Balanced armature receiver having a diaphragm element with integrated sealing rim

Abstract

The invention relates to a balanced armature, BA, receiver, a hearing device comprising the BA receiver and a method for producing the BA receiver. The BA receiver comprises a magnet assembly, an electromagnetic coil, an armature and a diaphragm element. The magnet assembly generates a magnetic field in an air gap. The coil comprises a coil tunnel. The armature extends through the air gap and the coil tunnel. The diaphragm element comprises a membrane portion and a sealing rim that are formed as an integral part. The membrane portion is directly attached to the armature for moving the membrane portion with the armature. The sealing rim extends along the perimeter of the membrane portion and is arranged to seal a front volume of the receiver from a back volume of the receiver.

Description

[0001] BALANCED ARMATURE RECEIVER HAVING A DIAPHRAGM ELEMENT WITH INTEGRATED

[0002] SEALING RIM

[0003] Field of the invention

[0004] The present invention relates to a balanced armature receiver and a method for production of said balanced armature receiver. The invention further relates to a hearing device comprising said balanced armature receiver.

[0005] Background of the invention

[0006] A balanced armature receiver ("BA receiver") is a sound generator, that is typically used in hearing devices, such as hearing aids. BA receivers comprises an armature, a magnet assembly and an electromagnetic coil. The armature has a movable end and a fixed end. The electromagnetic coil is coupled to the armature and induces a changing magnetic field when an electric input signal is provided. The magnet assembly generate a static magnetic field. The armature extends through the static magnetic field of the magnet assembly. The armature is magnetically permeable and the changing magnetic field of the coil magnetizes the armature, which causes the armature to be attracted to or repelled by the magnet assembly. The electric input signal thus controls the movement of the armature relative to the magnet assembly. The armature moves a diaphragm to produce sound. This type of receiver is also referred to as a moving armature receiver.

[0007] EP 1 962 551 A2 describes a movable armature receiver wherein the diaphragm is attached to the armature and extends between two permanent magnets. The diaphragm has resilient side portions that engage a brass sealing member which seals a space above the diaphragm from a space below the diaphragm.

[0008] Description of the invention

[0009] A drawback of conventional BA receivers is that their production requires many production steps, some of which include manually pick and placing the components of the receiver.

[0010] An object of the invention is to overcome said drawbacks, or at least provide an alternative BA receiver. In particular, the invention aims to provide a movable armature receiver that can be produced more easily.

[0011] This aim is achieved by the balanced armature receiver according to claim 1. The BA receiver comprises a magnet assembly, an electromagnetic coil, an armature and a diaphragm element. The magnet assembly is arranged to generate a magnetic field in an air gap. The electromagnetic coil comprises a coil tunnel. The armature extends through the air gap and the coil tunnel. The diaphragm element comprises a membrane portion and a sealing rim. The membrane portion and sealing rim are formed as an integral part. The membrane portion is directly attached to the armature for moving the membrane portion with the armature. The sealing rim extends along the perimeter of the membrane portion. The sealing rim is arranged to seal a front volume of the receiver from a back volume of the receiver.

[0012] By providing the membrane portion and a sealing rim as an integral part, the production of the BA receiver is simplified. In particular, less parts are needed to assemble the receiver, which simplifies production, e.g. as compared to the receiver of EP 1 962 551 A2.

[0013] The sealing rim extends along the perimeter of the membrane portion. In other words, the sealing rim forms a circumferential wall around the membrane portion.

[0014] The membrane portion is directly attached to the armature, i.e. the membrane portion is in direct contact with and affixed to the armature. For example, the membrane portion is attached to the armature using an adhesive.

[0015] Preferably, the magnet assembly includes one or more permanent magnets, such that in use the magnet assembly generates a static magnetic field without requiring any power input.

[0016] Preferably, the membrane portion of the diaphragm element is attached to the armature using an adhesive, for example silicone glue or epoxy.

[0017] Preferred embodiments are defined in the dependent claims and in the following paragraphs.

[0018] In an embodiment, the magnet assembly comprises a magnet arranged at a distance from the electromagnetic coil, and the diaphragm element encloses said magnet of the magnet assembly.

[0019] In case the magnet assembly comprises more than one magnet, at least one of them is arranged at a distance from the coil and enclosed by the diaphragm element.

[0020] Preferably, the sealing rim extends between said magnet and the electromagnetic coil.

