JPH05293059A - Toilet seat sitting position sensor - Google Patents

Abstract

PURPOSE:To provide a toilet seat sitting position sensor that does not generate an error in detection even when the quantity of electrification is controlled. CONSTITUTION:A toilet seat 1 stores a heater 2 whose temperature is adjusted by the control of the quantity of electrification. The electrode 5b of a capacitor 5 for detection and the electrode 6b of a reference capacitor 6 respectively form a delay element. A pulse generating circuit 7 inputs pulse to both delay circuits 8 and 9. A phase discrimination circuit 12 identifies the sitting position of man on a toilet seat. Consequently, change in the capacity of the detection capacitor and that of reference capacitor due to change in the amount of electricity supplied to a heater 2 are offset thereby giving no influence upon the output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seating sensor for detecting seating of a person on a seating object such as a toilet seat, a chair, and a cushion having a seating portion in which a heater is built in.

[0002]

2. Description of the Related Art Conventionally, it is known that a toilet seat 1 having a shape as shown in FIG. 2 has a heater 2 built therein as shown in FIGS. It is also possible to provide a seating sensor for detecting the seating of the person on the toilet seat 1 in order to energize the heater 2 and enable the local washer only while the person is seated on the toilet seat 1. Has been. Various seating sensors are known that detect seating (or approach) of a person based on a change in capacitance. For example, as shown in FIG. 3 and FIG.
The plate-shaped electrode 3 also serving as the heat diffusion plate is provided, and an electrode (not shown) that constitutes the detection capacitor together with the electrode 3 is provided, so that when the human body A approaches as shown in FIG. There is a device which detects a person's sitting by detecting a capacitance change of a detection capacitor.

[0003]

By the way, in the above structure, since the heater 2 is disposed in the vicinity of the electrode 3, if the amount of electricity to the heater 2 is controlled in order to control the temperature of the heater 2 (for example, , The temperature is controlled by intermittently energizing), the electric field around the electrode 3 changes, and the capacitance of the detection capacitor changes. Therefore, when a person is seated, it may be determined that the person is not seated due to a change in the amount of electricity supplied to the heater 2, and a malfunction may occur. Further, in the case where the heater 2 is energized before a person is seated, it may be determined that the person is seated even if the person is not seated, and malfunction may occur.

An object of the present invention is to solve the above-mentioned problems and to provide a seating sensor which does not cause erroneous detection even when the amount of electricity supplied to the heater is controlled.

[0005]

In order to achieve the above object, the present invention provides a seating object having a seating portion in which a heater is built in, the temperature of which is regulated by controlling the amount of energization, and a person is seated on the seating object. A detection capacitor in which an electrode is arranged in the seated object so that the capacitance changes as the person sits on the seated object, and a seated object that does not cause a capacitance change due to the person sitting on the seated object. A reference capacitor having electrodes arranged inside the object, a pair of delay circuits each having a detection capacitor and a reference capacitor as delay elements, a pulse generation circuit for inputting pulses to both delay circuits, and both delay circuits And a determination circuit for determining the seating of a person on the seated object based on the difference in the delay time of the pulse at, the electrode of the detection capacitor is disposed on the upper surface side of the seated object with respect to the heater, the reference Electrodes for capacitors It is what is disposed on the lower surface of the seating object to the heater.

[0006]

According to the above structure, the capacitance difference between the detection capacitor whose capacitance changes when a person sits on the seated object and the reference capacitor whose capacitance does not change depending on the person seated on the seated object is detected. By doing so, seating of a person can be detected with high sensitivity. The operating principle of this type of capacitance sensor for detecting the capacitance difference is disclosed in Japanese Patent Laid-Open No. 57-1499.
No. 11, for example. In the present invention, since the detection capacitor and the reference capacitor are arranged via the heater, if the energization amount of the heater is controlled, the capacitance of the detection capacitor and the reference capacitor will change to the same extent. Therefore, when the capacitance difference is detected, the capacitance change due to the change in the energization amount of the heater is canceled. As a result, erroneous detection due to the control of the energization amount of the heater can be prevented.

[0007]

EXAMPLE In this example, a toilet seat 1 as shown in FIG. 2 is illustrated as a seating object having a heater 2 incorporated therein. As shown in FIG. 1, the detection capacitor 5 and the reference capacitor 6
And. Detection capacitor 5 and reference capacitor 6
One of the electrodes 5a and 6a is disposed in the toilet seat 1 which is a synthetic resin molded product, and is connected to the ground line of the circuit section described later. The other electrodes 5b and 6b are formed in a flat plate shape and are embedded in the toilet seat 1 which is a synthetic resin molded product, as shown in FIG. 1 (b). The electrodes 5b and 6b are the heater 2
The electrodes 5b of the detection capacitor 5 are arranged so as to face each other with the heater 5 interposed therebetween so as to also serve as a heat diffusion plate for uniformly transmitting the heat of the heater 2 to the toilet seat 1. Also, the electrodes 5a, 6
a is commonly connected to form a capacitor together with the electrodes 5b and 6b, and is connected to a ground line of a circuit section described later.

