OUOYANYAAAAA
`
`US 2007027900241
`
`as) United States
`a2) Patent Application Publication co) Pub. No.: US 2007/0279002 A1
`PARTOVI
`(43) Pub. Date:
`Dec. 6, 2007
`
`(54) POWER SOURCE, CHARGING SYSTEM,
`AND INDUCTIVE RECEIVER FOR MOBILE
`DEVICES
`
`(76)
`
`Inventor:
`
`AFSHIN PARTOVI,
`SUNNYVALE, CA (US)
`Correspondence Address:
`FLIESLER MEYERLLP ve ea
`650 CALIFORNIA STREET, 14TH FLOOR
`SAN FRANCISCO, CA 94108
`
`(21) Appl. No.:
`
`11/757,067
`
`(22)
`
`Filed:
`
`Jun. 1, 2007
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/810,262,filed on Jun.
`1, 2006, provisional application No. 60/810,298,filed
`on Jun. 1, 2006, provisional application No. 60/868,
`674, filed on Dec. 5, 2006.
`
`Publication Classification
`
`(51)
`
`7
`Int. Cl.
`HO2J 7/00
`(2006.01)
`(52) US. Ch.
`ceccccccccsecsssecssecssecsstessscsssesssseessessevess 320/115
`
`ABSTRACT
`(97)
`A powersource, charging system, and inductive receiver for
`mobile devices. A pad or similar base unit comprises a
`primary, which creates a magnetic field by applying an
`alternating current to a winding, coil, or any type ofcurrent
`carrying wire. A receiver comprises a means for receiving,
`the energy from the alternating magnetic field and transfer-
`ring it to a mobile or other device. The receiver can also
`comprise electronic components or logic to set the voltage
`and current to the appropriate levels required by the mobile
`device, or to communicate information or data to and from
`the pad. The system may also incorporate efliciency mea-
`sures that improvetheefliciency ofpower transfer between
`the charger and receiver.
`
`104
`
`104
`
`1
`
`ANKER 1005
`ANKER1005
`
`1
`
`

`

`Patent Application Publication
`
`Dec. 6,2007 Sheet 1 of 11
`
`US 2007/0279002 Al
`
`100~,
`
`104
`
`104
`
`Mojo Pad
`“Charger 116|[120 Receiver~ ms
`
`10~,
`
`112
`
`.
`
`FIG. 1
`
`FIG. 2
`
`2
`
`

`

`Patent Application Publication
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`Dec. 6,2007 Sheet 2 of 11
`
`US 2007/0279002 Al
`
`140~
`
`3
`
`

`

`Patent Application Publication
`
`Dec. 6,2007 Sheet 3 of 11
`
`US 2007/0279002 Al
`
`
`174
`
`Reguiator
`
`172
`
`182
`
`FIG. 6
`
`FIG. 5
`
`170
`
`™
`
`Capacitor
`176
`
`Rectifier
`
`4
`
`

`

`Patent Application Publication
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`Dec. 6,2007 Sheet 4 of 11
`
`US 2007/0279002 Al
`
`199
`
`Shell/Cover
`194
`
`192
`
`200 ~
`Replacement
`Shell/Cover
`210
`
`PowerJack
`196
`
`212
`
`|ld ou
`
`With Original Shell
`
`Shell With Receiver
`
`FIG. 7
`
`Interconnects
`for Power/Data
`
`228
`
`Communications/
`Storage Unit
`230
`234
`
`220~.
`
`224
`
`226
`
`5
`
`

`

`Patent Application Publication
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`Dec. 6,2007 Sheet 5 of 11
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`US 2007/0279002 Al
`
`Charger
`
`Receiver
`
` RFID
`
`Reader
`
`
`
`6
`
`

`

`Patent Application Publication
`
`Dec. 6,2007 Sheet 6 of 11
`
`US 2007/0279002 Al
`
`296
`
`Regulator L2
`
`292
`
`woph°Faoa
`
`ReceivedPower(W)oO=Nwons?ANAWoO
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`0
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`025
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`05
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`075
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`1
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`Offset (Radius, r)
`
`FIG. 12
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`7
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`Patent Application Publication
`
`Dec. 6,2007 Sheet 8 of 11
`
`US 2007/0279002 Al
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`330~,
`FIG. 15
`
`FIG. 16
`
`9
`
`

