Headrest Speaker Arrangement
Description
The present invention relates to a headrest for a vehicle seat and to a speaker box, which is
configured to be attached to a vehicle seat or to a headrest, and having at least one inclined
arranged speaker integrated in the headrest or in the speaker box.
In the US Patent US 7, 424,127 Bl a seat mounted speaker is described. The back of the
seating device comprises two electro-acoustical transducers orientated such that the
respective axis are substantially vertical to a user's head sitting on the seating device. The
axis of an electro-acoustical transducer refers to the axis of the radiating surface, i.e. it
typically points to the primary direction of radiation. The electro-acoustical transducers are
mounted in a headrest attached to a seating device. The electro-acoustical transducers are
situated in the headrest such that one transducer is on each side of a user's head when the
user is sitting in the seating device. The transducers are used to facilitate for directional
audio signal, such as left and right stereophonic device, which are emitted axial to the
headrest in a passenger's compartment. This means, it is an object of the US-patent that a
passenger in the vehicle can localize an audio signal, and therewith the position of a
speaker in the vehicle. Therefore, the patent refers to a seat mounted speaker which is
configured to improve a desired localization of an emitted sound signal.
In contrast, it is an object of the present invention to generate a desired diffuse sound cloud
in a passenger's compartment, for example, in an automobile interior. Thus, a passenger in
a vehicle may have a diffuse de-correlated sound perception compared to the directed
surround sound perception described in the US-Patent. This object is achieved by the
subject matter defined by the claims 1 and 2 1 and by the corresponding dependent claims 2
to 20 and 22 to 24.
According to embodiments of the invention, a headrest or a speaker box, which is
attachable to the vehicle seat or to a headrest comprises at least one integrated speaker
which is fixed in such a way that a main sound emission direction is inclined with respect
to a backrest main direction of the vehicle seat.
According to other embodiments, at least two speakers integrated in the headrest or in the
speaker box are lowered arranged in the headrest or in the speaker box so that a desired
diffuse sound cloud can be generated in a passenger's compartment by mixing the sound
waves of the at least two speakers during operation in a chamber formed by lowered
speakers and the side walls in the headrest or speaker box.
In a further embodiment, integrated speakers are completely lowered arranged in the
headrest or in the speaker box so that the headrest for a vehicle seat or a speaker box can
generate a complete diffuse sound irradiation or cloud during operation.
According to other embodiments, at least one speaker is arranged in the headrest or in the
speaker box so that it irradiates at least one wall in the headrest or in the speaker box.
According to another aspect, a vehicle comprises at least one vehicle seat with a headrest
or a speaker box to be attached to the vehicle seat or to the headrest as claimed herein and
further a dedicated sound wave reflector arranged above on a vehicle ceiling.
Brief Description of the Drawings
Fig. l a shows a schematic side view of a headrest of a vehicle seat according to an
embodiment of the invention.
Fig. lb shows another side view of a headrest of a vehicle seat according to an
embodiment of the invention.
Fig. l c shows a schematic side view of a speaker box attached to a headrest according to
an embodiment of the invention.
Fig. 2 shows a schematic side view of a vehicle seat and the corresponding angles between
a seating surface of the vehicle seat and a backrest of the seat and between a main sound
emission direction of the speaker and the backrest main direction.
Fig. 3a shows a schematic side view of a headrest or speaker box comprising inclined
speakers according to embodiments of the invention.
Fig. 3b shows a schematic top view of the headrest or speaker box according to Fig. 3a, the
headrest or the speaker box comprises two speakers arranged inclined in the headrest or in
the speaker box.
Fig. 3c shows a schematic back view of the headrest or speaker box according to Figs. 3a-
3b.
Fig. 3d shows another schematic back view of a headrest or a speaker box comprising two
speakers inclined to each other and to an assumed backrest main direction.
Fig. 3e shows another schematic back view of a headrest or a speaker box comprising two
speakers; one speaker irradiating upwards and the other speaker downwards.
Fig. 3f shows a schematic top view of a headrest and a passenger's head, as well as
different schematic inclined main sound emission directions with respect to a backrest
main direction.
Figs. 4a-4e show different embodiments of a headrest or a speaker box to be attached to a
vehicle seat or to a headrest, wherein the speakers have a different arrangement in the
headrest or in the speaker box.
Fig. 5 shows a schematic side view of a vehicle comprising a dedicated sound wave
reflector arranged on the vehicle ceiling according to embodiments of the invention.
Fig. 6 shows an embodiment of a sound wave reflector attached to a vehicle ceiling in an
automobile.
Fig. 7 shows a headrest of a vehicle seat with two integrated speakers lowered arranged in
a chamber of the headrest according to an embodiment of the invention.
Fig. 8 shows a further headrest of a vehicle seat with integrated lowered speakers and bass
reflex tubes according to an embodiment of the invention.
Detailed Description of the Embodiments
As reference to the accompanying Figures 1 to 8, explanations and embodiments relating
to a headrest for a vehicle seat or a speaker box to be attached to the vehicle seat or to a
headrest are given.
In embodiments of the invention, a headrest of a vehicle seat or a speaker box to be
attached to the vehicle seat or to a headrest is described. The headrest may be a headrest
for a vehicle seat, wherein the vehicle seat may be used, for example, in automobiles, in
buses, in trains, in airplanes, in ships, in subways and so on. The speaker box may be
configured to be attached to such a vehicle seat or to a usual headrest of a vehicle seat.
This means, the speaker box can be removed and fixed again, for example, mechanically
by a certain fixture, magnetically or by other appropriate means to a vehicle seat or a usual
headrest. The speaker box can be, for example fixed at a backside of a backrest of the
vehicle seat.
