JPH10247968A - Radio telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To mentally urge transmission in a small voice and to improve the effect of a privacy mode by increasing the gain of a transmission volume adjustment means and increasing the gain of a reception volume adjustment means at the time of the privacy mode. SOLUTION: When privacy mode selection signals S are supplied to a man machine control circuit 14 by the operation of a privacy button 12, the switch 3 of a high cut filter is turned ON by signals A, the signals B are supplied to a transmission volume adjustment amplifier 5 and the gain is increased 6dB. A volume level at the point of time is read from a volume level memory 13 and switch signals C to increase the gain of a negative feedback operational amplifier 81 to 6dB or 12dB or to maintain it corresponding to data are supplied to the switch 9. Thus, the noise of a high band component included in transmission voice signals D is eliminated, and even when a transmitter speaks in a small voice, a receiver clearly hears it in a sufficient volume, a reception voice level is increased simultaneously, the transmitters naturally lowers the voice as a mental effect and the privacy mode effect is demonstrated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio telephone used for a PHS (Personal Handy Phone System), an automobile portable telephone system and the like.

[0002]

2. Description of the Related Art A radio telephone of this type includes a microphone and a speaker, and transmits a transmission voice input to the microphone as a radio voice signal from a transmission / reception circuit to a partner station, and wirelessly transmits the voice from the partner station. An incoming audio signal is received by a transmission / reception circuit and output from a speaker as received audio.

[0003] By the way, since wireless telephones are often used outdoors, for example, when used in a platform at a station or the like, even if the user does not want to be known to others around him in a whisper, it is sufficient for the transmitting party. 2. Description of the Related Art There is known a wireless telephone capable of setting a secret mode in which voice can be transmitted at a high volume. That is, in the conventional wireless telephone, when the mode is switched from the normal mode to the secret mode, the amplification of the transmission voice signal to be supplied from the microphone to the transmission / reception circuit is increased as compared with the normal mode. Therefore, even if the transmitted voice is a low voice, the other station can receive the voice at a sufficient volume.

[0004]

However, in a conventional wireless telephone, when a confidential mode is set and a low-volume voice is transmitted, the volume level of the transmitted voice increases, but the voice received from the partner station can be heard from the speaker. Since the volume level of the voice does not change, it is anxious whether the voice is transmitted at a sufficient volume to the transmitting party, and the transmitted voice naturally tends to be loud as the psychology of the transmitter. As a result, there is a problem that the effect of the privacy mode setting is lost.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a wireless telephone in which the effect of the privacy mode setting is sufficiently exhibited.

[0005]

According to the present invention, there is provided a radio telephone, comprising: a transmission volume control means for amplifying a transmission voice signal to be supplied from a microphone to a transmission / reception circuit; and a transmission / reception circuit. Receiving volume control means for amplifying the receiving voice signal to be supplied from the speaker to the speaker (11), confidential mode setting means to be operated when transmitting in a low voice, and transmitting when the confidential mode is set. Control means for increasing the gain of the volume control means while increasing the gain of the volume control means.

In the above-mentioned radio telephone according to the present invention, when the secret mode is set, the gain of the transmission volume adjusting means increases, so that the volume level of the low-frequency transmission voice is increased and transmitted to the partner station. As the gain of the receiving sound volume adjusting means increases, the volume level of the receiving sound received from the partner station increases, and the sound is emitted from the speaker (11). When the received voice heard from the speaker (11) becomes louder, this gives a psychological effect to the sender,
The sender naturally lowers the level of the transmitted voice.
Even if the level of the transmitted voice is lowered in this way, the volume of the transmitted voice is increased and transmitted to the partner station, so that the transmitting party can receive the voice at a sufficient volume.

In a specific configuration, the radio telephone according to the present invention further includes a high-frequency cut means for removing a high-frequency component of a transmission voice signal from the microphone (1) and outputting the signal to a transmission / reception circuit (6); On / off means for turning on / off the operation of the high frequency cut means. When making a phone call in a noisy environment such as a station platform, noise is mixed in the transmitted voice input to the microphone (1). Transmitter / receiver circuit
The transmitted voice signal sent to (6) is processed by the high-frequency cut means, and the high-frequency component included in the transmitted voice signal, that is, noise is removed. Therefore, even if it is a low-voice transmission,
The transmitting party can receive a clear voice without any noise.

