Sound distribution device for motor vehicle seats providing a sound bubble effect

Abstract

The present invention relates to a sound distribution device (2) comprising: a support (6); and a plurality of loudspeakers (7) arranged on the support and oriented so as to converge toward a listening zone; characterized in that the plurality of loudspeakers are distributed in a first array (8) of loudspeakers and a second array (10) of loudspeakers, said first array and said second array being convergent. The invention also relates to a motor vehicle comprising a sound distribution device that is electrically connected to an audio system, characterized in that said sound distribution device is according to the invention and the audio system is configured to individually control, in particular by means of one or more filters, a plurality of the loudspeakers of each of the first network and of the second network.

Description

[0001] DESCRIPTION

[0002] TITLE: SOUND DIFFUSION DEVICE FOR MOTOR VEHICLE SEATS PROVIDING A SOUND BUBBLE EFFECT

[0003] Technical field

[0004] The present invention claims priority from French application 2209625 filed on September 22, 2022, the content of which (text, drawings and claims) is incorporated herein by reference. The present invention relates to the field of motor vehicles, more particularly the field of motor vehicle loudspeakers.

[0005] Prior art

[0006] Today's car manufacturers are increasingly focusing on personalized listening zones that provide specific sound spaces for each seat occupant. These sound spaces are commonly referred to as "sound bubbles" and allow for a personalized listening experience for each occupant.

[0007] In this regard, current motor vehicles are equipped with loudspeakers arranged as close as possible to the occupants' ears, for example, in the headrests, seat backs and / or the dashboard.

[0008] The published patent document FR 3 098 338 A1 discloses a seat headrest comprising a sound reproduction device capable of ensuring a specific sound space at the level of each headrest.

[0009] However, the solution disclosed by the document has room for improvement, since the disclosed sound reproduction device allows obtaining the sound bubble only for low frequencies up to 800 Hz. However, to effectively ensure a sensation of sound bubble, it is necessary to achieve an attenuation of the "parasitic" sound of 30 dB over the entire audible spectrum (20 Hz - 20 kHz).

[0010] Statement of the invention

[0011] The present invention aims to overcome at least one of the drawbacks of the aforementioned state of the art. More particularly, the invention aims to propose a simple, efficient and economical solution for efficiently creating personalized listening zones for frequencies above 800 Hz.

[0012] To this end, the invention relates to a sound diffusion device, comprising:

[0013] - a support; and

[0014] - several loudspeakers arranged on the support and oriented in a convergent manner towards a listening area; remarkable in that the several loudspeakers are distributed into a first network of loudspeakers and a second network of loudspeakers, said first network and said second network being convergent.

[0015] According to one embodiment, the support comprises a first face on which the first network of loudspeakers is arranged, and a second face on which the second network of loudspeakers is arranged, said first face and said second face being oriented in converging main directions.

[0016] Advantageously, each of the principal directions corresponds to a direction perpendicular to the first face or to the second face.

[0017] According to one embodiment, the first speaker array and the second speaker array each comprise at least three speakers.

[0018] Preferably, the first speaker network and the second speaker network comprise at least five, and more preferably at least six speakers.

[0019] According to one embodiment, each loudspeaker has an average diameter of less than 30 mm and is capable of reproducing sounds between 800 Hz and 20 kHz.

[0020] According to one embodiment, the loudspeakers of the first network are oriented towards a first sub-zone of the listening area and the loudspeakers of the second network are oriented towards a second sub-zone of the listening area, separate from the first listening sub-zone.

[0021] According to one embodiment, the first listening sub-zone is separated from the second listening sub-zone by a distance of between 15 and 30 cm, so as to correspond, respectively, to the two ears of a person. According to one embodiment, the loudspeakers of the first network have different and convergent orientations and / or the loudspeakers of the second network have different and convergent orientations.

[0022] According to one embodiment, each of the speakers of the first network and / or the second network comprises a rear enclosure forming a load volume.

[0023] According to one embodiment, the support is a headrest, in particular of a seat, and / or an upper part of a backrest of the seat, said support further comprising a low-frequency loudspeaker arranged adjacent to each of the first and second loudspeaker arrays. Preferably, the low-frequency loudspeaker is larger in size to address the lowest frequencies, having an average diameter of less than 60 mm and is capable of reproducing sounds between 80 Hz and 1 kHz.

