On the film, printing of figures, characters, and the like that indicate a position for performing a switch operation and the like has been performed.

In addition, the film is configured to allow a predetermined area where at least figures, characters, and the like are printed to transmit light.

Specifically, the predetermined area where figures, characters, and the like are printed is in a state of a semitransparent mirror.

Therefore, when surroundings are dark such as at night, if, as described later, the sensor unit20emits light, the light causes figures, characters, and the like to be displayed as if they floated up.

On the other hand, when surroundings are bright such as during daytime, light is reflected by a semitransparent mirror and therefore, drawn figures, characters, and the like are brought into a state where they are visually recognized as-is by users, and a side of a back surface (surface on a Z-axis direction negative side) of the film is not seen transparently and thus the appearance is not deteriorated.

In addition, on a side of a back surface (surface on the Z-axis direction negative side) of the top panel40, engaging claws having an L shape (not illustrated) that engage with engagement parts JO provided on a side surface of the sensor unit20are provided and are detachably attached to the sensor unit20.

The power supply unit30includes, though detailed illustration is omitted, a control circuit and the like that control power which is supplied to the sensor unit20; and further includes a lead-out wiring31having a connector31A for electrical connection to the sensor unit20.

In addition, the lead-out wiring31is led out from the attaching plate10to a side where the sensor unit20is arranged and the connector31A is connected to the sensor unit20; accordingly, an electrical connection is performed between the power supply unit30and the sensor unit20.

Next, the attaching plate10will be described with reference mainly toFIG. 2toFIG. 7.

FIG. 2is a perspective view showing a state in which the attaching plate10is attached to the switch box100with the power supply unit30being attached.

In addition,FIG. 3is a perspective view when viewing a front side (Z-axis direction positive side), where the sensor unit20is attached, of the attaching plate10; anFIG. 4is a perspective view when viewing a back side (Z-axis direction negative side), where the power supply unit30is attached, of the attaching plate10; andFIG. 5is a side view when viewing the attaching plate10from the side of arrow A inFIG. 3.

In addition,FIG. 6is a perspective view showing the attaching plate10being attached to the switch box100; andFIG. 7is a view for explaining a folded-back part14A.

The attaching plate10is formed in a manner that one piece of plate material is folded; and as shown inFIG. 2toFIG. 6, includes: an accommodating part13having a bottom surface11and a side wall part12which is provided in a periphery of the bottom surface11; and an outer peripheral edge part14that is provided so as to be folded outward on a tip-end side outer periphery positioned on a side of the accommodating part13where the sensor unit is inserted, and that is arranged on the peripheral edge part102A (seeFIG. 1) on a tip-end side of the switch box100.

The bottom surface11includes, when viewed in a direction along a side of the switch box100where the screw fixing parts103are provided (X axis direction), a central side bottom surface11A and lateral side bottom surfaces11B provided on both sides of the central side bottom surface11A, so as to be fitted to the shape of the sensor unit20described later. The central side bottom surface11A is formed so as to be one-step deeper than the lateral side bottom surfaces11B when viewed from a front side (Z-axis direction positive side).

Further, though the reason will be described later, on the central side bottom surface11A, as shown inFIG. 2, both a fixing part18A that is riveted to the central side bottom surface11A and an elastic part18that has a pair of elastic sides18B each of which is provided on both sides of the fixing part18A are fixed.

It should be noted that although, in the present embodiment, the elastic part18is provided in pair separately in a direction (Y-axis direction) orthogonal to a direction (X-axis direction) along sides where the screw fixing parts103of the switch box100are provided, an arrangement aspect of the elastic part18is not limited to the above aspect.

The elastic part18may be an arrangement aspect other than the above aspect as long as it is an arrangement aspect capable of elastically supporting the sensor unit20.

In addition, the elastic part18is not necessarily limited to using an elastic member having a leaf spring structure as in the present embodiment, and it may be the one using an elastic member having another structure such as a spring structure, or the like.

On the other hand, as shown inFIG. 3andFIG. 4, on the side wall part12, recessed parts17corresponding to the screw fixing parts103are formed at positions facing the screw fixing parts103(seeFIG. 1) in attachment to the switch box100.

As described above, in the present embodiment, the switch box100that is commonly used in the U.S. is assumed. However, the standard in the U.S. only prescribes a positional relation of the first screw threaded holes103A (seeFIG. 1) of the switch box100and therefore, the length itself of the screw fixing part103where each of the first screw threaded holes103A is formed varies.

