JP3491692B2 - 2-wire TV intercom system with electric lock control function - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-wire television intercom system, and more particularly, to an existing television intercom system even when an electric locking / unlocking system is added. The present invention relates to a device having a feature that it can be easily constructed by using the same wiring. 2. Description of the Related Art Recently, as shown in FIG. 10, a door phone handset 200 having a television camera installed at a front entrance.
And a two-wire television intercom system configured by connecting the intercom base unit 100 having a monitor television installed on the indoor side via a pair of signal lines L100 has been developed and used. However, in such a system, it is possible to respond appropriately while watching the visitor's appearance on the monitor television, and wiring work is facilitated because it is only necessary to lay a pair of signal lines L100. . Further, unlike such a system, as shown in FIG. 11, an electric lock 300 provided at a front door is provided.
And a secret operating device 400 installed at the entrance and an electric lock operating device 500 installed at the indoor side with a pair of signal lines L.
A two-wire electric locking / unlocking system configured to be connected via the 200 has also been used.
In the system, the door can be locked and unlocked while staying in the dwelling unit, so that it is possible to promptly respond to customers. By the way, in general, it is customary to perform a door interlock operation after confirming a visitor with a TV intercom system or the like. Therefore, the TV intercom system and the electric locking / unlocking system are integrally installed. Systems have been developed that can be added or added. [0005] Fig. 12 shows an example of the configuration of such an integrated system.
4. A sign post 800 integrally provided with the functions of the TV camera 802, the intercom 801 and the secret operation device 803 is installed, and the electric lock 300 attached to the entrance door and the TV intercom master unit 600 installed in the dwelling unit ( 700) and the electric lock operation unit 500, wirings L100 and L200 are laid. In such a system, there is no need to separately install a secret operating device and a TV door phone slave unit at the entrance, and even if an electric locking / unlocking system is added,
Just by adding the electric lock 300 and the electric lock operation unit 500, there is no need to newly install a secret operation device,
The workability has been improved. However, in such a system, it is possible to improve the workability by using the sign post 800. However, the wiring L100, L100 and the electric lock operation unit 500 are respectively connected between the indoor intercom master unit 600 and the electric lock operation unit 500. L20
0 had to be laid individually, and the construction was troublesome, so improvement was desired. SUMMARY OF THE INVENTION The present invention has been proposed in view of the above circumstances. Even when an electric locking / unlocking system or the like is added, it is easy to use the wiring of the existing intercom system in common. It is an object of the present invention to provide a two-wire electric lock system that can be installed in a computer. According to the first aspect of the present invention, there is provided a two-wire television intercom system, comprising: an electric lock unit; And a television intercom master unit having a monitor television connected by a pair of common signal lines, in the two-wire television intercom system, the electric lock unit and the intercom slave unit are a second pair of In addition to being connected by a common signal line, the intercom slave unit and the TV intercom master unit are connected by a first pair of common signal lines, and the TV intercom master unit is connected from the intercom slave unit to the second unit. A video processing unit for receiving a video signal transmitted through one common signal line and displaying a video on a monitor television; A call processing unit for receiving a call signal transmitted through a common signal line and outputting the received call signal, and transmitting an input call signal to the intercom slave unit through the first common signal line; A control signal for controlling the energization of the television camera and controlling the locking and unlocking of the electric lock unit is transmitted through the first and second common signal lines, and the second and second control signals are transmitted from the electric lock unit side. A control processing unit for receiving and receiving the lock state detection signal transmitted through the first common signal line and displaying the unlock state; and outputting the signals output from the processing units to the first and second control units. Via the common signal line, to the doorphone slave unit side and the electric lock unit side, superimposed on a DC power supply and transmitted by the frequency multiplexing modulation method, while transmitting each signal transmitted by the frequency multiplexing modulation method, Multiplex transmission processing unit for transmitting to each processing unit, the intercom slave unit has a TV camera, the video signal captured by the TV camera, to the TV intercom master unit side, the second A video processing unit for transmitting through a common signal line, a speaker and a microphone, and receiving a call signal transmitted through the first common signal line from the main unit of the television interphone and outputting the signal from the speaker A telephone call processing unit for transmitting a telephone call signal input from a microphone to the television intercom master unit side through the first common signal line; and a control signal corresponding to a password input by the numeric keypad. To the electric lock unit through the second common signal line, and the television intercom master unit and the electric lock unit. In addition, the first and second
