JPH09238329A - Slave set, master set, electric appliance system and tv intercom system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the TV intercom whose exposure adjustment is made by a master set side. SOLUTION: A fluctuation component detected by a slave set is superimposed on a power supply voltage fed from a feeding circuit 14 at a master set 10 by controlling switches SW1, SW2. An audio signal and a video signal are sent by one transmission line and a DC signal is superimposed on them. The slave set side divides the power supply voltage and an integration circuit is provided in a section generating a reference voltage to detect a voltage increase and decrease through the comparison with the reference voltage. The result of detection is fed to an electronic shutter control circuit, in which exposure is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TV door horn system installed in a house.

[0002]

2. Description of the Related Art Visitors press chimes at the entrance to contact their homes, but recently, in addition to these chimes, an interphone or a home visitor to talk with those at home comes in. Some have a camera to check the person. Such a thing is called a TV door horn.

As is well known for interphones, etc., when a switch is pressed by a visitor or the like, a ringer or the like of a device provided inside responds to the switch, so that a person inside the house knows the arrival of the visitor. It is like this. At this point, the camera is activated and the visitors can be confirmed. After the confirmation, if necessary, the person in the house can take off the hook and have a conversation with the visitor. The thing installed at the entrance is called the child machine, and the thing installed in the house is called the parent machine.

The slave unit is connected to the master unit via a transmission line, and signals are exchanged via this transmission line. The video signal is one-way communication from the child device to the parent device, and the audio signal is two-way communication. However, the control signal for obtaining the video signal is configured to be transmitted from the master unit to the slave unit.

In such a TV door horn, as described above, the video signal from the camera, which is the image pickup unit, the audio signal from the microphone or the audio signal to the microphone must be transmitted through one transmission path. In general, multiplexing is performed. Japanese Unexamined Patent Publication No. 62-257287 discloses a method of FM-modulating a video signal in a band different from that of an audio signal to multiplex the audio signal for transmission (conventional example 1). Also, in the method disclosed in Japanese Examined Patent Publication No. 6-83452, a multiplexing method for transmitting an audio signal and a video signal to each occupant living in the building by a TV door horn attached to a common entrance or the like. Is described (conventional example 2). In any of the conventional examples, a video signal is multiplexed with an audio signal, and the transmission line is effectively used to simplify the wiring and the like.

However, it has not been possible to multiplex a power supply (DC signal) and the like into an audio signal and a video signal for transmission, and the power supply is provided separately for the master unit and the slave unit. Further, even in a configuration in which power is supplied from the master unit to the slave unit, only the power supply line has to be separately provided, which causes a problem that the wiring becomes complicated. Furthermore, since a route for wiring has to be provided, there is a problem that the number of parts increases. In order to improve this, measures are taken such that the power source is further multiplexed on the transmission path where the audio signal and the video signal are multiplexed from the power source to the slave unit side, and the power source on the slave unit side is omitted.

However, if such an improvement is made, with the conventional interphone, if the image picked up by the handset side is difficult to see (for example, backlight), adjustment by the base side is almost impossible. Met.

[0008]

As described above, in the conventional interphone or the like, the exposure adjustment and the like are all performed automatically. Therefore, when the display on the display unit is difficult to see, the adjustment can be performed on the base unit side. could not.

In view of the above problems, an object of the present invention is to provide a TV door horn in which the master unit can manually adjust the exposure.

[0010]

In order to solve the above-mentioned problems, in the base unit used in the TV doorphone of the present invention according to claim 1 of the present invention, data is transmitted from the slave unit via the transmission path. A signal separation unit that separates and receives a video signal and an audio signal; a video signal processing unit that demodulates the video signal of the signals separated by the signal separation unit and displays it as a video from the display unit; Of the signals separated by the separation unit,
A voice output unit that outputs an electric signal sent from the slave unit as a voice; a voice input unit that sends voice to the slave unit as an electric signal; between the voice input unit and the voice output unit and the signal separation unit And an impedance converter that sends an electric signal from the voice input unit to the slave unit and sends an electric signal sent from the slave unit to the voice output unit; and creates a plurality of DC power supplies from a commercial power supply. A power supply unit for supplying one direct-current power supply from the created power supply to the slave unit side through the transmission path; a switch is provided, and by operating this switch, the power supply unit multiplexes and transmits the slave unit. And a control signal generation unit for transmitting a signal that fluctuates within a predetermined range to the direct current power source and transmitting the signal to the slave unit.

