JP2000241366A - Moisture detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a moisture detecting device by which moisture can be detected with good accuracy without applying a burden on a person on whom an object, to be moisture-detected, such as a diaper or the like is placed. SOLUTION: This moisture detecting device is provided with a resonating body 1 in which a resonance circuit composed of a coil pattern and a capacitor pattern is installed at an insulator and which generates reflected radio waves 1b when it exists in a dry state in a place in which transmitting radio waves 23b at a resonance frequency are transmitted. In addition, the moisture detecting device is provided with a transmitter-receiver 2 which transmits the transmitting radio waves 23b to the place, which performs a receiving operation in synchronization with their transmission and which detects moisture on the basis of the receiving intensity of residual radio waves 1b received after the transmission of the transmitter-receiver 2 is stopped. The moisture detecting device is constituted in such a way that the resonating body 1 is placed on an object, to be moisture-detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture detecting device for detecting moisture contained in a moisture detecting object such as a disposable diaper.

[0002]

2. Description of the Related Art Conventionally, as this type of moisture detecting device, for example, JP-A-10-057412 and JP-A-10-030.
998 and JP-A-9-304312. This thing, both electrodes that are energized by the adhesion of moisture, a battery that energizes both electrodes, an electronic circuit unit that detects the energization between both electrodes, a connection cord that connects between the electrodes and the electronic circuit unit, A notification device that is connected to the electronic circuit unit and notifies the energization detection to the outside.

[0003]

In the above-mentioned conventional moisture detecting device, the presence or absence of moisture adhering between the two electrodes can be detected by detecting the conduction between the two electrodes.

[0004] However, when the cared person is mounted on a diaper to be used, both electrodes, a battery, an electronic circuit section,
In addition, the size and the size of the notification device are increased, and both electrodes are connected to the electronic circuit section by the connection cord, so that they become an obstacle for the cared person and become a burden. further,
There was a case where a report was lost due to battery exhaustion.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the water content of a moisture detection object without burdening a person wearing the moisture detection object such as a diaper. An object of the present invention is to provide a moisture detecting device capable of detecting with high accuracy.

[0006]

According to a first aspect of the present invention, there is provided a resonance circuit including a coil pattern and a capacitor pattern provided on an insulating sheet, and a transmission radio wave having a resonance frequency is transmitted. A resonator that generates reflected radio waves when it is in a dry state in the field, and transmits transmission radio waves to the field and performs reception operation in synchronization with transmission,
And a transceiver for detecting moisture based on the received radio wave characteristics obtained from the received radio waves including the reflected radio waves, wherein the resonator is mounted on the moisture detection target.

According to a second aspect of the present invention, in the first aspect, the received radio wave characteristic is a reception intensity of a residual radio wave received after transmission of the transceiver is stopped.

According to a third aspect of the present invention, in the first or the second aspect, a radio frequency noise having a constant frequency exists in the field, and the transceiver is configured so that the resonance frequency excluding the constant frequency is removed. Is transmitted.

According to a fourth aspect of the present invention, in the third aspect, a plurality of the resonators that resonate at the different resonance frequencies are provided, and the transceiver sets a frequency so as to transmit a transmission radio wave of each of the resonance frequencies. It is configured to switch.

A fifth aspect of the present invention is the paper diaper according to any one of the first to fourth aspects, wherein the moisture detecting object is a paper diaper to be worn on a person, and the resonator is previously formed on the paper diaper. It is configured in a thin sheet shape so that it can be mounted.

[0011]

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

Reference numeral 1 denotes a resonator, which is formed in a thin sheet shape.
As shown in FIGS. 2 to 5, a film-like insulating sheet 11 made of paper or resin having a specific dielectric constant, a coil pattern 12 formed on both sides of the insulating sheet 11 and conducting with each other at the center. Similarly, a capacitor pattern 13 formed on both sides of the insulating sheet 11 and connected to the coil pattern 12 is provided. The coil pattern 12 is Al,
The coil component is formed in a spiral shape by a thin-film metal such as Cu, Au, or Ag, and the capacitor pattern 13 is similarly formed in a rectangular shape by the thin-film metal. A capacitance component is formed by sandwiching both sides. Then, a resonance circuit having a resonance frequency characteristic is formed by the coil pattern 12 and the capacitor pattern 13, and generates a reflected radio wave when in a dry state when the transmission radio wave 23b of the resonance frequency is present in a transmitting place. However, when the coil pattern 12 and / or the capacitor pattern 13 is short-circuited by moisture in a wet state instead of a dry state, it does not resonate and does not generate reflected radio waves.