A connection terminal for a base unit connected via a common signal line of
A lock unit connection terminal, and a signal output from each of the processing units is connected to the electric lock unit side and the television intercom master unit side by a frequency multiplexing modulation method. , While receiving the signals transmitted from the TV intercom master unit and the electric lock unit by the frequency multiplex modulation method through the first and second common signal lines and transmitting the signals to the respective processing units. A multiplex transmission processing unit, connected to the multiplex transmission processing unit, and connected to the first
And a power supply separation circuit for separating and outputting the DC power transmitted through the common signal of the electronic lock unit. The electric lock unit is configured to transmit a password transmitted from the intercom slave through the second common signal line. A lock control processing unit that performs number match determination and performs lock / unlock control of the lock when the lock / unlock control signal is transmitted from the TV intercom master via the first and second common signal lines. A lock state detection processing unit for detecting the locked / unlocked state of the lock and transmitting a lock state detection signal to the main unit of the television intercom; and a signal output from the lock state detection processing unit having a slave terminal connection terminal. Is transmitted to the main unit of the television intercom via the second and first common signal lines by the frequency multiplexing modulation method, while the intercom slave unit and the television set are transmitted by the frequency multiplexing modulation method. A multiplex transmission processing unit for transmitting each signal transmitted from the telephone main unit via the first and second common signal lines to the lock control processing unit; and a multiplex transmission processing unit connected to the multiplex transmission processing unit, 1, a power supply separation circuit for separating and outputting the DC power transmitted from the television intercom master unit via the second common signal line. In the TV intercom system of the present invention, the TV intercom master unit and the doorphone slave unit are connected via a first pair of common signal lines to form a two-wire TV intercom system. In addition, a two-wire TV intercom system combining an electric lock and a TV interphone can be easily realized by simply additionally connecting an electric lock unit serially to the system via a second common signal line. . Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the internal configuration of a television intercom master unit 1. In FIG. 1, reference numeral 10 denotes a video processing unit for receiving a video signal transmitted from a slave unit, which will be described later, and displaying a video; Is a call processing unit for transmitting / receiving a call signal to / from the slave unit, and 12 is a control unit for sending a control signal to the slave unit or an electric lock unit (described later), and a control signal transmitted from the electric lock unit side. The control processing unit 13 for receiving and processing signals receives the signals transmitted and received on the processing units described above via the first pair of common signal lines L via the doorphone slave device.
2. Connection terminal for slave unit for transmission to electric lock unit 3 side
A multiplex transmission processing unit having a child TA (in this embodiment, a balanced transmission circuit is used), and 14 is a signal processing unit that centralizes the signal processing of each unit. Incidentally, 15 is a constant voltage power supply circuit for supplying power to the internal circuit each unit of the main unit 1, the DC power outputted from the constant voltage power supply circuit 15, first through the power line circuit 16 and the balanced transmission circuit 13
The power is supplied to the slave unit and the electric lock unit via one common signal line L. Here, in the frequency multiplex modulation method in the present embodiment, as shown in FIG. 2, the video signal transmitted from the slave unit 2 is not modulated and is a baseband having a frequency band of 0 to f1. is transmitted, the call of the call signal to the main unit 1 child device 2 side is transmitted to the carrier frequency f2 to frequency modulation (FM modulation) (base unit call modulated signal), the slave unit 2 side to the main unit 1 signal is transmitted by frequency modulating the carrier frequency f3 (slave unit call modulated signal), the master unit 1 and slave unit 2
Alternatively, the control signal transmitted to and from the electric lock unit 3 is transmitted by amplitude-modulating the carrier of the frequency f4 as described later (control modulation signal). In addition, in addition to the communication signal of several tens Hz to several KHz, the handset communication modulation signal has about 20 K
A tone signal having a frequency of Hz is added. The video signal processing unit 10 of the base unit 1 includes a low-pass filter (LPF) 10a from the frequency-multiplexed modulated signals transmitted through the balanced transmission circuit 13 via the common signal line L. Accordingly, a video signal component lower than the frequency f1 is extracted, the extracted video signal is amplified by the video signal amplifier circuit 10b, and the video is displayed on the monitor television 10c. Reference numeral 10d denotes an energization control circuit that controls energization of the monitor television 10c and the video signal amplifier circuit 10b when a monitor switch described later is operated or a call switch is operated on the slave unit side. The speech processing unit 11 amplifies the voice signal input by the handset H by the amplifier circuit 11i, FM modulates the carrier of the frequency f2 by the modulation circuit 11h, and sets the band pass filter B. P. The center frequency is changed to f2 by F11g.
