JPH02214366A - Interphone set with monitor - Google Patents

Abstract

PURPOSE:To connect plural interphone slave sets to one interphone master set by sending a specific control signal sent from each interphone slave set to a master set when a call switch is depressed, detecting the control signal and identifying which interphone slave set gives a call. CONSTITUTION:When no call switch SW1 of any interphone slave set 2 is depressed, a low voltage power supply is supplied from a power supply circuit of an interphone master set. Thus, an output of a voltage discrimination circuit DCC is at a low level. When the call switch SW1 of any interphone slave set 2 is depressed, a call signal Vs is outputted from a modulator MD2 and a carrier transmission signal Vs' is sent in frequency multiplex and a specific control signal VH is inserted in a prescribed period of a monitor video signal Vp and sent to the interphone master set. The carrier transmission signal Vs' is detected by a demodulator of the interphone master set, a call bell rings to inform the presence of a call.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an intercom device with a monitor that monitors visitors using a monitor camera and a monitor television.

[Prior Art] Conventionally, this type of intercom device with a monitor, which monitors visitors using a monitor camera and a monitor television, is
As shown in the figure, this intercom device was composed of an intercom slave unit 2 equipped with a monitor camera 1 and an intercom base unit 5 equipped with a monitor television 4 that displayed a monitor image taken by the monitor camera 1. Here, an intercom communication line 3a consisting of a pair of wires transmits an intercom communication signal, and a coaxial cable 3 that transmits a monitor image signal.
The intercom slave unit 2 and the intercom base unit 5 were connected by the terminal b. For this reason, when installing an intercom device with a monitor instead of the existing intercom device, it is necessary to newly wire the coaxial cable 3b, which poses a problem that construction becomes troublesome. Furthermore, there was a problem in that the added coaxial cable 3b was conspicuous and unsightly.

Therefore, as a method for solving these problems, there is a method described in Japanese Patent Application No. 158361/1982 and Japanese Patent Application No. 260039/1982. In these intercom devices with a monitor, as shown in FIG. By frequency multiplexing the intercom call signal Vi2 transmitted to 2,
As shown in FIG. 11, it is possible to configure the wiring between the intercom slave unit 2 and the intercom base unit 5 using only pair wires 3a. In addition, V il in FIG.
', Vi2' are intercom call signals Vi1. Vi
This is a carrier transmission signal in which V.sub.2 is superimposed on a carrier wave having a relatively low frequency outside the frequency band of the monitor image signal Vp.

[Problems to be Solved by the Invention] However, in the conventional example such as the above-mentioned Japanese Patent Application No. 158361/1983, only one intercom magic trick 2 can be connected to one intercom base unit 5. There was a problem in that it was not possible to connect a plurality of intercom slave units 2 to one intercom base unit 5, which is required in buildings, condominiums, homes, etc. that have multiple entrances and exits.

The present invention has been made in view of the above points, and its purpose is to connect a plurality of intercom slave units to one intercom base unit, and to connect each intercom slave unit to a single intercom base unit. An object of the present invention is to provide an intercom device with a monitor that can transmit a control signal for recognizing a call without widening the transmission band.

[Means for Solving the Problems] A monitor-equipped intercom device of the present invention includes a plurality of intercom handsets each equipped with a monitor camera, and one monitor television equipped with a monitor image that displays a monitor image photographed by the monitor camera. The monitor image signal, the intercom call signal, and the call switch signal are used as baseband transmission signals, and the other signal is a relatively low frequency band outside the baseband signal. Control that is sent from each intercom slave unit to the base unit when a call switch is pressed in a monitor-equipped intercom device that transmits frequency multiplexed carrier transmission signals superimposed on a frequency carrier wave via a pair of signal lines. Each intercom slave unit is provided with a control signal transmission means for inserting a signal into a monitor video signal during a predetermined period assigned to each intercom slave unit, and the control signal is detected to determine which intercom slave unit is calling. The intercom main unit is equipped with a control signal detection means for identifying the intercom.

