U.S. patent application number 13/708627 was filed with the patent office on 2013-04-18 for inductive charging including use of after-market accessories.
This patent application is currently assigned to MOJO MOBILITY, INC.. The applicant listed for this patent is MOJO MOBILITY, INC.. Invention is credited to Afshin Partovi.
Application Number | 20130093388 13/708627 |
Document ID | / |
Family ID | 43623861 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130093388 |
Kind Code |
A1 |
Partovi; Afshin |
April 18, 2013 |
INDUCTIVE CHARGING INCLUDING USE OF AFTER-MARKET ACCESSORIES
Abstract
A system and method for inductive charging including use of
after-market accessories. In accordance with an embodiment, the
system comprises a receiver coil or receiver associated with a
mobile device, and provided as a separable or after-market
accessory for use with the mobile device. When the mobile device is
placed in proximity to a base unit having one or more charger
coils, the charger coil is used to inductively generate a current
in the receiver coil or receiver associated with the mobile device,
to charge or power the mobile device. In accordance with various
embodiments, the receiver can be a component of or attached to a
shell, case, or other cover of the mobile device, provided as an
after-market accessory that replaces an original shell, case, or
cover, or connected to a power input jack of the mobile device
and/or to battery connectors within the mobile device.
Inventors: |
Partovi; Afshin; (Sunnyvale,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MOJO MOBILITY, INC.; |
Sunnyvale |
CA |
US |
|
|
Assignee: |
MOJO MOBILITY, INC.
Sunnyvale
CA
|
Family ID: |
43623861 |
Appl. No.: |
13/708627 |
Filed: |
December 7, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12769586 |
Apr 28, 2010 |
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13708627 |
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12116876 |
May 7, 2008 |
8169185 |
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12769586 |
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61173497 |
Apr 28, 2009 |
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61178807 |
May 15, 2009 |
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61184659 |
Jun 5, 2009 |
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61223673 |
Jul 7, 2009 |
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61223669 |
Jul 7, 2009 |
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61304320 |
Feb 12, 2010 |
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61317946 |
Mar 26, 2010 |
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Current U.S.
Class: |
320/108 ;
320/137 |
Current CPC
Class: |
H01F 5/003 20130101;
H02J 7/0029 20130101; H02J 50/80 20160201; H04B 5/0037 20130101;
H01F 38/14 20130101; H02J 7/00304 20200101; H02J 50/005 20200101;
H02J 7/00045 20200101; H02J 50/10 20160201; H02J 5/00 20130101;
H02J 7/00034 20200101; H02J 7/02 20130101; H02J 50/70 20160201 |
Class at
Publication: |
320/108 ;
320/137 |
International
Class: |
H02J 7/02 20060101
H02J007/02 |
Claims
1. A system for inductive charging including use of after-market
accessories, comprising: a receiver coil or receiver associated
with a mobile device, and provided as a separable or after-market
accessory for use with the mobile device; and wherein, when the
mobile device is placed in proximity to a base unit having one or
more charger coils, the charger coil is used to inductively
generate a current in the receiver coil or receiver associated with
the mobile device, to charge or power the mobile device.
2. The system of claim 1, wherein the receiver coil or receiver is
a component of, or is attached to a shell, case, or other cover of
the mobile device, provided as an after-market accessory that
replaces an original shell, case, or cover of the mobile
device.
3. The system of claim 1, wherein the receiver coil or receiver is
connected to a power input jack of the mobile device and/or to
battery connectors within the mobile device.
4. The system of claim 1, wherein the base unit and mobile device
communicate with each other prior to and/or during charging or
powering to verify the authenticity, power requirements and/or
other characteristics of the mobile device or a battery therein
and/or verify or handshake the presence of the mobile device
proximate the base unit.
5. The system of claim 1, wherein the receiver coil or receiver is
integrated into a mobile device case or battery door which includes
a mobile device connector that mates with a corresponding power
connector of the mobile device, to provide power and/or data to the
mobile device.
6. The system of claim 1, wherein the receiver coil or receiver is
integrated into a mobile device case or battery door which connect
with a power input jack of the mobile device and include a
pass-through that allows for connection of a wired power and/or
data cable.
7. The system of claim 1, wherein the receiver coil or receiver is
incorporated into a rechargeable battery for use with the mobile
device.
8. The system of claim 1, wherein the base unit is integrated
within an automobile.
9. The system of claim 1, wherein the base unit is integrated
within an automobile, and wherein the base unit includes one or
more components for providing context-aware connectivity and/or
other capabilities with a mobile device including, upon charging or
powering the mobile device, configuring various aspects of the
automobile environment.
10. The system of claim 1, wherein the mobile device is an
automobile.
11. A method of inductive charging including use of after-market
accessories, comprising the steps of: providing a receiver coil or
receiver associated with a mobile device, and provided as a
separable or after-market accessory for use with the mobile device;
and wherein, when the mobile device is placed in proximity to a
base unit having one or more charger coils, the charger coil is
used to inductively generate a current in the receiver coil or
receiver associated with the mobile device, to charge or power the
mobile device.
12. The method of claim 11, wherein the receiver coil or receiver
is a component of, or is attached to a shell, case, or other cover
of the mobile device, provided as an after-market accessory that
replaces an original shell, case, or cover of the mobile
device.
13. The method of claim 11, wherein the receiver coil or receiver
is connected to a power input jack of the mobile device and/or to
battery connectors within the mobile device.
14. The method of claim 11, wherein the base unit and mobile device
communicate with each other prior to and/or during charging or
powering to verify the authenticity, power requirements and/or
other characteristics of the mobile device or a battery therein
and/or verify or handshake the presence of the mobile device
proximate the base unit.
15. The method of claim 11, wherein the receiver coil or receiver
is integrated into a mobile device case or battery door which
includes a mobile device connector that mates with a corresponding
power connector of the mobile device, to provide power and/or data
to the mobile device.
16. The method of claim 11, wherein the receiver coil or receiver
is integrated into a mobile device case or battery door which
connect with a power input jack of the mobile device and include a
pass-through that allows for connection of a wired power and/or
data cable.
17. The method of claim 11, wherein the receiver coil or receiver
is incorporated into a rechargeable battery for use with the mobile
device.
18. The method of claim 11, wherein the base unit is integrated
within an automobile.
19. The method of claim 11, wherein the base unit is integrated
within an automobile, and wherein the base unit includes one or
more components for providing context-aware connectivity and/or
other capabilities with a mobile device including, upon charging or
powering the mobile device, configuring various aspects of the
automobile environment.
20. The method of claim 11, wherein the mobile device is an
automobile.
Description
CLAIM OF PRIORITY AND CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/769,586, titled SYSTEM AND METHODS FOR
INDUCTIVE CHARGING, AND IMPROVEMENTS AND USES THEREOF", filed Apr.
28, 2010; which application is a continuation-in-part of U.S.
patent application Ser. No. 12/116,876, titled "SYSTEM AND METHOD
FOR INDUCTIVE CHARGING OF PORTABLE DEVICES", filed May 7, 2008;
which application claims the benefit of priority to U.S.
Provisional Patent Applications Application No. 61/173,497, titled
"CONTEXTUALLY AWARE POWER AND COMMUNICATION FOR USE WITH MOBILE
DEVICES", filed Apr. 28, 2009; Application No. 61/178,807, titled
"CONTEXTUALLY AWARE POWER AND COMMUNICATION FOR USE WITH MOBILE
DEVICES", filed May 15, 2009; Application No. 61/184,659, titled
"SYSTEM AND METHOD FOR IMPROVED WIRELESS CHARGING AND POWER
TRANSFER", filed Jun. 5, 2009; Application No. 61/223,673, titled
"SYSTEM AND METHOD FOR IMPROVED WIRELESS CHARGING AND POWER
TRANSFER", filed Jul. 7, 2009; Application No. 61/223,669, titled
"SYSTEM AND METHOD FOR WIRELESS CHARGING OF DEVICES AND BATTERIES",
filed Jul. 7, 2009; Application No. 61/304,320, titled "SYSTEM AND
METHOD FOR PROVIDING WIRELESS POWER CHARGERS, RECEIVERS AND
BATTERIES", filed Feb. 12, 2010; and Application No. 61/317,946,
titled "SYSTEMS AND METHODS FOR PROVIDING OR FOR USE WITH WIRELESS
POWER CHARGERS, RECEIVERS AND BATTERIES", filed Mar. 26, 2010;
which application is related to U.S. Patent Applications
Application No. 60/763,816, titled "PORTABLE INDUCTIVE POWER
SOURCE", filed Jan. 31, 2006; Application No. 60/810,262, titled
"MOBILE DEVICE, CHARGER, AND POWER SUPPLY", filed Jun. 1, 2006;
Application No. 60/810,298, titled "MOBILE DEVICE, BATTERY,
CHARGING SYSTEM, AND POWER SUPPLY SYSTEM", filed Jun. 1, 2006;
Application No. 60/868,674, titled "SYSTEM AND METHOD FOR PROVIDING
AND USING A PORTABLE INDUCTIVE POWER SOURCE", filed Dec. 5, 2006;
application Ser. No. 11/669,113, titled "INDUCTIVE POWER SOURCE AND
CHARGING SYSTEM", filed Jan. 30, 2007; application Ser. No.
11/757,067, titled "POWER SOURCE, CHARGING SYSTEM, AND INDUCTIVE
RECEIVER FOR MOBILE DEVICES", filed Jun. 1, 2007; Application No.
60/916,748, titled "SYSTEM AND METHOD FOR CHARGING AND POWERING
MOBILE DEVICES, BATTERIES, AND OTHER DEVICES", filed May 8, 2007;
Application No. 60/952,835, titled "SYSTEM AND METHOD FOR INDUCTIVE
CHARGING OF PORTABLE DEVICES", filed Jul. 30, 2007; Application No.
61/012,922, titled "WIRELESS CHARGER WITH POSITION INSENSITIVITY TO
PLACEMENT OF MOBILE DEVICES", filed Dec. 12, 2007; Application No.
61/012,924, titled "SYSTEM AND METHOD FOR PROVIDING CONTROL,
REGULATION, AND COMMUNICATION IN CHARGERS AND POWER SUPPLIES",
filed Dec. 12, 2007; Application No. 61/015,606, titled "WIRELESS
CHARGER WITH POSITION INSENSITIVITY TO PLACEMENT OF MOBILE AND
ELECTRONIC DEVICES", filed Dec. 20, 2007; and application Ser. No.
12/116,876, titled "SYSTEM AND METHOD FOR INDUCTIVE CHARGING OF
PORTABLE DEVICES", filed May 7, 2008; each of which above
applications are herein incorporated by reference.
COPYRIGHT NOTICE
[0002] A portion of the disclosure of this patent document contains
material which is subject to copyright protection. The copyright
owner has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure, as it appears in the
Patent and Trademark Office patent file or records, but otherwise
reserves all copyright rights whatsoever.
FIELD OF INVENTION
[0003] The invention is related generally to power supplies and
other power sources and chargers and particularly to inductive
charging, and to improvements, systems and methods for use thereof,
such as improved transfer of wireless power to mobile devices and
batteries.
BACKGROUND
[0004] With the increased use of mobile devices, many methods and
protocols for wireless and wired connectivity and communication
between nearby devices (several centimeters to meters) and also
between devices and the wider network of farther devices (tens of
meters to thousands of kilometers) are proliferating. For near
devices, Bluetooth, WiFi, Wireless USB, Zigbee, Near Field
Communication (NFC), HDMI, USB, Firewire, RS232, GPIB, etc., and
other specialized device or application specific protocols are
common, while for larger distances devices may include wireless
technologies such as 2G, 3G, 4G, GSM, Edge, WiMAX, EVDO, Satellite,
Optical, or GPS etc. or wired technologies such as Ethernet, Dial
up modem, DSL, Fiber, Power Line, etc. may coexist in a single
device.
[0005] While these technologies provide huge advantages to users in
connectivity and communication, the vast majority of electronics
have so far been powered or charged through traditional use of
wired power supplies and chargers.
[0006] Recently, there has been an interest in providing a
universal wireless method for powering or charging one or several
mobile devices, batteries, or electronics devices in general
simultaneously. These "wireless power" methods can be generally
divided into conductive and inductive methods. While the conductive
methods use flow of current from a charger and/or power supply into
the mobile devices to provide power and therefore are not strictly
speaking wireless, they offer geometries where a user can place a
device on a pad or similar object and receive power through
matching contacts on the back of a device and the pad without
`plugging in` the device. The inductive methods (including
variations such as magnetic resonance) utilize coils or wires in a
charger and/or power supply to create a magnetic field in the
vicinity of the surface. A coil or wire in a receiver embedded into
or on a device or battery that is in the vicinity of the surface
can sense the magnetic field. Power from the charger and/or power
supply can be transferred to the receiver without any wired
connection through air or other media in between.
[0007] However despite advances in "wireless power", both with the
conductive and inductive approaches, little progress has been made
in terms of increasing efficiency, such as improved transfer of
wireless power, and new uses and applications for such systems.
This is the general area that embodiments of the invention are
intended to address.
SUMMARY
[0008] Described herein are various systems and methods for use
with power supplies and other power sources and chargers and
particularly those that use inductive charging, including systems
and methods for use thereof, such as improved transfer of wireless
power to mobile devices and batteries.
[0009] In accordance with some embodiments described herein,
various methods are described by which the wired and/or wireless
power devices and chargers or power supplies can provide additional
connectivity and communications capabilities. In this way, in
addition to charging, during the charging or docking process, other
activities that are useful to the user can be implemented.
[0010] In accordance with some embodiments described herein,
features can be provided that overcome several shortcomings of
previous approaches, including methods by which the wireless power
devices and chargers or power supplies can provide better thermal
performance, better detection of external objects, and better power
transfer efficiencies, and can enable operation at greater distance
between charger and receiver coils.
[0011] In accordance with some embodiments described herein, a
wireless charger system or system for transfer of power wirelessly
can be provided in several different geometries and/or modes.
[0012] In accordance with some embodiments described herein, a
device is described by which the wireless charger and/or power
supply is a device that is powered by a power source from another
device such as the power available from the USB or PCMCIA port or
similar from a laptop computer or a peripheral hub or consumer
electronic or communication device such as a music player, TV,
video player, stereo, or car stereo USB or other outlets which
include power.
[0013] In accordance with some embodiments described herein,
features can be provided to improve charging efficiency, usage, and
other features, and can be used in combination with systems and
methods described, for example, in U.S. patent application Ser. No.
11/669,113, filed Jan. 30, 2007 (published as U.S. Patent
Publication No. 20070182367); U.S. patent application Ser. No.
11/757,067, filed Jun. 1, 2007 (published as U.S. Patent
Publication No. 20070279002); and U.S. patent application Ser. No.
12/116,876, filed May 7, 2008, (published as U.S. Patent
Publication No. 20090096413), each of which applications are
incorporated by reference herein.
BRIEF DESCRIPTION OF THE FIGURES
[0014] FIG. 1 shows an illustration of a circuit in accordance with
an embodiment.
[0015] FIG. 2 shows an illustration of a circuit in accordance with
an embodiment.
[0016] FIG. 3 shows an illustration of a circuit in accordance with
an embodiment.
[0017] FIG. 4 shows an illustration of a circuit in accordance with
an embodiment.
[0018] FIG. 5 shows an illustration of a wireless charger and/or
power receiver integrated into a mobile device battery cover or
back cover in accordance with an embodiment.
