JPH04270516A - Audio equipment for vehicle - Google Patents

Abstract

PURPOSE:To always obtain a proper dynamic range and to allow the user to easily listen to a weak sound from the audio equipment regardless of the acoustic state in a cabin such as a position of a sound volume knob and a degree of a noise level. CONSTITUTION:A compressor 2 compresses a dynamic range of an input signal from a signal source 1. A sound volume position detection device 7 detects the sound volume position of a sound volume control 3 and its detection signal is inputted to a control circuit 8. The control circuit 8 controls the compressor 2 to increase the compression of the dynamic range at a region where an input signal level is small as the sound volume position of the sound volume control 3 indicates a small sound volume. As a result, when a sound with a small input signal level is hardly heard, an output signal level from the compressor 3 is increased and a weak sound becomes easy to listen.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in vehicle audio equipment, and more particularly to measures for making it easier to hear even small sounds with low signal levels inside a vehicle interior.

0002

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Laid-Open No. 61-164311, a vehicle audio system that takes ambient noise into consideration has been used to change the acoustic signal level of an acoustic source according to the ambient noise level. A device is known in which the volume from a speaker is automatically adjusted depending on the surrounding noise.

0003

By the way, in recent years, the dynamic range of audio equipment has exceeded 90 dB, and the output level of the minimum sound is an extremely small value. For this reason,
In particular, when the volume knob of the audio device is turned down, or when the surrounding noise of the vehicle or the noise generated by the vehicle itself is large, it is difficult to hear the minimum sound.

[0004] Therefore, for example, it may be possible to compress the dynamic range of the audio device in advance and raise the output level of the lowest sound to some extent, but this idea suggests that the volume knob should be set to the loudest position. In some cases, or when the noise level of the vehicle is relatively low, there arises a problem that although the device has a function of outputting a small sound with a lower output level, the function cannot be effectively exerted.

[0005] The present invention has been made in view of the above points, and its purpose is to control the dynamic range to be variable as appropriate without fixing it, so that the dynamic range can be adjusted at all times regardless of the position of the volume knob or the level of noise. The objective is to obtain an appropriate dynamic range and make it easier to hear the smallest sound of an audio device.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention variably controls the dynamic range of an audio device depending on the acoustic condition inside the vehicle interior.

In other words, the specific solution of the present invention includes compression means for reducing the difference between the maximum sound output level and the minimum sound output level of the signal source, and the compression means changes the output level of small sounds. The target is vehicle audio equipment. and an acoustic condition detecting means for detecting the acoustic condition in the vehicle interior by, for example, the volume position of the audio device or the noise level of the vehicle; The configuration includes a compression amount changing means for changing the compression amount.

[0008]

[Operation] With the above structure, the compression means is controlled according to the acoustic condition in the vehicle interior, so that, for example, when the volume knob of the audio device is turned down or when the noise level of the vehicle is high, The situation is such that it is difficult to hear the lowest sounds, but since the amount of compression of the dynamic range of the audio equipment is increased,
The output level of the minimum sound increases accordingly, making it easier to hear the minimum sound. Conversely, if the volume knob is in the high volume position or the vehicle's noise level is low,
In situations where it is easy to hear low sounds, the amount of compression of the dynamic range of the audio device is reduced, so the output level of the smallest sound is also lowered, and the sound is improved while ensuring that the smallest sound is easy to hear. The intended performance of the device is effectively demonstrated.

[0009]

As explained above, according to the vehicle audio system of the present invention, the dynamic range of the audio system can be adjusted according to the acoustic conditions in the vehicle interior, such as the position of the volume knob of the audio system and the noise level of the vehicle. Because it is variably controlled, it is possible to always obtain the appropriate dynamic range regardless of changes in the acoustic conditions in the vehicle interior.Therefore, while making good use of the minimum sound output function that the audio system originally has, it is possible to always obtain the minimum sound. This has the effect of making it easier to listen to.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a vehicle audio system according to the present invention. In the same figure, 1 is a CD or DAT
2 is a second signal source from the signal source 1.
The compressor 2 is a compression means for reducing the difference between the maximum sound output level and the minimum sound output level of the input signal, that is, the dynamic range, as shown by the solid line in the figure, and the compressor 2 changes the output level of the minimum sound. This configuration changes the dynamic range.

Further, numeral 3 is a volume adjustment mechanism that receives the signal from the compressor 2, 4 is an amplifier that amplifies the signal adjusted by the volume adjustment mechanism 4, and 5 is a volume control mechanism that receives the signal amplified by the amplifier 4 to This is a speaker that radiates sound into the room.

