JPH02166895A - Timer control circuit in video interphone system - Google Patents

Abstract

PURPOSE:To set the switching of power source supplying time for a telecamera and that for a monitor television with one timer circuit by switching an outside attached element to be connected to the timer circuit with a hook switch and changing the set time of a timer. CONSTITUTION:For a timer control circuit 1, a hook switch FSW is positioned at an (a) side when a handset is hung on a hook. When a calling signal is applied to a terminal TIN as the seizing of a timer circuit 1a, a driving signal is outputted from a terminal TOUT during the first set time, which is approximately 30 seconds, and supplies telecamera and monitor television power sources. Further, a visitor image photographed by a subordinate telephone set side camera is projected on the monitor television of a master telephone set. At a master telephone set side, the visitor image projected on the monitor is confirmed, and the handset is taken up. The switch FSW of a time constant switching means 1c is switched to a (b) side, capacitor C1 and C2 are additionally connected to the circuit 1a in parallel to the circuit 1a, the set time is changed to the second set time, which is approximately 3 minutes, and the driving signal is outputted from the terminal TOUT.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a television intercom system, and more specifically, the present invention is characterized by a timer control circuit that sets the time for supplying a source to a television camera and a monitor television. Concerning what you have.

[Conventional technology] In order to make it possible to see guests indoors, a television camera is installed on the side of the intercom unit installed at the entrance.
A TV intercom system, in which a monitor TV is installed on the side of the intercom base unit installed indoors so that a video can be displayed simultaneously with a call, has been developed and used.

As shown in FIG.
When the call button 200a of 00 is operated, a call signal is transmitted to the intercom unit 100 placed in the room through the signal line i, a ring tone is output from the speaker 100c, and the TV camera 200b of the slave unit 200 and the parent unit Machine 10
Power is supplied to the monitor television 100b of No. 0, and the video signal is sent to the parent Ill 00 through the wiring l, and is displayed as an image on the monitor television 100b. When the resident picks up the handset and answers the ringing tone, The speaker 200c and the microphone 200d of the child device 200 are used to communicate with each other.

By the way, in such a system, the master unit 00 and the slave unit 200 are connected by a plurality of signal lines, but as the number of wires increases and the installation work becomes extensive, A television intercom system has been developed in which video, audio, control signals, etc. are multiplexed and transmitted over a pair of signal lines.

FIG. 4 shows a block diagram of the configuration of such a television intercom system.

This system is constructed by combining an intercom base unit 100 with a monitor TV TV installed indoors and an intercom slave unit 200 with a monitor camera TVC installed at the entrance, both of which are connected using coaxial cables. The slave unit 200 is connected by a dedicated signal line l, power is supplied from the master unit 100 side, and necessary information communication is performed by multiplexing video, audio, and control signals.

To explain a more specific configuration, the intercom base unit 10
0 is a slave device power supply circuit 101.0 for supplying power to the slave device 200 side. A modulation section 105 modulates a high frequency signal using the audio signal from the handset) H and a tone signal serving as a control signal for the television camera TVC provided on the intercom slave unit 200 side. Demodulation section 104 that extracts the calling signal and voice signal by modulation fit! While manually inputting the high frequency signal outputted from 105, the demodulator 104 is connected to the slave device 200 via the signal line β.
The high frequency signal sent from the slave unit 200 is output, the output voltage of the slave power supply circuit 101 is transmitted to the slave unit side, and the slave unit 200
A balanced input/output circuit 103 and a tone signal detection circuit 104c output the video signal transmitted from the television camera TVC.
The speaker SPA outputs a calling signal according to the output signal of the speaker SPA.
a calling signal generation circuit 102 that sounds a calling signal from
The output signal of the tone signal detection circuit 104c is used as the activation signal for the first set time (approximately 3 seconds required to confirm the appearance of the visitor).
Switching circuit 1 outputs a drive signal for about 0 seconds)
The timer circuit (I) 106 that drives 0B is activated by switching the hook switch (not shown) provided on the hook F when the hunt cellar) H is picked up, and the switch jig circuit is activated to set the second setting time (necessary for a call). The modulation section 105 uses the output signal from the audio signal amplification circuit 105b that keeps the audio signal constant and amplifies it to a maximum of 3 minutes, and the output signal from the tone signal generation circuit 105c. 1 output signal and the modulation circuit 106a.
The demodulator 104 uses these signals to FM-modulate the high-frequency signal serving as the first carrier.
Here, a demodulation circuit 104a for FM demodulating the high frequency signal from the balanced input/output circuit 103, and a pre-phase 200 (j,
In order to extract speech and audio signals, the configuration includes a tone signal detection circuit 104C and an audio signal amplification circuit 104b.

