JP6635838B2 - Intercom system - Google Patents

Description

  The present invention relates to an intercom system in which a visitor calls a resident and talks, and more particularly to an intercom system having a wireless base unit in addition to a fixed room base unit as a device operated by the resident to answer.

  There is an intercom system provided with a wireless base unit that can be carried and moved in addition to a fixedly installed living room base unit (for example, see Patent Document 1). In a system having such a wireless master unit, microwaves are usually used for communication between the living room master unit and the wireless master unit, and a synchronization signal of, for example, 1.9 GHz is transmitted from the living room master unit to the wireless master unit during operation standby. Are sent at regular intervals.

  On the other hand, there is an intercom system that can obtain safety information of residents. For example, in Patent Literature 2, when a human sensor is connected to the parent device of the living room and the human sensor does not perform the detection operation for a certain period of time, it is determined that the parent device of the room is abnormal, and if a confirmation operation is performed from the entrance child device, the abnormality is detected. The occurrence is notified to the entrance slave unit.

JP 2013-90206 A JP 2015-32960 A

In the conventional intercom system capable of confirming the safety, it was necessary to connect a human sensor to the parent device in the room in order to detect the presence of a resident. In addition, the connected human sensor is widely used due to its low cost of the pyroelectric infrared method that detects by heat change.However, it is easily affected by the surrounding environment, so it can be used as a sensor that detects a person moving indoors. Errors were easy to occur. Therefore, a method of detecting a person using microwaves to improve the accuracy is conceivable, but the cost is high.
In this regard, in a system equipped with a wireless master device, microwaves are used to communicate with the wireless master device, and if this reflected wave can be used to detect an approaching person, the resident can use it without using a human sensor. Can be watched over.

  Therefore, the present invention provides an intercom system that uses the function of communicating with the wireless master unit to detect the presence of a person and enable a resident to watch without connecting a separate human sensor. The purpose is.

In order to solve the above-mentioned problems, the invention of claim 1 provides an entrance slave unit for a visitor to call a resident and make a call, and a living room master unit for a resident to answer a call from the entrance slave unit. An intercom system having a wireless base unit for wirelessly communicating with a room base unit and responding to a call from an entrance slave unit, the room base unit includes two antennas for wirelessly communicating with the wireless base unit and two antennas An antenna switching device that switches between a wireless base unit and a wireless communication unit that periodically transmits a synchronization signal using a microwave to the wireless base unit during standby and performs communication, and selects an antenna to be used by spatial diversity control, To remove the carrier frequency component from the reflected wave by calculating the product of the traveling wave attenuated by the attenuation means and the reflected wave coming from the other antenna not selected A mixer circuit, to a moving object determination unit for determining the presence of a moving object from the phase difference information mixer circuit outputs, and characterized by including the.
According to this configuration, since the living room base unit uses the function of wirelessly communicating with the wireless base unit to detect the moving body around the room main unit, that is, the resident, the resident or the like can be installed without installing a separate human sensor. Approach can be detected, and residents can be watched over. Also, judgment is made based on the reflected wave of the microwave, so that false detection can be reduced compared to the pyroelectric infrared method, and a directional coupler should be used to use the reflected wave that enters the unselected antenna. A reflected wave can be obtained without any space, and a human sensor can be constructed in a small space.

According to a second aspect of the present invention, in the configuration according to the first aspect, a sample-and-hold circuit for holding an output signal of the mixer circuit for a predetermined time is provided.
According to this configuration, even if the synchronization signal is a burst-like intermittent signal, the output of the mixer circuit is held, so that the influence of the burst can be eliminated and the presence of a person can be detected well from the reflected wave.

According to a third aspect of the present invention, in the configuration according to the first or second aspect, while the entrance slave unit has a camera for imaging the visitor, the living room master unit displays a captured image of the camera, and a captured image. Having a video storage unit and a base unit control unit for storing and controlling the captured video of the camera,
When the time during which the moving object determination unit does not detect the moving object exceeds a predetermined time, the master unit control unit performs an answering machine mode operation for saving a captured image of a camera activated in response to a call operation of the entrance slave unit. It is characterized by.
According to this configuration, if the moving object is not detected for a predetermined time, the mode shifts to the answering machine mode, and if there is a visitor, the image captured by the camera is stored. Therefore, even if the user forgets to set the answering machine mode when going out, the user automatically shifts to the answering machine mode and records the visitor.

According to a fourth aspect of the present invention, in the configuration according to the third aspect, the living room parent device displays a preset start screen on the monitor at the time of start-up, and the parent device control unit determines that the moving object determination unit detects the moving object. And displaying a start screen on the monitor.
According to this configuration, the monitor performs a display operation when the resident approaches the parent device in the room, so that predetermined information can be displayed without performing a separate display operation, which is convenient.

