JP3311536B2 - Video switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video splitter for splitting a video signal.

[0002]

2. Description of the Related Art In recent years, a common entrance cordless handset with a camera having a camera and a numeric keypad for inputting a dwelling unit number has been installed at the communal entrance. The number of apartment houses equipped with a system that can unlock the door is increasing. In this system, in order to transmit an image of a visitor of the common entrance to each dwelling unit, it is necessary to install a video splitter or the like on a wiring route to each dwelling unit and transmit a video signal.

Hereinafter, a system using a conventional video splitter will be described with reference to the drawings. FIG. 13 shows a configuration of a conventional video splitter, where 1a and 1b are input terminals for inputting video signals, 2a and 2b are feed terminals for sending a video signal to the next video splitter, and 3 is a video terminal. A terminating circuit for preventing signal reflection, 4 is a terminating switch for switching whether or not to connect the terminating circuit 3, 5 is a video signal amplifying means for amplifying a video signal, and 6 is a power required for the video signal amplifying means 5. The power supply for supplying power, 7a, 7b
Is an output terminal connected to the output. How the video splitter configured as described above is used in an actual apartment house will be described below with reference to FIG.

In FIG. 14, reference numeral 8 denotes a common entrance terminal installed at a common entrance, and reference numeral 9 denotes the above-mentioned conventional video splitter. The video splitter at the last end of each system prevents reflection of a video signal. The terminating switch is turned on in order to Also,
Reference numerals 10a and 10b denote monitor units for displaying images of visitors installed in the dwelling units, and 11a and 11b denote intercoms for talking with visitors at the common entrance, which are installed in the dwelling units a and b, respectively. 12 is a common entrance slave unit 8
A transmission line for transmitting the video signal to the dwelling unit, a transmission line 13 for transmitting a control signal from the common entrance unit 8, and a call signal, and 14a and 14b for instructing the monitor unit to start the video from the intercom. This is the signal line to be given.

The operation of the system configured as described above will be described below. First, it is assumed that the visitor operates the common entrance slave 8 and calls the dwelling unit a. Then
The video signal of the visitor is transmitted to all the dwelling units via the video transmission line 12, and the call signal is transmitted to the intercom 11a of the corresponding dwelling unit a via the transmission line 13. And the intercom 1 receiving this calling signal
1a sounds a ringing tone in the dwelling unit and gives an activation instruction to the monitor unit 10a via the signal line 14a. Then, the monitor unit 10 receiving this instruction
“a” displays the image of the visitor transmitted via the video transmission path 12 and the plurality of video splitters 9 to the monitor.

[0006]

However, in such a video splitter, in order to prevent reflection of the video signal, the terminal switch of the video splitter at the last end of each system is replaced by a switch shown in FIG.
Since it must be turned on as described in 4, the setting must be performed at the time of construction, and there is a problem that a trouble due to a setting error occurs. In addition, since a power supply is required for each video splitter, there is a problem that construction costs for power supply wiring are increased and that a small and inexpensive one cannot be provided. In addition, when a plurality of video splitters are fed and wired, the video signal is attenuated, so that there is a problem that long-distance transmission cannot be supported.

The present invention solves the above-mentioned conventional problems. It is not necessary to set the termination of each system, and it is possible to make the apparatus compact and inexpensive without having a power supply inside the video splitter. It is an object of the present invention to provide a video splitter capable of transmitting a video over a long distance.

[0008]

To achieve the above object, a video splitter according to the present invention comprises an input terminal for inputting a signal, a relay having a common terminal connected to the input terminal, and an NC terminal of the relay. A feed terminal for sending a signal to another video splitter that is connected, an output terminal that is connected to the NO terminal of the relay to output a signal, and a high impedance for the video signal that is connected in parallel to the output terminal And a relay coil connected to an output terminal via the video signal impedance increasing means and driven by a current supplied to the output terminal.