Is transmitted to the common signal line L side, while the handset communication modulation signal transmitted from the handset side is
B. P. The signal of the center frequency f3 is extracted by F11a, demodulated by the demodulation circuit 11b, amplified by the amplification circuit 11c, and output as sound by the handset H. As will be described later, if the calling switch is operated on the slave unit side and the demodulated signal contains a 20 kHz tone signal, the tone signal is detected by the tone signal detecting circuit 11d and the calling signal generating circuit 1 is detected.
A calling signal is transmitted from 1e to the speaker 11f, and a ringing sound is output. When the monitor switch 12h and the locking / unlocking operation key 12i of the key operation unit 12g are operated, the control processing unit 12 generates a code signal corresponding to the operation from the encoder 12f, amplitude-modulates the carrier of the frequency f4, and generates the code signal. The control modulation signal obtained by B.I. P. The signal is output to the common signal line L through F12a. When a lock state detection signal and an open door detection signal are transmitted via the common signal line L, B.B. P. The signal is received through the F12a, demodulated by the demodulation circuit 12b, decoded by the decoder 12c, and the corresponding indicator lamp of the display unit 12d is driven to light. Here, as shown in FIG. 3A, the code signal generated by the encoder 12f is such that bit data 0 outputs a signal of a predetermined frequency for 1 ms, and bit data 1 outputs a signal of the same frequency. Is output for 2 ms. When a key operation is performed by the key operation unit 12g as shown in FIG. 3B, a 10-bit code signal which is predetermined corresponding to the key is output. Is transmitted (in this embodiment, three consecutive transmissions are performed). The balanced transmission circuit 13 is used to prevent unbalanced signals such as a video signal, a speech modulation signal, and a control modulation signal from being transmitted through a pair of wires, thereby preventing the degree of balance from being lost and increasing the amount of noise. In this embodiment, as shown in FIG. 4, an impedance compensating circuit 13b is added to a conventional balun 13a to stabilize the impedance between terminals. FIG. 5 shows an example of the configuration of a door phone handset 2 according to the present invention . In FIG.
A power supply separating circuit for separating and outputting a DC power transmitted from the side via the common signal line L, a video processing unit 21 for transmitting a video signal of the television camera 21a to the base unit 1, and a reference numeral 22 for the base unit
A call processing unit for transmitting and receiving a call signal to and from the second
A secret processing unit for transmitting a control signal corresponding to a password to an electric lock unit (to be described later) connected via a common signal line L 'of the first and second pairs of first and second common signals;
Via the lines L and L 'to the master unit 1 and the electric lock unit 3 side.
Connection terminal TB for master unit for sending, connection end for lock unit
A multiplex transmission processing unit having a child TC (in the present embodiment, the above-described balanced transmission circuit is used), and 25 is a signal processing unit that centralizes signal processing of each unit. The video processing section 21 amplifies a video signal captured by the television camera 21a by a video signal amplifying circuit 21b. P. F21c transmits only the video signal component lower than the frequency f1 to the base unit 1 in the baseband in which no modulation is performed, and transmits the control modulation signal (frequency f4) transmitted via the common signal line L to the B.F.
