U.S. patent application number 14/262320 was filed with the patent office on 2014-12-18 for using an audio cable as an inductive charging coil.
This patent application is currently assigned to APPLE INC.. The applicant listed for this patent is APPLE INC.. Invention is credited to Stephen Brian Lynch, Fletcher R. Rothkopf, Anna-Katrina Shedletsky.
Application Number | 20140369518 14/262320 |
Document ID | / |
Family ID | 44341673 |
Filed Date | 2014-12-18 |
United States Patent
Application |
20140369518 |
Kind Code |
A1 |
Rothkopf; Fletcher R. ; et
al. |
December 18, 2014 |
USING AN AUDIO CABLE AS AN INDUCTIVE CHARGING COIL
Abstract
The disclosed embodiments relate to a technique for inductively
charging an electronic device. This technique involves winding an
audio cable for the electronic device around a charging mechanism
multiple times so that one or more conductors in the audio cable
form an inductive receiving coil. Next, a magnetic field is created
through the charging mechanism to induce a current in the inductive
receiving coil. Finally, the induced current in the inductive
receiving coil is used to charge a rechargeable battery for the
electronic device.
Inventors: |
Rothkopf; Fletcher R.; (Los
Altos, CA) ; Shedletsky; Anna-Katrina; (Sunnyvale,
CA) ; Lynch; Stephen Brian; (Portola Valley,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
APPLE INC. |
Cupertino |
CA |
US |
|
|
Assignee: |
APPLE INC.
Cupertino
CA
|
Family ID: |
44341673 |
Appl. No.: |
14/262320 |
Filed: |
April 25, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12700518 |
Feb 4, 2010 |
8744098 |
|
|
14262320 |
|
|
|
|
Current U.S.
Class: |
381/74 |
Current CPC
Class: |
H04R 1/06 20130101; H04R
1/1091 20130101; H02J 7/00 20130101; H04R 25/00 20130101; H04R
1/1033 20130101 |
Class at
Publication: |
381/74 |
International
Class: |
H04R 1/10 20060101
H04R001/10; H04R 1/06 20060101 H04R001/06 |
Claims
1-11. (canceled)
12. A earphone comprising: an earphone body; a cable coupled to the
earphone body; a speaker housed in the earphone body and configured
to output a first acoustic signal corresponding to a media file,
the speaker including a transducer configured to generate a current
when it vibrates in response to a second acoustic signal provided
by a corresponding acoustic charging device; and a conductor
coupled to the transducer and the cable.
13. The earphone of claim 12 wherein a portion of the earphone body
is configured to be inserted into a recess of a corresponding
acoustic charging device.
14. The earphone of claim 12 wherein the cable is also coupled to
an electronic device that includes a charging circuit that is
configured to use the generated current to charge a battery of the
electronic device.
15. The earphone of claim 14 wherein the cable is further
configured to carry an audio signal from the electronic device to
the earphone, wherein the audio signal corresponds to the media
file.
16. The earphone of claim 12 wherein the earphone further comprises
a battery and a charging circuit that is configured to use the
generated current to charge the battery.
17. The earphone of claim 12 wherein the earphone further comprises
an audio driver.
18. The earphone of claim 12 wherein the earphone further comprises
a processor and memory configured to play the media file.
19. A method for acoustically charging a battery; receiving, by a
speaker of an earphone coupled to an acoustic charging device, an
acoustic signal that causes a transducer of the speaker to vibrate;
converting, by the transducer, a vibration of the speaker into a
current; passing, by a conductor coupled the speaker, the current
to a charging circuit; and charging, by the charging circuit, a
battery using the current.
20. The method of claim 19 wherein the acoustic signal is a first
acoustic signal, wherein the speaker is configured to output a
second acoustic signal corresponding to a media file.
21. The method of claim 20 further comprising receiving, by the
earphone and from an electronic device, an audio signal that
corresponds to the media file.
22. The method of claim 20 wherein the earphone further comprises a
processor and memory configured to play the media file.
23. The method of claim 19 wherein an electronic device coupled to
the earphone includes the battery.
24. The method of claim 19 wherein a portion of a body of the
earphone is configured to be inserted into a recess of the acoustic
charging device.
25. The method of claim 19 wherein a frequency of the acoustic
signal is less than about 20 Hz.
26. The method of claim 19 wherein a frequency of the acoustic
signal is greater than 20,000 Hz.
