JPH0572349A - Human body detector for bath tub - Google Patents

Abstract

(57) [Summary] [Purpose] To detect the human body in the bathtub and the water level. An electrode 2 having a required length in the height direction of the outer wall 5 is attached to the outer wall 5 of the bathtub 4, and the electrode 2 is attached to the electrode 2.
The oscillation circuit 3 whose oscillation output is determined by the capacitance formed therebetween is connected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a human body detecting device for a bathtub which can detect the presence or absence of a person in the bathtub and the water level of the bathtub.

[0002]

2. Description of the Related Art Conventionally, there is no optimum means for detecting the presence or absence of a person in a bathtub, and there is a push button switch provided on the wall surface of a bathroom for emergency notification. When an abnormality occurs in the bathroom, this switch pushes the button to inform the outside of its existence.

[0003]

However, in the above push button switch, for example, when a brain ikette or the like is raised in the bathtub and the freedom of the hand is robbed, the push button switch is not pushed to the outside. I can't let you know.

[0004]

In order to solve the above problems, two flat plate electrodes are provided in a bath at a predetermined interval, and the oscillation output is determined by the capacitance formed between the electrodes on the electrodes. The circuit is connected.

At this time, the electrode may be provided along the side wall of the bath, and the electrode on the side wall may be elongated in the height direction of the side wall.

Since the plate electrode interval determines the detection sensitivity, it is appropriately determined by experiments or experience.

[0007]

The human body detecting device for a bathtub configured as described above is
The capacitance formed between the electrodes changes due to the change in the permittivity of the water contained in the bath and the permittivity when a human body enters the bath containing the water. , The oscillation frequency and the amplitude level of oscillation change.

Further, in the case where the electrode is provided long along the side wall of the bath in the height direction, the change of the water level is detected as the change of the capacitance, and the oscillation frequency and the amplitude level of the oscillation change.
Now, for ease of explanation, consider a case where the electrodes are provided so as to face each other.

That is, the distance between the electrodes provided facing each other is d, the height of the electrode is H, the width of the electrode is 1, the dielectric constant of vacuum is ε ₀ , the dielectric constant of air is εr ₁ , and the dielectric constant of water is When εr ₂ is set and the height h ₁ is filled between the electrodes, the capacitance between the electrodes becomes

[0010]

[Equation 1]

[0011] At this time, since capacitances other than the water level h ₁ are constants, the capacitance c is determined by the height of the water level h ₁ . Here, c ₁ is the capacitance between the electrodes from the height h ₁ to H of the electrodes, and c ₂ is the capacitance between the electrodes from the height h ₁ of the electrodes.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a bathtub human body detection device (hereinafter referred to as a sensor) 1 comprises two electrode plates 2 and an oscillation circuit 3 connected to the electrode plates 2, and an outer wall 5 of a bathtub 4 is provided. It is provided in.

Both electrode plates 2 are, as shown in FIG.
Along the outer wall 5 of the sheet, the sheets are attached at predetermined intervals. Both electrodes 2 have a required length in the height direction of the outer wall 5.

For the electrode plate 2, a metal plate such as an iron plate, a copper plate, an aluminum plate, or a conductive film can be used.

As shown in FIG. 3, the oscillating circuit 3 comprises, for example, the electrode plate 2, the coil 10 and the transistor 11. The electrode plate 2 is connected in parallel to the coil 10 and a transistor LC oscillator is connected. Is forming. Therefore, the oscillation frequency and the oscillation amplitude level of the oscillation circuit 3 are determined by the tank circuit formed by the both electrode plates 2 and the coil 10. Therefore, when water or a person enters the bathtub 4, the dielectric constant between the electrode plates 2 changes, the capacitance changes, the resonance frequency of the tank circuit changes, and the oscillation frequency and oscillation of the oscillation circuit 3 change. The amplitude level changes.
As described above, the sensor 1 detects the change in the capacitance between the electrodes caused by the change in the dielectric constant when water or a person enters the bathtub 4, and does not use any moving parts. Excellent and extremely few failures.

