HEARING DEVICE

Abstract

A hearing device has a motherboard and a receiver module. The receiver module is configured for wireless charging of a battery and, for that purpose, has a coil wound around an axial direction. The motherboard has a top section that extends perpendicular to the axial direction and in a radial direction. The top section of the motherboard and the receiver module are stacked in the axial direction.

Claims

1. A hearing device, comprising: a receiver module configured for wireless charging of a battery, said receiver module having a coil running around an axial direction; a motherboard having a top section extending perpendicular to the axial direction and in a radial direction; and said top section and said receiver module being stacked in the axial direction.

2. The hearing device according to claim 1, wherein: said motherboard has a side section connected to said top section and a bottom section connected to said side section; and said motherboard being arranged to wrap around said receiver module with said receiver module being disposed between said top section and said bottom section.

3. The hearing device according to claim 1, wherein: said receiver module comprises a ferrite; and said motherboard has a circumference formed such that said motherboard, at least partially, does not extend beyond the ferrite in the radial direction and/or does not cover the ferrite when viewed in the axial direction.

4. The hearing device according to claim 3, wherein the circumference is formed to leave uncovered at least 50% of the ferrite when viewed in the axial direction.

5. The hearing device according to claim 3, wherein the circumference is formed with one or more arc-shaped recesses for exposing the ferrite when viewed in the axial direction.

6. The hearing device according to claim 1, wherein: said receiver module comprises a ferrite; and said motherboard comprises a ground plane formed such that said ground plane, at least partially, does not extend beyond the ferrite in the radial direction and/or does not cover the ferrite when viewed in the axial direction.

7. The hearing device according to claim 6, wherein the ground plane is formed to leave uncovered at least 50% of the ferrite when viewed in the axial direction.

8. The hearing device according to claim 6, wherein the ground plane is formed with one or more arc-shaped recesses for exposing the ferrite when viewed in the axial direction.

9. The hearing device according to claim 1, further comprising a holding frame holding said motherboard and said receiver module and fixing said motherboard and said receiver module relative to one another.

10. The hearing device according to claim 9, wherein: said holding frame has a plurality of brackets extending in the axial direction; and each of said brackets has a shoulder in which said receiver module rests and an arm on which said motherboard rests.

11. The hearing device according to claim 10, wherein: said holding frame comprises a plate connected to each of said brackets; and said plate extends in the radial direction and is stacked with said receiver module and said top section of said motherboard in the axial direction.

12. The hearing device according to claim 9, wherein: said top section of said motherboard and said receiver module are disposed with a gap in between; and said holding frame is configured to set said gap at a fixed spacing distance within a tolerance of at most 0.15 mm.

13. The hearing device according to claim 1, further comprising a customized shell encasing said motherboard and said receiver and formed to worn in a given user's ear canal.

14. The hearing device according to claim 1, being an in-the-ear hearing aid or a completely-in-the-canal hearing air.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0039] FIG. 1 is a perspective view of an exemplary hearing device;

[0040] FIG. 2 is a perspective view of a motherboard, a receiver module and a holding frame for the hearing device from FIG. 1;

[0041] FIG. 3 is a side view of the motherboard and receiver module of FIG. 2;

[0042] FIG. 4 is an exploded view of some components of the hearing device from FIG. 1;

[0043] FIG. 5 is a sectional view of some components of the hearing device from FIG. 1;

[0044] FIG. 6 is a top view of a motherboard and receiver module and a trimming region;

[0045] FIG. 7 is a plan view onto a motherboard and conducting elements thereon;

[0046] FIG. 8 is a top plan view of the motherboard with trimmed regions and the receiver module from FIG. 2;

[0047] FIG. 9 is a plan view of the motherboard of FIG. 2 and conducting elements thereon;

[0048] FIG. 10 is a schematic view of a magnetic field simulation for the motherboard and receiver module from FIG. 2 in combination with a transmitter module;

[0049] FIG. 11 is another view of the magnetic field simulation from FIG. 10; and

[0050] FIG. 12 is a chart of the distribution of the resonance frequency shift after assembly.