27. An acoustic charging device comprising: a housing having a
recess configured to receive a portion of a corresponding earphone;
and a speaker disposed within the recess and configured to provide
an acoustic signal that causes a corresponding speaker of the
corresponding earphone to vibrate such that a transducer of the
corresponding speaker generates a current for charging a battery
when the transducer vibrates in response to the acoustic
signal.
28. The acoustic charging device of claim 27 wherein the recess
further includes a gasket that extends along an inner surface of
the recess.
29. The acoustic charging device of claim 27 wherein a frequency of
the acoustic signal is less than about 20 Hz.
30. The acoustic charging device of claim 27 wherein a frequency of
the acoustic signal is greater than 20,000 Hz.
31. The acoustic charging device of claim 27 wherein the acoustic
signal is a first acoustic signal, wherein the speaker is further
configured to output a second acoustic signal corresponding to a
media file.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation of U.S. application Ser. No.
12/700,518, filed Feb. 4, 2010, and is hereby incorporated by
reference herein in its entirety for all purposes.
TECHNICAL FIELD
[0002] The disclosed embodiments generally relate to techniques for
charging portable electronic devices. More specifically, the
disclosed embodiments relate to a technique that uses an audio
cable as an inductive charging coil for a portable electronic
device.
RELATED ART
[0003] Rechargeable batteries are presently used to provide power
to a wide variety of portable electronic devices, including digital
music players, cell phones, PDAs, laptop computers, and cordless
power tools. These rechargeable batteries are typically charged
through a direct conductive connection between a transformer, which
is connected to either wall power or a car battery, and the
portable electronic device.
[0004] Inductive charging techniques, which operate without
requiring direct conductive connections, have been developed for
certain applications, such as electric toothbrushes, where the
proximity to water makes a conductive connection impractical. An
electric toothbrush can be recharged using a relatively small
inductive receiving coil because it is typically placed in a
charging stand for a long period of time (many hours) and is only
used for a short period of time (about two minutes).
[0005] However, to inductively charge other types of electronic
devices (such as portable media players or cell phones) at an
acceptable rate, a significantly larger receiving coil is required.
Providing this larger receiving coil involves either incorporating
the larger receiving coil into the portable electronic device,
which increases the size of the portable electronic device, or
alternatively incorporating the larger receiving coil into a bulky
attachment to the portable electronic device.
[0006] Hence, what is needed is a technique for inductively
charging portable electronic devices without the above-described
problems.
BRIEF SUMMARY OF THE INVENTION
[0007] The disclosed embodiments relate to a technique for
inductively charging an electronic device. This technique involves
winding an audio cable for the electronic device around a charging
mechanism multiple times so that one or more conductors in the
audio cable form an inductive receiving coil. Next, a magnetic
field is created through the charging mechanism to induce a current
in the inductive receiving coil. Finally, the induced current in
the inductive receiving coil is used to charge a rechargeable
battery for the electronic device.
[0008] In some embodiments, after winding the audio cable around
the charging mechanism, the technique further involves electrically
coupling a first contact, which is coupled to the one or more
conductors in the audio cable, to a second contact associated with
the electronic device to complete a circuit between the inductive
receiving coil and the electronic device.
[0009] In some embodiments, the second contact is located on a body
of the electronic device. In further variation, the second contact
comprises a conductive body of the electronic device.
[0010] In some embodiments, the first contact is located on a first
earphone (e.g., an earbud) which is attached to the audio cable. In
a further variation, the first contact is conductive metal mesh
screen that also protects a driver for the first earphone.
[0011] In some embodiments, the second contact is located on a
second earphone which is also attached to the audio cable. In a
further variation, electrically coupling the first and second
contacts involves electrically coupling the first and second
contacts through an intervening conductor, wherein the intervening
conductor is located in a housing which is configured to hold the
first and second earphones.
[0012] In some embodiments, the one or more conductors within the
audio cable include multiple conductors which are coupled in series
to form a single receiving coil having more windings than an audio
cable with only a single conductor.
[0013] In some embodiments, the audio cable comprises: a headphone
cable; an earphone cable; or a microphone cable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 illustrates how a charging tower is used to
inductively charge a portable electronic device in accordance with
the disclosed embodiments.
[0015] FIG. 2 illustrates the structure of a charging tower in
accordance with the disclosed embodiments.
[0016] FIG. 3 illustrates a media player in accordance with the
disclosed embodiments.
[0017] FIG. 4 illustrates an earphone in accordance with the
disclosed embodiments.
[0018] FIG. 5 illustrates an audio device in accordance with the
disclosed embodiments.