A specific configuration of the control signal generating section according to claim 1 is the invention according to claim 2,
The control signal generating unit includes a first series circuit having a plurality of diodes connected to each other, with the anode side of the diode facing the DC power source side to be fed to the slave unit side and the cathode side facing the output end of the power feeding unit. A collector and an emitter are connected to both ends of at least one diode among a plurality of diodes included in the first series circuit, and it is possible to select whether to pass through at least one diode or bypass the diode. A first transistor including: a first switch; a signal processing unit that supplies a signal for selecting a path to the base of the first transistor by operating the switch; and an anode directed to the first series circuit. A second series circuit having a plurality of diodes, one end of which is connected and the other end of which is connected to an output end of the power supply unit; and the second series circuit, A second transistor having a collector and an emitter connected to both ends of at least one diode of the plurality of diodes, the second transistor being selectable to pass through the at least one diode or bypass the diode; And a signal processing unit for supplying a signal for selecting a path to the base of the second transistor by operating the switch.

Further, it is preferable that the type of diode used in the control signal generating section is a silicon diode.
It was shown to.

Here, since the forward voltage of the silicon diode is used, the silicon diode is limited.

An electrical equipment system including the slave unit according to claim 1 and a device body is the invention according to claim 4.

In the electric equipment system including the master unit according to the fourth aspect, the control signal superimposed on the DC power supply voltage can be transmitted to the slave unit side. That is, it becomes possible to multiplex the audio signal, the video signal, the DC power supply, and the control signal and transmit them to the slave unit side through one transmission path.

Further, the invention described in claim 5 is the one in which the configuration of the slave unit is described because it receives the control signal generated on the master unit side and superposed on the DC power supply voltage.

According to a fifth aspect of the present invention, in a slave unit, an image pickup unit having an adjusting unit capable of electrically adjusting a shutter speed; a microphone; a video signal from the image pickup unit and an audio signal from the microphone. And a transmitting unit for transmitting a signal from the multiplexing unit to the same transmission line; a power supply fed from the master unit on the transmission line is separated from an audio signal and a video signal. A power receiving unit for receiving power; an electronic shutter control circuit provided in a subsequent stage of the power receiving unit, for putting on a power source from a master unit, extracting only a fluctuation component of direct current sent thereto, and supplying a control signal to the adjusting unit; A power supply circuit for generating a plurality of direct current power supplies from the power supply received by the unit; and a capacitor provided in the input stage of the power supply circuit for slowing the response to the fluctuation component.

Further, the inventions described in claims 6 and 7 show a specific configuration of the electronic shutter control circuit described in claim 5.

An electronic shutter control circuit according to a sixth aspect of the present invention includes an integrating circuit which outputs a stable voltage even if there is a change;
And a differentiating circuit for extracting only the fluctuation component.

That is, in order to extract and reproduce the control signal superimposed on the slave unit side, and to extract the fluctuation component in the master unit,
The differentiating circuit is provided with an integrating circuit in order to take out a stable voltage even if there is a change.

The invention according to claim 7 shows a specific configuration of the differentiating circuit and the integrating circuit.

According to another aspect of the electronic shutter control circuit of the present invention, one is connected to the output end of the power receiving circuit and the other is connected to the reference potential point, and a dividing circuit for dividing the power supply voltage and supplying the voltage to the subsequent stage; Of the power supply voltage divided into three by the dividing circuit, the largest voltage is supplied to the inverting terminal and the central voltage is supplied to the non-inverting terminal via the analog switch equipped with the control terminal and sent from the master unit. A first operational amplifier circuit that detects only the fluctuation component due to the voltage drop among the fluctuation components; the lowest voltage of the power supply voltages divided into three by the dividing circuit is at the non-inverting terminal, A second operational amplifier circuit, in which the voltage is supplied to the inverting terminal via the analog switch and detects only the fluctuation component due to the voltage rise, of the fluctuation components of the DC signal sent from the parent device; Of the voltage divided by The central voltage is provided in the path that gives the first and second operational amplifier circuits, and even if the analog switch is disconnected, the voltage before the switch is pressed is output, and even if there is a fluctuation, An integrator circuit that slows the response; a signal that disconnects a path that supplies a reference voltage to a terminal of the operational amplifier circuit when the output of the first or second operational amplifier circuit is at a high level And a reset circuit for supplying to the control terminal of the switch.