DETAILED DESCRIPTION OF THE INVENTION

[0051] FIG. 1 shows an exemplary embodiment of a hearing device 2. The hearing device 2 shown here is an ITE hearing device 2 comprising a customized shell 4, to be worn in a particular user's ear canal. The hearing device 2 in FIG. 2 also comprises a face plate 6, which faces outwards when worn, and a sound outlet 8, which faces inwards when worn to output sound to the user by using a speaker. Sound is input and recorded by the hearing device 2 with a microphone which is situated behind a sound inlet 10.

[0052] The hearing device 2 comprises a motherboard 12, a receiver module 14 and a battery (not shown). The receiver module 14 is configured for wireless charging of the battery and therefor comprises a coil 16, which runs around an axial direction A, i.e., around a longitudinal axis which extends in the axial direction A. Wireless charging is achieved via interaction with a magnetic field H, which is created by a transmitter module 19, e.g. with an antenna 18 (here an NFMI antenna), of a corresponding charger (not shown). The coil 16 picks up the magnetic field H and corresponding energy, which is then used for charging the battery. The charger is designed and oriented such that the magnetic field H at the coil 16 generally runs in the axial direction A and, thus, through the coil 16 (cf. simulation in FIGS. 10 and 11).

[0053] An exemplary embodiment of a combination of a motherboard 12 and receiver module 14 is shown in FIGS. 2 to 5 in various views and partially in combination with other components of the hearing device 2. The motherboard 12 comprises electrical and/or electronic components 20 such as ICs, resistors, capacitors, microphones, speakers and the like to implement one or several features. The motherboard 12 also comprises conducting elements 22 (cf. FIGS. 7, 9), such as conductor paths or planes, each typically made from copper. The motherboard 12 generally is a PCB 24 (printed circuit board) on which such components 20 are mounted and connected to each other as required via suitable conducting elements 22. The motherboard 12 described here comprises a top section 26, which extends perpendicular to the axial direction A and in a radial direction R. The top section 26 and the receiver module 14 are stacked in the axial direction A, as illustrated, e.g., in the perspective view of FIG. 2, the side view of FIG. 3, and the exploded view of FIG. 4. As such, the top section 26 comprises two opposing sides, one of which faces the receiver module 14 and the other facing away from the receiver module 14. Components 20 and conducting elements 22 may be mounted on either side.

[0054] The motherboard 12 shown here also has a side section 28 connected to the top section 26 and a bottom section 30 connected to the side section 28. As can be seen, e.g., in FIGS. 2 and 3, the motherboard 12 is arranged such that it wraps around the receiver module 14 with said receiver module 14 located between the top section 26 and the bottom section 30. Thus, a sandwiched configuration (as a special case of the stacked configuration) is realized, in which the receiver module 14 is sandwiched between top and bottom sections 26, 30. The side section 28, then, extends in the axial direction A and connects the top and bottom sections 26, 30. The side section 28 optionally has a center section 32, which connects to the top and bottom sections 26, 30, and a number of wings 34 attached to the center section 32 and embracing or folded around the receiver module 14 in a circumferential direction, such that the receiver module 14 is almost encapsulated by the motherboard 12, as illustrated in FIGS. 2 and 3. The motherboard 12 shown in FIG. 2 to 5 is shown in FIG. 9 in an unfolded configuration.