[0019] FIG. 6 presents a flow chart illustrating the process of
using an audio cable as an inductive charging coil to charge a
portable electronic device in accordance with the disclosed
embodiments.
[0020] FIG. 7 illustrates an alternative charging system that uses
an acoustic output to charge a portable media player in accordance
with the disclosed embodiments.
DETAILED DESCRIPTION
[0021] The following description is presented to enable any person
skilled in the art to make and use the disclosed embodiments, and
is provided in the context of a particular application and its
requirements. Various modifications to the disclosed embodiments
will be readily apparent to those skilled in the art, and the
general principles defined herein may be applied to other
embodiments and applications without departing from the spirit and
scope of the disclosed embodiments. Thus, the disclosed embodiments
are not limited to the embodiments shown, but are to be accorded
the widest scope consistent with the principles and features
disclosed herein.
[0022] The data structures and code described in this detailed
description are typically stored on a computer-readable storage
medium, which may be any device or medium that can store code
and/or data for use by a computer system. The computer-readable
storage medium includes, but is not limited to, volatile memory,
non-volatile memory, magnetic and optical storage devices such as
disk drives, magnetic tape, CDs (compact discs), DVDs (digital
versatile discs or digital video discs), or other media capable of
storing code and/or data now known or later developed.
[0023] The methods and processes described in the detailed
description section can be embodied as code and/or data, which can
be stored in a computer-readable storage medium as described above.
When a computer system reads and executes the code and/or data
stored on the computer-readable storage medium, the computer system
performs the methods and processes embodied as data structures and
code and stored within the computer-readable storage medium.
Furthermore, the methods and processes described below can be
included in hardware modules. For example, the hardware modules can
include, but are not limited to, application-specific integrated
circuit (ASIC) chips, field-programmable gate arrays (FPGAs), and
other programmable-logic devices now known or later developed. When
the hardware modules are activated, the hardware modules perform
the methods and processes included within the hardware modules.
Charging Technique
[0024] The disclosed embodiments use an audio cable of a portable
music player as the "receiving" coil (or receiving loop) of an
inductive charger. More specifically, FIG. 1 illustrates how a
charging tower 102 can be used to inductively charge a portable
electronic device, such as a media player 108. As illustrated in
FIG. 1, charging tower 102 is coupled to a charger base 112, which
receives power through a power cord 114. (Note that charging tower
102 is described in more detail below with reference to FIG. 2.)
One contact for the receiving coil is on the body of media player
108, and other contact 110 is located on one of the earphones.
[0025] During the charging process, a user keeps the audio jack 106
attached to media player 108. The audio cable 104 for the headphone
is then wrapped around charging tower 102. Note that charging tower
102 contains inductive "transmitting" coils, which are similar to
transmitting coils in existing inductive charging systems, such as
a rechargeable toothbrush. Next, the user attaches a contact from
one of the earphones (by magnetic or other connector) back to the
media player 108 to complete the inductive receiving coil.
[0026] In an alternative embodiment, instead of completing the
inductive receiving coil by coupling a contact on one earphone to
an associated contact located on media player 108, the inductive
receiving coil is completed by coupling together two contacts
located on the earphones. In this case, each earphone has a contact
which is coupled to a different set of conductors in the audio
cable, and the act of coupling the contacts together completes the
inductive receiving coil.
[0027] Note that the speed of the inductive charging generally
increases with the length of the inductive receiving coil.
Consequently, a long receiving coil is desirable to achieve a
reasonable charging rate, and such longer receiving coils can be
hard to provide in a small portable electronic device. In a sense,
using audio cable 104 as the inductive receiving coil effectively
provides a long receiving coil "for free," because the long audio
cable 104 is already being used to carry audio signals. As an
example of how cumbersome such receiving coils can become, the Palm
Pre.TM. uses a bulky snap-on attachment to facilitate inductive
charging. Moreover, for some extremely small media players, such as
the iPod Shuffle.TM., the weight of the media player is
approximately the same as the weight of the headphones and
associated cable. Hence, by using the headphones as inductive
coils, an extremely small media player can effectively use about
half of its mass as a charging coil.
Charging Tower
[0028] FIG. 2 illustrates the structure of charging tower 102 in
accordance with the disclosed embodiments. Note that charging tower
102 is coupled to a charger base 112, which supports charging tower
102 and contains a transformer 202 and a transmitting coil 206.
During operation, transformer 202 receives power through a power
cord 114 which is coupled to a wall socket. Transformer 202
converts the voltage of the A/C power received from the wall socket
and uses the resulting voltage to drive transmitting coil 206.
