Audio System

Abstract

To provide a voice system for allowing conversation voice of a crewman to be easily heard.SOLUTION: A voice system includes: a plurality of exciters EC1-EC4 attached to a ceiling 40 corresponding to positions of respective seats Q1-Q4 inside a vehicle, so as to output voice by vibrating the ceiling 40 based on a drive signal to be applied; a plurality of microphones MC1-MC4 attached close to headrests of the respective seats; and a controller 10 for outputting a drive signal to drive the plurality of exciters EC1-EC4 in response to an audio reproduction signal, and outputting a drive signal to drive the exciters or other speakers in response to a voice signal that has been input from one of the plurality of microphones MC1-MC4.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an audio system having a function of assisting conversation between passengers, and more particularly to an interior-mounted speaker system using an exciter mounted in the interior. [Background technology]

[0002] The way passengers spend their time in a vehicle is becoming more diverse, and the demand for individual sound source playback devices for each seat (zone sound) and in-car communication (ICC) is increasing. The in-car conversation support device enables passengers to clearly hear the conversation between each other even in noisy environments or when music or the like is being played (for example, Patent Documents 1, 2, and 3). As shown in FIG. 1, the in-car conversation support device of Patent Document 1 is provided with speakers 101, 102, 103, and 104 at each seat, and microphones 105, 106, 107, and 108 for each seat. A control unit 200 enables the passengers' conversation voices collected by the microphones to be output from the speakers 101 to 104, and enables the audio playback sound played by an audio device 203 to be output from the speakers 101 to 104. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-51392 A [Patent Document 2] JP 2010-163054 A [Patent Document 3] Japanese Patent Application Publication No. 11-342799 Summary of the Invention [Problem to be solved by the invention]

[0004] FIG. 2 is a diagram showing a schematic configuration example of a conventional seat conversation assistance device. Speakers SP1 and SP2 are attached near the front seats in the vehicle, speakers SP3 and SP4 are attached near the rear seats, and speakers SP5 and SP6 are attached at the rear. Microphones MC1, MC2, MC3, and MC4 for inputting the conversation voices of the passengers at each seat are attached according to the position of each seat. A controller 10 inputs an audio signal S1 collected by the microphones MC1 to MC4, and outputs the conversation voice from the speakers SP1 to SP6 based on the input audio signal S1. The controller 10 determines the seat of the passenger who has spoken based on the level of the audio signal input to the microphones MC1 to MC4, for example, and outputs the conversation voice from the speakers of the seats of the other passengers. Alternatively, the seat of the passenger who has spoken may be determined by using a talk switch or a seat sensor provided at each seat in combination, or the conversation voice may not be output from a seat where no passenger is seated. Furthermore, the controller 10 receives an audio playback signal S2 reproduced by the audio device 20, and outputs the audio playback sound from the speakers SP1 to SP6.

[0005] The input and output of conversational voice uses telephone reproduction technology, which has several performance indicators, such as the voice from the front seat being audible in the rear seat, low noise in the sound output from the rear seat, low signal processing delay and natural sounding, sufficient echo cancellation, no feedback, good sound quality, and no sound interruptions.

[0006] In order to satisfy these performance indexes, if the audio playback sound output from the speaker near the driver's seat or road noise is captured by the microphone that captures the conversation voice of the occupants, the S / N (signal-to-noise ratio) of the audio signal output from the speaker of the far-end seat will be low, making the conversation voice difficult to hear. In addition, since the conversation voice is output from the speaker with a delay, there is a problem that there is a lot of reverberation and the entire interior of the vehicle feels saturated. This situation will be explained using FIG. 3. When the driver U1 speaks, the conversation voice P1 is input from the microphone MC1 attached near the steering wheel, and the input audio signal S1 is signal-processed by the controller 10, and the conversation voice of the driver U1 is output from the speaker SP5 on the rear seat side. On the other hand, if the audio playback sound P2 is output from the speaker SP1 installed on the door near the driver U1's seat, when the microphone MC1 collects the audio playback sound P2, the audio playback sound is mixed into the conversation voice output from the speaker SP5 on the rear seat side. This makes it difficult for the passenger U2 in the back seat to hear the conversation of the driver U1.

[0007] To address this issue, it is possible to use an adaptive filter to remove the reproduced audio from the conversational voice, or to use a directional microphone; however, in order to further improve the performance of the conversational voice, it is desirable to improve the input part of the conversational voice so that the reproduced audio is not mixed into the conversational voice.