Another video splitter of the present invention sends an input terminal for inputting a signal, a relay having a common terminal connected to the input terminal, and a signal connected to an NC terminal of the relay to another video splitter. A feed terminal, a terminating circuit connected in parallel with the NO terminal of the relay to prevent signal reflection, a video signal amplifying means connected to the input side of the NO terminal of the relay to amplify the video signal, An output terminal connected to the output side of the signal amplifying means for outputting a signal, a video signal impedance increasing means connected in parallel to the output terminal and having a high impedance to the video signal, and a video signal impedance increasing means. And a relay coil for driving a relay that is connected to the output terminal via the output terminal and is driven by a current supplied to the output terminal.

[0010] Still another video splitter according to the present invention includes an input terminal for inputting a signal, a relay having a common terminal connected to the input terminal, and a signal connected to the NC terminal of the relay to send a signal to another video splitter. A sending terminal for sending, a terminating circuit connected in parallel with the NO terminal of the relay to prevent signal reflection, and a video signal amplifying means for amplifying a video signal by connecting the input side to the NO terminal of the relay An output terminal connected to the output side of the video signal amplifying means for outputting a signal; and a low terminal connected in parallel between the input side and the output side of the video signal amplifying means and having a high impedance to the video signal. Frequency transmission means, a video signal impedance-up means connected in parallel to the output terminal and having a high impedance to the video signal, and an output terminal via the video signal impedance-up means It is connected, in which a relay coil for the relay drive driven by a powered current to the output terminal.

Still another video splitter according to the present invention, in addition to the above embodiments, is connected to an arbitrary position between an output terminal and a relay coil to rectify a current supplied to the output terminal. Rectifier means.

Still another video splitter according to the present invention, in addition to the above embodiments, is connected to an arbitrary position between an output terminal and a relay coil to provide an audio signal having a high impedance to the audio signal. Provided with an impedance raising means.

[0013]

With these arrangements, since the video signal is sent via the relay contact, long distance transmission with little attenuation is possible. Further, by outputting the video signal via the video signal amplifying means, further long-distance transmission of the video becomes possible. Further, by supplying a power supply for driving a relay or the like from the outside to the output terminal, it is not necessary to have a power supply inside, and the device can be configured small and inexpensive. Furthermore, by connecting a terminating circuit to the NO terminal side of the relay, there is no need to set a terminating switch at the site where the system is installed.

[0014]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a video splitter according to the present embodiment. In FIG. 1, reference numerals 15a and 15b denote input terminals for inputting signals,
Reference numeral 6 denotes a relay whose common terminal COM is an input terminal 1
5a and 15b. Reference numerals 17a and 17b are connected to the NC terminal of the relay 16 (the NC terminal is a terminal connected to the common terminal COM when no voltage is applied to the relay coil and is abbreviated to normally closed), and other video branches. Terminal for sending a signal to the vessel, 18a,
An output terminal 18b is connected to the NO terminal 18b of the relay 16 (the NO terminal is a terminal connected to the common terminal COM when a voltage is applied to the relay coil and is abbreviated to normally open) and outputs a signal. , 19 are output terminals 18
a and 18b are connected in parallel to each other, and the video signal impedance-up means 20 having a high impedance to the video signal is connected to the video signal impedance-up means 19 and supplied to the output terminals 18a and 18b. This is a relay coil of the relay 16 driven by a DC voltage.

The operation of the video splitter configured as described above will be described. First, when no voltage is applied to the output terminals 18a and 18b, the relay 16 is inactive, and the input terminals 15a and 15b are connected to the feed terminals 17a and 17b via the NC terminal of the relay 16, respectively.
The video signals entering the input terminals 15a and 15b are transmitted to the sending terminals 17a and 17b. Next, when a DC voltage for driving the relay is applied to the output terminals 18a and 18b, the impedance boosting means 19 for a video signal is usually constituted by a small coil. Is applied to
As a result, the relay 16 operates, the contact points fall to the NO terminal side, and the video signals entering the input terminals 15a and 15b are
Output terminals 18a, 18b via NO terminal of relay 16
Will be transmitted. At this time, since the video signal impedance increasing means 19 has a sufficiently high impedance with respect to the high frequency video signal, the video signal is transmitted to the output terminals 18a and 18b without being attenuated.

