JPS5924015B2 - Automotive audio equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to in-vehicle audio equipment such as car radios and car stereos, so that sounds such as alarms and warnings emitted by emergency vehicles can be sufficiently heard even when the windows of the car are completely closed. The purpose is to

These days, most cars are equipped with car coolers, and it has become more common for cars to be driven with the windows completely closed.

On the other hand, in-vehicle audio equipment is becoming more sophisticated and has higher output year by year, so if you are driving while listening to music etc. through the in-vehicle audio equipment, you will hardly be able to hear the sounds outside the car, which can help you avoid an accident. is becoming extremely difficult.

The present invention has been made to solve such problems, and no matter what condition the in-vehicle audio equipment is in use with the windows completely closed, sirens, warnings, and other sounds emitted by emergency vehicles will not be heard. This provides an excellent in-vehicle audio device that allows loud sounds to be heard completely inside the car.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An in-vehicle audio device according to the present invention will be described below with reference to drawings of an embodiment.

In the figure, 1 is an antenna, 2 is a radio receiving circuit, 3 is a magnetic head that constitutes a tape V coder, 4 is an equalizer amplifier, 5 is an amplifier circuit that amplifies the output of the radio receiving circuit 2 and the output of the equalizer amplifier 4, and 6 is a speaker connected to the output side of the amplifier circuit 5.

The antenna 1, radio receiving circuit 2, magnetic field 3, equalizer amplifier 4, and amplifier circuit 5 constitute a generally well-known acoustic circuit.

For example, 7 is a microphone attached to the outer surface of the ceiling of a car to detect sounds outside the car, 8 is a microphone amplifier that amplifies the output of the microphone 7, and 9 is a microphone that amplifies the output of the microphone 7 while the car 8 is running. A filter circuit is used to remove the output caused by the wind pressure or other small noises that are received, and 10 is a level at which the sound is detected when the output of the microphone amplifier 8 that has passed through the filter circuit 9 exceeds a predetermined level. A detection circuit 11 is a holding circuit 12 for holding the output of the level detection circuit 10 for several minutes.
13 is a mixing circuit that mixes the output 711 of the microphone amplifier 8 which has passed through the switch circuit 12 with the signal from the audio circuit.

Note that the mixing circuit 13 includes an attenuator that is controlled by the output of the holding circuit 11 and attenuates the output of the acoustic circuit.

In the above embodiment, under normal conditions, the signal or magnetic field received by the antenna 1 and processed by the radio receiving circuit 2 is
The signal reproduced by the rad 3 and processed by the equalizer amplifier 4 is applied to the amplifier circuit 5 via the mixing circuit 13.

Noise generated outside the vehicle is electrically detected by a microphone 7, amplified by a microphone amplifier 8, and applied to a filter circuit 9 and a switch circuit 12.

Now, if the noise outside the vehicle is only wind pressure or other small noises, this will be greatly attenuated by the filter circuit 9 and the signal applied to the novel detection circuit 10 will be extremely small.

Therefore, no output appears in the level detection circuit 10, and no output appears in the holding circuit 11, so the switch circuit 12 is in an OFF state, and the output of the microphone amplifier 8 is not applied to the mixing circuit 13.

As a result, in this state, only the radio signal received by the antenna 1 or the signal reproduced by the magnetic head 3 can be accurately received.

Suppose that the noise outside the vehicle includes relatively loud sounds such as horns, sirens and warnings emitted by emergency vehicles.

In this case, the level of the signal obtained by the microphone amplifier 8 exceeds a predetermined value, and a constant output appears from the level detection circuit 10J.

Therefore, a predetermined output also appears from the holding circuit 11 for a certain period of time, and the switch circuit 12 is fully turned on during this period.

Therefore, the signal amplified by the microphone amplifier 8 is applied to the mixing circuit 13 through the switch circuit 12, and in this case, in addition to the radio signal and the signal reproduced by the magnetic head 3, the signal obtained by the microphone 7 is applied to the mixing circuit 13 through the switch circuit 12. The signals will be applied to the amplifier circuit 5 at the same time.

As a result, the siren and alarm sounds can be easily heard through the speaker 6.

Note that the mixing circuit 13 includes the holding circuit 1 as described above.
Since it is equipped with an attenuator that is controlled by the output of the holding circuit 11 and attenuates the output of the acoustic circuit, when the output from the holding circuit 11 appears, the radio signal or the signal reproduced by the magnetic head 3 is attenuated, and the signal obtained by the microphone 7 is attenuated. Only the signal will appear at the output end of the mixing circuit 13, and in this case it can be heard more accurately than the siren or alarm sound.

As is clear from the above embodiments, the in-vehicle audio equipment of the present invention is configured such that when the noise outside the vehicle becomes louder than a predetermined level, the noise is automatically emitted from the speaker so that it can be easily heard. Even when the windows are closed and audio equipment is used, abnormally loud noises outside the vehicle can be easily detected, and accidents can be easily prevented.

According to the present invention, the output of the microphone for detecting noise outside the vehicle is mixed with the signal of the acoustic circuit, so the overall configuration is extremely simple and is extremely advantageous in practice.

[Brief explanation of the drawing]

The figure is a schematic electrical connection diagram of an embodiment of the in-vehicle audio equipment of the present invention. 1... Antenna, 2... Radio receiving circuit, 3... Song/magnetic head, 4... Equalizer amplifier, 5... Amplification circuit, 6... ... Speaker, 7 ... Microphone, 8 ... Microphone amplifier, 9 ... Filter circuit, 10 ...
...Level detection circuit, 11...Holding circuit,
12... Switch circuit, 13... Vexing circuit.

Claims (1)

[Claims] 1. A microphone for detecting sounds outside the vehicle interior, a switch circuit that is turned on and off depending on the output level of this microphone, and an output of the microphone obtained through this switch circuit that is transmitted to a radio receiving circuit and a tape nocoder. Equipped with a mixing circuit that mixes with the acoustic circuit of
A vehicle-mounted audio device characterized in that the sound is connected to the output side of the acoustic circuit and is audible from the fζ speaker only when the sound outside the vehicle exceeds a predetermined level.