JPH02250556A - Handset device for bidirectional simultaneous calling - Google Patents

Abstract

PURPOSE:To attain the bidirectional and simultaneous calling without causing any howling to make each electroacoustic transducer serve as a speaker and a microphone at one time. CONSTITUTION:The electrical speech receiving signals are applied between the pairs of speech receiving signal input terminals 16A/16B and 26A/26B containing the balanced bridge circuits 15 and 25 connected with the electroacousitic transducers 11 and 21 having the reversible electroacoustic transducing functions through a single side of each balanced bridge circuit. Then these electrical speech receiving signals are converted into the acoustic signals by the transducers 11 and 21. Then the electrical speech sending signals are converted from the acoustic speech sending signals via the transducers 11 and 21 and obtained between the pairs of speech sending signal output terminals 17A/17B and 27A/27B. As a result, it is not required to prepare a speech sending microphone and a speech receiving speaker independently of each other. Thus a single electroacoustic transducer can perform the bidirectional and simultaneous calling without causing any howling.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a transmitting/receiving device for simultaneous two-way communication such as a telephone or an intercom.

B. Summary of the Invention The present invention provides a bridge circuit that satisfies a balance condition in which an electroacoustic transducer having a reversible electroacoustic conversion function is connected to one side, and a pair of received signal input terminals to which an electrical received signal is supplied; By providing a pair of transmitting signal output terminals for extracting the electrical transmitting signal converted by the electroacoustic transducer, a transmitting/receiving device capable of simultaneous two-way conversation is realized using - electroacoustic transducers. It is something.

C. Conventional technology In general, telephones, intercoms, etc. are equipped with separate microphones for transmitting and speakers for receiving calls in order to achieve a two-way simultaneous conversation function that allows both transmitting and receiving calls at the same time. ing.

In addition, in simple intercoms, door phones, transceivers, etc., a conversion unit with a reversible electroacoustic conversion function, such as a dynamic speaker or a condenser microphone, is used to convert the conversion unit between when transmitting and when receiving a call. There have been provided devices that perform two-way communication using a relay communication method such as the so-called BreathTalk method, in which the connection is changed over with a switch.

D. Problems to be Solved by the Invention As mentioned above, telephones, intercoms, etc. that perform two-way simultaneous calls not only need to be equipped with separate microphones for transmitting and speakers for receiving calls, but also the output from the speaker for receiving calls. The acoustic signal transmitted by the user is converted into an electrical signal by the transmitting microphone and transmitted, and there is a risk of causing acoustic oscillation, so-called howling, and the howling makes it impossible to make a good call. There was a problem.

Therefore, the present invention aims to solve the above-mentioned conventional problems in telephones, intercoms, etc. that perform simultaneous two-way calls, and has developed a new system that enables simultaneous two-way calls using - electroacoustic transducers. The present invention provides a transmitting/receiving device for simultaneous two-way communication having a configuration of:

In order to achieve the above-mentioned object, the transmitting/receiving device for two-way simultaneous calls according to the present invention includes a bridge circuit that satisfies a balance condition in which an electroacoustic transducer having a reversible electroacoustic conversion function is connected to one side. It is characterized in that it is provided with a pair of reception signal input terminals to which an electrical reception signal is supplied, and a pair of transmission signal output terminals from which an electrical transmission signal converted by the electroacoustic transducer is taken out.

F-effect In the transmitting/receiving device for two-way simultaneous conversation according to the present invention, electricity is applied between a pair of reception signal input terminals provided in a bridge circuit in which an electroacoustic transducer having a reversible electroacoustic conversion function is connected on one side. The received signal is converted into an acoustic signal by the electroacoustic transducer, and the electrical transmission signal obtained by converting the acoustic transmission signal by the electroacoustic transducer is sent to the transmission signal output terminal pair. obtained in between.

Eel! Means for Solving the Problem G. Embodiment Hereinafter, an embodiment of the transmitting/receiving device for two-way simultaneous communication according to the present invention will be described in detail with reference to the drawings.

The embodiment shown in FIG. 1 is a pair of transmitting and receiving devices (10).

(20) The present invention is applied to an intercom for simultaneous two-way communication.

The transmitter/receiver (lO) has a bridge circuit (15) connected to the electroacoustic transducer (11) on the negative side, a pair of receive signal input terminals (16A) and (16B), and a transmit signal output terminal (
17A) and (178) pairs.

The bridge circuit (15) includes the electroacoustic transducer (1
1) and the impedance Z of the electroacoustic transducer (11)
Impeder 7 equivalent to 11 characteristics Z+t(Z+g=Z
++) characteristic, and two resistors (13) and (14) having mutually equal resistance values R+++R1□ (Rat-Rat), Z+t ・Rz −Zl!・Rat The equilibrium condition is satisfied.

As the electroacoustic transducer (11), one having a reversible electroacoustic conversion function, such as a dynamic speaker or a condenser microphone, is used.