The headrest or the speaker box may comprise at least one integrated speaker, wherein the
speaker has a certain main sound emission direction during operation. The main sound
emission direction can be the normal to the membrane of the speaker. A sound wave may
mostly irradiated in the main sound emission direction during operation. The portion of a
sound wave which is irradiated by the speaker in the main sound emission direction may
depend on the frequency of the sound wave. Sound waves with a higher frequency may be
more directed emitted than sound waves with low frequencies. This means, the portion of a
sound wave which is emitted in direction of the main sound emission direction may be
higher than a portion of a sound wave with low frequencies (e.g. 10 - 500 Hz).
The headrest and also the speaker box may comprise electrical connections and contacts,
such that a certain sound or speech can be emitted via the integrated speaker by means, for
example, of an audio sound system, a navigation system, a CD/DVD or Blu-ray-player, a
MP3-player, a mobile phone and so. The speaker may be an electro-acoustical transducer.
This means, the speaker which is integrated in the headrest or in the speaker box is
configured to emit or irradiate upon an electrical signal a sound wave. The speaker may be
configured to emit, for example, music, speech or tones in a frequency range between, e.g.
10 Hz to 22.000 Hz.
The speaker may have a certain main sound emission direction, wherein the speaker is
fixed in the headrest or in the speaker box in such a way that the main sound emission
direction is inclined with respect to a backrest main direction of a backrest of the vehicle
seat. In other words, there is a certain angle a between the main emission direction of the
speaker and a backrest main direction on which the headrest or the speaker box is mounted.
The backrest main direction may be given by the axial direction of the backrest of the
vehicle seat. Changing the angle of the backrest with respect to a seating surface of the
vehicle seat may result in a change of the axial direction of the backrest main direction in
the space. But, the angle between the main sound emission direction and the backrest main
direction may be unchanged, since the integrated speaker in the speaker box or the headrest
may be tilted in the same way as the backrest.
In some embodiments the backrest main direction may be given by the normal of a bottom
plate wall or lower side of the speaker box or the headrest. In some embodiments the
backrest main direction may be given by the normal of a top side wall or upper side of the
speaker box or the headrest. Such a backrest main direction may be an assumed backrest
main direction indicating, that the normal may be identical to the backrest main direction if
the headrest is mounted to the vehicle seat or if the speaker box is fixed at a headrest or
directly to the backrest of the vehicle seat.
In Fig. la, a schematic side view of a headrest 10 of a vehicle seat is depicted. The
headrest 10 may comprise a front side area 8 for a passenger's head. The headrest 10 may
further comprise a box or a chamber 9 with an integrated speaker 20. In some
embodiments the headrest may comprise four side walls 10a, a top side wall 10b and
opposite to the top side wall 10b a bottom plate wall 10c.
According to embodiments, at least one speaker, two speakers, three speakers, four
speakers or a plurality of speakers may be integrated in the chamber or box 9 of the
headrest 10 or in a speaker box. The headrest 10 with the integrated speaker 20 may
comprise a sound outlet opening 13 at a top side wall 10b of the headrest 10. The speaker
20 comprises a main emission direction 25, wherein the speaker is fixed in the headrest in
such a way that the main sound emission direction 25 is inclined with respect to the
backrest main direction 30 of the backrest 15 of the vehicle seat. The main sound emission
direction 25 may be inclined by an angle a with respect to the backrest main direction 30.
The headrest may be fixed by means of a headrest support 16 to the backrest 15. Electrical
connections for the activation of the speaker may be routed via the headrest support 16 to
the at least one speaker 20 in the headrest 10. During operation of the speaker 20, sound
may be emitted mainly in the main sound emission direction 25. The sound waves can
escape from the headrest 10 through a sound outlet opening 13 in the headrest. The sound
waves are emitted into the environment, for example, into an automobile interior or a
passenger's compartment. A sound outlet opening can be simply formed by a missing topside
wall 10b or appropriate openings in the top-side wall 10 b or an side wall 10a.
Fig. l b shows the schematic side view of an headrest 10 with integrated speaker 20
according to another embodiment of the invention. According to this embodiment, a
chamber 9 which comprises the speaker 20 is fully integrated in the headrest 10. The
speaker is fixed again in the headrest in such a way that the main sound emission direction
25 is inclined with respect to a backrest main direction 30 of a backrest 15 of a vehicle
seat. The headrest may comprise again an opening - a sound outlet opening 13 - so that
during operation sound can be emitted into the vehicle interior.
In Fig. 1c a schematic side view of a speaker box which is attached to an normal headrest
11 is depicted. In other embodiments the speaker box may be attached to a vehicle seat, for
example, to a backrest of the vehicle seat. The speaker box 12 may comprise at least one
speaker 20 integrated in the speaker box 12. The speaker 20 has a main sound emission
direction 25 which is inclined by an angle a with respect to a backrest main direction 30 of
a backrest 5 of the vehicle seat. The backrest main direction 30 may be given by the axial
direction which the backrest points to.
In some embodiments the speaker box may comprise four side walls 12a, a top side wall
12b and opposite to the top side wall 12b a bottom plate wall 12c.
The speaker box 12 may be attached to the headrest or in alternative embodiments also to
the backrest itself by fixing means 23. Such fixing means may be, for example, mechanical
means like hooks, belts or a hook and loop fastener. The integrated speaker may be
inclined in such a way that the main sound emission direction 25 points away from a
passenger's head 22. According to other embodiments, the speaker may be inclined with
respect to a backrest main direction such that the main sound emission direction 25 points
in the direction of a passenger's head 22.