Now, the output of the oscillation circuit 3 was detected, the oscillation output was converted into a DC voltage, and the output voltage was measured by the following procedure. The measurement result will be described with reference to the schematic diagram shown in FIG.

When there is nothing in the bath 4, the output voltage shows a constant voltage state (a). When water was started to be poured into the bathtub 4, the sensor 1 detected the shaking (b) of water, and the output voltage thereof dropped (c) according to the water level. When the bath 4 became full (d) and the water level became higher than the electrode plate 2, the sensor 1 did not detect the fluctuation of the water level, and the output voltage became constant (e). In this state, when a person enters the bathtub 4, the sensor 1
Detected a difference in the dielectric constant between water and the human body, and the output voltage dropped (f). At this time, when a person moved in the bathtub 4, the output voltage fluctuated due to the positional relationship between the person and the electrode plate 2 (g). Next, when a person exits the bathtub 4, the output voltage becomes a voltage close to a full-filled state again, and the sensor 1 detects shaking of water (h). When the shaking of the water stopped, the voltage became constant (re).

Thus, the sensor 1 can detect the presence of a person in the bathtub 4 and the water level of the bathtub at the same time.

Therefore, the hot water temperature can be controlled by the output of the sensor 1.

Generally, a person begins to enter the bathtub 4 and feels a high temperature, so that the hot water temperature at the time of hot water supply is set to be low,
The sensor 1 detects that a person has entered the bathtub 4,
A reheating command can be issued.

Further, the time during which the output of the sensor 1 detects the presence of a person in the bathtub 4 is measured, and if the measured time exceeds a certain time, it is judged that an abnormality has occurred in the bathtub 4, and an abnormal signal is given. It may be issued and the information may be notified to the outside.

Further, since the water level can be detected, it is optimal as a sensor for a hot water supply system, and can also be used as a sensor for managing water supply and hot water supply.

The electrode plate 2 may be provided not only on the outer wall 5 of the bathtub, but also on the inner wall of the bathtub 4 after the surface of the electrode 2 is waterproofed and insulated. Further, the installation location may be provided inside or outside the bottom of the bathtub 4. Further, the electrode plate 2 may be embedded in the bath 4.

Further, a bathtub human body detection device capable of detecting a human body in the bathtub is provided in the bathroom, and a human body detection sensor previously proposed by the applicant of the present application in Japanese Patent Application No. 2-24197 is provided in the washroom. By providing it, it is possible to detect the human body in the entire bathroom and prevent accidents while taking a bath.

Further, the device capable of detecting the human body in the entire bathroom as described above is most suitable for use as a sensor for home security or an emergency call system to the outside.

[0027]

The present invention is configured as described above and detects the oscillating frequency and the amplitude level of the oscillation due to the capacitance change between the electrodes, so that the human body in the bath can be always detected.

Further, in the case where the electrodes are provided long along the side wall of the bath in the height direction, at the same time when the human body in the bath is detected,
It is also possible to detect continuous changes in water level within the required length of the electrode.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment.

FIG. 2 Action diagram

[Fig. 3] Circuit diagram

[Explanation of symbols]

 1 Human Body Detector for Bath 2 Plate Electrode 3 Oscillation Circuit 4 Bath 5 Outer Wall

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kiyoshi Kamio 1-23-19 Asahi-cho, Machida-shi, Tokyo Tokyo Electrotechnical Lab. (72) Inventor Masayoshi Kishikawa 3-7 Honami-cho, Suita-shi, Osaka No. FB Otome Co., Ltd.

Claims (2)

[Claims] 1. A human body detecting device for a bathtub, wherein two flat plate electrodes are provided at a predetermined interval in a bathtub, and an oscillation circuit whose oscillation output is determined by a capacitance formed between the electrodes is connected to the electrodes. 2. The bath sensor according to claim 1, wherein
The human body detection device for a bathtub, wherein the electrode is provided along the side wall of the bathtub, and the electrode on the side wall is elongated in the height direction of the side wall.