P. The demodulation circuit 21e demodulates the control code through F21d, the control code is demodulated by the decoder 21f, and the energization control circuit 21g controls the energization of the television camera 21a. The speech processing section 22 amplifies the audio signal collected by the microphone 22e by an amplifier circuit 22f,
FM modulates the carrier of the frequency f3 with g, passes only a predetermined band of the center frequency f3 with the band-pass filter 22h, sends it out to the master unit 1 side as a slave unit communication modulation signal, and is transmitted from the master unit 1 side. The incoming master facsimile modulation signal of frequency f2 is supplied to bandpass filter B. P. The signal is demodulated by the demodulation circuit 22b via the F22a, amplified by the amplification circuit 22c, and output from the speaker 22d. When the call switch 22j is operated, a tone signal of about 20 KHz is output from the tone signal generation circuit 22i and sent to the base unit 1 as a slave unit communication modulation signal to control ringing of a ringing tone. It has become. When the secret processing unit 23 operates the secret key 23a to input a password, a code signal (see FIG. 3) corresponding to the password is transmitted from the encoder 23b to the modulation circuit 23c. A control modulation signal obtained by amplitude-modulating the carrier having the center frequency f4 is represented by B.C. P. The signal is transmitted to the electric lock unit connected to the common signal line L 'via F23d. FIG. 6 shows an example of the configuration of the electric lock unit 3. In FIG. 6, reference numeral 30 denotes a power supply separating circuit for separating and outputting the DC power transmitted from the master unit 1, and 31 denotes a slave unit 2 side. At the time of identification of the password transmitted from
When the locking / unlocking control signal is transmitted from the
The lock control unit 32 controls the locking / unlocking of the lock 33. The lock control unit 32 detects the locked / unlocked state of the lock 33, sends a lock state detection signal to the master unit 1, and an open door detection sensor provided on the door to which the lock 33 is attached. A lock state detection processing unit that receives an open door detection signal transmitted from the lock unit (not shown) and sends an open door detection signal to the base unit 1;
Reference numeral 34 denotes a signal output from the lock state detection processing unit 32 as a second
Connected to the intercom slave unit 2 for transmission to the base unit 1 by the frequency multiplexing modulation method via the pair of common signal lines L ′.
The lock control processing unit 31 has a slave terminal TD to be transmitted and transmits a signal transmitted by the frequency multiplex modulation method.
A multiplex transmission processing unit (in this embodiment, a balanced transmission circuit is used), and a band-pass filter 35 for passing signals of a predetermined bandwidth above and below the center frequency f4. A demodulation circuit 31a receives a control modulation signal transmitted from the slave unit 2, demodulates the control signal with a demodulation circuit 31a, decodes the demodulated control signal with a decoder 31b to obtain a password, and obtains a password. When the password matches the password set in the lock control circuit 31c in advance, the lock control is performed on the lock 33 while the lock signal or the unlock signal is transmitted from the master unit 1 by the control modulation signal. The lock state detection processing section 32 detects the locked / unlocked state of the lock 33 with a lock state detection circuit 32a and encodes it with an encoder 32b. Modulated by the control signal circuit 3
At 2c, a carrier of frequency f4 is amplitude-modulated to generate a control modulation signal, which is transmitted to the master unit 1 side. FIG. 7 shows an example of a system configuration using the above-described TV intercom master unit 1, door phone slave unit 2, and electric lock unit 3 (corresponding to claim 8). The same reference numerals are given and the description is omitted. In such a system of the present invention, the master unit 1 and the slave unit 2
