JPS5823987B2 - telephone recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a telephone recording device for recording telephone calls.

With call recorders currently installed in answering machines and the like, the voice of the other party is significantly lower than the voice of the other party due to call loss in the telephone line.

Therefore, even if the conversation is recorded as is, it is often difficult to understand the conversation.

In addition, as a countermeasure against this problem, some devices have an AGC circuit, but the effect thereof is small.

The present invention aims to eliminate this difference in call level and provide an intelligible recording device, and an embodiment thereof will be described below.

FIG. 1 shows the relationship with the other party, where 1 is the telephone of the other party and 2 is the telephone exchange.

Reference numeral 3 designates our telephone, to which a telephone recording device 4 is connected, and a microphone 5 is installed very close to the telephone 3.

FIG. 2 shows the details of the device 4, in which 6 is a terminal board for the telephone 3, 7 is an audio comparator, 8 is an amplifier for amplifying the microphone output, and 9 is for amplifying the signal to be applied to the tape recorder 10. It is a amplifier that does this.

Next, the operation will be explained.

First, when we make a call using the telephone 3, a signal with an extremely high audio level as shown at a in FIG.

This signal is also applied to a comparator 7. The speech sound is detected by a microphone 5, amplified by an amplifier 8, and applied to the comparator 7 as a signal shown in FIG.

The comparator 7 compares the levels and phases of the two input signals, and when the output of the amplifier 8 reaches a certain level or higher, it adds a predetermined loss and sends it to the amplifier 9, where it is output by the tape recorder 10. Make a recording.

Conversely, calls from the other party are sent from the telephone 1 to the telephone 3 via the terminal board 6.

This signal is illustrated by b in FIG. 3A.

A signal is also applied from the terminal board 6 to the comparator 7, but since there is no output from the microphone 5 during this period, the signal is directly applied to the amplifier 9, amplified, and recorded on the tape recorder 10.

Therefore, as shown in FIG. 3C, the telephone calls from telephones 1 and 3 can be recorded on tape recorder 10 at approximately the same level.

As is clear from the above embodiments, according to the present invention, since only the level of the telephone call signal is attenuated, the content of the telephone conversation can be clearly recorded.

In addition, installation work is easy because the microphone can be installed without any modification to the telephone (simply by placing the microphone near the telephone).

[Brief explanation of drawings]

FIG. 1 is a block diagram of a telephone recording device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the detailed configuration of its main parts, and FIG. 3 is a signal waveform diagram thereof. 3...Telephone, 5...Microphone,
7... Comparator, 10... Tape recorder.

Claims (1)

[Claims] 1. A microphone is provided in the vicinity of the telephone, a recording means is connected to the telephone and records the sound of a call, and the level of the recording signal applied to the recording means is suppressed in accordance with the level of the audio signal detected by the microphone. A telephone recording device characterized by comprising means.