[0055] In addition to the coil 16, the receiver module 14 comprises a ferrite 36, for enhancing the magnetic coupling during wireless charging. The coil 16 generally comprises one or several turns, which run around the axial direction A, such that a stack of turns is formed and the coil 16 has a helical shape, extending in the axial direction A, as, e.g., visible in FIGS. 3 and 5. In the example shown here, the turns are circular, such that the coil 16 has the shape of a tube extending in the axial direction A and a radius measured in the radial direction R. The ferrite 36 follows the turns of the coil 16 and, correspondingly, has a tube-like shape. The ferrite 36 is located inside the coil 16, such that the coil 16 runs along an outwards facing surface of the ferrite 36. The ferrite 36 and the coil 16 are positioned and fixed relative to each other with a fixing ring 38. Also, the coil 16 and ferrite 36 are configured such that the battery is located inside of these. The battery generally has a cylindrical shape, with a radius that fits inside the coil 16 and ferrite 38.

[0056] The motherboard 12 shown here, more precisely its top section 26, comprises a circumference C, which is designed (here trimmed) such that it at least partially does not extend beyond the ferrite 36 in the radial direction R and does not cover the ferrite 36 when viewed in the axial direction A. This is particularly visible in the top view of FIG. 8. The motherboard 12 has a reduced extension in the radial direction R, which is also visible in FIG. 9, thereby exposing the ferrite 36 when viewed in the axial direction A, which is also, in general, the direction of the magnetic field H. In other words: one or more sections at the border of the motherboard 12 are left out and its circumference C is recessed or trimmed in the radial direction R, to better expose the ferrite 36 to the magnetic field H.

[0057] The motherboard 12 also comprises a ground plane 40, which extends over a substantial (i.e., at least 50%) area of the top section 26 and constitutes the main obstacle for the magnetic field H. Hence, this ground plane 40 is designed (here trimmed) such that it at least partially does not extend beyond the ferrite 36 in the radial direction R and does not cover the ferrite 36 when viewed in the axial direction A. The ground plane 40 and its peculiar shape are best visible in FIG. 9.

[0058] When starting from a motherboard 12 or ground plane 40 which entirely covers the ferrite 36, e.g., as shown in FIGS. 6 and 7 for comparison, an embodiment such as in FIGS. 8 and 9 is achieved by trimming the entire motherboard 12 or at least its ground plane 40 in the radial direction R and at the edges (i.e., at the circumference C), preferably as much as possible. In this approach, the motherboard's 12 circumference C and/or ground 40 plane comprises one or more trimmed regions 42, which are recessed (FIGS. 8 and 9) when compared to the original configuration (FIGS. 6 and 7) and which have a reduced extension in the radial direction R. A suitable area for trimming is indicated in FIG. 6 by the trimming region T. These trimmed regions 42 are free of any conducting material and, hence, provide free passage for the magnetic field H. In the example shown here, the circumference C and ground plane 40 are designed such that at least 50% of the ferrite 36 remains uncovered by them when viewed in the axial direction A. Since the ferrite 36 is tube-shaped, the trimmed regions 42 are here arc-shaped. Correspondingly, the circumference C and the ground plane 40 are formed to that each has one or more arc-shaped (also C-shaped) recesses 44 for exposing the ferrite 36 when viewed in the axial direction A.

[0059] FIGS. 10 and 11 show different views of a simulation of the magnetic field H flowing through the ferrite 36 and the coil 16 with the specially trimmed motherboard 12 as shown of FIG. 9 in an assembled hearing device 2 which is charged from a transmitter module 19 via an antenna 18. As shown in FIGS. 10 and 11, the magnetic field H flows around the motherboard 12 while maintaining a high concentration after passing the motherboard 12 and not being blocked off by the motherboard 12.

[0060] This is further verified by measurements to compare the performance of a non-trimmed motherboard (as in FIGS. 6 and 7) and a trimmed motherboard 12 (as in FIGS. 8 and 9). The measured performance parameter is based on the inductance value and quality factor. Table 1 below shows the corresponding results. For the non-trimmed motherboard the inductance (L) is reduced by 19.57 nH while the inductance in the case of the trimmed motherboard 12 is only reduced by 13.07 nH after the receiver module 14 is assembled into the hearing device 2. Similarly, the quality factor for the non-trimmed motherboard 12 is reduced by 9.66 as compared to only 8.19 for the trimmed motherboard 12 after assembly.

