[0001] The invention relates to a sanitary device seat, comprising a ring- or U-shaped seat
body and at least one capacitive element adapted to provide a sensing signal processible
to a seat occupancy information.
[0002] Many comfort features of modern sanitary devices, frequently called electric toilets
or electric bidets, require an occupancy information describing whether the sanitary
device seat is occupied or not. It is known to attach a microswitch to the sanitary
device, whereby the microswitch is switched by a vertical displacement occurring when
a user takes seat. Furthermore, it is known to arrange a capacitor module with a capacitive
element and an integrated signal processing into the seat body. The capacitor module
detects a change of the permittivity resulting from an approach of a human body to
the sanitary device seat.
[0003] This kind of capacitive proximity sensing suffers from the large dimensions of known
capacitor modules, requiring to divide the seat body into two pieces laterally, to
arrange the capacitor module between them and to reassemble both pieces. Disadvantageously,
the production of those sanitary device seats is very complex and the further reduction
of the thickness of the sanitary device seat is rendered difficult.
[0004] Therefore, it is an object to the invention to provide a more easily manufacturable
sanitary device seat of reduced thickness.
[0005] This is inventively achieved by a sanitary device seat as initially described, whereby
the capacitive element is arranged at the seat body and covered by an overlay coating
the seat body.
[0006] The invention bases on the consideration to place the capacitive element between
the seat body specifying the basic form of the sanitary device seat, and the overlay,
building an outer skin of at least parts of the sanitary device seat. Thus, the seat
body may be only as thick as necessary to match mechanical stability requirements,
whereby a particularly flat capacitive element may be arranged at the seat body and
coated by the overlay, as well. Advantageously, this allows the sanitary device seat
to be manufactured with a very small cross-sectional height. Additionally, the manufacturing
process of the inventive sanitary device seat may be simplified significantly since
dividing and reassembling the seat body, e.g. by welding, is avoided.
[0007] The capacitive element used for the inventive sanitary device seat should be chosen
very thin, e.g. having a cross-sectional height which is at most a tenth, preferably
at most a hundredth, of the cross-sectional height of the seat body. Particularly,
the capacitive element may have a cross-sectional height between 10 µm and 1 mm. This
allows the capacitive element to remain invisible from the exterior of the sanitary
device seat when the seat body is coated with the respectively thin overlay. The capacitive
element may be arranged directly on the surface of the seat body. Furthermore, the
sanitary device seat may comprise a connector, arranged to connect the capacitive
element from the exterior of the sanitary device seat. The connector may be adapted
to provide an external electric signal to the capacitive element and/or to provide
the seat occupancy information or a signal processible to the seat occupancy information
to the exterior of the sanitary device seat. The ring-shaped sanitary device seat
may be considered as O-shaped, as well, meaning that the seat fully surrounds an opening
for a person to sit on, whereas the U-shaped seat does not surround the opening completely.
A typical inventive sanitary device may also comprise a lid, attached to the sanitary
device seat and adapted to cover the opening of the sanitary device seat in a closed
position and/or to allow a user to sit on the sanitary device seat in an opened position.
[0008] Preferably, the capacitive element is or comprises a looped coil. Such a looped coil
may be made of a thin wire being wounded one or several times on a free end, forming
a capacitor structure whose capacitance may change due to an approach of an object
having a relative permittivity significantly higher than 1, e.g. the human body. The
other free end of the wire may be connected to the connector. Alternatively or additionally
the capacitive element comprises or is a capacitive foil. Such a capacitive foil is
comparable to those used for touch screens etc. The capacitive element may be or comprise
a printed circuit, as well. The printed circuit may comprise a wiring made of an electrically
conductive material forming a capacitor structure. Furthermore the capacitive element
may be realized by laser direct structuring. This way, the capacitor structure may
be drawn on the seat body by a laser and electroplated afterwards. Of course, a plurality
of capacitive elements may be arranged at the seat body, particularly distributed
over its surface.
[0009] Furthermore, the capacitive element may be glued on the seat body. This allows a
very feasible arrangement and fixation of the capacitive element at the seat body.
