JP2010011218A - Intercom system and monitor camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intercom system that enables two-way communication only by using a pair of transmission lines, even if a physical layer of a local area network (LAN) is used. <P>SOLUTION: An intercom slave unit 1 and an intercom master unit 2 includes transmission frame disassembly circuits 15, 25 for encapsulating and transmitting/receiving transmission data with preamble and idle to be used for a MAC frame of a LAN and LAN physical layer construction parts 16, 26 for converting the transmission data into physical layer data. Both the units are connected by a pair of transmission lines L1 each including a transmitting terminal and a receiving terminal among transmission lines constituting the LAN physical layer. Furthermore, broadband analog switches 17, 27 are provided for converting high/low impedance of the transmitting terminal and the transmission frame disassembly circuit 15, 25 switch the high/low impedance of the transmitting terminal in prescribed timing, thereby alternately implementing transmission/reception of encapsulated transmission data. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an interphone system and a surveillance camera system, and more particularly to a communication form used for communication between devices of these systems.

The conventional intercom system used by visitors to call residents is equipped with an interphone cordless handset at the entrance and an interphone master phone inside the dwelling unit, with a two-wire dedicated transmission line between them. Connected. In addition, a conventional surveillance camera system for monitoring a suspicious person appearing around a dwelling unit has a sensor camera that takes an image of a person approaching the dwelling unit and a monitor device in the dwelling unit. The two are connected by a two-wire dedicated transmission line.
However, because of the ease of system expansion, there is a communication mode in which communication between devices is performed using a local area network (hereinafter referred to as “LAN”) instead of the communication mode using the dedicated transmission line described above. is there. For example, in Patent Document 1, communication between an interphone slave unit and an interphone master unit, a monitoring camera device, and a monitor are performed by performing bidirectional communication using four transmission lines in the LAN physical layer. Communication with the device was made possible.
JP 2004-235858 A

  However, if the conventional system using the two-wire transmission line is changed to a form using the LAN, four transmission lines are required, so at least two new transmission lines are allocated. It wouldn't have been possible without it. For this reason, it is troublesome to change the existing intercom equipment or the like to a configuration using a LAN, and a system that can effectively use the existing wiring equipment has been desired.

  Therefore, the present invention has been made in view of such problems, and an interphone system and a surveillance camera system that can perform bidirectional communication by using only a pair of transmission lines even when a physical layer of a LAN is used. The purpose is to provide.

In order to solve the above-mentioned problem, the invention of claim 1 is directed to a physical layer of a local area network comprising an interphone slave unit having a function of calling and calling a resident and an interphone master unit having a function of responding to a call. The interphone slave unit and the interphone master unit are connected to a pair of transmission lines each having a transmission terminal and a reception terminal among transmission lines constituting the physical layer. And an encapsulating means for encapsulating transmission data such as call data in a preamble and an idle used in a MAC frame of a local area network, and an impedance switching means for switching a transmission line impedance between high and low. And an impedance control unit for switching and controlling the impedance switching means. Impedance control unit, which comprises carrying out the half-duplex communication with the intercom slave unit and intercom master unit as enabling communication transmission data encapsulated by switching the impedance at a predetermined timing.
According to this configuration, two-way communication can be performed using a pair of transmission lines constituting the physical layer of the local area network, and a call can be made between a visitor and a resident. Therefore, the communication between the interphone slave unit and the interphone master unit is configured to use the local area network without arranging a new transmission line in addition to the two-wire transmission line used in the existing system. Can change.