Further, in the invention described in claim 7, the integrator circuit is provided for creating the reference voltage. However, in claim 8, the fluctuation of the voltage supplied from the master unit is removed and a stable voltage is obtained. In order to supply to each circuit of, the input side of the part that creates the power supply for the slave unit is also provided with an integrating capacitor.

The structure of the present invention is the invention of claim 8.

According to an eighth aspect of the present invention, an image pickup unit having an adjusting unit capable of electrically adjusting a shutter speed; and whether the exposure adjustment is manually or automatically adjusted. A switching unit for transmitting to the unit; a microphone; a multiplexing unit for multiplexing a video signal from the imaging unit and an audio signal from the microphone; and a sending unit for sending the signal from the multiplexing unit to the same transmission path. A power receiving unit that separates the power source supplied from the master unit from the audio signal and the video signal through the transmission path to receive the power; and a direct current that is provided after the power receiving unit An electronic shutter control circuit that extracts only a fluctuation component and supplies a control signal to the adjustment unit, a power supply circuit that creates a plurality of DC power supplies from a power supply received by the power reception unit; and an input stage of the power supply circuit. It is provided to deal with the fluctuation component And a capacitor to slow the response,
Is provided.

The invention of claim 9 shows the configuration of an electric device system comprising the slave unit according to claim 5 or 8 and a device body.

Further, a TV door horn system is configured by using the electric equipment system according to claim 4; and the electric equipment system according to claim 9.
It is the invention described in 0.

[0028]

Embodiments of the present invention will be described with reference to the drawings. 1 to 4 are diagrams showing a configuration of a TV door horn which is an embodiment of the present invention. FIG. 1 is a block diagram of a master unit, and FIG. 2 is a switch unit and a power supply circuit for exposure adjustment of FIG. Shows a specific configuration of. 3 shows a block diagram of the slave unit, and FIG. 4 shows a specific configuration of the electronic shutter control circuit of FIG.

On the side of the base unit 10, a commercial power source (AC100
V) creates various DC power supplies in the power supply circuit 11 and supplies them to each circuit. This portion is composed of an AC / DC converter, a so-called AC-DC converter, a DC-DC converter, a so-called DC-DC converter, and the like.

FIG. 1 shows only an LCD power supply (for example, 6V) 13 supplied to the LCD unit 12 which is a monitor unit and a DC power supply (for example, 15V) for driving a camera or the like provided on the slave unit side. There is. A power supply circuit 14 is provided to supply power to the slave unit, and the output terminal of the power supply circuit 14 is connected to the transformer T1 side of the choke coil L1 provided to separate the video signal and the audio signal. I am doing it. The choke coil L1 of this base unit 10 is
It is provided so as to send the video signal sent from the camera of the slave unit only to the LCD unit 12 which is the monitor unit via the FM demodulation circuit 15. That is, the voice signal sent from the child device does not go to the monitor (LCD unit) side as it is, but passes through the choke coil L1 and the transformer T1 and is a voice input unit and a voice output unit such as a telephone or a speaker. To the intercom terminal circuit 16. In the case of the monitor type, it is connected to a telephone or other voice interphone, and in the case of a single parent-child TV doorphone, it is connected to a handset, and those handset signals are transmitted between the parent and child through a transformer T1. The call is made.

The choke coil L1 is provided to separate the audio signal and the video signal so that the video signal does not leak into the audio system or the power supply system. For example, a video signal has a frequency band (for example, MH) different from the baseband (10 KHz or less) of the audio signal.
If modulated in the slave unit side in the z band) and transmitted, a more reliable signal separation can be performed by providing a filter (for example, a high-pass filter) or the like in the FM demodulation circuit 15 of the master unit.

