JPH0787586A - Sound volume control for audio device for automobile - Google Patents

Abstract

PURPOSE:To optimally control a sound volume level free from unnatural feeling to a human hearing sensation by automatically adjusting the sound volume level corresponding to the noise which changes in rough proportion to the speed of the automobile. CONSTITUTION:When the automobile runs and the speed is increased, the output voltage (audio level control signal) E of an F.V converter 22 is proportionally increased with the increase of automobile speed information (corresponding to engine speed Q) from an ignition coil 21. At this time, as an electronic volume circuit 22 adds an output signal K corresponding to a sound volume level output signal to a system output C from a car radio unit 10, the sound volume level from a speaker 15 is increased in rough proportion to the increased portion of the speed. But, when the car is decelerated, the sound volume level from the speaker 15 is decreased in rough proportion to the decreased portion of speed. Consequently, the sound volume level is controlled automatically and optimally to the increase/decrease of the noise which changes in rough proportion to the speed of the automobile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a volume control device for a car audio device such as a car radio, car stereo, car television, etc., and more particularly to a car for automatically controlling the volume according to the noise in the car. The present invention relates to a volume control device for an audio device.

[0002]

2. Description of the Related Art Generally, for volume adjustment of an audio device such as a car radio, an arbitrary level is selected by a manual volume switch. Therefore, even if the volume is adjusted during idling, if the noise inside the vehicle increases during driving, the volume level of the audio equipment such as the car radio will be insufficient and the volume level will be increased again. On the contrary, even if the volume is adjusted while driving, the volume level of the audio equipment such as a car radio feels excessive when the car is stopped due to signal waiting etc., and the volume is lowered again. The volume adjustment had to be done frequently, and the volume had to be manually adjusted frequently according to the increase or decrease of the noise in the vehicle, and the volume adjustment operation was extremely troublesome.

As a conventional technical means for solving such a technical problem, for example, a vehicle interior noise is measured at a break of information from an audio device such as a car radio, and the sound of the car radio or the like is measured based on the measurement result. It has been proposed to automatically control the volume level of the device.

[0004]

However, in such a type, it is originally difficult to accurately measure the noise level in the vehicle, so that the volume level of an audio device such as a car radio changes unnaturally. There was a risk that it would increase or decrease and give a feeling of strangeness.

The present invention has been made to solve the above technical problems, and it is possible to optimally control a volume level according to a noise level in a vehicle without giving a sense of discomfort to human hearing. The present invention provides a sound volume control device for an automobile audio device.

[0006]

That is, the inventor of the present application has found that the vehicle interior noise increases or decreases substantially in proportion to the vehicle speed of the vehicle, and as shown in FIG. 1, vehicle speed detection means for detecting vehicle speed information A of the vehicle. 1, a control signal generating means 2 for generating a volume level control signal B corresponding to the vehicle speed information A detected by the vehicle speed detecting means 1, and a volume level control signal B generated by the control signal generating means 2. Volume level changing means 3 for changing the volume level of the audio device 4 for a car based on
The present invention has been devised that includes the following.

In such technical means, the present invention is intended not only for car radios but also for general car audio devices such as car stereos, car televisions, and radio telephones.

The vehicle speed detecting means 1 may be appropriately selected as long as it can detect the vehicle speed information A. For example, an ignition coil detects an ignition pulse (corresponding to the engine speed). Alternatively, a pickup coil may be installed near the alternator to detect the leakage magnetic flux of the alternator (proportional to the engine speed), or the ripple of the alternator superimposed on the battery power line. The minutes may be detected, or the vehicle speed signal may be detected directly from the speedometer signal.

Further, the control signal generating means 2 may be constructed so as to generate the volume level control signal B which is substantially proportional to the normal vehicle speed information A, but is not necessarily limited to this, and the human hearing The vehicle speed information A may be converted into the volume level control signal B based on a characteristic curve in consideration of characteristics.

Furthermore, the volume level varying means 3 may be appropriately selected as long as it changes the volume level according to the volume level control signal B. In this case, the volume level may be uniquely set according to the volume level control signal, but considering that humans have different senses of volume, the volume level according to the volume level control signal is slightly different. It is preferable to provide a fine adjustment mechanism for adjustment.

[0011]

According to the above-mentioned technical means, when the vehicle speed detecting means 1 detects the vehicle speed information A of the automobile, the control signal generating means 2 produces a volume corresponding to the vehicle speed information A detected by the vehicle speed detecting means 1. The level control signal B is generated. Then, the volume level varying means 3 changes the volume level of the automobile acoustic apparatus 4 based on the volume level control signal B generated by the control signal generating means 2. At this time, the vehicle speed information A
Is approximately proportional to the in-vehicle noise level, so that the volume level of the vehicle audio system 4 can be changed at any time in accordance with the in-vehicle noise level.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the accompanying drawings. Example 1 FIG. 2 shows Example 1 of a car radio system to which the present invention is applied. In the figure, reference numeral 10 is a car radio unit mounted in an automobile, and is connected to a battery power source 11 according to an ON operation of an ignition switch 12. A speaker 15 is connected to the car radio unit 10 via a power amplifier 14, and the volume of the car radio is manually adjusted by adjusting the volume switch 13.

Further, the car radio system according to this embodiment is provided with a volume control device for automatically controlling the volume level according to the increase or decrease of the vehicle speed. In this embodiment, as the vehicle speed detector, an ignition coil 21 for generating a high voltage necessary to fly an electric spark to the spark plug 16 is used, and an ignition pulse flowing through the primary side of the ignition coil 21 is a vehicle speed detector. It is detected as information (corresponding to the engine speed Q).