In an embodiment, the speaker 20 may be arranged so that the main sound emission
direction 25 points in any direction, except in a parallel direction to the backrest main
direction. This means, the main sound emission direction may be located on a cone formed
around the backrest main direction 30, wherein the main sound emission direction is tilted
by an angle a against the backrest main direction 30. But the main sound emission
direction may be different to the axial direction of the backrest seat.
According to further embodiments, the main sound emission direction of a speaker may
also point in direction to a bottom plate wall 12c of a speaker box 12 or a headrest 10.
According to some embodiments, the speaker 20 may be fixed in the headrest or in the
speaker box 12 in such a way that the main sound emission direction 25 is inclined by an
angle a with respect to a backrest main direction of a backrest of the vehicle seat. The
angle a between the main sound direction 25 of the speaker 20 and the backrest main
direction 30 can be, for example, equal or larger than 25°, 30°, 45° degrees or 90°. The
angle a may be between 25° and 155°, between 30° and 150° or between 45° and 135°.
The speaker 20 may be arranged in the headrest respectively in the chamber 9 of the
headrest 10, or in the speaker box, such that it irradiates at least one wall in the headrest,
respectively the chamber 9 of the headrest or in the speaker box 12. Sound waves 40 (see
Fig. 4) which are emitted during operation of the speaker may be partly reflected at a wall
in the headrest, respectively the chamber 9 of the headrest or in the speaker box 12, and
partly the sound waves may be directly emitted through a sound outlet opening 13 without
being reflected.
As it is shown in the schematic side view in Fig. 2a, a vehicle seat 8 may comprise a
seating surface 35 and a backrest 15, wherein the inclination of the backrest 15 to the
seating surface 35 can be characterized by an angle b. The position of the backrest and
therefore also the headrest mounted to the backrest can be changed with respect to the
seating surface 35. The speaker 20 in the headrest 10 or in the speaker box 20 may
comprise a fixed inclined main sound emission direction 25 with respect to the changeable
backrest main position 30.
In Fig. 3a, a schematic side view of a headrest 10 or speaker box 12 is depicted. The
speaker 20 is integrated in the headrest 10 or in the speaker box 12. The speaker is fixed in
the headrest, for example, in a board or fixture 28, such that the main sound emission
direction 25 is inclined with respect to a bottom plate wall 10c of a headrest or a bottom
plate wall 12c of a speaker box. A center 2 1 of the speaker 20 may comprise a distance D2
or Dl to a sound outlet opening 13 of the headrest 10 or the speaker box 12.
According to another embodiment, the center 2 1 of the speaker 20 may comprise a
distance D2 to a top edge 14 of the headrest or speaker box. The distance D2 or Dl may be
at least 3 cm, 4 cm or 5 cm. This means, according to embodiments, at least one speaker 20
may be lowered arranged in the headrest 10 or in the speaker box 12. The distance Dl from
the center 2 1 of the at least one speaker 20 to the sound outlet opening 13 may be at least 3
cm, 4 cm or 5 cm. The speaker 20 may be lowered arranged in the headrest 10 or in the
speaker box 12 with respect to a top edge 14 of the headrest or of the speaker box 12.
Fig. 3b shows the schematic top view of the headrest or speaker box according to Fig. 3a.
In this embodiment, a further speaker 20b is shown, which is integrated in the headrest or
speaker box besides the at least one speaker 20a. A missing top side wall 10b, 12b may
serve as a sound outlet opening 13. The missing top side wall 10b, 12b of the speaker box
or the headrest, respectively headrest chamber may serve as a sound outlet opening 13, so
that a sound wave can be emitted through the missing top side wall 10b, 12b of the
headrest or speaker box. In some embodiments a sound outlet opening 13 may be formed
by certain openings, like holes or slots in a wall of the headrest or speaker box. The sound
outlet opening may be adapted for sound waves to escape. The sound outlet opening may
be covered, for example, with fabric or a plastic cover to protect the speaker mechanically
and from dust. The first 20a and the second 20b speaker may be embedded into a board or
fixture 28 so that the main sound emission directions 25 of the speakers is inclined with
respect to a backrest main direction of a backrest. In some embodiments the speakers are
inclined to a normal of the bottom plate wall 10c, 12c of the headrest or the speaker box.
The normal can be considered as an assumed backrest main direction.
In Fig. 3c, a schematic back side view of the tilted first and second speaker 20a and 20b
arranged in the board 28 is shown.
Fig. 3d, shows another schematic back side view of a headrest or a speaker box with two
integrated speakers. In this embodiment, the first speaker 20a and the second speaker 20b
are not arranged parallel to each other. Instead, both speakers are inclined to a backrest
main direction 30 or to the normal of the bottom plate wall 10c, 12c of the headrest or
speaker box. The first main sound emission direction 25a of the first speaker 20a is
inclined to the backrest main direction 30 by a first angle cel. Angle a l may be equal or
larger than 10°, 20°, 25°, 30°, 45° or 90°. The second main sound emission direction 25b
of the second speaker 20b is inclined to the backrest main direction 30 by a second angle
a2. Angle a2 can be roughly, for example, equal to 360° - al.
According to an embodiment, which is schematically depicted in Fig. 3e, an angle a l
between a first main sound direction 25a of a first speaker 25a and a backrest main
direction 30 is equal or larger than 10°, 20°, 25°, 30°, 45° or 90° and an angle a2 between a
second main sound direction 25b of a second speaker 20b and the backrest main direction
30 is equal to 180° + al. The fixture or board 28 may have openings 32, so that a sound
wave which is downwards emitted by the second speaker 20b can be reflected in the
speaker box and leave the speaker box via the openings 32. It should be noted, that in other
embodiments of the invention, the relation between angle a l and a2 can be different. The
first speaker and the second speaker need not to be arranged symmetrically with respect to
each other. This means, the speakers can be randomly or asymmetrically arranged with
respect to each other in the headrest 10 or in the speaker box 12.