TABLE-US-00001 TABLE 1 Difference between receiver module only Receiver module Assembled hearing and assembled only device hearing device Q at Q at Q at L at 13.56 13.56 L at 13.56 13.56 L at 13.56 13.56 Sample MHz (nH) MHz MHz (nH) MHz MHz (nH) MHz Non-trimmed 233.66 45.69 214.09 36.03 ?19.57 ?9.66 motherboard Trimmed 231.89 44.51 218.82 36.32 ?13.07 ?8.19 motherboard

[0061] Another measurement is carried out to verify that the shift of resonance frequency after assembly into the hearing device 2 is lower for a trimmed motherboard 12 than for a non-trimmed motherboard 12. The results are shown in Table 2 below. The results show that the resonance frequency shift for the non-trimmed motherboard is 0.478 MHz, while for the trimmed motherboard 12 it is only 0.362 MHz.

TABLE-US-00002 TABLE 2 Resonance frequency(MHz) Shifted Pure battery Assembled Resonance Sample coil module Hearing Aid frequency(MHZ) Non-trimmed 13.184 13.662 0.478 copper trace motherboard Trimmed copper 13.186 13.548 0.362 trace motherboard

[0062] In addition, a simulation is carried out to study the coupling factor between the receiver module 14 of the hearing device 2 and transmitter module 19 of the charger and the coil-to-coil efficiency. The comparison samples are a hearing device 2 with a non-trimmed motherboard 12 a hearing device 2 with a trimmed motherboard 12. The simulation is conducted with a distance of 2 mm and 7 mm measured from top of the antenna to the bottom of the receiver module 14. The coupling factor and efficiency results are shown in table 3 below. For magnetic resonance wireless charging, a higher coupling factor means the coil-to-coil efficiency is larger, which will result in higher overall charging efficiency. The 2 mm distance shows a higher coupling factor and higher coil-to-coil efficiency than the 7 mm distance. The non-trimmed motherboard has a lower coupling factor and a lower coil-to-coil efficiency compared to the trimmed motherboard 12.

TABLE-US-00003 TABLE 3 Distance 2 mm 7 mm Measurement Coupling Coil-to-coil Coupling Coil-to-coil factor efficiency factor efficiency Non-trimmed copper 0.0360 43.3 0.0317 39.7 trace motherboard Trimmed copper 0.0391 47.3 0.0344 42.7 trace motherboard

[0063] In general, a gap 46 is formed between the motherboard's 12 top section 26 and the receiver module 14, the gap 46 usually spanning a spacing distance D on the order of 0.5 mm to 1 mm in the axial direction A (in an analogous manner, a corresponding gap and distance are formed between the bottom section 30 and the receiver module 14). This gap 46 and distance D may vary. Hence, in the embodiment shown here, a resonance frequency tolerance control is implemented by introducing a holding frame 48 to guarantee as little variation of the gap 46 and distance D as possible. The holding frame 48 holds the motherboard 12 and the receiver module 14 and fixes them relative to each other. This is shown particularly well in FIG. 5. In this particular example, wireless charging does not occur through the faceplate, but from the other side, i.e., from above in FIG. 5, which is the side on which the top section 26 is located.

[0064] The holding frame 48 is also visible in the exploded view of FIG. 4. The holding frame 48 shown here has several brackets 50 extending in the axial direction A, wherein each bracket 50 has a shoulder 52 in which the receiver module 14 rests and an arm 54 on which the motherboard 12 rests, as visible in FIG. 5. The brackets 50 are connected to each other via a plate 56 and surround and grab the receiver module 14. The motherboard 12 is placed on top of this, such that the gap 46 between the receiver module 14 and the motherboard 12 is defined by the positions of the arms 54. The shoulders 52 are facing inwards and are formed as recesses on an inside of each bracket 50. The arms 54 extend into the radial direction R and inwards, such that they extend over the coil 16 and ferrite 36.

