JP2009206950A - Interphone device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To transmit a video signal to an extended master unit without amplifying any video signal by a living room master unit by installing a branch transformer in the living room master unit in an intercom device, and to achieve the balanced transmission of a data signal in the same way as video signal transmission by installing a transformer for data, and to improve speech communication quality by preventing any data signal from being mixed with a voice. <P>SOLUTION: When connecting a front door slave unit through an extended transmission line to an extended master unit by relaying a living room master unit, a branch transformer connected to a transmission line for transmitting a video signal through an extended transmission line is installed in the living room master unit. Also, the front door slave unit and the living room master unit and the extended master unit are respectively installed with a transformer for data for multiplexing a data signal with a video signal and a voice signal, and for performing the balanced transmission of the data signal on the transmission line and the extended transmission line. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an intercom device including an entrance cordless handset, a living room base phone, and an extension base phone, and in particular, can transmit video signals from the entrance cordless handset at low cost and can improve call quality. The present invention relates to an intercom device.

  2. Description of the Related Art Conventionally, interphone apparatuses including an entrance slave unit, a room master unit, and an extension master unit that multiplex and transmit signals are well known (see, for example, Patent Document 1 and Patent Document 2).

  The intercom device (TV door phone device) described in Patent Document 1 is a device that multiplexes and transmits an audio signal and a video signal, while the interphone device (monitoring / calling system for collective housing) described in Patent Document 2 is an audio signal. (Voice data) and control signals (control data) are multiplexed and transmitted.

  As an example of an interphone device provided with such an entrance child device, a living room parent device, and an extension parent device, an interphone device having a circuit configuration as shown in FIG. The conventional intercom apparatus shown in FIG. 4 will be described below with respect to transmission of video signals and data signals.

  The intercom apparatus shown in FIG. 4 includes an entrance slave unit 213, a living room master unit 234, and an extension master unit 248. The entrance slave unit 213 and the living room master unit 234 are connected by a transmission line 214. They are connected by a transmission line 235.

  The entrance cordless handset 213 includes a camera 200, an FM modulation circuit 201, an FM amplifier 202, an LPF (Low Pass Filter) 203, and an FM transformer 204 as video signal transmission circuits. The FM transformer 204 is a transmission line 214. It is connected to the.

  As a data signal transmission circuit, a CPU 206, an ASK (Amplitude Shift Keying) modulation circuit 207, an LPF 208, an ASK demodulation circuit 209, a BPF (Band Pass Filter) 210, a 2W-4W conversion circuit 211, a diode bridge 212, and a choke coil 205 are provided. The choke coil 205 is connected to the transmission line 214. The 2W-4W conversion circuit 211 is connected to a call circuit including a microphone and a speaker.

  Next, the office base unit 234 is provided with an FM transformer 219, an FM amplifier 218, an FM demodulation circuit 217, a video amplifier 216, and a monitor 215, which are connected from the transmission line 214, as a video signal transmission circuit, and an LPF 227. And an FM transformer 228 connected to the transmission line 235.

  In addition, as a data signal transmission circuit, CPU 220, ASK modulation circuit 221, LPF 222, ASK demodulation circuit 223, BPF 224, 2W-4W conversion circuit 225, choke coil 226, ASK modulation circuit 229, LPF 230, ASK demodulation circuit 231, BPF 232, 2W -4W conversion circuit 233 is provided. The 2W-4W conversion circuit 225 is connected to a call circuit including a microphone and a speaker.

  Further, the extension base unit 248 is provided with an FM transformer 240, an FM amplifier 239, an FM demodulation circuit 238, a video amplifier 237, and a monitor 236 connected from a transmission line 235 as a video signal transmission circuit, and a data signal. As a transmission circuit, a CPU 241, an ASK modulation circuit 242, an LPF 243, an ASK demodulation circuit 244, a BPF 245, a 2W-4W conversion circuit 246, and a choke coil 247 are provided, and this choke coil 247 is connected to the transmission line 235. The 2W-4W conversion circuit 246 is connected to a call circuit including a microphone and a speaker.

  In the conventional intercom apparatus having such a circuit configuration, the video signal is unidirectionally transmitted from the front door unit 213 to the living room base unit 234 and the extension base unit 248, and is captured by the camera 200 of the front door unit 213. The video is FM-modulated by a carrier wave of 12 MHz by the FM modulation circuit 201, and is output to the transmission line 214 via the FM amplifier 202, LPF 203, and FM transformer 204.