Here, the resonance frequency f of the resonance circuit is designed by the following equation, and the number of turns of the coil pattern 12, the area of the capacitor pattern 13, and the insulating sheet 1
It is uniquely determined by the thickness of 1.

F = 1 / [2π√ (LC)] (Equation 1) The Q value of the resonance circuit is calculated by the following equation (2).
It is set to 50 to 100 or more, and harmonics are not considered.

Q = ωL / R (Equation 2) 2 is a transceiver, a CPU 21 for controlling the whole, and a CPU
21, a transmission unit 23 connected to the timing signal output unit 22 and provided with a transmission antenna 23a, and a reception unit 24 connected to the timing signal output unit 22 and provided with a reception antenna 24a. A computing unit 25 connected to the transmitting unit 23 and the receiving unit 24;
21 and an output unit 26 connected to the output unit 21. In each transceiver 2, the transmitting antenna 23a and the receiving antenna 24a are formed on the same plane.

A timing signal output section 22 outputs a signal at a fixed timing, and a transmission section 23 generates a transmission radio wave 23b having a resonance frequency at a transmission antenna 23a based on the timing signal, and transmits the transmission radio wave 23b to a field. I do.
In addition, while the transmission of the transmission radio wave 23b is stopped, the reception unit 24 operates in synchronization with the signal from the timing signal output unit 22, and receives the reception radio wave including the reflection radio wave generated by the resonance circuit of the resonator 1. The signal is received and amplified by the receiving antenna 24a. After the calculation unit 25 stops the transmission radio wave 23b, the reception intensity of the residual radio wave 1b output from the resonator 1 is measured to obtain the reception radio wave characteristic, and the measurement result of the reception radio wave characteristic is obtained by the CPU.
Give to 21. This will be described later in detail.

Reference numeral 3 denotes a notification device, which is provided with a display unit 31 such as a CRT and a notification sound generation unit 32 for generating a notification sound. 2 stores the installed personal information.

The operation of this embodiment will be described with reference to FIGS. The resonator 1 resonates at different resonance frequencies.
As shown in FIG. 6, each resonator 1 is previously mounted on the center of a disposable diaper 1a attached to a care receiver (person), and the disposable diaper 1a forms a moisture detection target.

As shown in FIG. 7, the transmitter / receiver 2 has a transmitting antenna 23a and a receiving antenna 24a formed on the same plane, and is mounted on a bed 4 on which a care receiver wearing a disposable diaper 1a is lying down. The place is bed 4
And a radio wave noise of a constant frequency exists in the field. As shown in FIG. 8A, a transmission radio wave 23b having a different resonance frequency consisting of CH (channel) 1 to CH10 corresponding to the resonance frequency of each resonator 1 is generated. Then, by appropriately selecting and switching the resonance frequency from CH1 to CH10, the transmission antenna 2
3a transmits the transmission radio wave 23b of the resonance frequency excluding the constant frequency of the radio noise to the place formed by the bed 4.

Here, the transmission radio wave 23 transmitted on each CH
Continuously variable (analog type) before and after the resonance frequency of the resonator 1 assumed in design so that b corresponds to the variation of the resonance frequency due to the manufacturing variation and the shape change of the resonator 1.
Instead, it varies the frequency with discrete values. For example, if the frequency is in the 5 MHz band,...
98 MHz, 4.99 MHz, 5.00 MHz, 5.0
0.01 MHz, such as 1 MHz, 5.02 MHz, etc.
Variable at every z. Further, each CH is constituted by spots having a constant (frequency-dependent) frequency width, and FIG.
As shown in FIG. 7, for example, 17 spots (f
10, f11,... F116).

Then, the transmission section 23 operates based on the timing signal shown in FIG. 9A output from the timing signal output section 22, and is defined for each spot as shown in FIG. 6B. The above-mentioned transmission radio waves 23b shown in FIG. 6D are sequentially emitted from the transmission antenna 23a to the field.

When the transmission wave 23b is being transmitted and the resonator 1 is in a dry state, after the transmission of the transmission radio wave 23b is stopped, the resonator 1 has a duration of P2 compared to the duration P1 of the transmission radio wave 23b. When a long reflected radio wave is generated,
A residual radio wave 1b shown in (f) is formed. On the other hand, the coil pattern 12 or the capacitor pattern 1
In a wet state where 3 is short-circuited by moisture, no reflected radio wave, that is, no residual radio wave 1b is generated.

