United States Patent
`Mattatall
`
`115
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`-
`
`[u1)
`[45)
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`4,379,988
`. Apr. 12, 1983
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`[76]
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`[54] MOLDED HEARING AID AND BATTERY
`CHARGER
`Inventor:
`
`Patricio Mattatall, P.O. Box 910,
`Winter Park, Fla. 32789
`[21] Appl. No.: 226,212
`[22] Filed:
`Jan, 19, 1981
`[51] Ent, C03 vaccccccsssscsccceeeeeen H02J 7/02; HO4R 25/02
`[52] US. Ch. ecceecccceecssisesseseecssseeees 320/4; 179/107 R;
`320/48
`[58] Field of Search. ................... 179/107 R; 320/2,4,
`320/48
`
`ABSTRACT
`{57]
`A moldedhearingaid ofthe self-containing type having
`a rechargeable battery disposed therein, in the form of a
`molded plug which will fit in the ear of the user. A light
`emitting diode is disposed through the external surface
`of the plug andis internally connected in series with an
`iron core inductor with the series combination in paral-
`_el with the internal chargeablebattery. A battery char-
`ger is provided having a cup for receiving the molded
`plug and having a multiturn coil wound around the
`periphery of the cup. The coil is connected into an
`oscillator circuit and tuned to cause the circuit to oscil-
`late at about 30 kHz. Theoscillator coil couples to the
`.
`:
`.
`:
`:
`:
`References Cited
`iron core inductorin the plastic plug thereby inducing a
`:
`30 kHz ac voltage across the coil. The light emitting
`U.S. PATENT DOCUMENTS
`diode rectifies the alternating current and is connected
`3,195,540
`7/1965 Waller ...scsecsssscsssesesssesens 320/2 UX
`
`in a polarity so as to charge the internal battery of the
`3,493,695
`2/1970 Stork......
`.. 179/107 R
`
`3,867,950 2/1975 Fischell... . 320/2 X.hearing aid. As the charging current flows through the
`
`
`3,885,211
`5/1975 Gutai..
`320/2
`ight emitting diode, the diodeis illuminated indicating
`rea ion pan .*
`320/2
`to the user that charging is taking place and indicating
`we
`005,
`eander..
`320/2 X
`.
`:
`:
`wa:
`.
`AAT413 12/1979 ASCOLi casessceserseseeceeneene 320/48 x_byits brillance when the hearing aid is located in its
`optimum position.
`—
`Primary Examiner—A.D. Pellinen
`Attorney, Agent, or Firm—-Duckworth, Allen, Dyer &
`Pettis
`:
`
`6 Claims, 7 Drawing Figures
`
`APPLE 1070
`Apple v. GUI
`IPR2021-00471
`
` 1
`
`[56]
`
`1
`
`APPLE 1070
`Apple v. GUI
`IPR2021-00471
`
`

`

`U.S. Patent
`
`Apr. 12, 1983
`
`Sheet 1 of 2
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`4,379,988
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`LINE OSCILLATOR
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`2
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`Sheet 2 of 2
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`4,379,988
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`U.S. Patent
`
`Apr. 12, 1983
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`3
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`2
`LEDprojects slightly from the outer face of the hear-
`ing aid unit and the light produced by the LED is a
`positive indication to the user that the battery is being
`charged. It has been found that the maximum energy
`BACKGROUND OF THE INVENTION
`transfer from the oscillator to the inductor occurs when
`1. Field of the Invention
`the hearing aid portion containing the inductor is as
`The present invention relates to a battery charging
`close as possible to the oscillator coil winding. The
`system for miniature hearing aid devices having an
`LED thuswill indicate by its brightness when the user
`internal rechargeable battery and more particularly to a
`has the hearing aid located in its optimum position.
`system which provides positive indication to the user
`It is therefore a principal object of the invention to
`that the battery is charging.
`provide a self-contained miniature hearing aid that can
`2. Description of the Prior Art
`be inserted in the user’s ear and in which a self-con-
`Rapid advancements have been madein the hearing
`tained rechargeable battery can be recharged with no
`aid technology with the advent of microelectronic cir-
`physical connection to the hearing aid unit.