[0021] In an embodiment, the membrane portion comprises a substantially flat section that is attached to the armature and a slanted or curved section that connects the substantially flat section to the sealing rim. The slanted or curved section prevents compression of the sealing rim due to movement of the armature, thereby avoiding damaging the diaphragm element.

[0022] Particularly, the slanted or curved section ensures that a gap exists between the sealing rim and the armature. The gap ensures that the armature does not, or at least not substantially, compress the sealing rim. In other words, the slanted or curved section of the membrane portion absorbs movements of the armature, to prevent compression of the sealing rim.

[0023] Whereas the substantially flat section of the membrane portion is attached to the armature, e.g. using an adhesive, the slanted or curved section is preferably not attached to the armature (i.e. not directly attached to the armature, but rather connected to the armature via the flat section). In some embodiments, the armature overlaps part of the sealing rim. For example, the armature extends above or beneath part of the sealing rim. Without the presence of the slanted or curved section of the membrane, movement of the armature would cause compression of the sealing rim in those overlapping areas. Thus preferably, a slanted or curved section adjoins the sealing rim at least on those locations where the armature overlaps the sealing rim. In locations where the armature does not overlap the sealing rim, the diaphragm element can optionally also include a slanted or curved section. Alternatively, no slanted or curved section is provided in those non-overlapping locations (e.g. the sealing rim and the membrane portion meet at substantially 90 degrees).

[0024] In a further embodiment, the slanted or curved section follows a monotonic path from the substantially flat section towards the sealing rim. For example, if the substantially flat section is seen as a top part of the diaphragm element, the slanted or curved section slopes monotonically down towards the sealing rim. Similarly, if the substantially flat section is seen as a bottom part of the diaphragm element, the slanted or curved section slopes monotonically up towards the sealing rim.

[0025] In an example, the monotonic path described by the slanted or curved section comprises a continuous (smooth) curve. In another example, the monotonic path described by the slanted or curved section is discontinuous (not smooth), e.g. the slanted or curved section comprises one or more straight sections provided at an angle to both the substantially flat section and the sealing rim.

[0026] For example, the sealing rim extends at substantially 90 degrees with respect to the substantially flat section of the membrane portion. The slanted or curved section of the membrane portion joins the sealing rim to the flat section of the membrane portion, where the slanted or curved section describes a monotonic path from the substantially flat section towards the sealing rim.

[0027] In an embodiment, the connection between the slanted or curved section and the substantially flat section is discontinuous, such that an edge is defined between the slanted or curved section and the substantially flat section. In other words, the substantially flat section does not transition smoothly into the curved or slanted section, but rather exhibits an abrupt change.

[0028] This is advantageous when the substantially flat section is attached to the armature using an adhesive, glue or other liquid. The edge prevents the adhesive (or glue or other liquid) from flowing to the curved section, which would happen in case of a smooth transition.

[0029] In an embodiment wherein the membrane portion comprises a curved section, the curved section curves inwards with respect to a volume enclosed by the sealing rim. This is particularly suitable for preventing compression of the membrane. For example, the curved section curves into the front volume that is enclosed by the sealing rim. For example, the curved section has a cross-section describing a circular arc, for example, the cross-section of the curved section describes a quarter circle.

[0030] In an embodiment, the armature has a fixed end and a movable end. The armature extends from the fixed end through the air gap and the coil tunnel to the movable end. A first part of the membrane portion extends beyond the movable end of the armature, as seen in the direction from the fixed end towards the movable end.

[0031] In other words, the armature does not overlap said first part of the membrane portion. Arranging the diaphragm element in this manner is another way of preventing compression of the sealing rim, particularly compression of the sealing rim along the perimeter of said first part of the membrane. Thus, damage to the diaphragm element is prevented.

[0032] In a further embodiment, a second part of the membrane portion, opposite to the first part, comprises the slanted or curved section.

[0033] Particularly, the second part of the membrane portion does not extend beyond the movable end of the armature, as seen in the direction from the fixed end towards the movable end.

[0034] In other words, where the armature overlaps the sealing rim, the membrane portion is provided with a slanted or curved section.

[0035] Other parts may optionally also comprise a slanted or curved section, i.e. the membrane portion may comprise more than one slanted or curved section connecting the substantially flat section of the membrane portion to the sealing rim.

[0036] In an embodiment, the distance between the armature and the sealing rim is substantially constant near the movable end of the armature. By keeping said distance constant, the frequency response of the BA receiver is improved.

