JPH0239756A - Cordless telephone system - Google Patents

Abstract

PURPOSE:To prevent a fixed device from continuously operating and to effectively utilize a radio wave by immediately completing speaking on the both sides of a radio and the fixed device when the power of the radio is turned off during speaking or the voltage of a battery is decreased. CONSTITUTION:When a power source switch 34 is turned off during the speaking by an operator, a central processing part 35 detects it, transmits a clearing signal from a ratio transmitter-receiver part 31 to the fixed device, then, closes a gate circuit 36, and stops the supply of a supply voltage. The fixed device detects the clearing signal from the radio by a central processing part 24, and complets the speaking. When the voltage of a battery 37 is decreased, a low voltage detecting circuit 38 is difficult to maintain the speaking, in spite of it, and when the remaining of the voltage, which can transmit the clearing signal to the fixed device, is detected, the low voltage detecting signal is sent to CPU 35. The CPU 35 displays a low voltage alarm on a display part 40, transmits the clearing signal from the radio transmitter-receiver part 31 to the fixed device, thereafter, closes the gate circuit 36, and stops the supply of the supply voltage. The fixed device detects the clearing signal, and completes the speaking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is applied to cordless telephones. In particular, the present invention relates to control when the power of the wireless device is cut off or the power supply voltage drops during a call.

[Conventional technology]

With a cordless telephone, a fixed device is connected to the in-house wiring, and a telephone call can be made using a portable radio device that is wirelessly connected to the fixed device.

With conventional cordless telephones, if the user turns off the power switch of the radio during a call, or if the radio's battery capacity decreases and it becomes difficult to continue the call, the fixed device will automatically switch off the call. While holding the button, the radio device stops operating. In such cases, it is common for the fixed device to detect the carrier disconnection and terminate the call.

[Problem that the invention seeks to solve]

However, with traditional cordless telephones, if the radio ends a call due to a power outage or brownout, the fixed equipment monitors the length of time the carrier has been uninterrupted and continues to communicate until that time has elapsed. The state is maintained. That is, since the fixing device continues to transmit radio waves during this time, there is a drawback that the radio waves are wasted.

In addition, in such a case, the radio will end the call before the fixed device, so even if the radio is activated again and the call process is started, the fixed device will still be maintaining the call. Therefore, there is a drawback that the call may fail.

Furthermore, when a fixed device is detecting a carrier disconnection, if the same frequency exists at a certain level or higher on that channel due to interference or other reasons, the fixed device cannot detect the channel disconnection and cannot perform call termination processing. Ta.

The present invention solves the above problems and provides a cordless telephone device that can also terminate a call on the fixed device side when the wireless device ends the call due to a power cut or a drop in power supply voltage. purpose.

[Means for solving problems]

The cordless telephone device of the present invention includes means for detecting a power cut during a call or a drop in power supply voltage to such an extent that it is difficult to continue the call in the wireless device, and an output from the detecting means to instruct the fixed device to terminate the call. The method is characterized by comprising a means for notifying the user.

[For production]

During a call, if the power supply voltage drops to such an extent that it becomes difficult to maintain a call due to the power switch being turned off or the battery running out, the radio transmits signals to the fixed device during normal call termination processing before stopping transmitting radio waves. Sends a signal equivalent to the signal to be sent. The fixed device terminates the call using the same process as when terminating a normal call.

〔Example〕

FIG. 1 shows a block diagram of a cordless telephone device according to an embodiment of the present invention.

This cordless telephone device includes a fixed device 2 connected to a fixed network 1 via a wired transmission path 10, and a radio device 3 connected to the fixed device 2 via a wireless transmission path 11.

FIG. 2 shows a block diagram of the fixing device 2. As shown in FIG.

The fixed device 2 includes a central processing unit 24 and a program memory 26 as means for performing a call termination process to the fixed network 1 based on a call termination notification from the radio device 3.

To explain in more detail, the audio circuit between the fixed device 2 and the fixed network 1 is connected to a wireless transmitter/receiver 23 via a line relay 21 for line opening/closing and a two-wire/four-wire conversion circuit 22. In addition to the program memory 26, the central processing unit 24 is connected to a push button dial signal transmission/reception unit 25 and a carrier detection circuit 27, and is connected to the wireless transmission/reception unit 23 via a data signal line and a transmission/reception control line. .

The push button dial signal transmitting/receiving section 25 receives and receives the dial signal from the wireless transmitting/receiving section 23 via the central processing section 24, and converts it into a push button dial signal (DTMF signal).
and sends it to the fixed network 1.

FIG. 3 shows a block diagram of the radio device 3. As shown in FIG.