Alternatively or additionally the capacitive element is fixed by in-mold-decoration
at the seat body. According to a very feasible embodiment of the inventive sanitary
device seat, the capacitive element is fixed by the coating.
[0010] Advantageously, the seat body is made of one piece. As already mentioned, several
steps required for the manufacture of conventional sanitary device seats may be saved,
such as dividing and reassembling. Particularly, the seat body is free of joining
seams.
[0011] Moreover, the sanitary device seat may have a thickness of the most 10 mm, preferably
at most 7 mm, more preferably at most 5 mm, with a minimal thickness of 3 mm. Thickness
may be defined as the sanitary device seat's cross-sectional height.
[0012] Particularly, the overlay is painted and/or glued and/or plated and/or laminated
on the seat body. Those surface processing methods have been found out as very useful
for a further simplification of the manufacturing process of the inventive sanitary
device seat.
[0013] Additionally, the seat body may be made from a plastic material, particularly comprising
polypropylene and/or acrylnitril-butadien-styrol and/or urea-formaldehyde resin, and/or
a composite material and/or wood. Those materials are very suitable for the above-mentioned
methods of fixing the capacitive element and/or realizing the overlay. However, the
material of which to seat body is made is not limited to the aforementioned materials.
[0014] Aside, the invention relates to a sanitary device, comprising an inventive sanitary
device seat.
[0015] A typical inventive sanitary device may also comprise a bowl, especially made of
ceramics, to which the sanitary device seat is attached. Alternatively to the lid
being attached to the sanitary device seat as mentioned above, the lid may be attached
to the bowl. The sanitary device may be adapted as a toilet and/or for washing parts
of the human body (bidet). The inventive sanitary device may furthermore comprise
a connector adapted to fit to the connector of the sanitary device seat.
[0016] The inventive sanitary device may comprise a signal processing unit being adapted
to determine the seat occupancy information depending on the sensing signal. The signal
processing unit may be connected to the capacitive element, particularly via the connector
of the sanitary device seat and/or the other connector. In general, the signal processing
unit may be adapted to supply a voltage and/or a current to the capacitive element.
[0017] Preferably, the signal processing unit is adapted to apply an alternating, particularly
rectangular or trapezoidal, current to the capacitive element. Particularly, if a
passive capacitive element is used, e.g. the looped coil, the capacitive foil or a
capacitive element realized by laser direct structuring, the temporary constant current
will charge the capacitor realized by the capacitive element resulting in a nearly
linear change of voltage dropping over the capacitive element. The magnitude of this
change depends on the capacitance which depends again on the permittivity being changed
by the object, e.g. the human body. Thus, a very reliable sensing signal is provided
by the capacitive element.
[0018] Advantageously, the signal processing unit is adapted to measure a voltage dropping
over the capacitive element as the sensing signal. The signal processing unit may
additionally be adapted to evaluate this voltage and to determine the occupancy information
basing on the evaluation result. The voltage is preferably the aforementioned voltage
resulting from the applied current.
[0019] The signal processing unit or a respective signal processing unit may be arranged
between the seat body and the overlay of the inventive sanitary device seat. In this
case the capacitive element is or comprises the printed circuit and/or is integrated
with the signal processing unit, preferably. Alternatively, the signal processing
unit may be disposed outside the sanitary device seat. This allows the sanitary device
seat to be composed merely of the coated seat body, the capacitive element and its
connector, rendering a very thin realization of the sanitary device seat possible.
[0020] Referring to the inventive sanitary device, it may comprise a control unit being
adapted to control at least one functional component of the sanitary device depending
on the occupancy information. Preferably, the functional component is or comprises
a spraying unit adapted to spray a liquid towards a human body sitting on the sanitary
device seat and/or a blowing unit adapted to blow air towards a human body sitting
on the seat and/or a heating unit adapted to heat the sanitary device seat and/or
a flushing unit and/or a movement device adapted to close a lid of the sanitary device
and/or a deodorization unit. However, the at least one functional component is not
limited to the aforementioned devices.