Further, in order to omit the power supply on the side of the slave unit, the power is supplied to the slave unit on the transmission path for transmitting the audio signal and the video signal. Therefore, the power feeding circuit 14
It is quite conceivable that the audio signal leaks from the transmission line 17 to the. In order to avoid this, the power feeding circuit 14 is provided so that the power feeding unit 14 has a high impedance with respect to the transmission line 17 only for AC signals, that is, audio signals. A DC cut capacitor C1 for blocking the entry of a DC voltage is provided on the transformer T1 side. That is, the power feeding circuit 14 having a high impedance in AC is provided by branching to the transmission line 17, and the transmission line 17 through which the audio signal passes.
That is, the power feeding circuit 14 is configured so that the power feeding unit 14 does not affect the power feeding circuit 14 and the audio signal does not affect the power feeding circuit 14. Here, the transmission line 17 is composed of an 8 ohm system, which is the electric impedance of the speaker. On the other hand, if a feeding circuit 14 having a high impedance in terms of alternating current is provided, the signal can be easily separated. Is.

Further, here, in order to avoid a case where the sound is interrupted due to switching after the hook is detected, a mute section or the like is provided to block the incoming and outgoing of the audio signal. This part is the switching noise prevention circuit 18A,
The hook detection circuit 18B detects a hook signal from a telephone or the like which is a voice input and a voice output, and the timer control circuit 18 which receives the signal detects a switching noise prevention circuit 18
The configuration is such that a mute signal is sent to A. Also,
A circuit 18C for short circuit prevention is provided for safety. Further, the timer is operated by the timer control circuit 18 in order to control the monitor time or the call time. A call detection circuit 19 for detecting a call on the slave side is also provided.

Further, by utilizing the fact that the power is supplied to the slave side in a multiplexed manner on the transmission path, the present applicant makes the voltage of the power source fluctuate and uses this as a control signal for the slave side. Is devised so that it can be detected by. That is, the control signal generation unit 14A having a switch for exposure adjustment is provided in the portion of the power supply circuit 14 that supplies power to the slave unit side, and this is supplied to the slave unit side together with the power supply voltage. On the slave side,
Receiving this, only the fluctuation component is extracted by the differentiating circuit, and an integrating circuit is installed in the part where it is not necessary to fluctuate even if there is fluctuation.
It is only necessary to keep a stable voltage.

A specific configuration of the control signal generator on the master side will be described with reference to FIG. In the power supply circuit 14, a control signal generating unit 14A including a transistor and a diode is provided in the power supply circuit 14 in order to apply a change in the drop voltage when the diode is energized to the slave unit side by operating the switch. As shown in FIG. 2, the adjustment switches SW1 and SW2 provided on the master unit side are connected to the reference potential point by pressing the switches. That is, if the switch is not pressed, the pull-up resistors R21 and R22 pull down the high level portion to the low level by operating the switch. Further, since the switch is provided with two switches, an up SW1 and a down SW2, if the handset detects that these switches have been pressed,
That is, the shutter speed can be adjusted to the high speed side or the low speed side.

First, the case where both switches SW1 and SW2 are not pressed will be described. In this case, on the side where the shutter speed is increased (UP side), the input side of the Schmitt type inverter IC21 is at high level, and the transistor Q21 is non-conductive. On the other hand, on the side where the shutter speed is decreased (DOWN side), the base potential of the transistor Q22 becomes high level due to the pull-up resistor R2, the transistor Q22 becomes conductive, and further the transistor Q23 becomes conductive. Therefore, from the diodes D21 and D22 to the transistor Q2.
Power will be supplied to the handset side through the route passing through 3, and 2 diodes (1.2V that can obtain a voltage drop of approximately 0.6V with one diode) will be supplied to the handset side. You can do it. This is the reference voltage when the switches SW1 and SW2 are not pressed.

Next, a case where the up-side switch SW1 is pressed to increase the shutter speed will be described.
In this case, the potential on the input side of the Schmitt type inverter IC21 drops to a low level because the switch SW1 contacts the reference potential point. Therefore, a high level signal is applied to the base of the transistor Q21, which is the output side of the inverter IC21, and the transistor Q21,
The transistor Q24 becomes conductive one after another. Therefore,
Since the voltage to be supplied is determined by the path of the transistor Q24 and the transistor Q23, a voltage higher by 1.2 V than the voltage when it is not pressed is supplied to the slave unit side. If this can be detected on the slave side, the shutter speed can be changed to the up side.