The invention of claim 2 is a surveillance camera system in which a surveillance camera device for imaging a suspicious person and the like and a monitor device for displaying a captured image of the surveillance camera device are connected using a physical layer of a local area network. The monitoring camera device and the monitoring device are each connected to a pair of transmission lines each having a transmission terminal and a reception terminal among transmission lines constituting the physical layer, and a MAC frame of the local area network is connected to the monitoring camera device. In addition to providing an encapsulating means for encapsulating video data to be transmitted with a preamble and an idle used in the zoom, a zoom transmitted in the preamble and idle used in the MAC frame of the local area network in the monitor device, Encapsulation means for encapsulating camera control data such as pan / tilt is provided. , An impedance switching means for switching the impedance of the transmission line, and an impedance control section for switching and controlling the impedance switching means, respectively, and the impedance control section switches the impedance at a predetermined timing and is encapsulated video Data and control data can be transmitted, and half-duplex communication is performed between the monitoring camera device and the monitoring device.
According to this configuration, bidirectional communication can be performed using a pair of transmission lines constituting the physical layer of the local area network, and a suspicious person can be monitored. Therefore, the communication between the monitoring camera and the monitoring device can be changed to a configuration using a local area network without providing a new transmission line in addition to the two-wire transmission line used in the existing system. .

According to a third aspect of the present invention, in the first aspect of the present invention, the impedance switching means is a broadband analog switch.
According to this configuration, high / low impedance of the transmission line can be switched reliably, and good communication can be realized.

The invention according to claim 4 is the invention according to claim 2, wherein the impedance switching means is a broadband analog switch.
According to this configuration, high / low impedance of the transmission line can be switched reliably, and good communication can be realized.

  According to the present invention, interphone calls and suspicious person monitoring can be performed using a pair of transmission lines constituting the physical layer of the local area network. Therefore, the two-wire transmission line used in the existing system can be utilized, and the existing intercom equipment and surveillance camera equipment can be changed to a configuration using the local area network without providing a new transmission line.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of an interphone system according to the present invention, which is composed of an interphone slave unit 1 for a visitor to call a resident and an interphone master unit 2 for responding to a call from the interphone slave unit 1. Both are connected by a pair of transmission lines L1 constituting the LAN physical layer. The configuration of each device is as follows.

  As shown in FIG. 1, the intercom handset 1 has a camera 11 that images a visitor and outputs a digital image signal, a microphone 12 that collects sound, a speaker 13 that outputs sound, and converts the sound signal into a digital signal. Alternatively, a slave unit codec 14 that performs the reverse, a slave unit transmission frame assembly / separation circuit 15 that assembles and separates transmission frames to send and receive data, and a transmission terminal and a reception terminal in the physical layer of the LAN are connected. LAN physical layer construction unit 16 for communication, and a broadband analog switch that performs switching operation so that the transmission terminal of the LAN physical layer construction unit 16 can be seen in either the output state (low impedance state) or the high impedance state when viewed from the transmission line L1. 17, a pulse transformer 18 and the like for insulating between the transmission line L1 and the circuit of the intercom slave unit 1 are provided. The slave unit transmission frame assembling / separating circuit 15 is also an impedance control unit for controlling on / off of the broadband analog switch 17.

  The interphone master unit 2 also converts a display 21 for displaying a digital video signal, a microphone 22 for collecting voice, a speaker 23 for outputting voice, a calling signal, and the like, and converts the voice signal into a digital signal or vice versa. Base unit codec 24, base unit transmission frame assembly / separation circuit 25 that assembles and separates transmission frames to send and receive data, LAN for communication by connecting transmission terminals and reception terminals in the physical layer of LAN Broadband analog switch 27 for switching operation so that the transmission terminal of the physical layer construction unit 26 and the LAN physical layer construction unit 26 can be seen in either the output state (low impedance state) or the high impedance state when viewed from the transmission line L1, and the transmission line L1 And a pulse transformer 28 and the like for insulating the circuit of the intercom base unit 2 from each other. The base unit transmission frame assembly / separation circuit 25 is also an impedance control unit for controlling on / off of the broadband analog switch 27.

  Next, the operation of the intercom system configured as described above will be described. FIG. 2 is a diagram showing a configuration and a transmission state of a transmission frame transmitted / received via the transmission line L1, and (A) is a downlink transmission frame transmitted from the interphone master unit 2 to the interphone slave unit 1, (B). Indicates an upstream transmission frame transmitted from the interphone slave unit 1 to the interphone master unit 2. FIG. 3 is a timing chart showing transmission timings of the downlink transmission frame (A) and the uplink transmission frame (B).