Next, as shown in FIG. 6C, in the transceiver 2, the receiving unit 24 performs a receiving operation based on the timing signal, receives the received radio wave including the reflected radio wave, and transmits the transmitted radio wave from the transmitting unit 23. After stopping 23b, the calculation unit 25 measures the reception intensity of the residual radio wave 1b (duration P2) in a dry state of the resonator 1 based on the reception radio wave, and
Give to U21. On the other hand, in the wet state of the resonator 1, FIG.
As shown in (e), the residual radio wave 1b is not received.

Next, the CPU 21 uses the received radio wave characteristic of the residual radio wave 1b given from the arithmetic unit 25 to
The presence or absence of moisture in a is detected. That is, if the reception intensity of the residual radio wave 1b for each spot is equal to or more than a predetermined value and the reception intensity is compared with the characteristic of each spot stored in advance for the selected CH and is within a certain allowable value, the residual radio wave It is determined that 1b has been detected. Then, it is determined that the resonator 1 is present in the field and is in a dry state without any abnormality, and does not output the moisture detection information to the output unit 26. Further, when the intensity characteristic is less than a predetermined value and the residual radio wave 1b
Is not detected, it is determined that the resonator 1 does not exist in the field, or that moisture does not adhere to and penetrate the resonator 1 to form a resonance circuit. Further, when the resonator 1 is installed so as to be always present in the field, the CPU 21
The undetected state of the diaper 1a continues for a certain period of time, so that the disposable diaper 1a
It is determined that the moisture in the water is detected, that is, it is determined that the care receiver wearing the disposable diaper 1a has excreted, and outputs the moisture detection information to the notification device 3 via the output unit 26.

Next, based on the stored personal information, the notification device 3 displays on the display unit 31 such as a CRT that excretion has been performed, and the notification sound generation unit 32 generates a notification sound to provide the care staff. Notify.

In the moisture detecting apparatus according to the embodiment, as described above, the transceiver 2 detects moisture based on the received radio wave characteristics obtained from the received radio waves including the reflected radio waves generated from the resonator 1. Therefore, when the transmitter / receiver 2 transmits the transmission radio wave 23b having the resonance frequency, the resonance circuit of the resonator 1 resonates with the transmission radio wave 23b in a dry state to generate a reflected radio wave, but is short-circuited by moisture instead of the dry state. A reflected radio wave is not generated in a wet state, and the received radio wave characteristic is changed depending on the presence or absence of moisture. Water can be easily attached to the detection target and moisture can be detected without putting a burden on a person who has mounted the moisture detection target.

Since the reception intensity of the residual radio wave 1b received after the transmission / reception of the transmitter / receiver 2 is stopped is defined as the reception radio wave characteristic, the transmitter / receiver 2 transmits the residual radio wave 1b
, The presence or absence of moisture in the resonator 1 can be accurately detected.

Further, since the transceiver 2 transmits a resonance frequency excluding a certain frequency of the radio noise, it is possible to accurately detect the presence or absence of moisture without being disturbed by the radio noise.

Further, since a plurality of resonators 1 resonating at different resonance frequencies are provided, and the transceiver 2 transmits the transmission radio wave 23b of each resonance frequency by switching the frequency, even if the constant frequency of the radio noise is different. Also, even if a plurality of fixed frequencies exist, it is possible to easily cope with radio wave noise existing in the field.

Further, since the resonator 1 is formed in a thin sheet shape and is previously mounted on the disposable diaper 1a, the operation of attaching the resonator 1 every time the disposable diaper 1a is replaced is eliminated, thereby reducing the burden on the diaper care of the caregiver. be able to.

In this embodiment, the received radio wave characteristic is defined as the reception intensity of the residual radio wave 1b, and the moisture is detected based on the received intensity. However, the received radio wave characteristic may be, for example, a change in the intensity of the reflected radio wave. There is no particular limitation as long as the value is obtained based on the received radio wave including.

Further, in this embodiment, a plurality of resonators 1 resonating at different resonance frequencies are provided, and the transceiver 2 transmits the transmission radio waves 23b of each resonance frequency except for a certain frequency of radio noise.
Is transmitted, but when radio wave noise does not exist in the field, the transmission radio wave 23b having a predetermined resonance frequency is transmitted, and there is no limitation.