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an audio system that solves the above-mentioned problems and makes it easier to hear the conversations of passengers. [Means for solving the problem]

[0009] The audio system of the present invention comprises a plurality of exciters attached to the ceiling corresponding to each seat position in the vehicle and which output sound by vibrating the ceiling based on an applied drive signal, a plurality of microphones attached near the headrests of each seat, and control means which outputs a drive signal for driving the exciters in response to an audio playback signal, and which outputs a drive signal for driving the exciters or other speakers in response to an audio signal input from any of the plurality of microphones.

[0010] In one embodiment, the exciter is attached to the reverse side of an interior ceiling base material. In one embodiment, the exciter is attached above the head of an occupant when seated in the seat. In one embodiment, the microphone is attached at a position blocked by the head of the occupant when seated in the seat. In one embodiment, the microphone is attached between the backrest and headrest of the seat. In one embodiment, the other speaker is attached near the headrest of the seat. In one embodiment, the control means has a conversation assistance function for transmitting the conversation voice of the occupant to other occupants. Effect of the Invention

[0011] According to the present invention, since a plurality of exciters are attached to the ceiling and a plurality of microphones are attached near the headrests of the seats, the sound output by the exciters is prevented from being directly input to the microphones due to the barrier between the heads of the passengers and the headrests. As a result, the conversation sound is separated from other sound sources such as audio playback sounds and input to the microphones, reducing noise contained in the conversation sound and making it easier to hear the conversation sound. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a conventional inter-seat conversation assistance device; [Diagram 2] FIG. 1 is a diagram showing an example of the configuration of a conventional inter-seat conversation assistance device; [Diagram 3] 1A and 1B are diagrams illustrating problems with a conventional inter-seat conversation assistance device. [Figure 4] 1 is a diagram showing a schematic configuration of an audio system having a seat conversation assistance function according to an embodiment of the present invention; [Diagram 5] FIG. 2 is a cross-sectional view showing an example of installation of an exciter according to an embodiment of the present invention. [Figure 6] FIG. 2 is a perspective view showing an example of how a microphone according to an embodiment of the present invention is attached; [Figure 7] 1A and 1B are diagrams illustrating the effects of an audio system according to an embodiment of the present invention. [Figure 8] FIG. 13 is a diagram showing a schematic configuration of an audio system according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The audio system according to the present invention has a function of outputting conversation between passengers in addition to outputting audio playback sound inside a moving body such as an automobile. Also, due to the spread of electric vehicles, vehicle weight reduction (changes in vehicle shape, use of resin doors), changes in vehicle structure that prioritize space for the driver and passengers, and changes in signal processing technology, there is a demand for the development of ultra-lightweight speakers that can be installed in positions other than existing positions. Therefore, the audio system according to the present invention uses an interior-mounted speaker with an exciter built into the interior of the vehicle. EXAMPLES

[0014] Next, an embodiment of the present invention will be described with reference to the drawings. Note that the scale of the drawings is exaggerated in order to facilitate understanding of the invention, and does not necessarily represent the scale of an actual product.

[0015] Fig. 4(A) is a plan view showing the mounting positions of an exciter and a microphone of an audio system according to an embodiment of the present invention, and Fig. 4(B) is a cross-sectional view showing the mounting positions of an exciter and a microphone of the audio system in a three-dimensional manner. Here, an example is shown in which two front seats Q1 and Q2 are arranged at the front of the vehicle interior, and two rear seats Q3 and Q4 are arranged at the rear, but this is just one example, and other numbers of seats and arrangements of seats (e.g., three rows of seats) may be used.

[0016] The audio system 1 includes a plurality of exciters EC1, EC2, EC3, EC4 attached to the ceiling 40 corresponding to the positions of each of the seats Q1, Q2, Q3, Q4, a plurality of microphones MC1, MC2, MC3, MC4 attached near the headrests of each of the seats Q1, Q2, Q3, Q4, a controller 10 electrically connected to the exciters EC1 to EC4 and the microphones MC1 to MC4 and controls the output of audio, and an audio device 20 that provides an audio playback signal S2 to the controller 10.