In addition, the other intercom slave device 200 has a modulation section 204.
A demodulation unit 205 that demodulates the high frequency signal sent from the main device 100 side and extracts a camera control signal and an audio signal. High frequency signal output from modulation section 204 and television camera TVC
While manually inputting the video signal output from the demodulator 206
A high frequency signal is output to the main unit 10 via the signal line l.
Pre-phase power supply circuit 10 from the high frequency signal sent from the 0 side
A balanced input/output circuit 203 that outputs to the tR separation circuit 201 that separates the power supply current of 1, and a tone signal detection circuit 205C.
The camera is equipped with a camera power switch 202 that controls the supply of power to the television camera TVC based on the output signal from the microphone signal amplification circuit 204b that amplifies the microphone signal to a certain level. , the tone signal output from the tone signal generation circuit 204C in response to the operation of the call button SW is manually transmitted to the modulation circuit 204a, and these signals are used to generate a second carrier (which can be distinguished from the first carrier on the base unit side). The demodulator 205 is configured to modulate a high-frequency signal that is
Here, a demodulation circuit 205a for FM demodulating the high frequency signal from the balanced input/output circuit 203, and a tone signal detection circuit 206C for extracting a tone signal for further controlling the camera and an audio signal from the demodulated signal. , and an audio signal amplification circuit 205b.

In such a system, the base unit 100 and the preliminary phase 200 are
Connection terminals T1 and TG provided on the main unit side and connection terminals T2 and TG provided on the pre-phase side are respectively connected with the core wire and shielded outer wire of a dedicated signal line l such as a coaxial cable, and this signal line l The configuration is such that video, audio, and other control signals necessary for information communication are multiplexed and transmitted between the two via the .

By the way, in a system with such a configuration, when the call button SW of the pre-phase 200 is operated, a tone signal is output from the tone signal generation circuit 204C of the modulation section 204, and the modulation circuit 204a uses this tone signal to generate the second carrier. F
M modulates. The modulated second carrier is sent to the base unit 100 side via the balanced input/output circuit 203 and the signal line l,
Demodulator 1 via balanced input/output circuit 103 of 100 base units
04 and is FM demodulated by the demodulation circuit 104a, the tone signal is detected by the tone signal detection circuit 104C, and the ringing signal generation circuit 102 makes the speaker SPA on the base unit 100 side ring, and the timer circuit (1 )l
oe is activated, the switching circuit 108 is driven for a first set time, and power is supplied to the monitor television TV. At the same time, the output voltage of the switching circuit 108 is applied to the tone signal generation circuit 105C of the modulation section 105,
Furthermore, since the calling signal from the calling signal generating circuit 102 is applied to the audio signal amplifying circuit 105b, the modulating circuit 105
In a, the first carrier is FM-modulated with these tone signals and audio signals, and this modulated wave is transmitted to the balanced input/output circuit 103, the signal line β, and the base unit side.

The ring signal is applied to the demodulator 205 through the output circuit, and is amplified by the audio signal amplification circuit 205b, and the back tone of the ring tone is emitted from the speaker SPB.
The camera power switch 202 is driven by the output signal of the tone signal detection circuit 205c, and the source separation circuit 201
DC voltage from the TV camera TVC is supplied to the TV camera TVC.

Therefore, at the same time when the call button SW on the slave device 200 side is operated, the television camera TVC and the base device 100
Since power is supplied to the side monitor TV TV for the first set time, the video signal from the TV camera TVC is transmitted to the balanced input/output circuit 203, the signal line 2, and the balanced input/output circuit 103.
The video is sent to a monitor TV and displayed.