Reference numeral 7 denotes a volume position detection mechanism as an acoustic state detection means for detecting the volume position of the signal source 1 adjusted by the volume adjustment mechanism 3 to detect the acoustic state in the vehicle interior; 8 indicates the compressor 2; A control circuit for controlling the amount of compression of the dynamic range of
It functions as a compression amount changing means that changes the amount of compression of the dynamic range according to the volume position as the acoustic state in the vehicle interior detected by the volume position detection mechanism 7, and specifically, as shown in FIG. In a region where the level of the input signal from signal source 1 is relatively low below the Lo value, the smaller the volume of the signal source is, the more the dynamic range is compressed than at the louder volume position. The compressor 2 is modified to increase the level of the output signal from the compressor 2.

Therefore, in the above embodiment, the lower the volume position of the volume adjustment mechanism 3 is, that is, the harder it is to hear low sounds, the more the dynamic range compression amount is changed, and the lower the signal level is, the lower the signal level is. In this region, the signal level is increased as shown by the broken line in FIG. 3, making it easier to hear small sounds.

Furthermore, when the volume control mechanism 3 is at a high volume position and low sounds are relatively audible, the amount of compression of the dynamic range is small and the signal level is approximately equal to the signal value shown by the solid line in FIG. Since they are the same value, the signal source 1 can effectively demonstrate its functions without substantially compressing its inherent dynamic range while easily listening to small sounds.

FIG. 4 shows a second embodiment of the present invention.In the above embodiment, instead of changing the dynamic range according to the volume position of the volume control mechanism 3, the dynamic range is changed according to the vehicle speed. be.

That is, in FIG. 4, reference numeral 10 denotes a vehicle speed sensor, which constitutes an acoustic condition detecting means for detecting the noise level of the vehicle based on the vehicle speed and detecting the acoustic condition inside the vehicle interior. Reference numeral 11 denotes a control circuit for controlling the compression amount of the dynamic range of the compressor 2, and the control circuit 11 serves as a compression amount changing means for changing the compression amount of the dynamic range according to the vehicle speed detected by the vehicle speed sensor 10. Specifically, as shown in Figure 5,
L1 where the level of the input signal from signal source 1 is relatively low
In the region below the value of It is configured to increase the

Therefore, in this embodiment as well, as shown by the broken line in FIG. 6, in the signal portion where the signal level of the signal source 1 is below L1, the higher the noise level becomes as the vehicle speed increases, the higher the signal portion becomes. Since the signal level is changed high, it becomes easier to hear small sounds. Further, when the vehicle speed is low and low noise is relatively audible, the signal level is almost the same as the signal value shown by the solid line, so the large dynamic range inherent in the signal source 1 can be effectively utilized.

In the second embodiment, the noise level is detected based on the vehicle speed, but the noise level may also be detected using the engine speed, or may be detected by placing a noise sensor inside the vehicle.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a block configuration of a vehicle audio device.

FIG. 2 is an explanatory diagram of the amount of dynamic range compression with respect to the level of volume.

FIG. 3 is a diagram showing an explanation of the operation.

FIG. 4 is a diagram showing a block configuration of a vehicle audio device showing a second embodiment.

FIG. 5 is an explanatory diagram of the amount of dynamic range compression with respect to vehicle speed.

FIG. 6 is a diagram showing an explanation of the operation of the second embodiment.

[Explanation of symbols]

1 Signal source 2 Compressor (compression means) 3
Volume adjustment mechanism 5 speaker

Claims (3)

[Claims] 1. A vehicular audio device comprising compression means for reducing the difference between a maximum sound output level and a minimum sound output level of a signal source, the compression means changing the output level of small sounds, comprising: The present invention is characterized by comprising an acoustic state detection means for detecting an acoustic state inside the vehicle interior, and a compression amount changing means for changing the compression amount of the compression means according to the acoustic state inside the vehicle interior detected by the acoustic state detection means. A vehicle audio system for 2. The acoustic state detection means detects the volume position of the signal source, and the compression amount changing means changes the sound output level when the volume of the signal source is low compared to when the volume is high. The vehicle acoustic device according to claim 1, wherein the amount of compression is changed by a large amount. 3. The acoustic state detection means detects the noise level of the vehicle, and the compression amount changing means changes the sound output level when the noise level of the vehicle is high compared to when the noise level is low. The vehicle acoustic device according to claim 1, wherein the amount of compression is changed by a large amount.