JPH08181979A - Video doorphone device - Google Patents

Abstract

PURPOSE: To suppress deterioration by aging in image quality by increasing an amplification factor for a video signal based on a noise level between a monitor camera and a terminal. CONSTITUTION: Plural terminals H are interconnected by a multi-pair balanced cable including a video transmission line Ma from a monitor camera A, a speech transmission line Mb from a lobby interphone B and a control transmission line Mc propagating data for control. The lobby interphone B and a selected terminal H are communicated and a caller is monitored by the terminal H with a video signal sent from the monitor camera A and the monitor camera A is provided with a reference video signal output section A, providing an output of a reference video signal in the case of no communication. Then the terminal H is provided with a noise level detection section Gg detecting a level of noise included in the received reference video signal and a video signal amplifier section Cf increasing the amplification factor is provided between the monitor camera A and the terminal H to increase the amplification factor when the noise level exceeds a prescribed level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door intercom device which is connected by wiring using a multi-pair balanced cable.

[0002]

2. Description of the Related Art In recent years, in an apartment house or the like, a visitor can call a dwelling unit terminal at a visited place from a lobby intercom installed in a lobby at the entrance and make a call to the dweller at the visited place. A door intercom device is used by a calling resident, who is a caller, to make a call while monitoring the imaged image of the visitor from a monitor camera installed in the lobby at a dwelling unit terminal. FIG. 2 is a block diagram showing a conventional TV intercom device as described above, and FIG. 3 is a block diagram showing another TV intercom device as described above.

In FIG. 2, A is a monitor camera, B is a lobby intercom, C is a video control panel, D is a monitoring panel, and E,
Each of ... is a turnout device, each of F, ... is a dwelling unit intercom, and each of G ,. Further, each of H, ... Is a dwelling unit terminal, and one dwelling unit terminal H is configured to include a dwelling unit intercom F and a monitor television G.

The monitor camera A is used for the entrance of an apartment house or the like.
It is installed in the lobby and emits video signals from visitors.
Image pickup unit A_aAnd video FM modulator A_bAnd amplification
Bowl A _cAnd output circuit A_dAnd a power supply that supplies power to each
Circuit A_eIt is configured to include and. Imaging unit A_aIs the subject
The body is imaged and a video signal is output. Video FM modulator A _b
Is the imaging unit A_aFrequency-modulates the video signal output by. Increase
Width A_cAmplifies the frequency-modulated video signal and outputs
Road A_dOutput to. Output circuit A_dIs frequency modulated
Image signal to a pair of twisted pair cable L_0aOutput to.

The lobby intercom B is installed in an entrance lobby of an apartment house or the like, and is operated by a visitor to call a dwelling unit of a visited place and call the dweller of the dwelling unit. The microphone B _a , the speaker B _b and the voice are used. Transmission / reception circuit B _c , key operation unit B _d , input / output interface _Be, and control circuit B _f
And a power supply circuit B _g for supplying power to each. The microphone B _a picks up the voice of the visitor. The speaker B _b outputs the voice of the resident of the called dwelling unit in each dwelling unit. The voice transmission / reception circuit B _c has two lines
A pair of twisted pair cables for a two-way call between a visitor and a called party (resident of the dwelling unit called by the visitor), which is composed of a 4-wire conversion circuit (not shown) and an amplifier (not shown). It is possible with L _0b . The key operation unit B _d is a part where the visitor inputs the visited unit number. The input / output interface _Be is an interface between the key operation unit _Bd and the control circuit _Bf . The control circuit B _f is connected to the pair of twisted pair cables L _0c , and controls the on / off control of the power supply circuit A _e of the monitor camera A and the call control of each dwelling unit.