Next, the case where the down-side switch SW2 is pressed in order to reduce the shutter speed will be described.
In this case, the base of the transistor Q22 drops to the low level, so that the transistor Q22 becomes non-conductive.
Therefore, the transistor Q23 also becomes non-conductive, and the diodes D21 to D24 and the voltage dropped by four voltages are supplied to the slave unit side. That is, a diode is provided between the power supply circuit and the output section of the power supply circuit, and the voltage to be supplied to the slave unit side can be output with a fluctuation range corresponding to the voltage drop of the four diodes D21 to D24. It is a translation. Therefore, if this can be detected on the slave side, the shutter speed can be changed to the down side.

The collector of the transistor Q25 is directly connected to the base of the transistor Q26, and the base of the transistor Q26 is connected to the power supply circuit 11 via the resistor R23.
A capacitor C21 and a resistor R2 for stabilizing the base voltage are provided between the base of 25 and the output end of the power feeding circuit 14.
4 are connected. The same is true of the base side of the transistor Q26, and the capacitor C22 and the resistor R23 are connected to the power supply circuit 11. Also, the resistance R25
R32 to R32 are provided for current adjustment or voltage adjustment, respectively.

On the other hand, an electronic shutter control circuit 40 is provided on the slave side in order to detect the control signal generated by the master. The relationship between this part and the control signal creation unit 14A provided in the master device 10 is a block on the slave device side.
This will be described with reference to FIG. First, the overall configuration of the slave unit will be briefly described.

The slave unit is provided with a portion for receiving a DC power source from the transmission line 16 and supplies power to each circuit. Here, the AC high impedance circuit 31 is a power receiving circuit. Further, a power supply circuit 32 creates a power supply for operation that requires each circuit from the DC power supply received by the power reception circuit 31. One of the power supplies for this operation is used as the video signal generation circuit 33 and the FM modulation circuit 3.
4 and the like to operate each circuit. A signal from a camera (not shown) is supplied to the video signal generation circuit 33, and this signal is FM-modulated and output to the master unit side. Since the video signal is multiplexed and transmitted on the same transmission line 17 as the audio signal, the FM modulation circuit 34 modulates the signal in a band different from that of the audio signal and transmits the signal. Further, choke coils L31 and L32 are provided on the audio signal processing side in order to prevent leakage of audio or power supply system.

In addition, a diode bridge 35 is provided in a portion for exchanging audio signals in order to obtain only a stable positive power source. The audio signal from the base unit passes through the diode bridge 35 and is output as audio from the speaker 36. In addition, since the voice is sent to the base unit 10,
The electric signal from the provided microphone 37 is transmitted to the master device 10 via the microphone amplifier 38.

The power supplied from the base unit 10 is received by the AC high impedance circuit 31 which is a power receiving circuit, and is separated from the audio signal here, and the power supply circuit 32 at the subsequent stage.
Power is being supplied from the base unit to. This power receiving circuit 3
1, a call switch portion SW31 is provided in parallel with 1, and a call signal generation circuit 39 is also provided.
By pushing the call switch SW31, the transistor Q31 becomes conductive, and the current is supplied from the power supply from the master unit. The resistor R31 is provided to apply a voltage to the base, and the resistor R32 is provided to adjust the amount of current flowing through the transistor.

Conventionally, since the call signal generation circuit 39 is not provided, the change by the call switch SW31 cannot be transmitted to the base unit 10 after the camera is operated. To enable this, call switch SW3
A call signal generation circuit 39 for detecting the second and subsequent calls is provided in the circuit including 1. Further, in order to detect the control signal sent from the parent device, an electronic shutter control circuit 40 is provided at the subsequent stage of the power receiving circuit. Further, the electronic shutter control circuit 40 is connected to the calling signal generation circuit so that the electronic shutter control circuit can be reset at the same time when the portion detecting the second and subsequent callings operates.

A specific circuit of the electronic shutter control circuit 40 is shown in FIG. 4 and will be described in detail. As shown in FIG. 4, a voltage divider circuit (R41 to R4) formed by resistors is provided at the output end of the power receiving circuit 31.
6) is connected. Among the voltages created by this voltage dividing circuit, the largest voltage is supplied to the inverting terminal (−) of the operational amplifier circuit OP41. Further, the smallest voltage is supplied to the non-inverting terminal (+) of the operational amplifier circuit. The reference voltage is a central value voltage, and this voltage is set to each operational amplifier circuit OP41,
It is supplied to the other terminal of OP42.

