JPH07114429B2 - Cordless telephone device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is used for a cordless telephone. 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]

In a cordless telephone, a fixed device is connected to the in-home wiring, and a call can be made using a portable wireless device wirelessly connected to the fixed device. With conventional cordless phones, if the user turns off the power of the transceiver during a call, or if the battery capacity of the transceiver drops and it becomes difficult to continue the call, the fixed device will be in a call state. While holding, the radio side becomes inactive. In such a case, it is general that the fixed device detects the carrier disconnection and ends the call.

[Problems to be solved by the invention]

However, in conventional cordless telephones, when the radio ends the call due to power cut or power supply voltage drop, the fixed device monitors the time when the carrier is continuously lost and the call status remains until the time elapses. Holding That is, since the fixing device during this period maintains the state of transmitting radio waves, there is a drawback that the radio waves are wasted.

Further, in such a case, since the wireless device ends the call before the fixed device, the fixed device still maintains the call even when the wireless device is operated again to start the calling process. Therefore, there is a drawback that the call may fail.

Further, when the fixed device is performing carrier disconnection detection, if the same frequency above a certain level exists in the channel due to interference or the like, the fixed device cannot detect the channel disconnection and the call end processing cannot be executed. It was

SUMMARY OF THE INVENTION The present invention solves the above problems and provides a cordless telephone device that can terminate a call even on the fixed device side when the call is terminated due to a power cut or power supply voltage drop of the wireless device. To aim.

[Means for solving problems]

The cordless telephone device of the present invention includes means for detecting, in the radio, a power supply voltage drop during a call or a drop in the power supply voltage to the extent that it is difficult to continue the call, and the fixed device is terminated by the output of the detecting means. And a means for giving notification.

[Action]

If the power supply voltage drops to the extent that it is difficult to maintain a call due to the power switch being cut off or the battery being consumed during a call, the wireless device sends it to a fixed device during normal call termination processing before stopping the transmission of radio waves. A signal equivalent to the signal to be transmitted is transmitted. The fixed device ends the call by the same process as in the case of ending the 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 line 10 and a wireless device 3 connected to the fixed device 2 via a wireless transmission line 11.

FIG. 2 shows a block diagram of the fixing device 2.

The fixed device 2 includes a central processing unit 24 and a program memory 26 as means for performing a call ending process for the fixed network 1 in response to a call ending notification from the wireless device 3.

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

The push button dial signal transmitter / receiver 25 is the wireless transmitter / receiver 23.
Receives a dial signal from the central processing unit 24,
This is converted into a push button dial signal (DTMF signal) and sent to the fixed network 1.

FIG. 3 shows a block diagram of the wireless device 3.

The wireless device 3 has a means for detecting a power supply interruption during a call or a drop in the power supply voltage to the extent that it is difficult to continue the call, and a power switch 34 connected to the central processing unit 35 to detect power on or off. Low voltage detection circuit
Equipped with 38. The central processing unit 35 serves as means for notifying the fixed device 2 of the end of the call by the output of the detecting means.
And a program memory for storing its operation program
With 39.

The wireless transmission / reception unit 31 is connected to the handset 32, the transmitter 33, and the central processing unit 35. A power switch 34, a gate circuit 36, a low voltage detection circuit 38, a program memory 39, a display unit 40 and an operation key 41 are further connected to the central processing unit 35. The low voltage detection circuit 38 is connected to the battery 37. Gate circuit 36
Are connected between the battery 37 and each part of the wireless device 3.

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

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

Normally, when the user presses the end call button of the operation key 41, the central processing unit 35 sends an end call signal to the wireless transmission / reception unit 31. The wireless transmission / reception unit 31 sends this end signal to the fixed device 2 via the wireless transmission path 11. Central processing unit
Reference numeral 35 sends a transmission / reception control signal to the wireless transmission / reception section 31 to stop its operation, and closes the gate circuit 36 to stop the power supply to each section.

When the power switch 34 is turned off during a call by the operator's operation, the central processing unit 35 detects this and does not immediately stop the transmission of radio waves, but terminates the call from the wireless transmission / reception unit 31 to the fixed device 2. After transmitting the signal, the gate circuit 36 is closed to stop the supply of the power supply voltage. The fixed device 2 is a radio 3
The central processing unit 24 detects the call end signal from and ends the call.

When the voltage of the battery 37 drops, the low-voltage detection circuit 38 finds that it is difficult to maintain a call and that the fixed processing device 2 still has enough voltage to transmit a call termination signal. A low voltage detection signal is sent to the unit 35. The central processing unit 35 causes the display unit 40 to display a low voltage alarm and causes the wireless transmission / reception unit 31 to transmit an end signal to the fixed device 2, and then closes the gate circuit 36 to stop the supply of the power supply voltage. The fixed device 2 detects the call termination signal from the wireless device 3 by the central processing unit 24 and terminates the call.

In the above embodiment, the configuration is such that the entire operation of the wireless device 3 is stopped when the voltage drops, but the present invention can be similarly implemented by stopping only the wireless transmission / reception unit 31. Further, the present invention can be similarly implemented in a multi-zone cordless telephone device which is provided with a plurality of fixed devices and can talk over a wide range.

〔The invention's effect〕

As described above, the cordless telephone device of the present invention is
When the power of the wireless device is turned off during a call and when the voltage of the battery drops, both the wireless device and the fixed device can be immediately put into the call end state. Therefore, there is an effect that the fixed device does not continue to operate and radio waves can be effectively used. Further, it is possible to prevent only the fixed device from maintaining the call state, and the call failure does not occur. Further, even if the same frequency above a certain level exists due to interference or the like in the channel used by the wireless device during a call, the fixed device can perform a call process.

[Brief description of drawings]

FIG. 1 is a block configuration 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 a wireless device. FIG. 4 is a diagram showing a control flow of a call end process of the central processing unit of the wireless device. 1 ... Fixed network, 2 ... Fixed device, 3 ... Radio, 10 ...
Wired transmission line, 11 …… Wireless transmission line, 21 …… Line relay,
22 …… 2-wire to 4-wire conversion circuit, 23, 31 …… Wireless transceiver, 2
4, 35 ...... Central processing unit, 25 ...... Push button dial signal transmitting / receiving unit, 26, 39 ...... Program memory, 27 ...... Carrier detection circuit, 32 ...... Handset, 33 ...... Transmitter, 34 ...... Power supply Switch, 36 gate circuit, 37 battery, 38 low voltage detection circuit, 40 display, 41 key operation.

Claims (1)

[Claims] 1. A fixed device connected to a fixed network via a wired transmission line, and a wireless device connected to the fixed device via a wireless transmission line, wherein the fixed device is a telephone call from the wireless device. In a cordless telephone device including means for performing call termination processing for the fixed network by a termination notification, the wireless device includes means for detecting a power supply interruption during a call or a drop in power supply voltage to the extent that it is difficult to continue the call, A cordless telephone device including means for notifying the fixed device of the end of the call by the output of the detecting means.