JPH04110100U - In-vehicle sound reproduction device - Google Patents

Abstract

(57) [Summary] [Purpose] Automatically optimize the sound field environment for each occupant according to the number of occupants. [Structure] The front passenger seat occupant detection unit 1 detects the presence or absence of a passenger in the front passenger seat, and the reproduction sound field characteristic switching unit 2 detects the presence or absence of a passenger in the front passenger seat. When there is a passenger in the passenger seat, the reproduction sound field characteristics are changed to suit both the driver's seat and the front passenger's seat.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to an in-vehicle sound reproduction device, and in particular, the left channel and right channel audio reproduction device. audio signals to the front and rear left channel speakers and right channel speaker. The present invention relates to an in-vehicle sound reproduction device which is reproduced by a car.

0002

[Conventional technology]

In recent years, in the field of car audio, digital devices such as in-vehicle CD players and in-vehicle DATs have been increasing. With the spread of digital audio sources, there is a growing trend toward higher quality sound. like this In a car audio system, the left and right channels are placed in the front and rear of the vehicle, respectively. The left channel speakers are placed symmetrically, and the left channel played from the audio source is front and rear left channel audio signals. driver and each right channel speaker to transform the vehicle interior into a single acoustic space. I'm trying to play back Leo sound.

0003

[Problem that the idea aims to solve]

By the way, simply convert the left channel and right channel audio signals into filters, respectively. When inputting to the front or rear left channel and right channel speakers, each speaker The distance between the speakers and the driver's seat is different, and the sound from each speaker may have different distances before reaching the driver's seat. Since the time required is different, the sound image will be biased and the phase at the driver's seat will not match. , the sound field environment deteriorates.

0004 Therefore, in the past, the audio system was designed to cancel out the difference in distance between the driver's seat and each speaker. Delay the signal to eliminate bias in the sound image and adjust the sound field so that the phase at the driver's seat matches. It is being corrected. However, although this method improves the sound field environment in the driver's seat, In the passenger seat, the time difference between the sounds emitted from each speaker becomes larger, and the phase shifts as well. As a result, the sound field environment deteriorates further.

[0005] From the above, the purpose of this invention is to automatically adjust the sound field environment for each occupant according to the number of occupants. The purpose of the present invention is to provide an in-vehicle sound reproduction device that can be optimized.

[0006]

[Means to solve the problem]

In this invention, front and rear left channel speakers and right channel An in-vehicle sound reproduction device that reproduces sound through a speaker detects the presence or absence of a passenger in the front passenger seat. depending on the occupant detection means to be detected and the presence or absence of an occupant in the front passenger seat detected by the occupant detection means. , when there is no passenger in the passenger seat, the playback sound field characteristics are switched to match the driver's seat. When there is a passenger in the seat, the playback sound field characteristics are switched to suit both the driver and passenger seats. This is achieved by providing reproduction sound field characteristic switching means.

[0007]

[Effect]

According to the present invention, the presence or absence of a passenger in the front passenger seat is detected, and the , when there is no passenger in the passenger seat, the playback sound field characteristics are switched to match the driver's seat. When there is a passenger in the seat, the playback sound field characteristics are switched to suit both the driver and passenger seats. Ru. As a result, when there is no passenger in the passenger seat, the sound field will automatically adjust to suit the driver's seat. If there is a passenger in the passenger seat, the sound field environment will automatically be adjusted to suit the driver and passenger seats. This allows you to always create the optimal sound field environment according to the number of passengers, and also to improve the sound field. There is also no need to perform a characteristic switching operation.

[0008]

【Example】

FIG. 1 is an overall configuration diagram of an in-vehicle sound reproduction device according to an embodiment of the present invention.

[0009] 1 is a passenger detection unit for the passenger seat, which detects whether the passenger is wearing a seatbelt or not. Detect presence. Passenger seat occupant detection hand section 1 detects when there is no occupant in the passenger seat and the seatbelt is not occupied. When the seat belt is not installed, the passenger detection signal output is set to L level, and the When there is an occupant in the vehicle and the seat belt is fastened, the occupant detection signal output is set to H level. shall be.