According to a fifth aspect of the present invention, in the configuration according to the third or fourth aspect, the living room base unit has a communication unit that communicates with an external communication device via a public communication network, and the base unit control unit includes a mobile unit. If the determination unit does not detect the moving object for a certain period of time exceeding a predetermined time, the determination unit transmits an abnormality occurrence signal to the communication device.
According to this configuration, when the resident cannot be confirmed for a long time, the resident can be notified to the outside, an abnormality occurring to the resident can be grasped without visiting, and the resident can be watched.

  ADVANTAGE OF THE INVENTION According to this invention, since the living room parent machine uses the function which carries out wireless communication with a wireless parent machine, the moving body around a room parent machine, ie, a resident, is detected. Approach can be detected, and residents can be watched over. Also, judgment is made based on the reflected wave of the microwave, so that false detection can be reduced compared to the pyroelectric infrared method, and a directional coupler should be used to use the reflected wave that enters the unselected antenna. A reflected wave can be obtained without any space, and a human sensor can be constructed in a small space.

It is a lineblock diagram showing an example of an intercom system concerning the present invention. It is a circuit block diagram of a living room parent machine. It is a circuit block diagram of the wireless communication part of a living room parent machine. It is an explanatory view of a signal, (a) shows a traveling wave signal which is a synchronization signal, (b) shows a reflection signal, and (c) shows an output of a sample and hold circuit. FIG. 9 is a circuit block diagram illustrating another configuration of the wireless communication unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing an example of an intercom system according to the present invention. Reference numeral 1 denotes an entrance cordless handset for a visitor to call a resident and talk, and 2 denotes a resident responding to a call from the entrance cordless handset. 3 is a wireless base unit for wirelessly communicating with the room base unit 2 and responding to a call from the entrance slave unit 1, 6 is a server (communication device) installed outside, N is the Internet, etc. Is a public communication network. The entrance child device 1 and the living room master device 2 are connected by a transmission line L, and the wireless master device 3 performs wireless communication with the living room master device 2.

  The entrance device 1 has a call button 11, a camera 12, a microphone 13 and a speaker 14. When the call button 11 is pressed down, a call signal is transmitted to the living room master device 2, and the camera 12 is activated to take an image thereof. The video is transmitted to the parent device 2.

  The living room parent device 2 includes a monitor 21 for displaying an image captured by the camera 12, a call button 22 for responding to a call, an operation unit 23 for performing various operations, a microphone 24a and a speaker 24b for talking. I have. Then, when a calling signal is transmitted from the entrance cordless handset 1, a ringing tone is sounded, and an image captured by the camera 12 is displayed on the monitor 21. When the call button 22 is pressed in response to the call, a communication path is formed, and a call can be made between the visitor and the resident.

  In addition, the wireless master device 3 has a monitor 31 for displaying an image captured by the camera 12, a call button 32 for responding to a call, and a communication unit (not shown). Then, when a call signal is transmitted from the entrance child device 1 to the room master device 2, a call signal is transmitted from the room master device 2 to the wireless master device 3, and a ringing tone sounds together with the room master device 2. The video signal transmitted to the parent device 2 is transmitted from the parent device 2 to the wireless device 3, and the captured image of the camera 12 is displayed on the monitor 31. Then, when the call button 32 is pressed before the living room master unit 2, a communication path is formed between the entrance slave unit 1 and the wireless master unit 3 via the living room master unit 2, and a call is possible.

  FIG. 2 shows a circuit block diagram of the parent room 2. As shown in FIG. 2, in addition to the monitor 21, the call button 22, the operation unit 23, the microphone 24 a, and the speaker 24 b, the living room base unit 2 generates an audio unit 24 for controlling call voice and an image displayed by the monitor 21. The image processing unit 25, a recording memory 26 for recording an image captured by the camera 12, a wireless communication unit 27 for communicating with the wireless parent device 3, an external communication IF 28 for communicating with an external server 6, and a wireless parent device for controlling the living room parent device 2 A main unit CPU 29 for controlling communication with the main unit 3 and a main unit IF 30 for communicating with the entrance slave unit 1 are provided.

