JPH05244231A - Cordless telephone set - Google Patents

Abstract

PURPOSE:To provide a cordless telephone set in which talking is available even in the case of a commercial power failure or over-discharge of a battery power supply or the like. CONSTITUTION:A modular plug 18 plugged into a modular jack 19 to which a modular plug of a master set is provided to a slave set in the cordless telephone set comprising the master set and the slave set. Thus, the slave set on power failure of the cordless telephone set is acted by a line current from a telephone line 20 by having only to plug to the modular plug 18 to the modular jack 19 of the telephone line 20 so as to interrupt a speech radio line with the master set by changeover.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless telephone, and more particularly to a cordless telephone.

[0002]

2. Description of the Related Art As is well known, a cordless telephone comprises a master unit and a slave unit connected to a telephone line, and a call signal is transmitted and received between the master unit and the slave unit by a radio wave of low power or low power output. In order to enable the transmission and reception of the call signal, in addition to the line current from the telephone exchange station, the main unit has commercial power as a power source for emitting radio waves, and the slave unit has the main unit. A battery power source is required as a power source necessary to emit radio waves for the same purpose.

Therefore, even if the power source of the slave unit is in the so-called battery exhausted state even when there is a power failure or when there is no power failure, the subscriber of the cordless telephone can always use the line current from the telephone exchange office in order to always make a call. It was necessary to install a non-cordless phone with the conventional configuration that enables calls with.

[0004]

Therefore, in the conventional cordless telephone, when the commercial power source is cut off, the built-in battery of the slave unit is over-discharged, or the battery is uncharged, the conventional cordless telephone is not provided at all. It is impossible to make a call, and in order to make it possible, it has been uneconomically necessary to have a telephone having a conventional structure that can make a call only with the line current, as described above.

It is an object of the present invention to provide a cordless telephone which can solve the above-mentioned call failure at the time of a power failure of the cordless telephone with a simple structure without installing an uneconomical conventional telephone.

[0006]

The present invention comprises a master unit connected to a telephone line through a modular jack, a transmission amplifier and a reception amplifier, and sends and receives voice signals to and from the master unit by radio waves. In a cordless telephone having a cordless handset capable of making a call by
A modular plug to be replaced by the modular jack, a bell detector, a telephone line interface circuit including a telephone line current detecting means, and a detection output of the line current detected by the interface circuit, thereby the transmission amplifier And a receiving amplifier, and a switching switch for switching and connecting the bell detector to the interface circuit and the ringer, respectively.

[0007]

According to the present invention, the cordless handset detects the line current by a simple operation of replacing the modular plug, and the cordless handset switches the constitution of the cordless handset to the same function as a conventional telephone. When a power failure occurs in a cordless telephone that is currently in use, or when the battery of a cordless handset is exhausted, a call can be made.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the configuration of an embodiment of the present invention.
The cordless telephone handset is shown as a block diagram. In FIG. 1, reference numeral 1 is an antenna, 2 is a transmitting unit in a cordless telephone configuration, 3 is a receiving unit, and these constitute a high frequency unit (RF unit) 4. Reference numerals 5 and 6 are changeover switches, and 7 is a transmission amplifier, which amplifies the voice from the microphone 8 to a required level. Reference numeral 9 is a receiver amplifier, and the receiver output is output as voice by the receiver 10. 11 is a changeover switch, 12 is a ringer (speaker) that acoustically outputs an incoming signal, 13 is a microcomputer, 14
Is a keypad that outputs a dial signal, and 15 is a battery power supply. Further, 16 is an interface circuit with a telephone line including a means for detecting a line current, 17 is a bell detector for detecting an incoming signal, 18 is a modular plug, and 19 is a modular jack connected to a telephone line 20. This is outside the scope of the present invention. The interface circuit 16, the bell detector 17, the modular plug 18, and the other changeover switches 5, 6, 11 and the like having the above configuration are additionally configured in the conventional slave unit.

The present invention is configured as described above and operates as follows.

First, when the power supply is cut off due to a power failure or the like and the master unit (not shown) cannot make a call, the modular plug of the master unit attached to the modular jack 19 connected to the telephone line 20 is pulled out, and the present invention is used instead. Replace it with the modular plug 18 provided on the child machine.

By the replacement, the line current supplied from the exchange (not shown) via the telephone line 20 is applied to the interface circuit 16 to supply power to the microcomputer 13. As a result, the microcomputer 13 causes the changeover signals of the changeover switches 5 and 6 and the ringer 12 to operate.
A switching signal of (switch) is output to disconnect the transmitter 2 and the receiver 3, and at the same time, the output sides of the transmitter amplifier 7 and the receiver amplifier 9 are connected to the interface circuit 16, and the ringer 12 is connected to the bell. Connected to the output side of the detector 17.

As described above, in the cordless telephone of the present invention, when the power failure occurs, the cordless telephone can cut the wireless communication circuit with the base unit by simply replacing the modular plug 18.
A transmission / reception circuit that uses the line current of the telephone line as a power source is configured, and the bell detector 17 can ring the ringer 12 to notify of an incoming call. In addition, even if it is not a power outage, if the call is not possible with the battery power of the slave unit's battery power 15 being up, replacing the modular plug 18 with the modular jack 19 connected to the telephone line 20 in the same way as above will cause a power outage. You will be able to talk as well as when.

[0013]

As described above, the cordless telephone of the present invention constitutes a transmission / reception circuit which uses the line current as a power source only by mounting the modular plug on the telephone line when a power failure occurs or when the battery of the slave unit goes dead. Therefore, it is useful as an emergency phone because it can detect incoming calls as a matter of course, and it works only with the line current that the subscriber of the cordless phone has prepared for emergency in order to ensure the call. The need to install a telephone is eliminated and the utility value of a cordless telephone will be further enhanced.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

[Explanation of symbols]

1 ... Antenna, 2 ... Transmitter, 3 ... Receiver, 4 ... R
F section, 5, 6, 11 ... Changeover switch, 7 ... Transmission amplifier, 8 ... Microphone, 9 ... Reception amplifier, 10 ... Receiver, 12 ... Ringer, 13 ... Microcomputer,
14 ... Keypad, 15 ... Battery power, 16 ... Interface circuit, 17 ... Bell detector, 18 ... Modular plug, 19 ... Modular jack, 20 ... Telephone line.

Claims (1)

[Claims] 1. A call can be made by exchanging a voice signal between a master unit connected to a telephone line via a modular jack and a master unit equipped with a transmission amplifier and a reception amplifier by radio waves. In a cordless telephone having a cordless handset, a modular plug which is connected to the cordless handset by replacing the modular jack, a bell detector, an interface circuit with a telephone line including a means for detecting a telephone line current, and the interface circuit. A cordless telephone, comprising: a transmitter switch, a receiver amplifier, and a changeover switch that connects the bell detector to the interface circuit and the ringer, respectively, according to the detection output of the line current detected by the cordless telephone.