In this way, when the called base unit 100 side picks up the handset H from the hook F and responds by the ringing tone from the speaker SPA before the end of the first set time, the phone set on the hook F A hook switch (not shown) resets the timer circuit (1) 106 and activates the timer circuit (II) 107 to start the second
The switching circuit 10B is driven for the set time, and power is continuously supplied to the monitor television TV, and power is also continuously supplied to the television camera TVC of the preliminary phase 20011+1. Here, the voice responded by the resident using the handset H is amplified by the voice signal amplification circuit 105b, and sent to the modulation circuit 105a, where the first carrier is FM-modulated, and the FM-modulated first carrier is transmitted to the balanced input/output circuit 103, The audio signal is transmitted to the pre-phase 200 side via the coaxial cable l, and FM demodulated by the demodulation circuit 205a of the demodulation section 205 through the balanced input/output circuit 203 on the pre-phase 200 side. Phase 200
The audio from the 1fi100 side is output from the speaker SPB.

Furthermore, the audio signal input from the microphone M with a pre-phase of 200 examples is amplified by the microphone signal amplification circuit 204b, and is then amplified by the modulation circuit 204b.
04a, where the second carrier is FM modulated,
After being sent out to i*a+zoa and demodulated through the balanced input/output circuit 203, the coaxial cable 1, and the balanced input/output circuit 103 of the base unit 100, it is amplified by the audio signal amplification circuit 104b and sent to the hunt cell of the base unit 100). Prephase 200 from H
It operates to output the example audio. When the call ends and the handset H on the gvRioo side is returned to its original position, the timer circuit 107 is reset in conjunction with the hook switch (not shown), and the switching circuit 106 is turned off.
F and the power supply to the monitor TV TV is cut off, and the drive of the tone signal generation circuit of the modulation section 106 of 11111100 is stopped, so that the demodulation section 2 of the pre-phase 200
The tone signal detection circuit 205C of 05 stops detecting the tone signal, the camera power switch 206 is cut off, and the supply of power to the television camera TVC is also stopped.

Therefore, in such a TV intercom system,
When the call button on the pre-phase 200 side is operated, and the resident is away, power is supplied to the television camera TVC and monitor television TV continuously for the first set time, and then the power supply is turned off. Since it is blocked, a fixed image will not be projected for a long time from the TV camera TVC to the monitor TV TV, which prevents burn-in on the fluorescent screen of the monitor TV TV and also extends the life of the TV camera. It is said that

Further, when the resident picks up the handset and answers in response to the ringing tone, the timer circuit (I) 106 is reset, and the television camera TVC and monitor The TV is powered on and a call is made. If a call is to be made for longer than the second set time, by operating the monitor switch M SW before the second set time elapses, the timer circuit (■) 107 is restarted and the television camera TVC and The configuration is such that power is continuously supplied to the monitor television TV.

However, the television intercom system with the above configuration requires two independent timer circuits (1) and (II) to control the first and second set times, so the circuits are duplicated. Since this increases complexity and material cost, there is a need for the development of a timer control circuit that can simplify the circuit and reduce material cost using a simple method.

[Problem to be Solved by the Invention] The present invention, proposed in view of the above circumstances, changes the set time of the timer by switching the external element connected to the timer circuit using a hook switch linked to the handset. To provide a timer control circuit for a television intercom system with a simplified circuit and reduced material cost, which allows switching and setting of two power supply times for a television camera and a monitor television using a single timer circuit. The purpose is

[Means for Solving the Problems] The present invention proposed to achieve the above-mentioned object includes a TV camera provided on the intercom slave side and a monitor TV provided on the intercom base unit side. It has a timer circuit that defines the tR supply time and a hook switch that is linked to the up and down operation of the handset of the intercom III 1ffi, and the external device connected to the timer circuit by the hook switch switches the external device. time constant switching means for switching and setting the timer circuit to a first and second set time; and a time constant switching means for resetting the timer circuit and setting it again when the handset of the intercom base unit is picked up. , and a set/reset circuit that resets the timer circuit when the handset returns to its original state (corresponding to claim 1).