FIG. 3 is a circuit block diagram of the wireless communication unit 27 of the parent device 2, and the configuration and operation of the wireless communication unit 27 will be specifically described below.
In FIG. 3, reference numeral 41 denotes a wireless communication unit that communicates with the wireless base unit 3; 42, two antennas (first antenna 42a and second antenna 42b) for transmitting and receiving radio waves to and from the wireless base unit 3; An antenna switch for switching, 44 is a resistance element as an attenuating means for attenuating a traveling wave, 45 is an RF amplifier for amplifying a reflected wave, 46 is a traveling wave attenuated by the attenuating means 44 and a reflected wave output from the RF amplifier 45. A mixer circuit for mixing and removing a carrier frequency component from a reflected wave, 47 is an IF amplifier for amplifying an output of the mixer circuit 45, 48 is a sample-and-hold circuit, and 49 is for determining the presence of a moving body P such as a resident. This is the amplitude determination unit that performs the determination.

  The antenna switch 43 selects the antenna 42 that receives the reflected wave of the synchronization signal in order to detect the moving object P, in addition to the first switch 43 a that selects the antenna 42 that communicates with the wireless master device 3. A second switch 43b is provided, and both are configured to perform an inverting operation.

The wireless communication unit 41 generates a synchronization signal in the 1.9 GHz band during operation standby and constantly transmits the synchronization signal to the wireless parent device 3 via the antenna 42 at regular intervals (for example, at intervals of 10 ms).
Diversity control in which the first antenna 42a and the second antenna 42b are switched and controlled by the antenna switch 43 under the control of the wireless communication unit 41 is performed. Specifically, the antenna 42 communicating with the wireless master device 3 is automatically switched between the first antenna 42a and the second antenna 42b by the switching of the first switch 43a. On the other hand, the second switch 43b that performs the reversing operation is simultaneously switched to the antenna 42 that is not used for communication and is used for detecting the moving object P.

Specifically, the reflected wave of the synchronization signal is received by the antenna 42 not used for communication, and the received reflected wave is amplified by the RF amplifier 45 and then multiplied by the traveling wave in the mixer circuit 46. The operation of the mixer circuit 46 can be represented by the following mathematical expression.
First, assuming that the distance between the antennas x, the traveling wave frequency f, the phase variation φ (t) due to the reflector, the traveling wave amplitude Atx, and the reflected wave amplitude Arx, the traveling wave (Pf) and the reflected wave (Pr) are as follows. Is represented by

尚、ｘは固定値であり、時間変動には寄与しない。
この式から、ミキサ回路４６の出力ＩＦ（ｔ）は次式で表される。

Note that x is a fixed value and does not contribute to time variation.
From this equation, the output IF (t) of the mixer circuit 46 is expressed by the following equation.

From this equation, it is not necessary to handle the frequency of 1.9 GHz, which is the carrier frequency (traveling wave frequency f), and the determination can be made based on the magnitude and phase information of the signal, and the determination becomes easy.
Then, after the output of the mixer circuit 46 is amplified by the IF amplifier 47, the waveform is held by the sample and hold circuit 48, and the presence or absence of the moving object P is determined by the amplitude determination unit 49.

4A and 4B are explanatory diagrams of the signals of the main part. FIG. 4A shows the traveling wave signal Pf, FIG. 4B shows the reflected wave signal Pr, and FIG. 4C shows the output signal of the sample and hold circuit 48. As shown in FIG. 4A, the synchronization signal is a 1.9 GHz band signal with a period T1 of 10 ms and a time width T2 of 40 μs. As described above, although the synchronization signal is transmitted at a constant period, the amplitude determination unit 49 can perform highly accurate determination after that since the reflected wave signal is held by the sample and hold circuit 48. The sample hold circuit 48 holds the signal with a time width equal to the period T1 of the synchronization signal.
Then, since the output of the mixer circuit 46 changes due to the presence of the moving object P, the output of the sample hold circuit 48 changes as shown in FIG.

As described above, since the living room master device 2 uses the function of wirelessly communicating with the wireless master device 3 to detect the moving object P around the living room master device 2, the approach of a resident or the like without installing a separate human sensor is required. Can be detected, and the judgment is made based on the reflected wave of the microwave.
Also, even if the synchronization signal is a burst-like intermittent signal, the output of the mixer circuit 46 is held by the sample-and-hold circuit 48, so that the influence of the burst can be eliminated and the presence of a person can be detected well from the reflected wave.
In addition, since a reflected wave coming into the unselected antenna 42 is used, a reflected wave can be obtained without using a directional coupler, and a human sensor can be configured in a small space.
Here, when an example in which a directional coupler is used is shown, since a quarter wavelength length is required, when the carrier frequency is 1.9 GHz, the length is about 4 cm. A space of at least this long is required for that.

