JPH0378333A - Cordless telephone system - Google Patents

Abstract

PURPOSE:To easily attain transmission/reception between a master unit and slave units by providing a means detecting a transmission level, enabling the radio transmitter of the salve units to be transmitted and muting reception signals and a means detecting a reception signal level ad stopping the radio transmitters of the slave units for respective slave units. CONSTITUTION:Reception level detectors 44a and 44b detect the signal levels of receivers 45a and 45b in the slave units 2a and 2b. When the signal levels are large, transmission signal attenuators 49a and 49b are operated and the passage of the signals of the transmitters 50a and 50b is suppressed. Transmission level detectors 48a and 48b detect the signal levels of transmitters 50a and 50b. When they are large, reception signal attenuators 43a and 43b are activated and the passage of the signals is suppressed. The frequency of a radio wave emitted from the master unit 1 is f1, and the frequency of the radio wave emitted from the slave units 2a and 2b is f2. Thus, transmission/reception between the master unit 1 and the slave units 2a and 2b is attained by providing a pair of a radio transmitter 33 and a radio receiver 35 in the master unit 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a cordless telephone device. The present invention relates to a cordless telephone device having a plurality of handsets, in which a call can be made between one handset and another handset.

(Prior Art) Conventionally, a device shown in FIG. 2 has been used as this type of cordless telephone device.

In the figure, 1 is a parent device, and 2a and 2b are slave devices. First, the parent device will be explained. 11 is a line relay, 12 is a 2-wire/4-wire conversion circuit, 13.13' is an extension relay, and 15.15 is a line relay. ' is a radio transmitter, 16.16' is a radio receiver, 17.17° is a transmitting antenna, and 18 and 18' are receiving antennas.

Next, the slave units 2a and 2b will be explained.

21b is a receiving antenna, 22a and 22b are transmitting antennas, 23a and 23b are radio receivers, 24a and 24b are radio transmitters, 25a and 25b are receivers, and 26a and 26b are transmitters, where r la+ f ta+ f
lb+f*b indicates the frequency of the radio wave.

Next, the operation will be explained. (1) When connecting the handset 2a to the telephone line In this case, the wireless transmitter 15. of the wireless transmitter and the wireless receiver. Wireless receiver 16. Wireless receiver 23a.

Wireless transmission v! 24a becomes operational, and the wireless transmitter 15
The wireless receiver 16, the wireless receiver 23b, and the wireless transmitter 24b become inactive. Still line relay 1
1 is closed.

The call route is as follows.

For transmitting: 26 a -+24 a -+22 a
-+ f za-+18-16→13゛→12→11
→Calls are sent via telephone line.

For receiving calls: Telephone line → 11 → 12 → 13 → 15 → 17
→f 1m-+21 a -+23 a -+25 a
The call is received by

(I[) In the case of extension call connection between handset 2a and handset 2b In this case, the wireless transmitter and wireless receiver are all in the operating state, the line relay 11 is open, and the extension relay 13
and 13° switches the radio transmitter 15″ and radio receiver 16° polarization.

The call is made as follows.

(i) When transmitting a call from handset 2a 26 a-243-+'l'l B -+ f t, -
+13-+15-+13'-+15'→17' →
f0 → 21b → 23b → 25b When sending a call from 6D handset 2b 26b → 24b → 22b → fth → 181 → 16" → 1
3 → Eng 5 → 17 → f +a → 21 a -+23 B
-+25 a (III) When connecting handset 2b to a telephone line This case is almost the same as (1) above, but in this case, wireless connection is possible without using the wireless transmitter 15゛ and the wireless receiver 16゛. Transmitter 15. Connection can be made using the wireless receiver 16.

(Problems to be Solved by the Invention) In the conventional device shown in the 2nd TM, (2) the parent device requires as many radio transmitters and radio receivers as the number of child units, so the equipment becomes expensive ( (b) Since at least two sets of wireless channels must be used during an extension call, there are drawbacks such as inability to utilize frequencies effectively.

