JP2980963B2 - Door phone cord - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a door phone handset to which a noise suppression function is added.

[Conventional technology]

FIG. 3 is a view showing the external appearance of the door phone slave 1 and the parent device 2. In general, the door phone slave 1 is installed at the entrance of a house, and the master device 2 is installed in a living room or the like in a house. , intercom slave unit 1 and the base unit device 2 is connected by electrical lines W _1, W _2.

Door phone handset 1 is a microphone equivalent to at least a transmitter
Provided with a speaker R ₁ corresponding to M ₁ and the receiver, visitors are provided with push button switch S ₁ and the like for notifying that it has visited against residents. The base unit device 2 at least provided with a microphone M ₂ and speaker R ₂ corresponding to the receiver corresponding to the transmitter, the push button switch S doorphone slave unit 1 to indicate that the visitor has visited against residents ₁
It has and acoustic part O ₂ to sound the alarm sound, and become the exclusive master unit device 2 is also a security function of disaster prevention crime prevention, such as in the house when you press.

Thus, the visitor presses the push button switch S ₁ of the intercom slave unit 1, the acoustic portion O ₂ of the main terminal device 2 sounding an alarm sound of that there is a visitor against residents. Residents know that there is in the visitor in the notification sound is, can talk to the front door of the visitor through the microphone M ₂ and speaker R ₂ of the handset 3 taking the handset 3 of the master unit device 2, The visitor can talk to the resident through the microphone M ₁ and the speaker R ₁ of the door phone handset 1.

Figure 2 is a circuit block diagram showing a main portion of a conventional speech circuit doorphone slave unit 1 and master unit device 2, intercom slave unit 1 have a wire line connection terminals T ₁ and the wire line connection ground terminal T ₃ and, also, the master unit device 2 has a wire line connection terminals T ₂ and the wire line connection ground terminal T _4. Wire line connection terminals T ₁ and master unit device electrical line connection terminal T ₂ of the second intercom slave unit 1 is connected via electric lines W _1, the electric wire path of the intercom slave unit 1 connected ground terminal T ₃ and base unit device The electric wire connection ground terminal T ₄ is the electric wire W ₂
Connected through.

The internal circuit of the intercom slave unit 1, the output of the microphone M ₁ is connected to the transmission amplifier circuit E _1, the output of the transmitter amplifier circuit E ₁ is substantially 5M
In Hz of frequency is connected to the modulation circuit F ₁ for modulating a sound signal,
The output of the modulation circuit F ₁ is connected to a wire line connection terminals T _1. Also, the speaker R ₁ is connected to the output of the receiving amplifier circuit A ₁ ,
Receiving amplifier A ₁ is connected to the output of the demodulation circuit B _1, a demodulation circuit B ₁ represents is connected to the output of the band filter circuit C ₁ which is a center frequency substantially 6 MHz, the input of the band filter circuit C ₁ is the wire line connection It is connected to the terminal T _1.

In the internal circuit of the main terminal device 2, the output of the microphone M ₂ is connected to the transmission amplifier circuit E _2, the output of the transmitter amplifier circuit E ₂ is connected to the modulation circuit F ₂ which modulates a sound signal at a frequency of approximately 6MHz the output of the modulation circuit F ₂ is connected to a wire line connection terminal T _2. Also,
Speaker R ₂ is connected to the output of the receiving amplifier A _2, reception amplifying circuit A ₂ is connected to the output of the demodulation circuit B _2, demodulation circuit B ₂
It is connected to the output of the band filter circuit C ₂ which is a center frequency substantially 5 MHz, input bandwidth filter circuit C ₂ is connected to a wire line connection terminal T _2.

Therefore, a call between the conventional intercom slave 1 and the base unit 2 is performed as follows.

Voice visitors are transmitting amplifier circuit as a sound signal is picked up from the microphone M ₁ with noise 1 around intercom slave unit
It is output to the E _1. Amplified sound signal from the microphone amplifier circuit E ₁ is modulated by the modulation circuit F ₁ for modulating a sound signal at a frequency of approximately 5MHz is output to the wire line connection terminals T _1.