By utilizing the function of detecting the presence of the occupant from the reflected wave of the synchronization signal, the occupant watching over the intercom system and other operations are performed as follows.
When the time during which the presence of the resident is not detected continues for, for example, 10 hours (first set time), the base unit CPU 29 determines that the resident has gone out and controls the shift to the answering machine mode. When the mode shifts to the answering machine mode, the image is recorded in the recording memory 26 when the camera 12 starts imaging in response to the pressing of the call button 11 of the entrance cordless handset 1.

If a resident cannot be detected even after elapse of, for example, 24 hours (second set time) longer than the first set time, the base unit CPU 29 determines that an abnormality has occurred in the resident, and An abnormality occurrence signal is transmitted to the server 6 via N.
The server 6 is installed in a security company or the like. Upon receiving the signal, the server 6 reads out the relevant address, resident name, and the like from the pre-registered watching address data, displays them on a display (not shown), and sounds an alarm sound. To notify the occurrence of abnormality by display and sound.

As described above, if the moving object P is not detected for a predetermined time, the mode is shifted to the answering machine mode, and if there is a visitor, the image captured by the camera 12 is stored. Therefore, even if the user forgets to set the answering machine mode when going out, the user automatically shifts to the answering machine mode and records the visitor.
In addition, when the resident cannot be confirmed for a long time, the resident is notified to the outside, so that the abnormality that has occurred in the resident can be grasped without visiting, and the resident can also watch.

Further, upon detecting a resident, base unit CPU 29 activates monitor 21 from the standby state, and displays a predetermined start screen (not shown). Note that the start screen is, for example, a selection screen for performing various operations, or an image of the entrance taken by the camera 12.
As described above, since the monitor 21 performs the display operation when the resident approaches the living room master unit 2, predetermined information can be displayed without performing a separate display operation, and the convenience is good.

  FIG. 5 shows another embodiment of the intercom system, showing a modified example of the configuration of the wireless communication unit 27 of the parent device 2, in which an integrating circuit 50 is provided instead of the sample and hold circuit 48. Thus, the moving object P can be determined simply by integrating the output signal of the mixer circuit 46.

  In the above embodiment, the occurrence of the abnormality of the resident is notified to the external server 6, but may be notified to the mobile terminal carried by the welfare officer or the family.

  1. Entrance cordless handset, 2. Living room master unit, 3. Wireless master unit, 6. Server (communication device) 12, Camera, 21 Monitor, 26 Recording memory, 27 Wireless communication Unit, 29: Base unit CPU (base unit control unit), 31: Monitor, 42: Antenna, 42a: First antenna, 42b: Second antenna, 43: Antenna switcher, 44: Resistance Element (attenuating means), 46..mixer circuit, 47..IF amplifier, 48..sample and hold circuit, 49..amplitude determination unit (moving object determination unit).

Claims (5)

An entrance slave unit for a visitor to call a resident to make a call, a resident base unit for a resident to respond to a call from the entrance slave unit, and the entrance slave unit wirelessly communicating with the living room master unit. Intercom system having a wireless base unit for answering calls from
The living room base unit has two antennas for wirelessly communicating with the wireless base unit,
An antenna switch for switching between the two antennas,
A wireless communication unit that transmits a synchronization signal using a microwave periodically to the wireless master device during standby and performs communication, and selects an antenna to be used by space diversity control,
A mixer circuit for determining the product of the traveling wave attenuated by the attenuating means and the reflected wave coming from the other antenna that is not selected, and removing a carrier frequency component from the reflected wave,
A mobile object determining unit that determines the presence of a mobile object based on the phase difference information output by the mixer circuit.   2. The intercom system according to claim 1, further comprising a sample-and-hold circuit for holding an output signal of the mixer circuit for a predetermined time. The entrance cordless handset has a camera for imaging the visitor, while the living room master unit displays a video image of the camera, a video storage unit for storing the video image, and a video image of the camera. Having a base unit control unit for performing storage control,
When the time during which the moving object determination unit does not detect the moving object exceeds a predetermined time, the master unit control unit stores an image captured by the camera activated in response to the call operation of the entrance cordless handset, and an answering machine mode operation. 3. The intercom system according to claim 1, wherein: The living room master unit displays a preset start screen on the monitor at startup,
4. The intercom system according to claim 3, wherein the master unit control unit displays the start screen on the monitor when the moving body determination unit detects a moving body. 5. The living room master unit has a communication unit that communicates with an external communication device via a public communication network,
The said base unit control part transmits an abnormality occurrence signal to the said communication apparatus, unless the said moving body determination part detects a moving body over the fixed time exceeding the said predetermined time, The said 3rd or 4th characterized by the above-mentioned. The intercom system described.

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