  The video signal sent via the transmission line 214 is sent to the FM demodulation circuit 217 via the FM transformer 219 and the FM amplifier 218 of the living room master unit 234. The video signal demodulated by the FM demodulating circuit 217 is adjusted to an appropriate level by the video amplifier 216 and then input to the monitor 215 so that the video is displayed on the monitor screen.

  The output signal of the FM amplifier 218 is output to the transmission line 235 via the LPF 227 and the FM transformer 228 and sent to the extension base unit 248. In other words, the video signal from the entrance slave 213 is sent to the extension master 248 via the living room master 234.

  The video signal reception at the extension base unit 248 is the same as that at the base unit 234, and the video is displayed on the monitor 236 via the FM transformer 240, the FM amplifier 239, the FM demodulation circuit 238, and the video amplifier 237.

  On the other hand, data signal transmission will be described. Data signals are transmitted between the entrance cordless handset 213 and the room master 234, and between the room master 234 and the extension master 248, and perform data communication necessary for the control operation of each device. It is.

  As an example, data signal transmission from the living room master 234 to the entrance slave 213 will be described. First, a data signal such as an audio signal or a camera operation control signal output from the CPU 220 is modulated by the ASK modulation circuit 221 with a 32 kHz carrier wave, and is output to the transmission line 214 via the LPF 222 and 2W-4W conversion circuit 225. The data signal sent via the transmission line 214 is received via the choke coil 205, the diode bridge 212, and the 2W-4W conversion circuit 211 of the entrance cordless handset 213, and demodulated via the BPF 210 and the ASK demodulation circuit 209. , Input to the CPU 206.

  The transmission / reception circuit for data transmission is the same for the entrance slave unit 213, the living room master unit 234, and the extension master unit 248.

Japanese Patent Laid-Open No. 11-284959 JP 2005-236581 A

  As described above, the conventional intercom apparatus requires the LPF 227 and the FM transformer 228 to relay the video signal from the living room base unit 234 to the extension base unit 248 in FIG. In addition, the current consumption of the FM amplifier 218 for outputting the video signal to the transmission line 235 is large, and further, the data signal ASK-modulated in the data signal transmission is mixed into the audio signal and becomes noise, resulting in call quality. There was a problem such as falling.

  The present invention is intended to solve the above-described conventional problems, and allows a video signal to be transmitted to an extension master without amplifying the video signal in the living room master, and the data signal is mixed into the audio. It is an object of the present invention to provide an intercom apparatus that can improve the call quality without doing so.

  The first aspect of the intercom apparatus of the present invention is that the visitor calls the resident with a call signal and makes a call with the resident, and makes a call with the visitor with a voice signal in response to the call from the entrance child machine. The main unit is connected to the main unit via a transmission line, and the video signal captured by the camera installed in the main unit is displayed on the monitor of the main unit, and the call signal and camera operation control are performed between the main unit and the main unit. In the interphone device that controls the transmission and reception of data signals such as signals, calls, telephone calls, video signals, etc., when connecting the main unit to the main unit via the extension transmission line via the main unit The living room master unit is provided with a branching transformer that is connected to the transmission line and transmits the video signal through the extension transmission line, and the entrance slave unit, the living room master unit, and the extension master unit are connected with the data signal as a video signal and an audio signal. Multiplexing Transmitting data signal line, characterized in that it comprises respective data transformer for balanced transmission on the extension transmission line.

  According to the intercom device of the present invention, it is possible to realize transmission of video signals at low cost by providing a branch transformer in the living room master unit, and to add a data transformer to the entrance slave unit, the living room master unit, and the extension master unit, respectively. By providing, it is possible to improve the call quality.

  Hereinafter, preferred embodiments of the intercom apparatus of the present invention will be described with reference to the drawings. In the present embodiment, operations such as a call by a normal visitor and a response by a resident are the same as in the prior art, and thus description thereof is omitted.

  FIG. 1 is a block diagram for explaining an intercom apparatus according to the present invention.

  In FIG. 1, the intercom apparatus of the present invention includes an entrance cordless handset 100, an in-room base phone 131, and an extension base phone 143. 143 is connected by an additional transmission line 145.