Therefore, the electrical lines connecting terminal T ₂ of the electrical lines W ₁ master unit device connected via the 2, modulated modulated signal is inputted in the modulation circuit F ₁ for modulating a sound signal at a frequency of approximately 5 MHz, the input of the band filter circuit C _2. Band filter circuit C ₂ is approximately 5M
Since the center frequency is set to Hz, the band-pass filter circuit C ₂ discriminates only the output of the modulation circuit F ₁ that modulates the sound signal picked up from the microphone M ₁ of the door phone slave device 1 and demodulates the demodulation circuit B ₂
Output to Demodulation circuit B ₂ is receiving amplifier A ₂ demodulates the sound signal picked up from the microphone M ₂ doorphone slave unit 1
Output to, receiving amplifier A ₂ drives the speaker R _2.
And, residents can listen to the voice of the visitor from the speaker R _2.

Meanwhile, residents of speech is output to the transmission amplifier circuit E ₂ as a sound signal is picked up from the microphone M _2. Transmission amplifier circuit
Amplified sound signal from the E ₂ is modulated by the modulation circuit F ₂ which modulates a sound signal at a frequency of approximately 6MHz is output to the wire line connection terminal T _2.

Therefore, the intercom slave unit are connected via electric lines W ₁ 1
The electrical line connection terminals T _1, is input modulated signal modulated by the modulation circuit F ₂ which modulates a sound signal at a frequency of approximately 6 MHz, the input of the band filter circuit C _1. Since the band filter circuit C ₁ has a center frequency substantially 6 MHz, the band filter circuit
C ₁ discriminates only the output of the modulation circuit F ₂ that modulates the sound signal picked up from the microphone M ₂ of the master device 2 and demodulates the demodulation circuit B ₁
Output to The demodulation circuit B ₁ demodulates the sound signal picked up from the microphone M ₂ of the master device 2 and outputs the demodulated signal to the reception amplification circuit A _{1. The} reception amplification circuit A ₁ drives the speaker R ₁ . In this way, visitors can listen to the voice of the residents from the speaker R _1.

In this way, the visitor and the resident can talk.

[Problems to be solved by the invention]

By the way, when the noise around the door phone slave 1 is large, for example, when the entrance faces the road, it is difficult for the resident to hear the voice of the visitor. However, the volume with the sensitivity and the amplification factor of the transmission amplifier circuit E ₁ microphone M ₁ doorphone slave unit is fixed, in two stages sound microphone M ₁ doorphone slave unit has picked up the base unit device 2 Adjust the speaker
Only has volume control which can drive the R ₂ (not shown), can not be finely adjusted to the most audible likely volume. In addition, even if there is a volume control unit that can be finely adjusted, the resident manually adjusts the volume control unit of the base unit 2 to the optimum volume every moment according to the noise around the door phone handset 1 that changes every moment. There was a problem that it was troublesome to do.

The present invention has been made in order to improve the above-mentioned problems, and an object of the present invention is to make it possible for a resident to use a hand-held device at every moment according to the noise around a door phone handset, which is constantly changing. It is an object of the present invention to provide a door phone handset that enables a resident to listen to a visitor's voice at an optimum volume without adjusting the volume control unit of the parent device to the volume.

[Means for solving the problem]

The present invention, in order to solve the above problems, at least,
A base unit which includes a transmitter, a transmission amplifier circuit for amplifying a sound signal from the transmitter, and a receiver and a receiver amplifier circuit for driving the receiver, and which is connected to the base unit via an electric wire and connected to the base unit In the intercom handset that can communicate with each other, an amplification control input unit for controlling the amplification factor of the transmission amplification circuit is provided in the transmission amplification circuit, and the audio of the sound signal from the transmission device is provided. A noise level detection circuit for outputting an output according to the noise level ratio is provided, an output of the noise level detection circuit is connected to the amplification rate control input section, and a sound-to-noise level ratio of a sound signal from the handset is small. In some cases, the amplification factor is increased.

[Action]

With the above configuration, when the ratio of the visitor's voice picked up from the handset of the door phone handset to the noise around the door phone handset is small, the amplification factor of the transmission amplifier circuit is increased. The sound picked up from the handset of the handset is output at a large volume from the base unit.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG.

FIG. 1 is a circuit block diagram showing a main part of a communication circuit of the intercom slave unit 1 according to the present invention (however, the communication circuit of the base unit 2 is the same as the conventional example, so that detailed illustration is omitted. The following points are different from the conventional example.