[0024] The invention also relates to a motor vehicle comprising a sound diffuser device electrically connected to an audio system, remarkable in that said sound diffuser device is according to the invention and the audio system is configured to individually control, in particular by means of filter(s), several of the loudspeakers of each of the first network and the second network.

[0025] Advantageously, the sound diffuser device makes it possible to ensure the diffusion of sound over the entire audible frequency range (80 Hz - 20 kHz) so as to achieve 30 dB of attenuation. In fact, the sound diffuser device makes it possible, by means of the several loudspeakers, to emit audible sounds, at high frequencies above 800 Hz, to an occupant of a corresponding seat and to make these same sounds barely or not at all audible to the other occupant of the adjacent corresponding seat.

[0026] The invention makes it possible to considerably improve the perception of the “sound bubble” effect by the occupants, thus further enriching the sound experience in the motor vehicle.

[0027] Brief description of the drawings

[0028] [Fig 1] represents a front view of two sound diffusing devices according to the invention, each diffusing a sound towards a person occupying a support of said sound diffusing device; [Fig 2] represents a schematic view of different geometries of the first and second loudspeaker arrays of each of the sound diffusing devices of FIG. 1;

[0029] [Fig 3] represents a front view of the support of the sound diffuser device, preferably corresponding to a headrest of a motor vehicle seat;

[0030] [Fig 4] represents a perspective view of the headrest of Figure 3.

[0031] Detailed description

[0032] Figure 1 represents a front view of two sound diffuser devices 2 according to the invention, each diffusing a sound towards a person 4, 5 occupying a support 6 of said sound diffuser device 2.

[0033] The two supports 6 may correspond to adjacent seats of a motor vehicle and / or to an upper part of a back of said seats, or to headrests belonging to airplane seats or any other means of transport, or even to seats which may correspond to general public armchairs.

[0034] More preferably, the two supports 6 illustrated in FIG. 1 correspond to headrests 6 of two front seats of a motor vehicle interior 1.

[0035] Each headrest 6 comprises a front face 6.1 intended to accommodate the head of the occupant 4, 5, and two lateral faces 6.2, 6.4 to said front face 6, corresponding to a first lateral face 6.2 visible to the right of the front face 6.1, and to a second lateral face 6.4 visible to the left of the front face 6.1.

[0036] The sound diffuser device 2 comprises several loudspeakers 7 distributed in a first network 8 of loudspeakers and a second network 10 of loudspeakers preferably arranged on the lateral faces 6.2, 6.4 and oriented in a convergent manner towards a personalized listening zone 12, 14.

[0037] With reference to the right part of figure 1, a right listening zone 12 will be distinguished, and with reference to the left part of figure 1, a left listening zone 14 will be distinguished.

[0038] Each loudspeaker 7 comprises a main direction perpendicular to the lateral face 6.2, 6.4 and converging towards the listening zone 12, 14. In this configuration, the loudspeakers 7 of the first network 8 are oriented towards a first sub-zone 12.1, 14.1 of the listening zone 12, 14 and the loudspeakers of the second network 10 are oriented towards a second sub-zone 12.2, 14.2 of said listening zone 12, 14.

[0039] Preferably, the several loudspeakers 7 converge in order to form the first listening sub-zone 12.1, 14.1 so that it is distant from the second listening sub-zone 12.2, 14.2 by a distance of between 15 and 30 cm, thus corresponding to a gap between the two ears of the occupant 4, 5.

[0040] Each of the first 8 and second 10 networks of loudspeakers 7 comprises at least three loudspeakers 7, preferably at least five, more preferably at least six loudspeakers. Indeed, the number of loudspeakers 7 on each lateral face 6.2, 6.4 of the headrest 6 can be up to 16 loudspeakers 7, as in the configuration illustrated in FIG. 1.

[0041] Preferably, each loudspeaker 7 is capable of reproducing sounds having higher frequencies between 800 Hz and 20 kHz, more preferably between 900 Hz and 20 kHz.

[0042] Each loudspeaker 7 comprises its own enclosure and an average diameter of less than 30 mm. Preferably, the average diameter of the loudspeakers 7 is between 15 mm and 25 mm.