[Function] The present invention is configured as described above, and transmits a monitor image signal, an intercom call signal, and a call switch signal transmitted between an intercom slave unit and an intercom base unit through a signal line consisting of a pair of wires. In a monitor-equipped intercom device that performs frequency multiplexed transmission, when the call switch is pressed, a unique control signal sent from each intercom slave unit to the base unit is transmitted to a predetermined control signal assigned to each intercom slave unit of the monitor video signal. It is inserted into the intercom period and transmitted, and this control signal is detected to identify which intercom handset the call is from.
Multiple intercom handsets can be connected to one intercom base unit, and control signals for recognizing calls from each intercom handset can be transmitted without expanding the transmission band. .

[Embodiment] FIGS. 1 to 5 show an embodiment of the present invention. As shown in FIG. The intercom main unit 5 includes N units of intercom slave units 2 and one intercom base unit 5 equipped with a monitor television 4 that displays a monitor image photographed by a monitor camera 1. Here, the intercom handset 2 is connected to the monitor camera 1 as shown in FIG.
In addition, it is provided with a call switch SW for calling the intercom base unit 5, a microphone MC for communicating with the intercom base unit 5, and a speaker SPI. On the other hand, as shown in FIG. 3, the intercom base unit 5 includes a handset 12 (microphone MC! in FIG. 3) for communicating with the intercom handset 2 in addition to the monitor TV 4.
and speaker PS2. ), a call bell 11 to notify that there is a call from an intercom handset 2, and displays LD, to LDH for specifically displaying the intercom handset 2 that has received a call.

The intercom handset 2 includes a transmission circuit 6s that transmits the monitor image signal Vp of the monitor camera 1, the intercom call signal Vil, the calling signal Vs, and the control signal ■9 specific to the handset 2 to the intercom base unit 5. , and a receiving circuit 6b that receives an intercom call signal Via transmitted from the intercom base unit 5.

The intercom base unit 5 also includes a receiving circuit 7a that separates and extracts the intercom call signal Vil and the monitor image signal Vp from the transmission signal of the intercom slave unit 2 and receives the intercom call signal Vi2 from the microphone MC. The transmitter/receiver means 7 includes a transmitter circuit 7b for transmitting data to the receiver. In other words, in this embodiment as well, the monitor image signal Vp output from the television camera 1 is transmitted as a baseband transmission signal to the intercom base unit 5, and the intercom of the microphone MC is transmitted as a baseband transmission signal. It transmits the call signal vi1 to the intercom parent 15 as a carrier transmission signal Vi1'' superimposed on a carrier wave of a relatively low frequency outside the frequency band of the monitor image signal Vp, and also transmits the intercom call signal Vi2 of the microphone MC, and the calling signal Vs. carrier transmission signal vi
2' is transmitted to the intercom handset 2 as carrier transmission signals Vi, ', Vs' superimposed on a carrier wave with a higher frequency than that of carrier wave 2', thereby performing frequency multiplex transmission. Therefore, in this embodiment as well, the intercom slave unit 2 and the intercom base unit 5 can be connected only by the intercom communication line 3a made of a bare wire, and therefore the installation is easy and the wiring is not noticeable.

In addition, in the case of this embodiment, a plurality of intercom handsets 2
The intercom communication line 3a is wired in the form of a bus as shown in FIG.

Further, transmitting circuits 6m, 7b and receiving circuit 6b for intercom handset 2 and intercom main unit 5.

The configuration of 6a will be explained. The transmission circuit 6a of the intercom handset 2 includes a low frequency amplifier A that amplifies the intercom call signal ViI output from the microphone MC, a modulation circuit MD that modulates the carrier wave with the intercom call signal ViI, and a call switch SW1. A modulator MD2 modulates with a signal Vs when the button is pressed (turned on), a carrier transmission signal V;, T output from the modulator MD, and a modulator MD.