In another specific configuration, there is further provided a receiving sound volume setting means for variably setting the receiving sound volume level in the normal mode in which the privacy mode is not set, and the control means comprises a normal mode immediately before the privacy mode setting. The magnitude of the gain of the receiving sound volume adjusting means in the secret mode is set in accordance with the receiving sound volume level in. In this specific configuration, as the reception volume level in the normal mode immediately before setting the privacy mode is increased, the gain of the reception volume adjustment means in the subsequent privacy mode is set to be larger. Here, the receiving sound volume level in the normal mode is, for example, selected and set by the sender in advance from a plurality of predetermined sound volume levels according to the sensitivity of his / her hearing. Therefore, even in the confidential mode,
An appropriate receiving volume is set according to the sensitivity of the sender's hearing.

When the reception volume level in the normal mode immediately before the setting of the privacy mode is set to the predetermined maximum volume level of the reception volume adjustment means, the control means sets the gain of the reception volume adjustment means in the privacy mode to the normal level. Maintain the same value as in mode. Accordingly, in the secret mode, the gain of the receiving sound volume adjusting means is not set to an excessive value, whereby the saturation of the audio signal can be prevented.

[0010]

According to the radio telephone according to the present invention, there is no fear that the sender is anxious about whether or not the voice is transmitted to the other party in the secret mode in a sufficient volume. The conversation will be continued, and the effect of the secret mode setting will be sufficiently exhibited.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a PHS portable radio telephone will be specifically described with reference to the drawings. As shown in FIG. 1, the wireless telephone includes a microphone (1) and a speaker (11), and a transmission voice signal D obtained from the microphone (1) undergoes necessary processing described later, and then receives a transmission / reception circuit (6). ) Is supplied to the
Sent from (7). The reception wave received by the antenna (7) is output from the transmission / reception circuit (6) as a reception voice signal E, and after undergoing necessary processing described later, the speaker (1).
Supplied to 1).

As is well known, the transmission / reception circuit (6) comprises an audio signal processing circuit, a time division multiplexing circuit, a modulator, a demodulator, an RF filter, an IF filter, an amplifier and the like (all not shown) (for example, Nikkei). Electronics 1996.2.26 (No.
656), pages 154-155). The transmission voice signal D 'supplied to the transmission / reception circuit (6) is converted into an RF signal, and then transmitted as a transmission wave from the antenna (7) via an RF filter and an amplifier. The received wave is converted to an IF signal after a signal in a band other than the reception frequency is removed by an RF filter, and further converted to a received voice signal E via an IF filter, an amplifier, a demodulator and the like.

A transmission audio signal D obtained from the microphone (1) passes through a high-frequency cut filter (2), a preamplifier (4) and a transmission volume adjustment amplifier (5), and is transmitted and received as a processed transmission audio signal D '. It is supplied to the circuit (6). A switch (3) for turning on / off the operation is connected to the high-frequency cut filter (2). The switch (3) is turned on / off by a control signal A supplied from the outside. The cutoff frequency of the high-frequency cut filter (2) is about 2 kHz, and the transmission audio signal D is
, Only signal components in the human voice band are extracted, and noise in a higher frequency band is removed.

The transmission volume adjusting amplifier (5) is a well-known programmable amplifier capable of arbitrarily changing the gain. In this embodiment, the gain is controlled by a gain selection signal B supplied from the outside. Can be variably set to two types of 0 dB and 6 dB.

The reception voice signal E obtained from the transmission / reception circuit (6) is supplied to a reception volume control amplifier (8) and a speaker amplifier (10).
Through the speaker (11) as the processed received voice signal E '.
Supplied to The receiving volume adjusting amplifier (8) is composed of a well-known negative feedback type operational amplifier (81) and a switch (9), and has a gain of 0 dB, 6 dB, and 12 dB by a switching signal C supplied from the outside to the switch (9). It is possible to variably set three types.

Further, the radio telephone according to the present invention comprises a secret button (12) for setting a secret mode, and a volume level memory (13) for storing a reception volume level in the normal mode immediately before setting the secret mode. The privacy mode selection signal S from the privacy button (12) and the volume level data T in the volume level memory (13) are supplied to a man-machine control circuit (14) composed of a microcomputer.

In the normal mode, three kinds of receiving sound volume levels, "small", "medium" and "high", are selected by the key operation of the transmitter, so that the sound volume level is stored in a volume level memory (13). Is stored in Man-machine control circuit (14)
Supplies the switching signal C to the switch (9) of the reception volume adjustment amplifier (8) according to the volume level stored in the volume level memory (13). As a result, when the receiving sound volume level is “small”, the gain of the negative feedback type operational amplifier (81) becomes 0
switch (9) so that the gain is set to 6 dB when the reception volume level is "medium" and the gain is set to 12 dB which is the maximum volume level when the reception volume level is "high". It is switching.