You of course can be used as a television interphone system by connecting the door in a first common signal line L, the child device 2
By simply adding the electric lock unit 3 via the second common signal line L ', it becomes possible to provide a TV intercom system having an electric lock control function. It can be greatly improved. Next, referring to FIG. 1, FIG. 5, FIG. 6, and FIG. 7, the schematic operation of the television intercom system having the electric lock control function of the present invention will be described. 1. Operation when the visitor operates the call switch of the slave unit. When the call switch 22j of the slave unit 2 is operated, the tone signal generated by the tone signal generation circuit 22i is transmitted to the signal processing unit 25, and the energization control circuit 21g of the video processing unit 21
While the television camera 21a is turned on, the tone signal generated by the tone signal generation circuit 22i is transmitted to the common signal line L as a control modulation signal (frequency f4). Then, in the base unit 1, the transmitted control modulation signal is demodulated by the demodulation circuit 11b of the speech processing unit 11, and the presence / absence of a tone signal is detected by the tone signal detection circuit 11d. As a result of this determination, when a tone signal is detected, the calling signal generation circuit 11e is driven to output a ringing sound from the speaker 11f, and at the same time, a detection signal is transmitted to the signal processing unit 14 so that the video processing unit 10 is turned on. The monitor television 10c is energized by the control circuit 10d to receive a video signal transmitted from the slave unit 2 and display a video. When the dweller picks up the handset H while listening to the ringing sound and watching the monitor image, the audio signal input by the handset H is transmitted to the slave unit 2 as a base station communication modulation signal (frequency f2) and demodulated. A voice signal output from the speaker 22d and input from the microphone 22e on the handset 2 is transmitted to the base unit 1 as a handset communication modulation signal (frequency f3), demodulated and output from the handset H, As a result, an intercommunication is performed. The resident confirms the visitor, and operates the lock / unlock operation switch 1 of the control processing unit 12.
When 2i is operated, the locking / unlocking control signal becomes the first and second common signal lines L and L 'as the control modulation signal (frequency f4) .
Is transmitted to the electric lock unit 3 via the
3 is unlocked. When the lock 33 is unlocked, a lock state detection signal is transmitted to the master unit 1 as a control modulation signal (frequency f4), demodulated, and the unlock state is displayed on the display unit 12d. In this case, by inputting an open detection signal of the door to which the lock 33 is attached to the lock state detection circuit 32a, it is possible to cause the display unit 12d of the main unit 1 to also perform the open display. When the call is finished and the handset H is returned to the holder F, a control signal is transmitted from the signal processing unit 14 to the energization control circuit 10d, and the energization of the monitor television 10c is cut off. A control signal is transmitted to the twelve encoders, and an energization cutoff control signal is transmitted to the slave unit 2 as a control modulation signal (frequency f4). Then, on the slave unit 2 side, the control modulation signal is demodulated, and the power supply to the television camera 21a is cut off by the power supply control circuit 21g. 2. Operation when unlocking the electric lock by operating the secret operation switch of the slave unit. When a secret number is input by operating the secret operation switch 23a of the slave unit 2, the inputted secret number is used as a control modulation signal (frequency f4) via the second common signal line L '. It is transmitted to the third side.
In the electric lock unit 3, the demodulation circuit 31a demodulates the control modulation signal, and the decoder 31b decodes the personal identification number.