The mixer MIX mixes the carrier transmission signal Vs' output from the mixer MIX with the monitor image signal Vp, and the amplifier A amplifies the frequency multiplexed signal Vip output from the mixer MIX and sends it to the intercom communication line 3a. It is.

The receiving circuit 6b includes an amplifier A3 that amplifies the signal transmitted via the intercom communication line 3a, a bandpass filter BPF that extracts the carrier transmission signal ■12° from the intercom base unit 5, and a carrier transmission signal Vi2°. a demodulator DM that demodulates the intercom call signal vi2 from the speaker SP;
1 and a low frequency amplifier A4 that drives the 1.

Further, the reception circuit 7a of the intercom base unit 5 includes an amplifier A6 that amplifies the signal transmitted via the intercom communication line 3a, and a monitor image signal V from the output of this amplifier A.
A video filter F1 that extracts p and a monitor image signal Vp
a video amplifier A7 that amplifies and inputs the signal to the monitor television 4; a bandpass filter BPF that extracts the carrier transmission signal Vi, °; a demodulator DM2 that demodulates the intercom call signal Vi1 from the carrier transmission signal Vi1; A low frequency amplifier A that amplifies the call signal vi and drives the speaker SP2, a bandpass filter BPFs that extracts the carrier transmission signal Vs', and a demodulator that demodulates the calling signal Vs from the carrier transmission signal Vs'. The transmitting circuit 7b consists of a microphone M.
A low frequency amplifier A that amplifies the intercom call signal vi2 output from Cz, and a modulator MD that modulates the carrier wave with the intercom call signal Vi2.

and the carrier transmission signal V which is the output of this modulator MD.
An amplifier A amplifies ia' and sends it to the intercom communication line 3a. It consists of

In addition, in the intercom device with a monitor of this embodiment, there is a constant alarm voltage circuit P that constants the DC power supply to a predetermined voltage, and a power supply that controls the supply of the output of this constant voltage circuit P to the intercom handset 2. A circuit PS is provided in the intercom base unit 5, and a DC separation circuit DC is provided in the intercom slave unit to obtain circuit power by separating the DC voltage supplied via the interphone communication line 31 from the signal. Power is supplied to the intercom handset 2 via the intercom communication line 3a.

By the way, since the present embodiment includes a plurality of intercom slave units 2, it is necessary to make it possible for the intercom base unit 5 to know which intercom slave unit 2 is making a call. Therefore, unique control signals v and I indicating that the call switch SWl has been pressed are transmitted from each intercom handset 2 to the intercom base unit 5, and the transmission of this control signal VN is controlled by the control signal transmission means. 8
In this embodiment, the control signal Vw is inserted into each intercom handset 2 into a predetermined line (1st to 20th line) of the vertical blanking period of the monitor video signal Vp, and the call switch SW1 is inserted. The intercom handset 2 on which is pressed is identified. This control signal V. The control signal transmission means 8 transmits the horizontal synchronization signal outputted from the dip switch DSW that sets a unique line number for each intercom handset 2 and the synchronization signal generation circuit SG in the camera 1 to the vertical retrace line. A line counter LC that counts immediately after the period signal, a comparator CMP that compares the output of the line counter LC5 and the set value of the dip switch DSW, and a display period signal of a predetermined line based on a coincidence output from the comparator CMP and a horizontal synchronization signal. It is composed of an AND circuit AND2 and an analog switch ASW controlled by the output of the AND circuit AN There is.

