JPH04254783A - Electromagnetic coupling communication apparatus - Google Patents

Abstract

PURPOSE:To discriminate the state change of a part to be detected while making an echo detecting surplus time and an echo detectable distance long by simple constitution. CONSTITUTION:An electromagnetic coupling communication apparatus 10 consists of a main apparatus 20 and the sensor apparatus 30 arranged at the specific position of the building isolated from the main apparatus 20 and the sensor apparatus 30 has an antenna 31 receiving the monitoring frequency signal from a signal generating part 21 by electromagnetic coupling and transmitting the echo resonated with said signal to the main apparatus 20 and the resonance circuit corresponding to the monitoring frequency signal from the signal generation part 21. In this apparatus 10, the resonance circuit of the sensor apparatus 30 has an LCX parallel resonance circuit consisting of the antenna 31, a condenser 32 and a solid-state vibrator and an echo state altering means changing the LC resonance frequency of the LCX parallel resonance circuit with respect to the resonance frequency of X on the basis of the state change of the part to be detected and altering the state of an echo to the monitoring frequency signal by changing Q of the resonance frequency of X.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic coupling communication device suitable for forming a window intrusion sensing device or the like.

0002

2. Description of the Related Art Conventionally, a window intrusion sensing device as described in Japanese Patent Application Laid-Open No. 62-27891 has been proposed. This window intrusion sensing device uses an LC resonant circuit, and the frequency of the echo from the LC resonant circuit changes as the window opens and closes relative to the window frame.

0003

However, the prior art has the following problems (1) and (4).

(2) Since changes in the state of the detected part are identified by variations in the echo frequency, the configuration is complicated.

■Since the echo of the LC resonant circuit has a small Q (resonance sharpness), the echo duration is short, and as a result,
Echo detection margin time is short. Furthermore, when using detectors that require the same amount of time to detect echoes, the echo detectable distance must be shortened.

SUMMARY OF THE INVENTION It is an object of the present invention to make it possible to identify changes in the state of a detected portion while increasing the echo detection margin time and the echo detectable distance using a simple configuration.

[0007]

[Means for Solving the Problems] The present invention as set forth in claim 1 comprises a main device and a sensor device placed at a specific position in a building remote from the main device, and the main device has a sensor device for specific monitoring purposes. a signal generator that generates a frequency signal; a detector that detects the state of the echo from the sensor device; and a detector that transmits the signal generated by the signal generator to the sensor device and receives the echo from the sensor device by electromagnetic coupling. 1 antenna, a changeover switch that selectively connects each of the signal generation section and the detection section to the first antenna, a control section that switches the changeover switch to the signal generation section and the detection section at a constant cycle, and a detection section. and a display section for displaying the detection results of the section,
The sensor device includes a second antenna that receives the monitoring frequency signal from the signal generator through electromagnetic coupling and transmits an echo resonated with the signal to the main device, and a second antenna that receives the monitoring frequency signal from the signal generator. In an electromagnetically coupled communication device configured with a corresponding resonant circuit, the resonant circuit of the sensor device has an LCX parallel resonant circuit consisting of a second antenna, a capacitor, and a solid-state resonator, and Echo state changing means for changing the LC resonant frequency of the LCX parallel resonant circuit with respect to the resonant frequency of X due to a state change, and changing the state of the echo with respect to the monitoring frequency signal by varying the Q of the resonant frequency of X. It is designed to additionally have the following.

[0008] The present invention according to claim 2 is the invention according to claim 1, further characterized in that the echo state changing means is
It is designed to change the

The present invention according to claim 3 is the present invention according to claim 1, further characterized in that the echo state changing means is C.
It is designed to change the

[0010] The present invention according to claim 4 is based on claims 1 to 3.
In the present invention according to any one of the above, the echo state changing means shortens the echo duration time by reducing the Q of the resonance frequency of X by bringing the LC resonance frequency closer to the resonance frequency of The detection section is configured to detect a change in the state of the detected section based on the length of the echo duration time.