[0019] FIG. 6 shows an illustration of a receiver integrated into a
mobile device and/or battery, in accordance with an embodiment.
[0020] FIG. 7 shows an illustration of an inductive charging system
where the receiver coil (top coil and its substrate) is integrated
into or on a rechargeable battery, or into or on a mobile,
electronic, or electric device, in accordance with an
embodiment.
[0021] FIG. 8 shows an illustration of a helical coil and a
representative shape for the generated magnetic flux by this coil,
in accordance with an embodiment.
[0022] FIG. 9 shows an illustration of a coil designed to have an
annular shape with no winding in the middle, in accordance with an
embodiment.
[0023] FIG. 10 shows an illustration of the integration of the wire
wound or PCB or stand-alone coil on a metal layer surrounding the
coil, in accordance with an embodiment.
[0024] FIG. 11 shows an illustration of a metal layer cut at one or
several places to avoid the possibility of creation of circulating
currents in the metal surrounding the coil, in accordance with an
embodiment.
[0025] FIG. 12 shows an illustration of an embodiment wherein a
metal or other thermally conductive layer is used for heat removal
from the coil.
[0026] FIG. 13 shows an illustration of an embodiment including the
use of heat distribution away from the coil with a metal layer
below the coil.
[0027] FIG. 14 shows an illustration of an embodiment which uses
use heat distribution away from the coil with a metal layer below
the coil.
[0028] FIG. 15 illustrates the use of heat distribution away from
the coil with a metal layer below the coil, in accordance with an
embodiment.
[0029] FIG. 16 illustrates the use of heat distribution away from
the coil with a metal layer below the coil, in accordance with an
embodiment.
[0030] FIG. 17 illustrates the placement of a material between the
substrate for the antenna coil (marked IC card, IC tag) for the NFC
or RFID card and a metal backing material such as a battery case or
in case the RFID is attached to a metallic material, in accordance
with an embodiment.
[0031] FIG. 18 is an illustration of several geometries.
[0032] FIG. 19 illustrates a charger and receiver for inductive
wireless power transmission with magnetic layer shielding and
annular magnet outside of the magnet shield layer area, in
accordance with an embodiment.
[0033] FIG. 20 shows an illustration of a design for integration of
a wireless charger and/or power receiver into a mobile device
battery cover or back cover, in accordance with an embodiment.
[0034] FIG. 21 shows an illustration of another embodiment, in
which the inductive coil and receiver is integrated into or on a
battery.
[0035] FIG. 22 shows an illustration of another embodiment, in
which the receiver circuit is integrated in the inside or outside
of the device back or battery door.
[0036] FIG. 23 illustrates an embodiment including a wireless
inductive charger and Inductive receiver coil and circuit.
[0037] FIG. 24 is an illustration of another embodiment for
enabling charging of cylindrical batteries.
[0038] FIG. 25 is an illustration of another embodiment , in which
the charger can include multiple coils for charging several
batteries at the same time
[0039] FIG. 26 is an illustration of another embodiment, including
a wireless charger and/or power supply is in the form of a small
device that includes a USB connector and directly connects to the
side of a laptop to form a platform area where a phone, camera, or
other mobile device or battery can be placed and can receive power
to operate and/or charge.
[0040] FIG. 27 illustrates an embodiment for mobile devices such as
a mobile phone, MP3 or video player, game station, laptop, tablet
computer, book reader, Computer or video or TV display, etc, a
wireless charger and/or power supply is integrated into a stand or
holder for such a mobile device so that the mobile device can be
powered or charged when placed on the stand.
[0041] FIG. 28 illustrates a further embodiment of a charger/power
stand which could in addition incorporate an area for
charging/powering a keyboard and/or a mouse and/or joystick or
remote control and/or other mobile devices such as mobile phone,
MP3 player, camera, game player, remote control, battery.
[0042] FIG. 29 illustrates embodiments wherein a skin or case for a
mobile phone includes a rechargeable battery and connector for the
mobile phone.
[0043] FIG. 30 illustrates a removable or fixed receiver coil and
electronics that can fit into a slot to allow the notebook computer
to be wirelessly charged from below the notebook computer, in
accordance with an embodiment.
[0044] FIG. 31 illustrates a wireless charger and/or power supply,
in accordance with an embodiment.
[0045] FIG. 32 illustrates another embodiment where the wireless
receiver coil and/or electronics are housed in a device attached to
the bottom of a notebook computer through a connector that exists
in many laptops for docking.
[0046] FIG. 33 illustrates a configuration for the circuitry which
can be included in common Li-Ion batteries.
[0047] FIG. 34 illustrates a battery that may contain specialized
circuitry to provide battery ID or authentication.
[0048] FIG. 35 illustrates a wireless charging receiver, in
accordance with an embodiment.
[0049] FIG. 36 illustrates an implementation of a case or battery
door for a mobile device such as a mobile phone, in accordance with
an embodiment.
[0050] FIG. 37 illustrates a receiver coil and circuit integrated
into a mobile phone battery, in accordance with an embodiment.
[0051] FIG. 38 is an illustration of a wirelessly chargeable
battery pack that may include one or more battery cells, battery
protection and/or ID circuit and/or temperature sensors such as
thermistors, in accordance with an embodiment.
[0052] FIG. 39 illustrates the flow of current (in dashed lines)
when the mobile device is plugged into an external wired charger
and or charger/data cable and another device such as a notebook or
desktop computer, in accordance with an embodiment.
[0053] FIGS. 40 and 41 illustrate implementations of a wireless
chargeable battery for mobile devices, in accordance with an
embodiment.
[0054] FIG. 42 illustrates a side view of the battery with various
layers of the receiver coil, optional heat, electromagnetic shield
and/or optional alignment magnet or magnets shown, in accordance
with an embodiment.
[0055] FIG. 43 is an illustration of a case where an alignment disk
magnet is incorporated into the center of a coil in a manner not to
increase the overall thickness of the receiver coil/shield
layer/magnet stack, in accordance with an embodiment.
[0056] FIGS. 44 and 45 illustrate other implementations with
annular or ring or arc alignment magnets whereby the magnet is on
the outside of the receiver coil and the coil and/or the
electromagnetic/heat shield layers can fit inside the ring or
annular or arc magnets between the coil and the battery cell, in
accordance with an embodiment.
[0057] FIG. 46 illustrates an embodiment wherein a metal layer with
discontinuous portions is placed behind and/or around the coil.
[0058] FIG. 47 is an illustration of an embodiment where the heat
transfer layer is implemented on the same layer as the coil or is
constructed not to overlap the coil structure.
DETAILED DESCRIPTION:
[0059] With the proliferation of mobile devices in recent years,
the area of powering and charging these devices has attracted more
attention. The vast majority of the electronic devices in use today
are powered and/or charged through conduction of electricity
through wires from a power supply or charger to the device. While
this method has proven to be efficient for most stationary devices,
recently, there has been an interest in providing wireless methods
for powering or charging one or several mobile devices, batteries,
or electronics devices. The advantages include the ability to
eliminate a charger and/or power supply cord and the possibility of
implementing a universal charger/power supply that can be able to
charge/power multiple devices one at a time or simultaneously. The
so called "wireless power" methods can also be generally divided
into conductive and inductive methods. While the conductive methods
use flow of current from a charger into the mobile devices and/or
battery to provide power and therefore are not strictly speaking
wireless, they offer geometries where a user can place a device on
a pad or similar object and receive power through matching contacts
on the back of a device or an after market cover or `skin` and the
pad without `plugging in` the device. Methods based on an array of
connectors or strips of metal in a pad that can power mobile
devices conductively have been proposed.
[0060] The inductive methods utilize coils or wires near the
surface of a charger and/or power supply to create a magnetic field
in the vicinity of the surface. A coil or wire in a receiver
embedded into a device that is in the vicinity of the surface can
sense the magnetic field. Power from the charger can be transferred
to the receiver without any wired connection through air or other
media in between. By using a higher Quality Factor (Q) resonant
circuit, the distance between a wireless charger and/or power
supply and receiver coil has been where, in general, larger
distances are achieved at the expense of efficiency increased.
These so called magnetic resonance techniques for wireless power
transfer are a variation on the inductive power transfer and will
be considered in that category in the discussion here.
[0061] The inductive method has several advantages over the
conductive approach, such as: [0062] Connectors that are a major
failure point in electronics are eliminated. [0063] Environmentally
hermetic devices can be developed that are immune to moisture or
liquids. [0064] The receiver can be built directly on the battery
so the battery can be charged through the outside shell of the
device by induction. This enables changing the battery of any
existing product after-market with a similar sized and shaped
battery to enable inductive charging. [0065] With a properly
designed charger and/or power supply pad, the charging/powering is
independent of position and does not require placement of device in
any particular location or orientation.
[0066] As described herein, powering or charging of a mobile or
electronic device or battery may be used interchangeably. Many
mobile devices incorporate rechargeable batteries and require
external DC power to charge these batteries for operation. However,
in case of some devices such as a computer laptop, while the device
is connected to DC power to charge its internal battery, the device
may also be using the DC power to operate simultaneously. The ratio
of power used for charging the internal rechargeable battery to
operating the device depends on the degree to which the battery is
discharged, the power necessary to operate the device, and what the
device is doing at any given time. In the extreme, a laptop with
its battery removed may only use the DC power to operate. In this
case no charging occurs and 100% of the provided DC power is used
to operate the device.
[0067] Contextually Aware Inductive Charger/Receiver
[0068] In accordance with some embodiments described herein,
various methods are described by which the wired and/or wireless
power devices and chargers or power supplies can provide additional
connectivity and communications capabilities. In this way, in
addition to charging, during the charging or docking process, other
activities that are useful to the user can be implemented. While
most of the description below is based on wired and/or the
inductive method, the embodiments described here can be implemented
with traditional wired charging and/or power and wireless charging
and/or power through the inductive method or the conductive method
or the magnetic resonance method, optical, or other methods for
power transfer some of which have been described above. Inductive
methods of power transfer are described below as an example of the
more general wireless power transfer.
[0069] With the proliferation of the wireless charging and/or power
and communications technologies, many new embodiments of products
and services can be implemented that can provide user convenience.
Especially, the combination of wireless power and wireless
communications technologies provides a seamless convenient user
experience that is very attractive in the mobile environment. In
this embodiment, several architectures and methods for combining
charging/power transfer with data/signal communication to provide
additional functionality and use cases that are `contextually
aware` are described. By contextually aware charging or power and
communication, we mean that the mobile device or the charging
platform adapts to the location or use model of interest to the
user and environment and provides different functionalities,
applications and features depending on preset or ad hoc
conditions.
[0070] FIG. 1 is a high level view of a mobile device and/or
battery in communication with a host device that is also being
powered and/or charged. The host device may be a charging pad or
docking station, or can be a laptop, kiosk, car, train, airplane,
computer, data gateway, set top box, game station, speakers, video
monitor, music or video system, a piece of furniture such as a
desk, chair, etc. The mobile device and/or the host can itself be
connected to the Personal Area Network (PAN), Local Area Network
(LAN), Wide Area Network (WAN), Metropolitan Area Network (MAN),
Satellite, or cellular networks (3G, 4G, GSM, Edge, etc.) or
specific navigation or other networks through wired methods,
wireless methods, fiber optics, DSL, WiMAX, WiFi, dial up modem,
etc. Also the host and the mobile device can communicate through a
variety of wired or wireless methods such as USB, Bluetooth, WiFi,
WiMAX, Wireless USB, etc. The means for the charging and/or
powering of the mobile device and/or the host can be wired (through
an AC/DC adaptor, USB or mini-usb connector, etc.) or wireless
(through induction, conduction, magnetic resonance techniques,
microwave, optical, solar cells, etc.). In the figure, only a
subset of potential protocols and methods for connectivity and
communication and charging/power have been shown but the extension
to other protocols including specific protocols for control of
devices in the home and/or car or other specific situations is
clear for the persons in the field.
[0071] In FIG. 1, as an example, the basic components of an
inductive wireless charging system are shown. In accordance with an
embodiment, the system comprises the power paths and power control
signals shown in solid lines. Data lines are in dashed lines.
Double dashed lines represent connections that can be data or
charger and/or power supply signals. The charger and/or power
supply comprises a drive circuit for exciting the charger coil.
This can be a field effect transistor (FET) or other transistor for
generating the alternating current to drive the coil. The
regulation/communication and control section is responsible for
controlling the frequency/pulse duration, or other characteristics
of the drive to control the transferred power or to communicate a
signal or data to the receiver. In addition, the circuit can
contain a sense circuit that is used to sense the proximity of the
receiver and/or as a component for data or signal transfer between
the charger and/or power supply and the receiver. In the general
geometry shown in FIG. 1, the regulation/communication and control
portion or a separate circuit can also provide a communication
channel for data to and from a host device such as a laptop or
other mobile device or an environment such as a car or other
vehicle or home or office computer or other device where the
charger/power supply is located or is connected to or nearby. By
being near each other, we mean that 2 devices are within a distance
such that they can interact through a wireless, wired, optical, or
other method or protocol within a Personal Area Network (PAN) or
Local Area Network (LAN). The mobile device and/or the host can
contain additional communication systems such as Bluetooth, WiFi,
WiMAX, Wireless USB, Zigbee, NFC, GPS, or wired communications such
as USB, Ethernet, DSL, Modem, Fiber optics, Optical, HDMI, Power
Line Communication (PLC), or other protocols for communications and
control between devices and internet or systems such as in the
house, car, etc. The charging and/or power for the mobile device
may be through induction, conduction, resonant magnetic power
transfer, optical power, etc. and/or traditional wired
technologies.
[0072] In the description provided herein, data is defined as
information or file or signals that are exchanged that are not
necessarily directly involved in the charging/power supply
operation. Another example of information being exchanged between
components for charging/power supply function is charger signal
(CS). Examples of data can be name, address, phone number, or
calendar information, music, video, TV, podcasts, or image files or
application files. In addition data can be information related to
amount of charge in a battery, presence of a mobile device on a
charger, type of device being charged, information about the user
of the mobile device and their preferences, location or status of
the mobile device, battery, charger or host, etc. In FIG. 1, the
data lines have been shown in dotted line while the solid lines
represent connections for charging function. Some connections such
as the one from the sense circuit to the regulation, communication
and control can be for data or charging signal depending on whether
any data exchange is implemented or the sense circuit is strictly
used for charger and/or power supply signal functions. Similarly,
for example, the connection from the mobile device to the
regulation, communication, and control circuit in the receiver can
be either for data or charger and/or power supply signal. These
signals are shown with double dotted lines in FIG. 1. The breakdown
between CS and data shown is as an example and many other
situations where the signals may be interpreted as belonging to
either group may occur.
[0073] In FIG. 1, a general schematic which can include
bi-directional data and CS transfer is shown. However, the flow of
information can be uni-directional as well. In this case, for
example, if the CS and data is from receiver to charger and/or
power supply, only a sense circuit in the charger and/or power
supply may be implemented. In the block diagram shown in FIG. 1,
the data from the charger and/or power supply to the receiver can
be transferred by low or high frequency modulation of the amplitude
of the power signal (the drive signal for power transfer) or
frequency modulation and filtering or synching in the receiver.