On the other hand, intercom base unit 5 side has intercom slave unit 2.
Monitor video signal V including control signal ■7 sent from
A control signal detection means 10 is provided for detecting a control signal vH from a video filter F, and this control signal detection means 10 includes a synchronization separation circuit for extracting horizontal and vertical synchronization signals from a monitor video signal Vp extracted by a video filter F. SS, a line counter LC2 that counts the number of lines based on a horizontal synchronization signal, a comparator CMP2 that detects a control signal from a monitor video signal Vp, and a line counter L
It is composed of a decode latch circuit DL that decodes the count value output from C2 and latches the decoded data when the control signal □ is detected by the comparator CM P t. The output of this decode latch circuit DL lights up the display devices LD, ~LD,
It is designed to display which intercom handset 2 has called, and the indicators LD, ~LD continue to light up until the handset 12 of the intercom base unit 5 is on-hook, and then the handset 12 is turned on-hook. When the hook switch H3 is turned off, the decode latch circuit DL is reset and the light is turned off.

Further, the call bell 11 is designed to ring when there is a call from any of the intercom handsets 2.

Furthermore, in this embodiment, when there are no visitors, the monitor camera 1 is kept inactive, the call switch SW of any intercom handset 2 is pressed, and the handset 12 of the intercom main unit 5 is off-hook. The monitor camera 1 is set to operate only when the camera is opened. Therefore, the power supply circuit PS of the intercom base unit 5
The power supply voltage supplied to the intercom cordless handset 2 via the intercom communication line 3a is varied depending on the state of the hook switch H8 of the handset 12. In other words, while the handset 12 is still set, the hook switch H3
is off, the power supply circuit PS supplies a low power supply voltage, and only when the handset 12 is off-hook and the hook switch H3 is turned on does the high power supply necessary to operate the monitor camera 1 of the intercom handset 2 occur. Supply voltage. And on the intercom handset 2,
A camera power control means 9 is provided for controlling the supply of power to the monitor camera 1 according to the power supply voltage supplied from the intercom base unit 5. This camera power supply control means 9 includes a voltage judgment circuit DCC which judges whether the output voltage of the DC separation circuit DC is a high or low voltage, and a NOR which takes the output of the call switch SW1 and the output of the voltage judgment circuit 9. A circuit NOR, a latch circuit LT that latches the output of this NOR circuit NOH, and this latch circuit L.
It consists of an AND circuit AND which ANDs the output of T and the output of the voltage determination circuit DCC, and a power supply switch SW2 that supplies power to the monitor camera 1 with the output of the AND circuit AND. The output of the power supply determination circuit DCC is at a high level when the power supply voltage is high, and the power supply switch SW2 is turned on when the output of the AND circuit AND is at a high level. In addition, the control signal transmission means 8
The latch circuit LT is reset at the rising edge of the output of the voltage determination circuit DCC. In other words, when the call ends and the handset 12 of the intercom base unit 5 is turned on-hook, the latch circuit LT is reset and returns to the initial state. Furthermore, in the Noah circuit NOR, even if the call switch SW of another intercom handset 2 is pressed while a certain intercom handset 2 is calling the intercom base unit 5 and talking, the intercom handset 2 will call the intercom base unit 5 later. Power is not supplied to the monitor camera l of the intercom handset 2 that is about to make a call, so that no interference occurs in the monitor image sent from the intercom handset 2 to the intercom base unit 5 during the call. be. In other words, when the handset 12 of the intercom base unit 5 is off-hook in response to a call from a certain intercom slave unit 2, the outputs of the voltage judgment circuits DCC of all the intercom slave units 2 become high level, so this NOR circuit NOH causes other The input to the latch circuit LT of the call switch SW of the intercom handset 2 is blocked, the output of the latch circuit LT is inverted, and power is not supplied to the monitor camera 1.

The operation of this embodiment will be explained below. First, when none of the intercom slave units 2 presses the call switch SW+, low voltage power is supplied from the power supply circuit PS of the intercom base unit 5. Therefore, voltage determination circuit D
The output of CC is at low level. Now, when the call switch SW of a certain intercom handset 2 is pressed,
Modulator MD.

outputs the calling signal Vs from the carrier transmission signal Vs
' is frequency multiplexed and transmitted, and a unique control signal V
ll is inserted into a predetermined period of the monitor video signal Vp and transmitted to the intercom base unit 5.

