JPS639239A - Cordless telephone set - Google Patents

Abstract

PURPOSE:To facilitate and economize the installation by connecting one set of master set and plural slave sets each having its own individual selection signal correspondingly in radio waves, and selecting a slave set having the strongest electric field to use the plural slave sets. CONSTITUTION:In receiving a call signal A from an exchange detected by a call signal detector 21, a transmission radio wave B from a radio transmitter 2 of a master set 2 is sent. In such a case, an individual selection signal (ID signal) of each slave set is sent sequentially, a reception electric field D from a slave set started selectively is received by a radio receiver 26 and a control circuit 27 selects a slave set having an ID signal, e.g., ID1 having the strongest electric field. Then a bell ring signal E modulated by the ID1 signal is sent succeedingly and the bell of the slave set only is driven. The other slave sets are restored in a proper timing after receiving its own ID signal. If the received electric field is the same, a slave set with high priority is selected. Thus, the necessity of the provision of radio equipments in 1:1 correspondence is avoided and the connection with plural slave sets is attained at a low cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cordless telephone, and particularly to a cordless telephone in which one base unit is shared by a plurality of slave units.

[Conventional technology]

Conventionally, as shown in FIG. 4, a cordless telephone consists of a base unit 2 connected to an exchange 1 connected to a telephone line 11 via a subscriber line 12, and a slave unit 3 wirelessly connected to the base unit 2. are doing. That is, by wirelessly connecting the base unit 2 and the handset 3, the handset 3 is connected to the subscriber line 12 and the exchange 1 through the base unit 2, thereby making it possible to talk to a telephone (not shown).

[Problem that the invention seeks to solve]

In the conventional cordless telephone described above, base unit 2 and handset 3
Because there is a one-to-one wireless connection between the two, even though one phone requires two radios, one for the base unit and one for the slave unit, only one handset can be used. be. Therefore, when a plurality of slave units are required, base units and subscriber lines must be added correspondingly, making the equipment difficult and not economically effective.

In addition, since the cost of the wireless device accounts for a considerable portion of the total cost of the phone, it is not a good idea to have a one-to-one combination of base unit and slave unit, as one subscriber will be responsible for the cost of going wireless. isn't it.

[Means for solving problems]

In view of the above problems, the cordless telephone of the present invention makes it possible to use a plurality of handset units with one base unit, thereby simplifying the equipment and increasing economic efficiency.

The cordless telephone of the present invention connects one base unit and a plurality of handsets, each having a different individual selection signal, wirelessly, and the base unit sequentially transmits the individual selection signals with a time shift. In addition to receiving the individual selection signal of each slave unit transmitted in response to this individual selection signal, the electric field strength of this signal is compared to connect the slave unit with a strong electric field. It is composed of

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which an exchange 1 is connected to a telephone line 11, and a base unit 2 is connected to this via a subscriber line 12. This exchange 1 may be either a central exchange of a telephone office or a PABX, and the telephone line 1
It is connected to a higher order exchange (not shown) via 1. and,
The base unit 2 and a plurality of slave units 3 arranged correspondingly to the base unit 2
A wireless transmitter/receiver is disposed in each of a to 3n, and the base unit 2 and these slave units 33 to 3n are configured to be individually wirelessly connected.

The slave units 3a to 3n each receive a different individual selection signal (hereinafter referred to as
The base unit 2 has a function of transmitting a common ID signal to these slave units and receiving ID signals from these slave units.

Then, by receiving this, the ID signal can be confirmed, and a wireless connection can be established between the base unit and the slave unit. That is, the base unit transmits the ID signal of the slave unit sequentially at different times, and in response to this signal, receives the radio wave containing the ID signal of the slave unit transmitted from the slave unit, and detects and recognizes the radio wave. The strengths are compared, and a bell ringing signal is sent to the handset with the stronger stored electric field to notify the handset of the incoming call.

As shown in FIG. 2, the base unit 2 transmits and receives signals and audio signals to and from the exchange 1 through the subscriber line 12 through a 2-4 line conversion circuit 22, which includes a transmitting audio amplifier 23 and a receiving audio amplifier 25.
branch to 21 is a detector for detecting a calling signal from the exchange 1; The output signal of the transmission audio amplifier 23 is modulated by the wireless transmitter 24 and transmitted as a wireless signal.

Reference numeral 26 denotes a radio receiver, in which the radio waves received are demodulated, and the demodulated audio band signal is amplified by the reception audio amplifier 25. The transmitter 24 and receiver 26 are tuned to a defined radio channel by a local oscillator 28. 29 is a duplexer connected to the antenna 30. A control circuit 27 controls the transmission and reception of LD signals to and from the handsets 3a to 3n, and also performs various controls on other circuits.

According to this configuration, as shown in FIG. 3, when receiving a call signal A from the exchange 1 detected by the detector 21, the transmitter 24 is activated and sends out a transmission radio wave B. As a result, the slave units 3a to 3n are activated, and at this time, as the order of activation of the slave units, for example, as shown in the figure, the transmitting electric field C is set to ID, .
It transmits ID2...ID, l, compares the electric fields received from slave units selectively activated by this signal, and selects the slave unit with the strongest electric field. In this case, ID+
Assuming that the electric field of the slave unit having the signal is the strongest, the bell ringing signal E modulated by the IDI signal is then sent out, and only this slave unit rings the bell. The other handsets recover at an appropriate timing after receiving their own ID signal.

In this way, the parent 82 selects one from the plurality of slave units 3a to 3n, and if the received electric fields are the same, the priority is set in advance among the ID, ~ID, and signal. There is a way to select a child device with a higher priority. As a method of prioritizing, the handset that is most likely to be used may be given a higher priority, and the handset that is less frequently used may be given a lower priority.

It is also possible to manually switch this priority order on the base device. Furthermore, instead of the user manually setting the priority order, it is also possible to have the priority order automatically determined in the base unit.

〔Effect of the invention〕

As explained above, the present invention allows a single base unit to correspond to a plurality of slave units having different individual selection signals and connects them wirelessly, and also allows the slave units to communicate with each other without causing radio wave interference between these slave units. Since you can select one of them and use it by connecting it to the master unit, there is no need to install multiple master units for multiple slave units, which simplifies equipment and reduces costs. can be achieved and economically advantageous.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a circuit block diagram of a base unit, FIG. 3 is a signal time chart, and FIG. 4 is a conventional block diagram. 1...exchange machine, 2...w machine, 3.3a~3n...
Handset, 11... Telephone line, 12... Subscriber line, 21
...Call signal detector, 22...2-4 wire conversion circuit,
23... Transmission audio amplifier, 24... Wireless transmitter, 2
5... Receiving audio amplifier, 26... Wireless receiver, 27
...Control circuit, 28...Local oscillator, 29...Duplexer, 30...A1 i, , IF7

Claims (2)

[Claims] (1) A base unit and a plurality of slave units, each having a different individual selection signal, are associated and wirelessly connected, and the base unit is configured to be able to sequentially transmit the individual selection signals with a temporal shift. In addition, it is configured to receive the individual selection signal of each handset transmitted in response to this individual selection signal, and to compare the electric field strengths of these signals to establish a connection with the handset with a strong electric field. A cordless telephone featuring (2) A priority order corresponding to each child device is set in the base device, and when the electric field strength from each child device is equal, a child device is selected according to the priority order. Claim 1 Cordless telephone as described.