The present invention has been proposed in order to improve the above-mentioned drawbacks, and its purpose is to: (1) achieve efficient use of frequencies by realizing internal calls between handsets over a single set of wireless channels; ,@An object of the present invention is to provide a cordless telephone device that can reduce the number of wireless transceivers in a parent device to one set.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a cordless telephone comprising a parent device connected to a telephone line and a plurality of handsets connected to the parent device via wireless lines. In the parent device, the parent device includes a set of transmitters, a wireless transmitter with a frequency f, and a wireless receiver with a frequency f, and each slave device has a wireless receiver with a frequency f1 and a wireless receiver with a frequency f! a radio transmitter, means for enabling said radio transmitter to transmit by detecting a transmitting signal level, means for blocking a received signal, and means for stopping said radio transmitter by detecting a receiving signal level; The gist of the invention is a cordless telephone device characterized by comprising: a means for blocking a transmission signal;

(Function) As described above, the present invention provides a cordless telephone device that detects the transmitting level in each handset to enable the wireless transmitter of the handset to transmit, and mutes the receiving signal. , by providing means for stopping the wireless transmitter of the handset by detecting the received signal level,
By providing a set of a wireless transmitter and a wireless receiver in the parent device, it is possible to transmit and receive conversations between the parent device and the child device.

(Example) Next, an example of the present invention will be described. Note that the embodiments are merely illustrative, and it goes without saying that various changes and improvements can be made without departing from the spirit of the present invention.

FIG. 1 shows an embodiment of the cordless telephone device of the present invention. In the figure, 1 is a parent device, and 2a is a main device.

2b indicates a slave unit, and in this figure, the control circuit (
(microcomputer, etc.) and operation units such as dial keys of the handset are omitted.

First, the configuration of the parent device 1 will be explained.

In the figure, 31 is a line relay, 32 is a 2-wire to 4-wire conversion circuit, 33 is a wireless transmitter, 34 is a transmitting antenna, 35
indicates a wireless receiver, and 3G indicates a receiving antenna.

Next, the slave device will be explained. The handset is common to both 2a and 2b, and in the figure, 41a and 41b are receiving antennas,
42a, 42b are radio receivers, 43a, 43b are received signal attenuators, 44a, 44b are received signal level detectors, 45a
, 45b is a receiver, 46a and 46b are transmitting antennas, 4
7a, 47b are radio transmitters, 48a, 48b are transmitting level detectors, 49a, 49b are transmitting signal attenuators, 50a,
50b indicates a transmitter.

Here, the receiving level detectors 44a, 44b detect the signal levels of the handsets 45a, 45b, respectively, and when this is large, the transmitting signal attenuators 49a, 49b are activated,
Prevents the passage of signals 0a and 50b. Further, the transmitting level detectors 48a and 48b are each connected to a transmitter 50a.

The signal level of 50b is detected, and when it is large, the receiving signal attenuators 43a and 43b are activated to suppress the passage of the signal.

The frequency of the radio waves emitted from the parent device 1 is f+, and the frequency of the radio waves emitted from the slave devices 2a and 2b is f2.
It is.

Next, the operation will be explained.

(1) When handsets 2a and 2b communicate with each other, line relay 31 of parent device 1 is open in this case.

(a) When handset 2a performs an extension call operation to handset 2b, control signals are sent and received via parent device 1, and parent device 1 and handsets 2a and 2b share the same communication channel. Move to. That is, the parent device transmits a radio wave with a transmission channel frequency f from the wireless transmitter 33, and the slave devices 2a and 2b receive the radio wave f with their receivers. The radio waves of the transmitting channel frequency f on the handset side are from the handset 2a.

2b waits without transmitting. (In this case, both slave units,
There is no transmission. (b) Next, when the handset 2a transmits a call, a signal is input from the transmitter 50a, passes through the transmit signal attenuator 49a whose attenuation is small, and is input to the wireless transmitter 47a. , are also input to the transmission level detector 48a. Here, when the transmitting signal is detected by the transmitting level detector 48a,
The attenuation amount of the received signal attenuator 43a is detected by the received signal level detector 44.
By switching the radio transmitter 47a so that it does not operate in response to any reception signal and switching the radio transmitter 47a from the stopped state to the operating state, the radio wave rim is transmitted from the transmitting antenna 46a.

Radio waves f! from the receiving antenna 36 of the parent device l! .