Then, the recessed parts17corresponding to the screw fixing parts103are provided on the side wall part12and thereby, even when there are variations in the length itself of the screw fixing parts103, it is prevented that the screw fixing parts103abut the side wall part12and the attaching plate10cannot be attached to the switch box100.

In addition, the attaching plate10includes, as described above, the outer peripheral edge part14that is arranged on the peripheral edge part102A (seeFIG. 1) of the switch box100and therefore, as shown inFIG. 2, when being attached to the switch box100, it can close an opening of the switch box100.

Further, on the central side bottom surface11A, as shown inFIG. 3andFIG. 4, a lead-out port15for leading out lead-out wiring31(seeFIG. 1) of the power supply unit30(seeFIG. 1), which is attached to the back side (Z-axis direction negative side) of the attaching plate10, to the front side (Z-axis positive side) where the sensor unit20is attached is formed. Also for this lead-out port15, a lid part16(seeFIG. 1) is attached so as to close the lead-out port15in a state where the lead-out wiring31is led out.

Further, as shown inFIG. 2andFIG. 6, in attaching the attaching plate10to the switch box100with the screws N1, closing plates19for closing the recessed parts17(seeFIG. 6) formed on the side wall part12are fastened together with the attaching plate10with the screws N1.

Specifically, as shown inFIG. 6, the closing plates19are arranged on the outer peripheral edge part14of the attaching plate10and each includes: an attaching plate part19A that has through holes19AA for passing the screws N1; and closing plate parts19B that are folded from the attaching plate part19A to a side of the side wall part12so as to perform arrangement at a position corresponding to the recessed parts17.

Thus, in the switch box100, the attaching plate10is attached so as to close the opening of the switch box100and both the lead-out port15and recessed parts17which are formed on the attaching plate10can also be closed; and therefore, generation of such a large gap as becoming a problem on the UL standards can be prevented and the UL standards prescribing that the opening of the switch box100should be closed without a gap can be satisfied.

Further, there are many in which the length of each of the screw fixing parts103of the switch box100is such a degree that does not cause contact with the side wall part12of the attaching plate10in a range of dispersion. Therefore, when the switch box100thus configured is selected and used, the recessed parts17do not need to be provided and also, the closing plates19can be omitted.

In addition, if the lead-out port15is large, the lid part16is necessary in order to satisfy the UL standards. However, with the lead-out port15having a size that is small enough not to cause a problem on the UL standards, the lid part16can be omitted.

However, with a configuration in which the recessed parts17are provided and the closing plates19close the recessed parts17, if the length of each of the screw fixing parts103(seeFIG. 1) of the switch box100is long and each of the closing plates19, itself, becomes an obstacle, the closing plates19are avoided from being used and thereby, the recessed parts17for accepting the screw fixing parts103are brought into an open state and accordingly the attaching plate10can be attached. Thus, time and effort to select the switch box100can be saved.

It should be noted that if, thus, the closing plates19are not used and the recessed parts17are open, the UL standards cannot be satisfied; however, since it is not obligatory to satisfy the UL standards, installation of the flat switch1does not become impossible.

Meanwhile, as described above, when the attaching plate10is manufactured by bending processing (for example, pressing molding), the attaching plate10can be manufactured at low cost; however, in order to make bending processing easily performed, it is difficult to increase the plate thickness of the attaching plate10.

Then, with reference toFIG. 1, as previously described, each of the screw fixing parts103of the switch box100is formed so as to have a step height that goes down on a deeper side (Z-axis direction negative side) between itself and the peripheral edge part102A.

Therefore, if the screws N1are fastened too tightly when the attaching plate10is fixed to the switch box100with the screws N1as shown inFIG. 2, parts P each of which is enclosed by a dotted line in the outer peripheral edge part14of the attaching plate10may be deformed so as to be lifted up on a side separating from the switch box100.

If so, the parts P will push up the back surface (surface on the Z-axis direction negative side) of the top panel40(seeFIG. 1) in a direction separating from the attaching plate10.

In addition, as described earlier, on the side of the back surface (Z-axis direction negative side) of the top panel40(seeFIG. 1), the engaging claws having an L shape (not illustrated) that engages with the engagement parts JO provided on the side surface of the sensor unit20(seeFIG. 1) are provided. However, as mentioned above, if the top panel40is pushed up in a direction separating from the attaching plate10, the top panel40separates also from the sensor unit20which is attached to the attaching plate10and this may cause a failure in engaging with the sensor unit20.

