JP2871995B2 - TV door phone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television door intercom device, and more particularly to a television intercom device of the same construction which can be added to a single-station type TV intercom device. It relates to a door phone device.

[0002]

2. Description of the Related Art Conventionally, there is known a single-station type TV door phone apparatus in which a video signal from an entrance slave unit is monitored by a television monitor of an indoor master unit and a call can be made between the two. In this television doorphone device, an adapter-type television doorphone device shown in FIG. 6 is known to enable the indoor master unit to respond at two locations (Japanese Patent Laid-Open No. 3-83443). This TV door phone apparatus has an entrance cordless handset 61 provided with a camera eye 1, a speaker 2, a microphone 3, and a call button 4.
And an indoor parent device switching adapter 62 connected to the entrance child device 61 by a cable L ₃ , and an indoor parent device 63 branched and connected to the indoor parent device switching adapter 62 by the indoor parent device cables L ₄ and L _5. When the call button 4 of the entrance slave unit 61 is pressed, a call signal is transmitted to the indoor master units 63 and 64 via the indoor master unit switching adapter 62, and the respective television monitors 67 and 67 Is displayed on Thus, for example, when the handset 65 is off-hook by the indoor master unit 63, the indoor master unit switching adapter 62 operates, the TV monitor 67 of the indoor master unit 64 is turned off, and the communication between the indoor master unit 63 and the entrance slave unit 61 is stopped. Forms a communication path.

[0003] In order to enable the indoor master unit to respond at two locations, there is known a specially-added television intercom apparatus shown in FIG. The TV intercom apparatus includes an entrance slave unit 71, an indoor master unit 72, and an additional indoor master unit 73,
Entrance door station 71 and the indoor base unit 72 is connected by a cable L _6, adding the indoor base unit 72 indoor base unit 73 are connected by a cable L _7. When the call button 4 of the entrance slave unit 71 is pressed, a call signal is detected by the indoor master unit 72. Next, since the detected calling signal is also sent to the additional indoor master unit 73, the ringers of the indoor master unit 72 and the additional indoor master unit 73 ring,
Each television monitor 76, 76 outputs an image. Therefore, for example, when the handset 75 of the indoor master unit 72 is off-hook,
A signal indicating that the handset 75 of the indoor master unit 72 is off-hook is sent to the additional indoor master unit 73, and the television monitor 76 of the additional indoor master unit 73 is turned off. In this state,
A communication path is formed between the indoor master unit 72 and the entrance slave unit 71.

[0004]

In such a TV door phone apparatus in which an indoor master unit is added, the adapter type has a drawback that the wiring must be largely changed because the indoor master unit switching adapter 62 is provided. Also, in the TV door phone apparatus of the dedicated extension type, the indoor master unit for a single station is replaced with an indoor master unit 72 to which the additional indoor master unit 73 can be connected, or the indoor master unit 7 to which the additional indoor master unit 73 can be connected in advance.
2 has to be installed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks, and the construction work of the indoor master unit can be easily performed, and is different from the adapter device for expansion or the indoor master unit for a single station. It is an object of the present invention to provide a TV door phone device which does not require the provision of an additional indoor master unit having a configuration.

[0006]

In order to achieve this object, a television intercom apparatus according to the present invention is provided with an entrance apparatus provided with a camera for imaging a visitor and outputting a video signal, and a television monitor for monitoring the video signal. And a plurality of indoor master units provided with a handset for making a call with the entrance slave unit. Each of the plurality of indoor master units includes an off-hook detection circuit for detecting an off-hook of the handset, and an off-hook detection circuit. A reset signal transmitting circuit for transmitting a reset signal to another indoor master unit in accordance with an operation; and a video signal blocking circuit for blocking a video signal output to a television monitor by the reset signal output from the reset signal transmitting circuit. ing.

[0007]

In this television intercom apparatus, when a handset is off-hook in one indoor master unit in response to a call from the entrance slave unit by a visitor, an off-hook detection circuit operates, and the other indoor master unit is transmitted from the reset signal transmission circuit. Reset signal is sent out. When the off-hook detection circuit of another indoor master unit receives the reset signal, the video signal cutoff circuit operates to cut off the video signal output to the television monitor. Therefore, in one indoor master unit, the video signal from the entrance slave unit can be monitored on the television monitor of the indoor master unit, and the other indoor master unit loses the image.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a preferred embodiment of a television intercom apparatus according to the present invention. 1 and 2, a TV door phone apparatus of the present invention includes a
And a plurality of indoor master units AM and BM connected to the main unit.