In the normal mode, the switch (3) of the high-frequency cut filter (2) is turned off, and the operation of the high-frequency cut filter (2) is stopped. The gain of the transmission volume adjusting amplifier (5) is set to 0 dB.

After that, when the secret mode is selected by operating the secret button (12) and the secret mode selection signal S is supplied to the man-machine control circuit (14), the man-machine control circuit
(14) supplies a control signal A of "ON" to the switch (3) of the high-frequency cut filter (2) and a gain selection signal for increasing the gain to 6 dB for the transmission volume adjusting amplifier (5). Supply B. Also, man-machine control circuit (14)
Reads the volume level data from the volume level memory (13), increases the gain of the negative feedback operational amplifier (81) to 6 dB when the volume level is "low", and increases the gain when the volume level is "medium". Set the gain of the feedback operational amplifier (81) to 12
When the volume level is "high", a switching signal C for maintaining the gain of the negative feedback type operational amplifier (81) at 12 dB is generated and supplied to the switch (9).

As a result, the high-frequency cut filter (2) operates to remove high-frequency components (noise) contained in the transmission voice signal D and increase the gain of the transmission volume control amplifier (5). As a result, the transmission voice signal D 'containing no noise and having a sufficient signal level is supplied to the transmission / reception circuit (6). Therefore, even if the sender speaks in a low voice, the receiver can hear clear voice without noise at a sufficient volume.

At the same time, a receiving volume control amplifier
The gain of (8) is increased according to the reception volume level in the normal mode immediately before the setting of the secret mode, and when the reception volume level in the normal mode is low, the gain is medium and the reception volume level in the normal mode is medium. In the case of, the gain is set to the maximum value. As described above, since the volume of the received voice is increased by the setting of the confidential mode, as a psychological effect, the transmitter naturally becomes quiet and the effect of the confidential mode setting is sufficiently exhibited.

In order to prevent the receiving voice signal from being saturated in the receiving volume adjusting amplifier (8), when the receiving volume level in the normal mode is the maximum, the gain of the receiving volume adjusting amplifier (8) is kept unchanged at 12 dB. Although the configuration is adopted, when the gain is large as described above, there is no fear that the voice of the sender naturally increases without increasing the gain further.

Then, by operating the secret talk button (12),
When the normal mode is set again, the man-machine control circuit (1
4) turns off the switch (3) of the high-frequency cut filter (2), sets the gain of the transmission volume adjustment amplifier (5) to 0 dB, and stores the reception volume level in the normal mode before the volume level memory ( 13), and returns the gain of the reception volume adjustment amplifier (8) to the original value.

The description of the above embodiments is for the purpose of explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a wireless telephone according to the present invention.

[Explanation of symbols]

 (1) Microphone (2) High-frequency cut filter (3) Switch (5) Transmission volume control amplifier (6) Transmission / reception circuit (8) Receive volume control amplifier (11) Speaker (12) Secret talk button (13) Volume level memory (14) Man-machine control circuit

Claims (4)

[Claims] 1. A transmission / reception circuit (6) comprising a microphone (1) and a speaker (11), and transmitting a transmission voice input to the microphone (1) as a voice signal to a partner station.
A transmitting / receiving circuit (6) receives a voice signal sent from a partner station and outputs the received voice from a speaker (11) from a speaker (11). Transmission volume adjustment means for amplifying a voice signal, reception volume adjustment means for amplifying a reception voice signal to be supplied from a transmission / reception circuit (6) to a speaker (11), and operation to be performed when a voice is transmitted in a low volume A wireless communication system comprising: a confidential mode setting means; and a control means for, when the confidential mode is set, increasing the gain of the transmitting sound volume adjusting means and increasing the gain of the receiving sound volume adjusting means at the same time. Phone. 2. A high frequency cut means for removing a high frequency component of a transmission voice signal from the microphone (1) and outputting the signal to a transmitting / receiving circuit (6), and turning on / off an operation of the high frequency cut means. 2. The wireless telephone according to claim 1, further comprising an on / off means for performing the operation. 3. A reception volume setting means for variably setting a reception volume level in the normal mode in which the privacy mode is not set, wherein the control means responds to the reception volume level in the normal mode immediately before the privacy mode is set. 3. The wireless telephone according to claim 1, wherein the magnitude of the gain of the reception volume adjustment means in the secret mode is set. 4. The control means, when the reception volume level in the normal mode immediately before the privacy mode setting is set to a predetermined maximum volume level of the reception volume adjustment means, sets the gain of the reception volume adjustment means in the privacy mode to the normal level. The wireless telephone according to claim 3, wherein the value is maintained at the same value as in the mode.