These techniques are often used in communication circuits and can
be applied here. Data or CS information can be transferred from
receiver to charger and/or power supply by techniques such as
modulating the load impedance of the receiver, or other techniques,
as described for example in U.S. Patent Application titled "SYSTEM
AND METHOD FOR INDUCTIVE CHARGING OF PORTABLE DEVICES", application
Ser. No. 12/116,876, filed May 7, 2008, (published as U.S. Patent
Publication No. 20090096413), which is incorporated by reference
herein. In this way, any data or CS in the receiver appears as a
change in the load of the charger and/or power supply output and
can be sensed by the charger and/or power supply sense circuitry.
The data exchanged between the charger and/or power supply and the
receiver can be exchanged in analog or digital format and many
options for this exchange exist.
[0074] In accordance with other embodiments, it is possible to have
the data and/or charge signal data transferred through another
mechanism separate from the power signal. In the embodiment shown
in FIG. 2, a wireless channel for data and CS is shown where the
wireless channel can be a dedicated special channel between the
charger and/or power supply and the receiver or can be based on an
existing protocol such as Bluetooth, WiFi, WiMAX, Wireless USB,
Zigbee, NFC, etc. or a custom or proprietary protocol.
[0075] FIG. 2 shows a wired and/or wireless charger and/or power
supply and receiver architecture with a separate wireless
connection for data and/or charger and/or power supply signal
information. In accordance with another embodiment, it is also
possible for this channel to be through another set of coils.
[0076] FIG. 3 shows a wired and/or wireless charger and/or power
supply and receiver architecture with a separate inductive
connection for data and/or charger and/or power supply signal
information in accordance with another embodiment. In FIG. 3, the
CS and/or data is communicated through a second set of coils that
may be separate from the power transfer set of coils. The two sets
of coils can be physically separate or be wound wires or PCB coils
that are manufactured to be flat or curved and be on the same plane
or close to each other. The different coils for power and CS and/or
data in FIG. 3 can be operated at different frequencies to avoid
interference or be at the same frequency but physically separated
to provide isolation.
[0077] FIG. 4 shows a wired and/or wireless charger and/or power
supply and receiver architecture with a separate optical
transceiver or opto-coupler for data and/or charger and/or power
signal information in accordance with an embodiment. In FIG. 4, the
CS and/or data is communicated through an optical transceiver or
opto-coupler comprising an optical source such as LED or laser,
etc. and detector. The transceivers can be physically separate from
the coils or can occupy the same space for space saving and/or
alignment. For example, they can be placed at the center of flat
coils.
[0078] In accordance with an embodiment, the receiver shown in
FIGS. 1-4 can be built into or on a mobile device such as a mobile
phone, MP3 player, camera, GPS device, Bluetooth headset, laptop,
speakers, video monitors, stereo systems, mobile storage device,
etc. The receiver may be integrated into or on a device or battery
or into or on a factory or after- market mobile device battery
cover or outside sleeve or skin or carrier for the device and/or
battery. In the case that the receiver can be integrated in or on a
mobile device battery cover or a skin or case, sufficient
electrical connections between the mobile device battery cover or
back or a skin or a case and the mobile device for carrying power
and any charging signal and/or data should be implemented. For
example, in FIG. 1, the partition between the parts integrated into
or on a mobile device battery cover or back or a skin or case and
inside the mobile device can be along any of the lines shown.
[0079] FIG. 5 shows a design for integration of a wireless charger
and/or power receiver into a mobile device battery cover or back
cover in accordance with an embodiment. The battery can also be
powered/charged by conventional wired connection from an AC/DC
adaptor or USB or mini USB connector, etc. The circuitry after the
receiver coil shown in FIGS. 1-4 can be partitioned into a part on
the back cover or mobile device battery cover and a section
integrated into the mobile device and/or the battery. The two parts
transfer power/signal/data with electrical connectors/pins in the
mobile device back cover or battery cover and corresponding mating
ones in the mobile device and/or battery. The mobile device in this
case may also be charged/powered by a wired charger/USB cable
connection. It may be desirable from a mechanical and size point of
view to have the minimum amount of parts of the receiver on the
mobile device battery cover or a skin or a case (such as only the
receiver coil) and the rest of the circuit may reside inside the
mobile device. On the other hand, for signal integrity purposes and
for lower noise levels, it may be desirable to have many of the
parts near the receiver coil and the resulting dc voltage and any
other data lines to be connected to the mobile device. Thus the
connection between the mobile device battery cover or back or a
skin or a case and the rest of the mobile device and/or battery may
comprise 1 or 2 to many connector pins that may carry power and/or
charging signals and/or data including information about battery
temperature, battery verification, etc. This is somewhat atypical
of mobile device battery covers or covers or skins or cases for
mobile devices currently used which are typically passive parts
made of plastic, metal, or leather, etc., and have no electrical
functionality.
[0080] In FIG. 5, in accordance with an embodiment, the receiver
coil and/or receiver circuit section can also include additional
electromagnetic shield layers such as absorbers and/or metal layers
and/or ferrite layers and/or heat spreading/and/or heat shield
layers to provide better performance and reliability.
[0081] In addition, to align the receiver coil with the charger
and/or power supply coil, one or a number of magnets can be used.
These magnets can be placed on or around the coil and mounted to be
aligned and attract corresponding ones in the charger and/or power
supply to align the coils laterally to allow maximum efficiency and
power transfer. As an example, in FIG. 5, a ring magnet is shown on
or around the receiver coil. This ring magnet can be magnetized
perpendicular to the plane and can attract a corresponding and
similar magnet in or around the charger and/or power supply coil to
align the two parts. In FIG. 5, an optional gap or break in the
ring is also shown. This gap can serve to limit or eliminate the
eddy currents generated in the magnet due to the time varying
magnetic field of the charger and/or power supply coil or receiver
coil, and has been found experimentally to be quite effective in
eliminating wasted power and heating of the magnet due to the eddy
current effect. The ring magnet is shown as an example and other
magnet geometries or other methods for alignment can be used for
alignment of the coils. These may include straight magnets, arc
magnets, square magnets, or one or more magnetic discs or other
shapes attached to the receiver coil or mobile device battery cover
or back of the device, skin, case, etc. and similarly incorporated
in the charger and/or power supply. The magnets may be mounted such
that they allow rotation of the receiver coil and thus the mobile
device and/or battery with respect to the charger and/or power
supply while maintaining charging capability. Use of the magnets is
especially beneficial in cases where the charger and/or power
supply is integrated or attached to a moving platform such as in a
car where it is important to keep the mobile device stationary
while the car is moving.
[0082] In order for a mobile device battery cover or back of a
device to have the connectivity to the mobile device and/or battery
required, the cover or back may use pins or connectors that can
mate with corresponding ones in the mobile device or directly on to
the battery of the mobile device. These pins may be of the type
that connect when the two parts are slid against each other or make
an electrical connection when pressed together or alike.
[0083] Inside the mobile device, the power and charging signal or
data from the connector pins are carried to the rest of the
charging/regulation/charge or power management circuit or IC and
may also be connected to the main processor or other circuitry
inside the mobile device to provide or receive data or other
information. In the example geometry shown in FIG. 4, power from
the power management IC (PMIC) inside the mobile device is applied
to the battery connectors and used to charge the battery.
[0084] FIG. 6 shows a receiver integrated into a mobile device
and/or battery which has the capability to be charged wirelessly or
by traditional wired power from an AC/DC adaptor or power supply
and/or USB, or another device or other means.
[0085] If the mobile device has both means of wireless and wired
charging/powering of the mobile device and/or battery as shown in
FIG. 1-6 above, the power from the wired connector may be connected
to the same battery charger or PMIC in the mobile device and/or the
battery and the PMIC or the mobile device or the regulation, or
separate switching circuitry. The communication and control circuit
may have an algorithm for deciding which one to over-ride if power
is simultaneously available from wired and wireless sources.
Switches in the path of power from either or both sources may cut
off or reduce power from each power source. In addition, the
receiver may provide signaling to the wired charger and/or power
supply and/or wireless charger and/or power supply circuit to shut
down so only one source of power to the mobile device and/or
battery is operating and providing power. Similarly, this signaling
path can provide additional signals to combine power or other
functions if needed. Other methods for enabling or disabling
charging from either source are possible and should be implemented
to avoid any issues in simultaneous charging from two sources.
[0086] Additional connections can provide information on the
validity and type of battery, Identification verification, its
temperature, state of health, amount of charge or other
information. These data can also be shown on the mobile device
screen or activate an LED or audible signal or alike through the
interface with the main processor in the mobile device or other
circuitry.
[0087] As an example, in a mobile phone, the amount of charge of
the battery and whether it is being charged wirelessly or in a
wired manner may be indicated on the main phone display.
[0088] In the above example, the power from the receiver and any
additional data and/or charging signals are carried through
connectors between the battery cover/back cover and the mobile
device. It is also possible to have the connector directly on the
battery in the device and the receiver can connect to it in a
similar way. The circuitry of the receiver necessary to charge the
battery and/or perform any CS or data communication and any
possible alignment magnets and heat or EMI shield layers can be
partially placed on the back cover and partially on or in the
battery as appropriate.
[0089] In accordance with an embodiment, when the mobile device or
battery is placed on or close to the wireless charger and/or power
supply, the charger and/or power supply and the mobile device or
battery may exchange a code or verification and charging or
transfer of power commences. The mobile device and/or battery can
also check to see if simultaneously power is being received from
the wired power connection and decide which one to accept or even
to in some circumstances to accept power from both sources to
charge faster. The charging process may then in turn activate other
functions directly or through the main processor in the mobile
device or the host or nearby devices or devices connected through
the internet or other communication methods such as wireless 3G,
GSM, WiMAX, etc. There may also be LEDs, indicators, etc. in the
cover or back or case or skin or mobile device display screen or in
the charger and/or power supply and/or host device where the
charger and/or power supply is included or connected to (car,
train, laptop computer, other mobile device storage device, kiosk,
clothing, or briefcase, purse, etc.) or audible signals to provide
further information to the user.
[0090] In accordance with an embodiment, the data or CS exchanged
between various devices can: Show start of charging and/or end of
charge; Show battery temperature; Show state and level of battery
charge indicator; Communicate data to and from mobile device;
Communicate device presence to charger and/or power supply (or
device that the charger and/or power supply is built into or
connected to such as laptop) or nearby devices or devices connected
by internet or other communication methods; Communicate type of
charger and/or power supply/environment (wired/or wireless charging
and/or power) and from what device (being charged and/or powered
from laptop, car, etc.); Communicate device battery status/state of
charge, etc. to charger and/or power supply or device charger
and/or power supply is built into or connected to such as laptop or
nearby devices or devices connected by internet or other
communication methods; Charge and/or power mobile device wirelessly
at a different rate or speed depending on the charging platform and
location/type; Perform synchronization or download or upload of
data. Synchronization or upload or download can include calendar,
contacts, to do lists, new downloaded programs, pictures, movies,
music, other data, files, date, time, etc.; Show a list of
movies/video/music/pictures that are available on the device. etc.
on host device or nearby devices or devices over the internet or
WAN connection; Verify a mobile device user identity or credit
card, ATM, or other financial information; Charge or bill user for
services such as charging or powering and/or other services such as
use of internet, phone or video calls or download or upload of
data, movies, music, ringtones, pictures, or computer or mobile
applications or services or online purchases, etc.; Show battery
charge/status on mobile device or host a nearby devices or devices
connected by internet or other communication methods; Show amount
of memory used or free on mobile device on host or nearby devices
or devices connected by internet or other communication methods;
Show any tasks to be accomplished or emails received or calendar
items that the device has received on a host or nearby devices or
connected by internet or other communication methods; Connect the
mobile device and host so the memory in either one is seen as a
directory on the other one and is accessible; Enable access to the
files and directory of the mobile device over the internet or by
nearby devices; Duplicate the mobile device screen on the host, a
nearby device, or laptop or nearby devices or devices connected by
internet or other communication methods; Use the broadband or other
connection of host or a nearby device to provide communication for
the mobile device or vice versa; Use Power Line communication from
host and/or mobile device to provide communication for to each
other or to other nearby devices or other devices or servers over
the internet, etc.; Use the mobile device as a remote controller
for the charger and/or power supply or the host or a nearby device
or devices connected by internet or other communication method; Use
the charger and/or power supply host or a nearby device or devices
connected by internet or other communication methods as a remote
controller or interface for the mobile device being charged or
powered; Use the mobile device to change temperature, lighting,
shades, etc. in a home, office, or car environment; and/or any
combination of the above.
[0091] In addition, the charging of the mobile device can activate
a number of functions in the mobile device and or the host or
charger and/or power supply or nearby devices or devices connected
by internet or other communication method. For example, assume a
mobile smart phone/MP3 player/camera such as an iPhone or a
Blackberry phone is being charged on a wireless and/or wired
charger and/or power supply. Recognizing that the mobile device is
being charged, the device can, for example: Indicate the wireless
or wired charging on its screen; Activate Bluetooth transmitter so
that calls coming in can be connected to a Bluetooth headset
without picking up the phone from the charger and/or power supply;
Activate the speaker phone when calls come in; Rotate the images on
the phone according to how the phone is placed on the Charger
and/or power supply to allow easy viewing; and/or Activate WiFi,
Bluetooth, Wireless USB or WiMAX connectivity to connect wirelessly
to a nearby computer, data gateway, kiosk, or laptop to transfer or
sync data/images/video/music/files/calendars/phone book, etc.
[0092] Exchanging a code and/or data between the charger and/or
power supply and the mobile device, the two parts can recognize
each other and take actions that may be pre-programmed by the
manufacturer or programmable by the user or can depend on other
factors such as day/time/location of charging/priority list, etc.
This "Contextually Aware" charging may have many uses and can
reconfigure the mobile device or the host (laptop, car, kiosk,
other mobile device, etc.) or nearby devices to act differently
depending on ID received from charger and/or power supply and/or
mobile device.
[0093] For example, a mobile device can be programmed to recognize
a charger and/or power supply at home or office and act differently
in each situation and configure itself to connect to a variety of
devices at home or office through appropriate wireless or wired
connections such as Bluetooth, WiFi, WiMAX, Wireless USB, etc.
depending on the preferred characteristics and options for the
charger and/or power supply and even connect with the home or
office's computer or stereo or video entertainment systems to: Log
on and authenticate user in the office or home environment when
entering into each area and charging on the appropriate charger
and/or power supply commences; Automatically log on to the
appropriate WiFi/Wireless USB network; Connect and play music
through home or office stereo or nearby speakers; Play movies, etc.
through home video system; Synch with computer/download/upload
content/music/video, etc.; Act as a wireless modem for connectivity
of computers or cell phones nearby; Become the wireless modem for a
home Voice Over IP (VOIP) system; Place the phone on mute in case
of a call or ring louder or use a different ring tone, etc.;
Transfer all incoming calls to the home or office (depending on
location) landline or VOIP phone automatically; Connect phone with
wired broadband Home WiFi system so calls or Data received or sent
go through the wired WiFi system and the wired Broadband network.
This may provide more clear calls or save on calling charges or
provide faster download or upload of Data and files; Initiate or
activate incoming or outgoing Video calls through the mobile phone
connection (GSM, 3G, WiMAX, etc.) using external home or computer
screen or TV and external speakers and microphone; Route incoming
or outgoing Video calls through the home or office WiFi/WiMAX and
or fixed DSL, Fiber or other communication system; Duplicate the
phone's screen or functions on a home computer so it can be
controlled from another location. Users may be able to access music
or pictures and play/stop/shuffle from a nearby computer or other
mobile device or make outgoing calls or control other functions.
