JPH04156035A - Cordless telephone system - Google Patents

Abstract

PURPOSE:To prevent tapping from being performed by narrowing an arrival range by providing a specific key, controlling radio output at every operation of the key, and decreasing the radio output when significant speech is held. CONSTITUTION:A speech distance switching key 33 is a key to decrease the radio output of a master machine M and a slave machine S in the case where the tapping of the significant speech should be prevented from being performed, and the arrival range of a wave is narrowed by decreasing the radio output, and at that time, the speech is held by approaching the slave machine S to the master machine M. The key 33 switches a signal which switches the radio output of the slave machine S from high to low and vice versa at every operation and switches the transmission output of the master machine M from high to low at every operation of the key 33, and a signal which switches the output from low to high alternately. Thereby, it is possible to make the tapping hard to be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cordless telephone device designed to prevent eavesdropping.

[Prior Art] For example, in the case of a conventional cordless telephone device of a low-power type, radio waves can reach over 100 meters at a line-of-sight distance, so there is a high possibility that it will be overheard by a third party.

For this reason, a confidential communication device that performs data conversion and the like has been proposed.

[Problem to be solved by the invention] However, such a secret communication device is expensive, and adding such an expensive device would make it extremely uneconomical. Although this solves the problem of cigarettes, it has the problem of shortening the communication distance accordingly.

[Means for Solving the Problems] In order to solve such problems, the present invention transmits a control signal to the base unit according to the operation of a specific key and controls the transmission level of the transmission signal to the base unit. This device includes a handset equipped with a control unit and a master unit equipped with a control unit that controls the transmission level of a transmission signal to the handset according to a control signal received from the handset.

[Effect] When a specific key is operated on the handset, the transmission level of the handset changes to
1l and transmits a control signal to the base unit.

The base unit that receives the control signal controls the transmission level to 11. In other words, the wireless output is set high at the beginning of a call, and when a call is to be made that does not want to be intercepted, the transmission output of the base unit and handset is reduced by operating a specific key on the handset.
Place the base unit and slave unit close together to make a call.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, M is a main unit, S is a slave unit, and the main unit M is a line for connecting with an outside line terminal 3. Relay 4. A hybrid circuit 5 that performs 2-wire 4-wire conversion, a transmitter 6, an antenna duplexer 7 that shares the antenna for transmission and reception, an antenna 8, a receiver 9, a synthesizer 10 that controls the frequencies of transmission and reception.
．． A control unit 11 that performs necessary control during transmission and reception, a ROM 12 that stores predetermined data, and an amplifier 13a21.
It is composed of 3b. The child INS includes an antenna 21, an antenna duplexer 22, a receiver 1123, speakers 24 and 30, a microphone 25, a transmitter 26, and a synthesizer 2.
7. Control unit 28. It is composed of a ROM 29, a call key 31, a call end key 32, a call distance switching key 33 which is a specific key, and amplifiers 34a and 34b.

This call distance switching key 33 is used to reduce the wireless output of the base unit and slave unit when it is a concern that an important call is being eavesdropped. It makes it difficult. At this time, the slave unit is brought close to the base unit to talk. Each time this key is operated, the wireless output of the handset changes from high to low and from low to high. Further, for the base unit, as with the slave Il, each time this key is operated, a signal for switching the transmission output from high to low and a signal for switching from low to high are alternately switched.

Note that both the base unit and the slave unit have large transmission outputs at the time of starting the call.

FIGS. 2 and 3 are flowcharts showing the operation of this device, with FIG. 2 showing the operation of the parent device and FIG. 3 showing the operation of the slave device. In FIG. 2, the base unit completes the initial process shown in step 100, and if there is an incoming call in step 101, it performs the incoming call process in step 102, and then judges in step 103 whether or not there is data received by the slave unit.

If step 103 determines that there is data received from the handset, and it is determined that charging is off as shown in step 104, the line is captured in step 105, and the Stellar 7106 transmits line capture data. and performs other processing in step 107, which is step 10.
Even if it is determined in step 4 that charging is not off, the same process is performed if it is determined in step 108 that the call key is pressed.

When you operate the call distance switch key on the handset, if a high transmission output has been selected up to that point, the handset sends a signal to control the transmission output of the base unit to a small value (about this specific point This signal is received by the base unit, and in step 103 it is determined that there is data received by the slave unit, and in step 104 it is determined that it is not a charging off signal, and in step 108, the call key is pressed. It is determined in step 109 that the signal is not a charge-on signal, and in step 110 it is determined that it is not a signal indicating that the cut key has been pressed.

Then, in step 111, it is determined whether or not to increase the wireless output, but this signal is as described above! ! !
Since the purpose is to reduce the line output, step 1
11 is determined to be rNOJ, and in step 112 it is determined to be wireless output rate data.