Therefore, in the present embodiment, as shown inFIG. 4, the attaching plate10includes the folded-back parts14A each of which is provided at a position corresponding to each of the screw fixing parts103in attachment to the switch box100and is folded back from the outer peripheral edge part14to a back side (Z-axis direction negative side), which is to face a side of the screw fixing parts103, of the outer peripheral edge part14so as to be fitted to the step height of each of the screw fixing parts103.

In addition, as shown inFIG. 3andFIG. 4, on the folded-back parts14A and the outer peripheral edge part14positioned on the folded-back parts14A, first screw holes H1which are fixed to the screw fixing parts103(seeFIG. 1) of the switch box100(seeFIG. 1) and allow the passing of screws N1(seeFIG. 1andFIG. 2) for attaching the attaching plate10to the switch box100are formed.

Thus, the folded-back parts14A which are fitted into the step heights of the screw fixing parts103are provided and therefore, stress which is added to the outer peripheral edge part14by an influence of the step heights in fastening the screws N1can be reduced; and even if the screws N1are firmly fastened, it can be prevented (restrained) that the parts P each of which is enclosed by a dotted line in the outer peripheral edge part14of the attaching plate10are deformed so as to be lifted up on a side separating from the switch box100, as described above.

This folded-back parts14A may be folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14as described with reference toFIG. 7; however, it is preferable to be folded back so as to separate from the outer peripheral edge part14to some extent; and the following provides a specific description with reference toFIG. 7andFIG. 8.

FIG. 7is a view for explaining the folded-back parts14A and is a view corresponding to a cross-section along line C-C shown inFIG. 3.

FIG. 7Ais a view showing a case in which each of the folded-back parts14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14; andFIG. 7Bis a view showing a case in which each of the folded-back parts14A is folded back so as to separate from the outer peripheral edge part14to some extent.

FIG. 8is an enlarged view of a periphery of one of the screw fixing parts103when the attaching plate10is arranged so that the outer peripheral edge part14contacts the peripheral edge part102A of the switch box100.

Further,FIG. 8Ais a case in which the folded-back part14A shown inFIG. 7Ais folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14; andFIG. 8Bis a case in which the folded-back part14A shown inFIG. 7Bis folded back so as to separate from the outer peripheral edge part14to some extent.

As described above, in order to easily perform bending processing, it is difficult to increase the plate thickness of the attaching plate10.

Therefore, if, as shown inFIG. 7A, each of the folded-back parts14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14, a thickness in a cross-section of part which is constituted by the outer peripheral edge part14and the folded-back part14A is thickness 2t that is twice the thickness t but the plate thickness t is thin and thickness 2t is also not so thick.

On the other hand, if, as shown inFIG. 7B, each of the folded-back parts14A is folded back so as to separate from the outer peripheral edge part14to some extent, thickness t′ in a cross-section of part which is constituted by the outer peripheral edge part14and the folded-back part14A can be made thicker than thickness 2t.

In addition, if, as shown inFIG. 7B, the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent, it is structured that when the folded-back part14A is brought close to the outer peripheral edge part14, an elastic force acts in a direction of separation.

However, since height H (height in a Z-axis direction) of the step height that goes down to a deep side (Z-axis direction negative side) between the screw fixing part103and the peripheral edge part102A, which is shown inFIG. 8, is not defined in specifications of the switch box100and therefore, though there are variations, in most cases, it is a step height higher than thickness 2t (seeFIG. 7AandFIG. 8A) and, by extension, thickness t′ (seeFIG. 7BandFIG. 8B).

Further, in a case in which the height H of the step height is lower than the thickness 2t, when the attaching plate10is arranged on the switch box100, a gap of at least a width which is obtained by subtracting the height H of the step height from the thickness 2t is generated between the attaching plate10and the peripheral edge part102A of the switch box100; however, in a case in which the height H of the step height is higher than at least thickness 2t, such gap is never generated.

In addition, the height H of the step height is higher than thickness 2T (seeFIG. 8A) and, by extension, thickness t′ (seeFIG. 8B) and therefore, when the attaching plate10is arranged so that the outer peripheral edge part14contacts the peripheral edge part102A of the switch box100, a gap is generated between the screw fixing part103and the folded-back part14A.

Specifically, as shown inFIG. 8A, in a case in which the folded-back part14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14(in the case ofFIG. 7A), a gap of distance D is generated between the screw fixing part103and the folded-back part14A.

In addition, as shown inFIG. 8B, in a case in which the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s) (in the case ofFIG. 7B), a gap of distance D′ is generated between the screw fixing part103and the folded-back part14A.