`

`Patent Application Publication
`
`Dec. 6,2007 Sheet 9 of 11
`
`US 2007/0279002 Al
`
`Vbat
`
`Regulator
`
`L2
`
`PCB Coil
`
`Multilayer
`
`10
`
`

`

`Patent Application Publication
`
`Dec.6,2007 Sheet 10 of 11
`
`US 2007/0279002 Al
`
`Electronics
`
`364 %_
`Battery
`
`FIG. 19
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`Battery
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`FIG. 20
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`11
`
`11
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`

`

`Patent Application Publication
`
`Dec. 6,2007 Sheet 11 of 11
`
`US 2007/0279002 Al
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`

`

`US 2007/0279002 Al
`
`Dec. 6, 2007
`
`POWER SOURCE, CHARGING SYSTEM,
`AND INDUCTIVE RECEIVER FOR MOBILE
`DEVICES
`
`CLAIM OF PRIORITY
`
`[0001] This application claims the benefit of provisional
`patent applications “MOBILE DEVICE, CHARGER, AND
`POWER SUPPLY”, Application No. 60/810,262, filed Jun.
`1, 2006; “MOBILE DEVICE, BATTERY, CHARGING
`SYSTEM, AND POWER SUPPLY SYSTEM”, Application
`No. 60/810,298, filed Jun. 1, 2006; and “SYSTEM AND
`METHODFOR PROVIDING AND USING A PORTABLE
`
`INDUCTIVE POWER SOURCE”, Application No. 60/868.
`674, filed Dec. 5, 2006; each of which applications are
`hereby incorporated by reference herein.
`
`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 anyoneofthe 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.
`[0003]
`1. Field ofthe Invention
`[0004] The invention is related generally to power sup-
`plies, power sources,
`inductive power sources, charging
`systems, mobile devices, mobile device chargers, and bat-
`teries.
`
`2. Background
`[0005]
`[0006] There is currently a need for powering portable or
`mobile devices for use in commercial, business, personal,
`consumer, and other applications. Examples of such devices
`include cellular
`telephones, personal digital assistants
`(PDAs), notebook computers, mobile email devices, Black-
`berry devices Bluetooth headsets, music players
`(for
`example, MP3 players). radios, compact disk players, video
`gameconsoles, digital cameras, electric shavers, andelectric
`toothbrushes. Most of these devices include a rechargeable
`internal battery that must be first charged by an external
`powersupplyor charger, before the device itself can be used.
`The power supply typically provides direct current (DC)
`voltage through a special connector to the device. The power
`supply can then be disconnected, and the device will con-
`tinue to run for a short period of time until the battery is
`depleted. The voltage and power requirements of the differ-
`ent devices vary, and to date there is currently no standard-
`ized connector for the devices, As a result of this, each
`mobile device is invariably sold or distributed bundled with
`its own charger. The costs associated with these multiple
`different
`types and numbers of charger are paid by the
`consumer indirectly by being incorporated into the prices
`being charged for the mobile device.
`[0007] The rapid increase in the total number and variety
`of mobile products has meant that most people have several
`of the above-mentioned devices. In a typical day, that user
`would have to separately connect their multiple devices to
`each of their appropriate chargers for charging of each
`device. In addition, many people find it necessary to charge
`their devices in different locations suchas their offices and
`
`cars. Thus, many users have purchased additional chargers
`
`for their offices and cars, for use in charging their mobile
`phones, notebook computers, and music players in those