`cuits. For example, it is now possible to provide a hear-
`It is another object of the invention to provide a
`ing aid in the form of a molded plug whichwillfit in the
`miniature hearing aid in whichaself-contained battery
`ear of the user and which contains an integrated circuit
`amplifier, input and output transducers, a volume con-
`can be charged with no physical connection thereto and
`trol and switch, and a rechargeable battery. However,
`which provides a positive indication to the user that
`due to the requirement for very small size, the batteries
`charging is in progress.
`such as are now in common use have a small energy
`It is still another object of the invention to provide a
`storage capacity and therefore must frequently be re-
`charging system for a self-contained rechargeable bat-
`charged. In knownpriorart hearing aids of the self-con-
`tery in a miniature hearing aid having an oscillator
`tained type,
`it is common to have extremely small,
`which can be coupled to an inductor disposed within
`receptacle-type contacts embedded in ‘the device. At
`the hearing aid to transfer energy thereto.
`night or at other times when the hearing aid is not in
`It is yet another object of the invention to provide a
`use, the user plugs a cable from a battery charger into
`hearing aid having an LED which simultaneously recti-
`such contacts for recharging of the battery. Due to the
`fies induced ac voltage in the hearing aid inductor for
`small sizes required for such connectors and the fre-
`charging a self-contained battery and to provide visible
`quent use thereof; many problems are experienced from
`indication that charging is taking place.
`wear and breakage of the contacts, poor connections,
`and similar mechanical type problems. Another factor
`It is a further object of the invention to provide a
`which makes such charging system somewhat unsatis-
`miniature hearing aid having a self-contained recharge-
`factory is that many wearers of hearing aids are elderly
`able battery and a charging system for the battery
`and have poor eyesight. This leads to difficulties for
`which can be used by elderly and infirm persons by
`such users in making the necessary connection and to
`simply dropping the miniature hearing aid unit into a
`inadvertent damage during attemptsto plugin the bat-
`small plastic cup.
`tery charger.
`It is yet a further object of the invention to provide a
`The present invention overcomes such problems and
`battery charging system for a miniature hearing aid
`difficulties experienced with-prior art battery charging
`which provides a small amount of heat to the hearing
`systems for small, self-contained hearing aid devices.
`aid unit during charging to minimize the effects of hu-
`SUMMARYOF THE INVENTION
`midity on the life of the hearing aid unit.
`These and other objects and advantagesof the inven-
`tion will become apparent from the following detailed
`description of the drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
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`MOLDED HEARING AID AND BATTERY
`CHARGER
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`4,379,988
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`The present invention dispenses entirely with the
`requirement of a mechanical and electrical. connection
`betweenthe hearing aid unit and the battery charger. A
`small iron core inductor is molded into the body ofthe
`hearing aid and a light emitting diode (LED)is con-
`nected in series with the inductor across the recharge-
`able battery. The LEDis polarized to match thepolar-
`ity of the battery. A battery charger is provided which
`includesa small plastic cup. A tapped inductoris wound
`around the outside of the cup and is connected into an
`oscillator circuit to form an oscillator operating at about
`30 kHz. A line connected dc power supply provides
`powerto the oscillator.
`When the battery in the hearing aid is to be re-
`charged, the user removes the device from his ear and
`placesit in the plastic cup in the magnetic field present
`within the oscillator coil. The inductor in the hearing
`aid body is disposed so as to provide maximum induc-
`tive coupling to the oscillator coil and therefore, an ac
`voltage at the frequencyofoscillation is induced in the
`inductor. The LED actsas a dioderectifier to rectify
`the induced ac voltage to provide a pulsating dc charg-
`ing circuit to the hearing aid battery. At the same time
`that the LEDis acting as a rectifier, it also emits visual
`radiation. Advantageously,
`the bulb portion of the
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`FIG.1 is a perspective view of a hearing aid battery
`charging system in accordance with the invention
`which provides for charging of two batteries simulta-
`neously;
`FIG. 2 is a schematic diagram of the charging system
`for the unit shown in FIG.1;
`FIG.3 is a partial and cut away view of the charging
`cup used with the system of FIG. 1;
`FIG. 4 is a cross sectional and partial view of the
`charging cup showing the configuration of the electri-
`cal circuit components;
`FIG.5 is a top view of the charging cup with a hear-
`ing aid unit placed therein for charging of a battery;
`FIG.6 is a partially cut away view of a miniature
`hearing aid showing the special elements for charging
`of an internal battery in accordance with the invention;
`and
`FIG.7 is a simplified schematic diagram of the hear-
`ing aid of FIG.6.
