JPH04820A - Cordless automobile telephone system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) TECHNICAL FIELD The present invention relates to a cordless telephone device for automobiles.

(Prior Art) In general, this type of cordless telephone device includes a car phone radio device as a mobile station that manually receives radio signals from a car phone base station (hereinafter simply referred to as a base station), which is a fixed station, and It consists of a base unit that is connected to a car phone radio, and a slave unit that communicates audio signals and control signals wirelessly with the base unit.

FIG. 5 shows the configuration of a conventional cordless telephone device used for home use.
09 and a slave unit 111 that wirelessly communicates audio signals and control signals with the base unit 109.

In this case, if the distance between the base unit 109 and the handset 111 increases and exceeds the limit of the electric field strength of the radio waves, a cordless telephone cannot be used. The device is configured to display that a call cannot be made.

(Problem to be Solved by the Invention) However, in the conventional cordless telephone device described above, when the distance between the base unit 109 and the handset 111 exceeds the limit of the field strength of radio waves, a message indicating that cordless calls cannot be made is displayed. However, if the distance between the base unit 109 and the handset 111 exceeds the limit of the field strength of the radio waves, such as when the base unit is connected to a car phone radio, Even if you do not have a car phone radio or base station, if you move outside the service area, or if you are located underground or in a tunnel even if you are located within the service area, a display will notify you that cordless calls are not possible. This poses a problem in that it is inconvenient for users.

SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, it is an object of the present invention to provide a cordless telephone device for automobiles that can reliably notify that cordless telephone calls cannot be made.

[Structure of the Invention (Means for Solving the Problems) In order to achieve the above object, the present invention provides that, as shown in FIG. 1, only wireless communication is possible between a car phone radio and a base station. a first detecting means 1 for detecting; a second detecting means 3 for detecting that only wireless communication is possible between a base unit and a slave unit connected to the mobile phone radio;
, notifying means 5 for notifying when it is detected that at least one of the second detecting means is unable to perform wireless communication;
It is equipped with the following.

(Function) With the above-described configuration, the present invention not only notifies the second detection means 3 that wireless communication is not possible between the base unit and the slave unit, but also uses the first detection means 1 to notify the mobile phone radio Since the notification means 5 notifies that wireless communication is not possible between the base station and the base station, it is possible to reliably notify that cordless communication is not possible.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings. FIGS. 2 and 4 are explanatory diagrams showing an embodiment of the automotive cordless telephone device according to the present invention.

First, the overall configuration of this embodiment will be explained with reference to FIG.

A car phone radio (MSS) 7 transmits and receives car phone radio waves to and from a base station (not shown) via an antenna, and also sends and receives voice signals and the like to and from the base unit 9 via a telephone line. I do.

The base unit 9 transmits and receives audio signals to and from the car phone radio 7 to and from the handset 11 via radio.

The slave unit 11 is driven by a built-in power supply and transmits and receives audio signals to and from the base unit 9 in a so-called cordless manner. Charging will occur automatically.

FIG. 3 shows a base unit 9 of the automotive cordless telephone device, and this base unit 9 receives a wireless signal from the handset 11 shown in FIG. a receiving circuit 31 that converts the audio signal into a voice signal), an amplifier circuit 32 that amplifies the audio signal from the receiving circuit 31, a telephone line,
It has a hybrid transformer circuit 33 that performs 2-wire to 4-wire conversion of audio signals transmitted and received via L2. Note that the telephone line L2 is connected to a car telephone radio 7.

The base unit 9 also has a transmitting circuit 3 that modulates control signals such as received voice signals and ID codes, and transmits them wirelessly to the slave unit 1.
4, a telephone line, a health signal detection circuit 35 that detects a bell signal arriving at L2, and a control circuit 36 that controls the entire cordless telephone device. If the distance between the two exceeds the field strength limit of the radio waves, an out-of-range signal is output.

The base unit 9 further converts the serial data from the car phone radio 7 into parallel data, and converts the serial data from the car phone radio 7 into parallel data.
a decoder 37 that detects an out-of-range signal when the base station cannot communicate with the base station, such as when the base station moves outside the service area of the base station or is located underground or in a tunnel even if it is located within the service area; This out-of-service signal and control circuit 36
A gate circuit 39 that outputs a logical sum signal of out-of-service signals from
and a driver 39 that drives the display 40 using the output signal of the gate circuit 38.