`locations.
`
`the above situation has
`that
`It will be evident
`[0008]
`caused typical users to have a multitude of incompatible
`devices (1.e. power supplies and chargers) that essentially
`provide the same function of charging a mobile device, but
`because ofthe number and variety that must be kept by the
`user are inconvenient
`to use.
`In many situations, users
`simply forget to charge their devices, or else find they need
`to recharge their device in situations where no appropriate
`charger is available. This leads to loss ofability to use the
`device when desired or needed.
`
`In addition, whentraveling way from home, mobile
`[0009]
`users have a particular problemin that they need to pack and
`carry the multiple chargers for their devices.
`In many
`situations, these chargers are bulkier and heavier than the
`devices themselves, and use of these devices in foreign
`countries requires clumsy adaptors, and sometimes voltage
`converters. This leads to a high degree of inconvenience for
`the ever-more-mobile consumer.
`[0010]
`In addition, the power connector for the mobile
`devices is often cheaply manufactured, and a source of
`mechanical and electrical failure. In many applications, such
`as toothbrushes or applications where the device is exposed
`to water and needs to be hermetically sealed, such a physical
`connection can not be used. Thus an alternative means of
`powering those types of devices must be used.
`[0011]
`Several products have tried to address this situa-
`tion. Some companies proposethe use ofa universal charger
`that consists of a power supply base unit, and interchange-
`abletips that bothfit into the base unit and inturnfit different
`devices. The tip includes a customized regulatorthat sets the
`voltage required by the particular device. However, a user
`must carry the multiple tips he or she needs for each of the
`various devices they have, and then charge each device
`serially by connecting the device to the power supply. While
`this product reducesthe overall weight of the charging tools
`the user mustcarry, the userstill needs to carry and exchange
`the tips to connect to different devices. In addition,
`the
`charging of multiple devices simultaneously is often not
`possible.
`[0012] Realizing that a power supply typically contains a
`transformer for voltage conversion, another approach is to
`split the transformer into twoparts: a first part can contain
`the first winding and the electronics to drive this winding at
`the appropriate operating frequency, while the second part
`consists of a winding where power is received and then
`rectified to obtain DC voltage. If the two parts are brought
`into physical proximity to each other, power is transformed
`from the first part to the second inductively, i.e. by induction,
`without any physical electrical connection. This is the
`approachthat is used in manyelectrical toothbrushes, shav-
`ers, and other products that are expected to be used in wet
`environments. However, a common problem with such
`inductive units is that the windings are bulky, whichrestricts
`their use in lightweight portable devices. Furthermore,
`to
`achieve adequate powertransfer, the parts must be designed
`to fit together suitably so that their windings are closely
`aligned. This is typically done by molding the device casing
`(for example, an electric toothbrush) and its charger/holder
`so that they fit together in only one suitable way. However,
`the molded base and shape of the portable device means they
`cannot be used in a universal fashion to powerother devices.
`
`13
`
`13
`
`