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`3
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`DETAILED DESCRIPTION OF THE
`INVENTION
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`4,379,988
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`Turning first to FIG. 1, I have shown a perspective
`view of a typical charging unit of the invention in a case
`5 having a top panel 10. The unit depicted therein has
`provisions for simultaneously charging the internal bat-
`tery for two hearing aids 20. Two charging cups 12 are
`mounted in panel 10 and adapted to permit hearing aids
`20 to be droppedinto the cup portion. Primary poweris
`supplied from a 115 volt ac line via plug 11 with on/off
`switch 14 and powerlamp 16 utilized to turn the unit off
`and on. While I have showna dual unit in FIG.1,it will
`be apparent that the charging unit can be implemented
`singly or in multiple units as is required by the user.
`FIG. 2 represents a schematic diagram for the char-
`ger shown in FIG.1. The unit consists of three sections:
`a dc powersupply 30;a first oscillator 40 and a second
`oscillator 50. Although any suitable type of power sup-
`ply may be used, the very small amount of energy re-
`quired advantageously permits the use of a simple half-
`waverectifier circuit utilizing diode 32,limiting resistor
`31, and filter capacitor 33. Pilot lamp 16 may be an
`LED with a series dropping resistor 34. Oscillator 40
`utilizes tapped coil 22 resonated by capacitor 24 to the
`desired operating frequency said tapped coil providing
`the necessary positive feedback for oscillation. This
`frequency is not critical; however, I have found that a
`frequency of about 30 kHz providesefficient operation
`of the system. Transistor 26 is therefore used in con-
`junction with resonator circuit formed by coil 22 and
`capacitor 24 to form oscillator 40. Resistor 28 and ca-
`pacitor 29 serve as a decoupling network and to drop
`the supply voltage to the voltage required by transistor
`26. Oscillator 50 is identical to oscillator 40 and is sup-
`plied power via decoupling network comprising resis-
`tor 51 and capacitor 52.
`Turning now to FIG.3, a cutaway view of panel 10
`with charging cup 12 installed therein is shown. Refer-
`ring to FIG. 3 and FIG.4, it may be noted that coil 22
`is wound around the outer periphery of cup 12. The
`bottom of cup 12 includes a series of openings 21.
`Referring to FIG. 4, case 5 is shownin cross-section
`with charging cup 12 partially cut away. As may be
`noted, I place a printed circuit board 41 immediately
`below. the bottom surface of cup 12. Printed circuit
`board 41is utilized to mount the various electrical com-
`ponents indicated in FIG. 2. As may be understood,
`direct rectification of the 115 volt line voltage in the
`power supply of FIG. 2 may produce a dc voltage of
`about 150 volts. It is necessary to drop this voltage
`downto a value suitable for transistor 26 whichis usu-
`ally in the 6-12 volt range. Therefore, the majority of
`the input energy to the power supply unit will be dissi-
`pated as heat from dropping resistors 28 and 51. Advan-
`tageously, I take advantage of this heat which will rise
`through openings 21 as shown by the wavyarrows H.
`Whena hearing aid unit is placed in cup 12 for charging
`of its internal battery, as will be explained more fully
`below,this relatively small amount of heat will dry out
`moisture which may have collected in and around the
`hearing aid unit during wearing by the user from hu-
`midity, and from perspiration and the like. I have found
`that the useful life of the miniature hearing aid can be
`significantly extended by preventing ultimate intrusion
`of moisture into the electronic circuits of the hearing
`aid.
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`In FIG. 5, I have shown a top view of the miniature
`hearing aid 20 placed in charging cup 12. The hearing
`aid of the invention is custom. molded to fit exactly in
`the user’s ear with a portion of the body 61 projecting
`into the ear canal through which the amplified sound
`from the output transducer is conducted. Body 61 in-
`cludes a flat surface which projects outward from the
`user’s ear, and mounts a switch and volume control
`knob 62 with which the user can turn the unit on and off
`and adjust the sound level to an appropriate point. An
`opening is also provided leading to the input transducer
`or microphone. Also on this panel, the bulb end of an
`LED 64 projects slightly. Referring now to FIG.6, a
`partial cross sectional view of hearing aid 20 is shown
`with body 61 partially cut away. A small coil 65 is
`mounted having a magnetic core and is disposed with
`the central axis essentially vertical
`in the position
`shown. LED 64 is seen with oneside thereof connected
`to coil 65.