The functions available may also depend on the mobile device being
charged and the range of functions/software interface may change
based on the device. For example, with a smartphone with many
available functions, the interface can have many available options
while for a simple phone, these can be more limited; Activate a
Bluetooth headset or external or internal speaker and microphone if
a call comes in; and/or Use the charger and/or power supply host or
a device nearby or laptop to dial the phone number on the mobile
phone.
[0094] Similarly, in a car environment, identification of the
mobile device on a charger and/or power supply in a car can:
Activate the mobile device to connect to car Bluetooth system
automatically so incoming calls are connected to speakerphone or
car speakers and a microphone if call comes in or initiated by user
to allow hands free driving; Connect the mobile device to car
entertainment system wirelessly to: Play music or movies in car;
Play different films for different people in car; Play different
music to different Bluetooth headsets; Allow watching TV, podcasts,
etc. received through the mobile device; Route video calls to in
car video system; Have the mobile device synchronize and download
or upload music or other information to storage device in car for
entertainment or diagnostics; Enable mobile device to notify
emergency crew in case of accident or emergency; Start GPS view or
program on the mobile device, etc.; and/or Allow the phone to be
the broadband modem that can then connect to other mobile devices
within car with Bluetooth or WiFi, wireless USB, etc. and
authenticate with these devices.
[0095] Also, the mobile device presence and wired or wireless
charging can trigger a series of reconfigurations in the car, such
as: Set the temperature to pre-programmed mobile user desired
level.; Set the car seat to the right position for the mobile
device user; Adjust mirrors to the right position for mobile device
user; Turn on the radio/stereo to specific favorite station/music;
Change driving conditions of car (performance/speed vs. comfort,
etc.); Can automatically switch the control for various features on
phone to controls available in car or on steering wheel or a remote
controller to: Dial phone numbers, Turn volume up/down on voice or
video calls or music or video/TV, Switch music/movie, Fast
forward/back/stop, pause, playback, etc.; and/or if charger and/or
power supply is at an angle or different locations, through either
recognition between device and charger and/or power supply/or
through accelerometer, change device display
orientation/function.
[0096] In other settings, the authentication can trigger other
pre-programmed functions. For example in public chargers and/or
power supplies, the verification of the presence of mobile device
on a charger and/or power supply can trigger connection to public
WiFi or WiMAX systems or on a public charging kiosks, can
authenticate the user and allow download or upload of movies,
pictures, music, etc. and even provide method for billing and
charging of the customer for services used.
[0097] One will note that many of the functions above (watching TV
using the mobile device as a receiver, GPS, etc.) and connectivity
through WiFi, etc. are quite power hungry and without the
simultaneous charging or powering of the mobile device occurring,
cannot be sustained for a long period. As another example,
downloading or uploading pictures or videos from a camera or mobile
phone, etc. may take a very long time and drain the battery without
simultaneous charging or powering of the mobile device/camera
occurring.
[0098] In addition, in accordance with various embodiments the
charger and/or power supply and the mobile device may have the
following characteristics: Charger and/or power supply pad or stand
has one or more magnets to align with similar magnets in or around
the receiver to align the coils and to keep the device in place;
Charger and/or power supply or stand that is tilted so the user can
view the device screen better when device is placed on the charger
and/or power supply pad or stand; The charger and/or power supply
or pad that has a non slip surface to allow better grip of mobile
device when it is placed on the pad or stand; and/or the charger
and/or power supply pad or stand that has an adhesive, magnetic,
nonslip, or surface with suction cup on the back so it can be
attached at an angle, vertically, or horizontally on a surface.
[0099] Improvements in Thermal Performance and Efficiency
[0100] In accordance with some embodiments described herein,
features can be provided that overcome several shortcomings of
previous approaches, including methods by which the wireless power
devices and chargers or power supplies can provide better thermal
performance, better detection of external objects, and better power
transfer efficiencies, and can enable operation at greater distance
between charger and receiver coils.
[0101] While most of the description below is based on the
inductive method, the embodiments described here can be implemented
with either the inductive method or the magnetic resonance method
for power transfer some of which have been described above.
Inductive methods of power transfer are described below as an
example of the more general wireless power transfer.
[0102] There are several issues that are important in design of a
practical wireless charging system. The charger and receiver for
the wireless charger system include wound wire coils, PCB or
flexible PCB coils, or stamped or etched free-standing coils or
deposited on a substrate. The coils create and detect the AC
magnetic field that is used for power transfer and
communication.
[0103] As described in "Coreless Printed Circuit Board (PCB)
Transformers--Fundamental Characteristics and Application
Potential", Ron Hui, S. C. Tang, H. Chung, Vol. 11, P. 3, 2000), a
magnetic flux pattern can be generated when, e.g. a 1 cm diameter
coil is excited at 8 MHz. When viewed in the horizontal cross
section or plane of the coil, the pattern shows the high
concentration of the magnetic flux at the center decreasing to
towards the edge. The resistive heating of the coil due to current
and the high amount of the flux at the center and any associated
generated eddy currents create a hot spot at the center.
[0104] Experimentally, the inventors have found that for a 10 turn
4 Oz. Copper PCB coil on a 0.2 mm FR4 PCB backing with 32 mm
outside coil diameter and Inside diameter of 1 mm, operating with
0.5 mm spacing between the Charger and Receiver coils and 2.5 W
output power at 5 V (0.5 A). Without any thermal management, the
center of the coil can be 20 degrees over room temperature due to
resistive heating of the coil. The situation is exacerbated by the
fact that this center will be a hot spot where heat is generated
within a small surface area and cannot dissipate laterally or
vertically due to low thermal conductivity FR4 substrate.
[0105] While the increase in temperature is not too high for many
applications, it is desirable to improve this especially for the
receiver that is placed inside or on a mobile device or battery.
The lifetime and reliability of a battery depends on its operating
temperature and lower operating temperatures are highly
preferred.
[0106] U.S. Patent Publication No. 20090096413, which is
incorporated herein by reference, describes use of several methods
for reducing this temperature rise. Two methods described therein
involve use of a thermal conductive layer attached or incorporated
near the receiver and/or charger coils to rapidly spread or
dissipate any generated heat. An example of such a material can be
high heat conductivity ceramic material. In addition, we have
described the use of metal layers around the coil that will further
rapidly conduct any heat away from the coil and spread over a
larger surface area to dissipate through convection or heat sinking
in other ways. These methods can of course be combined to further
reduce any effect.
[0107] Experimentally, the inventors have found that attachment of
a 0.25 or 0.5 mm thick ceramic layer to the charger and receiver
coil in the configuration above reduced the maximum temperature
rise at the center of the coil to 6 to 14.degree. C. depending on
whether there was additional air gap between the coils and the
power transferred. Addition of high conductivity layers to the
coils, however, can increase their thickness and also increase the
manufacturing complexity of the parts which is not desirable
especially inside mobile devices or batteries. In an embodiment,
two other methods are provided for reducing this temperature
increase without increasing the thickness and cost or complexity of
the parts.
[0108] Another aspect of an embodiment of the invention herein
deals with foreign object detection. If a metal object such as a
coin is placed on the charger coil, the charger can begin to heat
the object to very high degrees that can cause burn for the user or
failure of the device.
[0109] The inductive coils can carry one or more amps. For example.
U.S. Patent Publication No. 20080164839 describes the thermal
performance of coils with foreign objects on the surface of the
charger. In this example, it was found that with wire wound helical
coils and a metal object such as a coin placed on the charger, the
surface temperature of the charger coil can reach 150.degree. C.
and higher at the center within 90 seconds. Different locations on
the coil experience different temperature increases. In this
example, temperature detection sensors were placed behind the
charger coil and monitored this temperature to detect foreign
objects and to ensure that unsafe temperatures were not reached.
75.degree. C. was chosen as the threshold and used to cut off power
to the charger coil. While this strategy is practical, it is best
to avoid any power being delivered to the foreign object
altogether.
[0110] As disclosed herein, a method is described so that, in
accordance with some embodiments, power would not be delivered in
such circumstances. Another feature of some embodiments are methods
for achieving higher power transfer efficiencies and distances
between the coils.
[0111] Recently, by using a higher Quality Factor (Q) resonance
circuit, the distance between a wireless charger and receiver has
been increased, as described, for example, in U.S. Patent
Publication Nos. 20090015075 and 20090033564, and in "Efficient
wireless non-radiative mid-range energy transfer" Aristeidis
Karalis, John D. Joannopoulos, and Marin Soljacic. Annals of
Physics Vol. 323, p.34, (2008). In general, larger distances are
achieved at the expense of efficiency. The above references
describe a geometry for a magnetic resonance system where a charger
coil loop is used to excite a high Q coil and capacitor resonant
antenna that get excited by the charger coil loop and emit RF power
in resonance with a receiver resonant antenna that couples power to
a Receiver coil loop and to a load. This geometry allows larger
coil to coil distance for operation.
[0112] However, some of the drawbacks of the geometry are that: a)
The voltage in the LC resonant antenna can reach over 1000 V
according to the inventors. This is a high voltage and requires
large components that are especially not desirable in the receiver;
b) The system has relatively low efficiencies of 30% or lower or
even 10%; c) Since the distance between the coils can be several cm
and possibility of human exposure to the field exists, the maximum
magnetic field for such a device in use is limited by regulatory
limits on safe exposure limits; d) Due to the larger travel
distance of the fields in this geometry, the magnetic fields extend
beyond the receiver when integrated into a mobile device or battery
and can affect the performance of the mobile device or battery. In
addition, any metal layer or wires in this area can affect the
operation. Ideally, one would prefer the fields not to extend
beyond the receiver coil.
[0113] As disclosed herein, in accordance with an embodiment,
methods are provided for using resonance to achieve larger
operating distance between the coils while overcoming some of the
issues with geometry described above.
[0114] FIG. 7 shows an inductive charging system where the receiver
coil (top coil and its substrate) is integrated into or on a
rechargeable battery (FIG. 7a) or into or on a mobile, electronic,
or electric device (FIG. 7b). In these configurations, the coil can
be a wound wire coil or a Printed Circuit Board (PCB) coil.
[0115] In the configurations shown in FIG. 7, the magnetic field
generated by the bottom charger coil may extend beyond the coil on
the top and interfere with the operation and performance of the
battery or the device. In addition, any metal layer in the
packaging of the battery cell or in the mobile device may affect
the field pattern and magnitude. The time varying magnetic field
can also set up eddy currents in metal layers or wires and can
cause excessive voltages or heat generation. In addition the coils
may generate heat during transfer of power due to the current in
the windings and the heat may have undesirable effects on the
battery or the device electronics. As disclosed herein, methods are
described to improve the power transfer efficiency, effect of metal
layers nearby, and thermal and Electromagnetic Interference issues
related to design of Inductive and resonant magnetic wireless
chargers.
[0116] FIG. 8 shows a helical coil and a representative shape for
the generated magnetic flux by this coil. The temperature
distribution would similarly have a peak at the center. This is
caused by the higher Flux at this point as well as the geometric
situation where a high heat build up at the center would be
radiating outward to spread in the plane of the coil and would
create a hot spot at the center. To address the issue of thermal
heat build up at the center of the coils, two methods are discussed
here. In the first method, the coil is designed so that it does not
terminate at the center of the circle. FIG. 8 shows a helical coil
pattern where a peak at the center of the coil for magnetic flux
exists. The resulting temperature distribution will similarly have
a peak at the center due to this high flux and also due to the
symmetry of the geometry and high heat generation at this center
which will be spreading in 2 dimensions in the plane. The coil is
designed to terminate before reaching the center so the coil has an
annular shape and the magnetic flux (center) does not have a
maximum at the center. The flux does not create a hot spot.
Therefore the resulting temperature profile (right) is lower at the
center and lower overall.
[0117] In accordance with an embodiment, the coil is designed to
have an annular shape with no winding in the middle so that the
magnetic flux is more flat or even lower at the central portion
(see FIG. 9). The central area also has very small length of wire
and therefore contributes little to the inductance of the overall
coil. With an annular shape coil, large amounts of heat are not
generated at the center and the center does not become a peak
temperature area. This design results in a lower overall
temperature for the coil area and a more distributed temperature
profile at the center (see the right figure in FIG. 9).
[0118] The inductance of a helical coil pattern is well
approximated by:
L=r.sup.2N.sup.2/((2r+2.8d).times.10.sup.5)
where r is the mean radius of the coil in meters. For an evenly
distributed helical coil, this is equivalent to (outer radius+inner
radius)/2. d is the inner radius of the coil. d is the depth of
coil in meters which is equivalent to the outer radius minus the
inner radius. N is the number of turns.
[0119] Therefore, for an example, for a 10 turn coil starting at
the center and ending in radius of 16 mm, the calculated inductance
is 1 microhenry which is similar to measured values.
[0120] To design for the same inductance and outer radius, it can
be shown that 7 turns with the inside loop starting at radius of 5
mm would provide a similar inductance.
[0121] Due to more uniform Flux profile and lower and smoother
temperature profile, such an annular shaped coil would be
preferable in practice.
[0122] Therefore, in accordance with an embodiment it is preferred
to use inductive coils that have annular shapes with the center
area without any winding in the center area to reduce the heat
generation there.
[0123] The inventors have earlier shown methods such as use of
metal layers around the coil to further remove heat from the
coil.
[0124] FIG. 10 shows the integration of the wire wound or PCB or
stand-alone coil on a metal layer surrounding the coil to remove
any heat further. The metal layer can be a layer on a PCB and if
the coil is also a PCB coil, the two parts can be made on the same
PCB either on the same layer or different layers to make the
manufacturing simple. In addition, alignment magnets to pull the
charger and receiver coil into alignment can be used. In the right
figure in FIG. 10, integration of electronics and an annular
alignment magnet is shown on the same PCB board to allow further
simple integration.
[0125] In the configurations shown in FIG. 10, the magnetic field
from the coil may set up unwanted eddy currents in the surrounding
metal layer and shown annular magnet. To overcome these effects,
the annular magnet may be cut or be discontinuous in one or more
places as shown in FIG. 8 on the right to prevent the carriers to
circulate around the ring due to the magnetic field and create
unwanted loss and heating.
[0126] Similarly, the metal layer can be cut at one or several
places to avoid the possibility of creation of circulating currents
in the metal surrounding the coil. This is shown in FIG. 11.
Experimentally, it is found that placing some cuts in this layer
and any alignment magnet such as the annular one shown prevents
undesirable eddy currents and associated heating of the metal
layer.
[0127] However, it is still important to distribute the heat
generated in the coil laterally efficiently to avoid local hot spot
formation and heating at the coil. In accordance with an embodiment
a method for efficient heat distribution from the coil is provided,
without the undesirable effects of eddy currents.
[0128] FIG. 12 shows an embodiment wherein a metal or other
thermally conductive layer is used for heat removal from the coil.
In this configuration, the metal layer that is under the coil layer
has a pattern that has diametrical cuts that prevent circular
movement of carriers and therefore reduce eddy currents. Other
patterns can also be used. In this case, for PCB coils, the coil
pattern and the metal pattern can be on different layers with a
thin layer of PCB material such as FR4, Polyimide, or other
dielectric in between to create electrical isolation. Ideally, the
layers would be separated with a dielectric material that has high
thermal conductivity and low electrical conductivity. The heat that
is pulled away and distributed from the coil can be further
distributed laterally by other metal layers such as in FIG. 8
around the coil or by combining this with dielectric or ceramic
layer, etc. or other heat sinking methods.