In other words, by providing the gain control input 4 for controlling the amplification factor of itself in transmission amplifying circuit E _1, and the voice S visitors among the picked-up sound from the microphone M ₁ doorphone slave unit 1 and the volume ratio of the noise N of the surrounding intercom slave unit 1 (referred to as S / N ratio) providing the noise level detecting circuit D ₁ to the output in response to, and the noise level detection output of the microphone M ₁ by connecting the output of the noise level detecting circuit D ₁ to the amplification factor control input unit 4 while connected to the circuit D _1, when the S / N ratio of the picked-up sound from the microphone M ₁ is small, transmission amplifying circuit E ₁ is to increase the amplification factor.

Therefore, a visitor visits the front door, and the intercom 1
And when the visitor and residents between the base unit device 2 is a call, the greater the noise, such as automobile facing the front door is a road that the S / N ratio of the picked-up sound from the microphone M ₁ is small the senses the noise level detecting circuit D ₁ inputs an output corresponding to the S / N ratio in the gain control input 4 increase the amplification factor of the transmission amplifier circuit E _1. Since it is, the sound signal picked up from the microphone M ₁ is input is amplified by the transmission amplifier circuit E ₁ at a high amplification factor than if the S / N ratio is large modulation circuit F _1.

Optional therefore (output of the modulation circuit F ₁ after this is, from the speaker R ₂ of the main terminal device 2, the paths and operations are output as sound by the microphone M ₁ is picked up is the same as that described in the prior art ), The resident is the speaker of the base unit 2
From R _2, than when the S / N ratio is large at high volume, it is possible to listen to the sound picked up from the microphone M _1.

On the other hand, if there is no quiet noise doorstep, a greater S / N ratio of the picked-up sound from the microphone M _1, an output noise level detecting circuit D ₁ is in accordance with the S / N ratio by detecting amplified enter the rate control input 4 lowers the amplification factor of the transmission amplifier circuit E _1. Since it is, the sound signal picked up from the microphone M ₁ is input is amplified by the transmission amplifier circuit E ₁ at a low amplification factor than if the S / N ratio is small modulation circuit F _1. The inhabitants from the speaker R ₂ of the main terminal device 2, than when the S / N ratio is small with a small volume, it is possible to listen to the sound picked up from the microphone M _1.

By the way, when the S / N ratio is large, there is no noise and the sound is quiet. Therefore, even if the resident listens to the sound picked up from the microphone M ₁ with a small volume from the speaker R _{2 of the base} unit 2, the resident can talk about the visitor. You can listen to

〔The invention's effect〕

Since the door phone handset of the present invention is configured as described above, in response to the noise around the door phone handset that changes every moment, the resident can manually adjust the volume of the master unit to the optimum volume every moment. This makes it possible to provide a door phone handset that allows the resident to listen to the visitor's pitch at an optimum volume without adjusting the pitch.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a main part of a communication circuit showing an embodiment of a door phone handset according to the present invention, and FIG. 2 is a circuit showing a main part of a communication circuit of a conventional door phone handset and a base unit. FIG. 3 is a front view of the intercom slave unit and the parent device. 1 door phone handset, 2 base unit, 4 amplification factor control input section, A ₁ reception amplification circuit, D ₁ noise level detection circuit, E ₁ transmission amplification circuit, M ₁ … transmitter, R ₁ … receiver, W ₁ , W ₂ … electric line.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) H04B 1/02-1/04 H03G 3/20-3/34 H04M 1/02-1/23 H04M 9 / 00-9/10

Claims (1)

(57) [Claims] At least a transmitter, a transmitter amplifier circuit for amplifying a sound signal from the transmitter, a receiver and a receiver amplifier circuit for driving the receiver are provided. In the intercom slave unit which can be connected to and communicate with the parent device, the transmission amplification circuit is provided with an amplification factor control input unit for controlling the amplification factor of the transmission amplification circuit, and the transmission device A noise level detection circuit for outputting an output according to the level ratio between the sound of the sound signal and the noise of the sound signal, and connecting the output of the noise level detection circuit to the amplification rate control input section; A door phone slave unit characterized in that the amplification factor is increased when the level ratio between noise and noise is small.