Next, the operation in the actual system will be described with reference to FIG. In FIG. 2, reference numeral 21 denotes a co-entrance slave unit installed at the co-entrance, 22a, 22b, 22c, 22d,
Reference numerals 22e and 22f denote video splitters, the output terminals of which are connected to the corresponding monitor units of the dwelling units.
The input terminal is connected to the lower side of FIG. However, only two monitor units are described due to space limitations. Reference numerals 23a, 23b and 23c denote video splitters, but the output terminal is connected to the upper side in FIG. 2, the feed terminal is connected to the right side in FIG. 2, and the input terminal is connected to the left side in FIG. 24a,
Reference numeral 24b denotes a monitor unit for displaying an image of a visitor at the common entrance, and reference numerals 25a and 25b denote intercoms for talking with the visitor at the common entrance, which are installed in the dwelling units a and b, respectively. Reference numeral 26 denotes a video transmission line for transmitting the video signal of the common entrance terminal 21 to the dwelling unit; 27, a transmission line for transmitting a control signal and a call signal from the common entrance terminal 21; and 28a, 28b interphones. A signal line for giving a video activation instruction from 25a, 25b to the monitor units 24a, 24b.

The operation of the system configured as described above will be described below. First, the joint entrance slave unit 21
Is operated by the visitor, and the dwelling unit a is called. Then, the control signal for calling is transmitted to the intercom 25a of the corresponding dwelling unit via the transmission path 27. Then, the intercom 25a that has received the calling signal sounds a ringing sound in the dwelling unit and gives an activation instruction to the monitor unit 24a via the signal line 28a. Then, the monitor unit 24a turns on the monitor and applies the DC voltage to the output terminal of the video splitter 22a. The DC voltage activates the relay 16 of the video splitter 22a, and the input terminal is connected to the NO terminal side as shown in FIG.
Then, the DC voltage supplied from the monitor unit 24a passes through the output terminal, NO terminal, and input terminal of 22a,
The signal is applied to the output terminal of the video splitter 23a via the feed terminal, the NC terminal, and the input terminal of the video splitter 22b. As a result, the relay 16 of the video splitter 23a operates, and FIG.
, The input terminal and the output terminal are connected via the NO terminal of the relay 16.

A series of these operations causes the joint entrance slave 2 to operate.
The video signal of No. 1 includes an input terminal of the video splitter 23c, a feed terminal, an input terminal of the video splitter 23b, a feed terminal, an input terminal of the video splitter 23a, an output terminal, an input terminal of the video splitter 22b, a feed terminal, The signal is transmitted to the monitor unit 24a via the input terminal and the output terminal of the video splitter 22a.

As described above, according to the present embodiment, the video signal from the shared entrance terminal 21 is transmitted to the plurality of video splitters 23c.
And so on, only the corresponding dwelling unit is transmitted via the relay contact, so that the attenuation of the video signal is extremely small and long-distance transmission is possible. In addition, if the monitor unit supplies power to up to two video splitters, a video signal path is formed, so that the video splitter does not need to have a power supply, and the device can be made small and inexpensive. In addition, if a termination circuit is provided in the monitor unit, the termination is performed when the video path is formed, and the termination setting in the construction is not required.

(Embodiment 2) FIG. 3 is a block diagram of a video splitter according to a second embodiment of the present invention. In FIG. 3, 15a, 15b, 16, 17a,
17b, 18a, 18b, 19, and 20 are the same as those in the first embodiment, and a description thereof will be omitted. 29
Is a rectifier, which rectifies the DC voltage supplied to the output terminals 18a and 18b, and enables non-polar wiring at the time of construction. Therefore, in addition to the effect of the first embodiment, since the construction can be performed without considering the polarity of the wiring, a unique effect of saving the construction can be obtained.

(Embodiment 3) FIG. 4 is a block diagram of a video splitter according to a third embodiment of the present invention. In FIG. 4, 15a, 15b, 16, 17a,
17b, 18a, 18b, 19, 20, and 29 are the same as those in the above-described second embodiment, and a description thereof will be omitted. Reference numeral 30 denotes an audio signal impedance increasing unit which has a high impedance to an audio signal using a frequency band different from that of the video signal. Therefore, even when the video signal and the audio signal are transmitted while being superimposed on the same line, the absorption of the audio signal by the relay coil 20 is eliminated, and the audio signal and the video signal can be transmitted over a long distance.