`

`US 2007/0279002 Al
`
`Dec. 6, 2007
`
`Some companies have proposed pad-like charging
`[0013]
`devices based oninductive concepts, but that also ostensibly
`allow for different types of devices to be charged. These
`pads typically includes grids of wires in an x and y direction,
`that carry anelectrical current, and that generate a uniform
`magnetic field parallel to the surface of the pad. A secondary
`coil wound around a magnetic core lies on the surface of the
`pad and picks up the magnetic field parallel to the surface,
`and in this manner energy can be transferred. However, each
`of these methods suffer from poor powertransfer, in that
`most of the power in the primary is not picked up in the
`secondary, and thus the overall power efliciency of the
`charger is very low. In addition, the magnetic cores used for
`the primary and secondary are often bulky and add to the
`total cost and size of the system, and limit incorporation into
`many devices.
`[0014] Anotherpoint to noteis that, while all of the above
`devices allow a user to charge a device, they also require the
`charging device or base unit to be electrically connected to
`a power source, such as a poweroutlet or a DC source. In
`many cases, the user may not have access to such a power
`source such as when traveling, camping, or working in an
`area without access to power. However, to date, no device
`has been provided that
`is portable., and that allows for
`inductive charging of multiple devices with differing power
`requirements, and which itself can be intermittently or
`occasionally charged either by an external power source, or
`by other means, or that is self-powered or includes its own
`powersource.
`
`SUMMARY
`
`[0015] A power source, charging system, and inductive
`receiver for mobile devices is disclosed herein. In accor-
`
`dance with an embodiment, a pad or similar base unit
`comprises a primary., which creates a magnetic field by
`applying an alternating current to a winding, coil, or any
`type of current carrying wire. A receiver comprises a means
`for receiving the energy fromthe alternating magnetic field
`and transferring it to a mobile or other device. The receiver
`can also comprise electronic components or logic to set the
`voltage and currentto the appropriate levels required by the
`mobile device, or to communicate informationor data to and
`from the pad. The system may also incorporate efficiency
`measures that
`improve the efficiency of power transfer
`between the charger and receiver,
`[0016]
`In some embodiments the receiver can also com-
`prise electronic components or logic to set the voltage and
`current to the appropriate levels required by the mobile
`device, or to communicate information to the pad. In addi-
`tional embodiments, the system can provide for additional
`functionality such as communication of data stored in the
`electronic device or to be transferred to the device. Some
`embodiments may also incorporate efliciency measuresthat
`improvethe efficiency of powertransfer between the charger
`and receiver, and ultimately to the mobile device. In accor-
`dance with an embodiment the device includes aninternal
`battery for self-powered operation. In accordance with other
`embodiments the device can include a solar cell power
`source, hand crank, or other means of power supply for
`
`occasional self powered operation. Other embodiments can
`be incorporated into charging kiosks, automobiles, and other
`applications.
`
`BRIEF DESCRIPTION OF THE FIGURES
`
`1 shows a pad using multiple receiver/ener-
`FIG.
`[0017]
`gizer coils in accordance with an embodimentofthe inven-
`tion,
`FIG. 2 shows a figure of a circuit diagram in
`[0018]
`accordance with an embodimentofthe invention.
`
`FIG. 3 shows a charging pad using multiple coils in
`[0019]
`accordance with an embodiment ofthe invention.
`
`FIG. 4 shows a charging pad using multiple over-
`[0020]
`lapping coil layers in accordance with an embodimentof the
`invention.
`
`FIG. 5 shows the use of multiple coil types and
`[0021]
`sizes in overlapping pad layers in accordance with an
`embodiment ofthe invention.
`
`FIG. 6 showsa receiver with an integrated battery
`[0022]
`in accordance with an embodimentof the invention.
`
`FIG. 7 shows a coupling of receiver with a device
`[0023]
`to be charged in accordance with an embodiment ofthe
`invention.
`
`FIG. 8 shows a pad allowing modular or multiple
`[0024]
`connectivity in accordance with an embodiment of the
`invention.
`
`FIG. 9 shows a figure of a circuit diagram in
`[0025]
`accordance with an embodiment ofthe invention.
`
`FIG. 10 showsa figure of a circuit diagram in
`[0026]
`accordance with an embodiment ofthe invention.
`
`FIG. 11 shows a figure of a circuit diagram in
`[0027]
`accordance with an embodiment of the invention.
`
`FIG. 12 shows a figure of power transfer chart in
`[0028]
`accordance with an embodiment of the invention.
`
`FIG. 13 shows a figure of a coil layout
`[0029]
`dance with an embodiment of the invention.
`
`in accor-
`
`FIG. 14 shows a figure of a coil layout in accor-
`[0030]
`dance with an embodiment ofthe invention.
`
`FIG. 15 shows a figure of a charging pad with
`[0031]
`multiple coils in accordance with an embodiment of the
`invention.
`
`FIG. 16 shows a figure of a charging pad with
`[0032]
`movable coils in accordance with an embodiment of the
`invention.
`
`FIG. 17 shows a figure of a circuit diagram in
`[0033]
`accordance with an embodiment ofthe invention.
`
`FIG. 18 shows anillustration of a means ofstack-
`[0034]
`ing coils, in accordance with an embodiment ofthe inven-
`tion.
`
`FIG. 19 shows an illustration of a device for
`[0035]
`inductive power charging that includes an internal battery
`for self-powered operation, in accordance with an embodi-
`ment of the invention.
`
`FIG. 20 shows anillustration of an inductive
`[0036]
`charger unit with a solar cell power source for self powered
`operation, in accordance with an embodiment ofthe inven-
`tion.
`
`FIG. 21 shows anillustration of an inductive
`[0037]
`charger unit with an incorporated communications and/or
`storage unit,
`in accordance with an embodiment of the
`invention.
`
`14
`
`14
`
`