It should be noted that distance D′ is a distance that is smaller than distance D by distance s.

Here, if force FO1that is necessary to fasten each of the screws N1in fixing the attaching plate10is a force that is larger than the one for changing the plate thickness t which is the thickness of the outer peripheral edge part14mounted on the peripheral edge part102A of the switch box100, it may tighten the screw N1at least until the folded-back part14A contacts the screw fixing part103; and in the case shown inFIG. 8A, a situation where the outer peripheral edge part14is deformed by distance D may occur.

In addition, if the folded-back part14A is not provided, a situation where the outer peripheral edge part14is deformed by the height H of the step height may occur. Therefore, as mentioned earlier, even in a case shown inFIG. 8A, the deformation of the outer peripheral edge part14can be reduced more than in a case in which the folded-back part14A is not provided.

On the other hand, if force FO1that is necessary to fasten each of the screws N1in fixing the attaching plate10is a force that is larger than the one for changing the plate thickness t which is the thickness of the outer peripheral edge part14mounted on the peripheral edge part102A of the switch box100, the force FO1, as shown inFIG. 8B, does not exceed a force which is obtained by adding an elastic force FO2, which is generated by the folding back of the folded-back part14A so as to separate from the outer peripheral edge part14to some extent, to a rigidity force FO3of the plate thickness t (FO1<FO2+FO3), the fastening of the screw N1stops at a point where the folded-back part14A contacts the screw fixing part103.

Therefore, the deformation of the outer peripheral edge part14occurs only by within distance D′ that is smaller than distance D (seeFIG. 8A) and the deformation of the outer peripheral edge part14can be significantly reduced.

Thus, a case in which the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s) (the case ofFIG. 7B) is preferable because it allows the deformation of the outer peripheral edge part14to be more easily reduced than a case in which the folded-back part14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14(the case ofFIG. 7A).

In addition, even if the force FO1that is necessary to fasten each of the screws N1in fixing the attaching plate10exceeds a force that is obtained by adding the elastic force FO2to the rigidity force FO3of the plate thickness t (FO1>FO2+FO3), the screw N1can be fastened only up to a state in which the folded-back part14A contacts the outer peripheral edge part14(a state in which the distance s is 0). Therefore, the deformation of the outer peripheral edge part14does not become larger than in the case described inFIG. 8A.

In addition, as shown inFIG. 7BandFIG. 8B, in a case in which each of the folded-back parts14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s), after each of the screw N1is fastened, an elastic force between the folded-back part14A and the outer peripheral edge part14act so as to prevent the screw N1from being loosened and therefore, effects similar to prevention of loosening by a spring washer are exerted.

Further, it is considered that if an inner diameter of each of the first screw holes H1(FIG. 8) for passing each of the screws N1(seeFIG. 1andFIG. 2), the first screw holes H1being formed on the folded-back parts14A, is such a degree that at least part of the screw N1comes into contact at the time of a fastening work for fixing the attaching plate10, also at a stage prior to the folded-back parts14A contacting the screw fixing parts103, a stress added to the outer peripheral edge part14can be more reduced when the folded-back parts14A are folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s) as shown inFIG. 7BandFIG. 8Bthan when the folded-back parts14A are folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14as shown inFIG. 7AandFIG. 8A.

Specifically, when part of each of the screw N1is in contact with an inner peripheral surface of the first screw hole H1(FIG. 8) of each of the folded-back parts14A, the folded-back part14A is brought into a state of being hard to move due to a factor such as a swing resistance with the screw N1.

In addition, in this state, if a force for being pressed to a side of the folded-back part14A acts on the outer peripheral edge part14, the outer peripheral edge part14is trying to bend to the side of the folded-back part14A. However, as described earlier, when a gap (distance s) between the folded-back part14A and the outer peripheral edge part14becomes small, a force acts, due to an elastic force FO2, on a side where the folded-back part14A and the outer peripheral edge part14are separated.

Therefore, due to this force that acts on a side where the folded-back part14A and the outer peripheral edge part14are separated, a force for pressing the outer peripheral edge part14on the side of the folded-back part14A is weakened and a stress added to the outer peripheral edge part14is reduced.

Further, as shown inFIG. 7AandFIG. 8A, if the folded-back part14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14, it is not a structure that exerts an elastic force and therefore, it is considered that an effect of reducing a stress, which is added to the outer peripheral edge part14, due to the elastic force FO2as described above is not exhibited.

Thus, it is considered that when the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s) as shown inFIG. 7BandFIG. 8B, an effect of reducing a stress which is added to the outer peripheral edge part14can be increased more than when the folded-back part14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14, as shown inFIG. 7AandFIG. 8A.