Reference numeral 2 denotes a reproduction sound field characteristic switching unit, which switches the reproduction sound field characteristics to suit the driver's seat when there is no occupant in the passenger seat, depending on whether or not there is an occupant in the front passenger seat. When the driver is present, the playback sound field characteristics are switched to suit both the driver and passenger seats. 2a is a first delay circuit that delays the L channel audio signal input to the input terminal L _IN with a variable delay time, and 2b is a second delay circuit that delays the R channel audio signal input to the input terminal R _IN with a variable delay time. 2c is a third delay circuit that delays the L-channel audio signal input to the input terminal L _IN with a variable delay time, and 2d is a third delay circuit that delays the R-channel audio signal input to the input terminal R _IN with a variable delay time. 4 delay circuits, 2e is a first phase variable circuit that changes the phase of the L channel audio signal output from the first delay circuit by 0° or 180°, and 2f changes the phase of the R channel audio signal output from the second delay circuit. 2g is a third phase variable circuit that changes the phase of the L channel audio signal output from the third delay circuit by 0° or 180°; A fourth phase variable circuit 2i that changes the phase of the R channel audio signal by 0° or 180° is a microcomputer-configured controller, and according to the detection output of the front passenger seat occupant detection unit 1, the first delay circuit 2a to the fourth delay circuit 2d, and performs phase variable control on the first to fourth variable phase circuits 2e to 2h.

[0011] 3 is an amplifier for the front L channel, which is output from the first phase variable circuit 2e. amplify the L channel audio signal. 4 is for front R channel It is an amplifier and receives the R channel audio signal output from the second phase variable circuit 2f. amplify the number. 5 is an amplifier for the rear L channel, and the third phase variable circuit 2g Amplify the L channel audio signal output from the . 6 is rear R channel This is an amplifier for the R channel audio output from the fourth variable phase circuit 2h. amplify the signal.

0012 7 is a speaker for the front L channel, and the L channel is amplified by amplifier 3. It is driven by a channel audio signal to reproduce sound. 8 is front R channel This is a speaker for audio channels, and uses the R channel audio signal amplified by amplifier 4. is driven to reproduce sound. 9 is the rear L channel speaker, and the amplifier It is driven by the L-channel audio signal amplified in step 5 to reproduce sound. 1 0 is the speaker for the rear R channel, and the R channel is amplified by amplifier 6. It is driven by an audio signal to reproduce sound.

[0013] Figure 2 is a flowchart showing the operation of the controller 2i, and Figure 3 is the speaker arrangement inside the vehicle. 4 and 5 are explanatory diagrams illustrating the operation of the reproduction sound field characteristic switching section 2. , and will be explained below with reference to these figures.

In FIG. 3, t _a is the time required for the sound emitted from the front L channel speaker 7 to reach the center of the driver's seat, and similarly, t _b , t _c , and t _d are the time required for the sound emitted from the front L channel speaker 7 to reach the center of the driver's seat. This is the time required for the sounds emitted from the R channel speaker 8, the rear L channel speaker 9, and the rear R channel speaker 10 to reach the center of the driver's seat.

[0015] When there is no occupant in the front passenger seat, the front passenger seat occupant detection unit 1 outputs an L level occupant detection signal since the seat belt is not fastened. When the occupant detection signal is at the L level, the controller 2i determines that there is no occupant in the passenger seat (NO in step 101), and first delays the first delay circuit 2a in order to obtain reproduced sound field characteristics suitable for the driver's seat. Variable delay time control is performed to set the time τ ₁ = t _c - t _a , and similarly, τ ₂ = t _c - t _b for the second delay circuit 2 b and τ ₄ = t _c for the fourth delay circuit 2 d. _-td , and for the third delay circuit 2c, variable delay time control is performed to set _τ3 = 0 (step 102).