As shown in FIG. 4, the handset 11 includes a receiving circuit 41 that demodulates the wireless signal from the base unit 9 and converts it into a low frequency signal, and amplifies the receiving audio signal from the receiving circuit 41 and sends it to a speaker. 43, a transmitting circuit 45 for wirelessly transmitting voice signals and control signals from the microphone 44 to the base unit 9, a receiving circuit 41, and an amplifying circuit 42.
, a power supply circuit 49 for supplying power to the transmission circuit 45, etc.
etc.

The handset 11 also includes a control circuit 50 that controls the entire handset 11.
, a dial circuit 51 for transmitting dial information to the base unit 9 via a transmitter circuit 45, a timer 52 for measuring various control times, and a keyboard 53 consisting of dial keys, function keys, a power switch, etc. have

The control circuit 36 of the base unit 9 and the control circuit 50 of the slave unit 11 transmit and receive preset ID codes, and if the ID codes do not match, the operation of the amplifier circuits 32 and 42 is prohibited.

Next, the operation of the above embodiment, particularly the operation of the base unit 9, will be explained.

The control circuit 36 of the base unit 9 measures the electric field strength of the wireless signal from the slave unit 11, and when the field strength becomes less than a predetermined value, the distance between the base unit 9 and the slave unit 11 becomes smaller than the field strength of the radio wave. Outputs an out-of-range signal indicating that the limit has been exceeded.

Furthermore, if the car phone radio 7 moves outside the service area of the base station, or is located underground or in a tunnel even if it is located within the service area, it will indicate that it cannot communicate with the base station. Outputs out-of-service signal.

When at least one of the out-of-service signals is input to the gate circuit 38, the output signal of the gate circuit 38 becomes high level, and the driver 39 causes the display 40 to light up.

Therefore, according to the above embodiment, when the distance between the base unit 9 and the handset 11 exceeds the limit of the electric field strength of the radio waves, it is possible to notify that cordless calls cannot be made, and also to notify the mobile phone wireless When connected to the base station 7, even if the distance between the base unit 9 and the handset 11 does not exceed the limit of the radio field strength, the car phone radio 7 may move outside the base station service area or the service may be interrupted. Even if you are located within the area but are underground or in a tunnel and cannot communicate with the base station, you can be notified that only cordless calls are possible.

As described above, according to this embodiment, a single display device,
For example, by looking at the display 40 provided on the base device 9, it is possible to reliably recognize the state in which communication is not possible.

In the above embodiment, the display device 40 is turned on to notify that cordless phone calls are not possible, but the notification may be made by means of sound or the like.

Further, in the above embodiment, the base unit is provided with a means for notifying that cordless telephone calls cannot be made, but it goes without saying that the means may be provided in the slave unit.

[Effects of the Invention] As explained above, the cordless telephone device for automobiles of the present invention detects whether wireless communication is not possible between the automobile telephone radio and the base station or between the base unit and the handset. Since the system is configured to notify the user when a cordless call is unavailable, it is possible to reliably notify the user that cordless calls are not possible.

[Brief explanation of drawings]

Fig. 1 is a complaint response diagram, Fig. 2 is a block diagram showing the overall configuration of a cordless telephone device for a car according to an embodiment of the present invention, and Fig. 3 shows the detailed configuration of the base unit shown in Fig. 2. FIG. 4 is a block diagram showing a base unit of a cordless telephone device for an automobile according to an embodiment of the present invention, and FIG. 5 is a block diagram showing a conventional cordless telephone device. 36... Control circuit (first detection means), 37... Decoder (second detection means), 40... Display device (notification means). Agent Patent Attorney Hidekazu MiyoshiFigure 4Figure 5

Claims (1)

[Scope of Claims] A first detection means for detecting that wireless communication is not possible between a car phone radio and a base station, and a base unit and a slave unit connected to the car phone radio. a second detection means for detecting that wireless communication is not possible between the two; and a notification means for notifying when at least one of the first and second detection means detects that wireless communication is not possible. Cordless telephone equipment.