`FIG. 7 gives a simplified schematic diagram of the
`hearing aid 20. As shown, inductor 65 in series with
`LED 64 is connected in parallel with the internal re-
`chargeable battery 66. The remainderofthe hearing aid
`is not part of my invention and is shownto indicate the
`load which battery 66 sees during use ofthe hearingaid.
`Microphone70is the input transducer which drives an
`integrated circuit amplifier 74 which in turn operates
`output transducer 72. Control knob 62 operates switch
`73 and volumecontrol 75.
`Having now described the circuitry and construction
`of my miniature hearing aid and battery charger, the use
`thereof will now be described. Due to the limitations of
`space in hearing aid 20, battery 66 has relatively small
`capacity, typically 20.ma/hr. Thus, even though the
`electronics of FIG. 7 requires only a small amount-of
`power,it is necessary to recharge battery 66 frequently.
`It is usual for the user to removethe hearing aid at night
`while sleeping and to utilize that time for charging of
`battery 66. Whenthe user desires to place the battery on
`charge, he removes the hearing aid from his ear and
`places it in charging cup 12 as shown in the top view,
`FIG. 5. This act places inductor 65 in the center of
`oscillator coil 22 with the axes of inductor 65 and coil 22
`in parallel. Therefore, the magnetic field produced by
`coil 22 induces an electromagnetic force in coil 65.
`Referring to FIG. 7, it may be noted that the induced
`voltage across coil 65, which will be at the samefre-
`quency as that of oscillator 40, will produce current
`flow through light emitting diode 64 and battery 66 in a
`direction to recharge battery 66. As is apparent, LED
`64 acts as a half-wave diode rectifier and each half-wave
`rectified pulse of voltage will produce a corresponding
`pulse of current through battery 66 as desired. As LED
`64 passes the rectified current, the emission of light
`occurs, as is well known, and the portion of LED 64
`projecting abovethe flat portion of body 61 of hearing
`aid 20 as seen in FIGS. 5 and 6 will glow brightly. Thus,
`the user is aware that the charger is properly operating
`and the battery is indeed being charged.
`This indication is of great value since it will generally
`prevent the user from placing his hearing aid into the
`charging cup and neglecting to turn on the primary
`power to the charger. The LED serves an additional
`function in permitting the user to optimally position
`hearing aid 20 in charging cup 12. I have found that, due
`to the small size of inductor 65, that maximum coupling
`occurs when the portion of hearing aid 20 containing
`inductor 65 is in its closest proximity to coil 22 and
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`therefore LED 64 will be brightest in such position.
`The user merely positions the hearing aid 20 such that
`the portion containing LED 64 touches an inner wall of
`charging cup 12. As will be noted from FIG.6, the axis
`of LED 64 is essentially aligned with that of coil 65 and
`permits LED 64 to indicate mechanically the portion of
`the body 61 that is to be in contact with the inner wall
`of cup 12. The hearing aid 20 may draw about 0.4 to 0.5
`ma whenin use and a charging rate of about 2 ma is
`satisfactory. During chargingit is desirable that switch
`73 be in the off position to eliminate any drain during
`the charging operation.
`As may nowberecognized, I have disclosed a simple
`and very reliable battery charging system for a minia-
`ture hearing aid having aninternal rechargeable battery
`and which can be safely andeasily operated by elderly
`and infirm persons. It is only necessary to place the
`hearing aid in a smallplastic cup and to adjustthe posi-
`tion for a maximum brightness of the LED indicator in
`the hearing aid which assures the user that the position
`is Optimum and that charging is taking place. Since I
`provide no plugsorelectrical contacts and the coupling
`between the charging unit and the hearingaid is purely
`inductive, no trouble will be experienced in poor or
`broken connections as in prior art units.