The detecting capacitor 5 and the reference capacitor 6 serve as delay elements of the delay circuits 8 and 9, respectively. That is, each of the delay circuits 8 and 9 is a combination of a time constant circuit such as an RC integration circuit or an LC integration circuit and a well-known binarization circuit such as a comparator or a Schmitt circuit.
The output pulse is obtained by delaying the input pulse with a delay time corresponding to the capacities of the detection capacitor 5 and the reference capacitor 6, respectively. Each delay circuit 8, 9
A pulse from the pulse generation circuit 7 is input to the. Therefore, the output pulses of the delay circuits 8 and 9 have a time difference corresponding to the capacitance difference between the detection capacitor 5 and the reference capacitor 6. The outputs of the delay circuits 8 and 9 are passed through the delay adjustment circuits 10 and 11, respectively, and the phase discrimination circuit 1
Entered in 2. The delay adjustment circuits 10 and 11 adjust the offset value of the delay time of the output pulse of each delay circuit 8 and 9. In the phase discrimination circuit 12, both delay circuits 1
The difference in delay time between 0 and 11 (that is, the phase difference) is detected,
When the difference between the delay times exceeds a predetermined threshold value, it is determined that a person is seated and an output signal is generated. That is, the phase discrimination circuit 12 functions as a determination circuit.

By the way, the phase discrimination circuit 12 determines whether or not a person sits on the toilet seat 1 based on the capacitance difference between the detecting capacitor 5 and the reference capacitor 6. On the other hand, since the electrodes 5b and 6b of the detection capacitor 5 and the reference capacitor 6 are arranged so as to sandwich the heater 2, the capacitance change between the detection capacitor 5 and the reference capacitor 6 due to the change in the energization amount of the heater 2. Are almost equal. Therefore, in the phase discrimination circuit 12, the capacitance change due to the energization amount of the heater 2 is canceled out and is not detected, so that erroneous detection does not occur. The electrode 6b of the reference capacitor 6 is
Since it is arranged on the opposite side of the electrode 5b of the detection capacitor 5 with the heater 2 interposed therebetween, the change of the electric field due to the approach of a person mainly occurs in the detection capacitor 5, and the reference capacitor 6 almost does not. It has no effect.
Therefore, the reference capacitor 6 does not cause a capacitance change due to sitting of a person, and can be used as a reference for the detection capacitor 5.

[0010]

As described above, the present invention includes a detection capacitor which causes a capacitance change due to a person sitting on an object to be seated.
There is an advantage that the seating of a person can be detected with high sensitivity by detecting the capacitance difference from the reference capacitor whose capacitance does not change depending on the seating of the person on the seated object. In addition, since the detection capacitor and the reference capacitor are arranged via the heater, if the energization amount of the heater is controlled, the detection capacitor and the reference capacitor will change to the same extent and the capacitance difference will occur. When this is detected, the capacitance change due to the change in the energization amount of the heater is offset. As a result, it is possible to prevent erroneous detection due to the control of the energization amount of the heater.

[Brief description of drawings]

FIG. 1 shows an embodiment, (a) is a sectional view of a main part, and (b) is a block circuit diagram.

FIG. 2 is a perspective view showing an example of a toilet seat to which the present invention is applied.

FIG. 3 is a schematic plan view showing a conventional example.

FIG. 4 is a sectional view of a main part showing a conventional example.

FIG. 5 is a principle explanatory view showing a conventional example.

[Explanation of symbols]

 1 Toilet Seat 2 Heater 5 Detection Capacitor 5a, 5b Electrode 6 Reference Capacitor 6a, 6b Electrode 7 Pulse Generation Circuit 8 Delay Circuit 9 Delay Circuit 12 Phase Discrimination Circuit

Claims (1)

[Claims] 1. A seating object having a seating part for seating a person and having a heater whose temperature is controlled by controlling the amount of energization, and a capacity of the seating object that changes as the person sits on the seating object. A detection capacitor with an electrode inside the seated object, a reference capacitor with an electrode inside the seated object so that the capacitance does not change when a person sits on the seated object, and a detection capacitor. A pair of delay circuits each having a capacitor and a reference capacitor as delay elements, a pulse generation circuit for inputting pulses to both delay circuits, and a seating object based on the difference in pulse delay time between both delay circuits A determination circuit for determining whether a person is seated, the electrode of the detection capacitor is disposed on the upper surface side of the seating object with respect to the heater, and the electrode of the reference capacitor is disposed on the lower surface side of the seating object with respect to the heater. Being arranged Seating sensor characterized by.