  As shown in FIG. 2, the transmission frame is configured by encapsulating transmission data (d1) with a preamble (d2) and an idle (d3) used in a LAN MAC frame. Then, as shown in FIG. 3, a downlink transmission frame is transmitted from the interphone master unit 2 to the interphone slave unit 1 at a fixed period T, and the interphone slave unit 1 receives the downlink transmission frame and transmits the uplink transmission frame. To do. Bidirectional communication is performed by performing half-duplex communication in this way.

  Specifically, when the intercom base unit 2 transmits a downlink transmission frame, the base unit transmission frame assembly / separation circuit 25 turns on the wideband analog switch 27 managed by itself to set the transmission terminal of the LAN physical layer construction unit 26. Set to low impedance state. At the same time, the slave unit transmission frame assembly / separation circuit 15 turns off the broadband analog switch 17 so that the transmission terminal of the LAN physical layer construction unit 16 becomes high impedance when viewed from the transmission line L1 and is terminated with the characteristic impedance. To do.

  In this state, the base unit transmission frame assembling / separating circuit 25 generates a downlink transmission frame that encapsulates transmission data composed of call data using a preamble and an idle used in a LAN MAC frame as described above, and performs LAN physical The data is output to the layer construction unit 26. The LAN physical layer construction unit 27 converts this downlink transmission frame into physical layer data that can be transmitted by LAN, and sends it to the transmission line L1. The base unit transmission frame assembling / separating circuit 25 turns off the broadband analog switch 27 after transmitting the downstream transmission frame to set the transmission terminal of the LAN physical layer construction unit 26 to a high impedance state.

  On the other hand, when the interphone slave unit 1 receives the downlink transmission frame from the interphone master unit 2, the interphone slave unit 1 transmits the uplink transmission frame. That is, as described above, the slave unit transmission frame assembly / separation circuit 15 encapsulates transmission data composed of call data and video data in the preamble and idle used in the LAN MAC frame, and generates an upstream transmission frame. The upstream transmission frame is converted into physical layer data by the LAN physical layer construction unit 16 and sent to the transmission line L1. The slave unit transmission frame assembly / separation circuit 15 turns on the broadband analog switch 17 to set the transmission terminal of the slave unit LAN physical layer construction unit 16 to a low impedance state when outputting the upstream transmission frame.

A specific call / response operation is performed as follows. When a call button (not shown) of the intercom handset 1 is operated, call data including a digital signal is generated. This call data is encapsulated in the slave unit transmission frame assembly / separation circuit 15 to form an upstream transmission frame. Then, it is converted into physical layer data by the slave LAN physical layer construction unit 16 and transmitted to the interphone master unit 2 via the transmission line L1.
Note that the intercom handset 1 receives the call operation, the camera 11 is activated, and the captured image data is also transmitted. Like the call data, the imaging data is encapsulated to form an upstream transmission frame and transmitted to the intercom base unit 2.

  The interphone master unit 2 that has received the call data and the video data is subjected to data conversion by the LAN physical layer construction unit 26, and then the encapsulated data is separated by the master unit transmission frame assembly / separation circuit 25. The retrieved call data is converted into an analog signal by the base unit codec 24 and output from the speaker 23 as a ringing tone. On the other hand, the video data separated by the base unit transmission frame assembly / separation circuit 25 is sent to the display 21 and displayed.

  Thereafter, when the resident responds to this call, the sound collected by the microphone 22 is converted into digital data (call data) by the base unit codec 24 and then encapsulated by the base unit transmission frame assembly / separation circuit 25. Thus, a downlink transmission frame is formed, converted into physical layer data by the LAN physical layer construction unit 26, and sent to the interphone slave unit 1 via the transmission line L1.

