JPH04138945A - On-vehicle audio device - Google Patents

Abstract

PURPOSE:To prevent occurrence of a trouble in which a driver is difficult to hear music during the use of a blower fan by controlling an electronic volume according to a blast amount of a blower fan and a state to switch internal/ external air through the volume regulating function of a control part. CONSTITUTION:A cassette is charged in a cassette deck 1 and music sounds through speakers 6A-6D at a proper volume. In this case, when a volume is stored in the internal memory of a microcomputer 3, it is first detected by the microcomputer 3 whether a voltage detecting signal Sv is inputted from a motor voltage detecting circuit 7, and it is decided whether a blower fan is turned ON. In which case, when it is turned ON, it is decided by means of an output from an internal/external air change-over detecting switch 11 whether it is an internal air circulating state and decided by means of the voltage detecting signal Sv whether a motor voltage is below eight volt (V). Based on the decision results, a volume generated through the speaker 6A-6D is controlled so that a volume is adjusted to a value having a level increased from a reference volume by a given amount.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle-mounted audio device, and particularly to a vehicle-mounted audio device having a so-called electronic volume.

[Background technology]

In recent years, in-vehicle audio equipment (car audio) has become more multi-functional due to improvements in the performance of electronic components, accuracy and performance of mechanical parts, and to meet the needs of users who demand luxury and high performance. , and are becoming more sophisticated and high-performance. For example, instead of a traditional volume (usually an externally operable potentiometer) for volume adjustment,
Many products are now equipped with an electronic volume that can be operated with one touch in conjunction with a microcomputer.

[Problem to be solved by the invention]

However, when using an air conditioner in the summer or a heater in the winter, it is necessary to drive the air conditioning blower fan at an appropriate rotation speed depending on the temperature. The sound of the wind increases the noise level, making it difficult to listen to music, etc.
Further, as the amount of air blown by the blower fan changes, the level of noise caused by the rotation sound of the blower fan motor and the sound of the wind also changes. Therefore, in the past, the passenger had to manually adjust the volume to an appropriate level each time, which was troublesome and time-consuming.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art, and its purpose is to provide a system that is not significantly influenced by the indoor air conditioning condition of the vehicle, and without the need for the passenger to perform any volume correction operation. To provide an in-vehicle audio device that allows you to always listen to music, etc. at an appropriate volume.

[Means to solve the problem]

The present invention provides an acoustic source, an electronic volume that inputs an audio signal output from the acoustic source, increases or decreases the level of the audio signal according to an external command, and outputs the level to an audio output section, and a control that controls the electronic volume. It has a section. Then, an air volume detection means for detecting the air flow rate of the air conditioning blower fan of the vehicle and an inside/outside air switching detection means for detecting switching between inside and outside air are connected to this control part, and the control part The device is configured to have a volume adjustment function that controls the electronic volume according to the output signals from both detection means. This aims to achieve the above-mentioned purpose.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the embodiment shown in FIG. 1, a cassette deck 1 as a sound source and analog stereo audio signals rR'' and rL= reproduced by this cassette deck 1 are input, and the level of the audio signals will be described later. An electronic volume 2 that increases or decreases according to commands from a microcomputer and outputs to the audio output unit 4, and a microcomputer (microcomputer) as a control unit that controls the electronic volume 2.
3.

Specifically, the electronic volume 2 receives rCE (Chip enable) "rCLK" from the microcomputer 3.
C1ock) and rDATA.

The audio output section 4 includes power amplifiers 5A and 5B.

5C, 5D, and n connected to each power amplifier.
'1 includes a left speaker 6A, a front right speaker 6B, a rear left speaker 6C, and a rear right speaker 6D. These speakers 6A, 6B, 6C.

The 6D has an electronic volume of 2 and a power amplifier of 5A.

The audio signals sent via 5B, 5C, and 5D are converted into audio and output.

