EP3614494B1 - Performant magnetically inductive antenna for a hearing aid - Google Patents

Description

The invention relates to a magnetically inductive antenna according to the preamble of claim 1 for a hearing instrument and to a hearing instrument, in particular a hearing aid, with such an antenna.

Background of the invention:

Electronic devices are generally referred to as hearing instruments which emit a sound signal into the ear of a person wearing the hearing instrument (also referred to as “user” or “wearer”) and thus support this person's hearing. In the narrower sense, this includes hearing aids that are used to care for hearing impaired wearers. Such hearing aids pick up ambient sound and emit it to the user in processed, in particular frequency-dependent, amplified form as airborne and / or structure-borne sound, wholly or at least partially compensating for the user's hearing loss. Other hearing instruments process - similar to classic hearing aids - a recorded ambient sound, but serve to supply normal hearing users in order to protect their hearing ability in special situations (e.g. special sound-absorbing hearing instruments for musicians) or to support them in some other way. In the following, hearing instruments are also understood to mean devices that convert a wired or wirelessly received audio signal into airborne or structure-borne sound and transmit it to the user in this form, e.g. headphones, ear pieces, etc.

There are known different designs of hearing instruments. So-called "behind-the-ear devices" are worn between the skull and the auricle, with the amplified sound signal entering the ear canal by means of a sound tube is introduced to the person or is output by means of a sound transducer (also referred to as "listener" or "receiver") sitting in the ear canal. Another embodiment of a hearing instrument is an "in-the-ear device" in which the entire hearing aid device itself is introduced into the ear, in particular into the auditory canal. There are also hearing instruments that transmit sound information in the form of structure-borne sound, for example so-called cochlear implants.

Magnetic inductive near-field transmission is used in hearing instruments as an alternative to classic radio transmission technologies (e.g. Bluetooth) for the wireless transmission of data, especially audio signals, with external devices. In particular, magnetically inductive near-field transmission is often used for the communication between two hearing instruments of a binaural hearing system.

Magnetic-inductive methods are also used for energy transmission, i.e. for wireless charging of rechargeable batteries in hearing instruments.

Up to now, the MI antennas required for this (i.e. for magnetic-inductive data and / or energy transmission) were usually produced by a bare, wound ferrite core. The antenna performance can be increased here with larger ferrite cores, special wrapping and special ferrite materials. Due to the restricted installation space, the sensitive (and therefore fault-prone) electronics in hearing instruments and the desire for the lowest possible weight, however, there are narrow limits to the increase in performance of conventional MI antennas for use in hearing instruments.

In WO 2017/153274 A1 describes a concept for new types of magneto-inductive antennas (MI antennas for short, i.e. antennas for magnetically inductive near-field transmission) in which the cross-section of the actual winding core (hereinafter: base) is expanded by flat magnetic foils. These antenna surfaces (referred to there as "screens") are aligned approximately orthogonally to the axis of the winding core. The antenna surfaces are optionally available with a para- or diamagnetic one on the inner sides facing one another Provided a layer through which the interior space formed between the antenna surfaces is magnetically shielded. Electrical or electronic components of the hearing aid (for example the battery) can therefore be accommodated in a space-saving manner in the interior space between the antenna surfaces.

A magnetically inductive antenna according to the preamble of claim 1 is from US 2007/132648 A1 known.

Other magnetically inductive antennas are off WO 2017/153274 A1 and EP 1 906 270 A2 known.

The invention is based on the object of further improving such a film antenna, in particular with regard to manufacturing aspects.

Subject of the invention:

The object is achieved according to the invention by the features of claim 1.

The MI antenna according to the invention comprises two antenna surfaces which are formed from magnetic, flexible film. The MI antenna further comprises a base wound with an antenna winding. According to the invention, the two antenna surfaces are formed from magnetic foil blanks that are separate from one another. The base has an opening on each of the end faces (ie the surfaces opposite one another in the direction of the winding axis) into which one of the foil blanks (in particular with a tab) is inserted. The MI antenna further comprises a base with a hollow (in particular one-piece) base body, preferably a ferrite core or alternatively a (winding) carrier made of non-magnetic material such as plastic or ceramic, into which the two foil blanks are inserted in such a way that they overlap or abut on the inside of the body. Optionally, the foil blanks are clamped by wedges introduced into the base body through the openings on the front side.

The MI antenna according to the invention has the advantage that the base can be prefabricated detached from the antenna surfaces, with the antenna winding in particular being able to be soldered in a reflow process in a favorable manner from a manufacturing point of view (and preferably also being). The foil blanks are only subsequently inserted into the openings of the prefabricated base. This production concept enables an inexpensive, automated production with conventional production machines. In addition, the inserted foil blanks can be used to achieve a flat overlap of the foil blanks with one another or with a ferrite core of the base, whereby an efficient magnetic flux between the base and the antenna surfaces and thus a high antenna efficiency are achieved.