In the interphone slave unit 1, when this downlink transmission frame is received, the data is converted by the LAN physical layer construction unit 16, and then the call data is separated by the slave unit transmission frame assembling / separating circuit 15, and converted into an audio signal by the slave unit codec 14. Then, the voice of the resident is output from the speaker 13.
The voice of the visitor collected by the microphone 12 is converted into digital data (call data) by the handset codec 14 and then converted into an upstream transmission frame and transmitted to the interphone base unit 2 like the call data. A visitor voice is reported from the speaker 23 of the intercom base unit 2. The transmission of the downstream transmission frame and the transmission of the upstream transmission frame are alternately performed at the timing of the above-described period T under the control of the parent transmission frame assembly / separation circuit 25.

In this way, two-way communication can be performed using a pair of transmission lines constituting the physical layer of the local area network, and a call can be made between a visitor and a resident. Therefore, a configuration using a local area network for communication between the interphone slave unit and the interphone master unit without arranging a new transmission line in addition to the two-wire transmission line used in the existing system Can be changed.
In addition, by switching the impedance with a broadband analog switch, the high / low impedance of the transmission line can be switched reliably, and good communication can be realized.

  FIG. 4 is a block diagram of the surveillance camera system according to the present invention, which is composed of the surveillance camera device 3 and the monitor device 4 for displaying the captured video of the surveillance camera device 3, both of which form a pair constituting the LAN physical layer. Are connected by a transmission line L2. The configuration of each device is as follows.

  As shown in FIG. 4, the surveillance camera device 3 includes a camera 31 that images a visitor and outputs a digital image signal, and a slave unit transmission frame assembly / separation circuit 35 that assembles and separates a transmission frame to send and receive data. The LAN physical layer constructing unit 36 for connecting to and communicating with the transmission terminal and the receiving terminal in the LAN physical layer, and the transmission terminal of the slave LAN physical layer constructing unit 36 are in the output state (low impedance state) as viewed from the transmission line L2. ) Or a wideband analog switch 37 that performs switching operation so that it can be seen in either a high impedance state, a pulse transformer 38 for insulating between the transmission line L2 and the circuit of the monitoring camera device 3 or the like.

  The camera 31 includes a human sensor and is configured to automatically start imaging when a person approaches, and has a pan / tilt control function and a zoom function, and can be controlled from the monitor device 4. Yes. The slave unit transmission frame assembly / separation circuit 35 is also an impedance control unit that controls on / off of the broadband analog switch 37.

  The monitor device 4 includes a display 41 for displaying a digital video signal, an operation unit 44 for performing operations such as pan / tilt of the camera of the monitoring camera device 3, and an assembly of a transmission frame for transmitting and receiving data. The base unit transmission frame assembly / separation circuit 45 that performs the separation, the LAN physical layer construction unit 46 for communication using the physical layer of the LAN, and the transmission terminal of the LAN physical layer construction unit 46 output state (low) as viewed from the transmission line L2. Impedance analog state) or a high-bandwidth analog switch 47 that performs switching operation so that it looks like a high impedance state, a pulse transformer 48 for insulating the transmission line L2 and the circuit of the monitor device 4 and the like. The parent-child transmission frame assembly / separation circuit 45 is also an impedance control unit that controls on / off of the broadband analog switch 47.

Next, the operation of the surveillance camera system configured as described above will be described. FIG. 5 is a diagram illustrating a configuration and a transmission state of a transmission frame transmitted / received via the transmission line L2. (C) is a downlink transmission frame transmitted from the monitor device 4 to the monitoring camera device 3, and (D) is a diagram. An upstream transmission frame transmitted from the monitoring camera device 3 to the monitoring device 4 is shown. FIG. 6 is a timing chart showing transmission timings of the downlink transmission frame and the uplink transmission frame.
As shown in FIG. 5, the transmission frame is configured by encapsulating transmission data (e1) with a preamble (e2) and an idle (e3) used in a LAN MAC frame. Then, as shown in FIG. 6, the downlink transmission frame is transmitted from the monitor device 4 to the monitoring camera device 3 at a constant cycle T, and the monitoring camera device 3 receives the downlink transmission frame and transmits the uplink transmission frame. . Bidirectional communication is performed by performing half-duplex communication in this way.