The image control board C is installed in a manager's room or the like, and has an input circuit C _a , an amplifier C _b, and a voltage superposition circuit C _c.
And output circuit C _d and power supply circuit C for supplying power to each
It is configured to include _e and. The input circuit C _a receives the video signal output from the output circuit A _d and outputs it to the amplifier C _b . The voltage superposition circuit C _c superimposes the DC voltage output from the power supply circuit C _{e on} the video signal output from the amplifier C _b . The output circuit C _d outputs the video signal on which the DC voltage is superimposed to the pair of twisted pair cables L _0a .

When the monitoring board D is installed in a manager's room, etc.
Both are used by the administrator, and the handset D_aAnd voice transmission
Receiver circuit D_bAnd key operation part D_cAnd input / output interface
Space D _dAnd control circuit D_eAnd a power supply that supplies power to each
Circuit D_fIt is configured to include and. Handset D_aIs
What is used when the manager calls the resident of each dwelling unit
It has a microphone and a speaker. Voice transmission / reception circuit
D_bIs a 2-wire / 4-wire conversion circuit (not shown) and an amplifier (Fig.
(Not shown) and the manager and the called party (call the manager
Two-way call with the resident of the dwelling unit).
Ist pair cable L_0bIt is possible in. Key operation
Part D_cIs the unit number of the unit the manager wants to call.
Is the part to enter. Input / output interface D
_dIs the key operation part D_cAnd control circuit D_eInter between
It is a face. Control circuit D_eIs one twisted pair
Cable L_0cConnected to the lobby intercom B control
Circuit B _fAnd the control circuit F of the housing unit H, ..._eControl of…
In addition to controlling the call control of each dwelling unit.

The branch devices E, ... Are twisted pair cables L.
_0a, L _0b, L _0c are respectively branched and drawn into each dwelling unit and are sequentially fed and wired, and the branching device E is a branch for drawing in the dwelling unit terminal H and a feeding wire to the next branching device E. Is possible. The branching device E is configured as follows. That is, the branching device E includes the video signal input terminal E _a , the control signal input terminal E _b , the audio signal input terminal E _c , the video signal output terminal E _d , the control signal output terminal E _e , the audio signal output terminal E _f, and the video signal. It is configured to include a branch output terminal E _g , a control branch output terminal E _h , an audio branch output terminal E _i, and a video branch circuit E _j . The video branch circuit E _j is composed of a transformer. In addition, twisted pair cable L
_{In 0a,} L _0b, L _0c , a multi-pair twisted pair cable L ₀ having at least 3 pairs of twisted pair cables is used.

The dwelling unit intercoms F, ... are living rooms of each dwelling unit.
One is installed in each of such as
Is configured. That is, the dwelling unit intercom F
Handset F_aAnd voice transmission / reception circuit F_bAnd key operation part F_cWhen
Input / output interface F_dAnd control circuit F_eAnd each
Circuit F for supplying power to_fConsists of and
It Handset F_aResidents call visitors and admins
Used in the case, equipped with microphone and speaker
There is. Voice transmission / reception circuit F_bIs a 2-wire / 4-wire conversion circuit (Fig.
It consists of an amplifier (not shown) and an amplifier (not shown).
And two-way call with the manager
Bull L_0bIt is possible in. Key operation part F_cIs the residence
Enter the housing unit number or manager's room number that the person wants to call.
It is the part that applies. Input / output interface F_dIs
-Operation part F_cAnd control circuit F_eInterface to and from
Is. Control circuit F_eIs a pair of twisted pair cables
L _0cConnected to the control circuit D_eExchange control signals with
Input circuit G of monitor TV G_aIs controlling
It

The monitor televisions G, ... Are installed one by one in the living room of each dwelling unit, etc., and are usually installed together with the dwelling unit intercom H, and are configured as follows. That is, the monitor television G is configured to include an input circuit G _a , a voltage separation circuit G _b , an amplifier G _c , a video FM demodulation unit G _d , a display unit G _e, and a power supply circuit G _f that supplies power to each. ing. The input circuit G _a receives the video signal output from the output circuit C _d of the video control board C and outputs it to the voltage separation circuit G _b . The voltage separation circuit G _b separates the DC voltage superimposed on the video signal by the voltage superposition circuit C _{c and} outputs the DC voltage to the power supply circuit G _f , and removes the superimposed DC voltage from the video signal. Output to the amplifier G _c . The amplifier G _c amplifies the video signal and outputs it to the video FM demodulation unit G _d . Video FM demodulator G _d is output to the display unit G _e demodulates the video signal that has been frequency modulated, the display unit G _e is mirror the captured image of the monitor camera A.