The entrance terminal SQ includes a speaker 2, a microphone 3, a call button 4, a camera 5 including a camera eye 1 for imaging a visitor, and a video signal FM modulation circuit 6 for modulating a video signal output from the camera. Is provided. The plurality of indoor master units AM and BM have the same configuration, and each includes a video signal FM demodulation circuit 22 for demodulating a video signal and a television monitor 25 for monitoring the demodulated video signal.

An off-hook detection circuit 33 for detecting the off-hook of the handset is provided to each of the plurality of indoor master units AM and BM.
A reset signal transmission circuit 35 for transmitting a reset signal to another indoor master unit in accordance with the operation of the off-hook detection circuit;
A video signal cutoff circuit 24 for blocking a demodulated video signal output to the television monitor in response to a reset signal output from the reset signal transmission circuit.

[0011] In addition, the terminal T ₂ of the terminal T ₁ and the indoor master unit AM of the entrance door station SQ is connected by a cable L _1, the indoor master unit AM
And BM are connected by a cable L _2. Entrance cordless handset SQ
Includes a camera 5 having a camera eye 1, a video signal FM modulation circuit 6, a multiplexing circuit 10, a microphone 3, a speaker 2, a call button 4, an upstream audio signal AM modulation circuit 7, and a downstream audio signal AM.
Demodulation circuit 8 and the power receiving circuit 9 is provided, the camera 5 is connected to the video signal input of the multiplexing circuit 10 to the terminal T ₁ is connected through a video signal FM modulating circuit 6. Also,
The microphone 3 is connected to the upstream voice signal side of the multiplexing circuit 10 via the upstream voice signal AM modulation circuit 7 to which the call button 4 is connected, and the downstream voice signal side of the multiplexing circuit 10 is the downstream voice signal AM demodulation circuit 8 Through the speaker 2.

The indoor master unit AM has a multiplexing circuit 21, a video signal FM demodulation circuit 22, a video signal output circuit 23 having a built-in sync separation IC 26, a video signal cutoff circuit 24, a television monitor 25, and an upstream audio signal AM demodulation circuit. 27, an upstream audio signal amplifier 28, a downstream audio signal amplifier 29, a downstream audio signal AM modulation circuit 30, a chime sound phase detector 34, a chime sound generation circuit 32, a receiver 31a, a transmitter 31b, and an off-hook detection magnet 31c. Provided handset 31,
Off-hook detection circuit 33 provided with 500 kHz tuning circuit 42, reset signal transmission circuit 35, power supply circuit 36, and C
The video signal side of the multiplexing circuit 21 is connected to a video signal output circuit 23 via a video signal FM demodulation circuit 22.
It is pins P ₁ and the connection pin P ₂ video signal cutoff circuit 24
Via the TV monitor 25. Also,
Pin P ₄ the synchronization signal f ₃ is output, is connected to the pin P ₉ of the reset signal sending circuit 35, the pin P ₃ the lock signal f ₂ is outputted is connected to the control input of the CPU 40.

The upstream audio signal side of the multiplexing circuit 21 is connected to a receiver 31a of a handset 31 via an upstream audio signal AM demodulation circuit 27 and an upstream audio signal amplifier 28,
The transmitter 31b of the handset 31 is connected to the multiplexing circuit 2 via the downstream audio signal amplifier 29 and the downstream audio signal AM modulation circuit 30.
1 downstream audio signal side. The downstream audio signal side of the multiplexing circuit 21 is a chime sound phase detector 34.
Is connected to the control input side of the CPU 40, and the control output side is connected to the receiver 31a of the handset 31 via the chime sound generation circuit 32. Further, the reset signal input side of the multiplexing circuit 21 is connected to the pin P of the off-hook detection circuit 33.
₅ is connected to the pin P ₆ is connected to the control input of the CPU 40. Further, the control output side of the CPU 40 is connected to the pin P ₈ of the reset signal sending circuit 35, and the pin P ₇ is connected to the reset signal sending side of the multiplexing circuit 21.