[0037] A first end of the sealing rim extends beyond the movable end of the armature, as seen in the direction from the fixed end towards the movable end. A second end of the sealing rim, opposite to the first end, overlaps the armature (e.g. extends above or below the armature). At least near the first end, the distance between the armature and the sealing rim is substantially constant.

[0038] In an exemplary embodiment, the sealing rim comprises rounded corners near the movable end of the armature, to maintain said substantially constant distance.

[0039] In an embodiment, the receiver comprises a housing. The magnet assembly, the electromagnetic coil and the diaphragm element are arranged in the housing. The sealing rim is attached to the housing.

[0040] Preferably, the sealing rim is sealed against the housing, such that the sealing rim encloses a front volume of the receiver that is sealed by the sealing rim from a back volume of the receiver. The magnet is preferably provided in said front volume. Preferably, the sealing rim is sealed against a planar inner surface of the housing, the planar inner surface extending parallel to the armature. In such a case, a space is defined between the planar inner surface of the housing and the diaphragm element. When the diaphragm element encloses a magnet of the magnet assembly as described above, said magnet is preferably positioned in said space between the planar inner surface and the diaphragm element.

[0041] For example, the sealing rim is attached to the housing using an adhesive, such as silicone glue or epoxy. For example, the sealing rim is attached to an inner surface of the housing.

[0042] In an embodiment, the sealing rim comprises an opening for letting out sound. In a further embodiment, the housing comprises a sound outlet aligned with the opening in the sealing rim.

[0043] For example, the opening for letting out sound spans 20% - 60% of the height of the sealing rim, preferably 30 - 50%.

[0044] In an embodiment the membrane portion and the sealing rim are formed of the same material. This further simplifies production. In contrast, in EP 1 962 551 A2, a brass sealing member is provided and a separate diaphragm made of a sheet of PET.

[0045] Providing the membrane portion and the sealing rim from the same material is particularly advantageous in combination with the above-described features for preventing compression of the sealing rim. Preferably, the diaphragm element consists of a single material.

[0046] In an embodiment, the membrane portion and the sealing rim both comprise silicone. Preferably, the diaphragm element consist of silicone.

[0047] Preferably, the silicone membrane portion is attached to the armature using glue. Preferably, the silicone sealing rim is attached to the housing using glue.

[0048] In another embodiment, the membrane portion and the sealing rim comprise polyurethane (PU).

[0049] In an embodiment, the membrane portion of the diaphragm element has a thickness of 5 - 100 micron, preferably of 5-75 micron, more preferably of 5-50 micron.

[0050] The invention further relates to a hearing device comprising the receiver according to any of the embodiments described herein. Preferably, the hearing device is an in-ear device. Preferably, the hearing device is a hearing aid, more preferably an in-ear hearing aid. Other examples of hearing devices include headphones, particularly in-ear headphones (e.g. earbuds). The invention further relates to a method for producing such a receiver.

[0051] In particular, the method comprises a step of providing a magnet assembly for generating a magnetic field in an air gap. The method further comprises a step of providing an electromagnetic coil comprising a coil tunnel. The method further comprises a step of providing an armature such that it extends through the air gap and the coil tunnel. The method further comprises a step of providing a diaphragm element comprising a membrane portion and a sealing rim. The membrane portion and the sealing rim are formed as an integral part. The sealing rim extends along the perimeter of the membrane portion. The method further comprises a step of attaching the membrane portion of the diaphragm element directly to the armature for moving the membrane portion with the armature. The sealing rim seals a front volume of the receiver from a back volume of the receiver

[0052] The same technical effects as described above in relation to the BA receiver apply to method of the invention. Moreover, any features of the BA receiver described above can similarly be applied in the method, and vice versa.

[0053] Brief description of the drawings

[0054] In the following, example embodiments will be described with reference to the drawings, wherein:

[0055] Figures 1-4 illustrate a BA receiver according to a first embodiment of the invention;

[0056] Figure 5 shows the diaphragm element of the BA receiver of Figures 1-4;

[0057] Figure 6 and 7 illustrate a BA receiver according to a second embodiment of the invention;

[0058] Figure 8 shows the diaphragm of the BA receiver of Figures 6 and 7;

[0059] Figure 9 shows a variant of the diaphragm element of Figure 5; and

[0060] Figure 10 shows a schematic bottom view of a further variant of the diaphragm element.