[0021] Advantageously, a service device is arranged separately from the sanitary device
seat and incorporating the control unit and/or the signal processing unit, which is
disposed outside the sanitary device seat, in a housing. Providing the service device
allows the sanitary device seat to have a reduced thickness of its entire dimensions.
The connector fitting to the connector of the sanitary device seat may be attached
to the service device.
[0022] Besides, a method for manufacturing a sanitary device seat is disclosed, comprising
the steps: providing a seat body; arranging at least one capacitive element adapted
to provide a sensing signal processible to a seat occupancy information at the seat
body; and covering the seat body by an overlay coating it. A looped coil and/or a
capacitive foil and/or a printed circuit may be used as capacitive element and/or
the capacitive element may be realized by laser direct structuring. Arranging the
capacitive element at the seat body may comprise gluing the capacitive element and/or
fixing the capacitive element by in-mold-decoration at the seat body. Covering the
seat body may comprise fixing the capacitive element by the coating. Furthermore,
covering the seat body may comprise painting and/or gluing and/or plating and/or laminating
the seat body. A seat body made of one piece and/or having a thickness of at most
10 mm, preferably 7 mm, more preferably 5 mm, with a minimum thickness of 3 mm, may
be used.
[0023] All statements referring to the inventive sanitary device seat may apply analogously
to the inventive sanitary device and the aforementioned method, so that advantages
achieved by the inventive sanitary device seat may be achieved by the inventive sanitary
device and the aforementioned method, as well.
[0024] In the following, the invention is described in detail, whereby references are made
to the principle drawings, which show:
- Fig. 1
- a perspective view of an inventive sanitary device, comprising a first embodiment
of an inventive sanitary device seat;
- Fig. 2
- a top view on a first embodiment of the sanitary device seat shown in fig. 1;
- Fig. 3
- a cross-section of the sanitary device seat shown in fig. 2 along a line III-III;
- Fig. 4
- a block diagram of the sanitary device shown in fig. 1;
- Fig. 5
- time curves of the measured voltage provided by a capacitive element while a test
process;
- Fig. 6
- a cross-section of a further embodiment of an inventive sanitary device seat; and
- Fig. 7 and 8
- each a top view on a further embodiment of an inventive sanitary device seat;
[0025] Fig. 1 shows a perspective view on a sanitary device 1, comprising a ring-shaped
sanitary device seat 2 (in the following simply referred to as seat 2) which is arranged
on a bowl 3. According to further embodiments the seat may be U-shaped. A lid 4 is
attached pivotly to the seat 2 to cover it in a closed position and to allow a person
to sit on the seat 2 in an opened position. The bowl 3 is connected to a sewer system
and has a cistern 5 with an operating element 6 to initiate flushing. Within the seat
2 a capacitive element 7 is arranged adapted to provide a sensing signal processible
by a signal processing unit 8 to a seat occupancy information. The signal processing
unit 8 and a control unit 9 are incorporated in a housing of a service device 10 being
arranged separately from the seat 2. A connector 11 of the service device 10 is connected
to a further connector 12 (cf. Fig. 2) arranged at the seat 2, whereby the capacitive
element 7 is connected to the signal processing unit 8 via both connectors 11, 12.
[0026] Besides, the sanitary device 1 comprises further functional components 13, which
are not shown in detail for reasons of clarity. The functional components 13 are controllable
by the control unit 9 and comprise a spraying unit adapted to spray a liquid towards
the human body sitting on the seat 2, a blowing unit adapted to blow warmed air towards
the human body, a heating unit adapted to heat the seat 2, a flushing unit adapted
to flush the bowl 3 by allowing water from the cistern 5 to flow into the bowl 3,
a movement device adapted to close the lid 4 and a deodorization unit. Note, that
this enumeration is not exhaustive.
[0027] Fig. 2 shows a top view on the seat 2, comprising the capacitive element 7 and the
connector 12 being connected to the external signal processing unit 8. The capacitive
element 7 is a looped coil, made of a thin wire 14 which is wounded several times
on a free end 15. The other free end 16 of the wire 14 is connected to the connector
12.