On the other hand, if an inner diameter of each of the first screw holes H1(FIG. 8) for passing each of the screws N1(seeFIG. 1andFIG. 2), the first screw holes H1being formed on the outer peripheral edge part14, is such a degree that at least part of the screw N1comes into contact at the time of a fastening work for fixing the attaching plate10, it is considered that the screw N1contacts the inner peripheral surface of the first screw hole H1(FIG. 8) of the outer peripheral edge part14and the outer peripheral edge part14is brought into a state of being hard to move due to a factor such as a swing resistance with the screw N1; and when a force for pressing to the side of the folded-back part14A is added to the outer peripheral edge part14, the occurrence of bending of the outer peripheral edge part14is prevented as much as the outer peripheral edge part14becomes hard to move.

This holds true for both the case in which the folded-back part14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14as shown inFIG. 7AandFIG. 8Aand the case in which the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s) as shown inFIG. 7B andFIG. 8B.

From this, the inner diameter of each of the first screw holes H1(FIG. 8) for passing each of the screws N1(seeFIG. 1andFIG. 2), the first screw holes H1being formed on the outer peripheral edge part14, is also desirable to be such a degree that at least part of the screw N1easily comes into contact at the time of a fastening work for fixing the attaching plate10.

Thus, the inner diameter of the first screw hole H1(FIG. 8) of the outer peripheral edge part14and folded-back part14A is preferable to be such a degree that at least part of the screw N1can come into contact at the time of a fastening work for fixing the attaching plate10.

In addition, as shown inFIG. 7AandFIG. 8A, even in a case in which each of the folded-back parts14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14, if the screw N1contacts the inner peripheral surface of the first screw hole H1(FIG. 8) of the folded-back part14A, a swing resistance and the like occur and, as with the earlier description, the folded-back part14A is brought into a state of being hard to move and the outer peripheral edge part14, which is in a state of being accepted in the folded-back part14A, also becomes hard to move. Therefore, by making the inner diameter of the first screw hole H1(FIG. 8) small, the outer peripheral edge part14can be made hard to bend (hard to deform) at a stage prior to the folded-back part14A contacting the screw fixing part103.

However, as shown inFIG. 7BandFIG. 8B, when the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s), an effect of reducing a stress, which is added to the outer peripheral edge part14, due to an elastic force FO2, can be further expected as described earlier. Therefore, it is still preferable that the folded-back part14A is folded back so as to separate from the outer peripheral edge part14to some extent (separation by distance s) as shown inFIG. 7BandFIG. 8B, as compared to a case in which the folded-back part14A is folded back so as to contact the back side (Z-axis direction negative side) of the outer peripheral edge part14as shown inFIG. 7AandFIG. 8A.

In addition, if the folded-back part14A is not formed, an inner peripheral surface of the first screw hole H1(FIG. 8) which the screw N1can contact is only the inner peripheral surface of the first screw hole H1(FIG. 8) of the outer peripheral edge part14; however, if the folded-back part14A is formed, the screw N1can contact also the inner peripheral surface of the first screw hole H1(FIG. 8) of the folded-back part14A. The forming of the folded-back part14A doubles the probability that the screw N1will come in contact, and increases the probability that the outer peripheral edge part14can be made hard to bend (hard to deform) due to effects such as a swing resistance as described above and therefore, also from this respect, it is preferable that the folded-back part14A is provided irrespective of whether or not the folded-back part14A separates from the outer peripheral edge part14to some extent (separation by distance s).

On the other hand, in the folded-back part14A, a part close to the side wall part12, which does not prevent fitting into the step height, (that is, a part that is to be positioned at an inner side than the peripheral edge part102A of the switch box100shown inFIG. 1) is configured as a wide part14B that is wider than the width of the step height. Specifically, as shown inFIG. 4, each of the wide parts14B is formed so as to have a width wider than a width along the side wall part12of the recessed part17.

A part of the outer peripheral edge part14of the attaching plate10, which corresponds to a part where this recessed part17is provided, is a part of a flat plate shape and is a part that does not have a rib structure by the side wall part12and therefore, has a strength lower than a part where the side wall part12is provided.

However, the wide part14B is provided so as to increase the strength of the part having a lower strength and therefore, deformation that is caused when the screw N1is fastened as described above can be further reduced.

Next, the sensor unit20will be described with reference mainly toFIG. 9toFIG. 11.