An integrating capacitor C41 is connected to the reference potential point so that the voltage does not change so suddenly even if the voltage changes. Further, in order to prevent the reference voltage from fluctuating in the same manner as the voltage fluctuation component, the analog switch SW41 is also used to disconnect the connection so as not to affect the comparison with the reference voltage. The analog switch SW41 is disconnected when the comparison is made, and is connected again when the voltage returns to the original level.
In FIG. 4, the portion indicated by CONT is a control terminal. That is, the operational amplifier circuits OP41 and OP4 which are comparators.
After detecting the rise or fall of 2, the connection of the path for supplying the reference voltage is once disconnected, and then the connection is made at the time when the fluctuation component disappears and the voltage returns to the original.

Since one of the logic level signals is output to the output section of each of the operational amplifier circuits OP41 and OP42, if this signal is supplied to the shutter control terminal of the electronic shutter control circuit 40, it interlocks with the switch. You can adjust the exposure. Further, in order to perform a power-on reset, an analog switch SW42 is provided, and when the power is turned on, the analog switch SW42 is connected and reset. This portion is a portion composed of the resistor R47, the capacitor C42, and the diode D41. Here, the base of the transistor Q41 is connected to the reference potential point and reset only when the power is turned on.

Further, the video signal generating circuit 33 to which the control signal is supplied from the electronic shutter control circuit 40 will be referred to. The video signal generation circuit 33, as shown in FIG.
CD sensor 51, CCD drive circuit 52, and CDS circuit (correlation double sampling circuit; Cor)
The abbreviation for Related Double Sampling) 53 and the process circuit 54 are provided. CCD drive circuit 52 to C
A signal (Φ for driving the shift register in the CD sensor 51
V, ΦH) are respectively supplied. The voltage is supplied via a V drive circuit 55 that drives the vertical shift register.

The video signal output (VIDEO) is set to F
It is sent to the M modulation circuit 34. In addition, the level comparator can automatically adjust the electronic shutter according to the result of photometry. In addition, the control signal from the electronic shutter control circuit 40 of FIG.
1 and CONT2, and the signals from the level comparator or the signal from FIG. 4 can be selected by the analog switches 55 to 58. That is, automatic exposure or manual exposure can be switched. To the shutter control terminals SC1 and SC2 of the CCD drive circuit 52, adjustment switches SW1 and SW
That is, a control signal linked with 2 is supplied. Note that CC
An iris drive circuit for exposure adjustment is provided in the D drive circuit 52.

The relationship between the CCD drive circuit 52 and the electronic shutter control circuit 40 shown in FIG. 4 will be described with reference to FIG. Here, when sc1 is high level and sc2 is low level, the shutter speed is controlled to the low speed side, and when sc1 is low level and sc2 is high level, the shutter speed is controlled to the high speed side. Both are not at high level, and the shutter is adjusted when one of the signals is at high level. Normally, both are at the low level, and it is possible to detect whether or not the switch is pressed.

Further, automatic or manual switching units (analog switches) 55 to 59 are provided on the path to the CCD drive circuit 52, and an automatic control signal is supplied to the CCD drive circuit 52 or a manual control signal is supplied. Whether the signal is supplied to the CCD drive circuit 52 is switched. If a switch or the like for switching is provided and a low or high signal is supplied to the control terminal, automatic or manual control can be easily switched. Here, the manual control is assumed.

That is, the control signal from the electronic shutter control circuit 40 is supplied to the CCD drive circuit 52 through the path of FIG. 5 (portions indicated by CONT1 and CONT2 in the figure). Therefore, the exposure adjustment (especially the backlight) on the slave side can be performed by the switches SW1 and SW2 on the master side. Of course, if not necessary, switch to automatic control and activate the camera.