In Fig. 3f, a schematic top view of a headrest 10 and a passenger's head 22, as well as,
arrows, which illustrate possible main sound emission directions 25, and the backrest main
direction 30 are shown. The backrest main direction 30 may be perpendicular with the
sheet plane, i.e. the backrest main direction may perpendicular point out of the sheet plane.
In general, a main sound emission direction 25 may point in any direction with respect to
the head 22 of the passenger, as long as, the main sound emission direction 25 is inclined
with respect to the backrest main direction 30. The backrest main direction 30 may be
roughly parallel to the spine of a passenger sitting on the vehicle seat.
In the following, with respect to the embodiments shown in Figs. 4a-4e, only schematic
speaker boxes 12 are depicted and described. However, the described embodiments are
also applicable to a headrest 10, respectively a chamber 9 of the headrest 10, so that the
embodiments also refer to the inventive headrest 10.
In Fig. 4a, an embodiment of a speaker box 12 to be attached to a vehicle seat or to a
headrest is depicted. In this embodiment, a first 20a and a second 20b speaker are arranged
in a speaker box 12, such that a sound wave 40 is partly emitted in direction to a bottom
plate wall 12c of the speaker box and partly to an inner wall 12a of the speaker box.
The speaker box 12 may have a sound outlet opening 13 at the top side of the speaker box
12. In this embodiment the sound outlet opening 13 may be formed by a missing top side
wall 12c of the box 12. The speakers 20a, 20b may be arranged in a fixture or board 28
inside of the speaker box, so that the main sound emission directions of the first and the
second speaker are inclined with respect to a backrest main direction 30 or to a normal of
the bottom plate wall 12a of the speaker box.
The board or fixture 28 may be configured to fix the speakers 20a, 20b in a desired
position in the speaker box. The speakers 20a, 20b are lowered arranged with respect to a
top edge 14 of the sound outlet opening 13 of the speaker box 12. The same is applicable
to embodiments which are directed to a headrest 10 of a vehicle seat.
According to embodiments, the at least one speaker 20 can be arranged in the headrest 10
or in the speaker box 12 in different ways. In Fig. 4b, another example of a first 20a and a
second 20b speaker which are fixed in a speaker box 12 in such a way that the main sound
emission direction 25 is inclined with respect to a backrest main direction 30 of a backrest
15 of a vehicle seat or with respect to an assumed backrest main direction 30, like the
normal of the bottom plate wall 12a or the normal of the top side wall 12b of the speaker
box 12 is shown. In this embodiment, the speakers 20a, 20b are inclined upwardly in
contrast to the embodiment in Fig. 4a, where the speakers are turned downwards, pointing
to a bottom plate wall 12c. At least one speaker may partly irradiate a wall, respectively a
inner wall of a headrest or speaker box, so that a partly reflected sound wave 40 can escape
through a sound outlet opening 13.
According to embodiments, a headrest 10 of a vehicle seat or a speaker box 12 to be
attached to the vehicle seat or to an usual headrest 11 may comprise at least one speaker 20
wherein the speaker is arranged in the headrest or in the speaker box 12 so that it irradiates
at least one wall 12a, 12b, 12c of a speaker box 12 or headrest 10.
In the embodiment described in Fig. 4b, the sound outlet opening 13 consist of two slots
13a and 13b in the top side wall 12b of the speaker box 12. In other embodiments the
sound outlet opening 13 may have a different shape and it may be formed in a different
wall 10a, 12a, 10b, 12b or 10c, 12c of the speaker box 12 or headrest 10.
According to some embodiments, a headrest 10 or a speaker box 12 comprises a sound
outlet opening 13, wherein the at least one speaker 20 is arranged in the headrest or
speaker box so that during operation a sound wave emitted in the main sound direction 25
is reflected from at least one wall in the headrest or in the speaker box and is emitted
through the sound outlet opening 13.
In Fig. 4b, it is schematically illustrated how a sound wave 40 is reflected from an inner
wall 12a, and how the sound wave 40 escapes through the sound outlet opening 13b. In this
embodiment, the main sound directions 25a, 25b of the two speakers 20a and 20b are
pointing away from an assumed backrest main direction 30.
In contrast, in Fig. 4c the main sound emission directions 25a and 25b of the respective
first and second speaker 20a and 20b are pointing towards an assumed backrest main
direction 30. An emitted sound wave 40 can directly escape through the sound outlet
opening 13 of the speaker box 12.
For passengers listening to the emitted sound wave, a desired diffused sound cloud can be
generated in a passenger compartment. For that reason, the speakers 20 can be lowered
arranged in the speaker box 12, and hence at least a partial mixing of the emitted sound
waves of the speakers 20a and 20b takes place in an upper chamber space 17 of the speaker
box. Thus, a complete de-correlation of the emitted sound waves can be achieved. The
same can be achieved in embodiments for the inventive headrest 10.
As it is shown in Figs. 4a-4e, if the speakers are lowered arranged in the speaker box 12 or
in a headrest 10, direct and/or reflected sound waves can be mixed in a chamber space so
that for a listener, a complete diffuse sound cloud may be generated in a passenger
compartment. In contrast to a highly directive emission of a sound waves, speakers 20
which are lowered in a speaker box 12 or headrest 10 can be configured to generate a
decorrelated and diffuse sound perception. A listener may not be able to locate the position
of the speakers so that a diffuse sound cloud is achieved in a passengers compartment.