Further, as the circuit element (12), the same electroacoustic transducer as the electroacoustic transducer (11) may be used by storing and sealing it in a small container.
Frequency Depe.
ndent Negative Re5istance
) circuit elements can be used.

In the transmitting/receiving device (10) having such a configuration, when a receiving signal voltage is applied between the pair of receiving signal input terminals (16A) and (16B), the electricity provided on the - side of the bridge circuit (15) is A signal current corresponding to the reception signal voltage flows through the acoustic transducer (11), and the electrical reception signal is converted into an acoustic reception signal by the electroacoustic transducer (11) and output. Since the bridge circuit (15) has a configuration that satisfies the equilibrium condition, the receive signal voltage applied between the pair of receive signal input terminals (16^) and (16B) causes the transmit signal output terminal (17 ^), (17
B) No potential difference is created between the pair.

However, the acoustic transmission signal is transmitted through the electroacoustic transducer (1).
1), the balance of the bridge circuit (15) is disrupted by the amount of the acoustic transmission signal that is converted into an electrical transmission signal by the electroacoustic transducer (11), and the electric The electrical transmission signal voltage converted by the acoustic converter (11) is transmitted to the transmission signal output terminals (17A) and (17B).
Obtained between pairs.

That is, the electroacoustic transducer (11) provided on the negative side of the bridge circuit (15) is connected to the received signal input terminal (
16A), (16B) It functions as a speaker that converts the electrical reception signal given to the pair into an acoustic reception signal output, and at the same time converts the acoustic transmission signal given by the caller into an electrical transmission signal. It functions as a microphone which converts the signal and outputs it from the pair of transmitting signal output terminals (17A) and (17B).

Further, the above-mentioned transmitting and receiving device (20) includes the above-mentioned transmitting and receiving device (20).
0), an electroacoustic transducer (21) having a reversible electroacoustic conversion function, a circuit element (22) having an impedance characteristic equivalent to that of the electroacoustic transducer (21), and a circuit element (22) having an equal resistance value. Equipped with a bridge circuit (15) that satisfies a balanced condition and is configured by two resistors (23) and (24), and the balanced bridge circuit (25) is connected to a pair of receive signal input terminals (26A) and (26B) and a pair of transmit signals. Signal output terminal (2
7^), (27B) pairs are provided, and the electroacoustic transducer (21) functions as a speaker and a microphone at the same time.

Then, the reception signal input terminal (
16A) and (16B), the above-mentioned transmitting/receiving device (2
0) (7) Transmission signal output terminal (27A), (27B
) pairs are connected via the amplifier (1), and the reception signal input terminals (26^) and (26
A pair of transmitting signal output terminals (17A) and (17B) of the transmitting and receiving device (10) is connected to the pair B) via an amplifier (2).

In an intercom with such a configuration, the above-mentioned transmitting/receiving device (
10), each electroacoustic transducer (11) of (20),
(21) serve as both a speaker and a microphone at the same time, so simultaneous two-way communication can be performed without feedback.

In addition, although the present invention was applied to an intercom in the above-mentioned repair example, the present invention is not limited to the above-mentioned embodiment (and can be applied to various two-way simultaneous call systems such as hands-free telephones and voice conference systems). Needless to say, it can be applied to.

H Effects of the Invention In the transmitting/receiving device for two-way simultaneous conversation according to the present invention, a pair of reception signal input terminals provided in a balanced bridge circuit in which an electroacoustic transducer having a reversible electroacoustic conversion function is connected on one side. The applied electrical reception signal is converted into an acoustic signal by the electroacoustic converter, and the electrical transmission signal obtained by converting the acoustic transmission signal by the electroacoustic converter is output as a transmission signal. Since it can be used between a pair of terminals, there is no need to separately provide a microphone for sending and a speaker for receiving.
Electric sounds! ! The II converter allows simultaneous two-way communication without the risk of howling.

FIG.

(10), (20n ・ ・ ・ ・ ・ ・
・ ・ ・ ・ ・ ・ ・ ・ (11), (2
1) ・・・・・・・・・・・・・・・・・・(15)
, (25) ・・・・・・・・・・・・・・・
・(16A), (16B), (26A), (26B)
...(17^), (17B), (27A)
, (27B) ... Transceiver device electroacoustic transducer bridge circuit Receiving signal input terminal Transmitting signal output terminal

Claims (1)

[Claims] A bridge circuit that satisfies the equilibrium condition, in which an electroacoustic transducer having a reversible electroacoustic conversion function is connected to one side, includes a pair of received signal input terminals to which an electrical received signal is supplied, and a received signal input terminal pair that is converted by the electroacoustic transducer. 1. A transmitting/receiving device for simultaneous two-way communication, characterized in that it is provided with a pair of transmitting signal output terminals for extracting an electrical transmitting signal.