(Embodiment 4) FIG. 5 is a block diagram of a video splitter according to a fourth embodiment of the present invention. In FIG. 5, 31a and 31b are input terminals for inputting signals, 32 is a relay, and the common terminal is CO.
M is connected to the input terminals 31a and 31b. 33
Reference numerals a and 33b denote feed terminals connected to the NC terminal of the relay 32 for transmitting a signal to another video splitter;
2, a terminating circuit connected in parallel to the NO terminal of No. 2, a video signal amplifying means 35 connected to the input side of the NO terminal of the relay 32 to amplify the video signal, and 36a and 36b connected to the output side of the video signal amplifying means 35 An output terminal which is connected to output a signal, 37 is connected in parallel to the output terminals 36a and 36b and has a high impedance for video signals having a high impedance to the video signal, and 38 is connected to the impedance up means 37 for video signals Output terminal 36
a, and a relay coil of the relay 32 driven by the DC voltage supplied to 36b.

The operation of the video splitter configured as described above will be described. First, when no DC voltage is applied to the output terminals 36a and 36b, the relay 32 is inactive, and the input terminals 31a and 31b are connected to the NC of the relay 32.
The video signals connected to the feed terminals 33a and 33b via the terminals and entering the input terminals 31a and 31b are
The data is transmitted to the sending terminals 32a and 32b. Next, when a DC voltage is applied to the output terminals 36a and 36b, the video signal amplifying unit 35 obtains a current required for its own operation from the output terminals 36a and 36b, and also increases the video signal impedance up unit 37. Is
Since the DC voltage is usually formed of a small coil, the DC voltage passes through the DC voltage and is applied to the relay coil 38. as a result,
When the relay 32 operates, the contact falls to the NO terminal side, and the video signal that has entered the input terminals 31a and 31b is transmitted to the relay 32.
Are amplified by the video signal amplifying means 35 via the NO terminal of the above, output to the output terminals 36a and 36b, and are automatically terminated by the terminating circuit 34. that time,
Since the video signal impedance increasing means 37 has a sufficiently high impedance with respect to a high frequency video signal, the video signal amplified by the video signal amplifying means 35 is output to the output terminals 36a and 36b without being attenuated. Will be.

Next, the operation in the actual system will be described with reference to FIG. In FIG. 6, 21, 22a, 22b,
22c, 22d, 22e, 22f, 24a, 24b, 2
5a, 25b, 26, 27, 28a, and 28b are the same as those in the first embodiment shown in FIG. 2, and thus description thereof is omitted. Reference numerals 39a, 39b, and 39c denote video splitters according to the present embodiment. The output terminal is connected to the upper side of FIG. 6, the feed terminal is connected to the right side of FIG. 6, and the input terminal is connected to the left side of FIG.

The operation of the system configured as described above will be described below. First, the joint entrance slave unit 21
Is operated by the visitor, and the dwelling unit a is called. Then, the control signal for calling is transmitted to the intercom 25a of the dwelling unit a via the transmission path 27. Then, the intercom 25a that has received the calling signal sounds a ringing sound in the dwelling unit and gives an activation instruction to the monitor unit 24a via the signal line 28a. Then, the monitor unit 24a turns on the monitor and applies the DC voltage to the output terminal of the video splitter 22a. The DC voltage activates the relay 32 of the video splitter 22a, and the input terminal is connected to the NO terminal side as shown in FIG.
Then, the DC voltage supplied from the monitor unit 24a passes through the output terminal, NO terminal, and input terminal of the video splitter 22a, and also passes through the feed terminal, NC terminal, and input terminal of the video splitter 22b. 39a is applied to the output terminal. As a result, the relay 32 of the video splitter 39a operates, is connected to the NO terminal side as shown in FIG. 6, the input terminal and the output terminal are the NO terminal of the relay 32, the video signal amplifying means 3
5 are connected.

By a series of these operations, the video signal of the common entrance terminal 21 is input to the video splitter 39c, the feed terminal, the input terminal of the video splitter 39b, the feed terminal, the input terminal of the video splitter 39a, Video signal amplifying means, output terminal,
Input terminal, feed terminal, video branch 2 of video branch 22b
The signal is transmitted to the monitor unit 24a via the input terminal and output terminal of 2a.