Furthermore, in this embodiment, a motor voltage detection circuit 7 is connected to the microcomputer 3 as an air volume detection means for detecting the air volume of an air conditioning blower fan (not shown). That is, this motor voltage detection circuit 7 is interposed between a blower fan motor 8 for driving the blower fan and a motor drive circuit 9, and the motor drive circuit 9 controls the blower fan motor 8 according to a command from the air volume switching circuit 10. By detecting the motor voltage when the blower fan is rotated, the amount of air blown by the blower fan is indirectly detected. In this embodiment, the motor voltage detection circuit 7 detects the voltage of the blower fan motor 8 and sends a corresponding voltage detection signal Sv to the microcomputer 3.

Further, an inside/outside air switching detection switch 11 is connected to the microcomputer 3 as an inside/outside air switching detection means for detecting switching between inside and outside air. This inside/outside air changeover detection switch 11 is
It detects whether the intake door that switches between the inside air introduction side and the outside air introduction side of the air conditioner (not shown) is set to the inside air circulation position or the outside air introduction position, and outputs a detection signal to the microcomputer 3. There is. The reason why the inside/outside air switching detection switch 11 is provided is that the noise level inside the vehicle is different between the inside air circulation state and the outside air introduction state (it is more noisy in the inside air circulation state).

Next, a control program for the microcomputer 3 related to volume adjustment, which is a feature of this embodiment, will be explained with reference to the flowchart shown in FIG.

It is assumed that a cassette tape is loaded into the cassette deck 1 and music is being played at an appropriate volume from the speakers 6A to 6D. This starting volume (actually,
This is the level of the audio signal corresponding to this volume. )
is stored in the internal memory of the microcomputer 3, and the following control operations are performed using this as a reference volume.

Simultaneously with the start of control, the CPU (not shown) of the microcomputer 3 first detects whether or not the voltage detection signal Sv is input from the motor voltage detection circuit 7, thereby determining whether the blower fan is "ON" or not. (Step 3)
101). Then, the blower fan says “OFF
In this case, there is no need to adjust the volume on the CPU.
A command is given to the electronic volume to set the "correction level to 0", that is, to leave the volume at the standard volume (S107), and the control operation is ended. On the other hand, if the blower fan is rON, the CPU determines whether or not the inside air circulation state is present based on the output from the inside/outside air changeover detection switch 11 (S102).
. If the inside air is not being circulated, that is, if the outside air is being introduced, it is determined whether the motor voltage is 8 volts (■) or less based on the voltage detection signal Sv (3105). here,
When the motor voltage is 8V or less, the CPU commands the electronic volume 2 to set the correction level "1".

That is, a command is issued to set the volume to a level that is a decibel (dB) higher than the reference volume (S108). As a result, the volume of the sound output from the speakers 6A to 6D gradually becomes a level a (dB) higher than the reference volume.

On the other hand, if the motor voltage exceeds 8■ in step 5105, the CPU determines that the motor voltage is 8 to IOV.
It is determined whether the value is within the range (S106). When the motor voltage is in the range of 8 to 1°V, the CPU sets the electronic volume 2 to "correction level 2".
The command of, ie.

A command is issued to set the volume to a level that is b [dB] (here, b>a) higher than the reference volume (S109). As a result, the volume of the sound output from the speakers 6A to 6D gradually increases to a level b (dB) higher than the reference volume.Meanwhile, in step 5106, the motor current is
If it exceeds V, the CPU uses electronic volume 2.
"Correction level [3]" command, that is, c from the standard volume.
(dB) (where c>b) A command is issued to increase the volume to the added level (Silo). As a result, the volume of the sound output from the speakers 68 to 6D gradually becomes lower than the reference volume c ( dB) The volume will be at an increased level.

On the other hand, if it is determined in step 5102 that the internal air is being circulated, the CPU determines whether the motor voltage is 8V or less (3103). Here, the motor voltage is 8V
In the following cases, the CPU instructs the electronic volume 2 to "correction level 4", that is, d[dB] from the reference volume.
(Here, d>C) A command is issued to set the volume to the added level (Sill). As a result, speakers 6A to 6
The volume of the sound output from D gradually decreases from the standard volume.
The volume will be increased by [dB]. On the other hand, if the motor voltage exceeds 8■ in step 5103,
It is determined whether the motor voltage is within the range of 8 to IOV (S104). When the motor voltage is in the range of 8 to IOV, the CPU uses the electronic volume 2.
command of r correction level "5" J, that is, e from the reference volume.
(dB) (here, e > d) A command is issued to set the volume to the added level (3112). As a result, the volume of the sound output from the speakers 6A to 6D gradually becomes e (dB) higher than the reference volume.