[0017] The seat Q1 includes a seating portion 30, a backrest portion 32, and a headrest 34, and the microphone MC1 is attached near the headrest 34. For example, as shown in Fig. 6, the microphone MC1 may be attached in the space between the headrest 34 and the backrest portion 32, or may be embedded in the headrest 34 or the backrest portion 32. Similarly, microphones MC2, MC3, and MC4 are attached near the headrest 34 in the other seats Q2, Q3, and Q4. The microphones MC1 to MC4 input the conversation voices of the occupants, and the audio signals S1 of the conversation voices collected by the microphones MC1 to MC4 are input to the controller 10 via a wired or wireless connection.

[0018] An exciter EC1 is attached to a position on the ceiling 40 corresponding to the seat Q1. As shown in FIG. 4B, the exciter EC1 is attached near the head of the occupant U1 when the occupant U1 sits in the seat Q1. A preferable positional relationship between the exciter EC1 and the microphone MC1 is such that the sound output from the exciter EC1 is blocked by the head or headrest 34 of the occupant U1, and the sound output from the exciter EC1 is not directly input to the microphone MC1. Similarly, the other exciters EC2, EC3, and EC4 are attached to positions on the ceiling 40 corresponding to the seats Q2, Q3, and Q4, and are attached at positions such that the sound output from the exciters EC2, EC3, and EC4 is blocked by the head or headrest of the occupant, and is not directly input to the microphones MC2, MC3, and MC4.

[0019] The exciters EC1 to EC4 are driven by an audio drive signal DV outputted by wire or wirelessly from the controller 10. The exciters EC1 to EC4 are vibrators that convert the audio drive signal DV into vibrations, like normal cone-type speakers, but can be made smaller, more space-saving, and lighter than cone-type speakers.

[0020] 5 is a cross-sectional view showing a schematic view of the installation of the exciter EC1. The interior material of the ceiling (ceiling base material) 42 includes a front surface 44 and a back surface 46, and the exciter EC1 is installed on the back surface side of the interior material 42. For this reason, the occupant U1 cannot see the exciter EC1 from the front surface 44. The interior material 42 also functions as a diaphragm, and when the exciter EC1 is vibrated by the audio drive signal DV, the vibration is transmitted to the interior material 42, and sound is output from the ceiling 40 due to the vibration of the interior material 42. The other exciters EC2 to EC4 are similarly configured.

[0021] The audio device 20 is a device having a function of reproducing an audio signal, and its configuration is not particularly limited. The audio device 20 can be, for example, an AVN (audio-visual-navigation) device, a smartphone, a portable audio player, etc. When the audio device 20 receives an instruction from a passenger, it starts reproducing an audio signal, and an audio reproduction signal S2 is output to the controller 10.

[0022] The controller 10 has at least a function of causing the exciters EC1-EC4 to output audio sounds reproduced by the audio device 20, and a function of causing the exciters EC1-EC4 to output conversational voices of the occupants. The controller 10 can include hardware resources such as a DSP, a microcontroller, an amplifier, and an adaptive filter required to execute such functions, and software resources for controlling the hardware. The controller 10 also cooperates with the audio device 20, and can control the audio device 20 or be controlled by the audio device 20.

[0023] When the controller 10 receives the audio playback signal S2 from the audio device 20, it outputs an audio drive signal DV corresponding to the audio playback signal S2 to the exciters EC1 to EC4, causing the exciters EC1 to EC4 to output audio sound from the ceiling 40 via the exciters EC1 to EC4.

[0024] Also, when the conversation voice of the occupant is input as the audio signal S1 from the microphones MIC1 to MC4, the controller 10 performs necessary signal processing on the audio signal S1, drives one or more exciters via the audio drive signal DV, and outputs the conversation voice from the ceiling 40. In one embodiment, the controller 10 identifies the seat from which the speech is made based on the level of the audio signal input to the microphones MIC1 to MC4, and outputs the audio drive signal to the exciter corresponding to the other seats. For example, when the occupant U1 in the driver's seat Q1 shown in FIG. 4(B) speaks, the level of the input audio signal to the microphone MC1 becomes large, so the controller 10 identifies the driver's seat Q1 from which the speech is made, outputs the audio drive signal DV to the exciters EC2 to EC4 corresponding to the other seats Q2 to Q4, and outputs the conversation voice of the occupant U1 from the ceiling. In yet another embodiment, when a weight sensor that detects the presence or absence of an occupant in a seat is mounted, the controller 10 can also prevent the audio drive signal DV from being output to the exciter corresponding to the seat where no occupant is present, based on the detection result of the weight sensor.