As described above, according to the present embodiment, the video signal from the common entrance terminal 21 is transmitted to the plurality of video splitters 39a.
And so on, and is transmitted to each dwelling unit only via the video signal amplifying means of the video splitter 39a. Transmission becomes possible. In addition, if the monitor unit supplies power to up to two video splitters, a video signal path is formed, so that the video splitter does not need to have a power supply, and the device can be made small and inexpensive. When the video path is formed, the termination circuit 34 connected to the NO terminal side of the relay 32 of the video splitter 39a is automatically inserted into the last end of the horizontal wiring system of the video transmission path, and furthermore, the monitor unit If a terminating circuit is provided inside the vertical wiring system, the vertical wiring system is automatically terminated, and it is not necessary to set a terminating point in construction. For example, when the monitor of the video splitter 22c is turned on, only the relay contacts of the video splitters 22c and 39b fall to the NO side, so that the horizontal wiring system is terminated by the video splitter 39b and the vertical wiring system is terminated. Ends at the video splitter 22
c) in the monitor unit.

(Embodiment 5) FIG. 7 is a block diagram of a video splitter according to a fifth embodiment of the present invention. In FIG. 7, 31a, 31b, 32, 33a,
33b, 34, 36a, 36b, 37, and 38 are the same as those in the above-described fourth embodiment, and a description thereof will be omitted. Reference numeral 40 denotes a rectifier, which rectifies the DC voltage supplied to the output terminals 36a and 36b, and enables nonpolar wiring at the time of construction. Reference numeral 41 denotes a video signal amplifying unit, which operates in the same manner as the video amplifying unit 35 of the fourth embodiment except that power is obtained from the output after rectification of the rectifying unit 40. Therefore, Example 4
In addition to the effects described above, the construction can be performed without considering the polarity of the wiring.

(Embodiment 6) FIG. 8 is a block diagram of a video splitter according to a sixth embodiment of the present invention. In FIG. 8, 31a, 31b, 32, 33a,
33b, 34, 36a, 36b, 37, 38, 40, 4
1 is the same as that of the above-described fifth embodiment, and the description thereof is omitted. Reference numeral 42 denotes an audio signal impedance increasing unit, which has a high impedance for an audio signal using a frequency band different from that of the video signal. Therefore, even when the video signal and the audio signal are superimposed and transmitted on the same line, the absorption of the audio signal by the relay coil is eliminated, and the audio signal and the video signal can be transmitted over a long distance.

(Embodiment 7) FIG. 9 is a block diagram of a video splitter according to a seventh embodiment of the present invention. In FIG. 9, reference numerals 43a and 43b denote input terminals for inputting signals, 44 denotes a relay, and a common terminal COM thereof.
Are connected to the input terminals 43a and 43b. 45a,
45b is a sending terminal connected to the NC terminal of the relay 44 to send a signal to another video splitter, 46 is a termination circuit connected in parallel to the NO terminal of the relay 44, 47 is a relay 4
The video signal amplifying means 48a and 48b are connected to the output side of the video signal amplifying means 47 to output a signal by connecting the input side to the NO terminal 4 and amplifying the video signal.
Reference numeral 9 is connected in parallel to the output terminals 48a and 48b, and a video signal impedance increasing means having a high impedance to the video signal, and 50 is connected to the video signal impedance increasing means 49 and output terminals 48a and 48b.
The relay coil 51 of the relay 44, which is driven by the voltage supplied to the terminal b, is connected in parallel between the input side and the output side of the video signal amplifying means 47, and has output terminals 48a, 48b.
This is a low-frequency transmission unit that supplies the DC voltage supplied to the NO terminal to the NO terminal of the relay 44 and has a high impedance with respect to a high-frequency video signal.