[0011] In the present invention as set forth in claim 5, in the present invention as set forth in claim 4, the detection section further determines the echo duration time depending on whether or not there is an echo beyond the echo detection timing by the changeover switch. It is designed to distinguish between long and short.

[0012] In the present invention as set forth in claim 6, in the present invention as set forth in claim 4, the detection unit further integrates the level of the echo from the sensor device for a certain period of time, and determines the echo duration time based on the integrated amount. It is designed to distinguish between long and short.

[0013] The present invention according to claim 7 is based on claims 1 to 6.
In the present invention according to any one of the above, further, the first antenna of the main device is installed on a ceiling, the LCX parallel resonant circuit of the sensor device is installed on a window frame, and the echo state changing means of the sensor device is installed on a window frame. The device is installed in a window, and the action of the echo state changing means on the LCX parallel resonant circuit is made variable by the opening/closing operation of the window relative to the window frame, thereby configuring a window intrusion sensing device.

[0014] The present invention according to claim 8 is based on claims 1 to 7.
In the present invention according to any one of the above, the solid-state resonator is a crystal resonator.

[0015]

[Operation] The resonance frequency f1 of X in the LCX parallel resonance circuit is the same as the LC resonance frequency f0 and f in Figs.
0 ′ (f0 < f0 ′ < f1 ),
When the LC resonance frequency is brought closer to the X resonance frequency, the Q of the X resonance frequency becomes smaller as shown in FIGS. 3(A) to 3(B). When the Q of the resonance frequency of X becomes smaller, the echo duration time t at a constant level V0 as an echo state becomes shorter as shown from t0 in FIG. 3(A) to t1 in FIG. 3(B).

According to the present invention, due to the presence of the echo state changing means, the LC is changed due to the state change of the detected part.
Since the echo state is changed by changing the resonant frequency with respect to the resonant frequency of X and changing the Q of the resonant frequency of This means that changes in the state of the detection section can be detected.

[0017]

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is an electric circuit diagram showing an embodiment of the present invention, FIG. 3 is a schematic diagram showing changes in Q and changes in echo level, and FIG. 4 is a schematic diagram showing a window intrusion sensing device.

As shown in FIGS. 1 and 2, the electromagnetic coupling communication device 10 includes a main device 20 and sensor devices 30 (3
0A, 30B, 30C...).

The main device 20 includes a signal generator 21, a detector 22, and a first antenna 23 (inductance L1).
, a changeover switch 24 , a control section 25 , and a display section 26 .

The signal generating section 21 sequentially and cyclically sends out monitoring frequency signals of different frequencies f1, f2, f3, . . . at a predetermined period by switching the oscillation circuit or by performing frequency modulation.

The detection section 22 takes in a signal from the sensor device 30, performs signal amplification, etc., and detects the presence or absence of an echo. At this time, the detection unit 22 detects a change in the state of each monitoring target area from the presence or absence of an echo and its frequency.

The first antenna 23 is, for example, a loop antenna, and transmits the signal generated by the signal generator 21 and receives the echo by electromagnetic coupling.

The changeover switch 24 selectively connects the signal generating section 21 and the detecting section 22 to the first antenna 23.

The control section 25 controls starting and stopping of the signal generating section 21, and also controls the signal generating section 21 every time the signal generating section 21 sends out a frequency signal for monitoring, immediately before the echo from the sensor device 30 attenuates. Switch the changeover switch 24 to the detection section 22 side.

The display section 26 displays the detection results of the detection section 22.
For example, the information is displayed by turning on or off a light emitting element, or by sounding a buzzer.

Sensor device 30 (30A, 30B, 30C
...) is the second antenna 31 (inductance L2)
, a capacitor 32 (capacitance C2), and a crystal resonator 33
(X) and a closed circuit 34.

The second antenna 31 of the sensor device 30 is
It is formed in a part of the closed circuit 34, and the monitoring frequency signal f1 from the signal generator 21 of the main device 20 is generated by electromagnetic coupling.
, f2, f3... and transmits an echo resonating with any one of those frequencies.

In the sensor device 30, the second antenna 31, capacitor 32, and crystal resonator 33 constitute an LCX parallel resonant circuit.