Therefore, in the TV door intercom apparatus configured as described above, the resident can talk while seeing the appearance of the visitor who has visited the entrance lobby of the apartment complex, which is convenient and safe. There is also an effect.

The TV door intercom device shown in FIG. 3 is substantially the same as the TV door intercom device shown in FIG. 2, and the same parts are designated by the same reference numerals, and a detailed description thereof will be omitted. The difference is the following configuration. That is, FIG.
In the TV intercom device of No. 1, a pair of twisted pair cables L _0a are used as video signal transmission lines, a pair of twisted pair cables L _0b are used as audio signal transmission lines, and a pair of twisted pair cables are used as control signal transmission lines. It is specified to use L _0c respectively, and a multi-pair twisted pair cable L ₀ was used. However, in the TV intercom apparatus of FIG. 3, the audio signal transmission line is 1
A pair of twisted pair cables L _0b is used as a control signal transmission line, and a pair of twisted pair cables L _0c is used as a control signal transmission line, but a coaxial cable L ₁ is used as a video signal transmission line. is there.

[0013]

By the way, the conventional TV door intercom apparatus as described above is expensive in order to prevent the deterioration of the image quality of the video image displayed on the display unit G _e of the monitor TV G. Since the coaxial cable or the expensive twisted pair cable is used, the construction cost is high and the wiring process is complicated. However, in order to facilitate the wiring process and reduce the construction cost, using a multi-pair balanced cable, which is an inexpensive multi-pair signal line, causes a gap between adjacent signal line pairs compared to a coaxial cable or twisted pair cable. Since the noise resistance of the video signal is inferior, the connection terminal screw at the connection part of the video signal line loosens or oxidizes after a long period of construction, and the level of the modulated video signal propagating decreases. The ratio of noise components from other lines or from external sources
There is a problem that noise appears in the image displayed on the monitor TV.

The present invention has been made in order to solve the above problems, and an object of the present invention is to prevent deterioration of image quality due to aging even if a multi-pair balanced cable is used. It is to provide an excellent TV intercom device that can be operated without any operation.

[0015]

In order to solve the above-mentioned problems, the present invention provides a video transmission path from a monitor camera, a call transmission path from a lobby intercom, and control. A plurality of dwelling unit terminals are connected to a multi-pair balanced cable including a control transmission line for propagating controlled data, and a call is made between the lobby intercom and the selected dwelling unit terminal and transmitted from the monitor camera. In the TV intercom device capable of monitoring the caller at the dwelling unit terminal by the video signal, the monitor camera is provided with a reference video signal output unit for outputting a reference video signal when no call is made, The dwell unit terminal is provided with a noise level detection unit for detecting a noise level included in the received reference video signal, and the monitor camera or the monitor Between camera and said dwelling terminal, wherein the noise level is provided a video signal amplifier which operates to increase the amplification factor exceeds a predetermined value.

According to the second aspect of the invention, there is provided a noise level excess notifying unit for notifying that the noise level exceeds the predetermined value when the noise level exceeds the predetermined value.

[0017]

With the above arrangement, the monitor camera outputs the reference video signal from the reference video signal output section when no call is being made. When the dwelling unit terminal receives the reference video signal,
The signal-to-noise ratio (hereinafter referred to as S / N) included in the reference video signal.
Ratio) is detected and whether the S / N ratio is less than or equal to a predetermined value is determined, and if the S / N ratio is less than or equal to the predetermined value, the fact is notified to the video signal amplification unit. Upon receiving the notification that the S / N ratio is equal to or less than the predetermined value, the video signal amplification unit increases the amplification factor and increases the level of the video signal sent to the video transmission path. Therefore, the S / N ratio is improved even if the level of the video signal input to the dwelling unit terminal decreases due to deterioration over time and the S / N ratio of the video signal relatively decreases. Therefore, even if a multi-pair balanced cable is used, deterioration of image quality over time can be suppressed, and operation can be performed without any trouble.