[0028] Fig. 3 shows a cross-section along a line III-III of the seat 2, having a thickness
of 5 mm. As can be seen, the seat 2 comprises a seat body 17 made of one piece and
of a plastic material, e.g. polypropylene, acrylnitril-butadien-styrol, urea-formaldehyde
resin, a composite material, wood or a combination thereof. Note, that this enumeration
is not exhaustive. The wire 14, particularly its winding visible in fig. 3, is placed
on the surface of the seat body 17 within grooves and glued thereon. The seat body
17 and the capacitive element 7 are covered by an overlay 18 coating the side of the
seat body 17 on which the capacitive element 7 is arranged. The overlay 18 is painted
on the seat body 17.
[0029] Fig. 4 shows a block diagram of the sanitary device 1. The wire 14 is connected to
the signal processing unit 8 providing the seat occupancy information to the control
unit 9 which controls the functional components 13. In the unoccupied state of the
seat 2 the capacitive element 7 may be modeled by a capacitance C
Base being connected to ground. It has to be noted, that there is no mechanical connection
to an object realizing ground potential, but that the wire 14 is a capacitor structure
which forms a capacitor with a virtual capacitor structure on ground potential in
the environment of the wire 14 having the total capacitance C
total = C
Base.
[0030] When an object, particularly the body of a person taking seat, with a relative permittivity
significantly greater than 1 approaches the capacitive element 7 or the wire 14, respectively,
its total capacitance C
total increases. This is modeled by an additional capacitance C
Body connected in parallel to the capacitance C
Base and two coupling capacitances C
x and C
f. In practice, the capacitances C
x and C
f have only a small influence on the total capacity, which can thus be approximated
by C
total ≈ C
Base + C
Body > C
Base in the occupied state of the seat 2.
[0031] The signal processing unit 8 is adapted to apply a rectangular current to the capacitive
element 7, which charges and discharges it, and to measure a voltage U
m dropping over the capacitive element 7. During one pulse of the rectangular current
with a constant intensity I
S the voltage U
m increases linearly with the time. This can be modeled by the term

[0032] Thus, U
m increases faster in the unoccupied state of the seat 2 than in the occupied state,
since C
total is lower in the unoccupied state than in the occupied state.
[0033] Fig. 5 shows time curves of the voltage U
m measured while a test process, in which a constant current is applied to the capacitive
element 7 for 3 µs. As can be seen in the left curve showing the unoccupied state
of the seat 2, the voltage U
m increases up to 4,4 V. By contrast, in the occupied state the voltage U
m only increases up to 3,2 V, making it possible for the signal processing unit 8 to
clearly distinguish both occupancy states of the seat 2 by evaluating the voltage
U
m. Basing on this evaluation result, the signal processing unit 8 determines the occupancy
information which is provided to the control unit 9. Therefore, the signal processing
unit 8 compares the measured voltage U
m with a threshold value U
th which may be chosen to 4,0 V, whereby the seat 2 is assumed to be occupied if U
m < U
th. Note, that the specific voltage values refer to an exemplary configuration and may
be different in other configurations of the capacitive element 7. In practice, the
threshold value is saved in a memory of the signal processing unit 8. According to
other embodiments, the threshold value may be derived from a user input into an input
device of the sanitary device 1 describing a desired sensitivity of occupancy sensing.
[0034] Depending on the occupancy information provided by the signal processing unit 8 the
control unit 9 activates and deactivates the functional competence 13. E.g. if the
occupancy information indicates, that the seat 2 is no longer occupied, the control
unit 9 activates the flushing unit, activates the movement device to close the lid
4 and activates the deodorization unit. On the contrary, if the occupancy information
indicates the seat 2 being occupied, the control unit 9 will activate the heating
unit, the spraying unit and the blowing unit. Particularly, the heating unit is deactivated
when the seat 2 is detected to be unoccupied again. Of course, other conditions may
be considered by the control unit 9 when controlling the functional components 13.
[0035] Fig. 6 shows a cross-section of the further embodiment of the seat 2 which differs
from fig. 3 in that, grooves in the seat body 17 are omitted and the overlay 18 surrounds
the wire 14. Additionally, the overlay 18 coats the entire circumference of the seat
body 17.