[0129] FIG. 13 illustrates the use of heat distribution away from
the coil with a metal layer below the coil. The left figure shows
an annular coil layer, the center figure shows the heat
distribution metal layer. On the right, the metal layer on the coil
layer is shown. The 2 layers typically would have a thin
electrically non-conductive layer in between. This can be easily
created in PCB production by having the coil layer and the metal
layer in different layers of a PCB. To avoid eddy current
generation, the metal layer is discontinuous so carriers cannot
complete a circular motion round the center of the coil. In this
example, diametrical cuts in the metal layer prevent the circular
motion of carriers while the metal layer effectively distributes
heat away from the center to the edges where it can be dissipated
by convection or conduction or other methods.
[0130] In the other embodiments as shown in FIG. 13, the annular
coil pattern can be combined with the discontinuous metal layer to
further reduce any thermal effects.
[0131] FIG. 14 illustrates the use heat distribution away from the
coil with a metal layer below the coil. The figure shows the heat
distribution metal layer. To avoid eddy current generation, the
metal layer is discontinuous so carriers cannot complete a circular
motion round the center of the coil. In this example, diametrical
cuts in the metal layer prevent the circular motion of carriers.
Additional circular cuts further reduce the area that could
potentially create eddy currents. The metal layer effectively
distributes heat away from the center to the edges where it can be
dissipated by convection or conduction or other methods.
[0132] In FIG. 14, another embodiment is shown where further
circular cuts in the metal layer reduce any possible eddy currents
further compared to geometries in FIGS. 12 and 13.
[0133] In any of these geometries, the heat would have to cross the
area between the metal layers that is discontinuous. This
transmission could occur through the substrate material such as PCB
that the metal layer is attached to, a ceramic layer or other layer
that may be electrically nonconductive.
[0134] FIG. 15 illustrates the use of heat distribution away from
the coil with a metal layer below the coil. The figure shows the
heat distribution metal layer. To avoid eddy current generation,
the metal layer is discontinuous so carriers cannot complete a
circular motion round the center of the coil. In this example,
diametrical cuts in the metal layer prevent the circular motion of
carriers. Additional circular cuts further reduce the area that
could potentially create eddy currents. To bridge the thermally
resistive gap in the metal layer that would affect effective heat
transmission, a second metal layer that is electrically separated
from the first heat transmission layer can also be incorporated.
This layer can have metal layers that cover the gaps in the first
metal layer so it can bridge the thermal gap effectively. If the
thickness of dielectric layer between the metal layers is thinner
than the gap in the pattern in the metal layer, this technique
could be quite effective in bridging the thermal gap. The metal
layers effectively distribute heat away from the center to the
edges where it can be dissipated by convection or conduction or
other methods.
[0135] For the thermal dissipation layers shown here, the minimum
gap between sections are given by the limits of the PCB process
used. It may be important to electrically isolate the sections to
avoid eddy current generation. However, this gap in the metal layer
also causes a thermal barrier to effective heat transmission. One
method to improve this is to bridge the thermally resistive gaps
with another metal layer that is fabricated on another layer and
electrically isolated from the first thermal distribution layer. An
example is shown in FIG. 12 where the other layer separated by a
thin dielectric such as used in PCB manufacture bridges the gaps in
the first metal layer to improve thermal distribution.
[0136] The patterns and embodiments shown above are shown as
examples and in practice, a combination of the above methods or
other geometries are used to achieve the goals discussed. The heat
distribution layers shown are also examples and other patterns that
can pull the heat away from the coil without affecting or minimally
affecting the performance of the charger can be used.
[0137] An additional benefit of the methods described here is that
the magnetic field generated by the coil will not extend beyond the
metal layer and will therefore not affect any electronics or other
metals beyond this. This can be important in the design of the
charger and the integration of the receiver into a battery, mobile
device, or its skin, carrier, battery compartment cover, etc. This
technique also reduces extraneous EMI generation.
[0138] FIG. 16 illustrates the use of heat distribution away from
the coil with a metal layer below the coil. The figure shows the
heat distribution metal layer as slices in a circle pattern. The
helical coil for inductive power transfer is also shown. To avoid
eddy current generation, the metal layer is discontinuous so
carriers cannot complete a circular motion round the center of the
coil. In this example, diametrical cuts in the metal layer prevent
the circular motion of carriers. The metal layer is extended beyond
the coil to provide removal of heat further from the heat
generating coil.
[0139] FIG. 16 shows that the metal layer in heat removal can be
extended beyond the inductive coil pattern so the heat is pulled
away from this center and then can be dissipated away through
conduction or convection in contact with other thermally conductive
layers. These could include ceramic, polymer, plastic, or even
metal layers if attached to the metal layer appropriately to reduce
any eddy current effects or can simply be through convection of air
in contact with the large surface area of the metal.
[0140] The extended metallic layer patterns shown in FIGS. 12-16
can be applied to any coil geometry shown above and combined with
other ideas and geometries presented here to further reduce any
heating or EMI effects.
[0141] A method for reducing the EM fields behind the coil to
minimize interference with an electronic device operation or any
metal layers in a mobile device or a battery is to use a magnetic
material in between a coil such as a receiver coil and any metal
directly behind the coil. Use of such materials is common with Near
Field Communication (NFC) or Felica receivers in mobile devices. An
example is FSF-200 material sold by Maruwa Corporation which is
designed to have a high permeability with both a real and imaginary
part.
[0142] In accordance with an embodiment, an appropriate material
for use as a shield is FSF200 from Maruwa Corp. which is designed
for shielding of Near Field Communication (NFC) or RFID tags that
are in contact with a metal backing. The material has high real and
significant imaginary (loss component) permeability at the
operating frequency of 13.6 MHz. FIG. 17 shows the placement of
this material between the substrate for the antenna coil (marked IC
card, IC tag) for the NFC or RFID card and a metal backing material
such as a battery case or in case the RFID is attached to a
metallic material.
[0143] In this case, the material has large .mu.' (real part of
permeability) and significant .mu.'' (imaginary part of
permeability--related to loss) at the operating frequency of 13.6
MHz. Therefore the magnetic field is highly concentrated in the
magnetic sheet that is also lossy. In this way, use of a thin layer
of magnetic shield of 1 mm to 0.2 mm and below significantly
reduces the effect of the metal behind the receiver or antenna coil
in this example. Depending on the characteristics needed, one can
also engineer material that only have significant real permeability
values without being lossy at the region of interest to allow
strong guidance and focusing of the magnetic field without
suffering loss. This may be useful for achieving higher inductances
and efficiencies in certain designs. For example, for the FSF200
material shown in FIG. 17, operation at lower frequencies such as 1
MHz would allow concentration of magnetic field in the magnetic
shield without the loss component. As mentioned above, these
material can be engineered to have the desired .mu.' and .mu.''
values at desired thicknesses to optimize efficiency and shielding
necessary.
[0144] It is clear from the above description that the use of such
magnetic material in combination with metal layers described above
can provide better thermal and electromagnetic performance.
[0145] FIG. 18 shows several geometries discussed above. In FIG.
18a, the basic coil structure is shown. In FIG. 18b, the use of
magnetic layers to shield the areas above and below the coils form
the magnetic field is demonstrated. FIG. 18c shows use of a heat
spreader layer that could be non electrically conductive such as
ceramic or a metal layer designed to minimize eddy current effects
such as the method outlined in FIGS. 12-16 and other similar
embodiments. FIG. 18d shows how magnetic layers and metal shields
can be combined to provide thermal and electrical shielding. Other
combinations of structures are also possible that for example
combine metal and ceramic layers to conduct heat and/or provide
electromagnetic shielding. The choice of the geometry would be
dictated by space, cost, weight, design characteristics, desired
thermal and electrical performance and other criteria.
[0146] In any of the geometries discussed here, use of alignment
magnets such as shown in FIGS. 10 and 11 or other geometries are
compatible with the geometries for improved thermal and
electromagnetic interference performance and even when magnetic
layers are used, the magnets can be placed outside of the area
covered by magnetic layers and therefore not be affected by
them.
[0147] FIG. 19 illustrates a charger and receiver for inductive
wireless power transmission with magnetic layer shielding and
annular magnet outside of the magnet shield layer area.
[0148] In FIG. 19, use of a magnetic shield with an annular magnet
is shown as an example. Note that the magnet is not covered by the
magnetic layer and can provide alignment pull to align the charger
and coil magnets while the magnetic layer provides shielding of the
areas above and below the top and bottom coils (respectively) to
reduce electromagnetic interference and/or to enhance power
transfer efficiency. The top view and side view are shown in FIGS.
19a and 19b.
[0149] Other geometries shown above can be combined with magnets to
provide the desired temperature and shielding behavior while
providing alignment of the coils with the magnets.
[0150] Improvements in Charging Devices and/or Batteries
[0151] In accordance with some embodiments described herein, a
wireless charger system or system for transfer of power wirelessly
can be provided in several different geometries and/or modes.
[0152] In accordance with an embodiment, the Receiver in the mobile
device or battery to be charged inductively can be integrated by
the manufacturer in to the device, an example of which is shown in
FIG. 20. FIG. 20 shows a design for integration of a wireless
charger and/or power Receiver into a mobile device battery cover or
back cover in accordance with an embodiment. The battery can also
be powered/charged by conventional wired connection from an AC/DC
adaptor or USB or mini USB connector, etc. The circuitry after the
receiver coil shown can be partitioned into a part on the back
cover or mobile device battery cover and a section integrated into
the mobile device and/or the battery. The two parts transfer
power/signal/data with electrical connectors/pins in the mobile
device back cover or battery cover and corresponding mating ones in
the mobile device and/or battery. The mobile device in this case
can also be charged/powered by a wired charger/USB cable
connection.
[0153] It may be desirable from a mechanical and size point of view
to have the minimum amount of parts of the receiver on the mobile
device battery cover or a skin or a case (such as only the receiver
coil) and the rest of the circuit can reside inside the mobile
device. On the other hand, for signal integrity purposes and for
lower noise levels, it may be desirable to have many of the parts
near the receiver coil and the resulting dc voltage and any other
data lines to be connected to the mobile device. Thus the
connection between the mobile device battery cover or back or a
skin or a case and the rest of the mobile device and/or battery can
comprise 1 or 2 to many connector pins that can carry power and/or
charging signals and/or data including information about battery
temperature, battery verification, etc. This is somewhat atypical
of mobile device battery covers or covers or skins or cases for
mobile devices currently used which are typically passive parts
made of plastic, metal, or leather, etc. and have no electrical
functionality.
[0154] In FIG. 20, in accordance with an embodiment, the receiver
coil and/or receiver circuit section can also include additional
electromagnetic shield layers such as absorbers and/or metal layers
and/or ferrite layers and/or heat spreading/and/or heat shield
layers to provide better performance and reliability.
[0155] In addition, to align the receiver coil with the charger
and/or power supply coil, one or a number of magnets can be used.
These magnets can be placed on or around the coil and mounted to be
aligned and attract corresponding ones in the charger and/or power
supply to align the coils laterally to allow maximum efficiency and
power transfer. As an example, in FIG. 20, a ring magnet is shown
on or around the receiver coil. This ring magnet can be magnetized
perpendicular to the plane and would attract a corresponding and
similar magnet in or around the charger and/or power supply coil to
align the two parts. In FIG. 20, an optional gap or break in the
ring is also shown. This gap can serve to limit or eliminate the
eddy currents generated in the magnet due to the time varying
magnetic field of the charger and/or power supply coil or receiver
coil and has been found experimentally to be quite effective in
eliminating wasted power and heating of the magnet due to the eddy
current effect. The ring magnet is shown as an example and other
magnet geometries or other methods for alignment can be used for
alignment of the coils. These may include straight magnets, arc
magnets, square magnets, or one or more magnetic discs or other
shapes attached to the receiver coil or mobile device battery cover
or back of the device, skin, case, etc. and similarly incorporated
in the charger and/or power supply. The magnets can be mounted such
that they allow rotation of the receiver coil and thus the mobile
device and/or battery with respect to the charger and/or power
supply while maintaining charging capability. Use of the magnets is
especially beneficial in cases where the charger and/or power
supply is integrated or attached to a moving platform such as in a
car where it is important to keep the mobile device stationary
while the car is moving.
[0156] In order for a mobile device battery cover or back of a
device to have the connectivity to the mobile device and/or battery
required, the cover or back can use pins or connectors that mate
with corresponding ones in the mobile device or directly on to the
battery of the mobile device. These pins can be of the type that
connect when the two parts are slid against each other or make an
electrical connection when pressed together or alike.
[0157] Inside the mobile device, the power and charging signal or
data from the connector pins are carried to the rest of the
charging/regulation/charge or power management circuit or IC and
may also be connected to the main processor or other circuitry
inside the mobile device to provide or receive data or other
information. In the example geometry shown in FIG. 21, power from
the power management IC (pmic) inside the mobile device is applied
to the battery connectors and used to charge the battery.
[0158] In accordance with another embodiment shown in FIG. 21, the
inductive Coil and Receiver is integrated into or on a battery. In
this case, the battery can be charged directly when placed on the
charger or placed inside the device behind a battery cover or door.
One or more alignment magnets can also be integrated into or on the
battery to help in alignment of the Receiver coil with a
corresponding charger coil in the charger. In the case shown, a
round magnet is shown that allows alignment of the charger and
battery while the two parts are at any rotational angle with
respect to each other. The magnet can be one piece or multiple
pieces and can include a gap to avoid heating created by the
magnetic field of the inductive charger. The battery in this case
can be an after-market or original manufacturer battery that would
allow wireless inductive charging. The battery contacts make
contact with corresponding contact points in the device to power
the device and/or provide other charging or communication
information. The contact can for example provide information on the
battery temperature, whether it is charged wirelessly or by wired
power, state of battery, data communication, or other information.
Such a battery can also be charged through conventional wired
charger or power supplies through these connectors. The receiver
circuit inside or on the battery can also include switches so the
battery would switch between wired and wireless charging paths and
can also signal the charger to shut off if a wired charger for the
battery (through battery contacts) is present.
[0159] In accordance with embodiments the receiver can communicate
non-charging data (communication such as contact list, calendar or
other information) with the charger base. In these cases, the data
can be transferred to the device being charged through other
connectors on the battery with appropriate corresponding connectors
in the device.
[0160] The battery and/or the charger can in addition include
layers for heat spreading, dissipation or thermal or
electromagnetic barriers or layers to increase the efficiency or
other feature of the system. These layers can be metallic, ceramic,
magnetic, plastic, conductive layers, etc. that have appropriate
properties for achieving performance improvements. The coil in this
embodiment can be flat or curved and/or multi-layered and created
on a Printed Circuit Board (PCB) or Flexible PCB, or be stamped or
cut from a metal or other type of material film or formed or
manufactured in the appropriate shape and be free-standing (no
backing). The coil can be integrated inside or on the outside or
surface of the battery pack.
[0161] It may also be desirable for the wireless charger to include
additional capabilities. For example, the wireless receiver circuit
(in or on the battery in this embodiment) can include WiFi
capabilities that the device itself lacks. If the battery can
communicate with the device through provisioned connector points,
then it is capable of enabling the device to communicate wirelessly
through WiFi.
[0162] Another example is that of a mobile phone that has Bluetooth
capability but not WiFi. In accordance with embodiments the battery
can have appropriate circuitry to communicate with external devices
wirelessly through WiFi and transfer the data to the mobile device
through Bluetooth. In this way, the wireless receiver can provide a
transmission protocol translation to enable seamless communication
between the mobile device and other devices or networks or the
charger. Implementation of such additional features is possible in
each of the implementations discussed here.