The control output side of the CPU 40 is connected to the control input side of the video signal cutoff circuit 24 and the power supply circuit 36, and the power supply side of the power supply circuit 36 is connected to the multiplexing circuit 21. The off-hook detection circuit 33, as shown in FIG.
A 500 kHz band pass filter 41 comprising a 500 kHz band pass filter 41, a 500 kHz resonance circuit 42, an amplification circuit 43, a detection circuit 44, and a waveform shaping circuit 45, wherein a pin P ₅ to which a reset signal f ₁ is input is connected to an input side. Is the resistance R of the 500 kHz resonance circuit 42.
It is connected to the reference potential point through a ₁₂ and a capacitor C _3. Further, the other end of the resistor R ₁₁ to a 500kHz signal is connected is connected to the reference potential point via the tuning coil CL _1, the resistor R ₁₁ and the tuning connection point of the coil CL ₁ resistor R ₁₂
It is connected to the connection point of the capacitor C ₃ and. Furthermore, 5
The output side of the 00 kHz band-pass filter 41 has a resistor R ₁₃
And is connected to the base of the transistor Q ₃ of the amplifier circuit 43 via the capacitor C _4, the emitter is connected to one end of a resistor R ₁₆ and capacitor C ₅ connected in parallel. Further, it connected in parallel and the other end of the resistor R ₁₆ and capacitor C ₅ is connected to the reference potential point. The collector is a resistor R ₁₅
Connected to the power source + Vcc through a resistor R ₁₄ is connected between the collector and the base. Then, the collector of the transistor Q ₃ are connected to the cathode of the diode D ₂ via a capacitor C ₆ of the detection circuit 44, the anode is connected to the reference potential point. The cathode of the diode D ₂ is connected to the anode of the diode D _1, the cathode is connected to one end of a resistor R ₁₇ and capacitor C ₇ connected in parallel. The parallel-connected resistor R ₁₇ and the other end of the capacitor C ₇ is connected to the reference potential point.

The transistor Q of the waveform shaping circuit 45
₄ of the base is connected to the other end of the resistor R ₁₈ to the cathode of the diode D ₁ is connected, the emitter is connected to the reference potential point. Further, the collector through a resistor R ₁₉ supply + V
is connected to the cc, the collector and the connection point of the resistor R ₁₉ is pin P
Connected to ₆ . The off-hook detection magnet 31c provided in the handset 31 is connected to a 500 kHz resonance circuit 42.
Hook detection circuit 3 and release from tuning coil CL ₁
3 operates and a control signal is sent to the CPU 40. When the reset signal f ₁ is input from the pin P ₅ , the off-hook detection circuit 33 operates in the same manner, and a control signal is sent to the CPU 40. Reset signal sending circuit 35 is a switch circuit 46 and the buffer circuit 47 as shown in FIG. 4, the other end of the capacitor C ₂ to the pin P ₉ is connected transistors Q
It is connected to the _second base, and an emitter connected to the reference potential point via a resistor R _6. The collector is power supply + Vc
is connected is c, the resistance R ₅ is connected between the collector and the base.

Further, the emitter of the transistor Q ₁ which is provided to the switching circuit 46, the resistor R ₄ is connected, the other end of the resistor R ₄ is connected to the connection point of the emitter of the resistor R ₆ and the transistor Q ₂ I have. Moreover, the base of the transistor Q ₁ is connected to the pin P ₈ through the resistor R _2, the collector is connected to the pin P ₇ via a capacitor C _1. The collector has one end connected to other end of the resistor R ₁ is connected to a reference potential point, the resistor R ₃ is connected between the base and the emitter.

The video signal output circuit 23 incorporates a sync separation IC 26 as shown in FIG. Synchronous separation I
C26 is AFC50, VCO 51, the countdown circuit 52, the lock detection circuit 53, sync separator 54, is constituted by a vertical sync separator 55, the pin P ₁₇ of the sync separation IC26 pin P ₁ of the video signal output circuit 23 is connected Is connected to the input side of the sync separation circuit 54, and the output side is connected to the input side of the vertical sync separation circuit 55 and the AFC 50.
The output side of the vertical synchronization separating circuit 55 is connected to the pin P ₁₅ that outputs VD _OUT, the output side of the count-down circuit 52 is connected to the input side of AFC50 and the lock detection circuit 53. The output side of the lock detection circuit 53 is connected to the pin P ₁₉
And it is connected to the pin P ₄ of the video signal output circuit 23 via the. Further, the output side of the lock detection circuit 53 is connected to the pin P ₃ of the video signal output circuit 23 via a pin P _18. Then, the output side of the lock detection circuit 53 is connected to the pin P ₁₆ for outputting an EXC, the output side of the count-down circuit 52 is connected to the pin P ₁₄ to output the HD _OUT.