[0036] Fig. 7 shows a top view on a further embodiment of the seat 2 which differs from
fig. 2 in that the capacitive element is a capacitive foil glued or laminated on the
seat body 17.
[0037] Fig. 8 shows a top view on a further embodiment of the seat 2 which differs from
fig. 2 in that the capacitive element 7 comprises an a printed circuit realizing the
signal processing unit 8, as well. Thus, the signal processing unit is not arranged
within the service device 10, so that the occupancy information determined by the
seat-side signal processing unit 8 is provided to the control unit 9 directly via
the connector 12.
[0038] According to another embodiment, the capacitive element 7 is realized by laser direct
structuring on the seat body 17 or fixed by in-mold decoration at the seat body 17.
According to yet another embodiment, the overlay 18 is glued and/or plated and/or
laminated on the seat body 17. Therefore, the overlay 18 may be a foil.
[0039] According to another embodiment, the sanitary device 1 is a bidet, allowing a person
sitting on the seat 2 to wash his body.
1. Sanitary device seat, comprising a ring- or U-shaped seat body (17) and at least one
capacitive element (7) adapted to provide a sensing signal processible to a seat occupancy
information, characterized in that the capacitive element (7) is arranged at the seat body (17) and covered by an overlay
(18) coating the seat body (17).
2. Sanitary device seat according to claim 1, characterized in that the capacitive element (7) is or comprises a looped coil and/or a capacitive foil
and/or a printed circuit and/or is realized by laser direct structuring.
3. Sanitary device seat according to claim 1 or 2, characterized in that the capacitive element (7) is glued and/or fixed by in-mold-decoration at the seat
body (17) and/or fixed by the coating.
4. Sanitary device seat according to one of the preceding claims, characterized in that the seat body (17) is made of one piece.
5. Sanitary device seat according to one of the preceding claims, characterized in that it has a thickness of at most 10 mm.
6. Sanitary device seat according to one of the preceding claims, characterized in that the overlay (18) is painted and/or glued and/or plated and/or laminated on the seat
body (17).
7. Sanitary device seat according to one of the preceding claims, characterized in that the seat body (17) is made from a plastic material, particularly comprising polypropylene
and/or acrylnitril-butadien-styrol and/or urea-formaldehyde resin, and/or a composite
material and/or wood.
8. Sanitary device, comprising a sanitary device seat (2) according to one of the preceding
claims.
9. Sanitary device according to claim 8, characterized in that a signal processing unit (8) is adapted to determine the seat occupancy information
depending on the sensing signal.
10. Sanitary device according to claim 9, characterized in that the signal processing unit (8) is adapted to apply an alternating, particularly rectangular
or trapezoidal, current to the capacitive element (7).
11. Sanitary device according to claim 9 or 10, characterized in that the signal processing unit (8) is adapted to measure a voltage dropping over the
capacitive element (7) as the sensing signal.
12. Sanitary device according to one of the claims 9 to 11, characterized in that the signal processing unit (8) is disposed outside the sanitary device seat (2) or
arranged between the seat body (17) and the overlay (18).
13. Sanitary device according to one of claims 8 to 12, characterized in that a control unit (9) is adapted to control at least one functional component (13) of
the sanitary device (1) depending on the occupancy information.
14. Sanitary device according to claim 13, characterized in that the functional component (13) is or comprises a spraying unit adapted to spray a
liquid towards a human body sitting on the sanitary device seat (2) and/or a blowing
unit adapted to blow air towards a human body sitting on the sanitary device seat
(2) and/or a heating unit adapted to heat the sanitary device seat (2) and/or a flushing
unit and/or a movement device adapted to close a lid (4) of the sanitary device (1)
and/or a deodorization unit.
15. Sanitary device according to one of the claims 9 to 14, characterized in that a service device (10) is arranged separately from the sanitary device seat (2) and
incorporating the control unit (9) and/or the signal processing unit (8), which is
disposed outside the sanitary device seat (2), in a housing.