In Fig. 4d, three speakers 20a-20c are arranged in the speaker box 12 so that the main
sound emission directions 25a, 25b and 25c are directed to the side walls 12a, respectively
to the bottom plate wall 12c of the speaker box 12. The main sound emission directions
25a, 25b and 25c can be mainly directed perpendicular to the walls. In other embodiments
the main sound emission direction can be different than perpendicular to the wall. In
general, the main sound emission direction may comprise a certain angle with respect to a
normal of the wall. The speakers 20a-20c are arranged in a fixture 28 which is build into
the speaker box 12. The speakers 20a and 20b may be, for example, tweeters and the
speaker 20c may be a woofer or a subwoofer. At least the speakers 20a and 20b may be
arranged inclined to an assumed backrest main direction 30. In this embodiment, the main
sound emission directions 25a and 25b and the assumed backrest main direction 30
comprise an angle of about 90°.
A first speaker 20a is arranged in the headrest 10 or in the speaker box 12, so that a sound
wave 40 emitted during operation in the main sound emission direction 25a irradiates an
inner side wall 12a in a perpendicular direction. A second speaker 20b is arranged in the
headrest 10 or in the speaker box 12 so that a sound wave emitted during operation in the
main sound emission direction 25b irradiates an inner bottom plate wall 12c of the headrest
or chamber in the headrest or in the speaker box. A third speaker 20c is arranged in the
headrest 10 or in the speaker box 12, so that a sound wave 40 emitted during operation in
the main sound emission direction 25a irradiates an inner side wall 12a in a perpendicular
direction.
The speakers 20a-20c may be completely lowered arranged in the headrest 10 or in the
speaker box 12, so that only reflected sound waves 40 escape through a sound outlet
opening. 13 at a top side of the speaker box. The escaping sound waves may be mixed
diffuse sound waves from the single speakers 20a - 20c. The top side of a box may be
defined by the sound outlet openings 13. This means, in some embodiments a side wall or
another wall of a headrest 10 or speaker box 12 may be considered as top side wall, if the
side comprises the sound outlet opening. In other embodiments the speaker box or the
headrest may comprise a plurality of sound outlet openings in one or more walls. A top
side wall may than be defined by the geometry or by the intended usage of the speaker box
or headrest. Emitted sound waves 40 of the speaker 20a-20c may be completely mixed, so
that an diffuse decorrelated sound impression can be achieved, for example, in an
automobile interior.
According to some embodiments, a headrest 10 of a vehicle seat 18 or a speaker box 1 , as
described above, may comprise at least two speakers lowered arranged in the headrest or in
the speaker box, so that during operation of the speakers sound waves emitted from the at
least two speakers are completely mixed in the headrest or in the speaker box. The decorrelated
mixed sound waves may escape from the headrest or the speaker box to the
environment.
In some embodiments, at least one speaker 20 may be arranged in the headrest or in the
speaker box so that it irradiates at least one inner wall in the headrest or in the speaker box.
In Fig. 4e, two speakers 20a and 20b are arranged in a speaker box 12. The speaker box 12
comprises four side walls 12a and one bottom plate wall 12c. A top side wall 12b of the
speaker box 12 is missing. The missing top side wall 12b acts as a sound outlet opening 13
for sound waves emitted from the speakers 20a and 20b during operation. The main sound
emission directions 25a and 25b of speakers 20a, 20b are inclined by an angle l and a2
with respect to an assumed backrest main direction 30.
In some embodiments the backrest main direction 30, respectively the assumed backrest
main direction is perpendicular to a bottom plate wall 12c, to a top side wall 12b or to a
sound outlet opening 1 . The speaker box 12, or at least the inner walls or the chamber 9 in
a headrest 10 can be made of a material which reflects the emitted sound waves 40 in a
proper way. This means, according to some embodiments, the loss of the reflected sound
waves at the inner walls of the speaker box 12 or in a chamber 9 in a headrest can be low.
Furthermore, in Fig. 4e, speaker 20b is arranged in the speaker box 12, so that a sound
wave 40 emitted in a main sound emission direction 25b irradiates a side wall 12a and a
bottom plate wall 12c of the headrest or of the speaker box 12. The sound wave 40 can be
emitted into the environment through a sound outlet opening 13 which is formed on a top
side 12b opposite to the bottom plate wall 12c of the headrest 10 or speaker box 12.
According to some embodiments of the invention, a headrest of a vehicle seat or a speaker
box to be attached to the vehicle seat or to a headrest, as described above, may comprise at
least a second speaker, which is symmetrically arranged to the at least one speaker in the
headrest or in the speaker box. In other embodiments the second speaker can be
asymmetrically arranged with respect to the at least one speaker in the headrest or in the
speaker box. During operation a decorrelated sound wave based on a mixture of the single
sound waves emitted by the at least one speaker and by the at least second speaker escapes
through a sound outlet opening into the environment, for example, into a passenger's
compartment like an automobile cabin.
According to some embodiments, the speaker box 12 or a chamber 9 of a headrest 10 may,
for example, have the shape of a polyhedron, a cube, a cuboid or a rectangular
parallelepiped having a top side wall, opposite to a bottom plate wall and a plurality of side
walls.
According to the embodiment in Fig. 4e, the headrest or the speaker box may comprise a
sound outlet opening 1 , wherein the at least one speaker 20a is arranged in the headrest or
speaker box so that during operation a sound wave 40 irradiates an inner side wall and a
sound outlet opening 13. The second speaker 20b is arranged in the headrest or in the
speaker box 12, so that a sound wave 40b emitted during operation in the main sound
emission direction 25b irradiates a side wall 12a and an inner bottom wall 12c of the
headrest of the speaker box, so that during operation a diffuse sound cloud which
comprises a mixture of the sound waves 40a', 40a" and 40b emitted by the at least one
speaker 20a and by the second speaker 20b escapes through the sound outlet opening 13.