Specifically, when the monitor device 4 transmits a downlink transmission frame, the base unit transmission frame assembly / separation circuit 45 turns on the wideband analog switch 47 managed by itself to lower the transmission terminal of the LAN physical layer construction unit 46. Set to impedance state. At the same time, the slave unit transmission frame assembly / separation circuit 35 turns off the wideband analog switch 37 so that the transmission terminal of the LAN physical layer construction unit 36 becomes high impedance when viewed from the transmission line L2 and is terminated with the characteristic impedance. Manipulate.
In this state, the base unit transmission frame assembling / separating circuit 45 generates a downlink transmission frame that encapsulates transmission data composed of call data in the preamble and idle used in the LAN MAC frame as described above, and generates the LAN physical Output to the layer construction unit 46. The LAN physical layer construction unit 47 converts this downstream transmission frame into physical layer data that can be transmitted by LAN, and sends it to the transmission line L2. The base unit transmission frame assembling / separating circuit 45 turns off the wideband analog switch 47 after transmitting the downstream transmission frame to set the transmission terminal of the base unit LAN physical layer construction unit 46 to a high impedance state.

  On the other hand, when the monitoring camera device 3 receives the downlink transmission frame from the monitor device 4, the monitoring camera device 3 transmits the uplink transmission frame. That is, as described above, the slave unit transmission frame assembly / separation circuit 35 encapsulates the call data and video data with the preamble and idle used in the LAN MAC frame, and generates an upstream transmission frame. The upstream transmission frame is converted into physical layer data by the LAN physical layer construction unit 36 and sent to the transmission line L2. The slave unit transmission frame assembly / separation circuit 35 turns on the broadband analog switch 37 to set the transmission terminal of the LAN physical layer construction unit 36 to a low impedance state when outputting the upstream transmission frame.

  The specific imaging operation and camera control of the camera 31 are performed as follows. When a human sensor (not shown) of the monitoring camera device 3 senses and the camera 31 starts imaging, the slave unit transmission frame assembly / separation circuit 35 encapsulates the imaging data to form an upstream transmission frame, and constructs the LAN physical layer. The data is converted into physical layer data by the unit 36 and transmitted to the monitor device 4 via the transmission line L2.

The monitor device 4 that has received the encapsulated video data is subjected to data conversion by the LAN physical layer construction unit 46, and then the video data is separated by the parent transmission frame assembly / separation circuit 45. The extracted video data is sent to the display 41 and displayed.
Thereafter, when a resident or the like who views the display image operates the operation unit 44 to perform a pan / tilt operation or the like, a control signal composed of a digital signal is output to the base unit transmission frame assembly / separation circuit 45. The base unit transmission frame assembly / separation circuit 45 encapsulates this control signal (control data) to form a downlink transmission frame, which is converted into physical layer data by the LAN physical layer construction unit 46 and is monitored via the transmission line L2. It is sent to the device 3.

  In the monitoring camera device 3, when the downlink transmission frame is received, the data is converted by the LAN physical layer construction unit 36, and then the control signal is separated by the slave unit transmission frame assembly / separation circuit 35 and sent to the camera 31. Pan / tilt operation is performed. The transmission of the downstream transmission frame and the transmission of the upstream transmission frame are alternately performed at the timing of the above-described cycle T under the control of the parent transmission frame assembly / separation circuit 45.

In this way, bidirectional communication can be performed using a pair of transmission lines constituting the physical layer of the local area network, and suspicious persons can be monitored. Therefore, in addition to the 2-wire transmission line used in the existing system, the communication between the surveillance camera and the monitoring device is changed to a configuration that uses a local area network without providing a new transmission line. it can.
In addition, by switching the impedance with a broadband analog switch, the high / low impedance of the transmission line can be switched reliably, and good communication can be realized.