[0163] In accordance with an embodiment, the charger shown in FIG.
21 can be powered through an external power source such as an AC or
DC supply or can itself include a one-time use or rechargeable
battery or other methods such as solar cells or fuel cells or hand
crank, etc. to provide power to it. The charger can also include
one or more status indicators that show power being applied to the
charger, charging occurring, and charge complete or other
features.
[0164] In accordance with another embodiment, shown in FIG. 22, the
receiver coil and/or the receiver circuit is integrated in the
inside or outside of the device back or battery door. The receiver
coil and/or the circuit can also be integrated into the device back
or battery door during production and be for example inside the
injection molded battery door part. In this embodiment, the power
and/or data received by the receiver circuit can be routed to the
input power and/or data connector of the device through wires that
would terminate in a connector or similar part. The user can enable
the device to charge wirelessly by snapping the cover or battery
door in place and plugging the connector into the device connector
plug. Similar to above embodiments, the receiver circuit and coil
can include additional layers of material to reduce electromagnetic
interference, heat, or other undesired effects.
[0165] There are several issues that are important in design of a
practical wireless charging system. The charger and receiver for
the wireless charger system include wound wire coils, PCB or
flexible PCB coils, or stamped or etched free-standing coils or
deposited on a substrate. The coils create and detect the AC
magnetic field that is used for power transfer and
communication.
[0166] In addition, the connector for the mobile device can, as an
option, include an additional connector to allow wired connection
of a wired charger and/or wired communication. For example for a
device with a female Universal Serial Bus (USB) connector, the
connector can have a male USB connector to plug into the device
connector to provide power and/or communication to the device and a
female USB or other connector on the other side or nearby to enable
a cable to be plugged in to charge or power the device wirelessly
or to communicate with the device without removing the cable from
the device. The receiver circuit and/or the connector may include
appropriate switching circuits to switch between wired and wireless
charging or power. The receiver circuit and/or the external
connector may also enable other functions such as data connectivity
through additional protocols (WiFi, WiMax, NFC, Bluetooth, Wireless
USB, etc.) or provide communication protocol translation (Bluetooth
to WiFi, etc.) or provide additional functionality (AM, FM or
satellite radio tuner or transmitter, TV tuner, data storage on
additional memory, expanded processing capability, flashlight, bar
code scanner, laser display, extra battery power, GPS, external
speaker, microphone, etc.) that is desirable by user. As such the
receiver circuit can include additional antennas and/or
transmitters and/or receivers.
[0167] In accordance with embodiments, the receiver coil and/or
circuit can be inside, outside or in a layer (inside an injection
molded part for example) of a cover or door or skin of the device.
It can also be integrated into an external skin or protective cover
for a material such as Neoprene, plastic, leather, cloth or other
material covering a device.
[0168] In accordance with another embodiment, the receiver and/or
the coil are attachable or stick-on parts that are attached or
stuck on the outside or inside of the device cover or battery door
and routed to the connector. Such an embodiment can allow the same
receiver coil and/or circuit to be used for multiple devices
without the need to integrate into model specific back covers or
battery doors. With a thin receiver coil and circuit or a small
circuit placed inside the connector plug, such a receiver may be
0.1 mm or thinner and not add much to the device thickness and may
be attached to the inside or outside of the cover or battery door
with adhesive or other methods.
[0169] FIG. 23 illustrates a wireless inductive charger and
inductive receiver coil and circuit. In this case, the receiver
and/or the receiver circuit are attached to the battery surface and
routed and connected to the battery contacts with attachable wires
or cable. In accordance with the embodiment shown in FIG. 23, the
receiver coil and/or the receiver circuit are attachable or
stick-on parts that are directly attached the battery exterior and
the charging power for the battery is routed and connected to the
battery terminals with attachable wires or connectors that make
electrical contact with these connectors through pressure or
electrically conductive adhesive. The receiver can include magnets
for alignment between the receiver and the charger coil and other
layers for thermal or electromagnetic properties as described
above. In addition, the attachable circuit on the battery may
provide additional communication or other capabilities as described
above. This method allows any manufactured battery to be changed to
recharge wirelessly. The required battery voltage for typical
batteries and/or maximum capacity or other requirements are
pre-programmed into the receiver circuit eliminating the need for
any change by the user. For example, a large number of mobile
device batteries use single cell Li-Ion batteries that require a
specific charging routine that charges the battery to a maximum of
4.2 V. The receive circuit can have this algorithm pre-programmed
or contain a charger IC with a Li-Ion charger to enable any single
cell Li-Ion battery to be recharged and can be used by a variety of
battery sizes and capacities.
[0170] Such a method for enabling wireless charging of batteries
can also be applied to batteries with round or other shapes. For
example NiMH or NiCd or Li-Ion batteries in AA, AAA, C, D, or 9 V
size can be enabled to charge wirelessly with stick on thin
chargers shown above. In the case of round body batteries, the
receiver coil can be manufactured in a curved shape to be able to
attached or incorporated into or on the body of the battery.
Another method for enabling charging of cylindrical batteries is
shown in FIG. 24.
[0171] In accordance with the embodiment shown in FIG. 24 for
cylindrical batteries, the Receiver coil can be integrated into one
of the end terminals of the battery and the receiver circuit can be
placed inside the body of the battery (shown at bottom in this
case) and internally connected to the battery terminals to charge
the battery. Placement of the battery vertically with the coil in
proximity to a corresponding active charger coil can transfer power
to the receiver circuit and charge the battery. In this geometry,
the center of the receiver coil can be connected to a metal contact
which serves as the negative terminal of the battery.
[0172] As shown in FIG. 25, in accordance with an embodiment the
charger can include multiple coils for charging several batteries
at the same time and may contain a variety of methods for alignment
of batteries and the coils such as magnets (FIG. 25a) or mechanical
methods such as slots or tubes for batteries to fit in (FIG. 25b)
for alignment of charger coil and receiver coils of the
battery.
[0173] Additional Uses and Implementations of Inductive
Charging
[0174] In accordance with some embodiments described herein, a
device is described by which the wireless charger and/or power
supply is a device that is powered by a power source from another
device such as the power available from the USB or PCMCIA port or
similar from a laptop computer or a peripheral hub or consumer
electronic or communication device such as a music player, TV,
video player, stereo, or car stereo USB or other outlets which
include power. The charger can also be incorporated directly into a
battery so that a battery can charge another battery wirelessly.
While most of the description below is based on the inductive
method, the embodiments described here can be implemented with
either the inductive method or the conductive method or the
magnetic resonance method, optical, or other methods for power
transfer some of which have been described above. Inductive methods
of power transfer are described below as an example of the more
general wireless power transfer.
[0175] In one embodiment of this approach shown in FIG. 26, a
wireless charger and/or power supply is in the form of a small
device that includes a USB connector and directly connects to the
side of a laptop to form a platform area where a phone, camera, or
other mobile device or battery can be placed and can receive power
to operate and/or charge.
[0176] In one implementation, in order to provide a compact device,
the USB connector for the wireless charger and/or power supply can
be folded into the device and can be unfolded during use for
plugging into the power source. In another implementation, the
source of the power is the PCMCIA slot in a computer or other
device and the wireless charger has a connector that can slide into
the PCMCIA slot and connect to provide power to the wireless
charger or power supply.
[0177] In a further embodiment to any of the above implementations,
the wireless charger and/or power supply further includes an
internal battery so that while it is plugged into an external
device for power, the internal battery is being charged. The
wireless charger or power supply can simultaneously be able to
charge or power a mobile device placed on or near its surface
wirelessly. However, furthermore, the user can disconnect the
device from the power from the device by for example disconnecting
it from the USB connector of the laptop and use the wireless
charger away from any power source by operating it from its own
internal battery power. In this way, a self-powered portable,
convenient wireless charger or power supply is implemented. In one
embodiment for a PCMCIA port, the charger and/or power supply with
its own internal battery is small and thin enough to fit into a
PCMCIA slot and is generally stored and carried in the slot and
when wireless charging or powering of a mobile device is needed,
the wireless charger and/or power supply is ejected from the PCMCIA
slot and the internal battery in the device is used to power the
charger and/or power supply to charge a mobile device and/or
battery. In another embodiment, a wireless charger is imbedded in a
battery so that it can charge another battery wirelessly. The first
battery may itself further include a wireless receiver so that it
can be charged wirelessly. The second battery being charged may be
of lower, similar or higher capacity than the first. In any of the
embodiments described above, the charger and/or power supply can be
designed to charge one or more devices simultaneously.
[0178] In a further embodiment, while a mobile device is placed on
the wireless charger and/or power supply, the commencement of
charging and or powering simultaneously starts a communication
mechanism in the device powering the charger and/or power supply to
exchange data/synchronize or communicate through a wireless method
or through the port providing power to the charger and/or power
supply. Examples of wireless methods of synchronization can include
Bluetooth, WiFi, Wireless USB, Zigbee, optical methods, etc. For
example by placing a mobile phone on the wireless charger and/or
power supply connected to a laptop's USB port, the wireless charger
signals the laptop to begin synchronization and the synchronization
program on the laptop launches and through a Bluetooth or WiFi
connection with the phone, contact lists, calendars, photos, music,
audio files, etc. are synchronized. In another example with a
camera, the photos in the camera are automatically downloaded into
the laptop.
[0179] The wireless charger and/or power supply system can also
include means of communication through the wireless charger/power
system. For example for inductive chargers or power supplies,
communication of data through the power transfer coils can be
enabled. In this case, data from and to the mobile device can
transfer to the device providing power to the wireless charger
and/or power supply through the inductive coils and then through
the port interface such as USB, PCMCIA, etc. that is powering the
charger and/or power supply. The files that are transferred can be
user data such as photos, music, audio or video files or contact
lists, calendars, programs, firmware updates, etc. but can also
include information such as level of battery in the mobile device,
diagnostic information, etc. For example, while a mobile phone or
MP3 player is charging or being powered on a wireless charger
and/or power supply pad connected to the USB port of a laptop, the
degree of charge of the device and its amount of memory use,
firmware version, etc. is shown on the laptop screen. In variations
of wireless power systems, the communication method between the
charger and the receiver for signaling and communication and
control and/or regulation of power can be through a wireless,
optical, or even a form of wired communication. In these cases, the
same mechanism can be used for data transfer as described here.
[0180] In an embodiment shown in FIG. 27 for mobile devices such as
a mobile phone, MP3 or video player, game station, laptop, tablet
computer, book reader, computer or video or TV display, etc, a
wireless charger and/or power supply is integrated into a stand or
holder for such a mobile device so that the mobile device can be
powered or charged when placed on the stand. A mechanical or
magnetic mechanism for attachment or holding of the mobile device
or display on such a stand would keep the parts in proximity and
alignment for wireless charging. The Receiver for the wireless
charger can be built into the device by the manufacturer, or
integrated into a skin or case or a battery for the device.
[0181] To use a magnetic method for securing the device on the
charger and/or power supply, one or more magnets can be placed in
the charger and/or power supply and similar magnets or
ferromagnetic material in the device, its skin, or case or battery
can be used to provide an attractive force to align and hold the
device in place.
[0182] An example of a type of magnet that can be used for this
purpose is a ring or arc magnet that will provide minimal or no
effect on performance of a wireless charger while providing secure
and rotationally invariant alignment and holding power. To reduce
or eliminate eddy currents in a ring magnet in inductive chargers
and or power supplies, a break or cut in the circle prevents
creation of circulating currents and is very beneficial. The ring
is used here as an example and other geometries of thin magnets
such as a square, rectangle, triangle, etc. shape can also be
used.
[0183] In many situations, it would be beneficial for the mobile
device and/or display to exchange data/information with the
charger/power supply and or other devices such as mouse, keyboard,
routers, modems, the internet, other displays, speakers, printers,
storage devices, or USB hubs, etc. In these cases, a means for data
exchange between the mobile device and the external devices through
communication through the stand can be implemented. Such a
communication can be through the wireless charger or other
components such as WiFi, Bluetooth, Wireless USB, Powerline, or
Zigbee communication, etc.
[0184] In addition, the wireless charging stand can provide
additional functionalities to the user. For example, by placement
of the mobile device on the charger and/or power supply, the device
is automatically authenticated and connection to various
peripherals and/or internet is enabled. In addition, the content of
the mobile device is replicated on a larger display or the audio is
routed to external speakers or speakers built into the stand.
Depending on the orientation of the device on the display, the
display on the mobile device and/or display can also rotate its
orientation to appear in the correct orientation for the user.
[0185] For mobile device, Notepad, or tablet users, a keyboard
would be of great use in combination with the stand discussed
above. FIG. 28 shows a further embodiment of a charger/power stand
which could in addition incorporate an area for charging/powering a
keyboard and/or a mouse and/or joystick or remote control and/or
other mobile devices such as mobile phone, MP3 player, camera, game
player, remote control, battery, etc. The keyboard and/or mouse can
incorporate a rechargeable battery and the keyboard and/or mouse
can be stored on the corresponding charger surface when not in use
or even during use. Communication between the keyboard and/or the
mouse and one or more of the mobile devices, notepad, tablet or
display can be through one of the established methods such as WiFi,
Bluetooth, Wireless USB, Zigbee, etc. or through a proprietary
method. In addition, the stand can incorporate speakers so music or
audio from one or more of the mobile devices can be played through
them.
[0186] In another embodiment, the wireless receiver for the mobile
device can include further functionalities that enhance the use of
the mobile device. Some examples are given here. In one example, to
enable a mobile device to receive power wirelessly, a case, battery
door, or attachment to the mobile device includes a receiver for
the mobile device and means of providing power to the battery in
the mobile device but also includes a battery itself that is
charged wirelessly simultaneously. When the mobile device and the
receiver are not in the vicinity of the wireless charger and/or
mobile device, the rechargeable battery included with the receiver
is a secondary battery that powers the mobile device or charges the
battery of the mobile device to extend the useful time of use of
the mobile device. An example is shown in FIG. 29 and FIG. 30,
where a skin or case for a mobile phone includes a rechargeable
battery and connector for the mobile phone. When the skin/case is
attached to the phone and the phone and case are placed on a
wireless charger and/or power supply, the mobile phone is charged
but also the battery within the case/skin is charged. Once the
mobile phone and the case/skin is no longer in the vicinity of the
wireless charger, the battery in the skin/case can operate the
mobile phone prior to the internal battery powering the phone or
the case/skin battery can provide power once the internal battery
to the phone is exhausted thereby extending use time. The switch
over between batteries can be automatic or through the intervention
of the user by a physical switch or software on the mobile device.
While a skin/case is shown here, the battery can also be integrated
into a battery door for the mobile device or be connected to the
power port of the mobile device through a cable or alike.