[0043] The sound diffuser device 2 of the invention further comprises a low-frequency loudspeaker 16 arranged adjacent to each of the first 8 and second 10 arrays of loudspeakers 7. Preferably, the low-frequency loudspeaker 16 has an average diameter of less than 60 mm, more preferably of approximately 50 mm, and is capable of reproducing low-frequency sounds between 80 Hz and 1 kHz.

[0044] The motor vehicle 1 comprises an audio system (not shown) electrically connected to the two illustrated sound diffuser devices 2, and makes it possible to individually control each loudspeaker 7 of the first 8 and second network 10.

[0045] In this regard, the audio system comprises a processor, and each loudspeaker 7 comprises an analog or digital filter. The audio system drives the loudspeakers 7 as well as the low-frequency loudspeakers 16 and adapts the filters according to the environment by means of a field control algorithm, for example of the “Pressure Matching” type, executed by the processor of the audio system.

[0046] Preferably, the device 2 of the invention comprises at least one microphone making it possible to acquire acoustic information from the environment in order to control the pressure field in the two listening zones 12 and 14.

[0047] Then, the processor recalculates the different filters of the 7 speakers in order to optimize or adapt them to achieve the sound bubble effect.

[0048] The processor uses algorithms to select the target sound field and then identifies light and dark areas. These correspond, for example, to listening zones 12 and 14 respectively.

[0049] The light zone 12 is the one in which the sound will be broadcast, while the dark zone 14 is the one in which the sound will be minimized in order to ensure an attenuation of approximately 30 dB (the term “approximately” here designates ±10% of the nominal value) between the light zone 12 and said dark zone 14.

[0050] In this regard, and following the identification of the two light 12 and dark 14 zones, a calculation of the audio filters to be applied to each loudspeaker 7 is carried out.

[0051] Advantageously, applying the audio filters independently to the speakers 7 makes it possible to generate a sound bubble at the level of the clear listening zone 12.

[0052] Alternatively, for other musical content, the left listening area 14 may correspond to a light area and the right listening area 12 may correspond to a dark area.

[0053] By superimposing these two states, zones 12 and 14 can be simultaneously clear for two different sound contents, while minimizing disturbances and / or mixing of one content with the other.

[0054] Advantageously, two sound bubbles are then obtained at listening zones 12 and 14, with an attenuation of at least 30 dB between the two. Thus improving the sound experience of occupants 4 and 5.

[0055] Figure 2 represents a schematic view of different geometries of the first 8 and second 10 loudspeaker networks 7 of each of the sound diffusing devices of Figure 1. Preferably, the several loudspeakers 7 of each of the two networks 8 and

[0056] 10 are arranged side by side so as to form at least one of the following geometries: square 18 or vertical 19 or triangular 20 or a combination 21 of at least two of said geometries.

[0057] Advantageously, these different geometries 18, 19, 20, 21 make it possible on the one hand to shape the shape and position of the listening sub-zones 12.1, 12.2, 14.1, 14.2 illustrated in figure 1. This makes it possible to ensure a sound directivity which adapts to the environment of the support, said geometries also allow the loudspeakers 7 to be easily integrated on the corresponding support while retaining the desired aesthetic appearance.

[0058] Figure 3 represents a front view of the support 6 of the sound diffuser device 2.

[0059] Preferably, the first 8 and second network 10 of loudspeakers 7 are symmetrical, and are also arranged symmetrically on each of the lateral faces 6.2, 6.4 relative to a central longitudinal axis of the headrest 6.

[0060] It can be seen that the low-frequency loudspeakers 16 are arranged at the opposite ends of the side faces 6.2, 6.4 so as to bring the loudspeakers 7 closer to the front face 6.1. This arrangement is advantageous because it makes it possible to bring the diffusion of high-frequency sounds closer and concentrate them as close as possible to the occupant's ears, so as to gain natural attenuation of the sound in the environment of the device 2, helping favorably to achieve the 30 dB of attenuation necessary for the perception of sound bubbles.

[0061] Figure 4 shows a perspective view of the headrest of Figure 3.