FIG. 9is a plan view when viewing a front side (Z-axis direction positive side) of the sensor unit20;FIG. 10is a cross-sectional view taken by cutting the sensor unit20along line B-B shown inFIG. 9; andFIG. 11is a partial cross-section view for explaining a sensor substrate50.

The sensor unit20includes, as shown inFIG. 9andFIG. 10: a casing21; two sensor parts22that are provided within the casing21; and a control part23that is provided within the casing21.

As shown inFIG. 10, the casing21includes: a frame part21athat is a peripheral wall; a partitioning part21bthat is formed inside the frame part21a; and a connection part21cthat is formed so as to penetrate the partitioning part21b. The partitioning part21bis formed so as to be positioned at an intermediate position (an almost center position in this example) of the height of a front-back direction (Z-axis direction) of the frame part21a.

In addition, the sensor parts22are arranged within a recessed part24on a front side (Z-axis direction positive side) of the casing21; and the control part23is arranged in a recessed part25on a back side (Z-axis direction negative side) of the casing21.

The sensor parts22each includes: the sensor substrate50that is electrically connected to a control substrate60of the control part23by the connection part21c; an electrostatic sensor IC51that is provided on a back surface side (Z-axis direction negative side) of the sensor substrate50; and a light emitting part52.

The light emitting part52includes: a case52A whose front surface side (Z-axis direction positive side) is open; a light source52B (for example, LED) that is arranged at one end side of the case52A; a light emitting layer52C; and a flexible wiring substrate52D that electrically connects the light source52B to a feeding pattern for supplying power to the light source52B that is formed at a part of one end side of the sensor substrate50.

The light emitting layer52C includes: a light guide plate52CA; a reflection member52CB (for example, reflection sheet or reflection plate) that is arranged on a back surface side (Z-axis direction negative side) of the light guide plate52CA; and light diffusion members (diffusion sheet52CC and prism sheet52CD) that are arranged on a front surface side (Z-axis direction positive side) of the light guide plate52CA.

In addition, the light source52B is arranged so that a light emitting surface faces a side surface of the light guide plate52CA; and when the light source52B is made to emit light, light enters from the side surface of the light guide plate52CA into the light guide plate52CA.

While this incident light is guided within the light guide plate52CA, part of the light is emitted from a front surface (surface on the Z-axis direction positive side) of the light emitting layer52C so that a front surface (surface on the Z-axis direction positive side) of the light emitting layer52C is uniformly lit through the light diffusion members (diffusion sheet52CC and prism sheet52CD).

In addition, by the light which is emitted from the front surface (surface on the Z-axis direction positive side) of this light emitting layer52C, the figures, characters, and the like which are provided on the top panel40as described earlier, can be floated up and therefore, even at night or the like, the figures and characters can be visually recognized.

Further, as shown inFIG. 9, the sensor unit20includes a human sensor26described later and for example, if the human sensor26detects that a person exists near the flat switch1during a time period such as night, the light source52B is made to emit light.

On the other hand, as shown inFIG. 11A, on a part which is made to function as an electrostatic capacitance sensor of a front surface50A (Z-axis direction positive side) of the sensor substrate50, conductive patterns that become a drive line50AA and a sensor line50AB are formed. On the front surface50A (surface on the Z-axis direction positive side) and back surface50B (surface on the Z-axis direction negative side) of the sensor substrate50, conductive patterns which become grounds50AC electrically connected with each other are formed. The state of an electric field is indicated as electric force lines by arrows. Between the drive line50AA, the sensor line50AB, and the grounds50AC, an electric field is generated.

In this state, when a human finger F approaches as shown inFIG. 11B, electric force lines are drawn to a side of the finger F and the number of electric force lines to the sensor line50AB is reduced.

The electrostatic sensor IC51(seeFIG. 10) detects this reduction in the electric force lines, that is, a change in electrostatic capacitance and thereby whether or not a switch operation has been performed is detected.

A configuration of the electrostatic sensor is not limited to the above configuration of detecting a change in electric force lines; however, in the case of the configuration of detecting a change in the electric force lines as in the present embodiment, even when the finger F is apart from the front surface50A (surface on the Z-axis direction positive side) of the sensor substrate50, detection is possible only by the presence of the finger F in its vicinity.

Therefore, even when the light emitting layer52C, the top panel40, and the like are arranged on a side of the front surface50A (side of the surface on the Z-axis direction positive side) of the sensor substrate50, it can be excellently detected that the finger F has approached.