When this radio wave is received, the radio receiver 35 detects the radio wave and inputs the transmission signal from the handset 2 a to the 2-wire to 4-wire conversion circuit 32 . Here, since the line relay 31 is open, the transmission signal is totally reflected by the 2-wire-44I conversion circuit 32, is inputted to the radio transmitter 33, and is transmitted by the transmission antenna 34 as a radio wave f.

The radio wave f1 is received by the reception antenna 41b of the handset 2b, detected by the wireless receiver 8142b, and passed through the reception signal attenuator 43b, which has a small amount of attenuation, as a reception signal of the handset 2b, and is transmitted to the handset 45b. is converted into sound by At this time, when a received signal is detected by the received signal level detector 44b, the amount of attenuation of the transmitted signal attenuator 49b is changed to a large value such that the transmitted signal level detector 48b does not operate even with the transmitted signal. As a result, transmission from the handset 2b is interrupted. The radio wave f is also received by the receiving antenna 41a, but the radio wave f is also received by the radio receiving antenna 41a.
Since the signal detected at point a has a large attenuation amount by the received signal attenuator 43a, only a very small sound is generated from the receiver 45a, and the so-called sidetone is suppressed.

Therefore, while the handset 2a is transmitting a call, the wireless transmitter 47a of the handset 2a is in an operating state, and the wireless transmitter 47b of the handset 2b is in a stopped state, so that the radio wave f is transmitted. Only radio waves f. This prevents them from being sent at the same time.

(C) When the handset 2a stops transmitting, the transmitting level detector 48a detects the stop of transmitting, and the receiving signal attenuator 43a
At the same time, the radio transmitter 47a is stopped. Therefore, since the reception signal to the handset 2b stops, the reception level detector 44b detects the stop of reception, and reduces the attenuation amount of the transmission signal attenuator 49b.

(d) When the handset 2b transmits a call, it operates in the same manner as in (6), and the wireless transmitter 47b of the handset 2b becomes operational.
Since the wireless transmitter 47a of the handset 2a is in a stopped state, the radio wave f! Only b is transmitted.

As described above, extension calls between handsets can be made over a 1 m communication channel using only one set of wireless transceivers of the parent device.

([[) When a call is received via the telephone line, the line relay 31 is turned on, and the child 1!2 is transmitted via radio waves f,,fa.
a and 2b can communicate with the outside.

(Effects of the Invention) As described above, the present invention provides a cordless telephone device that detects the transmitting level in each handset, enables the radio transmitter of the handset to transmit, and mutes the receiving signal. and a means for stopping the radio transmitter of the handset by detecting the receiving signal level,
By providing a wireless transmitter and a wireless receiver of 1&[I in the parent device, it is possible to transmit and receive messages between the parent device and the child device. (a) Conventionally, the parent device required two or more sets of expensive transmitters and receivers, but in the present invention, only one set of transmitter and receiver is required for the parent device, reducing costs. I can do it.

(b) Since only one set of wireless channels is used during an extension call, effective use of frequencies is possible.

It has the following effects.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the cordless telephone device of the present invention;
The figure shows a conventional device. 1... Parent device 2a, 2b, slave device 31... Line relay 32... 2-wire to 4-wire conversion circuit 33... Radio transmitter 34... Transmitting antenna 35...Radio receiver 36...Receiving antennas 41a, 41b, receiving antennas 42a, 42b, radio receivers 43a, 43b, received signal attenuators 44a, 44b, received level detector 45a, 45b - Handset 46a, 46b, transmitting antenna 47a, 47b, radio transmitter 48a, 48b, transmitting level detector 49a, 49b, transmitting signal attenuator 50a, 50b - transmitter

Claims (1)

[Claims] In a cordless telephone that includes a parent device connected to a telephone line and a plurality of handsets connected to the parent device via a wireless line, the parent device has a wireless transmitter with a frequency f_1 and a wireless receiver with a frequency f_2. A set of transmitters is provided, and each handset includes a wireless receiver with a frequency f_1, a wireless transmitter with a frequency f_2, and enables the wireless transmitter to transmit by detecting a voice transmission level, A cordless telephone device comprising: means for blocking a received signal; and means for detecting a received signal level to stop the wireless transmitter and block a transmitted signal.