Further, in the second aspect of the present invention, a monitor switch is added to the timer control circuit, and when this switch is operated, the timer circuit is activated and a television camera installed in advance of the intercom is activated. Driving power is automatically supplied to the monitor television set on the intercom slave side for a time corresponding to the time set in the timer circuit.

A capacitor or a resistor is used as an external element for such a timer control circuit (corresponding to claim 3.4).

[Function] In the present invention, when the handset is in the return state, that is, when it is attached to the hook, the time constant switching means linked to the hook switch is replaced by an external element that reduces the set time in a timer circuit. Therefore, when a calling signal is input from the intercom slave side to the timer circuit, a drive signal is output from the timer circuit for the first set time, and this causes the TV camera installed on the intercom slave side to
Power is supplied to the monitor television provided on the intercom base unit side for only the first set time.

Next, when the handset is picked up before the end of the first set time, the time constant switching means interlocked with the hook switch connects the external device that increases the set time to the timer circuit, and at this time the set/ After sending a reset signal to the timer circuit, the reset circuit sends a set signal to the timer circuit again.

As a result, the timer circuit outputs a drive signal for the second set time, and as a result, the TV camera installed on the intercom slave side and the monitor TV installed on the intercom base unit output the drive signal for only the second set time. Power is supplied.

Then, when the timer circuit passes the second set time,
The drive signal of the timer circuit is automatically stopped, but the second
If the handset is returned to its original state before the set time elapses, the set/reset circuit sends a reset signal to the timer circuit, and the set/reset circuit sends a reset signal to the intercom slave side and the intercom n* side. Immediately stop power supply to the installed TV monitor.

[Example] The present invention will be described in detail below with reference to the drawings.

FIG. 1 is an explanatory diagram showing the configuration of a timer control circuit 1 of the present invention. In the figure, 1a is a timer circuit, Ib is a set/reset circuit that sends a set and reset signal to the timer circuit, and IC is a timer circuit. By switching the contacts of a hook switch FSW, which is a constant switching means and operates in conjunction with a handset (not shown) in the illustrated example, another capacitor C2 is connected in parallel to the capacitor C1 externally connected to the timer circuit 1a in advance. By connecting to the 1st setting time (set to about 30 seconds), the second setting time (set to about 3 minutes) can be switched.

The set/reset circuit 1b detects a change in the state of the handset and outputs a set signal and a reset signal. When the handset is lifted, it outputs a reset signal and then a set signal. Then, the timer circuit 1a is activated, and when the handset is restored to its original state, a reset signal is output to reset the timer circuit 1a.

In the timer control circuit l having such a configuration, when the handset (not shown) is hung on the hook (not shown), the hook switch FSW is not switched to side a,
The call signal is sent to terminal T as a starting signal for timer circuit la.
When applied to IN, the terminal T is applied only during the first set time t1.
A drive signal is output from OUT, and during this set time,
TV camera (not shown) and monitor TV (not shown)
Power is supplied to the intercom, and the image of the visitor taken by the TV camera on the intercom slave side is displayed on the monitor TV on the intercom base unit.

On the intercom base unit side, check the image of the visitor displayed on the monitor TV, pick up the handset (not shown), and switch the hook switch FSW of the time constant switching means IC.
is switched to the b side, 02 is additionally connected in parallel to the capacitor C1 in the timer circuit 1a, and the set time is changed to the second set time t2.

In addition, in this example, at this time, by switching the hook switch FSW, the power supply voltage CC is set/set via the resistor R.
Since voltage is applied to the reset circuit 1b, the set/reset circuit 1b detects this change and outputs a reset signal, and then outputs a set signal, and the timer circuit 1a outputs a voltage from the terminal T OUT for a second set time t2. Outputs a drive signal.

As a result, the power supply time to the television camera provided on the intercom slave side and the monitor television provided on the intercom base device side continues for a further second set time.

Also, if the timer circuit 1a set to the second set time completes the call with the intercom slave side and returns the handset to its original state before the second set time elapses, the set/ Reset circuit 1b is timer circuit 1a
Since reset No. 18 is output at this time, the power supplied to the television camera on the intercom slave side and the monitor television on the intercom base unit side is immediately stopped.