Next, the controller 2i performs phase variable control on the first to fourth variable phase circuits 2e to 2h to set all phase variable amounts θ ₁ to _{θ 4} to 0° (through) (step 103 ).

[0017] Therefore, the amplifier 3 receives the L-channel audio signal, which is delayed by τ ₁ = t _c - t _a without changing the phase, by passing through the first delay circuit 2 a and the first phase variable circuit 2 e. is input. Furthermore, an R channel audio signal whose phase remains unchanged and is delayed by τ ₂ =t _c −t _b is input to the amplifier 4 by passing through the second delay circuit 2 b and the second phase variable circuit 2 f. . The amplifier 5 receives an L channel audio signal whose phase does not change and is not delayed by passing through the third delay circuit 2c and the third phase variable circuit 2g. Further, the amplifier 6 receives an R channel audio signal which is delayed by τ ₄ =t _c −t _d without changing its phase by passing through the fourth delay circuit 2 d and the fourth variable phase circuit 2 h. . Each of the amplifiers 3 to 6 amplifies the input audio signal and outputs it to the speakers 7 to 10 (see FIG. 4).

[0018] As a result, the time required for the sound emitted from each speaker 7 to 10 to reach the driver's seat is the same. Similarly, in the driver's seat, the sound image is not biased and the phase is also the same, making it easier for the driver. automatically creates the optimal sound field environment.

Unlike this, when an occupant gets on the front passenger seat and fastens the seat belt, the front passenger seat occupant detection section 1 outputs an H-level occupant detection signal. When the occupant detection signal is at H level, the controller 2i determines that there is an occupant in the front passenger seat (YES in step 101), and in order to obtain reproduction sound field characteristics suitable for the driver's seat and front passenger seat, first the first delay circuit 2a is activated. Similarly, τ ₂ = 2 ms for the second delay circuit 2b, τ ₃ = 0 for the third delay circuit 2c, and τ ₃ =0 for the fourth delay circuit 2d. Then, variable delay time control is performed to set τ ₄ =0 (step 104).

Next, the controller 2i performs phase variable control on the first phase variable circuit 2e and the third phase variable circuit 2g to set the phase variable amounts θ ₁ and θ ₃ to 180° (inversion), and Phase variable control is performed on the variable circuit 2f and the fourth variable phase circuit 2h to set the phase variable amounts θ ₂ and θ ₄ to 0° (through) (step 105).

[0021] Therefore, the amplifier 3 is connected to the first delay circuit 2a and the first phase variable circuit 2e. As a result, the phase of the L-channel audio signal is inverted and the L-channel audio signal is delayed by 2ms. is input. The amplifier 4 also includes a second delay circuit 2b and a second variable phase circuit 2f. The R channel audio signal is delayed by 2ms with the phase unchanged. The audio signal is input. The amplifier 5 includes a third delay circuit 2c and a third phase variable circuit 2. The L-channel audio signal is phase-inverted and not delayed by passing through The number is entered. Furthermore, the amplifier 6 includes a fourth delay circuit 2d and a fourth variable phase circuit 2. h, the R channel audio remains in phase and is not delayed. signal is input. Each amplifier 3 to 6 amplifies the input audio signal. and outputs to the speakers 7 to 10 (see FIG. 5).

[0022] As a result, the sound output from the rear speakers 9 and 10 and the sound output from the front speakers 7 and 8 is corrected by a certain amount of time difference, and the R channel side speaker Since the phases of speakers 7 and 9 on the L channel side are inverted with respect to speakers 8 and 10, The sound image can be slightly expanded for both the driver and passenger seats. This can slightly improve the sound field environment for both the driver and front passenger.