Further, the vehicle speed information (corresponding to the engine speed Q) detected by the ignition coil 21 changes from the idling value Qa to the maximum value Qmax. This vehicle speed information is F / V converter (frequency-voltage conversion). 2) and is converted into an output voltage (volume level control signal) E (Ea to Emax) proportional to the vehicle speed information (corresponding to the engine speed Q), as shown in FIG. The proportional coefficient of the F / V converter 22 can be appropriately changed by an adjusting knob (not shown).

Further, an electronic volume circuit 23 is interposed between the car radio unit 10 and the power amplifier 14, and the electronic volume circuit 23 is connected from the F / V converter 22 as shown in FIG. Output voltage E (E
The output voltage K (0 to Kmax) proportional to a to Emax) is added to the system output C from the car radio unit 10 and output. The electronic volume circuit 23
The proportional coefficient of the output voltage K can be changed appropriately with an adjustment knob (not shown).

Next, the operation of the volume control device for the car radio according to this embodiment will be described. Assuming that the vehicle speed is increasing while the vehicle is running,
As the vehicle speed information (corresponding to the engine speed Q) from the ignition coil 21 increases, the output voltage (volume level control signal) E of the F / V converter 22 increases proportionally. At this time, since the electronic volume circuit 23 adds the output voltage K according to the volume level control signal to the system output C from the car radio unit 10, the speaker 1
The volume level from 5 increases substantially in proportion to the increase in vehicle speed. When the vehicle speed is decreasing, conversely to the above, the volume level from the speaker 15 decreases substantially in proportion to the decrease in the vehicle speed.

In such an operation process, the volume level of the car radio automatically increases or decreases in proportion to the increase or decrease in the vehicle speed, but it has been experimentally found that the noise in the vehicle is substantially proportional to the vehicle speed of the automobile. From what has been confirmed, it can be said that the volume level of the car radio changes according to the increase or decrease of the noise in the vehicle. Actually, when several tens of test subjects were put on a car equipped with the car radio system according to the example and each experienced a change in the volume level of the car radio, the volume of the car radio became difficult to hear on the way, or conversely. , There is no situation that I feel extremely noisy on the way, and I do not have to worry about the noise inside the car so much and there is no discomfort that the volume of the car radio changes suddenly,
It was confirmed that it would be possible to continue listening to the sound of the car radio. Such a phenomenon is caused by the fact that the increase / decrease in the noise level in the vehicle and the increase / decrease in the volume level substantially match, and furthermore, when the human hearing suppresses the noise, suppression is also applied to the normal sound. It seems to do.

Second Embodiment FIG. 5 shows a second embodiment of a volume control device for a car radio to which the present invention is applied. In the figure, the basic configuration of the car radio system is substantially the same as that of the first embodiment, but the volume control device of the car radio is different from that of the first embodiment and the alternator 3 is used.
The rotor rotation speed of 1 (corresponding to the engine rotation speed) is detected as vehicle speed information, and the volume level of the car radio is controlled. The same components as those of the first embodiment are designated by the same reference numerals as those of the first embodiment, and the detailed description thereof is omitted here.

In this embodiment, the alternator 31
A pickup coil (in this embodiment, a coil having a coil wound around an iron core is used) 32 is attached in the vicinity of, and the alternator 31 is attached by the pickup coil 32.
The rotational speed Q'of the rotor (corresponding to the leakage magnetic flux of the alternator 31) is detected. The rotor rotation speed Q ′ of the alternator 31 detected by the pickup coil 32 is input to the F / V converter 33,
It is converted into an output voltage (volume level control signal) E that is proportional to the rotor speed Q ′ of the alternator 31. Further, the output voltage E from the F / V converter 33 is input to the electronic volume circuit 34, and the output voltage K proportional to the output voltage E from the F / V converter 33 is supplied to the car radio unit 10 as in the first embodiment. It is designed to be added to the system output C from and output (see FIG. 4).

Therefore, according to the volume control device for the car radio of this embodiment, the volume level of the car radio changes in accordance with the increase / decrease in the vehicle speed of the automobile. Not only is the volume level controlled according to the increase / decrease of the noise in the vehicle, but in this embodiment, unlike the first embodiment, it can be applied to a diesel vehicle without an ignition device.

[0021]

As described above, according to the present invention, the volume level of the automobile audio system is automatically adjusted in accordance with the increase / decrease in the in-vehicle noise that changes substantially in proportion to the vehicle speed. Therefore, when the vehicle is traveling, it is of course unnecessary to manually adjust the volume level according to the increase or decrease of the noise in the vehicle, and the SN ratio is good and the human hearing is hardly affected by the noise in the vehicle. It is possible to realize optimal volume level control without any discomfort.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a volume control device for an automobile audio system according to the present invention.

FIG. 2 is an explanatory diagram showing a first embodiment of a volume control device for a car radio to which the present invention is applied.

FIG. 3 is a graph showing the characteristics of the FV converter according to the first embodiment.

FIG. 4 is a graph showing the characteristics of the electronic volume circuit according to the first embodiment.

FIG. 5 is an explanatory diagram showing a second embodiment of a volume control device for a car radio to which the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vehicle speed detection means, 2 ... Control signal generation means, 3 ... Volume level varying means, 4 ... Car audio device, A ... Vehicle speed information,
B ... Volume level control signal

Claims (1)

[Claims] 1. A vehicle speed detecting means (1) for detecting vehicle speed information (A) of a vehicle, and a volume level control signal (B) according to the vehicle speed information (A) detected by the vehicle speed detecting means (1).
And a volume level control signal (B) generated by the control signal generating means (2).
And a sound volume level changing means (3) for changing the sound volume level of the vehicle audio system (4) based on the above.