  The front door device 100 includes a camera 101, an FM modulation circuit 102, an FM amplifier 103, an LPF 104, and an FM / data transformer 105 as video signal transmission circuits. The data signal transmission circuit includes a CPU 106, an ASK modulation circuit 107, an LPF 108, an ASK demodulation circuit 109, a choke coil 112, a diode bridge 114, and a 2W-4W conversion circuit 113. The 2W-4W conversion circuit 113 is a microphone. , Connected to a call circuit comprising a speaker.

  Next, the living room master 131 includes a branch transformer 122, an FM amplifier 121, an FM demodulation circuit 120, a video amplifier 119, and a monitor 118, which are connected to the transmission line 144 and the additional transmission line 145, as video signal transmission circuits. As a data signal transmission circuit, a CPU 123, an ASK modulation circuit 124, an ASK demodulation circuit 125, an LPF 126, a transmission line 144, and a master data transformer 127 connected to the additional transmission line 145 and a choke coil 117 are provided. One choke coil 117 is connected to an impedance upper 116 and a 2W-4W conversion circuit 115 for preventing the impedance level from being lowered. The 2W-4W conversion circuit 115 is connected to a communication circuit including a microphone and a speaker. ing.

  Further, the extension base unit 143 includes an FM / data transformer 136, an FM amplifier 135, an FM demodulation circuit 134, a video amplifier 133, and a monitor 132 connected to the extension transmission line 145 as video signal transmission circuits. As a data signal transmission circuit, a CPU 137, an ASK modulation circuit 138, an ASK demodulation circuit 139, an LPF 140, and a choke coil 142 are provided. The choke coil 142 is connected to the additional transmission line 145 and also connected to the 2W-4W conversion circuit 141. The 2W-4W conversion circuit 141 is connected to a call circuit including a microphone and a speaker.

  Here, the operation of the intercom apparatus according to the present embodiment having the above-described configuration will be described.

  First, the operation of the video signal transmission circuit will be described. The video signal transmission circuit of the intercom apparatus of the present invention is the camera 101, the FM modulation circuit 102, the FM amplifier 103, the LPF 104, and FM / data in the entrance cordless handset 100 as described above. Transformer 105, branching transformer 122, FM amplifier 121, FM demodulation circuit 120, video amplifier 119, monitor 118, FM / data transformer 136, FM amplifier 135, FM demodulation circuit 134 in the extension master 143 , A video amplifier 133 and a monitor 132.

  In such a configuration, an image picked up by the camera 101 of the entrance cordless handset 100 is FM-modulated with a 12 MHz carrier by the FM modulation circuit 102 and then transmitted through the FM amplifier 103, the LPF 104, and the FM / data transformer 105. It is output to the line 144.

  The output video signal is branched by the branching transformer 122 of the living room main unit 131 via the transmission line 144 and is input to the FM amplifier 121 after being attenuated by about 13 dB. This signal is amplified by the FM amplifier 121, demodulated by the FM demodulation circuit 120, adjusted to an appropriate level by the video amplifier 119, input to the monitor 118, and displayed on the screen.

  On the other hand, the video signal on the transmission line 144 is branched by the branching transformer 122, attenuated by about 1 dB, and output to the additional transmission line 145. This video signal is sent to the extension master unit 143 via the extension transmission line 145, and sent to the monitor 132 via the FM / data transformer 136, the FM amplifier 135, the FM demodulation circuit 134, and the video amplifier 133 to display the screen. Is displayed.

  FIG. 2 shows an example in which a video signal is output from the entrance slave unit 100 to the living room master unit 131 and the extension master unit 143. The entrance slave unit 100, the room master unit 131, and the extension master unit 143 are connected by a bus. The video signal is transmitted from the entrance cordless handset 100 to the living room base unit 131 and is branched by the branching transformer 122 of the living room base unit 131 to be attenuated by about 13 dB, and the branched video signal is supplied to the additional base unit 143 by about 1 dB. This represents a situation in which transmission is performed with attenuation. The line loss at this time is 0.1 dB per meter. The circuit of the entrance cordless handset 100 is not shown.