[0061] Detailed description of the drawings

[0062] Figures 1-4 illustrate a BA receiver 2 according to a first embodiment. Figure 1 shows a bottom part of the receiver 2. The receiver 2 comprises a bottom housing part 4a and a middle housing part 4b. The middle housing part 4b rests on bottom housing part 4a. The middle housing part 4b comprises side wall portions 6 that form part of the side walls of the receiver's housing. The middle housing part 4b further comprises an armature 8. The armature 8 is magnetically permeable, and comprises metal. The armature has a movable end 8a and a fixed end 8b. The receiver 2 further comprises an electromagnetic coil comprising a coil tunnel 10. The armature 8 extends through the coil tunnel 10 and through an air gap between two permanent magnets 12, 14 (figure 4).

[0063] In the example of figures 1-4, the side wall portions 6 and armature 8 are formed as a single piece of the same material. The invention is not limited thereto, and the armature 8 may alternatively be provided as a component separate from the side wall portions 6. Moreover, the side wall portions 6 may be omitted, and the armature 8 may be attached to the housing in a different manner, e.g. attached to a top or bottom wall of the housing. The movable end 8a of armature 8 is movable by providing a drive signal to the coil 10. The drive signal induces a changing magnetic field in the coil 10. The magnetic field extends through the magnetic permeable armature 8, and causes the armature 8 to move towards and away from permanents magnets 12, 14.

[0064] The BA receiver 2 further comprises a diaphragm element 16 (Figure 2). The diaphragm element 16 is arranged between the magnets 12, 14. In this example, the diaphragm is made of silicone. The diaphragm 16 is attached to the armature 8 by a glue.

[0065] The silicone diaphragm 16 is shown in more detail in Figure 5. The diaphragm comprises a membrane portion 18 and, along the perimeter thereof, a sealing rim 20. The membrane portion 18 and sealing rim 20 are integrally formed as a single silicone part.

[0066] The membrane portion 18 and the sealing rim 20 define an inner space in which magnet 14 is accommodated. An upper part 4c of the housing (Figure 3) is placed on top of the middle housing part 4b, and the sealing rim 20 is attached to the upper housing part 4c, using an adhesive (in this example silicone glue). Specifically, the sealing rim is attached to a planar inner surface of the upper housing part 4c. The diaphragm 16 thus seals a front volume of the receiver, in which the magnet 14 is located, from a back volume of the receiver. This is shown in more detail in the cross-section of Figure 4.

[0067] Referring again to figure 5, the membrane portion 18 comprises a substantially flat section 18a and a slanted section 18b. The slanted section 18b joins the substantially flat section 18a to the sealing rim 20. As can seen clearly in the cross-section of Figure 4, the slanted section 18b follows a monotonic path. The slanted section joins the flat section 18a at an angle, such that an edge 18c is formed.

[0068] The membrane portion 18 is relatively thin as compared to the sealing rim 20. For example, the membrane portion 18 has a thickness of 5-50 micron. In the example, the flat section 18a and the slanted section 18b have the substantially the same thickness, whereas the sealing rim is thicker, preferably at least 100 micron, more preferably at least 500 micron, e.g. at least 1000 micron.

[0069] In figures 1-3, a first end A of the diaphragm 16 extends above armature 8, whereas a second, opposing end B of the diaphragm 16 does not extend above the movable end 8a of the armature. Because of the distance between the movable end 8a and the second end B of the diaphragm 16, the sealing rim 20 near the second end B of the diaphragm 16 will experience no or little compression when the armature 8 moves. To also provide a distance between the sealing rim 20 and the armature 8 near the first end A, the slanted section 18b is provided. Movement of the armature 8 is absorbed by the slanted section 18b, rather than said movement acting directly on the portion of the sealing rim 20 near first end A.

[0070] In this example, the slanted section 18b is provided adjacent to the first end A of the diaphragm 16, whereas the membrane portion 18 does not comprises a slanted section adjacent to the second end B. Alternatively, the membrane portion 18 may comprise a slanted section at second end B as well (cf. the alternative embodiment of Figures 6 and 7).

[0071] Referring to figures 2 and 5, the diaphragm element 16 comprises an opening for letting out sound, in the form of an opening 24 in sealing rim 20. The opening 24 is provided near the second end B of the diaphragm 16. The sealing rim 20 generally comprises a wall of uniform height, except for a portion near the second end B where the wall has a reduced height to form the opening 24. In other words, the opening for letting out sound may be formed as a recess or notch in a wall of the sealing rim.