Further, although the control signal is sent from the master unit 10 to the slave unit 30 as a DC signal by multiplexing on the transmission line 17, a large capacitor C31 is provided at the input stage of the power supply circuit. The fluctuation does not affect the power supply circuit. In other words, the integration circuit is connected to the input side of the power supply circuit 32 part that creates a plurality of power supplies from the power supply fed from the master unit.
It was used so that there would be no effect even if there were fluctuations. Also,
The integrating circuit is also used here to detect a fluctuation component and to generate a necessary reference voltage (reference voltage of the comparison circuit in the electronic shutter control circuit 40). Therefore,
It is possible to superimpose the fluctuation component of the DC signal on one transmission line in which the audio signal, the video signal, and the power supply are multiplexed, detect this in the preceding stage of the power supply circuit 32, and control the electronic shutter.

Further, FIG. 6 shows the external appearance of a device accommodating the master unit and the slave unit. Figure 6 shows the appearance of the base unit,
It is the figure which looked at the apparatus from the front. The monitor button of the parent device is the monitor button 61 shown in FIG.
When you put in, the image of the entrance is displayed on the LCD screen 62. Further, the backlight adjustment portion is the exposure adjustment switch portion 63, which corresponds to the up and down adjustment switch portion. The LCD screen, which is the monitor unit, is located in the center of FIG. 6, and the voice input and output units, the transmitting and receiving units, are on the left side of FIG.

Further, FIG. 7 shows the slave unit side, and is a front view. A portion indicated by the reference numeral in FIG. 7 is a camera unit 71 which is an image pickup unit, and a microphone 72 and a speaker 73 are housed in the device body 70. An LED section 74, which is a load for detecting a call, is provided below the camera section 71, and a camera window 75 is provided below the LED section 74.
Since the backlight is automatically adjusted in this part, photometry is performed. Further, the call button 76 is provided below the speaker 73 when viewed from the front. This call button 76
Corresponds to the call switch SW31.

FIGS. 8 and 9 are rear views of the master unit and the slave unit. The connection terminal portion 81 of FIG. 8 and the connection terminal portion 91 of FIG. 9 are connected to form a TV door horn. is there.

[0057]

As described above, according to the present invention as set forth in the claims, a control signal is added to a DC signal without adding a control code to a signal encoded by a modulation signal or a digital signal. This has the effect that the camera on the slave side can be controlled by the master side.

Further, there is an effect that wiring between the slave unit and the master unit can be simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a door horn, which is an embodiment of the present invention, on a slave unit side.

FIG. 2 is a diagram showing a specific circuit of a control signal generation unit in FIG.

FIG. 3 is a diagram showing a configuration of a door horn, which is an embodiment of the present invention, on a base unit side.

FIG. 4 is a diagram showing a specific circuit of the electronic shutter control circuit of FIG.

FIG. 5 shows a part of a path until a control signal is sent to an iris drive circuit provided in a video signal generation circuit.

FIG. 6 is a front view showing the outer appearance of the base unit of the door horn according to the embodiment of the present invention.

FIG. 7 is a rear view showing the outer appearance of the base unit of the door horn according to the embodiment of the present invention.

FIG. 8 is a front view showing the outer appearance of the slave unit of the door horn which is the embodiment of the present invention.

FIG. 9 is a rear view showing the outer appearance of the slave unit of the door horn which is the embodiment of the present invention.

[Explanation of symbols]

 10 ... Parent device 14 ... Power supply circuit 14A ... Control signal creation unit 30 ... Handset device 40 ... Electronic shutter control circuit SW1, SW2 ... Exposure adjustment switch OP41, OP42 ... Comparison circuit

Claims (10)