The surveillance camera system does not have a call function, but may have a call function like the interphone system so that a call can be made with a person imaged by the camera 31.
In the above embodiment, the impedance switching means is the wideband analog switches 17 and 37 in both of the above embodiments, but the LAN physical layer constructing units 16 and 36 may incorporate an impedance switching function.

It is a block diagram which shows an example of the intercom system which concerns on this invention. It is a figure which shows the structure and transmission state of the transmission frame transmitted / received via the transmission line of FIG. FIG. 3 is a timing diagram illustrating transmission timings of a downlink transmission frame and an uplink transmission frame in FIG. 2. It is a block diagram which shows an example of the surveillance camera system which concerns on this invention. FIG. 5 is a diagram illustrating a configuration and a transmission state of a transmission frame transmitted / received via the transmission line in FIG. 4. FIG. 5 is a timing diagram illustrating transmission timings of the downlink transmission frame and the uplink transmission frame of FIG. 4.

Explanation of symbols

  1 .. Interphone slave unit, 2 .... Interphone master unit, 3 .... Surveillance camera, 4 .... Monitor device, 15 .... Slave unit transmission frame assembly separation circuit (encapsulation means, impedance control unit), 16 .... LAN Physical layer constructing unit, 17 ... Broadband analog switch (impedance switching means), 25 ... Master unit transmission frame assembly / separation circuit (encapsulation means, impedance control unit), 26 ... LAN physical layer constructing unit, 27 ... Broadband Analog switch, 31... Camera, 35.. Slave transmission frame assembly / separation circuit (encapsulation means, impedance control section), 36 .. LAN physical layer construction section, 37 .. Wideband analog switch (impedance switching means), 41 ..Display, 45..Base unit transmission frame assembly / separation circuit (encapsulation means, impedance control unit), 6 .. LAN physical layer construction unit, 47 ... wideband analog switch (impedance switching means).

Claims (4)

An interphone system in which an interphone slave unit having a function of calling and calling a resident and an interphone master unit having a function of responding to a call are connected using a physical layer of a local area network,
The interphone slave unit and the interphone master unit are respectively connected to a pair of transmission lines each having a transmission terminal and a reception terminal among transmission lines constituting the physical layer,
Encapsulating means for encapsulating transmission data such as call data in both preamble and idle used in the MAC frame of the local area network,
Impedance switching means for switching between high and low impedance of the transmission line;
An impedance control unit for switching and controlling the impedance switching means;
The impedance control unit switches the impedance at a predetermined timing to enable communication of the encapsulated transmission data, and performs half-duplex communication between the interphone slave unit and the interphone master unit. Intercom system to do. A surveillance camera system in which a surveillance camera device for imaging a suspicious person and the like and a monitor device for displaying a captured image of the surveillance camera device are connected using a physical layer of a local area network,
The monitoring camera device and the monitoring device are each connected to a pair of transmission lines each having a transmission terminal and a reception terminal among transmission lines constituting the physical layer,
The monitoring camera device is provided with an encapsulating means for encapsulating video data to be transmitted with a preamble and an idle used in the MAC frame of the local area network, and the monitoring device has a MAC frame of the local area network. Encapsulating means for encapsulating camera control data such as zoom, pan / tilt, etc. transmitted with preamble and idle used in
Furthermore, an impedance switching means for switching the impedance of the transmission line between high and low, and an impedance control unit for switching and controlling the impedance switching means, respectively,
The impedance control unit switches the impedance at a predetermined timing to enable transmission of the encapsulated video data and control data, and performs half-duplex communication between the monitoring camera device and the monitoring device. Characteristic surveillance camera system. 2. The intercom system according to claim 1, wherein the impedance switching means is a broadband analog switch. The surveillance camera system according to claim 2, wherein the impedance switching means is a wideband analog switch.

Images