When the password matches the password set in advance by the lock control circuit 31c, the lock 33 is unlocked. Then, the unlock state detection processing section 32 sends an unlock detection signal as a control modulation signal (frequency f4) to the master unit to perform unlock display. 3. Operation when turning on the TV camera by operating the monitor switch of the master unit. When the monitor switch 12h of the master unit 1 is operated, a control signal is transmitted from the key operation unit 12g to the signal processing unit 14,
The signal processing unit 14 transmits a drive signal to the energization control circuit 10d to energize the monitor television 10c. On the other hand, the control signal output from the key operation unit 12g is sent to the slave unit 2 as a control modulation signal (frequency f4) by the encoder 12f and the modulation circuit 12e. In the slave 2,
The transmitted control modulation signal is demodulated by the demodulation circuit of the video processing unit 21, and the decoder is turned on to drive the television camera 21a by the conduction control circuit 21g, whereby the video signal captured by the television camera 21a is transmitted to the master unit. Transmit to the side for projection. In this case, on the slave unit 2 side, when a predetermined time elapses, the signal processing unit 25 automatically cuts off the energizing drive of the television camera, and also on the master unit 1 side, the signal processing unit 14 automatically controls the monitor TV 10 c It is good also as composition which cuts off electricity supply. In the above description, the signal transmission is performed by the frequency multiplexing modulation method using the frequency arrangement shown in FIG. 2. However, the present invention is not limited to such a configuration. As described above, the transmission band of the two-way communication signal between the master unit 1 and the slave unit 2 is set to the baseband band of the frequency 0 to f1 ′, and the control signal is transmitted as the control modulation signal of the frequency f2 ′. And the video signal has a frequency f
It is also possible to adopt a configuration in which 3 ′ is transmitted as a modulated video signal. With such a configuration, it is necessary to adopt a configuration in which the transmission call signal is not wrapped around the reception call signal by a balance circuit (not shown) in order to bidirectionally transmit the call signal in the baseband band. It is possible to reduce the frequency bandwidth as compared with the case where signals are individually modulated and transmitted, and the common signal line L
By observing with a oscilloscope or the like, the call signal can be visually monitored. As shown in FIG. 9, the frequency f1 ″
All signals can be modulated and transmitted, such as a control modulation signal of frequency f2 ", a video modulation signal of frequency f2", a base station communication modulation signal of frequency f3 ", and a slave unit communication modulation signal of frequency f4". With such a configuration, even when the DC power supply fluctuates greatly instantaneously, the influence on other modulation signals can be minimized. According to the television intercom system of the present invention, an electric lock control function is immediately provided by simply connecting an electric lock unit serially to a television intercom system in which only the parent device and the child device are connected without adding a serving table. A TV intercom system can be configured, and the workability associated with the extension can be greatly improved.

[Brief description of the drawings] FIG. 1 is a block diagram showing an example of the configuration of a main unit of a television intercom.
is there. FIG. 2 shows the frequency of a signal transmitted by frequency multiplexing to a common signal line.
It is an example of arrangement of numbers. FIGS. 3A and 3B are illustrations showing examples of control signals;
FIG. FIG. 4 is a configuration example diagram of a multiplex transmission processing unit (balanced transmission circuit).
is there. FIG. 5Door phoneIt is an example block diagram of a slave. FIG. 6 is a block diagram illustrating an example of an electric lock unit. FIG. 7 is a schematic configuration of a television intercom system of the present invention.
FIG. FIG. 8 shows another example of a signal transmitted by frequency multiplex transmission to a common signal line.
It is a frequency arrangement example figure. FIG. 9 shows a signal that is frequency-multiplexed and transmitted to a common signal line.
It is another frequency allocation example figure. FIG. 10 is a configuration example of a conventional TV intercom system.
FIG. FIG. 11 is a configuration example of a conventional electric locking and unlocking system.
You. FIG. 12 shows a conventional TV interface having an electric locking / unlocking function.