Further embodiments of the invention are a hearing instrument equipped with the MI antenna according to the invention, in particular a hearing aid.

• in einem ersten Schritt eine mit einer Antennenwicklung bewickelte Basis hergestellt, so dass an den (wie vorstehend definierten) Stirnseiten dieser Basis Öffnungen freigelassen sind; in diesem ersten Schritt wird die Antennenwicklung vorzugsweise mit korrespondierenden Kontaktflächen auf der Basis verlötet,
• in einem zweiten Schritt zwei Antennenflächen als voneinander getrennte Folienzuschnitte aus magnetischer Folie hergestellt, und
• in einem dritten Schritt die Folienzuschnitte mit der Basis verbunden, indem jeder der beiden Folienzuschnitte jeweils (insbesondere mit einer zugehörigen Lasche) in eine der Öffnungen der Basis eingesteckt wird.

To manufacture the MI antenna, in particular

• in a first step, a base wound with an antenna winding is produced, so that openings are left free on the end faces of this base (as defined above); In this first step, the antenna winding is preferably soldered to corresponding contact surfaces on the base,
• In a second step, two antenna surfaces are produced as separate foil blanks from magnetic foil, and
• In a third step, the foil blanks are connected to the base by inserting each of the two foil blanks (in particular with an associated tab) into one of the openings in the base.

The first step and the second step are independent of each other. These steps can therefore be carried out in any chronological order (in particular also simultaneously or in a chronologically overlapping manner). The third step, on the other hand, builds on the result of the previous steps and must therefore timely after these are executed.

The foil blanks can in principle have any outer contour within the scope of the invention. In suitable embodiments, the antenna surfaces each have a circular, semicircular or polygonal outer contour, for example. The tabs to be inserted into the corresponding recesses in the base are preferably narrower than the associated antenna surface (that is, they have a smaller width compared to the antenna surface) and protrude from the edge of the antenna surface.

• Sandwich-artige Basis mit Träger aus nicht-magnetischem Material (Kunststoff, Keramik, etc.) und mit Ferritkern, wobei die Folienzuschnitte zwischen dem Träger und dem Ferritkern eingelegt sind.
• Anschluss der Antennenwicklung über einen - vorzugsweise flexiblen - gedruckten Schaltungsträger (Printed Circuit Board, kurz: PCB), der einseitig an den Ferritkern oder Träger der Basis angelegt oder um den Ferritkern oder Träger herumgefaltet ist.
• Ferritkern oder Träger mit elektrischen Kontaktflächen zur Kontaktierung der Antennenwicklung beschichtet
• Basis mit Ferritkern, der mindestens eine Vertiefung zur Aufnahme einer Lasche eines der Folienzuschnitte aufweist, sowie mit Deckschicht, die die oder jede Vertiefung abdeckt; Varianten:
  • ∘ zwei voneinander getrennte Vertiefungen für je eine Lasche
  • ∘ eine von Stirnseite zu Stirnseite durchgehende Vertiefung zur Aufnahme der Laschen beider Folienzuschnitte
• dia- oder paramagnetische Schicht (vorzugsweise aus Kupfer) auf die jeweilige Innenseite der Folienzuschnitte aufgebracht, insbesondere im Bereich der Antennenflächen (Laschen im Überlappungsbereich ohne dia- oder paramagnetische Beschichtung)

Preferred design features and variants of the invention furthermore:

• Sandwich-like base with a carrier made of non-magnetic material (plastic, ceramic, etc.) and with a ferrite core, the foil blanks being inserted between the carrier and the ferrite core.
• Connection of the antenna winding via a - preferably flexible - printed circuit board (PCB), which is placed on one side against the ferrite core or carrier of the base or folded around the ferrite core or carrier.
• Ferrite core or carrier coated with electrical contact surfaces for contacting the antenna winding
• Base with ferrite core, which has at least one recess for receiving a tab of one of the foil blanks, and with a cover layer that covers the or each recess; Variants:
  • ∘ two separate recesses for one tab each
  • ∘ a continuous recess from face to face to accommodate the tabs of both foil blanks
• dia- or paramagnetic layer (preferably made of copper) applied to the respective inside of the foil blanks, especially in the area of the antenna surfaces (tabs in the overlap area without dia- or paramagnetic coating)

Embodiments of the invention:

Corresponding parts are provided with the same reference symbols in all figures.

