JPH09247245A - Telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a proper transmission sound volume even when a speech is made in an open or closed flap state by selecting a gain of a sound amplifier based on a control signal obtained through the detection of an open or closed flap. SOLUTION: The telephone set has a sound amplifier 11 whose gain is adjustable, an open/close flap plate to protect an operation section, and an open or closed flap state detection circuit 9 detecting an open or closed flap. The gain of the sound amplifier 11 is changed by a control signal outputted from the open or closed flap state detection circuit 9. The open or closed flap state detection circuit 9 is easily realized by a switch such as a mechanical switch of a reed switch utilizing magnetism or an electric switch. Through the constitution above, even when a speech is made while keeping the flap closing without opening the flap simply, the gain of the sound amplifier 11 is selected to be an optimum gain for the closed flap. Thus, the same transmission sound volume as the case of a speech with the opened flap is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone that transmits and receives voice by using radio.

[0002]

2. Description of the Related Art FIG. 3 is an external view of a telephone that transmits and receives voice using a radio such as a cordless telephone, and is provided with a plate-like flap (cover) that protects an operating portion. FIG. 4 is a block diagram of a conventional audio circuit.

In FIG. 3, (a) shows a state in which the flap is opened for use, and (b) shows a state in which the flap is closed. In FIGS. 3 (a) and 3 (b), 1 is a telephone body, 3
Is a plate-like flap that can be opened and closed, 4 is a microphone, 5 is a call switch, and 6 is a redial switch. In FIG. 3A, 2 is an operation unit. In FIG. 4, 4 is a microphone (MIC), and 8 is an audio amplifier for amplifying an audio signal from the microphone 4.

In the telephone configured as described above, it is normally used in the state where the flap shown in FIG. 3 (a) is opened. In this case, the flap 3 acts as a reflector for the sound emitted from the user's mouth. Even when the flap is closed as shown in FIG. 3B, the microphone 4 is exposed, and the call switch 5 can be used to receive a call and the redial switch 6 can be used to perform a call, and the operation can be performed. An incoming call can be made simply by omitting the operation of opening the flap 3 without the operation of any part.

FIG. 4 is a block diagram of a conventional voice circuit of a telephone. The voice input to the microphone 4 is amplified by a voice amplifier 8 with a predetermined gain and output as a transmission voice signal.

[0006]

However, in the above-mentioned conventional structure, when the flap is opened, the flap acts as a reflector for the sound uttered from the mouth, so that the sound pressure of the sound input to the microphone causes the flap to operate. It is higher than when closed. The gain of the voice amplifier 8 is determined to be optimal for the sound pressure input to the microphone when the flap is opened, so if you make a call with the flap closed, compared to when you open the flap and talk There was a problem that the volume was low and it was transmitted to the other party.

It is an object of the present invention to provide a telephone which can obtain an appropriate transmission volume regardless of whether the call is made with the flap open or closed.

[0008]

In order to solve the above problems, the present invention has a flap open / close detection circuit, and a control signal output from the flap open / close detection circuit interlocks with the opening / closing of the flap to produce a voice. The gain of the amplifier is automatically switched.

With this configuration, it is possible to obtain a telephone which can obtain an appropriate transmission volume regardless of whether the call is made with the flap open or closed.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a voice amplifier capable of switching the gain, a plate-like flap that can be opened / closed for protecting the operating portion, and an opening / closing for detecting the opening / closing of the flap. It has a detection circuit and is configured to switch the gain of the audio amplifier according to the control signal output from the open / close detection circuit. With this configuration, the audio amplifier can be used even when the call is kept closed without opening the flap. Since the gain is switched to the optimum gain when the flap is closed, there is an effect that the same transmission volume as when the call is made with the flap open can be obtained.

An embodiment of the present invention will be described below. (Embodiment 1) FIG. 1 is a block diagram of a voice switching circuit of a telephone according to an embodiment of the present invention, and FIG. 2 shows waveforms of respective parts in FIG. The external appearance of the telephone in this embodiment is the same as that shown in FIG. 3 described above, and detailed description thereof will be omitted.