  According to such a configuration, the branching transformer is provided in the living room master unit, so that the video signal is amplified by the living room parent unit and relayed to the extension parent unit, compared with the conventional method. This eliminates the need for FM amplifiers and LPFs that require a large amount of current consumption, making it possible to simplify the circuit configuration.

  Next, the operation of the data signal transmission circuit will be described.

  The data signal transmission circuit in the intercom apparatus of the present invention has been performing unbalanced transmission using a conventional 2W-4W conversion circuit for voice, whereas balanced transmission is performed using a transformer that shares both FM and data. It is characterized by that.

  First, in FIG. 1, the data signal output from the CPU 123 of the living room master 131 is ASK modulated by the ASK modulation circuit 124 with a 2 MHz carrier wave. In contrast to the 32 kHz carrier wave in the conventional system, the carrier frequency is increased to 2 MHz, so that the data communication speed can be improved by increasing the frequency (600 bps → 19.2 kbps), thereby making it possible to share the transformer. It has become. The data communication speed can be improved up to about 200 kbps.

The ASK-modulated data signal is output to the transmission line 144 via the LPF 126 and the master data transformer 127. The transmission line 144 has a high impedance at the frequency of the data signal and the video signal by the choke coil 117, thereby enabling the balanced transmission of the data signal while enabling the power supply from the living room base unit 131 to the entrance unit 100. It is said. However, the video signal transmission is terminated at 75Ω at both ends.
The data signal sent via the transmission line 144 is demodulated by the ASK demodulating circuit 109 via the FM / data transformer 105 and the LPF 108 of the entrance cordless handset 100 and input to the CPU 106.

  On the other hand, the data signal output via the master data transformer 127 is also output to the additional transmission line 145.

  In the data signal transmission from the office master 131 to the extension master 143, the data signal output to the extension transmission line 145 is demodulated by the ASK demodulator circuit 139 via the FM / data transformer 136 and the LPF 140 of the extension master 143. , Input to the CPU 137.

  The data signal is multiplexed and transmitted together with the audio signal and the video signal. FIG. 3 shows an example of the spectrum of multiplexed transmission in the intercom apparatus of the present invention. The frequency band in which each signal does not affect each other, for example, the audio signal is 0.2 to 10 kHz, the data signal Is divided into 2 MHz and the video signal is divided into 10 to 15 MHz, and these signals are multiplexed and transmitted.

  As described above, according to the intercom apparatus of the present invention, it is possible to transmit a video signal at a low cost by using a branching transformer as compared with the conventional system, and the size of the transformer and filter can be reduced by increasing the carrier frequency. And communication speed can be improved. Furthermore, by performing balanced transmission via the data signal transformer, it is possible to minimize the voice mixing of the data signal and improve the call quality.

It is a block diagram showing one Embodiment of a structure of each apparatus of the intercom apparatus of this invention. It is a figure showing the condition of attenuation | damping of the video signal in the intercom apparatus of this invention. It is a figure showing the example of the spectrum of the signal multiplexing in the intercom apparatus of this invention. It is a block diagram showing the structure of each apparatus of the conventional intercom apparatus.

Explanation of symbols

100: Entrance child machine 101: Camera 118 ... Monitor 122 ... Branch transformer 127 ... Master data transformer 131 ... Home parent Unit 143... Extension base unit 144... Transmission line 145... Extension transmission line

Claims (1)

An entrance cordless handset (100) in which a visitor calls a resident with a call signal and talks to the resident, and a room base phone (131) that talks with the visitor in an audio signal in response to a call from the entrance cordless handset Are connected by a transmission line (144), and the video signal captured by the camera (101) built in the entrance cordless handset is displayed on the monitor (118) of the base phone master, and the entrance cordless handset-the room parent In the intercom device for controlling the calling, calling, transmission of video signals, etc. by sending and receiving data signals such as the call signal and the camera operation control signal between machines,
In connecting the entrance cordless handset to the extension master unit (143) via the extension transmission line (145) via the extension master unit, the extension signal line connected to the transmission line is connected to the extension master line. While providing a branching transformer (122) for transmission via a transmission line,
In order to multiplex the data signal with the video signal and the audio signal, and to transmit the data signal on the transmission line and the additional transmission line in a balanced manner to the entrance slave unit, the living room master unit, and the extension master unit The interphone apparatus comprising the data transformers (105, 127, 136).

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