[0187] In any of the embodiments described here, alignment of coils
in an inductive system is important to allow high efficiency and
operation. Use of magnets in the wireless charger and the receiver
can achieve this function without any physical features or
alignment mechanisms. However, some of the mobile devices can have
components such as electronic compasses that may be disturbed by
the use of magnets in the charger and/or receiver. To reduce or
eliminate such an undesired effect, it is important to shield the
mobile device from the magnetic field. This can be achieved by
incorporating faraday shields or one or more layers of shielding
material such as Iron or Nickel or other Ferromagnetic sheets or
ferrite material or special magnetic material such as mu-metal (an
iron/nickel and other material alloy with very high permeability)
or NETIC or Co-NETIC material (from magnetic shield corporation) or
ceramic or nano materials for magnetic shielding into the receiver
skin or case or the mobile device or battery so that the sensitive
components are shielded from stray magnetic field. In the case of
the receiver type shown in FIG. 29, such shielding material can be
placed between the coil and the inner surface of the case. In
addition, the AC magnetic filed generated by the wireless charger
may interfere with other device functionalities and can be shielded
by incorporation or ferrite or nano magnetic material into the back
of the receiver coil. Such a shield for AC magnetic field can be
effective for shielding the DC magnetic field as well. Otherwise,
it may be desirable to incorporate 2 or more different types of
shield layers.
[0188] In another embodiment, the receiver is built into other
devices that enhance the functionality of a mobile device. For
example, external modules, skins, or cases for mobile phones that
add TV watching or reception, Radio reception, magnetic reading,
Bluetooth connectivity, Global Positioning System (GPS), Universal
remote control, Near Field Communication (NFC) or extended storage
or connectivity capabilities exist. Any of these cases or skins or
modules that plug into the power and or connectivity of the mobile
device or phone can include a wireless receiver so that the battery
inside these modules and/or the mobile device or phone can be
charged or powered wirelessly thereby greatly benefiting the
user.
[0189] Additionally, currently, modules for extending the
usefulness of a mobile device as stick on or attachments or
integrated into mobile device skin or case or battery door that
provide additional functionality exist. Some of these modules can
include internal batteries that require charging. Examples include
stick-on or mobile phone case circuitry and antenna that boost a
mobile phone reception or stick on circuits for mobile phones that
includes Near Field Communication (NFC) circuitry and coil for
mobile devices that do not have this capability built in. To
communicate this information to the mobile device, the sticker can
communicate the NFC data to the mobile device in another protocol
such as Bluetooth or WiFi or Wireless USB, etc. thus translating
between the protocols. The sticker can further include a
rechargeable battery for powering the circuitry. In another
implementation described here, the sticker described here can
include a wireless charger receiver and its sticker's rechargeable
battery can be charged or powered by a wireless charger remotely
thus providing long operation life.
[0190] In another implementation, such a reception booster, or NFC
reader/writer, their coil(s) and the WiFi or Bluetooth circuitry
can be integrated into an aftermarket battery for mobile device
that includes a wireless charging receiver. In this way, a mobile
device such as a phone's battery can be replaced with such a
battery to provide wireless charging receiver capability and
extended range or reception and NFC capability together to a phone
user thus providing much more functionality.
[0191] In some embodiments an aftermarket wireless charger or power
supply receiver unit can be provided that includes all the
necessary receiver coil and circuitry for receipt of power in a
thin profile that can be placed on top of a mobile battery and
connects to the battery connectors with wires, flexible circuit
board, or connector cable so that an original battery is enabled to
receive power wirelessly while simultaneously still operating in
its original housing within the battery compartment of the mobile
device. This method can provide wireless power charging for mobile
devices without affecting other characteristics and size/shape of
the device and would be greatly useful. Additional functionality
such as NFC or NFC to Bluetooth or WiFi capability can also be
incorporated into such a battery sticker to provide even more
functionality and can draw power form the mobile device battery for
its operation thereby eliminating the need for another battery to
power the circuit.
[0192] Improvements in Charging Efficiency and Other Features
[0193] In accordance with some embodiments described herein,
features can be provided to improve charging efficiency, usage, and
other features.
[0194] For example, in the implementation shown above in FIG. 26,
in order to provide a compact device, a wireless charger/power
supply is implemented such that it can fit into an area in an
electronic device such as a desktop or notebook computer or
electronic book or similar. Such a charger and/or power supply can
be powered internally by the electronic device. Extending the
charger and/or power supply outward (similar to ejecting a caddy on
a CD-ROM or DVD-ROM player or recorder, can start the operation of
the charger and/or power supply and provide the user a surface for
charging/powering a mobile device and/or battery. In one
embodiment, such a charger and/or power supply can be built for the
size and shape of existing available slots on desktop or notebook
computers or other devices such as PCMCIA slots or storage devices
such as optical drives such as CD-ROM or DVD players and recorders
and use the existing power ports available in connectors for such
devices or have one or more separate connectors specifically for
its own operation. In such an embodiment, the charger and/or power
supply can be integrated with the laptop or notebook computer
software and/or hardware and perform more advanced functions. An
example can be that when a mobile device such as a phone with an
appropriate wireless receiver is placed on such a charger and/or
power supply area, the charging and/or supply of power is started
and in addition, the mobile phone is synchronized with the desktop
or notebook computer and data such as contact lists, calendars,
email, pictures, music, etc. are synchronized. Such a data
communication can be implemented through data exchange in the
charger link such as data communication through the coils in
inductive charging or through another established data
communication protocol such as Bluetooth or WiFi, Zigbee, or
wireless USB, etc.
[0195] In another embodiment, the charger and/or power supply
described above can be removable and/or retractable. As an example,
many mobile devices such as desktop and notebook computers have
slots for removable optical drives such as CD-ROM or DVD players or
recorders. These components can be made removable so the user can
leave them behind when not in use to save weight or they are
constructed such that the slot can be used for multiple purposes.
For example, a slot can be provided in a notebook computer where
the slot can be used with a removable optical drive accessory or be
used for an additional battery to extend the operating time of the
notebook computer. Furthermore, the optical drive typically
includes a caddy that is retractable and with a mechanical or
software eject, can extend a caddy away from the notebook computer
for the user to place a CD-Rom or DVD or similar media in the
caddy. A similar mechanism can be implemented to extend the charger
and/or power supply surface out from the notebook when in use and
to retract into the notebook when not needed. For example, the
device shown in FIG. 26 can include a wireless charger and/or power
supply incorporated into an optical drive slot. Such slots
typically have internal connections that provide connectivity
between the accessory and internal data or power or battery lines
of the notebook computer. Same connectors or other connectors can
be provided for the removable wireless charger and/or power supply
to operate. As described above, such a removable wireless charger
and/or power supply can in addition provide data connectivity or
trigger data connectivity with the desktop or notebook computer and
the mobile device or battery being charged.
[0196] In a further implementation, such a wireless charger and/or
power supply further includes internal batteries and/or data
storage capability so that when the charger and/or power supply is
plugged in or inserted into a desktop or notebook computer, the
internal battery of the charger and/or power supply is charged and
data from the internal storage device is synchronized. The user can
also remove the part from the desktop or notebook computer and
operate the part and charge or provide power to other mobile
devices while operating the charger and/or power supply from its
own internal battery without or with little assistance from other
power sources. This would provide a highly useful portable device
for providing power and/or charging to mobile devices in various
situations.
[0197] In some cases, it is highly desirable for mobile devices
such as notebook computers, etc. to be chargeable wirelessly. To
enable this, in one implementation, an accessory or charger and/or
power supply device that fits into a slot or available space in a
notebook computer or other mobile device is created such that the
charger and/or power supply device includes a receiver coil and the
appropriate receiver electronics to enable the charger and/or power
supply to receive power wirelessly from a charger and/or power
supply outside the device. As an example, for notebook computers, a
receiver coil and receiver electronics can be built into a PCMCIA
or optical drive size and shape so that in the case of a notebook
computer with such a slot, the coil and receiver can be fit into
the notebook and allow it to be charged or powered from a wireless
charger and/or power supply pad or surface under the laptop. The
receiver coil may include appropriate Electromagnetic shielding or
thermal layers to reduce any effect of the electromagnetic field or
heat on any internal components of the notebook computer. The
connectivity between such a wireless charger and or power supply
and the notebook can be provided by provisioned or existing
connectors inside the notebook computer. An example of this can be
a slot provided in a notebook computer that may serve one or more
purposes of operation with an optical drive and/or extended use
battery. A removable or fixed receiver coil and electronics that
would fit into such a slot would allow the notebook computer to be
wirelessly charged from below the notebook computer. Such a
wireless charger and/or power supply is shown in FIG. 31. In one
embodiment, such a charger and/or power supply coil and receiver
can be incorporated into a removable or built in optical drive so
the same slot can provide 2 functions (charging/power receiver and
optical drive). As discussed earlier, similarly, some removable
batteries for such slots exist for some notebooks. The receiver
coil and electronics can be integrated into such a battery to
charge it directly or charge and/or power the notebook
computer.
[0198] It is also possible to combine the wireless charger and/or
power supply receiver and the wireless charger and/or power supply
together in one embodiment so the same device can receive and/or
transmit wireless power. As an example, a device that fits into an
optical drive slot can receive power wirelessly from below but also
have a caddy compartment that can be extended or ejected to allow
for one or more mobile devices to be charged wirelessly while
placed on or near such a charger and/or power supply.
[0199] In any of the embodiments described above, the wireless
charger/power supply and/or the wireless receiver can include
visual and/or audio or other means of notifying the user about
commencement of charging/power, end of charging/power and/or degree
of battery charge or other diagnostic information such as any
faults, over-temperature, etc. This information can be presented on
or near the wireless charger/power supply or receiver or displayed
on the computer screen through the information being transmitted to
the desktop or notebook computer or even transmitted to another
location for display or processing.
[0200] In any of the embodiments described here, alignment of coils
in an inductive system is important to allow high efficiency and
power in operation. Use of one or more magnets in the wireless
charger and the receiver can achieve this function without any
physical features or alignment mechanisms. To use a magnetic method
for securing the device on the charger and/or power supply, one or
more magnets can be placed in the charger and/or power supply and
similar magnets or ferromagnetic material in the device, its skin,
or case or battery can be used to provide an attractive force to
align and hold the device in place.
[0201] An example of a type of magnet that can be used for this
purpose is a ring or arc magnet that will provide minimal or no
effect on performance of a wireless charger while providing secure
and rotationally invariant alignment and holding power. To reduce
or eliminate eddy currents in a ring magnet in inductive chargers
and or power supplies, a break or cut in the circle prevents
creation of circulating currents and is very beneficial. The ring
is used here as an example and other geometries of thin magnets
such as a square, rectangle, triangle, etc. shape can also be
used.
[0202] FIG. 32 shows another embodiment where the wireless receiver
coil and/or electronics are housed in a device (shown as a flat
part in this image) that is attached to the bottom of a notebook
computer through a connector that exists in many laptops for
docking. The connector can also be used to secure the receiver coil
and/or part to the notebook computer. The combination of the
notebook computer and the receiver (attached to each other), can be
placed on a wireless charger surface or device and the received
power is transferred to the notebook through the connector. The
receiver part may also contain rechargeable batteries to increase
the operational run time of the notebook. In addition, other
features or functions such as an optical drive, additional
communication capabilities, speakers, extra processors, means for
cooling the notebook computer, etc. can be included in this part to
provide even more functionality to the user.
[0203] Another implementation for wireless charging in mobile
device comprises incorporating a wireless receiver coil and
associated receiver electronics into a rechargeable battery. This
can be useful for mobile devices so that a device such as mobile
phone, walkie-talkie, cordless phone, camera, MP3 player, notebook
computer, or other electronic device user can replace the existing
battery in a device with a similar battery with built in wireless
receiver and be able to charge/power the mobile device wirelessly.
It may be desirable for the battery to be able to continue the
ability to charge through the internal charger of the device when
the device is plugged into electricity as well. FIG. 33 shows a
typical configuration for the circuitry included in common Li-Ion
batteries. A Li-Ion battery pack typically includes a battery
protection circuit against over-current charge and discharge
comprises typically two back to back FETs. In addition, circuitry
to allow the mobile device such as mobile phone, laptop or notebook
computer etc. to measure the amount of charge in the battery can be
included. The battery is designed to work with the charging and
"gas gauging" circuitry inside the mobile device to
charge/discharge the battery appropriately and to accurately
reflect the state of charge of the battery and remaining power. In
addition, the circuitry inside the battery may contain means of
measuring the battery temperature such as thermistors to ensure
operation within a safe range. The circuitry may contain a
microcontroller unit to measure and influence charging/discharging
behavior.
[0204] In some cases, a battery may contain specialized circuitry
as shown in FIG. 34 to provide battery ID or authentication. The
microcontroller shown here is from Microchip Corporation. Data I/O
line inside the battery pack is connected through battery contacts
to the device and is queried by the device circuitry for
authentication. This authentication can be implemented by device
manufacturer to guarantee battery performance, quality or for
commercial reasons to prevent counterfeiting, etc. A common way to
authenticate a battery and ensure it is from a valid source is with
a challenge/response system. Challenge/response authentication
circuits, also known as identify friend or foe (IFF) circuits. The
system is implemented so that one part of the system, the host
(typically the mobile device), issues a challenge to the other part
of the system, the token (e.g. battery), when the two components
begin to communicate. After the challenge is received, the token
calculates a response and transmits the results back to the host
system. The direction of the challenge and response can be reversed
or even transmitted in both directions. Additionally, either side
of the system can randomly transmit the challenge and response at
varying times to increase the security of the authentication
process.
[0205] A battery may include protection IC and/or battery ID
(authentication) and/or temperature sensor circuitry inside the
battery pack.
[0206] Wireless charging can be used with mobile devices in several
ways. To enable a mobile device to be charged wirelessly, the
wireless charging module can be incorporated into a battery door or
an external case or skin for a device and the wireless receiver can
be designed to provide regulated power to the input power jack of
the mobile device through a power connector integrated into the
case or battery door. In this case, it may be necessary to allow
the user to access the other features available through the same
device connector. For example, a mobile phone may include a USB
connector that is used for charging the mobile device and for data
connectivity. A stand alone charger with a USB connector would use
the power connectors of the USB to provide power to the device. But
the user can also connect the phone to a notebook computer or other
device with a USB cable and be able to exchange
information/synchronize with the notebook computer and at the same
time charge/power the mobile phone.
[0207] To implement the wireless charger case or battery door as
described above, it can be preferable to enable the user to be able
to be able to charge the mobile device wirelessly through
integration of receiver into the case but also allow the user to
access the power/data connector on the mobile device for data
transfer/synchronization or wired charging if desired. An
implementation for this type of wireless charging receiver is shown
in FIG. 35.
[0208] In this implementation, the case or battery door includes a
mobile device connector that mates with mobile devices connector
and provides power and/or data to the mobile device through. The
wireless power received by the wireless charger is regulated in the
receiver and/or charger or a combination of the two and then routed
to the power contacts of the mobile device through a switching
mechanism. The wireless charger case or battery door can also
include a wired connector that can allow the user to plug in a
cable to connect the case to an external wired charger and/or cable
for charging and data connectivity to other mobile device such as
notebook computer. The power lines of this connector can be routed
to the switching mechanism that routes the power to the output
connector of the mobile device skin. The user may in this way be
able to charge/power the mobile device in a wireless manner by
placing the mobile device and the case or battery door on or near a
wireless charger device. The Switch can be implemented such that it
would provide charging/power priority to either the wired or
wireless charger. For example, a user may place the mobile device
and the case or battery door on a wireless charger/power supply and
at the same time, plug the case or battery door into an external
wired charger and/or wired charging/data device such as a notebook
or desktop computer. In this case, it is necessary to provide a
means to resolve the conflict between the two charging paths. The
switching mechanism provides this by allowing one path to have
priority over the other. For example, if the mobile device is
placed on or near the wireless charger and at the same time, the
wired charger/power path is connected to power, the switch can
provide priority to the wired method and route that power to the
connector the mobile device. At the same time, the switch may
provide a signal to the wireless charger receiver to shut off
wireless power through shutting down the wireless receiver and/or
charger. For example, a signal can be sent by the switch to the
wireless receiver and then to the wireless charger to shut down the
charger until the wired charging power is no longer applied.