Note that when it is detected that there is an occupant in the passenger seat, the controller 2i performs variable delay time control to set the delay time τ ₁ =τ ₂ =2 ms for the first delay circuit 2a and the second delay circuit 2b. Then, the third delay circuit 3c and the fourth delay circuit 2d are subjected to variable delay time control such that τ ₃ =τ ₄ =0, and the first phase variable circuit 2e and the fourth phase variable circuit 2h are controlled to have a phase change. Phase variable control is performed in which the variable amounts θ ₁ and θ ₄ are set to 0° (through), and the phase variable amounts θ ₂ and θ 3 are set to 180° (inverted) for the second phase variable circuit 2f and the _third phase variable circuit 2g. ), it is possible to improve the sound field environment for the driver and passenger in the passenger seat, as in the case of FIG. 5 (see FIG. 6).

Further, when it is detected that there is an occupant in the front passenger seat, the controller 2i performs variable delay time control to set the delay times τ ₁ to _{τ 4} =0 for the first delay circuit 2a to the fourth delay circuit 2d. Then, phase variable control may be performed to set the phase variable amounts θ ₁ to θ ₄ to 0° (through) for the first to fourth variable phase circuits 2e to 2h. In this case, it is not possible to improve the sound field environment of the driver's seat and the passenger seat as much as in the case of FIGS. As a result, a relatively good sound field environment can be maintained for both the driver and the passenger in the passenger seat.

[0025] In addition, in the above embodiment, L channel speakers and R channel speakers are installed at both the front and rear. Although the case where channel speakers are arranged has been explained, the present invention is not limited to this in any way. If you place the L channel speaker and R channel speaker only in the front without It can be similarly applied to cases where

[0026]

[Effect of the idea]

As described above, according to the present invention, there is provided an occupant detection means for detecting the presence or absence of an occupant in the front passenger seat; Depending on whether there is a passenger in the passenger seat detected by the output means, if there is no passenger in the passenger seat, Switch to playback sound field characteristics that match the driver's seat, and when there is a passenger in the passenger seat, the sound field characteristics will change to suit the driver's seat. A means for switching the reproduction sound field characteristics to match the reproduction sound field characteristics for both passenger seats. The system detects the presence or absence of an occupant in the front passenger seat, and automatically detects whether or not there is an occupant in the front passenger seat. When no passenger is present, the playback sound field characteristics are switched to suit the driver's seat, and when there is a passenger in the passenger seat. The system is configured to switch to playback sound field characteristics that match both the driver's and passenger's seats when Therefore, when there is no passenger in the passenger seat, the sound field environment is automatically adjusted to suit the driver's seat. When there is a passenger in the passenger seat, the sound field environment will automatically be adjusted to suit the driver and passenger seats. This makes it possible to always create an optimal sound field environment according to the number of passengers, and also to improve the sound field characteristics. No switching operation is required.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an in-vehicle sound reproduction device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the controller of FIG. 1;

FIG. 3 is an explanatory diagram showing the arrangement of the speakers in FIG. 1 in a vehicle interior.

FIG. 4 is an explanatory diagram illustrating the operation of the reproduction sound field characteristic switching section in FIG. 1;

FIG. 5 is an explanatory diagram illustrating the operation of the reproduction sound field characteristic switching section of FIG. 1;

FIG. 6 is an explanatory diagram illustrating the operation of a reproduction sound field characteristic switching section according to a modification of FIG. 1;

[Explanation of symbols]

1 Passenger seat occupant detection unit 2 Playback sound field characteristics switching section 3, 4, 5, 6 amplifier 7, 8, 9, 10 speakers

Claims (1)

[Scope of utility model registration request] Claim 1: An in-vehicle sound reproduction device that reproduces sound using front and rear left channel speakers and right channel speakers, comprising: an occupant detection means for detecting the presence or absence of an occupant in a front passenger seat; When there is no passenger in the front passenger seat, the playback sound field characteristics are switched to match the driver's seat, and when there is a passenger in the front passenger seat, the playback sound field characteristics are set to match both the driver and front passenger seats. An in-vehicle sound reproducing device characterized in that it is provided with reproduction sound field characteristic switching means for switching to a reproduction sound field characteristic.