JPH089459A - How to display electric field on-hook of cordless phone - Google Patents

Abstract

PURPOSE:To guess whether a hand set is located at a place to enable speaking even when the slave set is away from a master set by performing an electric field display when the slave set of a cordless telephone is on hook state. CONSTITUTION:At the time of off-hook (during off-hook), radio waves at the frequency of a control channel are periodically radiated from an antenna through a transmission high frequency part 6 and a multicoupler 13 of the master set 1 at fixed intervals. This radio wave is received through the antennal of the slave set 2 and a multicoupler 22 to a reception high frequency part 16, the strength of the radio wave at that time is displayed on a display part 3 on several stages and when the radio wave of the next control channel is received, the display is changed. When the radio wave of the control channel is not received longer than fixed time, that display is turned off. In order to use over two adjacent cordless telephones, the transmission of a periodical control channel is executed after carrier sense at the control channel so that any mutual interference can not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for displaying an electric field when a cordless telephone slave unit is on-hook.

[0002]

2. Description of the Related Art As shown in FIG. 1A, a cordless telephone is composed of a master unit which is connected to a public line network by wire and a slave unit 2 which is wirelessly connected to the master unit 1. The child device 2 can move within a range in which the radio wave emitted by the parent device 1 can be received and within a range in which the parent device 1 can receive the radio wave emitted by the child device 2. In the conventional method, when the base unit 1 and the handset unit 2 are wirelessly connected and the handset unit 2 moves to a place where the base unit 1 cannot be wirelessly connected, the handset unit 4 of the handset unit 2 is connected to the base unit 1. We are informed that we cannot connect wirelessly.

[0003]

In the conventional example described above, the location where the handset 2 cannot wirelessly connect to the base unit 1 while the base unit 1 and the handset 2 are not wirelessly connected (on-hook state). If you move up to, there is a problem that you cannot know it.

[0004]

The present invention solves the problem that it is not possible to know whether a cordless telephone handset is in a place where it cannot wirelessly connect to a parent device when it is on-hook, and even when it is on-hook. It is intended to provide a method of displaying an electric field when a cordless telephone is on-hook, which can determine whether or not a wireless connection can be made.
That is, according to the method of the present invention, the slave unit 2 receives the radio wave of the frequency of the control channel that is periodically emitted from the base unit 1 at a constant interval during off-hook, and the intensity of the radio wave at that time is divided into several times as an electric field. It is characterized by displaying on the display unit 3 and changing the display when the radio wave of the next control channel is received.

[0005]

[Operation] With such a configuration, when the off-hook, the base unit 1 periodically emits a radio wave of the frequency of the control channel, and the radio wave is received by the handset 2 and the radio wave at that time is received. The strength is displayed as an electric field on the display unit 3 several times. This display is changed when the radio wave of the next control channel is received.

[0006]

1 (A) and 1 (B) are a block diagram showing the construction of an embodiment of a cordless telephone according to the present invention and an electric field display example of its cordless handset. 1 in FIG.
Is a master unit that is connected to the public line network 4 by wire, and 2 is a slave unit that is wirelessly connected to the master unit 1. The range in which the radio waves emitted by the master unit 1 can be received and the radio waves emitted by the slave unit 2 are It is possible to move within the range that the base unit 1 can receive. Reference numeral 4 is a public circuit network, 5 and 6 are low and high frequency transmission parts that perform modulation and transmission, 7 is a control part, 8 is a synthesizer part, and 9 and 10 are high and low frequency reception parts that perform reception and demodulation, respectively. Is a PB transmitter, 12 is an IR detector, 13 is a duplexer, 14 is a power supply, and 15 is an AC adapter.

Reference numerals 16 and 17 are high and low frequency parts for receiving and demodulating signals, 18 is a synthesizer part, 19 is a controlling part, 20 and 21 are low and high frequency transmitting parts for modulating and transmitting respectively, and 22 is a duplexer. , 23 is a power supply section, 24 is a charging section,
25 is an AC adapter. In the cordless telephone, there are a control channel for exchanging wireless connection procedures between the master unit 1 and the slave unit 2, and a call channel for actually communicating after completing the connection procedure. In the present embodiment, during off-hook (while off-hook), a radio wave of the frequency of the control channel is periodically emitted from the antenna via the transmission high-frequency unit 6 and the duplexer 13 of the master unit 1 at regular intervals. This radio wave is received by the reception high frequency unit 16 via the antenna of the handset 2 and the duplexer 22, and the strength of the radio wave at that time is displayed as an electric field on the display unit 3 in several steps, and the next control channel Change the display when radio waves are received. When the radio wave of the control channel is not received for a certain period of time, the display is turned off. In order that two or more adjacent cordless telephones can be used, mutual interference does not occur if the above-mentioned periodic control channel transmission is performed after carrier sensing is performed on the control channel.

In the above configuration, when off-hook, radio waves of the frequency of the control channel are periodically emitted from the antenna through the transmission high frequency unit 6 of the base unit 1 and the duplexer 13 at regular intervals, and the radio waves are transmitted to the antenna of the handset 2. The signal is received by the reception high frequency unit 16 via the duplexer 22, and the strength of the radio wave at that time is displayed as an electric field on the display unit 3 in several steps. This display is
It is changed when the radio wave of the next control channel is received. The display is cleared when the radio waves on the control channel have not been received for a certain period of time.

[0009]

As described above, according to the present invention, by displaying an electric field on a cordless telephone handset when it is on-hook, it is possible to determine whether or not the child handset is in a place where a telephone call can be made even if the handset is far from the parent device. You can know the standard.

[Brief description of drawings]

1A and 1B are a block diagram showing a configuration of an embodiment of a cordless telephone of the present invention and an electric field display example of a cordless handset thereof.

[Explanation of symbols]

 1 parent unit 2 slave unit 3 display unit 4 public circuit network 5 transmission low frequency unit 6 transmission high frequency unit 7 control unit 8 synthesizer unit 9 reception high frequency unit 10 reception low frequency unit 11 PB transmission unit 12 IR detection unit 13 duplexer 14 power supply Part 15 AC adapter 16 Reception high frequency part 17 Reception low frequency part 18 Synthesizer part 19 Control part 20 Transmission low frequency part 21 Transmission high frequency part 22 Duplexer 23 Power supply part 24 Charging part 25 AC adapter

Claims (1)

[Claims] 1. A slave unit receives a radio wave of a frequency of a control channel that is periodically emitted from the base unit at a fixed interval when off-hook, and the intensity of the radio wave at that time is displayed as an electric field on the display unit several times. Then, the display method is changed when the radio wave of the next control channel is received.