[0062] It is possible to observe here a curvature of the lateral face 6.4. Indeed, each of the lateral faces 6.2, 6.4 preferably comprises a curvature (around a transverse direction) so as to allow the loudspeakers 7 to accentuate the sound directivity towards the ears of the occupant.

[0063] In this respect, the curvature of the side face 6.2 can be defined by a radius of curvature of at least 50 mm and up to 600 mm.

[0064] It can be seen that the networks 8, 10 comprise a combination of square and vertical geometries, so as to conform to the architecture of the headrest 6 and advantageously allow the loudspeakers 7 to extend vertically and transversely on the side faces 6.2, 6.4 in order to take maximum advantage of the curvature to maximize the concentration of sounds towards the occupant's ear.

[0065] Preferably, the loudspeakers 7 comprise a rear enclosure 22 forming a load volume, said rear enclosure 22 being arranged directly at the rear of the lateral faces 6.2, 6.4 and formed with the headrest 6. The rear enclosure 22 advantageously ensures sealing and thus guarantees non-disturbance of the rear wave on the front wave.

[0066] Advantageously, the sound diffusion device of the present invention makes it possible to best understand the reflections & diffractions of sound due to the acoustic environment and to achieve optimal “isolation” levels, even in a complex environment such as a motor vehicle interior, in order to be able to offer an effective sound bubble experience to the occupants, and this over a wide range of audible frequencies (80 Hz - 20 kHz).

Claims

CLAIMS [Claim 1.] Sound diffuser device (2), comprising: - a support (6); and - several loudspeakers (7) arranged on the support (6) and oriented convergently towards a listening area (12, 14); characterized in that the several loudspeakers (7) are distributed into a first network (8) of loudspeakers (7) and a second network (10) of loudspeakers (7), said first network (8) and said second network (10) being convergent. [Claim 2.] Sound diffuser device (2) according to claim 1, in which the support (6) comprises a first face (6.2) on which the first network (8) of loudspeakers is arranged, and a second face (6.4) on which the second network (10) of loudspeakers (7) is arranged, said first face (6.2) and said second face (6.4) being oriented in converging main directions. [Claim 3.] Sound diffuser device (2) according to one of claims 1 and 2, in which the first network (8) of loudspeakers (7) and the second network (10) of loudspeakers (7) each comprise at least three loudspeakers (7). [Claim 4.] Sound diffuser device (2) according to one of claims 1 to 3, in which each loudspeaker (7) has an average diameter of less than 30 mm and is capable of reproducing sounds between 800 Hz and 20 kHz. [Claim 5.] Sound diffuser device (2) according to one of claims 1 to 4, in which the loudspeakers (7) of the first network (8) are oriented towards a first sub-zone (12.1, 14.1) of the listening zone (12, 14) and the loudspeakers (7) of the second network (10) are oriented towards a second sub-zone (12.2, 14.2) of the listening zone (12, 14), separate from the first listening sub-zone (12.1, 14.1). [Claim 6.] Sound diffuser device (2) according to claim 5, in which the first listening sub-zone (12.1, 14.1) is distant from the second listening sub-zone (12.2, 14.2) by a distance of between 15 and 30 cm, so as to correspond, respectively, to the two ears of a person (4, 5). [Claim 7.] Sound diffuser device (2) according to one of claims 5 and 6, in which the loudspeakers (7) of the first network (8) have different and converging orientations and / or the loudspeakers (7) of the second network (10) have different and converging orientations. [Claim 8.] Sound diffuser device (2) according to one of claims 1 to 7, in which each of the loudspeakers (7) of the first network (8) and / or of the second network (10) comprises a rear enclosure (22) forming a load volume. [Claim 9.] Sound diffuser device (2) according to one of claims 1 to 8, in which the support (6) is a headrest (6), in particular of a seat, and / or an upper part of a backrest of the seat, said support (6) further comprising a low-frequency loudspeaker (16) arranged adjacent to each of the first (8) and second array (10) of loudspeakers (10). [Claim 10.] Motor vehicle (1) comprising a sound diffuser device (2) electrically connected to an audio system, characterized in that said sound diffuser device (2) is according to one of claims 1 to 9 and the audio system is configured to individually control, in particular by means of filter(s), several of the loudspeakers (7) of each of the first network (8) and the second network (10).

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