Note that at the same time, the output of the NOR circuit NOR becomes high level, and the output state of this NOR circuit NOH is latched by the latch circuit LT.

This carrier transmission signal vS' is detected by the demodulator DM of the intercom base unit 5, and the call bell 11 rings to notify that there is a call.

At this time, as shown in FIG. Control signal V on the line. The indicator LD corresponding to the value of the synchronization counter is lit depending on whether the value of the synchronization counter is sent.
This display device LD allows the user to see at a glance which intercom handset 2 is calling. In Fig. 4, the setting value by dip switch DSW is “1”.
1 (control signal VII is present on the first line).

Then, when a family member or the like who hears the ringing sound from the calling bell 11 takes the handset 12 of the intercom base unit 5 off-hook, the hook switch HS is turned on, the ringing sound is stopped, and a high voltage power is supplied from the power supply circuit PS to the intercom base unit 5. The signal is supplied to the slave unit 2.

When a high voltage power source is supplied to the intercom handset 2 in this way, the output of the voltage determination circuit DCC becomes high level, so that the call switch SW is activated.

In the intercom handset 2 where the button is pressed, the output of the AND circuit AND becomes high level, the power supply switch SW2 is turned on, and power is supplied to the monitor camera 1. Thereafter, the monitor image signal Vp of the monitor camera 1 and the intercom communication signals Vil, Vi2 are transmitted and received in both directions via the intercom communication line 3m, and the customer can interact with the visitor while viewing the image on the monitor television 4. At this time, even if the call switch SW1 is pressed on another intercom handset 2, the input of the call switch SWI of that intercom handset 2 is blocked by the NOR circuit NOR as described above. 2 monitor camera 1
The monitor image signal Vp of the other monitor camera 1 will not interfere with the monitor image signal Vp of the intercom handset 2 that is currently being transmitted.

After the call ends, the handset 1 of the intercom base unit 5
2 is turned on-hook, the hook switch H3 is turned off, and the voltage of the power supplied from the power supply circuit PS to the intercom handset 2 becomes low. At this time, the decode latch circuit DL is also reset by turning off the hook switch H8, and the display device LD is turned off. As described above, when the voltage of the power supplied from the power supply circuit PS to the intercom handset 2 becomes low, the output of the voltage judgment circuit DCC of the intercom handset 2 becomes low level, so the power supply switch SW2 is turned off. Then, the power supply to the monitor camera 1 is cut off, and the latch circuit LT is reset to return to the initial state.

By the way, in the above embodiment, the monitor image signal Vp is used as a baseband transmission signal, and the intercom call signal is used as a carrier transmission signal, but the reverse may be used. Also, the power supply of the monitor camera 1 can be controlled by the camera power supply control means 9. Therefore, even if the call switch SW1 is pressed on another intercom handset 2 while a certain intercom handset 2 is talking with the intercom base unit 5, the monitor camera 1
The monitor image signal Vp is
In the same way, microphone M
C. By controlling the power supply to the speaker SPI, it is also possible to prevent intercom call signals from overlapping.

In addition, in this embodiment, the dip switch DSW is used as a binary data input means, and the input numerical value is made to correspond to the line number of the display line, but each bit of the dip switch is made to correspond to the line number (bit switch ``1'' → line number ``1'', bit switch ``2'' → line number ''2n
・・・・・・・・・・・・)

6 and 7 show other embodiments, in which the predetermined period in which the control signal V is inserted is set to a period of 3 or more lines (4 lines in the embodiment) within the vertical retrace period of the monitor video signal Vp. ), and the control signal 7 is inserted in the center (second line in the embodiment) excluding the lines at both ends of the predetermined period. Here, the lower two bits of the line counter LC are ignored and the remaining upper bits are sent to the comparator CMP.
.

(excluding the lower 2 bits), the lower 2 bit input of the comparator CMP is set to 10'', and the control signal V is inserted into the second line of a predetermined period consisting of 4 lines.

