JPS63160425A - Cordless interphone - Google Patents

Abstract

PURPOSE:To listen to the voice of an opposite party without operating a talk switch at a called party by bringing the power supply of a reception circuit section into the applied state when a call tone sent from the opposed party is detected. CONSTITUTION:A call tone outputted from a call tone generating section 106 is set to a frequency higher than the audible frequency and a call tone sent from the opposite side is detected by a call tone detection circuit 102, then the detection signal is outputted to a control section B. The control section B is provided with an AND gate 3 inputting the detection signal from an intermittent pulse from an intermittent pulse generating section 105, a one-shot timer 110 is retriggered by the output and the output of one-shot timer 110 is inputted to an OR gate 2. Since a reception power supply control circuit 107 receives an intermitted pulse via the OR gate 2, a power supply is applied to a reception circuit section I from a power supply 109 and the reception circuit section I is operated always intermittently. Thus, even when no talk switch 12 is operated, the carrier signal and call signal of the opposite side are detected at the intermittent operation of the reception circuit section I.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention is particularly suitable for use in a loudspeaker type cordless intercom.

[Background technology]

This type of loudspeaker type cordless intercom is configured to transmit and receive different weak radio waves to enable mutual two-way calling and simultaneous conversation, and is used by installing it on a desk or the like. In order to improve the operational convenience of such a loudspeaker type cordless intercom, the present applicant proposed, in Japanese Patent Application No. 150599/1983, a system in which the talk switch and the call switch are made of the same switch! ! ! I devised a plan. However, in this proposal, the called party cannot hear the other party's real voice unless he or she operates the talk switch in order to answer the call after hearing the chime sound. .

[Purpose of the invention]

The present invention was developed in view of the above-mentioned circumstances, and an object of the present invention is to provide a cordless intercom that is convenient for operation and allows the called party to hear the other party's real voice without operating the talk switch. It is said that

[Disclosure of the invention]

The present invention proposed to achieve the above object includes an intermittent pulse generating section that outputs a pulse signal that drives a receiving circuit section at predetermined time intervals, and transmits and receives radio wave signals of different frequencies. This is an improvement of a cordless intercom that enables two-way calling and simultaneous talking, and in particular sets the ringing tone output from the ringing tone generator included in the transmitting circuit to a higher frequency than the audible frequency, and also a timer circuit that is retriggered by a pulse signal output from the intermittent pulse generator when a ring tone detection circuit included in the reception circuit detects a ring tone; It is characterized by comprising a control section that maintains the drive state.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an external configuration diagram of a cordless intercom of the present invention.

As shown in the figure, the cordless intercom A has an antenna 11 installed on a main body 10 installed on a desk or the like, and a talk switch 12. The configuration includes a microphone 13 and a speaker 14. Reference numeral 15 denotes a call indicator light that lights up during a call, and when calling the other party's cordless intercom, the user can operate the talk switch 12 and utter his/her real voice directly into the microphone 13 to call the other party.

The called party can talk to each other at the same time by operating the talk switch 12 of the cordless intercom of the loudspeaker type having the same configuration as shown in FIG. 1 and speaking directly into the microphone 13.

FIG. 2 shows a block diagram configuring the main parts of the cordless intercom of the present invention.

As shown in the figure, the cordless intercom of the present invention includes a speaker SP, an amplifier AMP, and a demodulation circuit.

A receiving circuit section I that combines a mixer and RF-AMP, a microphone MIC, an amplifier AMP, and a modulation circuit.

The 0 oscillation circuit 100, which is configured with a transmitting circuit section (2) combining RF-AMP and a power supply control section, outputs a high-frequency signal of a predetermined frequency as a carrier signal.
After being modulated with a human-powered audio signal from the IG, it is transmitted as a radio wave signal from the antenna 11 via a duplexer. Further, a radio wave signal transmitted from the cordless intercom l of the other party is captured by the antenna 11, inputted to the receiving circuit section I, demodulated, and then outputted as an audio signal from the speaker SP.