The control part23is a part for performing overall control of the flat switch1and includes, as shown inFIG. 10: a control substrate60; a control IC61that is installed on a surface of the control substrate60facing a side of the partitioning part21bof the casing21; and a wireless antenna62that is installed on a surface of the control substrate60facing the side of the partitioning part21bof the casing21.

In addition, as shown inFIG. 9andFIG. 10, in the casing21, a through hole HO1is provided at a position corresponding to an antenna part62A of the wireless antenna62, so that communication between an apparatus that is an object to be operated by the flat switch1and the wireless antenna62is not interfered.

Further, on the surface of the control substrate60facing the side of the partitioning part21bof the casing21, the human sensor26(seeFIG. 9) is also arranged; and on the casing21, a through hole HO2for arranging the human sensor26is provided.

Here,FIG. 10is one that shows a cross-section of a part in which the control part23of the sensor unit20is provided; and is a part in which the thickness of a part in which this control part23is provided is the thickest in the sensor unit20. In the present embodiment, the thickness is approximately 9 mm.

On the other hand, as described earlier, in installing the switch box100in compliance with the standard for electrical wiring and electrical installation of equipment called NEC (National Electrical Code), the switch box100is to be installed so that the peripheral edge part102A of the vertical wall part102is not positioned on a 6.4 mm or deeper side (Z-axis direction negative side) with respect to the appearance surface that is a front surface (outer surface) of a wall (for example, an exterior wall).

For this reason, if a flat plate is installed so as to close the opening of the switch box100and the sensor unit20is attached to the plate, the sensor unit20will protrude from the appearance surface that is a front surface (outer surface) of a wall (for example, an exterior wall).

Therefore, by making the outer shape of the sensor unit20into an outer shape that is smaller than an inner shape defined by the peripheral edge part102A of the switch box100, it has been made possible that the sensor unit20is arranged so as to be embedded into the switch box100.

Specifically, as shown inFIG. 9, width W1of the sensor unit20, which is arranged along a side on which the screw fixing parts103(seeFIG. 1) of the peripheral edge part102A (seeFIG. 1) of the switch box100(seeFIG. 1) are provided, is set to a width that is smaller than a separation distance between opposed peripheral edge parts102A (seeFIG. 1) in which the screw fixing parts103(seeFIG. 1) are not provided; and width W2of the sensor unit20in a direction orthogonal thereto (Y-axis direction) is set to a width smaller than a separation distance between the opposed screw fixing parts103(seeFIG. 1).

In addition, as described above, the attaching plate10including the accommodating part13(seeFIG. 2), which accommodates the sensor unit20that has an outer shape allowing embedding into the switch box100, is attached and thus, it has been made possible that the sensor unit20is installed so as to be embedded into the switch box100.

Next, procedures for installing the flat switch1will be described with reference toFIG. 1and a more detailed configuration will be described.

First, the switch box100is installed within an opening part which is provided on a wall (for example, an exterior wall) to embed the switch box100.

Specifically, the switch box100is installed so that the peripheral edge part102A of the vertical wall part102of the switch box100is positioned on a deeper side (Z-axis direction negative side) by a degree of the plate thickness of a plate material that is a forming material of the attaching plate10than an appearance surface that is a front surface (outer surface) of the wall (for example, exterior wall).

In addition, the plate material that is a forming material of the attaching plate10has a plate thickness of only several mm or less and therefore, even when the switch box100is installed as described above, the provision that installation should be performed so that the peripheral edge part102A of the vertical wall part102is not positioned on 6.4 mm or deeper side (Z-axis direction negative side) with respect to the appearance surface, which is stipulated in the standard for electrical wiring and electrical installation of equipment called NEC (National Electrical Code), can be sufficiently satisfied.

Next, the power supply unit30is attached to a back surface (surface on the Z-axis direction negative side) of the attaching plate10, the lead-out wiring31including the connector31A of the power supply unit30is led out from a lead-out port15(seeFIG. 3andFIG. 4) of the attaching plate10to a front surface side (side of a surface on the Z-axis direction positive side) of the attaching plate10, and the lid part16is fixed to the central side bottom surface11A (seeFIG. 3) by a screw so as to close the lead-out port15.

In addition, as described with reference toFIG. 6, the attaching plate10and the closing plates19are fastened together to the screw fixing parts103(seeFIG. 1) of the switch box100by screws N1.

When the attaching plate10is thus fixed, the peripheral edge part102A of the vertical wall part102of the switch box100is positioned on a deeper side (Z-axis direction negative side) by a degree of the plate thickness of the attaching plate10and therefore, the outer peripheral edge part14of the attaching plate10is in a state of being approximately flush with the appearance surface.