[0065] The holding frame 48, receiver module 14 and motherboard 12 shown here are designed such that during assembly the receiver module 14 (and battery) are inserted sideways between the motherboard's 12 top and bottom section 26, 30 to achieve a stacked configuration and this combination of motherboard 12 and receiver module 14 is inserted into the holding frame 46 in the axial direction A, such that the shoulders 52 and arms 54 of the brackets 50 act as a limit stop to the axial insertion and, hence, fix the motherboard 12 and receiver module 14 in a defined and precise way.

[0066] The plate 56, which is connected to each of the brackets 50, extends in the radial direction R and is stacked with the receiver module 14 and the motherboard's 12 top and bottom sections 26, 30 in the axial direction A. The plate 56 has a roughly circular shape and is formed with one or more cut-outs 58 to accommodate parts of the motherboard 12 and/or to allow access to the motherboard 12. The plate 56 is located at the bottom and, hence, close to the motherboard's 12 bottom section 30.

[0067] The holding frame 48 keeps the spacing distance D between the receiver module 14 and the motherboard 12 at a fixed value with a particularly small tolerance. In other words: the holding frame 48 is designed such that the gap 46 is set to a fixed distance D (measured in the axial direction A) within a tolerance of at most 0.15 mm. In the exemplary embodiment shown here, the tolerance is the sum of a first tolerance for resting the receiver module 14 on the shoulders 52 and a second tolerance for resting the motherboard 12 on the arms 54.

[0068] Measurements are carried out to verify the impact of the holding frame 48 on the resonance frequency shift after assembling the receiver module 14 into the hearing device 2. The resonance frequency of the receiver module 14 is measured for 100 hearing devices 2 before and after assembly and the difference is calculated to obtain the resonance frequency shift between these two conditions. The results are shown in FIG. 12, showing the distribution resonance frequency shift caused by the assembly for 100 hearing devices 2. The results show a range of 0.32 MHz to 0.48 MHz for the resonance frequency shift, with the majority of values in a range of 0.38 MHz to 0.44 MHz. For an exemplary target resonance frequency of the assembled hearing device 2 of 13.56 MHz, the resonance frequency is kept within a range of 13.08 MHz to 13.24 MHz.

[0069] Another feature of the holding frame 48 is to reduce any variation of the resonance frequency in the assembled hearing device 2 upon the impact of an external force, such as a drop to the floor. To verify this, table 4 lists results from a corresponding drop test from 1 m above ground with four assembled hearing devices 2. Table 4 shows the measured resonance frequency before (pre-test) and after (post-test) the drop. The results show that the resonance frequency difference between pre-test and post-test does not vary more than the 0.06 MHz.

TABLE-US-00004 Resonance Frequency (MHz) Sample Pre-test Post-test 1 13.65 13.64 2 13.656 13.646 3 13.62 13.592 4 13.628 13.574

[0070] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: [0071] 2 hearing device [0072] 4 shell [0073] 6 face plate [0074] 8 sound outlet [0075] 10 sound inlet [0076] 12 motherboard [0077] 14 receiver module, battery module [0078] 16 coil [0079] 18 antenna [0080] 19 transmitter module [0081] 20 component [0082] 22 conducting element [0083] 24 PCB [0084] 26 top section [0085] 28 side section [0086] 30 bottom section [0087] 32 center section [0088] 34 wing [0089] 36 ferrite [0090] 38 fixing ring [0091] 40 ground plane [0092] 42 trimmed region [0093] 44 recess [0094] 46 gap [0095] 48 holding frame [0096] 50 bracket [0097] 52 shoulder [0098] 54 arm [0099] 56 plate [0100] 58 cut-out [0101] A axial direction [0102] C circumference [0103] D spacing distance [0104] H magnetic field [0105] R radial direction [0106] T trimming region