Packaging of acoustic volume increasing materials for loudspeaker devices

Abstract

There is provided an acoustic element for placement in a sound path of a loudspeaker device, the acoustic element comprising a container and an acoustic volume increasing material located in the container. In an embodiment, the container comprises wall portions with different physical characteristics. In other embodiments, the walls of the container are made of the same material.

Claims

1. An acoustic element for placement in a back volume of an acoustic device, the acoustic element comprising: a three-dimensional container comprising a plurality of solid wall portions and a permeable wall, the plurality of solid wall portions defining an interior chamber, and the permeable wall is configured as a single wall of the container; and an amount of loose particles of an acoustic volume increasing material; wherein the acoustic volume increasing material is disposed in the interior chamber prior to the permeable wall being attached to seal the interior chamber, the permeable wall comprising a material that retains the acoustic volume increasing material within the interior chamber; wherein the plurality of solid wall portions comprise a material that substantially impedes gas exchange between the back volume and the interior chamber of the container; wherein gas exchange between the back volume and the interior chamber of the container occurs through the permeable wall, thereby allowing gases in the back volume to interact with the loose particles of the acoustic volume increasing material disposed within the container; and wherein the external surfaces of the plurality of solid wall portions of the three-dimensional container are configured to substantially conform to the internal surfaces of a predetermined portion of the back volume of the acoustic device in all three axes.

2. The acoustic element according to claim 1, wherein the acoustic volume increasing material comprises an electrically non-conductive zeolite-based material.

3. The acoustic element according to claim 1, wherein the plurality of solid wall portions of the three-dimensional container are plastic.

4. The acoustic element according to claim 1, wherein the plurality of solid wall portions of the three-dimensional container are formed by injection molding, thermo-forming, or deep drawing.

5. The acoustic element according to claim 1, wherein the interior chamber of the three-dimensional container is partially filled with the acoustic volume increasing material.

6. The acoustic element according to claim 1, wherein the interior chamber of the three-dimensional container is substantially filled with the acoustic volume increasing material.

7. The acoustic element according to claim 1, wherein the sound transmissibility of the plurality of solid wall portions is less than the sound transmissibility of the permeable wall.

8. The acoustic element according to claim 1, wherein the permeable wall has low acoustic resistance and comprises one or more of a filter material, a fleece material, a foam material, a sieve material, a mesh material, or a cloth fabric formed from fibers.

9. The acoustic element according to claim 8, wherein pores in the material of the permeable wall are adapted to be less than the particle size of the acoustic volume increasing material.

10. The acoustic element according to claim 1, wherein the shape of the three-dimensional container provides a predetermined spatial distribution of the acoustic volume increasing material within the back volume of the acoustic device.

11. The acoustic element according to claim 1, wherein the external surfaces of at least a portion of the permeable wall of the three-dimensional container are configured to substantially conform to the internal surfaces of a predetermined portion of the back volume of the acoustic device.

12. An acoustic element for the back volume of an acoustic device, the acoustic element comprising: a three-dimensional canister comprising a non-porous chamber portion coupled to an acoustically porous wall portion, wherein the acoustically porous wall portion is a single wall of the canister; and an amount of loose particles of an acoustic adsorber material disposed within the interior of the chamber portion; wherein the acoustic adsorber material is disposed in the chamber portion prior to the acoustically porous wall portion being attached to the chamber portion and sealing the canister; wherein the chamber portion comprises a material that substantially impedes gas transfer between the back volume and the interior of the chamber portion; wherein the acoustically porous wall portion comprises a material that facilitates gas transfer between the back volume and the interior of the chamber portion so gas in the back volume can interact with the particles of acoustic adsorber material disposed within the chamber portion; and wherein the exterior surfaces of at least the chamber portion of the canister are configured to substantially conform to the internal surfaces of a predetermined portion of the back volume of the acoustic device in all three axes.

13. The acoustic element according to claim 12, wherein the acoustic adsorber material comprises particles of a zeolite-based sound adsorber.

14. The acoustic element according to claim 12, wherein the acoustic adsorber material comprises particles of an electrically insulating sound adsorber.

15. The acoustic element according to claim 12, wherein the chamber portion of the three-dimensional canister is plastic.

16. The acoustic element according to claim 12, wherein the chamber portion of the three-dimensional canister is formed by injection molding, thermo-forming, or deep drawing.

17. The acoustic element according to claim 12, wherein the chamber portion of the three-dimensional canister is partially filled with the acoustic adsorber material.

18. The acoustic element according to claim 12, wherein the chamber portion of the three-dimensional canister is substantially filled with the acoustic adsorber material.

19. The acoustic element according to claim 12, wherein the sound transmissibility of the chamber portion is less than the sound transmissibility of the acoustically porous wall portion.