[0025] Next, the effect of the audio system of this embodiment will be described. In a conventional audio system, as shown in Fig. 3, a microphone MC1 attached near the steering wheel inputs the conversation voice P1 of the occupant U1 and the audio voice P2 output from the door speaker SP1, so that the conversation voice P1 cannot be input separately from the audio voice P2. Furthermore, the microphone MC1 is prone to picking up road noise and the like. This causes the noise of the conversation voice output from the speaker to increase, making it difficult to hear the conversation voice.

[0026] In contrast, in the audio system of this embodiment, as shown in FIG. 7, when the occupant U1 speaks while the audio sound reproduced by the audio device 20 is being output by the exciter EC1, the audio sound P2 output by the exciter EC1 is blocked by the head of the occupant U1, and is prevented from being directly input to the microphone MC1. Furthermore, road noise is also less likely to be picked up. In addition, since the microphone MC1 is attached near the headrest 34, the microphone MC1 can input the speech sound propagating through the bones and skin of the head of the occupant U1, and even if the input level of the speech sound of the occupant U1 propagating through the air decreases, this decrease is offset. This makes it possible to reduce the noise of the conversation sound output from the exciter, making the conversation sound easier to hear.

[0027] Next, another embodiment of the present invention will be described. In the above embodiment, an example was shown in which the conversation voices of the occupants were output from an exciter, but the conversation voices of the occupants can also be output from a speaker other than the ceiling exciter. Fig. 8 shows an audio system 1A according to another embodiment. Here, an example is shown in which speakers SP7 and SP8 are installed for rear seats Q3 and Q4. The speakers SP7 and SP8 are installed near or inside the headrests of seats Q3 and Q4 so that the conversation voices can be easily heard by the occupants in seats Q3 and Q4.

[0028] When the controller 10 outputs audio sound from the audio device 20, it drives the exciters EC1 to EC4 via the audio drive signal DV1, and when the controller 10 outputs conversation sound from the rear seats Q3 and Q4, it drives the speakers SP7 and SP8 via the audio drive signal DV2. When the controller 10 outputs conversation sound from the front seats Q1 and Q2, it drives the exciters EC1 and EC2 via the audio drive signal DV1. In this way, by outputting conversation sound from a speaker different from the ceiling exciter, it is possible to hear the conversation sound more clearly. In the example of FIG. 8, the speakers SP7 and SP8 are attached near the headrests of the rear seats Q3 and Q4, but speakers may also be attached near the headrests of the front seats Q1 and Q2. In this case, all conversation sound is output from the speakers, not the exciters.

[0029] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the gist of the invention described in the claims. [Explanation of symbols]

[0030] SP1~SP6: Speakers MC1~MC4: Microphones EC1~EC4: Exciter 10: Controller 20: Audio equipment 30: Seating area 32: Backrest 34: Headrest 40: Ceiling 42: Interior panel

Claims

1. a plurality of exciters attached to a ceiling corresponding to each seat position in the vehicle and vibrating the ceiling based on an applied drive signal to output a sound; Multiple microphones attached near the headrests of each seat; a control means for outputting a drive signal for driving the exciter in response to an audio playback signal, and for outputting a drive signal for driving the exciter or another speaker in response to an audio signal input from any one of the plurality of microphones; The exciter is mounted above the head of an occupant when seated in the seat, The microphone is mounted in a position that is blocked by the head of an occupant when seated in the seat.

2. 10. The audio system of claim 1, wherein the exciter is mounted to the underside of an interior ceiling substrate.

3. 10. The audio system of claim 1, wherein the microphone is mounted between a seat back and a headrest.

4. 2. The audio system of claim 1, wherein the other speaker is mounted adjacent a headrest of the seat.

5. The audio system further includes a detection means for detecting the presence or absence of an occupant in each seat; The control means has a conversation assistance function for transmitting the conversation voice of the occupant to other occupants, 2. The audio system according to claim 1, wherein the control means identifies the seat from which speech is being spoken based on the level of the audio signal input from the microphone, outputs drive signals to exciters corresponding to other seats based on the identification result, and does not output drive signals to exciters corresponding to seats with no occupant based on the detection means.

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