Speaker 20a may be configured to emit a sound wave directly through a sound outlet
opening 13 in the surrounding area.
In Fig. 5, a schematic side view of a vehicle 100 according to other embodiments of the
invention is depicted. The vehicle 100 may comprise at least one vehicle seat 18 with a
headrest 10 of the vehicle seat 18 or a speaker box 12 to be attached to the vehicle seat 18
or to a headrest 1. The headrest 10 or the speaker box 12 may be configured as described
herein with respect to the Figs. 1 - 4e. The headrest 10 or the speaker box 12 may comprise
at least one speaker 20 integrated in the headrest 10 or in the speaker box 12, wherein the
speaker has a main sound emission direction 25 and wherein the speaker 20 is fixed in the
headrest 10 or in the speaker box 12 in such a way that the main sound emission direction
25 is inclined with respect to a backrest main direction 30 of the vehicle seat 18.
In addition, according to some embodiments, the vehicle 100 may further comprise a
dedicated sound wave reflector 50 arranged above the headrest 10 of a vehicle seat or
above a speaker box 12 on a vehicle ceiling 45. The sound wave reflector 50 may be
configured to reflect sound waves 40, which are emitted from the at least one speaker 20
integrated in the headrest or in the speaker box with a lower sound wave loss, than the
vehicle ceiling 45 in the vehicle. The sound waves 40 may be reflected from the sound
wave reflector 50 in the passenger's compartment, for example, an automobile interior, as
it is schematically shown in Fig. 5. The sound wave reflector 50 may have a curved
concave surface, for example, with a curvature so that a thickness D3 of the sound wave
reflector 50 or a distance D3 between the vehicle ceiling 45 and a vertex 5 1 of the sound
wave reflector 50 is in a range between 0.5 cm and 5 cm. The thickness at the vertex or the
distance D3 may be, for example, about 1cm according to some embodiments.
In general, the term vehicle as used herein may comprise, for example, an automobile, a
bus, a train, a plane, a ship, a subway and so on. This means, the term vehicle may include
any means of transportation in the air, on the water, on the earth or in the underground. The
vehicle or the means of transportation may comprise a passenger's compartment, which
includes a dedicated sound wave reflector 50 at a vehicle ceiling 45 as described herein.
The main sound emission direction 25 of the integrated speaker may be directed to the
sound wave reflector 50, so that during operation a sound wave irradiated from the at least
one speaker 20 is reflected from the sound wave reflector 50 into the vehicle interior 90.
According to some embodiments, the vehicle 100 may be configured to generate during the
operation of the at least one speaker integrated in the headrest or in the speaker box a
diffuse sound perception in the vehicle interior 90.
In Fig. 6, a photo of a vehicle interior 90 is depicted. Above a headrest 10, which is
attached to a vehicle seat 18, a sound wave reflector 50 is fixed at a vehicle ceiling 45. The
edges of the reflector area 50 above the headrest 10 are marked white.
In some embodiments, the sound wave reflector 50 has a rectangular shape wherein a
surface of the sound wave reflector is corrugated or curved so that a sound wave, which is
reflected from the sound wave reflector, is irradiated in the vehicle interior (see also
schematic Fig. 5).
In Fig. 7, a photo of a headrest 10 for a vehicle seat according to some embodiments is
depicted. In this embodiment, the headrest 10 comprises two speakers 20a, 20b, which are
lowered arranged in the headrest 10 or a chamber of the headrest. The distance D2, Dl
between a center 2 1 of the speaker and a top edge 14 of the headrest 10, respectively the
chamber edge 14 of the headrest or the sound outlet opening may be at least 3 cm, 4 cm or
5 cm. The top side wall 10b of the headrest or chamber for the speakers 20a, 20b is
missing, so that the missing top side wall serves as a sound outlet opening 1 for the sound
waves which are emitted in a passenger's compartment.
In Fig. 8, a photo of a headrest prototype for a vehicle seat according to another
embodiment is depicted. Beside the lowered arranged speakers 20a and 20b, the headrest
10, or also a speaker box 12 which can be attached to a vehicle seat or a to a headrest
comprises two bass-reflex tubes 65 so that the emitted sound in the low frequency range
sounds more deeper and saturated and therewith the sound quality and the sound
perception can be improved.
According to some embodiments disclosed herein, at least one speaker may be lowered
arranged in a headrest 10, respectively in a chamber 9 in the headrest 10 or in a speaker
box 12. In other embodiments of the invention, the at least one speaker 20 may not be
lowered arranged in the headrest, respectively in the chamber of the headrest or in the
speaker box. In this case, a center 2 1 of a speaker, for example, the center of the membrane
of the speaker, may have a distance D or D2 to a sound outlet opening 13 or to an top
edge 1 of the headrest, which is, for example, between 0 cm and 2 cm, between 0 cm and
3 cm, between 0 cm and 4 cm or between 0 cm and 5cm.
Embodiments of the invention concern a headrest speaker arrangement. A novel speaker
arrangement in headrests and the control of the same is described herein, which is
according to some embodiments for a three-dimensional sound reproduction, in small
space volumes, e.g. in a passengers compartment or an auto cabin, particular well
sufficient. According to some embodiments, two speakers are built-in in a headrest of a
seat, for example, a vehicle seat. If a vehicle comprises four seats, the two headrests of the
front seats are sufficient. The speakers can irradiate upwards to a ceiling of the vehicle.