The operation of the video splitter configured as described above will be described below. First, the output terminals 48a, 4
When the voltage is not applied to the relay 8b, the relay 44 is inoperative, and the input terminals 43a, 43b are connected to the feed terminals 45a, 45b via the NC terminal of the relay 44, respectively, and enter the input terminals 43a, 43b. The received video signal is transmitted to the sending terminals 45a and 45b. Next, when a DC voltage is applied to the output terminals 48a and 48b, the video signal amplifying means 47 obtains a current required for its own operation from the output terminals 48a and 48b, and a video signal impedance increasing means 49.
Is usually formed of a small coil, so that the DC voltage is applied to the relay coil 50 through this. As a result, the relay 44 operates, the contact falls down to the NO terminal side, and the video signal that has entered the input terminals 43a and 43b is amplified by the video signal amplifying means 47 via the NO terminal of the relay 44, and the output terminal 48a , 48b, and is automatically terminated by the termination circuit 46. At this time, since the video signal impedance increasing means 49 has a sufficiently high impedance with respect to the high frequency video signal, the video signal amplified by the video signal amplifying means 47 is output to the output terminals 48a and 48b without being attenuated. Will be output. The DC voltage applied to the output terminals 48a and 48b is transmitted to the low-frequency
No. 4 is sent to the input terminals 43a and 43b via the NO terminal.

Next, the operation in the actual system will be described with reference to FIG. In FIG. 10, 21, 22a, 22
b, 22c, 22d, 22e, 22f, 24a, 24
b, 25a, 25b, 26, 27, 28a, 28b
The description is omitted because it is the same as that of the first embodiment shown in FIG. 52a, 52b, 52c, 52d, 52
Reference numerals e, 52f, 52g, and 52h denote video splitters according to the present embodiment. The output terminal is connected to the upper side of FIG. 10, the feed terminal is connected to the right side, and the input terminal is connected to the left side.

The operation of the system configured as described above will be described below. First, the joint entrance slave unit 21
Is operated by the visitor, and the dwelling unit a is called. Then, the control signal for calling is transmitted to the intercom 25a of the dwelling unit a via the transmission path 27. Then, the intercom 25a that has received the calling signal sounds a ringing sound in the dwelling unit and gives an activation instruction to the monitor unit 24a via the signal line 28a. Then, the monitor unit 24a turns on the monitor and applies the DC voltage to the output terminal of the video splitter 22a. This DC voltage activates the relay 44 of the video splitter 22a, and the input terminal is connected to the NO terminal side as shown in FIG. Then, the DC voltage supplied from the monitor unit 24a passes through the output terminal, NO terminal, and input terminal of the video splitter 22a, and also passes through the feed terminal, NC terminal, and input terminal of the video splitter 22b. The signal is applied to the output terminal of the branching device 52a. As a result, the relay 44 of the video splitter 52a operates and is connected to the NO terminal side as shown in FIG.
The input terminal and the output terminal are connected via the video signal amplifier 47. The DC voltage supplied from the monitor unit 24a is also transmitted to the input terminal of the video splitter 52a by the operation of the low frequency transmission means 51, and the feed terminal and input terminal of the video splitter 52b and the feed terminal of the video splitter 52c are transmitted. Are applied to the output terminal of the video splitter 52d via the input terminal. Thereby, the relay 4 of the video splitter 52d is
4 operates and is connected to the NO terminal side as shown in FIG. 10, and the input terminal and the output terminal are connected via the video signal amplifying means 47.

By a series of these operations, the video signal of the common entrance terminal 21 is input to the video splitter 52d, the video signal amplifying means, the output terminal, the input terminal of the video splitter 52c, the feed terminal, the video splitter. 52b input terminal, feed terminal, input terminal of video splitter 52a, video signal amplifying means,
The data is transmitted to the monitor unit 24a via the output terminal, the input terminal of the video splitter 22b, the feed terminal, the input terminal of the video splitter 22a, and the output terminal.