In FIG. 1, reference numeral 9 denotes a flap open / close detection circuit for detecting the open / closed state of the flap 3, and the flap open / close detection circuit 9 is a mechanical switch, a magnetic switch such as a reed switch, or an electronic switch. It can be easily realized with a simple switch. Reference numeral 10 is a microphone (MIC) for converting an audio signal into an electric signal, and 11 is an audio amplifier capable of varying the gain in two steps by an external control signal.

FIG. 2 is a waveform diagram of each part in FIG.
Reference symbol a denotes a voice signal output from the microphone 10, b is a control signal output from the flap open / close detection circuit 9, and c is a transmission voice signal output from the voice amplifier 11. d represents the gain of the audio amplifier 11. e and f represent the gain of the audio amplifier 11, and have a relation of f> e.

Further, g indicates a section in which the flap 3 is open for talking, and h indicates a section in which the flap 3 is closed for talking.

The telephone configured as described above will be described below with reference to the block diagram of FIG. 1 and the waveform diagram of FIG. In the following description, it is assumed that the sound pressure of the voice uttered by the speaker's mouth is constant.

First, when a call is made by opening the flap 3, a voice signal having a larger amplitude than that in the case of making a call by closing the flap 3 as shown in FIG.
Output from Further, a control signal indicating that the flap 3 is open is output from the flap open / close detection circuit 9 as shown in b of FIG. The audio amplifier 11 operates according to the control signal from the flap open / close detection circuit 9 with the gain shown in FIG. 2e which is optimally determined for the audio signal when the flap 3 is opened, and the transmission shown in c in FIG. Output an audio signal.

On the other hand, when a call is made with the flap 3 closed, the flap 3 does not act as a reflector of the voice, so that the amplitude of the voice signal output from the microphone 10 is average as shown in FIG. It will be smaller than when opening the flap 3 and talking. However, at this time, the flap open / close detection circuit 9 outputs a control signal indicating that the flap 3 is closed as shown in b of FIG. 2 and is input to the audio amplifier 11, so that the audio amplifier 11 turns on the flap 3. The voice signal when closed is operated with the gain determined optimally as shown in FIG. 2f, and the transmission voice signal shown as c in FIG. .

Audio amplifier 11 when the flap 3 is opened and closed
The difference in the gain between the shape of the phone body, the shape of the flap 3,
Also, an appropriate value is determined in consideration of the angle when the flap 3 is opened.

As described above, in the present embodiment, the gain of the voice amplifier 11 is automatically switched by the control signal output from the flap open / close detection circuit 9 for detecting the open / close of the flap 3 in association with the flap open / close. As a result, an appropriate transmission volume can be obtained regardless of whether the call is made with the flap open or closed.

In a telephone that converts voice into digital data by a coding device (CODEC) and transmits voice by transmitting digital data, the CODEC is used.
It is possible to switch the internal audio amplifier gain by an external control signal. In this case, an external audio amplifier having a normal configuration can be used, and it is not necessary to use an audio amplifier whose gain is switched in two stages. .

[0021]

As described above, according to the present invention, even when a simple call is made with the flap closed, the gain of the voice amplifier circuit is optimally switched to the sound pressure when the call is made with the flap closed. , You can talk with the same transmission volume as when you open the flap and talk.

[Brief description of drawings]

FIG. 1 is a block diagram of a voice switching circuit of a telephone in an embodiment of the invention.

FIG. 2 is a waveform chart of each part of the voice switching circuit of the telephone according to the embodiment of the present invention.

FIG. 3 is an external view of a conventional telephone having a flap.

FIG. 4 is a block diagram of a voice circuit of a conventional telephone.

[Explanation of symbols]

 9 Flap open / close detection circuit 10 Microphone 11 Audio amplifier

Claims (3)

[Claims] 1. An audio amplifier capable of switching gain, an openable / closable plate-like flap for protecting an operating portion, and an open / close detection circuit for detecting the opening / closing of the flap, which are output from the open / close detection circuit. A telephone characterized in that the gain of the voice amplifier is switched by a control signal. 2. The audio amplifier is capable of switching the gain in two stages, and when the open / close detection circuit detects the opening of the flap, the gain of the audio amplifier is lowered by a control signal indicating the opening. The telephone set according to item 1. 3. A voice amplifier is provided in an encoding device for converting voice into digital data, and the gain of the voice amplifier in the encoding device is switched by a control signal from an open / close detection circuit. The telephone set according to item 1.