[0029] Transmitting coil 206 is wrapped around a ferromagnetic core
204 which runs the length of charging tower 102. A time-varying
current flowing through transmitting coil 206 creates a varying
magnetic flux in ferromagnetic core 204, which creates a
time-varying magnetic field through a receiving coil that is
wrapped around charging tower 102. This time-varying magnetic field
induces a time-varying current in the receiving coil. Next, the
time-varying current in the receiving coil is used to charge the
associated electronic device. Note that using ferromagnetic core
204 improves the magnetic flux and hence improves the charging
efficiency. However, the magnetic flux can also propagate through
air, which means that the system can also work without a
ferromagnetic core.
[0030] As mentioned previously, the receiving coil is formed by
wrapping audio cable 104 around charging tower 102 and then
attaching a first contact 110 (which can be located on an earphone
of audio cable 104) to a second contact. This second contact can be
located either on the body of the electronic device or on the other
earphone of audio cable 104.
[0031] Also note that charging tower 102 is configured to allow a
user to easily wrap audio cable 104 around the charging tower 102.
For example, the surface of charging tower 102 can be textured
(instead of smooth), or may contain grooves, to allow audio cable
104 to rest on charging tower 102 without slipping when audio cable
104 is wrapped around charging tower 102. Although the embodiment
of charging tower 102 illustrated in FIG. 2 is cylindrical, any
shape that audio cable 104 can be wrapped around can be used. For
example, charging tower 102 may be conical. Also, instead of being
oriented vertically, charging tower 102 can be oriented
horizontally, or somewhere between horizontal and vertical.
Media Player
[0032] FIG. 3 illustrates the structure of a media player 108 in
accordance with the disclosed embodiments. In general, the
disclosed techniques will work with any type of portable electronic
device that operates on battery power. For example, the portable
electronic device can be a media player, such as an iPod.TM., which
can play both audio or video files. The portable electronic device
can also be a personal digital assistant (PDA), a cellular
telephone, a smart phone, or even a portable computer system.
[0033] Audio cable 104 can include any type of cable which carries
an audio signal. For example, audio cable 104 can include a
headphone cable, an earphone cable or a microphone cable. Moreover,
the disclosed techniques are not limited to audio cables. In
general, the disclosed techniques can be used with any type of
cable that is attached to a portable electronic device. For
example, the disclosed techniques can also be used with a network
interface cable or a video cable.
[0034] The media player 108 which is illustrated in FIG. 3 includes
an audio cable interface 312, a charging circuit 310, a battery
308, a display 302 and a circuit block 304, which contains a CPU
and a memory, as well as audio-visual (AN) drivers. Battery 308 can
include any type of rechargeable battery for a portable electronic
device, such as a lithium-ion or lithium-polymer battery. Note that
battery 308 provides power to all of the circuits in media player
108, including circuit block 304.
[0035] Circuit block 304 includes a CPU and a memory that enable
media player 108 to play selected media files, such as audio files,
image files or video files. These media files can be stored in
non-volatile memory, or alternatively, in a magnetic storage
device, such as a disk drive. Circuit block 304 also contains
circuitry for driving a display and circuitry for driving earphones
(or other types of audio output devices) that are coupled to an
audio cable 104, wherein audio cable 104 is attached to audio cable
interface 312.
[0036] Audio cable interface 312 also includes connections from one
or more conductors in the audio cable 104 to charging circuit 310.
Note that audio cable 104 can include one or more conductors, which
are separate from the audio conductors, and are used to form the
inductive receiving coil. Alternatively, audio cable 104 can use
the same conductors which are used to carry audio signals to form
the inductive receiving coil. (This alternative implementation
requires some additional switching circuitry to enable the same
conductors to carry both audio signals and inductive charging
signals.)
[0037] Audio cable 104 can also include multiple conductors which
are coupled in series (in a spiral arrangement) when the receiving
coil is closed. This forms a single receiving coil having more
windings than if the audio cable contained only a single conductor.
Note that this implementation may require the contact 110 on audio
cable 104 to provide multiple contacts which can be used to
simultaneously connect the multiple coils into the spiral
arrangement. Contact 110 may additionally include some type of
magnetic connector which holds the contact against a corresponding
opposing contact.
[0038] Charging circuit 310 is also electrically coupled through a
connection 314 to the conductive housing of media player 108. This
enables the entire conductive housing of media player 108 to
function as a second contact to complete the inductive receiving
coil. For example, the inductive receiving coil can be completed by
placing a contact, which is located on an earphone of audio cable
104, on the conductive housing of media player 108.