As described above, according to the present embodiment, the video signal from the shared entrance terminal 21 is transmitted to the plurality of video splitters 52a.
And the like, are transmitted only to the corresponding dwelling unit via the relay contact, and transmitted to each dwelling unit via the two-stage video signal amplifying means in the video splitters 52a and 52d. Amplification is performed in two stages, and further long-distance transmission becomes possible. In addition, video splitter 52
By adding a video splitter to the feed terminal of h, the number of systems can be easily increased, and video signals can be transmitted to more dwelling units. Furthermore, if the monitor unit supplies power to up to three video splitters 22a, 52a, and 52d, a video signal path is formed, so that the video splitter does not need to have a power source, and the apparatus is small and inexpensive. Can be configured. When the video path is formed, the video splitter 5
If the termination circuit 46 connected to the NO terminal side of the relay 44 of 2a and 52d is automatically inserted into the two horizontal wiring systems of the video transmission line, and if the termination circuit is provided in the monitor unit, the vertical wiring The system is automatically terminated, so that there is no need to set the termination in the construction.

(Embodiment 8) FIG. 11 is a block diagram of a video splitter according to an eighth embodiment of the present invention. In FIG. 11, 43a, 43b, 44, 45
a, 45b, 46, 48a, 48b, 49, 50, 51
Are the same as those in the above-described seventh embodiment, and thus description thereof will be omitted. Reference numeral 53 denotes a rectifier, and output terminals 48a,
The DC voltage supplied to 48b is rectified to enable non-polar wiring during construction. Reference numeral 54 denotes a video signal amplifying unit, which operates in the same manner as the video signal amplifying unit 47 of the seventh embodiment, except that power is obtained from the rectified output of the rectifying unit 53. Therefore, in addition to the effect of the seventh embodiment, since the construction can be performed without considering the polarity of the wiring, a unique effect of saving the construction can be obtained.

(Embodiment 9) FIG. 12 is a block diagram of a video splitter according to a ninth embodiment of the present invention. In FIG. 12, 43a, 43b, 44, 45
a, 45b, 46, 48a, 48b, 49, 50, 5
1 and 53 are the same as those in the above-described eighth embodiment, and thus description thereof will be omitted. Reference numeral 54 denotes an audio signal impedance increasing unit, which has a high impedance with respect to an audio signal using a frequency band different from that of a video signal. Therefore, even when the video signal and the audio signal are transmitted while being superimposed on the same line, the absorption of the audio signal by the relay coil 50 is eliminated, and the audio signal and the video signal can be transmitted over a long distance. Further, since the low-frequency transmitting means 51 has a low impedance with respect to a low frequency, if a low frequency is used as an audio signal, the output terminals 48a and 48a are used even when the video signal amplifying means 53 does not amplify the audio signal.
The audio signal is transmitted to b.

Examples 2, 3, 5, 6, 8, 9, 1
1 and 12, the positional relationship between the rectifier and the video signal impedance-up unit, or the rectifier, the audio signal impedance-up unit, and the video signal impedance-up unit may be interchanged with each other. May amplify the audio signal.

[0039]

As described above, according to the present invention, as is apparent from the above embodiments, since the video signal is transmitted via the relay contacts, long-distance transmission with little attenuation is possible. . Further, by outputting the video signal via the video signal amplifying means, further long-distance transmission of the video becomes possible. Further, by supplying power to the output terminal from the monitor unit of the dwelling unit for driving the relay and the video signal amplifying means, it is not necessary to have a power supply inside, and the device can be made compact and inexpensive. Furthermore, by connecting a terminating circuit to the inside of the monitor unit or to the NO terminal side of the relay in the case of having a video signal amplifying means, it is not necessary to set a terminating switch on site, and the effect is greatly enhanced. There is something.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video splitter according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a system according to the first embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a video splitter according to a second embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a video splitter according to a third embodiment of the present invention.

FIG. 5 is a block diagram illustrating a configuration of a video splitter according to a fourth embodiment of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a system according to a fourth embodiment of the present invention.

FIG. 7 is a block diagram illustrating a configuration of a video splitter according to a fifth embodiment of the present invention.

FIG. 8 is a block diagram illustrating a configuration of a video splitter according to a sixth embodiment of the present invention.

FIG. 9 is a block diagram illustrating a configuration of a video splitter according to a seventh embodiment of the present invention.

FIG. 10 is a block diagram illustrating a system configuration according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram illustrating a configuration of a video splitter according to an eighth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a configuration of a video splitter according to a ninth embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a conventional video splitter.

FIG. 14 is a block diagram showing a configuration of a system using a conventional video splitter.