The talk switch 12 is a so-called one-shot pushbutton switch, and when it is operated, a timer T1 is set. Therefore, the timer TI is configured to be set at the rising edge of the input signal. OR gate 1
The output of the talk switch 12 and the timer Tl ()
- After operating the switch, the transmitter/receiver circuit 1. The OR gate 2 receives the pulse signal intermittently generated from the intermittent pulse generator 105 and the output of the OR gate 3. , its output serves as an activation signal for the receiving power supply control circuit 107. Also, OR gate 3 has OR gate 1. The output of OR gate 4 is input. The output of this OR gate 3 serves as an activation signal for the transmission power supply control circuit 108.

The receiving circuit section I and the transmitting circuit section (2) include the above-mentioned receiving power supply control circuit 107. The transmission power supply control circuit 108 operates and the power m1o
It is operated by supplying power from 9.

On the other hand, the AND gate 1 inputs the output of the OR gate 1 and the output of a NOT gate that inverts the output of the carrier detection circuit 101, and operates the ring tone generating section 106 by the AND output of the two. Therefore, the calling tone generating section 106 is activated when the talk switch 12 is operated and for the set time τ1 of the timer Tl without detecting a carrier signal, and the calling tone is sent to the transmitting circuit section (2).

Here, in the present invention, the ringing tone output from the ringing tone generating section 106 has a frequency higher than the audible frequency (
The signal is set to have a frequency of at least lokHz or more.

Furthermore, the AND gate 2 generates an operation sound generator 10 by logical product of the output of the talk switch 12 and the output of the NOT gate.
4, the talk switch 12 is operated and the operation sound is output from the speaker sp only when the carrier signal is not detected.

Further, the receiving circuit section I is provided with a calling tone detection circuit 102, and when the calling tone transmitted from the other party is detected by this circuit 102, the detection signal is transmitted to the control section B.
Send to.

Here, the control unit B is provided with an AND gate 3 that manually inputs the detection signal from the ringing tone detection circuit 102 and the intermittent pulse from the intermittent pulse generation unit 105, and the AND gate 3
The one-shot timer 11O is retriggered by the output of the one-shot timer 110, and the output of the one-shot timer 110 is manually input to the OR gate 2.

In a cordless intercom with this configuration,
Since the receiving power supply control circuit] 07 inputs the intermittent pulse output from the intermittent pulse generating section 105 via the OR gate 2, power is supplied from the power supply 109 to the receiving circuit section ■, and the receiving circuit section ■ is operated intermittently. Therefore, even when the talk switch 12 is not operated, the receiving circuit section ■
During intermittent operation, carrier signals and calling signals from the other party can be detected.

Next, with reference to FIG. 2, an explanation will be given of the operation when two-way simultaneous calls are made between the loudspeaker type cordless intercoms.

On the calling side, one-shot operation of the talk switch 12 activates the transmitting and receiving circuit sections I and (2).

At this time, there is no carrier signal, so the AND game)
1. The output of AND gate 2 is sent to ring tone generator 106.
The at sound generating unit 104 is activated, a calling tone is transmitted from the antenna 11 via the transmitting circuit unit I, and at the same time, an operation sound is output from the speaker SP. Talk switch 12
Since the timer T1 is clocked when the timer TI is operated, the transmission and reception circuit sections 1. (2) Power on is maintained and the output of the ringing tone is maintained.

On the other hand, on the called side, the intermittent pulse generator 105 generates a signal from the receiving circuit! Since the call tone detection circuit 102 of the receiving circuit section I detects the call tone transmitted from the calling side, the call tone detection circuit 102 of the receiving circuit section I detects the call tone transmitted from the calling side. When a ring tone is detected,
The detection signal is sent to the control section B, and the following operations are performed.