Furthermore, the sensor device 30 changes the LC resonant frequency f0 of the LCX parallel resonant circuit with respect to the resonant frequency f1 of
It additionally includes an echo state changer 40 that changes the echo state for the monitoring frequency signal f1 by changing the Q of the resonant frequency.

At this time, the echo state changer 40 changes the LC
It may be one that changes L of the X parallel resonant circuit,
Alternatively, C may be changed.

Furthermore, the echo state changer 40 is as shown in FIG.
As shown in (A) and (B), the LC resonance frequency f0 is
By bringing the resonant frequency f1 of X closer to the resonant frequency f1 as shown in FIG. 22 makes it possible to detect changes in the state of the monitoring target area based on the length of the echo duration time.

The detection section 22 of the main device 20 adjusts the echo detection timing, which is the switching timing of the changeover switch 24, and determines the echo duration depending on whether or not there is an echo beyond the echo detection timing. Can distinguish between long and short.

The detecting section 22 of the main device 20 can also integrate the level of the echo from the sensor device 30 for a certain period of time, and can identify the length of the echo duration based on the integrated amount.

Next, the operation of the electromagnetically coupled communication device 10 will be explained.

At this time, as shown in FIG. 4, the loop antenna 23 of the main device 20 is provided on the ceiling of one of the plurality of monitoring target areas of the electromagnetically coupled communication device 10, and the sensor device 30A of this monitoring area is connected to the loop antenna 23 of the main device 20. An LCX parallel resonant circuit having a loop antenna 31 is installed on the window frame 51, and a coil constituting the echo state changer 40 of the sensor device 30A is installed on the window frame 51.
The echo state changer 40 for the LCX parallel resonant circuit is installed at
It is assumed that a window intrusion sensing device is configured with variable action.

(A) When the window 52 is closed (see FIG. 4(A)) In this case, the LCX parallel resonant circuit on the window frame 51 side is closed so that the Q of the resonance frequency of X is maximized. The coil and the coil of the echo state changer 40 on the window 52 side are adjusted in advance. Thereby, the echo duration exceeds the echo detection timing determined by the changeover switch 24.

■ The selector switch 24 is set to the signal generating section 21 side (
Contact a) is set, and currents of frequencies f1, f2, f3...fn are cyclically passed from the signal generating section 21 to the first antenna 23.

[0038] Due to the above (■), magnetic flux is generated from the first antenna 23, and the sensor device 3 constituting the window intrusion sensing device is
0A resonates, and a resonant current flows to the second antenna 31.

(2) At a certain echo detection timing synchronized with the end of the transmission in (2) above, the changeover switch 24 is switched to the detection section 22 side (contact b).

(2) Due to the above (2), the magnetic flux from the first antenna 23 disappears, and an echo (alternating magnetic flux) is generated from the second antenna 31.

[0041] The first antenna 23 and the second antenna 31 are electromagnetically coupled through the mutual inductance M, and an induced current flows through the first antenna 23.

[0042] That is, the echo generated in the sensor device 30A in response to the monitoring frequency signal is received by the first antenna 23 by electromagnetic coupling, and this received signal is input to the detection section 22 through the changeover switch 24, where it is transmitted to the sensor device 30A. is amplified.

(2) The detection unit 22 determines the monitoring target area to which this frequency is assigned from the frequency of the input received echo, and displays the closing information of the window 52 in the monitoring target area on the display unit 26.

(B) When the window 52 is opened (FIG. 4(B)
)) In this case, due to mutual induction between the coil of the LCX parallel resonant circuit on the window frame 51 side and the coil of the echo state changer 40 on the window 52 side, the overall value of L changes, and the LC resonance frequency changes. By approaching the resonant frequency of X, the Q of the resonant frequency of X becomes smaller, and the echo duration time becomes shorter. As a result, the echo duration time cannot exceed the echo detection timing determined by the changeover switch 24.