[Explanation of symbols]

 15a, 15b Input terminal 16 Relay 17a, 17b Send terminal 18a, 18b Output terminal 19 Impedance increasing means for video signal 20 Relay coil 21 Shared entrance terminal 22a to 22f Video splitter 23a to 23c Video splitter 24a, 24b Monitor unit 25a , 25b Interphone 26 Video transmission path 27 Transmission path 28a, 28b Signal line 29 Rectifying means 30 Impedance up means for audio signal 31a, 31b Input terminal 32 Relay 33a, 33b Send terminal 34 Termination circuit 35 Video signal amplifying means 36a, 36b Output terminal 37 Impedance Up Means for Video Signals 38 Relay Coil 39a to 39c Video Divider 40 Rectification Means 41 Video Signal Amplification Means 42 Impedance Up Means for Audio Signals 43a, 43b Input Terminals 44 -45a, 45b Send terminal 46 Termination circuit 47 Video signal amplifying means 48a, 48b Output terminal 49 Video signal impedance up means 50 Relay coil 51 Low frequency transmission means 52a to 52h Video splitter 53 Video signal amplifying means 54 Audio signal impedance Up means

Continuation of the front page (56) References JP-A-3-292086 (JP, A) JP-A-3-83475 (JP, A) JP-A-3-83443 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H04N 7/18 H04M 9/00 H04N 5/268

Claims (9)

(57) [Claims] An input terminal for inputting a signal; a relay having a common terminal connected to the input terminal;
A feed terminal connected to the C terminal for sending a signal to another video splitter; an output terminal connected to the NO terminal of the relay for outputting a signal; and a output terminal connected in parallel to the output terminal to generate a video signal. A video signal impedance-up unit having a high impedance to the output terminal, and the relay driving relay connected to the output terminal via the video signal impedance-up unit and driven by a current supplied to the output terminal. Video splitter with coil. 2. The video splitter according to claim 1, further comprising a rectifier connected to an arbitrary position between the output terminal and the relay coil for rectifying a current supplied to the output terminal. 3. The video splitter according to claim 2, further comprising an audio signal impedance-up means connected to an arbitrary position between the output terminal and the relay coil and having a high impedance to the audio signal. 4. An input terminal for inputting a signal, a relay having a common terminal connected to the input terminal, and an N of the relay.
A sending terminal connected to the C terminal for sending a signal to another video splitter; a terminating circuit connected in parallel to the NO terminal of the relay to prevent signal reflection;
A video signal amplifying means connected to the input side to amplify the video signal; an output terminal connected to the output side of the video signal amplifying means for outputting a signal; and a video signal connected in parallel to the output terminal. A video signal impedance-up means having a high impedance to the relay drive, which is connected to the output terminal via the video signal impedance-up means and is driven by a current supplied to the output terminal. Video splitter with relay coil. 5. The video splitter according to claim 4, further comprising a rectifier connected to an arbitrary position between the output terminal and the relay coil for rectifying a current supplied to the output terminal. 6. The video splitter according to claim 5, further comprising an audio signal impedance increasing means connected to an arbitrary position between the output terminal and the relay coil and having a high impedance to the audio signal. 7. An input terminal for inputting a signal, a relay having a common terminal connected to the input terminal, and an N of the relay.
A sending terminal connected to the C terminal for sending a signal to another video splitter; a terminating circuit connected in parallel to the NO terminal of the relay to prevent signal reflection;
A video signal amplifying means connected to an input side to a terminal for amplifying a video signal; an output terminal connected to an output side of the video signal amplifying means for outputting a signal; and an input side of the video signal amplifying means. A low-frequency transmitting means connected in parallel with the output side and having a high impedance to the video signal; and a video signal impedance-up means connected in parallel to the output terminal and having a high impedance to the video signal. And a relay coil connected to the output terminal via the video signal impedance increasing means and driven by a current supplied to the output terminal. 8. The video splitter according to claim 7, further comprising a rectifier connected to an arbitrary position between the output terminal and the relay coil for rectifying a current supplied to the output terminal. 9. The video splitter according to claim 8, further comprising an audio signal impedance increasing means connected to an arbitrary position between the output terminal and the relay coil and having a high impedance to the audio signal.