Alternatively, the switch can be implemented to provide priority to
the wireless charger so that even when both wired and wireless
charging power are present at the switch, the wireless charger
output is routed to the mobile device connector. Alternatively
priority can be given to either wireless or wired method after
determining which one can provide higher current and therefore
faster charging times or some other criteria.
[0209] In addition, the wired connector can also include data lines
that can be routed directly or through a circuit to the mobile
device connector integrated into the case. So that when the case is
connected to external wired power and data, the data lines are
routed to the correct data connections on the case connector. This
would allow synchronization/data transfer between the mobile device
and the device connected to the wired connector (such as notebook
or desktop computer) to occur without the user needing to remove
the mobile device from the case. In the case where the external
wired power and data connector is a Universal Serial Bus (USB)
connector, the data lines correspond to D.sub.+ and D.sub.- lines
of the USB protocol.
[0210] FIG. 36 shows an implementation of such a case or battery
door for a mobile device such a mobile phone. The case or battery
door includes a receiver coil and receiver and switching circuitry.
The output of this circuitry is routed to the case or battery door
connector to mate with the matching connectors on the mobile
device. In this case, the connector is shown as a pass through that
allows the user to connect a wired cable for power/data to the
connector and the data lines can be routed to the appropriate
connector lines on the opposite side where the connector mates with
the mobile device. At the same time, the power lines of the wired
power/data connector are routed to the mobile device connector
through a switching circuit on the receiver circuit or inside the
connector that will function as described above. Furthermore, the
wireless charger case or battery door may incorporate alignment
magnets to align the wireless receiver coil in the case or battery
door with corresponding magnets in the charger. These magnets can
be flat disks at the center of the coils or ring magnets in or
around the coil or multiple magnets inside or outside the coil
area. They may further include features to reduce any effect of a
magnetic field. For example, for ring magnets, the circle can be
disrupted by a cut in the circular shape so that current flow in a
circular pattern due to a pulsing magnetic field (eddy currents) is
disrupted. In addition, the case or battery door may include layers
in the coil or behind it to provide shielding form the magnetic
field or any generated heat to the mobile device or its battery.
Examples can include metal layers incorporated into PCB coil backs,
separate metal layers, ferrite layers, ferrite/plastic compounds,
nanomaterials, or other materials designed for shielding purposes
that can be tailored for this application. In addition, the
receiver circuitry may include thermal sensors (such as
thermistors) at various locations (coil, circuit, etc.) to monitor
the temperature of the receiver and ensure safe operation. The
information from the sensor can be used to shut down the wireless
or wired charger, reduce the current output, and/or provide a
warning or alarm to user or take other actions.
[0211] Another method for integration of wireless receivers into
mobile devices is for device manufacturers to incorporate the
methods described above into the mobile device during manufacture.
In this manner, tighter integration of functionality with device
operation and function can be achieved.
[0212] In another implementation, the wireless receiver coil and/or
circuit can be incorporated into a rechargeable battery that can be
charged directly on the wireless charger or when inserted to a
mobile device when device is placed on or near wireless
charger.
[0213] As an example, FIG. 37 shows the receiver coil and circuit
integrated into a mobile phone battery. When the battery is
inserted into a mobile device and the device is placed on a wired
charger, the battery can receive power wirelessly from the charger.
However, in many cases, it may be necessary to allow the user to
continue charging and or powering the mobile device through wired
methods as well. Similar to the mobile device case/battery door
implementation discussed above, a method to allow both types of
charging is necessary.
[0214] To integrate a wireless charger into a battery for a mobile
device, it may be necessary to enable the battery to charge
wirelessly through its integrated receiver coil and receiver
circuit (including optional charger IC) or through the battery
contacts by the external wired battery charger through mobile
device contacts and optional internal charge management and/or
charge measurement/gauge IC. FIG. 38 shows the block diagram of
major components of such a system.
[0215] As shown in FIG. 38, the wirelessly chargeable battery pack
may include one or more battery cells, battery protection and/or ID
circuit and/or temperature sensors such as thermistors as described
above, a wireless charger coil, wireless charger receiver circuit,
optional battery charger IC (which incorporates an appropriate
battery charging algorithm for the battery cell to provide the
correct charging voltage and/or current during the entire charging
cycle) and or possibly battery gas gauging (to estimate how much
power remains in the battery) and/or appropriate thermal
sensors/circuitry. In addition, the battery pack can include
alignment magnets and/or magnetic and/or thermal shield layers as
discussed above.
[0216] The path for wireless charging current when the battery is
inserted into a mobile device and the device is placed on or near a
wireless charger is shown in FIG. 38 with dashed lines. The
wireless charger receiver circuit may provide power to the optional
charger IC which is in turn connected to a switching circuit.
Alternatively, the receiver circuit may include battery charging
algorithm so that it can directly charge a battery or power the
mobile device. The output of the switch is connected to the battery
cell contacts through an optional battery protection circuit and/or
battery ID circuit. Optionally, the output can be connected to
directly power the mobile device which may include its own charge
management and/or gas gauge and or battery ID circuit. The battery
can be designed such that it would interact with the mobile device
ID detection circuit to verify the battery and also interface
properly with the mobile device charge management and/or gas gauge
and/or temperature sense circuitry.
[0217] FIG. 39 shows the flow of current (in dashed lines) when the
mobile device is plugged into an external wired charger and or
charger/data cable and another device such as a notebook or desktop
computer. The external charger/power supply can provide power to
charge the battery and/or power the mobile device depending on the
state of charge of the battery and/or the design of the internal
charger circuitry of the mobile device. The mobile device charge
management IC shown can include an algorithm and circuitry to
charge the wirelessly chargeable battery through its contacts. In
this case, the switch inside the battery can be designed to route
the optional mobile device charger IC circuit output to charge the
battery as shown. The battery may also contain appropriate
circuitry for battery protection, thermal protection, battery ID,
etc. In case of an over-temperature condition at the battery, the
receiver can take action such as shut down wired or wireless
charger, disconnect input power to the battery, reduce output
current for charging the battery, provide a visual or audible or
signal alarm, or other appropriate actions to ensure safe operation
and charging of battery. The thermal sensor or sensors can be
placed on or near the battery, the wireless charging coil, critical
components of the circuitry, close to the mobile device interface,
etc. or a combination of the above.
[0218] The switch in the battery can be designed to provide
charging priority to the wired or wireless charging method. For
example, if the mobile device and the wirelessly chargeable battery
are placed on or near a wireless charger and the device is plugged
in to a wired charger or wired data/power device such as a desktop
or notebook computer, the switch can be configured to provide
priority to the wired charger and shut off the wireless charger
through a signal to the wireless receiver, charger, or both. In
addition, the wireless charger receiver can signal the charger to
shut off. Alternatively priority can be given to wireless
charger/power supply over the wired charger/power supply or
priority can be given to either method after determining which one
can provide higher current and therefore faster charging times or
some other criteria.
[0219] FIG. 40 and FIG. 41 show implementations of a wireless
chargeable battery for mobile devices as described above. The
battery may include a receiver coil on its top surface (close to
wireless charger when device/battery is placed on or near a
wireless charger), optional alignment magnet or magnets,
electromagnetic and/or heat shield layers, and receiver and/or
battery protection and/or battery ID, and/or switching circuitry.
To minimize the effect on battery capacity of integration of the
circuitry into it, the circuitry can be placed on the thin edge of
a battery such as a mobile phone or other mobile device
battery.
[0220] FIG. 42 shows a side view of the battery with various layers
of the receiver coil, optional heat, electromagnetic shield and/or
optional alignment magnet or magnets shown. To maximize impact of
integration of wireless charging coil and receiver and other
circuitry into the battery pack, it is important to keep the
reduction in battery volume due to these parts to a minimum. It may
be therefore important to use the thinnest receiver coil and
electromagnetic/heat shields. PCB coils with thin base material
(e.g. FR4) or flexible PCB (e.g. polyimide) or free standing copper
coil patterns or wires can be used. This thickness can be 0.2 mm or
below. Metal and/or electromagnetic shielding material with
thicknesses of 0.1 mm or lower may also be used. In addition, if
one or more magnets are used, they may add to the overall thickness
of the stack or they can be arranged such that their thickness does
not add to the overall thickness.
[0221] FIG. 43 shows a case where an alignment disk magnet is
incorporated into the center of a coil in a manner not to increase
the overall thickness of the receiver coil/shield layer/magnet
stack. In this case the wireless charging coil has an outer and
inner radius and does not fill a whole circular shape. The coil
and/or the shield material behind it may therefore be hollow at the
center. It is therefore possible to place a disk or other shape
magnet in the center of the coil so that the thickness of the
magnet fills the void or takes up some of the space in this center
without adding to the overall thickness of the stack. In an
embodiment where the coil is a pcb coil, the center of the pcb may
have a cut out area such as a circular hole or aperture where the
magnet may be placed. The optional electromagnetic and/or heat
shield behind the coil may also have a similar hole or
aperture.
[0222] FIG. 44 and FIG. 45 show other implementations with annular
or ring or arc alignment magnets whereby the magnet is on the
outside of the receiver coil and the coil and/or the
electromagnetic/heat shield layers can fit inside the ring or
annular or arc magnets between the coil and the battery cell. In
this way, the thickness of the various components on top of the
battery do not add to each other and the overall stack thickness is
given by coil plus the electromagnetic and/or heat shield layer or
the magnet thickness whichever is greater. This would allow the
battery to retain maximum capacity density for a given volume. The
ring or annular or arc magnets have the advantage over the central
magnet shown in FIG. 43 because they allow much more alignment
tolerance and can exert an alignment pull force over a larger
lateral area on a corresponding magnet or magnets in a wireless
charger. In addition, by introducing a gap or cut in the
circumference of a ring magnet so that it is not fully continuous
or by use of one or more arc magnets, any potential eddy currents
in the magnet induced due to the alternating magnetic field of the
wireless charger are reduced or eliminated thereby greatly
increasing the effectiveness of these types of magnets for coil
alignment purposes. The corresponding alignment magnet in the
charger can be a ring, cut ring, or arc magnet and can provide
rotational invariance when the receiver magnet and the charger
magnet are aligned. An arc magnet in the receiver can be used with
a ring or cut ring magnet in the charger or vice versa and will
allow full rotational positioning between the charger and
receiver.
[0223] In any of the implementations above, management of the
generated heat and thermal issues are important. To reduce the
effect of heat generation from the coils, it may be desirable to
increase the thickness of the copper layer used in a PCB or use
thicker wires in wound coils. For the case of PCB coils, in
addition, it is possible to create multi-layer PCB coils such that
several layers of PCB coils are connected in parallel and produce a
resistance that is lower than a single layer thus reducing
resistive heating.
[0224] In addition, heat transfer layers can be incorporated to
spread the heat generated. Such layers need to be designed not to
interfere with the operation of the coils. Since alternating
magnetic fields are generated and detected in an inductive system,
use of a metal layer behind the coil would produce eddy currents
and loss. One method for providing thermal conductivity with metal
layers is shown in FIG. 46 where a metal layer with discontinuous
portions is placed behind and/or around the coil. In this case, the
metal layer comprises rectangular slices that can conduct heat away
from the center of a coil while due to discontinuity between the
slices, the electrons cannot flow in a circular motion due to the
alternating magnetic field. The pattern described here has a number
of triangular slices but any other pattern which can provide heat
transport but does not allow carriers to circulate in a rotational
pattern due to the alternating magnetic field can be implemented.
In FIG. 46, a coil with an inner radius of zero is shown. The coil
may have a non-zero inner radius thus leaving a central portion
that has no coil pattern. This may reduce thermal and/or eddy
current effects on the coil and be preferable.
[0225] FIG. 47 shows an implementation where the heat transfer
layer is implemented on the same layer as the coil or is
constructed not to overlap the coil structure. This can be used in
cases where each layer of a PCB contains a coil structure such as
when a two or more layered PCB contains two or more layers of coils
in parallel to reduce resistance or two coils are placed on the two
sides of a PCB to provide a center-tapped coil pattern or other
geometries or simply when a single sided PCB structure is used and
a heat transfer layer on the same side is desired. In this case,
the coil is terminated with an inner radius that allows a central
portion without the coil for better heat transfer and/or lower eddy
current effects. However, this inner radius can be zero as shown in
FIG. 46 as well. In either case, in this implementation, any
potential heat generated at the coil is distributed by the metallic
pattern outside of the coil to surrounding areas without allowing
generation of circular eddy currents due to the alternating
inductive magnetic fields. The heat transfer pattern can be any
pattern that reduces or eliminates the possibility of circular
motion of carriers or electrons around the coil. The heat transfer
layer is separated by a finite gap from the metal coil layer to
avoid electrical contact but the gap should preferably be kept
small to allow efficient heat transfer between the two sections. To
improve transfer of heat across the gap, several additional
techniques can be used. This includes a PCB base material with high
thermal conductivity, an additional layer over the gap with high
thermal conductivity (such as ceramic or high thermal conductivity
plastic or thermal grease, etc.) or other similar methods can be
used.
[0226] It will be apparent to the person knowledgeable in the art
that several general embodiments are describe herein and the
concepts can also be expanded to include other similar geometries.
The foregoing description of the present invention has been
provided for the purposes of illustration and description. It is
not intended to be exhaustive or to limit the invention to the
precise forms disclosed. The embodiments were chosen and described
in order to best explain the principles of the invention and its
practical application, thereby enabling others skilled in the art
to understand the invention for various embodiments and with
various modifications that are suited to the particular use
contemplated. It is intended that the scope of the invention be
defined by the following claims and their equivalence.
[0227] Some aspects of the present invention may be conveniently
implemented using a conventional general purpose or a specialized
digital computer, microprocessor, or electronic circuitry
programmed according to the teachings of the present disclosure.
Appropriate software coding can readily be prepared by skilled
programmers and circuit designers based on the teachings of the
present disclosure, as will be apparent to those skilled in the
art.
[0228] In some embodiments, the present invention includes a
computer program product which is a storage medium (media) having
instructions stored thereon/in which can be used to program a
computer to perform any of the processes of the present invention.
The storage medium can include, but is not limited to, any type of
disk including floppy disks, optical discs, DVD, CD-ROMs,
microdrive, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs,
DRAMs, VRAMs, flash memory devices, magnetic or optical cards,
nanosystems (including molecular memory ICs), or any type of media
or device suitable for storing instructions and/or data.
[0229] The foregoing description of the present invention has been
provided for the purposes of illustration and description. It is
not intended to be exhaustive or to limit the invention to the
precise forms disclosed. Many modifications and variations will be
apparent to the practitioner skilled in the art. Particularly,
while the embodiments of the systems and methods described above
are described in the context of charging pads, it will be evident
that the system and methods may be used with other types of
chargers and/or power supplies. Similarly, while the embodiments
described above are described in the context of charging mobile
devices, other types of devices can be used. The embodiments were
chosen and described in order to best explain the principles of the
invention and its practical application, thereby enabling others
skilled in the art to understand the invention for various
embodiments and with various modifications that are suited to the
particular use contemplated. It is intended that the scope of the
invention be defined by the following claims and their
equivalence.
* * * * *