[0045] Therefore, after the same operations as those described in (A) (1) to (3) have passed, the echo generated in the sensor device 30A is detected by the changeover switch 24 at a certain echo detection timing.
The echo is attenuated before being switched to the detecting section 22 side, and the detecting section 22 is unable to detect the presence of the echo. Thereby, the detection unit 22 displays information on the opening of the window 52 in the monitoring target area on the display unit 26.

According to the above embodiment, the following effects (1) and (2) are achieved.

(2) Since the state change of the detected part is identified by the variation in the echo level of the resonance frequency of X in the LCX parallel resonance circuit, the configuration is simple.

(2) Since the echo of the LCX parallel resonant circuit has a large Q, the echo duration time is long, and as a result, the echo detection margin time is long. Furthermore, when using detectors that require the same amount of time to detect echoes, the echo detectable distance can be increased.

[0049]

As described above, according to the present invention, with a simple configuration, it is possible to identify a change in the state of the detected part while increasing the echo detection margin time and the echo detectable distance.

[Brief explanation of the drawing]

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

FIG. 2 is an electrical circuit diagram showing one embodiment of the present invention.

FIG. 3 is a schematic diagram showing changes in Q and changes in echo level.

FIG. 4 is a schematic diagram showing a window intrusion sensing device.

[Explanation of symbols]

10 Electromagnetic coupling communication device 20 Main device 21 Signal generation section 22 Detection section 23 First antenna 24 Selector switch 25 Control section 26 Display section 30 Sensor device 31 Second antenna 32 Capacitor 33 Crystal resonator 40 Echo status changer

Claims (8)

[Claims] Claim 1: Consisting of a main device and a sensor device placed at a specific location in a building separated from the main device, the main device includes a signal generator that generates a specific monitoring frequency signal, and a sensor device that generates a specific monitoring frequency signal, a detection section that detects the state of the echo; a first antenna that transmits a signal generated by the signal generation section to the sensor device by electromagnetic coupling and receives the echo from the sensor device; It has a changeover switch that connects to the first antenna, a control unit that switches the changeover switch to the signal generation unit and the detection unit at regular intervals, and a display unit that displays the detection results of the detection unit. The sensor device includes a second antenna that receives a monitoring frequency signal from the signal generator through electromagnetic coupling and transmits an echo resonated with the signal to the main device, and a monitoring frequency signal from the signal generator. In an electromagnetically coupled communication device configured with a resonant circuit corresponding to a frequency signal, the resonant circuit of the sensor device has an LCX parallel resonant circuit consisting of a second antenna, a capacitor, and a solid resonator, and An echo that changes the LC resonant frequency of the LCX parallel resonant circuit with respect to the resonant frequency of X due to a change in the state of the detection unit, and changes the state of the echo with respect to the monitoring frequency signal by varying the Q of the resonant frequency of X. An electromagnetic coupling communication device characterized by additionally having state changing means. 2. The electromagnetically coupled communication device according to claim 1, wherein the echo state changing means changes L. 3. The electromagnetically coupled communication device according to claim 1, wherein the echo state changing means changes C. 4. The echo state changing means shortens the echo duration time by reducing the Q of the resonance frequency of X by bringing the LC resonance frequency closer to the resonance frequency of The electromagnetic coupling communication device according to any one of claims 1 to 3, wherein a change in the state of the detected section is detected depending on the length of time. 5. The electromagnetically coupled communication device according to claim 4, wherein the detecting section identifies the length of the echo duration based on whether or not there is an echo beyond the echo detection timing by the changeover switch. 6. The electromagnetically coupled communication device according to claim 4, wherein the detection unit integrates the level of the echo from the sensor device for a certain period of time, and identifies the length of the echo duration based on the integrated amount. 7. A first antenna of the main device is installed on a ceiling, an LCX parallel resonant circuit of the sensor device is installed on a window frame, and an echo state changing means of the sensor device is installed on a window, Due to the opening/closing operation of the window relative to the frame, the LC
The electromagnetically coupled communication device according to any one of claims 1 to 6, wherein the action of the echo state changing means on the X parallel resonant circuit is made variable to constitute a window intrusion sensing device. 8. The electromagnetically coupled communication device according to claim 1, wherein the solid-state resonator is a crystal resonator.