That is, when the ring tone detection circuit 102 outputs a detection signal, this detection signal is input to the AND gate 3, so the AND gate 3 performs a logical product of this detection signal and the intermittent pulse output from the intermittent pulse generation section 105. An output is obtained, and this output pulse is input as a trigger pulse to the one-shot timer 110, and is input to the OR gate 2 to activate the receiver power supply control circuit 107, and the receiver circuit section! Turn on the power. Here, one shot timer 110
Since the set time t3 is set to a time slightly larger than the time interval τ2 of the intermittent pulse, retriggering is performed every time a pulse signal is output from the AND gate 3. As a result, the intermittent pulse generator 105 When an intermittent pulse is output from the receiving circuit section I, the power to the receiving circuit section I is turned on, and the ring tone detection circuit 102 is activated to detect the calling tone of the other party, the power to the receiving circuit section I is maintained. At this time, the real voice generated by the other party toward the microphone MIC will be output as is from the speaker SP.

When the called party confirms this real voice and operates the talk switch 12 in one shot to make a call, this operation activates the above-mentioned timer T1, and the OR gate 1. Since the output of the timer TI is input to the OR gate 2 via the OR gate 3, an operating signal is continuously sent to the reception power supply control circuit 107 during the set time τ1 of the timer T1, and at the same time the transmission power supply control circuit 107 is continuously sent. An activation signal is also sent to the circuit 108, and the power supply to the receiving circuit section I and the transmitting circuit section (2) is maintained, making it possible to talk simultaneously.

Note that when the talk switch 12 is operated to make such a call and during the set time τ1 of the timer Tl, the carrier detection circuit 101 of the receiving circuit section I on the called side does not detect the carrier signal sent from the calling side. Since it is detected, A
There is no output from NDI and AND2, so no ringing tone is generated, and generation of operation sounds is also prohibited.

Then, when the calling tone from the other party stops, the intermittent pulse output from the intermittent pulse generator 105 immediately before the calling tone stops becomes the last trigger signal for the one-sit timer 110, so the one-sit timer 1
10 inputs the output to the OR gate 2 only during the set time τ3 after the manual input of the trigger signal, and still inputs the output to the receiving power supply control circuit 1.
07 is activated and the receiving circuit section! It is possible to maintain the power supply to the terminals, and at this time, it is possible to talk to each other at the same time.

Note that timer T2 prohibits power cut-off for a set time τ4 when the carrier is interrupted for some reason during a call. After the set time τ4 has elapsed, it is determined that the call has ended and a reset signal is sent to timer TI. The structure is designed to suppress power consumption as much as possible.

The operation of each part <a> to (f) in FIG. 2 will be explained with reference to FIGS. 3(a) to 3(f).

〔Effect of the invention〕

As can be understood from the above explanation, according to the cordless intercom of the present invention, when a calling tone transmitted from the other party is detected, the power of the receiving circuit section (■) is kept on, so that the other party makes a sound into the microphone. Since the user's real voice can be heard without holding the talk switch, it is extremely convenient to be able to hear the requirements of the other party even when the cordless intercom cannot be operated.

[Brief explanation of the drawing]

FIG. 1 is a side view of the external configuration of a cordless intercom to which the present invention is applied, and FIG. 2 is a schematic configuration diagram of the main circuit of the present invention.
FIG. 3 is an explanatory diagram of the operation of parts (a) to (f) in FIG. 2. (Explanation of symbols) A: Cordless intercom of the present invention B: Control section ■: Receiving circuit section ■: Transmitting circuit section 105: Intermittent pulse generating section 106: Ringing tone generating section

Claims (2)

[Claims] (1) Equipped with an intermittent pulse generator that outputs a pulse signal that drives the receiving circuit at a predetermined time interval,
In cordless intercoms that enable two-way calling and simultaneous talking by transmitting and receiving radio signals of different frequencies, the ringing tone output from the ringing tone generator included in the transmitting circuit is set to a higher frequency than the audible frequency. It also has a timer circuit that is retriggered by a pulse signal output from the intermittent pulse generator when the ring tone detection circuit included in the reception circuit detects a ring tone, and the output of the timer circuit A cordless intercom characterized by comprising a control section that maintains the receiving circuit section in a driving state. (2) The cordless intercom according to claim 1, wherein the cordless intercom is of a loudspeaker type.