Note that MSW is a monitor switch, and this switch M
When the SW is operated, power is supplied to the TV camera installed on the intercom slave side and the monitor TV installed on the intercom base unit, regardless of the state of the handset. In the case where the MSW is provided, the power supply time becomes the second set time by the above-mentioned time constant disconnection means IC when the handset is lifted up, and becomes the first set time when the handset is in the wake-up state. (Corresponding to claim 2).

In the present invention, a hook switch F linked to a handset is provided.
By switching and connecting the capacitor C1 to the timer circuit 1a by switching the SW, the first and second set times can be set in one timer circuit! (corresponding to claim 3), the configuration may be such that the connection of a resistor externally attached to the timer circuit 1a is switched in conjunction with the operation of the handset (corresponding to claim 4).

Next, FIG. 2 is a block diagram showing the configuration when the above-mentioned timer control circuit 1 is incorporated into a television intercom system, and the same parts as the conventional ones are given the same reference numerals and explanations are omitted. There is.

[Effects of the Invention] According to the timer control circuit of the present invention (corresponding to the one described in claim 1), in conjunction with the operation of the handset provided on the intercom base unit side, the intercom slave side TV camera and , a TV intercom system that allows the power supply time supplied to the monitor TV installed on the intercom base unit to be switched between two set times using a single timer circuit, simplifying the circuit and reducing material costs. It is possible to provide a timer control circuit suitable for

In the timer control circuit according to claim 2, power can be supplied to the television camera installed on the intercom slave side and the monitor television installed on the intercom base unit regardless of the state of the handset. When lifted, power is supplied for a second set time, and when the handset is in the wake-up state,
Power is supplied only for the first set time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the timer control circuit of the present invention, FIG. 2 is a block diagram when the timer circuit is incorporated into a television intercom system, and FIG. 3 is a basic configuration diagram of a conventional television intercom system. FIG. 4 is a block diagram showing its detailed configuration. [Description of symbols] 1... Timer control circuit la... Timer circuit section lb... Set/reset circuit 1c... Time constant switching means A... Intercom base unit B... Intercom prephasing FSW ---Hook switch H...Handset...Signal line SW...Call button TV--Monitor TV TVC...TV camera t]...First setting time t2...Second set time

Claims (1)

[Claims] 1) An intercom base unit having a monitor television and an intercom slave unit having a television camera are connected by a signal line,
At least a video signal, a control signal, and an audio signal for a call are sent from the intercom slave unit to the interphone base unit, and at least a control signal and an audio signal for a call are sent from the interphone base unit to the interphone slave unit. When the call button provided on the slave unit side is operated, the base unit outputs a ring tone, and at the same time the TV camera on the slave unit side of the intercom is output. Power is automatically supplied to the monitor TV on the intercom base unit side for the first set time, while the handset installed on the base unit side is automatically supplied with power for the first set time. When we take up
In the TV intercom system, power is continuously supplied to the TV camera and the monitor TV for a second set time, and video and audio are transmitted via the signal line for a call. A timer control circuit that regulates the supply time of driving power to a television camera installed on the intercom slave side and a monitor television installed on the intercom base side, and is activated by a call signal from the slave side. circuit, and a hook switch that is linked to the operation of the handset of the intercom base unit, and the hook switch switches an external element externally connected to the timer circuit, so that the timer circuit can be connected to the first or second timer circuit. When the handset on the intercom base unit side is picked up, the timer circuit is reset and then set again, and when the handset returns to its original state, A timer control circuit in a television intercom system configured by combining a set/reset circuit that outputs a signal to reset the timer circuit. 2) A monitor switch is added to the above-mentioned timer control circuit, and when this switch is operated, the above-mentioned timer circuit is activated, and the TV camera installed on the intercom slave side and the monitor installed on the intercom slave side are activated. 2. The timer control circuit according to claim 1, wherein driving power is automatically supplied to the television for a time corresponding to a time set in the timer circuit. 3) The timer control circuit according to claim 1 or 2, wherein the external element is a capacitor. 4) The timer control circuit according to claim 1 or 2, wherein the external element is a resistor.