Further, when the attaching plate10is attached to the switch box100and a state indicated byFIG. 2is set, subsequently, the connector31A is connected to the sensor unit20and the sensor unit20is arranged within the accommodating part13of the attaching plate10, and a work for fixing the sensor unit20to the attaching plate10is performed.

Specifically, as shown inFIG. 2, the central side bottom surface11A of the attaching plate10is formed so that its depth is one-step deeper as viewed from a front side (Z-axis direction positive side) than the lateral side bottom surface11B, in correspondence with a part of the control part23(seeFIG. 10) that is a part in which the thickness of the sensor unit20is thick; and on its central side bottom surface11A, the elastic part18for elastically supporting the sensor unit20is provided.

In addition, when the sensor unit20is arranged within the accommodating part13so as to make the elastic part18perform elastic support, the positions of the engagement screw fixing holes11BH which are provided on ends of the lateral side bottom surface11B shown inFIG. 3and on each of whose inner peripheral surface a screw threaded groove for threadedly engaging each of the engagement screws N2(seeFIG. 1) is formed and the positions of the second screw holes27which are provided at four corners of the casing21shown inFIG. 9and are for passing the engagement screws N2correspond to each other.

Therefore, when each of the engagement screws N2is threadedly engaged with each of the engagement screw fixing holes11BH through each of the second screw holes27of the sensor unit20, the sensor unit20is to be engaged on a side of the bottom surface11by the engagement screws N2against an elastic force (energizing force) of the elastic part18.

In addition, by adjusting the amount of threaded engagement of the engagement screws N2to the engagement screw fixing holes11BH, positioning in a depth direction of the sensor unit20can be performed and therefore, positioning is performed so that the outer peripheral edge part14of the attaching plate10and the sensor unit20are made flush with each other by adjusting the amount of threaded engagement, thereby bringing the sensor unit20into a state of being substantially flush with the appearance surface, as with the outer peripheral edge part14.

Further, even if the switch box100is installed on still about several mm deeper side (Z-axis direction negative side), an installation state which is prescribed in the standard for electrical wiring and electrical installation of equipment called NEC (National Electrical Code) can be obtained; however, it is only possible if errors and the like are not considered and substantially, there is no room for installation on a deeper side (Z-axis direction negative side) than this.

Therefore, it is considered that the attaching plate10is to be fixed to the switch box100so that the outer peripheral edge part14of the attaching plate10is brought into a state of being substantially flush with the appearance surface. In order to perform installation for the sensor unit20not to protrude from the appearance surface, the accommodating part13of the attaching plate10is preferable to have a depth that allows the sensor unit20to be arranged to be flush with at least the outer peripheral edge part14.

Lastly, in order to improve the appearance by preventing the opening part provided on a wall (for example, exterior wall) for embedding the switch box100, the sensor unit20, and the like from being visually recognized, the engaging claws having an L shape of the top panel40(not illustrated) are engaged with the engagement parts JO provided on the side surface of the sensor unit20and the top panel40is attached to the sensor unit20. Then, the installation work of the flat switch1ends.

As described above, in the present embodiment, first, the outer shape of the sensor unit20is made into an outer shape that is smaller than an inner shape defined by the peripheral edge part102A of the switch box100and thereby, the sensor unit20is allowed to be arranged so as to be embedded in the switch box100; and therefore, in the switch box100which is arranged so that the peripheral edge part102A is not positioned on a predetermined distance (specifically 6.4 mm) or deeper side (Z-axis negative side) with respect to an appearance surface that is a front surface of the wall, even the sensor unit20that has a thickness of approximately 9 mm at the thickest portion in a direction (Z-axis direction) from the peripheral edge part102A of the switch box100toward the bottom part101in a state of being installed in the switch box100can be installed so as not to protrude from the appearance surface.

Then, by using the attaching plate10that allows positional adjustment in a direction of the depth of the sensor unit20, the sensor unit20can be easily installed so as to become substantially flush with the appearance surface.

The present invention has been described based on the embodiment so far; however, the present invention is not limited to the embodiment.

For example, in the above embodiment, the sensor part22of the sensor unit20includes the light emitting part52so that the sensor unit20emits light; however, it is not necessary that the sensor unit20emits light in performing a function as the flat switch1; and there is not any problem that the light emitting part52is omitted.

Thus, the present invention is not limited to the specific embodiment and can be modified without departing from the spirit thereof, which is obvious to a person skilled in the art from the description of claims.

LIST OF REFERENCE SIGNS