[Claims] 1. A signal separating unit for separating and receiving a video signal and an audio signal transmitted from a slave unit through a transmission path; and demodulating a video signal of the signals separated by the signal separating unit. , A video signal processing unit for displaying as a video from the display unit;
Of the signals separated by the signal separation unit, an audio output unit that outputs the electric signal sent from the slave unit side as a sound; a sound input unit that sends the sound as an electric signal to the slave unit side through the transmission path And an electric signal that is provided between the voice input unit and the voice output unit and the signal separation unit and that sends an electric signal from the voice input unit to the handset unit and an electric signal sent from the handset unit to the voice output unit. An impedance converter that sends a signal; a power supply unit that creates a plurality of DC power supplies from a commercial power supply and supplies one DC power supply from the created power supplies to the slave unit side together with a voice signal through the transmission path; A switch is provided, and by operating this switch, a signal varying in a predetermined range is placed on the DC power supply multiplexed from the power feeding unit to the slave unit and sent,
A master unit, comprising: a control signal creation unit for transmitting to the slave unit side. 2. The control signal generating section includes a plurality of diodes connected to each other, with the anode side of the diode facing the DC power source side for powering the slave unit side and the cathode side facing the output end of the power feeding section. One series circuit; a collector and an emitter are connected to both ends of at least one diode among a plurality of diodes included in the first series circuit, and the series and one pass through at least one diode or bypass the diode. A first transistor that enables selection of a signal; a first switch; and a signal processing unit that supplies a signal for selecting a path to the base of the first transistor by operating this switch; and the first series A second series circuit having a plurality of diodes whose anode is directed to the circuit, one end of which is connected, and the other end of which is connected to the output end of the power feeding unit; A second transistor having a collector and an emitter connected to both ends of at least one diode among a plurality of diodes included in the path, the second transistor being selectable to pass through the at least one diode or bypass the diode; The master unit according to claim 1, further comprising: a second switch, and a signal processing unit that supplies a signal for selecting a path to the base of the second transistor by operating the switch. . 3. The master unit according to claim 2, wherein the diode is a silicon diode. 4. An electric device system comprising: the parent device according to claim 1; and a device body. 5. An image pickup unit having an adjusting unit capable of electrically adjusting a shutter speed; a microphone; a multiplexing unit for multiplexing a video signal from the image pickup unit and an audio signal from the microphone; A sending unit for sending the signal from the multiplexing unit to the same transmission line; a power receiving unit for receiving power by separating the power source fed from the master unit from the audio signal and the video signal on the transmission line; the latter stage of the power receiving unit An electronic shutter control circuit provided on the power supply from the master unit, extracting only the fluctuation component of the transmitted direct current and supplying a control signal to the adjusting unit; And a power supply circuit for generating a DC power supply; 6. The electronic shutter control circuit includes an integrating circuit that outputs a stable voltage even if there is a change;
The slave unit according to claim 5, further comprising: a differentiating circuit that extracts only the fluctuation component. 7. An electronic shutter control circuit, one of which is connected to an output terminal of a power receiving circuit and the other of which is connected to a reference potential point and which divides a power supply voltage to supply a voltage to a subsequent stage; Of the power supply voltage divided into three,
The largest voltage is supplied to the inverting terminal, and the central voltage is supplied to the non-inverting terminal via the analog switch equipped with the control terminal. A first operational amplifier circuit for detecting;
Of the power supply voltage divided into three by the division circuit, the lowest voltage is supplied to the non-inverting terminal and the central voltage is supplied to the inverting terminal via the analog switch, and the DC signal sent from the parent device is supplied. A second operational amplifier circuit that detects only a variable component due to a rise in voltage among the variable components; and to a terminal of the operational amplifier circuit when the output of the first or second operational amplifier circuit becomes high level. A reset circuit for supplying a signal for disconnecting a path for supplying a reference voltage to the control terminal of the analog switch; and a central voltage of the voltages divided by the dividing circuit to the first and second operational amplifier circuits. Even if the analog switch is disconnected in the path to be given, the voltage before the switch on the master unit side is pressed and the voltage fluctuates and the response due to this fluctuation is slowed down. Handset of claim 5, characterized by comprising a; and minute circuit. 8. An image pickup unit having an adjusting unit for electrically adjusting a shutter speed; a switching unit for notifying the adjusting unit whether to manually or automatically adjust the exposure; and a microphone. A multiplexing unit that multiplexes a video signal from the imaging unit and an audio signal from the microphone; a sending unit that sends the signal from the multiplexing unit to the same transmission path; A power receiving unit that receives the power supplied from the audio signal and the video signal separately; a power receiving unit that is provided in the latter stage of the power receiving unit, puts the power from the master unit, extracts only the fluctuation component of the DC that is sent, and performs the adjustment An electronic shutter control circuit that supplies a control signal to the power supply unit; a power supply circuit that creates a plurality of DC power supplies from the power supply received by the power receiving unit; provided at the input stage of the power supply circuit, and has a slow response to fluctuation components With a capacitor to Handset, characterized by comprising a. 9. An electric device system comprising: the slave unit according to claim 5; and a device body. 10. The electric device system according to claim 4,
A TV door horn system comprising: the electric device system according to claim 9.