[0072] The upper housing part 4c comprises a sound outlet 26, in the form of an opening in the housing part 4c. Sound outlet 26 of the housing is aligned with opening 24 of the diaphragm 16, for allowing sound to pass through both openings 24, 26.

[0073] Next, a method for producing receiver 2 is described. Two magnets 12, 14, a coil 10, and an armature 8 are provided. In addition a silicon diaphragm 16 element is produced using injection molding. The lower magnet 12 is attached to the lower housing part 4a. The armature 8 is fed through coil 10. The combined armature 8 and coil 10 are placed in the lower housing part 4a. In this example, the armature 8 is formed as an integral part with side wall portions 6. The side wall portions 6 are positioned on top of the wall portions of lower housing part 4a. The silicone diaphragm element 16 is attached to the top surface of the armature 8 using glue. Glue is also applied to the top of the sealing rim 20, after which an upper part 4c of the housing is placed, i.e. on top of the middle housing part 4b.

[0074] In this example, a glue is applied to the top surface of magnet 14 prior to placing the upper part 4c of the housing, to attach the magnet 14 to the housing. Alternatively, the upper part 4c may comprise a structure for holding the magnet 14 in place, for example in the form of ribs protruding from the housing part for clamping the magnet between the ribs. In another alternative, the magnet is glued or otherwise attached to the housing part 4c prior to placing the housing part 4c on the middle housing portion 4b.

[0075] Figures 6 and 7 show a receiver 2' according to a second embodiment. Many elements of the receiver 2' are the same as in the first embodiment of figures 1-4. The same reference numerals are used to indicate the same elements. Elements that differ from the first embodiment are indicated using a prime (').

[0076] Notably, the receiver 2' of figures 6 and 7 differs from receiver 2 of figures 1-4 in that it includes a different diaphragm element 16'. In this example, the diaphragm element 16' is made of polyurethane ("PU"). However, the invention is not limited to PU, and other materials (e.g. other polymers) may be used, such as polyethylene terephthalate ("PET").

[0077] Diaphragm element 16' comprises a membrane portion 18' and a sealing rim 20' (figure 8). In this example, the sealing rim 20' is formed as a flange, comprising a substantially flat surface for attaching to the housing (i.e. upper housing portion 4c). The membrane portion 18' comprises a substantially flat section 18a' for attaching to the armature 8. Adjoining the flat section 18a' is a curved section 18b' that connects the flat section 18a' to the sealing rim 20'.

[0078] In the example of Figures 6-8, the sealing rim 20' and membrane portion 18' have the same thickness. The thickness is for example 5-100 micron. Alternatively, the sealing rim has a greater thickness than the membrane portion 18'.

[0079] Production of the receiver 2' is similar to production of receiver 2 described above, except that diaphragm element 16' is produced differently. Although it is possible according to the invention to produce diaphragm element 16' by injection molding, it is currently preferred to produce diaphragm element 16' by pressing a PU foil into the form of the diaphragm element. Form pressing preferably comprises heating the PU foil. Alternatively, other polymer foils are used for producing diaphragm element 16', such as a PET foil.

[0080] Figure 9 shows a variant of the diaphragm element 16 of figure 5. The diaphragm element 16" of figure 9 is also made of a silicone. The diaphragm element 16" includes a membrane portion 18a", 18b" and a sealing rim 20". The membrane portion comprises a substantially flat section 18a" that joins a curved section 18b". The curved section 18b" is concave, in the sense that it curves into the volume enclosed by sealing rim 20".

[0081] An edge 18c" is formed where the curved section 18b" joins the flat section 18a". This curvature reduces tension in section 18b" when the membrane portion 18a" is vibrating with the armature 8, and thereby improves the frequency response of the receiver.

[0082] Figure 10 schematically shows a further variant of a diaphragm element, in bottom view. As before, the diaphragm element 16'" includes a membrane portion and a sealing rim. The figure illustrates that, near the movable end of armature 8 (side B), the sealing rim 20'" of diaphragm element 16'" is at a constant distance d from the armature 8. Preferably, a constant distance between the sealing rim 20'" and the armature 8 is maintained over most of the length of the sealing rim, except near the end of the sealing rim 20'" that opposes the free end (side A), i.e. the end that preferably includes a slanted or curved section.