Embodiment 1 not claimed (Fig. 1 - 3):

Fig. 1

Explosionsdarstellung der Basis

Fig. 2

perspektivische Darstellung der Basis mit Blick auf eine Deckfläche

Fig. 3

perspektivische Darstellung der Basis mit Blick auf einen Boden

Show here

Fig. 1

Exploded view of the base

Fig. 2

perspective view of the base with a view of a top surface

Fig. 3

perspective view of the base with a view of a floor

• Ferritkern mit voneinander getrennten, jeweils zu einer Stirnseite offenen Vertiefungen zur Einführung jeweils einer Lasche eines der beiden Folienzuschnitte (der Steg zwischen Vertiefungen zwingt den Magnetfluss hierbei durch den Ferritkern, wodurch eine günstige magnetische Ankopplung der Antennenflächen an den Ferritkern bewirkt wird),
• einer bodenseitigen (von den Vertiefung abgewandten) PCB zum Verlöten der Antennenwicklung,
• einer die Vertiefungen abdeckenden Deckschicht (PCB, PTFE-Folie, etc.), und
• der um den Ferritkern, die PCB und die Deckschicht gewickelte Antennenwicklung, mit PCB im Reflow-Verfahren verlötet

Description of the not claimed embodiment: Base formed from

• Ferrite core with separate recesses, each open to one end face, for the introduction of a tab of one of the two foil blanks (the web between the recesses forces the magnetic flux through the ferrite core, which results in a favorable magnetic coupling of the antenna surfaces to the ferrite core),
• a bottom PCB (facing away from the recess) for soldering the antenna winding,
• a cover layer (PCB, PTFE film, etc.) covering the depressions, and
• the antenna winding wound around the ferrite core, the PCB and the cover layer, soldered to the PCB in a reflow process

The foil blanks not shown here are designed as in FIGS Fig. 4 and 10 (circular antenna surfaces each with a tab protruding from it at the edge), and are inserted with the tabs into the front openings of the base.

Embodiment 2 (FIGS. 4-6): show here

Fig. 4

perspective view of the MI antenna with base and two foil blanks made of magnetic foil (with inside diamagnetic layers of copper for magnetic shielding of the interior space formed between the foil blanks) in the assembled state Status

Fig. 5

Side view of the MI antenna in the assembled state

Fig. 6

Longitudinal section of the MI antenna in the assembled state

• Kunststoffträger mit ringförmig geschlossenen stirnseitigen Bügeln zur Einführung jeweils einer Lasche eines der beiden Folienzuschnitte und einem offenen Mittelbereich,
• einem Ferritkern, der in den offenen Mittelbereich des Trägers eingelegt ist, so dass er an den auf Stoß aneinanderliegenden Laschen der Folienzuschnitte flächig anliegt,
• einer bodenseitigen (von den Vertiefung abgewandten) PCB oder leitfähigen Beschichtung des Trägers zum Verlöten der Antennenwicklung, und
• der um den Träger und den Ferritkern (sowie ggf. die PCB) gewickelten Antennenwicklung

Base formed from

• Plastic carrier with ring-shaped closed end brackets for the introduction of a tab of one of the two foil blanks and an open central area,
• a ferrite core, which is inserted into the open central area of the carrier so that it rests flat against the butt-jointed tabs of the foil blanks,
• a bottom (facing away from the recess) PCB or conductive coating of the carrier for soldering the antenna winding, and
• the antenna winding around the carrier and the ferrite core (and possibly the PCB)

Embodiment 3 (FIGS. 7-9): show here

Fig. 7

Exploded view of the base

Fig. 8

perspective view of the base with a view of a top surface

Fig. 9

perspective view of the base with a view of a floor

• Ferritkern mit einer von Stirnseite zu Stirnseite durchgehenden Vertiefung zur Einführung der Laschen beider Folienzuschnitte (die Laschen liegen in dieser Vertiefung auf Stoß aneinander an),
• einer um den Ferritkern herumgefalteten PCB zum Verlöten der Antennenwicklung und zur Abdeckung der Vertiefung, und
• der um den Ferritkern und die PCB gewickelten Antennenwicklung

Base formed from

• Ferrite core with a recess extending from end face to end face for the introduction of the tabs of both foil blanks (the tabs are butt against each other in this recess),
• a PCB folded around the ferrite core for soldering the antenna winding and for covering the recess, and
• the antenna winding wrapped around the ferrite core and the PCB

The foil blanks not shown here are designed as in FIGS Fig. 4 and 10 (circular antenna surfaces each with a tab protruding from it at the edge), and are inserted with the tabs into the front openings of the base.