The VCO 51 has VCO _IN and VCO _OUT.
Is connected to pin P ₁₃ and pin P ₁₂
The output side of the 50-pin P ₁₁ to output the AFC _CTL is connected. Further, the output side of the AFC 50 is connected to the VCO 51. The pin P ₁ and Pin Pin P ₁ is provided a waveform shaping circuit 23a between P ₂ of the video signal output circuit 23
Waveform of the input video signal is sent to the video signal cutoff circuit 24 via a pin P ₂ is molded from.

In the TV intercom apparatus configured as described above, when the call button 4 of the entrance unit SQ is depressed, the phase of the AM modulation of the upstream audio signal AM modulation circuit 7 is reversed, and the signal passes through the multiplexing circuit 10 through the multiplexing circuit 10. A calling signal is sent to the parent devices AM and BM. In the indoor master units AM and BM, the multiplexing circuit 21 and the chime sound phase detector 34 indicate that there is a call signal, so that the chime sound generation circuit 3 is controlled by the CPU 40.
2 operates to transmit a chime sound to the receiver 31a of the handset 31.

In the indoor master units AM and BM, the power supply circuit 36 operates under the control of the CPU 40, so that an image is output from the television monitor 25. Thus, for example, when the indoor master unit AM goes off-hook, the off-hook detection circuit 33 shown in FIG.
Hz resonance circuit 42 from tuning coil CL ₁ to handset 31
Since leaves, indicating that has been off-hook from the pin P ₆ to CPU 40. Further, since the power supply circuit 36 operates under the control of the CPU 40, an image is output from the television monitor 25. When bounded out from the television monitor 25 lock detection circuit 53 is operated lock signal f ₂ which is provided to the synchronous separation IC26 shown in Figure 5 of the video signal output circuit 23 is sent to the CPU40 through a pin P _3. Next, operate the switch circuit 46 shown in FIG. 4 in the control of the CPU40 because synchronization signal f ₃ is input to the reset signal sending circuit 35 multiplexer circuit 21
To sends a reset signal f _1. Upon receiving the reset signal f ₁ in the off-hook detection circuit 33 of the indoor base unit BM hook detection circuit 33 is operated. Off-hook detection circuit 3
3 operates, the video signal cutoff circuit 2 is controlled by the CPU 40.
4 operates and the path to the television monitor 25 is cut off, and at the same time, the downstream audio signal amplifier 29 does not operate.

In the embodiment described above, the video signal and the audio signal are transmitted after being modulated and demodulated by FM and AM, respectively. In this transmission method, one of the video signal and the audio signal is baseband and the other is FM or AM. The modulation and demodulation method may be used.

[0022]

As is apparent from the above description, according to the television door phone apparatus of the present invention, the installation work of the indoor master unit is easy, and it differs from the adapter apparatus for expansion or the indoor master unit for single station. There is no need to provide an additional indoor master unit having a configuration.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a TV door phone apparatus according to the present invention.

FIG. 2 is a block diagram showing one embodiment of a TV door phone apparatus according to the present invention.

FIG. 3 is a block diagram showing one embodiment of an off-hook detection circuit provided in the TV door phone apparatus according to the present invention;

FIG. 4 is a block diagram showing one embodiment of a reset signal transmission circuit provided in the TV door phone apparatus according to the present invention;

FIG. 5 is a block diagram showing an embodiment of an IC for synchronizing separation provided in the TV door phone apparatus according to the present invention;

FIG. 6 is a configuration diagram of a conventional TV door phone apparatus.

FIG. 7 is a configuration diagram of a conventional TV door phone apparatus.

[Explanation of symbols]

 24 video signal cutoff circuit 25 television monitor 31 handset 33 off-hook detection circuit 35 reset signal transmission circuit SQ: Entrance cordless handset AM, BM: Indoor master unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04M 9/00

Claims (1)

(57) [Claims] 1. A plurality of doors provided with a camera for imaging a visitor and outputting a video signal, a television monitor for monitoring the video signal, and a handset for communicating with the front door. An off-hook detection circuit for detecting an off-hook of the handset, and a reset signal is transmitted to another indoor master unit in accordance with the operation of the off-hook detection circuit. A television intercom apparatus, comprising: a reset signal transmitting circuit that performs a reset signal output from the reset signal transmitting circuit; and a video signal cutoff circuit that blocks a video signal that is output to the television monitor in response to the reset signal output from the reset signal transmitting circuit.