`

`US 2007/0279002 Al
`
`Dec. 6, 2007
`
`FIG. 22 shows anillustration of a kiosk that
`[0038]
`incorporates an inductive charger unit in accordance with an
`embodiment of the invention,
`
`embodiments can be incorporated into charging kiosks,
`automobiles, computer cases, and other electronic devices
`and applications.
`
`DETAILED DESCRIPTION
`
`Inductive Charging System
`
`[0039] A power source, charging system, and inductive
`receiver for mobile devices is disclosed herein. In accor-
`dance with an embodiment, a pad or similar base unit
`comprises a primary, which creates a magnetic field by
`applying an alternating current to a winding, coil, or any
`type ofcurrent carrying wire. A receiver comprises a means
`for receiving the energy fromthe alternating magnetic field
`and transferring it to a mobile or other device. The receiver
`can also comprise electronic components or logic to set the
`voltage and current to the appropriate levels required by the
`mobile device, or to communicate information or data to and
`from the pad. The system may also incorporate efficiency
`measures that
`improve the efficiency of power transfer
`between the charger and receiver.
`[0040]
`In some embodiments the receiver can also com-
`prise electronic components or logic to set the voltage and
`current
`to the appropriate levels required by the mobile
`device. In some embodiments, the receiver can also contain
`circuitry to sense and determinethe status of the electronic
`device to be charged, the battery inside, or a variety ofother
`parameters and to communicate this informationto the pad.
`In additional embodiments,
`the system can provide for
`additional functionality such as communication of data
`stored in the electronic device (for example,digital images
`stored in cameras, telephone numbers in cell phones, songs
`in MP3 players) or data into the device.
`[0041] Embodiments can also incorporate efliciency mea-
`sures that improve the efficiency of powertransfer between
`the charger and receiver, and ultimately to the mobile
`device. In accordance with an embodiment, the charger or
`power supply comprises a switch, (for example, a MOSFET
`device or another switching mechanism), that is switched at
`an appropriate frequency to generate an alternative current
`(AC) voltage across a primary coil, and generates an AC
`magnetic field. This field in turn generates a voltage in the
`coil in the receiverthatis rectified and then smoothed by a
`capacitor to provide power to a load, with the result being
`greater efficiency.
`[0042]
`In accordance with other embodimentsthe coils are
`mounted such that they can move laterally within the pad
`and within an area of their segments, while continuing to be
`connected to their driver electronics placed on the edges of
`the area, The floating coils and the drive circuit are sand-
`wiched in betweenthin upper and lower coverlayers that act
`to allow the coils lateral movement while limiting vertical
`movement. When a secondary is placed on the pad, the pad
`senses the positionof the secondary coil and movesthe coils
`to the right position to optimize powertransfer. Magnets can
`be used to better orient the coils and improve greater power
`transfer efficiency.
`[0043] Additional embodiments are also described herein.
`For example in accordance with an embodimentthe device
`includes an internal battery for self-powered operation. In
`accordance with other embodiments the device can include
`a solar cell power source hand crank, or other means of
`power supply for occasional self powered operation. Other
`
`[0044] While the above mentioned technologies describe
`various aspects ofinductive charging., they do not address
`the basic requirements that a consumer and manufacturer
`desire in such a product. These include the following desired
`features:
`
`[0045] The pad should be able to charge a number of
`devices with various power requirements efficiently. A
`typical number would be 1-6 devices, and probably up
`to 4 low power (up to 5 W) devices simultaneously,
`When multiple devices are being charged, a method for
`energizing only those coils near a device is preferable.
`[0046] The same pad should be able to power low-
`power devices (mobile phones, PDAs, cameras, game
`consoles, etc.) with power requirements of 5 W or less,
`and higher-power devices such as notebook computers
`(which often have a power requirement of 60 W or
`higher).
`[0047]
`‘The powertransfer efliciency between the pri-
`mary coil and the secondary should be maximized.
`Lack of efficiency in the powertransfer would neces-
`sitate larger and heavierAC to DC powersupplies. This
`would add cost and decrease product attractiveness to
`customers. Thus methods where the entire pad is ener-
`gized are not as attractive.
`[0048] A simple method for verification of the manu-
`facturer of the secondary, and possibly information for
`powerrequirements, should be supported as necessary
`to ensure product compatibility and to provide means
`of product registration and licensing.
`[0049] The EMI radiation from the system should be
`minimized, and ideally, the system should radiatelittle
`or no EMI with no device present. A charger should
`preferably not emit any power until an appropriate
`device is brought close to the chargeritself. In this way,
`electric power is not wasted, and electromagnetic
`poweris not emitted needlessly. In addition, accidental
`effects on magnetically sensitive devices suchas credit
`cards, disk drives and such are minimized.
`[0050]
`‘The pad and the receiver should be reasonably
`simple to construct, and cost effective. Since bothparts
`can be integrated into mobile devices, the overall size,
`weight, and form factor should be minimized.
`[0051] As used herein, the term charger can refer to a
`device for supplying power to a mobile or stationary device
`for the purpose of either charging its battery, operating the
`device at that moment in time, or both. For example, as is
`commonin portable computers, the power supply can oper-
`ate the portable computers or charge its battery, or accom-
`plish both tasks simultaneously.
`In accordance with an
`embodiment, the mobile device charger can have any suit-
`able configuration, such as the configuration of a flat pad.
`The power received by the mobile device from the mobile
`device charger (such as the primary in the mobile device
`charger) can be rectified in the receiver and smoothed by a
`capacitor before being connected to the rechargeable battery
`which is represented by the load in the picture above. To
`ensure proper charging of the battery, a regulator can be
`placed between the output of the receiver and the battery.
`This regulator can sense the appropriate parameters of the
`
`15
`
`15
`
`