According to the second aspect of the present invention, the monitor camera outputs the reference video signal from the reference video signal output section when no call is being made. When the dwelling unit terminal receives the reference video signal, the S / S included in the reference video signal
The N ratio is detected and it is determined whether or not the S / N ratio is less than or equal to a predetermined value. If the S / N ratio is less than or equal to the predetermined value, the fact is notified to the video signal amplification unit and the noise level excess notification unit. To notify. The noise level excess notification unit, which has received the notification that the S / N ratio is less than or equal to the predetermined value, notifies that maintenance is necessary because the attenuation of the video signal in the video transmission line is increasing. Prompt for inspection. Also, S / N
Upon receiving the notification that the ratio is less than or equal to the predetermined value, the video signal amplification unit increases the amplification factor and enhances the level of the video signal sent to the video transmission path to prevent image quality deterioration during maintenance and inspection. To do. Therefore, maintenance and inspection can be performed at an appropriate time, and even if a multi-pair balanced cable is used, deterioration of image quality over time can be suppressed, and operation can be performed without any trouble.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a TV intercom system according to the present invention will be described in detail below with reference to FIG. Note that, in FIG. 1, the same parts as those of the conventional TV intercom apparatus described with reference to FIG. 2 or FIG. Detailed description of equivalent parts will be omitted.

This television intercom device is different from the conventional one in that it has the following features. That is, as shown in FIG. 1, the monitor camera A is connected to the reference video signal output unit A _f.
A control circuit C _f for increasing the amplification factor of an amplifier C _b corresponding to a video signal amplification unit is provided on the video control panel C, a noise level excess notification unit D _g is provided on the monitoring panel D, and a monitor television G is provided. A noise level detection unit G _g and a noise level excess transmission unit G _h are provided, and instead of the conventional twisted pair cable or coaxial cable, a video signal line Ma corresponding to a video transmission line and a call corresponding to _a call transmission line are provided. A multi-pair balanced cable M, which is a multi-core cable including a signal line M _b and a control signal line M _c corresponding to a control transmission line, and which is not twisted pair is used.

The reference video signal output unit A _f is a reference video signal (white peak 100) which serves as a reference when the noise level detection unit G _g detects the noise level included in the video signal.
% Signal etc.) based on an instruction from the control circuit B _f to the video FM demodulation unit A _b . The control circuit C _f is connected to the control signal line M _c so as to exchange a control signal with the control circuit _De and to control the amplification factor of the amplifier C _b . Noise level excess notification unit D
_g, based on an instruction from the control circuit D _e via the output interface D _d, and is to perform a notification indication maintenance is required.

The noise level detector G _g is an S of the demodulated reference video signal output from the video FM demodulator G _d.
The A / N ratio is detected, and it is determined whether the S / N ratio is less than or equal to a predetermined value. If the S / N ratio is less than or equal to a predetermined value, the noise level excess transmission unit G _h is notified of that fact. It is supposed to do. The noise level excess transmission unit G _h is used for the video FM.
When the noise level detection unit G _g receives a notification that the S / N ratio of the reference video signal output from the demodulation unit G _d is equal to or less than a predetermined value, the control circuit F _e is notified of that fact. .

A TV door phone device having the above-described structure
In the table, it works as follows and
Operated. That is, the control circuit D_eIs the lobby interface
-If there is no call between phone B and dwell unit H
Control circuit B _fAgainst the reference video signal
Output part A_fTo standard video signal (white peak 100%
Signal etc.) Video FM demodulation unit A_bInstruct to output to
I do.