On the other hand, in step 5104 above, the motor current is set to IOV.
If it exceeds the standard volume, the CPU issues a command to the electronic volume 2 to set the correction level "6" J.
(dB) (here, fee) gives a command to set the volume to the added level (S113). As a result, the volume of the sound output from the speakers 6A to 6D gradually becomes higher than the reference volume by f [dB].

In any of the above cases, after the volume correction command, the CPU returns to step 5101 and turns off the blower fan.
, repeat the above operations until . In this way, when the blower fan is turned off, step 51
The determination at step 01 is "no", and the CPIJ issues an r correction command to the electronic volume 2 (S107) and ends the control operation. As a result, the volume of the sound output from the speaker gradually shifts to the reference level.

According to the embodiment described above, the volume of the sound played from the speaker during tape playback can be corrected in six stages according to the air flow rate of the blower fan and switching between inside and outside air when the air conditioner is used or the heater is used, that is, outside air is introduced. state a-c (dB) 3
stage, 3 stages of d-f (dB) in internal air circulation state, total 6
stages (where a < b < c < d < e
Since the volume is corrected (< f), the conventional problem of the rotation noise of the blower fan motor and wind noise when the blower fan is in use increases the noise inside the vehicle, making it difficult to listen to music etc. This can be prevented, and since this volume correction is automatically performed by the microcomputer 3,
It is convenient and requires no effort to operate. Further, since the volume correction by the microcomputer 3 is performed based on the volume at the start, even if the air flow rate and the condition of the inside and outside air change during the process, the volume is corrected to an appropriate volume.

In the above embodiment, the cassette deck 1 is used as an audio source, but the present invention is not limited to this, and other audio sources such as FM, AM radio, or CD player may also be used. Of course, you may use it.

Furthermore, in the above embodiment, a motor voltage detection circuit that indirectly detects the amount of air blown by a blower fan is used as the air amount detection means, but instead of this, the motor current or the rotation speed of the motor may be detected. It is also possible to use a suitable flow sensor that directly detects the air flow.

〔Effect of the invention〕

Since the present invention is configured and functions as described above, according to this, the electronic volume is controlled by the volume adjustment function of the control unit according to the air flow rate of the blower fan and the switching state of the inside and outside air. The volume of the sound source such as a cassette deck or CD player is corrected in response to changes in the noise level in the vehicle interior due to the rotating sound of the blower fan motor and wind noise when the heater is in use or when the heater is in use. This prevents the inconvenience of having difficulty listening to music while using the blower fan. Furthermore, since this volume correction is automatically performed by the control section, it is convenient and requires no effort to operate. Therefore, it is an unprecedented and excellent vehicle-mounted device that allows passengers to always listen to music at an appropriate volume without being affected by the indoor air conditioning status of the vehicle, and without the need for any volume correction operations by the passenger. A sound device can be provided.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a flowchart showing the main control program of the microcomputer shown in FIG. 1...Cassette deck as a sound source, 2
...Electronic volume, 3..Microcomputer as control section, 4..Audio output section, 7.Old.
・Motor voltage detection circuit as air volume detection means, 11...
... An inside/outside air switching detection switch as an inside/outside air switching detection means.

Claims (1)

[Claims] (1) A sound source, an electronic volume that inputs an audio signal output from this sound source, increases or decreases the level of the audio signal according to an external command, and outputs it to an audio output section, and controls this electronic volume. and a control section, the control section is connected to an air volume detection means for detecting the air flow volume of an air conditioning blower fan of the vehicle, and an inside/outside air switching detection means for detecting switching between inside and outside air, and An in-vehicle audio device characterized in that the control section has a volume adjustment function that controls the electronic volume according to output signals from both the detection means.