20. The acoustic element according to claim 12, wherein the acoustically porous wall portion has low acoustic resistance and comprises one or more of a filter material, a fleece material, a foam material, a sieve material, a mesh material, or a cloth fabric formed from fibers.

21. The acoustic element according to claim 20, wherein openings in the material of the acoustically porous wall portion are adapted to be less than the particle size of the acoustic adsorber material.

22. The acoustic element according to claim 12, wherein the shape of the three-dimensional canister provides a predetermined spatial distribution of the acoustic adsorber material within the back volume of the acoustic device.

23. The acoustic element according to claim 12, wherein the external surfaces of at least a portion of the acoustically porous portion of the three-dimensional container are configured to substantially conform to the internal surfaces of a predetermined portion of the back volume of the acoustic device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a cross-sectional view of a loudspeaker device in accordance with embodiments of the herein disclosed subject-matter.

(2) FIG. 2 shows a side view of an acoustic element in accordance with embodiments of the herein disclosed subject-matter.

(3) FIG. 3 shows a top view of the acoustic element 102 viewed from line III-III in FIG. 2.

(4) FIG. 4 shows a further acoustic element 102 in cross-sectional view in accordance with embodiments of the herein disclosed subject-matter.

(5) FIG. 5 shows a top view of an acoustic element 102 in accordance with embodiments of the herein disclosed subject-matter.

(6) FIG. 6 shows a further acoustic element 102 in accordance with embodiments of the herein disclosed subject-matter.

DETAILED DESCRIPTION

(7) The illustration in the drawings is schematic. It is noted that in different figures, similar or identical elements are provided with the same reference signs or with reference signs which are different from the corresponding reference signs only within the first digit or an appended character.

(8) Acoustically active materials, i.e. acoustic volume increasing materials, can be used in the back volume of a loudspeaker device to improve the sound, e.g. the wideband performance, and/or to increase the acoustic volume of the loudspeaker and save space. Such acoustically active materials include zeolite materials or zeolite-based materials. Such electrically isolating materials are superior to conventional acoustically active materials like activated carbon, because they are electrically non-conductive and hence do not influence an antenna, a battery effect or bear the risk of short circuits. Furthermore, packaging of these materials is much easier than in case of activated carbon woven fabrics.

(9) A problem may arise in insertion of the materials consisting or at least comprising loose particles, in the back volume of the loudspeaker device. Furthermore, the back volume of a miniature loudspeaker, such as a loudspeaker device placed in mobile phones, headsets, etc., is often built up by the surrounding area of the loudspeaker and is not well-defined. A direct insertion of the acoustically active materials into the surrounding area is practically difficult. Furthermore, the acoustically active materials can enter into the different components of the device having included the loudspeaker device and also in the loudspeaker itself and can therefore damage the device or the loudspeaker.

(10) Embodiments of the herein disclosed subject-matter overcome these disadvantages by enclosing acoustically active materials in a container. This simplifies mounting and provides additionally a protection of the loudspeaker and the remaining device.

(11) FIG. 1 shows a loudspeaker device in accordance with embodiments of the herein disclosed subject-matter. The loudspeaker device 100 comprises an acoustic element 102 in accordance with embodiments of the herein disclosed subject-matter. The acoustic element 102 includes a container 104 and an acoustic volume increasing material 106 in the form of loose particles in the container 104. It should be noted that only a few particles 106 are shown in FIG. 1 and that usually the container will be filled to a large extent or may be completely filled with the acoustic volume increasing material. The loudspeaker device 100 further comprises a housing including a base plate 108 and a wall structure 110. The wall structure 110 separates a loudspeaker receptacle 112 which has mounted thereon a loudspeaker 114, and a microphone receptacle 116 which has mounted thereon a microphone 118.

(12) The wall structure 110 further defines a back volume 120 in which the acoustic element 102 is located. In an embodiment, the size and the shape of the acoustic element 102 matches the size and the shape of the back volume, thereby providing for a maximum filling level of the back volume.

(13) It should however be noted, that the configuration shown in FIG. 1 is only exemplary and that other loudspeaker devices may not include a microphone receptacle or a microphone. Further, the back volume is, in another embodiment, not defined by a wall structure but only by surrounding components which surround the loudspeaker 114 in a device in which the loudspeaker is mounted. Such a device may be for example a mobile phone, a headset, etc. In such applications, the loudspeaker device may be a miniature loudspeaker device.

(14) The acoustic element 102 may be configured in accordance with one or more embodiments disclosed herein.

(15) FIG. 2 shows a side view of an acoustic element in accordance with embodiments of the herein disclosed subject-matter. The acoustic element 102 is made of a container 104 which has a cup-shaped second wall portion 122 and, as a cover of the second wall portion 122, a first wall portion 124 which has a high sound transmissibility. Hence, while in an embodiment the cup-shaped second wall portion 122 serves as a receptacle for receiving the acoustic volume increasing material (not shown in FIG. 2), the first wall portion 124 serves to couple sound from the loudspeaker into the container and into the acoustic volume increasing material. For example, in an embodiment the second wall portion 122 is made of a plastic whereas the first wall portion 124 is made of for example a fiber material, such as a sound transparent fleece or a foam being capable of passing the sound through the first wall portion.