[0024] Then, the control circuit B _f gives an instruction to the reference video signal output unit A _f, the reference video signal from the reference video signal output unit A _f (such as white peak 100% signal) to the video FM modulation section A _b To output. The video FM modulator A _b , to which the reference video signal is input, frequency-modulates the reference video signal and outputs it to the amplifier A _c . The amplifier A _c amplifies the frequency-modulated reference video signal and outputs it to the output circuit A _d . Output circuit A _d outputs a reference video signal that is frequency-modulated to the video signal line M _a.

The reference video signal is frequency modulated and output to the video signal line M _a is propagated through the video signal line M _a is input to the input circuit C _a video control panel C, the amplifier from the input circuit C _a It is output to C _b . Then, as in the case of normal video signal, the frequency-modulated reference video signal is amplified by the amplifier C _b, a DC voltage is superimposed by the voltage superimposing circuit C _c, the video signal line M by the output circuit C _d It is sent to the monitor television G via _a and the branching device E.

The frequency-modulated reference video signal output from the output circuit C _d is received by the input circuit G _a of the monitor television G and output to the voltage separation circuit G _b . Voltage isolation circuit G _b, the power supply circuit to said DC voltage by separating the DC voltage superimposed on the reference image signal by the voltage superimposing circuit C _c G _f
And the reference video signal from which the superimposed DC voltage is removed is output to the amplifier G _c . Amplifier G _c
Amplifies the reference video signal and outputs it to the video FM demodulation unit G _d . The video FM demodulation unit G _d demodulates the frequency-modulated reference video signal and outputs it to the noise level detection unit G _g . The noise level detection unit G _g detects the signal level and the noise level from the demodulated reference video signal output from the video FM demodulation unit G _d , and obtains the S / N ratio which is the ratio of the respective levels, If the S / N ratio is less than or equal to the predetermined value (that is, if the ratio of the noise component is high), the fact is notified to the noise level excess transfer unit G _h .

The noise level exceeded transmitting unit G _h is notified that the S / N ratio from the noise level detecting unit G _g receives the notification is below a predetermined value to the control circuit F _e, the control circuit F _e noise The control circuit _De is notified via the control signal line M _c that the S / N ratio is below the predetermined value from the level excess transmission unit G _h . Then, the control circuit D _e operates the noise level exceeds the alert section D _g through the input-output interface D _d, indicating that there is a need for maintenance because the attenuation of the video signal has become larger in the video signal line M _a Is displayed to prompt maintenance and inspection, and the control circuit C _f is instructed via the control signal line M _c to increase the amplification factor of the amplifier C _b and maintain the high amplification factor. Then, the amplifier C _b is the input circuit becomes an C _a output video signal of such amplifies and outputs the above so far, the video signal arriving via the splitter E video signal line M _a to monitor television G Becomes higher, the ratio of noise components from other lines transferred to the video signal or from outside is relatively reduced, and the display unit G _e of the monitor TV G can display a clear image without noise. .

The display unit G _e has a control circuit F _e.
Thus, while a call is being made between the lobby intercom B and the dwelling unit terminal H, the image of the visitor is displayed based on the image signal sent from the monitor camera A, but the lobby intercom B and the dwelling unit terminal H are displayed. It is controlled so that it does not operate when there is no call between them.

[0029] That is, in the period shortly after the start of the operation, the connection terminal screws of the connecting portion of the video signal line is not or oxidation loose, modulated propagating video signal line M _a The level of the video signal is equal to or higher than a predetermined value and does not decrease, and the ratio of noise components from another line transferred to the video signal or from outside is kept at a predetermined value or lower.
Therefore, the amplification factor of the amplifier C _b is maintained at a normal level at a time immediately after the start of operation, and
The noise level excess notifying unit D _g also makes no notification.