FIG. 2 is a configuration example diagram of a telephone system. [Explanation of symbols] 1 ・ ・ ・ TV intercom master unit 10 ... Video processing unit 10c: Monitor television 11 ・ ・ ・ Call processing unit 12 Control processing unit 13 multiplex transmission processing unit (balanced transmission circuit) H ・ ・ ・ Handset L, L '...First and second pairCommon signal lineTA ・ ・ ・ Connection terminal for slave unit TB: Connection terminal for master unit TC: Connection terminal for lock unit TD: Connection terminal for slave unit 2 ...Door phoneSlave unit 20: Power supply separation circuit 21 ... Video processing unit 21a ・ ・ ・ TV camera 22: Call processing unit 22d ... speaker 22e ... microphone 23 ... Secret processing unit 23a ... numeric keypad 24 multiplex transmission processing unit (balanced transmission circuit) 3. Electric lock unit 30 ・ ・ ・ Power supply separation circuit 31 ・ ・ ・ Lock control unit 32: Lock state detection processing unit 33 ... lock 34 multiplex transmission processing unit (balanced transmission circuit)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-67088 (JP, A) JP-A-3-238997 (JP, A) JP-A-3-83446 (JP, A) JP-A 64-64 2458 (JP, A) JP-A-1-103086 (JP, A) JP-A-2-311681 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04M 9/00 H04N 7 / 18 H04Q 9/00

Claims (1)

(57) [Claims 1] A two-wire system in which an electric lock unit, a door phone slave unit, and a television intercom master unit having a monitor television are connected by a pair of common signal lines. In the television intercom system, the electric lock unit and the doorphone slave are connected by a second pair of common signal lines, and the doorphone slave and the TV interphone master are connected by a first pair of common signals. A video processing unit configured to receive a video signal transmitted from the intercom slave through the first common signal line and to display an image on a monitor television, the intercom being connected via a communication line; A call signal transmitted from the slave unit through the first common signal line is received and output as a voice, and the input call signal is transmitted to the doorphone slave unit. A call processing unit for transmitting the communication signal through a first common signal line, a control signal for controlling the energization of the television camera of the intercom slave unit, and a control signal for performing locking / unlocking control with the electric lock unit. While transmitting through a common signal line,
A control processing unit that receives and outputs a lock state detection signal transmitted from the electric lock unit via the second and first common signal lines and displays an unlocked state; and an output from each of the processing units. The signal to be transmitted is superimposed on a DC power supply via the first and second common signal lines to the doorphone slave unit side and the electric lock unit side and transmitted by a frequency multiplexing modulation method, while being transmitted by a frequency multiplexing modulation method. And a multiplex transmission processing unit for transmitting each of the transmitted signals to each of the processing units. The intercom slave unit has a television camera, and converts a video signal photographed by the television camera into the television interphone. A video processing unit transmitting to the master unit through the first common signal line; a speaker and a microphone; and a call transmitted from the TV intercom master unit through the first common signal line. A signal processing unit for transmitting a signal input from a microphone to the TV intercom master unit through the first common signal line while receiving a signal and outputting the signal from a speaker; and a numeric keypad. A secret processing unit for transmitting a control signal corresponding to the input personal identification number to the electric lock unit through the second common signal line; and a first and a second unit for the television intercom master unit and the electric lock unit, respectively. A connection terminal for the master unit and a connection terminal for the lock unit, which are connected to each other via the common signal line of the second unit. And transmitting the signal to the TV intercom master through the first and second common signal lines, while transmitting the TV interphone master and the electric lock unit. A multiplex transmission processing unit for receiving each signal transmitted from the unit by the frequency multiplex modulation method through the first and second common signal lines and transmitting the signals to the respective processing units; And a power supply separation circuit for separating and outputting a DC power transmitted from the television intercom master unit through the first common signal. The electric lock unit is configured to receive the second power from the doorphone slave unit. It determines whether the passwords transmitted through the common signal line coincide with each other. When the locking / unlocking control signal is transmitted from the main unit of the television interphone via the first and second common signal lines, the lock is locked. A lock control processing unit that controls locking and unlocking of the lock, a lock state detection processing unit that detects a locked and unlocked state of the lock, and sends a lock state detection signal to the main unit of the television intercom, and a connection terminal for a slave unit. And transmitting the signal output from the lock state detection processing unit to the television intercom master unit by the frequency multiplex modulation method via the second and first common signal lines. A multiplex transmission processing unit for transmitting each signal transmitted from the intercom slave unit and the television intercom master unit via the first and second common signal lines to the lock control processing unit; A power separation circuit connected to the transmission processing unit and configured to separate and output a DC power transmitted from the master unit of the television interphone via the first and second common signal lines; A 2-wire TV intercom system with a control function.