[0039] During the charging process, charging circuit 310 uses a
time-varying current, which is received through the inductive
receiving coil, to recharge battery 308.
Electrical Contact Through Earphone Mesh
[0040] FIG. 4 illustrates how an earphone 404 can include a
conductive metal mesh screen 410 which also functions as an
electrical contact. Note that this metal mesh screens also protects
the driver for earphone 404. Also note that this type of electrical
contact is different from the electrical contact 110 illustrated in
FIG. 1, which is located on the housing of an earphone, and is
separate from the screen which protects the earphone driver.
[0041] This type of electrical contact (through the earphone mesh)
can also be used to receive current for a conventional
non-inductive charging system. This eliminates the need to provide
a separate interface to receive the charging current in a
conventional charging system.
[0042] In one variation, this conductive metal mesh screen 410
includes a number of separate conductive regions which function as
independent contacts. In this way, the metal mesh screen can
provide multiple contacts instead of a single contact. These
separate conductive regions can be created by fabricating the mesh
using alternating regions of conductive metal wires and
non-conductive plastic wires.
Alternative Embodiment
[0043] An alternative embodiment for an audio player is illustrated
in FIG. 5. As can be seen from FIG. 5, the circuitry for this
alternative embodiment is integrated into two separate modules
501-503 which are coupled together by an audio cable 507. More
specifically, module 501 includes an audio driver 506, a battery
502 and a charger circuit 504, wherein the charger circuit 504 is
configured to charge battery 502. In contrast, module 503 includes
a CPU and memory unit 508 which controls the operation of the audio
player. During audio playback, the CPU and memory unit 508
generates audio signals which are transmitted to driver 510 in
driver 503 and driver 506 in driver 501 (through audio cable
507).
[0044] Note that charger circuit 504 in module 501 receives one
connection to the inductive receiving coil from metal mesh screen
523 (which protects driver 506 in module 501), and the other
connection through audio cable 507 from metal mesh screen 524
(which protects driver 510 in module 503). After audio cable 507 is
wound around a charging device, a conductive connection is
established between metal mesh screen 523 and metal mesh screen 524
to complete the inductive receiving coil. For example, this
conductive connection can be established through an intervening
conductor. Alternatively, metal mesh screens 523 and 524 can be
directly connected to each other to establish the conductive
connection. Note that using metal mesh screens 523 and 524 as
electrical contacts saves space because no additional connectors or
contacts need to be provided.
Charging Process
[0045] FIG. 6 presents a flow chart illustrating the process of
using an audio cable as an inductive charging coil to charge a
portable electronic device in accordance with the disclosed
embodiments. At the start of the process, a user winds an audio
cable for the electronic device around a charging mechanism
multiple times so that one or more conductors in the audio cable
form an inductive receiving coil (step 602). Next, the user
connects a first contact, which is coupled to the one or more
conductors in the audio cable, to a second contact to complete a
circuit between the inductive receiving coil and the electronic
device (step 604). A time-varying magnetic field is then generated
through the charging mechanism to induce current in the inductive
receiving coil (step 606). Finally, the induced current in the
inductive receiving coil is used to charge a rechargeable battery
for the electronic device (step 608).
Acoustic Charging
[0046] FIG. 7 illustrates an alternative charging system that uses
an acoustic output to charge a portable media player in accordance
with the disclosed embodiments. In the acoustic charging system
illustrated in FIG. 7, an earphone 404 is fitted into a recess in
an acoustic charger 702. This recess can be lined with a rubber
gasket to achieve a tighter fit. Next, a speaker 704 within
acoustic charger 702 produces an acoustic signal which causes a
corresponding speaker in earphone 404 to vibrate. These vibrations
cause a transducer within speaker 706 to effectively operate "in
reverse" to generate a current in earphone conductors 708. This
current can be used to charge the battery of the attached portable
electronic device. Note that the vibrations can be generated in a
non-audible frequency range (less than 20 Hz or greater than 20K
Hz) to prevent users from hearing the acoustic charging signal.
[0047] The foregoing descriptions of embodiments have been
presented for purposes of illustration and description only. They
are not intended to be exhaustive or to limit the present
description to the forms disclosed. Accordingly, many modifications
and variations will be apparent to practitioners skilled in the
art. Additionally, the above disclosure is not intended to limit
the present description. The scope of the present description is
defined by the appended claims.
* * * * *