On the other hand, line counter L C2 on the intercom base unit 5 side
The lower two bits of the output are released, and the remaining upper bits are decoded by the decode latch circuit DL, and the intercom handset 2 whose call switch SW1 has been pressed is notified by lighting the display elements LD, ~LDw. It has become.

Figure 8 shows "1'" of the five intercom slave units 2.
This shows the case when the call switch SW Also, the intercom handset 2's
When the call switch SW “2” is pressed,
A control signal (2) will be inserted into line "6".

As described above, in this embodiment, the control signal ■8 is inserted into the center (second line in the embodiment) excluding both end lines of a predetermined period consisting of three lines (four lines in the embodiment). Therefore, even if noise is mixed into the monitor video signal Vp and the horizontal synchronization signal is slightly omitted (the noise is misidentified as a synchronization pulse, or the synchronization pulse is missing), the intercom when the call switch SWI is pressed The handset 2 can now be identified normally.

[Effects of the Invention] The present invention is configured as described above, and the monitor image signal, intercom call signal, and call switch signal transmitted between the intercom slave unit and the intercom base unit are transmitted through a signal line consisting of a pair of wires. In a monitor-equipped intercom device that performs frequency multiplexed transmission via a monitor video signal, a unique control signal sent from each intercom slave unit to the base unit when the call switch is pressed is assigned to each intercom slave unit of the monitor video signal. It is inserted and transmitted during a predetermined period of time, and this control signal is detected to identify which intercom handset the call is from.
A plurality of intercom slave units can be connected to one intercom base unit, and a control signal for recognizing a call from each intercom slave unit can be transmitted without widening the transmission band.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the overall configuration of an embodiment of the present invention, FIG. 2 is a block circuit diagram of the same intercom handset,
FIG. 3 is a block circuit diagram of the intercom base unit same as above, FIG. 4 is an explanatory diagram of a monitor video signal including the control signal same as above,
FIG. 5 is an explanatory diagram showing the frequency spectrum of the transmission signal same as above, FIG. 6 is a block circuit diagram of an intercom slave unit of another embodiment, FIG. 7 is a block circuit diagram of an intercom base unit same as above, and FIG. 8 is an explanatory diagram of a monitor video signal including the same control signal as above, FIG. 9 is a schematic configuration diagram of a conventional example, FIG. 10 is an explanatory diagram showing the frequency spectrum of a transmission signal of another conventional example, and FIG. It is a schematic block diagram. 1 is a monitor camera, 2 is an intercom slave, 3 is a signal line, 4 is a monitor television, 5 is an intercom base unit, 6.7 is a transmitting/receiving means, 8 is a control signal transmitting means, and 10 is a control signal detecting means. Agent Patent Attorney Ishi 1) Long Figure 7 1?

Claims (2)

[Claims] (1) Consisting of multiple intercom slave units equipped with monitor cameras and one intercom base unit equipped with a monitor TV that displays monitor images taken by the monitor camera, the intercom base unit is equipped with monitor image signals and intercom call signals. and a call switch signal, one of which is a baseband transmission signal, and the other signal is a carrier transmission signal superimposed on a relatively low frequency carrier wave outside the frequency band of the baseband signal, which is a signal formed by a pair of wires. In a monitor-equipped intercom device that transmits frequency multiplexed signals via wires, the control signal sent from each intercom slave unit to the base unit when a call switch is pressed is a predetermined signal assigned to each intercom slave unit of the monitor video signal. Each intercom slave unit is provided with a control signal transmission means to be inserted into the period, and the intercom base unit is provided with a control signal detection means for detecting the control signal and identifying which intercom slave unit is calling. An intercom device with a monitor featuring: (2) Claim 1 characterized in that the predetermined period is a period of three or more lines within a vertical retrace period of the monitor video signal, and the control signal is inserted in the center of the predetermined period excluding lines at both ends. Intercom device with monitor as described.