This radio device 3 has a means for detecting a power cut during a call or a drop in power supply voltage to such an extent that it is difficult to continue the call, and a power switch 34 is connected to the central processing unit 3S and can detect whether the power is turned on or off. In addition to the configuration, the low voltage detection circuit 38 is also provided. Further, as means for notifying the fixed device 2 of the end of the call based on the output of the detecting means, a central processing section 35 and a program memory 39 for storing its operating program are provided.

The wireless transmitting/receiving section 31 is connected to a receiver 32, a transmitter 33, and a central processing section 35. Further connected to the central processing unit 35 are a power switch 34 , a gate circuit 36 , a low voltage detection circuit 38 , a program memory 39 , a display unit 40 and operation keys 41 . Low voltage detection circuit 38 is connected to battery 37 . The gate circuit 36 is connected between the battery 37 and each part of the radio device 3.

When the user turns on the power switch 34, the central processing unit 35 opens the gate circuit 36 and supplies power from the battery 37 to each part of the radio device 3.

FIG. 4 shows the control flow of the central processing unit 35 at the end of a call.

Normally, when the user presses a call end button on the operation key 41, the central processing section 35 sends a call end signal to the wireless transmitting/receiving section 31. The wireless transmitter/receiver 31 sends this call termination signal to the fixed device 2 via the wireless transmission path 11. Further, the central processing unit 35 sends a transmission/reception control signal to the wireless transmission/reception unit 31 to stop its operation, and also causes the gate circuit 3
6 to stop power supply to each part.

When the power switch 34 is turned off during a call by the operator's operation, the central processing unit 35 detects this, and instead of immediately stopping the transmission of radio waves, the wireless transmitting/receiving unit 31 sends a message to the fixed device 2 to end the call. After transmitting the signal, gate circuit 3
6 to stop the supply of power supply voltage. The fixing device 2 is
The central processing unit 24 detects a call termination signal from the wireless @3 and terminates the call.

When the voltage of the battery 37 decreases, the low voltage detection circuit 38
Difficulty maintaining a call and still fixed device 2
When it is detected that there is enough voltage remaining to send a call termination signal, a low voltage detection signal is sent to the central processing unit 35. The central processing unit 35 causes the display unit 40 to display a low voltage warning, causes the wireless transmitter/receiver unit 31 to transmit a call termination signal to the fixed device 2, and then closes the gate circuit 36 to stop supplying the power supply voltage. In the fixed device 2, the central processing unit 24 detects the end-of-call signal from the wireless device 3, and ends the call.

In the above embodiment, the entire operation of the radio device 3 is stopped when the voltage drops, but the present invention can be implemented in the same way even if only the radio transmitting/receiving section 31 is stopped. Further, the present invention can be similarly implemented with a multi-zone cordless telephone device that is equipped with a plurality of fixed devices and can make calls over a wide range.

〔Effect of the invention〕

As explained above, the cordless telephone device of the present invention includes:
When the power of the wireless device is turned off during a call or when the battery voltage drops, both the wireless device and the fixed device can be brought into a call termination state immediately. Therefore, the fixed device does not continue to operate, and radio waves can be used effectively. In addition, it is possible to prevent only the fixed device from maintaining the call receipt and message, thereby preventing call failure from occurring.

Furthermore, even if the channel that the radio was using during the call has the same frequency above a certain level due to interference or otherwise, the fixed device can process the call.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a cordless telephone device according to an embodiment of the present invention. FIG. 2 is a block diagram of the fixing device. FIG. 3 is a block diagram of the radio device. FIG. 4 is a diagram showing the flow of control of call termination processing by the central processing unit of the wireless device. 1...Fixed network, 2...Fixed device, 3...Wireless device,
10...Wired transmission line, 11...Wireless transmission line, 21.
...Line relay 22...Two-wire four-wire conversion circuit, 23.
31... Wireless transmitting/receiving section, 24. 35... Central processing section, 25... Push button dial signal transmitting/receiving section, 26.
39... Program memory, 27... Carrier detection circuit, 32... Receiver, 33... Transmitter, 34...
・Power switch, 36... Gate circuit, 37... Battery, 38... Low voltage detection circuit, 40... Display section, 4
1... Operation key. Patent Applicant Nippon Telegraph and Telephone Corporation Representative Patent Attorney Nao Ide Takashi Kabuto Layer, Block Beni 3 Figures

Claims (1)

[Claims] 1. A fixed device connected to a fixed network via a wired transmission path, and a radio device connected to the fixed device via a wireless transmission path, wherein the fixed device is connected to the wireless device. In a cordless telephone device that includes means for performing call termination processing to the fixed network based on a call termination notification from the wireless device, the wireless device detects a power outage during a call or a drop in power supply voltage to such an extent that it is difficult to continue the call. A cordless telephone device comprising: means for notifying the fixed device of the end of a call based on the output of the detecting means.