However, for a long time after starting operation
The video signal line M _aConnection of the connection part
If the terminal screw loosens or oxidizes, the video signal line M_aTell
The level of the modulated video signal to be carried falls and the video signal
Ratio of noise components from other lines or from external lines
Noise increases in the image displayed on the monitor TV.
When it comes to a state where
Chibe D_gTo activate the video signal line M_aOf the video signal in
As the attenuation is increasing, maintenance is required.
Prompt the manager to perform maintenance inspection by displaying a message to that effect.
At the same time, prevent deterioration of image quality before maintenance and inspection.
Amplifier C_bThe amplification factor of is set high.

[0031] The present invention is not limited to the above embodiments, in the above-mentioned TV door device, the control circuit D _e is not performed the call with lobby interphone B and dwelling terminal H If it is time, the S / N ratio is detected at any time and the noise level excess notification unit D
_{Although the g} is operated and the amplification factor of the amplifier C _b is increased, only during the set time during the time when no communication is performed between the lobby intercom B and the dwell unit terminal H. It is also possible to detect the S / N ratio and operate the noise level excess notifying unit D _g or set the amplification factor of the amplifier C _b by increasing it.

[0032]

Since the television door intercom apparatus of the present invention is configured as described above, the invention according to claim 1 uses a multi-pair balanced cable which is easy to wire and is inexpensive. However, deterioration of image quality over time can be suppressed, and in the invention of claim 2, in addition to the above effect, the image signal is further attenuated due to deterioration over time, so that maintenance is required. It is possible to notify that it is the time for maintenance and inspection, and it is possible to prevent image quality deterioration before maintenance and inspection, and operation comparable to that when using coaxial cable or twisted pair cable. The effect that it is possible to provide an excellent TV intercom device is possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a TV door intercom apparatus according to the present invention.

FIG. 2 is a block diagram showing a conventional TV intercom device.

FIG. 3 is a block diagram showing another example of a conventional TV door intercom apparatus.

[Explanation of symbols]

A monitor camera A _f reference video signal output section B lobby interphone C _f video signal amplifier D _g noise level exceeds the alert section G _g noise level detection unit H dwelling terminal M many-balanced cable M _a video transmission path M _b call transmission path M _c control transmission line

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[Procedure amendment]

[Submission date] February 3, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

The reference video signal output unit A _f is a reference video signal (white peak 100) which serves as a reference when the noise level detection unit G _g detects the noise level included in the video signal.
% Signal) is output to the video FM modulator A _b based on an instruction from the control circuit B _f . The control circuit C _f is connected to the control signal line M _c so as to exchange a control signal with the control circuit _De and to control the amplification factor of the amplifier C _b . Noise level excess notification unit D
_g, based on an instruction from the control circuit D _e via the output interface D _d, and is to perform a notification indication maintenance is required.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

A TV door phone device having the above-described structure
In the table, it works as follows and
Operated. That is, the control circuit D_eIs the lobby interface
-If there is no call between phone B and dwell unit H
Control circuit B _fAgainst the reference video signal
Output part A_fTo standard video signal (white peak 100%
Signal FM)modulationPart A_bInstruct to output to
I do.

Claims (2)

[Claims] 1. A plurality of dwelling unit terminals are connected to a multi-pair balanced cable including a video transmission path from a monitor camera, a call transmission path from a lobby intercom, and a control transmission path for propagating control data. In the TV intercom device, which allows the caller to be monitored on the residential unit terminal by a video signal sent from the monitor camera while making a call between the lobby intercom and the selected residential unit terminal, Is provided with a reference video signal output unit for outputting a reference video signal when a call is not made, and the housing unit terminal is provided with a noise level detection unit for detecting a noise level included in the received reference video signal, If the noise level exceeds a predetermined value between the monitor camera or the monitor camera and the residential unit terminal, the amplification factor may be increased. A TV intercom device, which is provided with a video signal amplification section that operates in accordance with. 2. The TV intercom apparatus according to claim 1, further comprising a noise level excess notifying unit for notifying that the noise level exceeds a predetermined value when the noise level exceeds the predetermined value.