(16) According to an embodiment, cup-shaped second wall portion 122 is a rigid structure. Such a rigid structure guaranties a good mounting ability and robustness.

(17) FIG. 3 shows a top view of the acoustic element 102 viewed from line III-III in FIG. 2. The side view of FIG. 2 in turn is obtained when viewing the acoustic element 102 from line II-II in FIG. 3.

(18) As can be seen from FIG. 3, the container 104 may have a predetermined three-dimensional shape. According to an embodiment, a three dimensional (3D) container (bag) having on all sides the sound transparent material is provided. The shape of such a 3D geometry means that a more complex geometry is evident not only in the xy direction (drawing plane in FIG. 3) but also in the z direction. The 3D container has the advantage that it can fill a complex shaped back cavity more efficiently than the simple rectangular bags, which are however also in the scope of exemplary embodiments of the herein disclosed subject matter.

(19) In an alternative embodiment, the container 104 or at least a container wall is made from a single type of material. For example, the shape shown in FIG. 2 and FIG. 3 may also be obtained by only using a fiber material of suitable shape.

(20) FIG. 4 shows a further acoustic element 102 in cross-sectional view in accordance with embodiments of the herein disclosed subject-matter. The acoustic element 102 in FIG. 4 is made of a single type of wall material. In particular, the container 104 of the acoustic element 102 in FIG. 4 is made of two wall portions 124, 122 which are both made of a wall material of the same type. To obtain the container 104, an upper wall portion 124 and a lower wall portion 122 are attached together at overlapping edge sections 126 of the wall portions 124, 122. The wall portions 124, 122 enclose a cavity 105 that is filled with the acoustic volume increasing material (not shown in FIG. 4).

(21) FIG. 5 shows a top view of an acoustic element 102 in accordance with embodiments of the herein disclosed subject-matter. As shown in FIG. 5, a container comprising container walls being formed of a single type of material may also be formed in more complicated shapes as shown in FIG. 5. Again an upper wall portion 124 and a lower wall portion 122 are attached to each other at an edge portion 126. However, the shape shown in FIG. 5 may be realized by any other suitable configuration of the wall portions and attachment methods.

(22) According to an embodiment, the upper wall portion 124 and the lower wall portion 122 as described herein may be attached to each other by gluing, crimping, stamping, embossing, heat sealing or the like.

(23) FIG. 6 shows a further acoustic element 102 in accordance with embodiments of the herein disclosed subject-matter. The container 104 of the acoustic element 102 shown in FIG. 6 is made of a single sheet 127 of wall material. The single sheet 127 of wall material is folded to form the container 104. Hence, there is a vertical overlapping region 128 and two edge portions 126 where an upper wall portion overlaps a lower wall portion of the single sheet 127 of wall material.

(24) The edge portions 126 of the containers 104 shown in FIG. 4, FIG. 5 and FIG. 6 may have formed the edge portions 126 in the form of seams. The overlapping region 128 is preferably positioned at a side opposite a first side which faces the loudspeaker, since the overlapping region may have a reduced sound transparency.

(25) Generally in accordance with embodiments of the herein disclosed subject matter, a single wall portion, two or more wall portions, or all wall portions of the container may be of sound transparent material.

(26) It should be noted that any entity disclosed herein (e.g. the acoustic element, the container, the loudspeaker device, etc.) are not limited to a dedicated entity as described in some embodiments. Rather, the herein disclosed subject matter may be implemented in various ways and with arbitrary granularity on device level while still providing the desired functionality. Further, it should be noted that according to embodiments a separate entity may be provided for each of the functions disclosed herein. According to other embodiments, an entity is configured for providing two or more functions as disclosed herein.

(27) It should be noted that the term comprising does not exclude other elements or steps and the a or an does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

(28) In order to recapitulate the above described embodiments of the present invention one can state:

(29) There is provided an acoustic element for placement in a sound path of a loudspeaker device, the acoustic element comprising a container and an acoustic volume increasing material located in the container. In an embodiment, the container comprises wall portions with different physical characteristics. In other embodiments, the walls of the container are made of the same material.

LIST OF REFERENCE SIGNS

(30) 100 loudspeaker device 102 acoustic element 104 container 105 cavity 106 acoustic volume increasing material 108 base plate 110 wall structure 112 loudspeaker receptacle 114 loudspeaker 116 microphone receptacle 118 microphone 120 back volume 122 second wall portion 124 first wall portion 126 edge portion 127 single sheet 128 overlapping region