Embodiment 4 (FIGS. 10 and 11): show here

Fig. 10

Exploded view of the MI antenna with base and two foil cuts

Fig. 11

Longitudinal section of the MI antenna in the assembled state

• hohlem Ferritkern, in dem die Laschen überlappend und flächig aneinander anliegen, und
• der um den Ferritkern gewickelten Antennenwicklung

Base formed from

• hollow ferrite core in which the tabs overlap and lie flat against one another, and
• the antenna winding wound around the ferrite core

• Ausführungsbeispiel 5 (analog Fig. 10 und 11 ): wie Ausführungsbeispiel 4, aber mit Kunststoffträger statt hohlem Ferritkern
• Ausführungsbeispiel 6 (ohne Zeichnung): wie Ausführungsbeispiel 4, aber die Laschen liegen im Inneren des hohlen Ferritkerns auf Stoß aneinander an.
• Ausführungsbeispiel 7 (ohne Zeichnung): wie Ausführungsbeispiel 4, 5 oder 6, aber die Laschen sind im Inneren des hohlen Ferritkerns oder Kunststoffträgers durch stirnseitig eingeschobene Keile verklemmt.

In the assembled state, the diamagnetic copper layers are in contact with the antenna surfaces, as in Fig. 4-6 and 11 shown.

• Embodiment 5 (analog Figures 10 and 11 ): like embodiment 4, but with plastic carrier instead of hollow ferrite core
• Embodiment 6 (without drawing): as in embodiment 4, but the lugs butt against one another inside the hollow ferrite core.
• Embodiment 7 (without drawing) : like embodiment 4, 5 or 6, but the tabs are clamped inside the hollow ferrite core or plastic carrier by wedges inserted at the end.

The MI antenna is preferably used in a hearing instrument that picks up ambient noise and emits it in a processed, in particular amplified form into the ear of a person wearing the hearing instrument. The MI antenna is intended in particular for use in a hearing aid, that is to say a hearing instrument that is used to supply hearing-impaired people. In the hearing instrument, the MI antenna is mainly used for wireless data transmission with a peripheral device, e.g. B. another hearing instrument for the other ear, a remote control, etc. used.

As an alternative or in addition, the MI antenna according to the invention is used as a charging coil for inductive and wireless energy transmission from a charger, not shown, to the hearing instrument.

List of reference symbols

1. 1 MI antenna
2. 2 base
3. 3 Foil cut
4. 4 antenna surface
5. 5 tab
6. 6 diamagnetic layer of copper
7. 7 ferrite core
8. 8 recess in the ferrite core (to accommodate one tab or two tabs)
9. 9 cover sheet
10. 10 PCB
11. 11 Contact surface for contacting the antenna winding (printed conductor track)
12. 12 antenna winding
13. 13 (winding) carrier (plastic)
14. 14 bracket (of the wearer)
15. 15 Contact surface for contacting the antenna winding (applied to the carrier by means of a conductive coating)
16. 16 front side
17. 17 opening

Claims (9)

1. Magnetic-inductive antenna (1) for a hearing instrument, with two antenna surfaces (4) which are formed from magnetic, flexible foil, and with a base (2) wound with an antenna winding (12), wherein the antenna surfaces (4) are formed from separate magnetic foil blanks (3), which are separated from one another, and the base (2) comprises respectively one opening (17) on its end sides (16), into which respectively one of the foil blanks (3) is inserted,
   characterized in
   that the base (2) is formed from a hollow base body (7, 13), into which the two foil blanks (3) are inserted in such a way that they overlap in the interior of the base body or abut against one another.
2. Antenna (1) according to claim 1,
   wherein the base body (7, 13) is in one piece.
3. Antenna (1) according to claim 1 or 2,
   wherein the base body is a ferrite core (7) or a support (13) of non-magnetic material.
4. Antenna (1) according to one of claims 1 to 3,
   wherein the foil blanks (3) are clamped in the base body by wedges inserted into the openings (17) of the base body end faces.
5. Antenna (1) according to one of claims 1 to 4,
   wherein the base (2) comprises a support (13) of non-magnetic material, for example plastic or ceramic, and a ferrite core (7), wherein the foil blanks (3) are inserted between the support (13) and the ferrite core (7).
6. Antenna (1) according to one of claims 1 to 5,
   wherein the base (2), for electrically connecting the antenna winding (12), comprises a (preferably flexible) printed circuit board (10), said printed circuit board (10) having one side placed against the ferrite core (7) or support (13) or being folded around the ferrite core (7) or support (13).
7. Antenna (1) according to one of claims 1 to 5,
   wherein the ferrite core (7) or support (13) is coated with electrical contact surfaces (11) for contacting the antenna winding (12).
8. Antenna (1) according to one of claims 1 to 7,
   wherein the ferrite core (7) comprises at least one recess (8) open to at least one end face (16) for receiving a lug (5) of one of the foil blanks (3), and wherein the base (2) additionally comprises a covering layer (9), which covers the at least one recess (8).
9. Hearing instrument, in particular hearing aid, with an antenna (1) according to one of claims 1 to 8.

Images