In this way, when it is determined in step 112 that the data is small wireless output data, and it is determined that the line is being acquired in step 113, in step 114! l! Processing is performed to reduce the line output. This process is performed by the control ill lowering the amplification degree of the amplifier 13a in FIG. It is necessary to get close to the base unit to make a call (as will be explained later, the wireless output of the slave unit is also controlled to be low).

When an important call has ended and the user of the handset wants to make a call at a location far from the base, he operates the call distance switch key to increase the wireless output. As a result, the slave unit outputs control data for increasing the wireless output of the base unit, so in step 103 it is determined whether there is data received by the slave unit, and in the same way as described above, in step 104, the determination of charging off is made.
Determination that the call key is not pressed in step 108, determination that charging is not on in step 109, step 11
It is determined that the 0 cut key has not been pressed. Therefore, in step 111, a determination is made as to whether the wireless output is large.
When it is determined in step 121 that the line is being acquired, a process of setting the wireless output to high is performed as shown in step 122.

If it is determined in step 109 that charging is on, or that the cut key is pressed in step 110, and that the line is being captured in step 125, the process proceeds from step 126 to step 128. As shown, line release processing, line release data transmission processing, and wireless output large set processing are performed. That is, when ending a call, a process is performed in which the wireless output is increased.

Note that if it is determined in step 125 that the line is not being acquired, other data processing is performed as shown in step 129.

FIG. 3 is a flowchart showing the operation of the slave device, in which after initial processing in step 200, step 20
When it is determined in Step 1 that charging is not turned off, in Step 202 that charging is not turned on, and in Step 203 that it is determined that a key has been pressed,
In step 204, it is determined whether the call distance switching key has been pressed. If it is determined in step 205 that the line is being acquired, then in step 206 it is determined whether the wireless output is large.

If it is determined that the wireless output at this point is large,
In step 207, a process of transmitting wireless power rate data for lowering the wireless output of the base unit is performed. Through this process, a signal for lowering the wireless output is sent from the slave unit to the MIR. Then, in step 208, a process is performed to set the wireless output of the slave unit to a small value in order to lower the wireless output of the slave device.

In step 206,! ! If it is determined that the line output is low, in step 209, a process of transmitting large wireless output data is performed to increase the wireless output of the base unit. Through this process, the wireless output from the slave unit to the base unit is increased. A signal is sent out. Then, in step 210, processing is performed to set the wireless output of the slave device to high.

If it is determined in step 204 that the call distance switching key has not been operated, the corresponding key data transmission process is performed as shown in step 211, and step 201
When it is determined that charging is off, processing for transmitting charging off data is performed as shown in step 212, and step 2
If it is determined in step 02 that charging is on, charging on data transmission processing as shown in step 213 is performed.

Thereafter, the handset performs other processing in step 221 as necessary, that is, processing necessary for the telephone.

The above is the operation when a connection is being made, but before this operation is performed, it is necessary to perform a connection operation. The processing is from step 225 onwards.

That is, if it is determined in step 225 that the data transmitted from the base unit is line capture data, the line capture lamp set process is performed in step 226, the call lamp lighting process is performed in step 227, and then step 221 is performed. Perform other processing.

If it is determined in step 225 that the received data is not line acquisition data, and if it is determined in step 228 that it is not line release data, other received data processing in step 228 is performed. If it is determined in step 228 that the data is line release data, processing of the line capture flag set in step 235;
Processing of turning off the call lamp in step 226, step 23
Processing for the wireless output large set No. 7 is performed. That is, the wireless output of the handset is also set to be high when the call ends. This process is performed by controlling the amplification degree of the amplifier 34a of the slave device.

Although the above embodiment is explained for line calls, it can be done similarly for extension calls, and although the wireless output is switched in two stages, it can be switched to multiple stages, or the CPU can be set to the optimal level by electrolyte detection. A method of controlling this may also be considered.

[Effects of the Invention] As explained above, the present invention provides a specific key and controls the wireless output each time the key is operated.
When making an important call, lowering the wireless output reduces the communication range and makes it difficult for eavesdropping to occur. 4,

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the parent device, and FIG. 3 is a flowchart showing the operation of the slave device. 6.26--Transmitter, 7,22--Antenna duplexer, 9,23--Receiver, 10゜27--Synthesizer, 11.28--Control unit, 13a, 34
a-...-Amplifier.

Claims (1)

[Claims] A handset equipped with a specific key, a control unit that transmits a control signal to the base unit in response to the operation of the specific key, and controls the transmission level of the transmission signal to the base unit, and a control signal received from the slave unit. A cordless telephone device comprising a base unit and a base unit provided with a control unit that controls the transmission level of a transmission signal to the slave unit according to the transmission level.