[0083] In the example of figure 10, armature 8 is substantially rectangular. In this example, the sealing rim 20'" has rounded corners, to maintain a constant distance to the corners at the free end of the rectangular armature 8.

[0084] Preferably, the features of Figure 9 and 10 are combined, e.g. the diaphragm 16" of Figure 9 is provided at end B with the rounded corners of Figure 10.

[0085] Embodiments

[0086] 1. A balanced armature receiver comprising:

[0087] - a magnet assembly generating a magnetic field in an air gap;

[0088] - an electromagnetic coil comprising a coil tunnel;

[0089] - an armature extending through the air gap and the coil tunnel; and - a diaphragm element comprising a membrane portion and a sealing rim that are formed as an integral part, wherein the membrane portion is connected to, and preferably directly attached to, the armature for moving the membrane portion with the armature, and wherein the sealing rim extends along the perimeter of the membrane portion and is arranged to seal a front volume of the receiver from a back volume of the receiver.

[0090] 2. The balanced armature receiver of embodiment 1, wherein the magnet assembly comprises a magnet arranged at a distance from the electromagnetic coil, and the diaphragm element encloses said magnet of the magnet assembly.

[0091] 3. The balanced armature receiver of embodiment 1 or embodiment 2, wherein the membrane portion comprises a substantially flat section that is connected to, and preferably attached to, the armature and a slanted or curved section that connects the substantially flat section to the sealing rim.

[0092] 4. The balanced armature receiver of embodiment 3, wherein the slanted or curved section follows a monotonic path from the flat section towards the sealing rim.

[0093] 5. The balanced armature receiver of embodiment 3 or 4, wherein the connection between the slanted or curved section and the substantially flat section is discontinuous, such that an edge is defined between the slanted or curved section and the substantially flat section.

[0094] 6. The balanced armature receiver of embodiment 3, 4 or 5, wherein the curved section curves inwards with respect to a volume enclosed by the sealing rim.

[0095] 7. The balanced armature receiver of any one or more of the embodiments 1-6, wherein the armature has a fixed end and a movable end, the armature extending from the fixed end through the coil tunnel and air gap to the movable end, wherein a first part of the membrane portion extends beyond the movable end of the armature, as seen in the direction from the fixed end towards the movable end.

[0096] 8. The balanced armature receiver of embodiment 7 in combination with any of the embodiments 3-6, wherein a second part of the membrane portion, opposite to the first part, comprises the slanted or curved section.

[0097] 9. The balanced armature receiver of any one or more of the preceding embodiments, wherein the distance between the armature and the sealing rim is substantially constant near the movable end of the armature.

[0098] 10. The balanced armature receiver of embodiment 9, wherein the sealing rim comprises rounded corners near the movable end of the armature to maintain the substantially constant distance between the armature and the sealing rim.

[0099] 11. The balanced armature receiver of any one or more of the embodiments 1-10, further comprising a housing in which the magnet assembly, the electromagnetic coil and the diaphragm element are arranged, wherein the sealing rim is attached to the housing. 12. The balanced armature receiver of any one or more of the embodiments 1-11, wherein the sealing rim comprises an opening for letting out sound.

[0100] 13. The balanced armature receiver of the combination of embodiments 11 and 12, wherein the housing comprises a sound outlet aligned with the opening in the sealing rim.

[0101] 14. The balanced armature receiver according to any one or more of the embodiments 11-13, wherein the sealing rim is sealed against a planar inner surface of the housing extending parallel to the armature.

[0102] 15. The balanced armature receiver of any one or more of the embodiments 1-14, wherein the membrane portion and the sealing rim are formed of the same material.

[0103] 16. The balanced armature receiver of embodiment 15, wherein the membrane portion and the sealing rim comprise silicone.

[0104] 17. The balanced armature receiver of embodiment 15, wherein the membrane portion and the sealing rim comprise polyurethane.

[0105] 18. The balanced armature receiver of any one or more of the embodiments 1-17, wherein the membrane portion of the diaphragm element has a thickness of 5 - 50 micron.

[0106] 19. A hearing device comprising the receiver according to any one or more of the preceding embodiments.