Further, in the present embodiment, the object of moisture detection is the disposable diaper 1a worn by a person. However, the present invention is not limited to the disposable diaper 1a, and the disposable diaper 1a may be attached to an animal, for example. Not done.

[0034]

According to the first aspect of the present invention, since the transceiver detects moisture based on the reception radio wave characteristic obtained from the reception radio wave including the reflected radio wave generated from the resonator, the transmission / reception device has the resonance frequency. When a radio wave is transmitted, the resonance circuit of the resonator resonates with the transmitted radio wave in a dry state and generates a reflected radio wave, but does not generate a reflected radio wave in a wet state where it is short-circuited with moisture but not in a dry state, and depending on the presence or absence of moisture By changing the characteristics of the received radio wave, it is possible to detect the moisture after attaching the resonator easily without burdening the moisture detection target without the need for wiring between the resonator and the transceiver and a battery. it can.

According to the second aspect, in addition to the effect of the first aspect, the reception intensity of the residual radio wave received after the transmission of the transceiver is stopped is set as the reception radio wave characteristic.
The transceiver can detect the presence / absence of residual radio waves generated from the resonator and accurately detect the presence / absence of moisture in the resonator.

According to the third aspect, in addition to the effects of the first or second aspect, if radio wave noise of a certain frequency is present in the field, the transmitter and the receiver excluding the certain frequency can be used for resonance. Since the frequency is transmitted, the presence / absence of moisture can be accurately detected without being disturbed by radio wave noise.

According to a fourth aspect of the present invention, in addition to the effect of the third aspect, a plurality of resonators which resonate at different resonance frequencies are provided, and the transceiver switches the frequency and transmits the transmission radio wave of each resonance frequency. Therefore, even if the constant frequency of the radio noise is a different frequency or a plurality of constant frequencies exist, it is possible to easily cope with the radio noise existing in the field.

According to a fifth aspect, in addition to the effects of the first aspect, if the moisture detection target is a paper diaper to be worn by a person, the sheet having a thin resonator is provided. Since it is formed in a shape and is attached to the disposable diaper in advance, the operation of attaching the resonator every time the disposable diaper is replaced can be eliminated, and the burden on the caregiver of the diaper can be reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a front view of the resonator according to the first embodiment;

FIG. 3 is a rear view of the resonator according to the first embodiment;

FIG. 4 is a cross-sectional view (XX cross-sectional view in FIG. 2) of the resonator according to the first embodiment;

FIG. 5 is a sectional view of the resonator (a sectional view taken along line YY in FIG. 2);

FIG. 6 is a front view of the disposable diaper to which the resonator is mounted.

FIG. 7 is a perspective view showing a usage example of the above.

FIG. 8A is a channel diagram of a transmission radio wave having each resonance frequency, and FIG. 8B is a spot division diagram in each channel.

FIG. 9 is a timing chart illustrating the operation of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resonator 11 Insulating sheet 12 Coil pattern 13 Capacitor pattern 1a Disposable diaper 1b Residual radio wave (reflected radio wave) 2 Transceiver 23b Transmitted radio wave 3 Notification device 4 Bed (field)

Claims (5)

[Claims] 1. A resonator which generates a reflected radio wave when a resonance circuit including a coil pattern and a capacitor pattern is provided in an insulating sheet in a dry state where a transmission radio wave of a resonance frequency is transmitted, and a transmission radio wave in the field And a receiver that performs reception operation in synchronization with transmission and detects moisture based on received radio wave characteristics obtained from received radio waves including reflected radio waves, and attaches the resonator to the moisture detection target object. A moisture detecting device, comprising: 2. The moisture detecting device according to claim 1, wherein the received radio wave characteristic is a reception intensity of a residual radio wave received after the transmission of the transceiver is stopped. 3. A radio wave noise of a certain frequency is present in a field, and the transceiver transmits a radio wave of the resonance frequency excluding a certain frequency. The moisture detection device according to any one of the preceding claims. 4. The moisture detecting device according to claim 3, wherein a plurality of the resonators that resonate at the different resonance frequencies are provided, and the transceiver switches a frequency so as to transmit a transmission radio wave of each of the resonance frequencies. . 5. The disposable diaper according to claim 1, wherein the moisture detecting target is a disposable diaper to be attached to a person, and the resonator is formed in a thin sheet shape so that the disposable diaper can be attached to the disposable diaper in advance. 5. The moisture detecting device according to any one of 4.