According to some embodiments, below the ceiling of the vehicle above the headrest a
harder region than the surrounding usual vehicle ceiling is installed in order to achieve a
good reflection of the emitted sound waves. The harder region 50, may be, for example, a
plastic plate. The harder region 50 is described herein, also as a sound wave reflector 50
which may be mounted at the vehicle ceiling above the headrest. The surface of the sound
wave reflector can be slightly curved concave (about 1 cm), in order to support a diffuse
sound irradiation. The sound wave reflector may be curved concave, for example, in a
range between 0.5 cm and 5 cm. This means, the thickness D3 of the sound wave reflector
at the vertex 51, respectively apex of the concave sound wave reflector 50 or the distance
D3 from the vehicle ceiling 45 to the vertex 5 1 or apex of the concave sound wave
reflector 50 may be between 0.5 cm and 5cm. The size of the sound wave reflector may be,
for example, 340x180 mm.
According to other embodiments, the area of the sound wave reflector may be, for
example, between 200 cm2 and 1000 cm2 or between 100 cm2 and 2000 cm2. The sound
wave reflector may have, for example, a quadratic, a rectangular, a round or a trapezoid
shape. The usage of the headrests allows to use sufficient large speakers with a not too
small volume behind. This is necessary to achieve a sufficient lower cut-off frequency of,
from e.g. 150 Hz. In order to reproduce a de-correlated stereophonic signal per person, two
speakers per headrest have to be used. Above the speakers in the headrest there is one
common chamber space 17 for both speakers. The common chamber space 17 can be seen
in the Figs. 7 and 8.
Because of a lowering of the speakers with respect to a top edge 1 from at least 40 mm in
the headrest and by the mixture of both speaker signals in the resulting chamber 17 and by
the partial radiation above the reflector, the speaker itself cannot be localized and a desired
diffuse sound cloud from an upper side can be achieved. This applies for a person in front
of the headset, as well as, for a person behind the headrest on a rear seat with respect to the
sound perception. An extension of this sound cloud and a three-dimensional perception can
be achieved by other speakers in the reproduction space by the reproduction via further
pairs of de-correlated signals.
According to embodiments, the headrest of a vehicle seat or a speaker box as described
herein may be part of a larger audio sound system, which includes further speakers which
may be distributed in a vehicle's compartment.
Claims
Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat or to a headrest, comprising:
at least one speaker (20) integrated in the headrest (10) or in the speaker box (12),
wherein the speaker (20) has a main sound emission direction (25), and wherein the
speaker (20) is fixed in the headrest (10) or in the speaker box (12) in such a way
that the main sound emission direction (25) is inclined with respect to a backrest
main direction (30) of a backrest (1 ) of the vehicle seat (18).
Headrest (10) of a vehicle seat (18) or a speaker box (12) to be attached to the
vehicle seat (18) or to a headrest according to claim 1,
wherein an angle a between the backrest main direction (30) and a seating surface
(35) of the vehicle seat (18) is changeable, and wherein the speaker (20) fixed in the
headrest (10) or in the speaker box (12) comprises an inclined main sound emission
direction (25) relative to the changeable backrest main direction (25).
Headrest (10) of a vehicle seat or a speaker box (12) to be attached to the vehicle
seat or to a headrest, according to claim 1 or 2, wherein an angle a between the
main sound emission direction (25) of the speaker (20) and the backrest main
direction (30) is equal or larger than 25°, 30°, 45° or 90°.
Headrest (10) of a vehicle seat or a speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 3, comprising a first
speaker (20a) and a second speaker (20b), wherein the first speaker (20a) has a first
main sound emission direction (25a) and the second speaker (20b) has a different
second main sound emission direction (25b).
Headrest (10) of a vehicle seat or a speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to claim 4, wherein an angle l between the
first main sound emission direction (25a) and the backrest main direction (30) is
equal or between larger than 10°, 20°, 30°, 45° or 90° and an angle a2 between the
second main sound emission direction (25b) and the backrest main direction (30) is
equal to 180° + al.
Headrest (10) of a vehicle seat or a speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to claim 4, wherein an angle l between the
first main sound emission direction (25a) and the backrest main direction (30) is
equal or between larger than 10°, 20°, 30°, 45° or 90° and an angle al between the
second main sound emission direction (25b) and the backrest main direction (30) is
equal to 360° - al.
Headrest (10) of a vehicle seat or speaker box (12) to be attached to the vehicle seat
(18) or to a headrest according to one of the claims 1 to 6, wherein the at least one
speaker (20) is lowered arranged in the headrest (10) or in the speaker box (12)
with respect to a sound outlet opening (10c, 12c) of the headrest (10) or the speaker
box (12).
Headrest (10) of a vehicle seat or speaker box (12) to be attached to the vehicle seat
(18) or to a headrest according to claim 7, wherein a distance D of a center (21) of
the at least one speaker (20) and the sound outlet opening (10c, 12c) is at least 3
cm, 4 cm or 5 cm.
Headrest (10) of a vehicle seat or speaker box (12) to be attached to the vehicle seat
(18) according to one of the claims 1 to 8, wherein the at least one speaker (20) is
lowered arranged in the headrest (10) or in the speaker box (12) with respect to a
top edge (14) of the headrest or of the speaker (20) box.
Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to claim 7, wherein a distance D2 of a center
(21) of the at least one speaker (20) and the top edge (14) of the headrest (10) or
speaker box (12) is at least 3 cm, 4 cm or 5cm.
Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 10, comprising at least
a second speaker (20b) lowered arranged in the headrest or in the speaker box (12),
so that during operation sound waves (40) emitted from the at least first and second
speaker (20a, 20b) are mixed in a chamber (17) formed in the headrest or in the
speaker box (12).
12. Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat or to a headrest according to one of the claims 1 to 11, wherein the speaker
(20) is arranged in the headrest (10) or in the speaker (20) box to irradiate at least
one inner wall (lOf, 12f) in the headrest (10) or in the speaker box (12).
13. Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 12, wherein the
headrest (10) or the speaker box (12) comprise a sound outlet opening (10c, 12c)
and wherein the at least one speaker (20) is arranged in the headrest (10) or in the
speaker box (12), so that during operation a sound wave (40) emitted in the main
sound emission direction (25) is reflected from at least one inner wall (lOf, 12f) in
the headrest (10) or in the speaker box (12) escapes to the sound outlet opening
(10c, 12c).
14. Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 13, wherein the at least
one speaker (20) is arranged in the headrest (10) or in the speaker box (12), so that
a sound wave (40) emitted during operation in the main sound emission direction
(25) irradiates a side wall (lOf, 12f) and a bottom plate wall (10a, 12a) of the
headrest (10) or of the speaker box (12), wherein the sound wave (40) escapes
through a sound outlet opening (10c, 12c), which is arranged on a top side wall
(10c, 12c) , opposite to the bottom plate wall (10a, 12a) of the headrest (10) or
speaker box (12).
15. Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to claim 14, further comprising a second
speaker (20b) arranged to the at least one speaker (20a) in the headrest (10) or in
the speaker box (12), wherein during operation a de-correlated sound wave (40) of
a mixture of the sound waves (40a, 40b) emitted by the at least one speaker (20a)
and by the second speaker (20b) is emitted through the sound outlet opening (13).
16. Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 15, wherein the at least
one speaker (20) is arranged in the headrest (10) or in the speaker box (12), so that
a sound wave (40) emitted during operation in the main sound emission direction
(25) irradiates an wall of the headrest (10) or the speaker box (12) and a sound
outlet opening (13) so that a mixture of a direct sound wave and a reflected sound
wave is emitted through the sound outlet opening (13).
17. Headrest (10) of a vehicle seat (18) or a speaker box (12) to be attached to the
vehicle seat (18) or to a headrest according to one of the claims 1 to 16, wherein the
speaker box (12) is a polyhedron, a cube, a cuboid or a rectangular parallelepiped
having a top side wall, opposite to a bottom plate wall and a plurality of side walls.
18. Headrest (10) of a vehicle seat (18) or speaker box ( ) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 17, wherein a first
speaker (20a) is arranged in the headrest (10) or in the speaker box (12), so that a
sound wave (40) emitted during operation in the main sound emission direction
(25) irradiates a side wall , and wherein a second speaker (20) is arranged in the
headrest (10) or in the speaker box (12), so that the sound wave (40) emitted during
operation in the main sound emission direction (25) irradiates an bottom plate wall
(10a, 12a) .
19. Headrest ( 10) of a vehicle seat ( 18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 18, wherein the
headrest (10) or the speaker box (12) comprise a sound outlet opening (13) and
wherein the at least one speaker (20a) is arranged in the headrest (10) or in the
speaker box (12) so that during operation a sound wave (40) emitted in the main
sound emission direction (25a) irradiates an side wall (lOf, 12f) and the sound
outlet opening (13) and wherein a second speaker (20b) is arranged in the headrest
(10) or in the speaker box (1 ) so that a sound wave (40) emitted during operation
in the main sound emission direction (25) irradiates a side wall and a bottom plate
wall of the headrest (10) or of the speaker box (12), so that during operation a
diffuse sound wave (40) comprises a mixture of the sound waves emitted by the at
least one speaker (20) and by the second speaker (20) is escaping through the sound
outlet opening (13).
20. Headrest (10) of a vehicle seat (18) or speaker box (12) to be attached to the vehicle
seat (18) or to a headrest according to one of the claims 1 to 19, wherein the
headreast (10) or the speaker box (12) further comprise a bass reflex tube (65).
2 1. A vehicle (100) comprising:
at least one vehicle seat (18) with a headrest (10) of the vehicle seat (18) or a
speaker box (12) to be attached to the vehicle seat (18) or to the headrest (10),
wherein the headrest (10) or the speaker box (12) comprise:
at least one speaker (20) integrated in the headrest (10) or in the speaker (20) box,
wherein the speaker (20) has a main sound emission direction (25), and wherein the
speaker (20) is fixed in the headrest (10) or in the speaker (20) box in such a way
that the main sound emission direction (25) is inclined with respect to a backrest
main direction (30) of a backrest (15) of the vehicle seat (18),
and further comprising a dedicated sound wave reflector (50) arranged above the
headrest (10) of the vehicle seat (18) or a speaker box (12) on a vehicle ceiling (45),
wherein the sound wave reflector (50) is configured to reflect sound waves (40)
emitted from the at least one speaker (20) integrated in the headrest or in the
speaker box (12) with a lower sound wave loss than the vehicle ceiling (45) in the
vehicle (100).
22. The vehicle (100) according to claim 21, wherein the main sound emission
direction (25) is directed to the sound wave reflector (50), so that during operation a
sound wave (40) emitted from the at least one speaker (20) is reflected from the
sound wave reflector (50) into the vehicle interior (90).
23. The vehicle (100) according to claim 22, wherein the vehicle (100) is configured to
generate during the operation of the at least one speaker (20) integrated in the
headrest (10) or in the speaker box (12) a diffuse sound perception in the vehicle
interior (90).
The vehicle (100) according to one of the claims 2 1 to 23, wherein the sound wave
reflector (50) has curved concave surface, and wherein a thickness of the sound
wave reflector (50) at the vertex (51) or a distance D3 from the vehicle ceiling (45)
to the vertex (51) of the sound wave reflector (50) may be between 0.5 cm and 5cm.