`While I have shownspecific circuits and mechanical
`construction in the preferred embodiment,
`it will be
`obvious to those ofskill in the art that many other con-
`figurations of the hearing aid holder, the oscillator coil,
`the pick up inductor, and other parts may be made
`without departing from the scope or the spirit of the
`invention.
`I claim:
`1. A self-contained hearing aid insertable in the ear of
`the user and having a rechargeable battery, the battery
`charging system comprising:
`oscillator means for producing electrical oscillations;
`a first inductor associated with said oscillator means
`for producing an inductive magnetic field from said
`electrical oscillations;
`holding means for supporting said hearing aid for
`charging said rechargeable battery;
`a second inductor disposed within said hearing aid,
`said holding means supporting said hearingaid in a
`manner to inductively couple said first inductor
`and said second inductor whereby an electromo-
`tive force is induced in said second inductor; and
`a light emitting diode disposed in said hearing aid and
`visible externally thereto, said diode connected in
`series with said second inductor, the series combi-
`nation of said diode and said second inductor con-
`nected in parallel with said battery, whereby said
`electromotive force induced in said second induc-
`tor causing said diode to producea pulsatingdirect
`current flowing in the direction to charge said
`battery and to emit a light external to said hearing
`aid to indicate such flow of charging current, said
`hearing aid position adjustable within said holding
`meansby the user to maximize the degree of induc-
`tive coupling betweensaid first and second induc-
`tors, said light emitting diode functioning to indi-
`cate said degree of coupling by the intensity of
`emitted light therefrom.
`2. The system as defined in claim 1 in which said
`second inductor is a part of a resonantcircuit of said
`oscillator means.
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`3. The system as defined in claim 2 in which said
`hearing aid holding meansincludes:
`a cylindrical cup fabricated from a non-magnetic
`material having sufficient capacity to permit inser-
`tion of said hearing aid into said cup and to permit
`movementof said hearing aid within said cup; and
`a multiplicity of turns of a wire conductor forming
`windings around the external walls of said cup,said
`windings forming said first inductor.
`4. The system as defined in claim 3 in which said
`oscillator means comprises:
`dc power supply means; and
`a turning capacitor connected essentially in parallel
`with said first inductor for resonating said inductor
`to the desired frequency of oscillation;
`transistor means connected to said first inductor and
`said power supply, said connection including a
`positive feedback path so as to producesaid electri-
`cal oscillations.
`5. In a self-contained hearing aid for insertion in the
`ear of the user and having input and outputtransducers,
`audio amplifier means, control means, and a recharge-
`able battery, the improvement comprising:
`inductor meansfor coupling to an external source of
`ac electrical energy to induce an alternating volt-
`age in said inductor means;
`light emitting diode means connected in series with
`said inductor means, said light emitting diode pro-
`ducing a visual indication when dc charging cur-
`rent is flowing therethrough and indicating by
`maximum emitted light when the coupling between
`said inductor meansand said external source of ac
`electrical energy is optimized; and
`the series combination of said inductor means and
`said light emitting diode connected in parallel with
`said battery in a polarity to produce a dc charging
`current through said battery from such alternating
`voltage.
`6. In a self-contained hearing aid having a recharge-
`able battery in parallel with the series combination of an
`inductor and a diode, the battery charging system com-
`prising:
`at least one electrical oscillator having a resonant
`circuit including an air core inductor;
`de powersupply means connectedto said oscillator,
`the output of said dc power supply much greater
`than required by said oscillator;
`resistor voltage dropping means disposed between
`said power supply and said oscillator for reducing
`said output to that required by said oscillator, said
`dropping resistor thereby producing radiated heat;
`and
`non-magnetic hearing aid holding cup disposed
`within the air core of said air core inductor, said
`cup adapted to receive and hold said hearing aid in
`a position in which the axis of said hearing aid
`inductoris essentially parallel to the axis ofsaid air
`core inductorof said oscillator wherebyan electro-
`motive force is induced in said hearing aid induc-
`tor, said diode providing charging current to said
`rechargeable battery, said hearing aid holding cup
`having a multiplicity of openings in the bottom
`' surface thereof, said cup disposed directly over
`said voltage dropping resistor means wherebysaid
`radiated heat passes through said multiplicity of
`openings to thereby remove moisture from: said
`hearing aid held in said cup.
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