[0107] 20. A method for producing a balanced armature receiver, the method comprising:

[0108] - providing a magnet assembly for generating a magnetic field in an air gap;

[0109] - providing an electromagnetic coil comprising a coil tunnel;

[0110] - providing an armature such that it extends through the air gap and the coil tunnel;

[0111] - providing a diaphragm element comprising a membrane portion and a sealing rim that are formed as an integral part, wherein the sealing rim extends along the perimeter of the membrane portion;

[0112] - connecting the membrane portion of the diaphragm element to the armature, preferably directly attaching thereto, for moving the membrane portion with the armature, wherein the sealing rim seals a front volume of the receiver from a back volume of the receiver

Claims

CLAIMS1. A balanced armature receiver comprising:- a magnet assembly generating a magnetic field in an air gap;- an electromagnetic coil comprising a coil tunnel;- an armature extending through the air gap and the coil tunnel; and- a diaphragm element comprising a membrane portion and a sealing rim that are formed as an integral part, wherein the membrane portion is directly attached to the armature for moving the membrane portion with the armature, and wherein the sealing rim extends along the perimeter of the membrane portion and is arranged to seal a front volume of the receiver from a back volume of the receiver.

2. The balanced armature receiver of claim 1, wherein the magnet assembly comprises a magnet arranged at a distance from the electromagnetic coil, and the diaphragm element encloses said magnet of the magnet assembly.

3. The balanced armature receiver of claim 1 or claim 2, wherein the membrane portion comprises a substantially flat section that is attached to the armature and a slanted or curved section that connects the substantially flat section to the sealing rim.

4. The balanced armature receiver of claim 3, wherein the slanted or curved section follows a monotonic path from the flat section towards the sealing rim.

5. The balanced armature receiver of claim 3 or 4, wherein the connection between the slanted or curved section and the substantially flat section is discontinuous, such that an edge is defined between the slanted or curved section and the substantially flat section.

6. The balanced armature receiver of claim 3, 4 or 5, wherein the curved section curves inwards with respect to a volume enclosed by the sealing rim.

7. The balanced armature receiver of any one or more of the claims 1-6, wherein the armature has a fixed end and a movable end, the armature extending from the fixed end through the coil tunnel and air gap to the movable end, wherein a first part of the membraneportion extends beyond the movable end of the armature, as seen in the direction from the fixed end towards the movable end.

8. The balanced armature receiver of claim 7 in combination with any of the claims 3-6, wherein a second part of the membrane portion, opposite to the first part, comprises the slanted or curved section.

9. The balanced armature receiver of any one or more of the preceding claims, wherein the distance between the armature and the sealing rim is substantially constant near the movable end of the armature.

10. The balanced armature receiver of claim 9, wherein the sealing rim comprises rounded corners near the movable end of the armature to maintain the substantially constant distance between the armature and the sealing rim.

11. The balanced armature receiver of any one or more of the claims 1-10, further comprising a housing in which the magnet assembly, the electromagnetic coil and the diaphragm element are arranged, wherein the sealing rim is attached to the housing.

12. The balanced armature receiver of any one or more of the claims 1-11, wherein the sealing rim comprises an opening for letting out sound.

13. The balanced armature receiver of the combination of claims 11 and 12, wherein the housing comprises a sound outlet aligned with the opening in the sealing rim.

14. The balanced armature receiver according to any one or more of the claims 11-13, wherein the sealing rim is sealed against a planar inner surface of the housing extending parallel to the armature.

15. The balanced armature receiver of any one or more of the claims 1-14, wherein the membrane portion and the sealing rim are formed of the same material.

16. The balanced armature receiver of claim 15, wherein the membrane portion and the sealing rim comprise silicone.

17. The balanced armature receiver of claim 15, wherein the membrane portion and the sealing rim comprise polyurethane.

18. The balanced armature receiver of any one or more of the claims 1-17, wherein the membrane portion of the diaphragm element has a thickness of 5 - 50 micron.

19. A hearing device comprising the receiver according to any one or more of the preceding claims.

20. A method for producing a balanced armature receiver, the method comprising:- providing a magnet assembly for generating a magnetic field in an air gap;- providing an electromagnetic coil comprising a coil tunnel;- providing an armature such that it extends through the air gap and the coil tunnel;- providing a diaphragm element comprising a membrane portion and a sealing rim that are formed as an integral part, wherein the sealing rim extends along the perimeter of the membrane portion;- attaching the membrane portion of the diaphragm element directly to the armature for moving the membrane portion with the armature, wherein the sealing rim seals a front volume of the receiver from a back volume of the receiver.

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