`

`US 2007/0279002 Al
`
`Dec. 6, 2007
`
`battery (voltage, current, capacity), and regulate the current
`drawn from the receiver appropriately. The battery can
`contain a chip with information regarding its characteristics
`that can be read out by the regulator. Alternatively, such
`information can be stored in the regulator for the mobile
`device to be charged, and an appropriate chargingprofile can
`also be programmed into the regulator.
`[0052]
`FIG.
`1 shows a pad using multiple receiver/ener-
`gizer coils in accordance with an embodiment. In its sim-
`plest format, the mobile device charger or power supply
`preferably has a substantially flat configuration, such as the
`configuration of a pad 100, and comprises multiple coils or
`sets of wires 104. These coils or wires can be the same size
`as or larger thanthe coils or wires in the mobile devices, and
`can have similar or different shapes, including for example
`a spiral shape. For example, for a mobile device charger
`designed to charge up to four mobile devices of similar
`power (up to 10 W each) such as mobile handsets, MP3
`players, etc., four or more of the coils or wires would ideally
`be present in the mobile device charger. The charger pad or
`pad can be powered by plugging into a power source such
`as a wall socket. The pad can also be powered by another
`electronic device, such as the pad being powered throughthe
`USB outlet of a laptop or by the connector that laptops have
`at
`the bottom for interfacing with docking stations, or
`powering other devices. The pad can also be incorporated
`into a docking station, such as may be used by notebook
`computers.
`that
`[0053] A mobile device can include a receiver
`includes one or more coils or wires to receive the power
`from the mobile device charger. As described in further
`detail below, the receiver can be made part of the battery in
`the mobile device or of the shell of the mobile device. When
`it is part of the mobile device shell, the receiver can be part
`of the inside surface of the mobile device shell or of the
`outside surface of the mobile device shell. The receiver can
`be connected to the power input jack of the mobile device or
`can bypass the input jack and be directly connected to the
`battery. In any of these configurations, the receiver includes
`one or more appropriate coil or wire geometries that can
`receive power from the mobile device charger when it is
`placed adjacent to the mobile device charger. In accordance
`with an embodiment, the coils in the mobile device charger
`and/or the coils in the mobile devices can be printed circuit
`board (PCB) coils, and the PCB coils can be placed in one
`or more layers of PCB.
`[0054]
`Insome embodiments, the chargercan alsoitself be
`built into a mobile device. For example, a laptop computer
`or other portable or mobile device can incorporate a charger
`section so that other mobile devices can be charged as
`described above. Alternatively, using the sameset ofcoils or
`wires, or a separate set of coils or wires, any mobile device
`can itself be used as a charger to power or charge other
`mobile devices.
`
`the mobile
`In accordance with an embodiment,
`[0055]
`device charger or pad, and the various mobile devices, can
`communicate with each other to transfer data.
`In one
`embodiment, the coils in the mobile device charger that are
`used for powering the mobile device, or another set of coils
`in the same PCB layeror in a separate layer, can be used for
`data transfer between the mobile device charger and the
`mobile device to be charged or the battery directly. Tech-
`niques employed in radio and network communication, such
`as radio frequency identification (RFID) can be used. In one
`
`embodiment a chip connected to an antenna (for example,
`the secondary coil or separate data antenna) or another
`means oftransfer of information can be used to provide
`information about, for example, the presence of the mobile
`device, its authenticity (for example its manufacturer code)
`and the devices charging requirements (suchas its required
`voltage, battery capacity, and charge algorithmprofile).
`[0056]
`In accordance with an embodiment,
`a_
`typical
`sequence for charger operation can be as follows: The
`mobile device charger can be in a low powerstatus normally,
`thus minimizing power usage. However, periodically, each
`of the coils (or a separate data coil in another PCB layer)is
`powered up in rotation with a short signal such as a short
`radiofrequency (RF) signal that can activate a signal receiver
`in the secondary such as an RF ID tag. The mobile device
`chargerthentries to identify a return signal from any mobile
`device (or any secondary) that may be nearby. Once a mobile
`device (or a secondary) is detected the mobile device charger
`and the mobile device proceed to exchange information.
`This information can include a unique ID code that can
`verify the authenticity and manufacturer of the charger and
`mobile device, the voltage requirementsofthe battery or the
`mobile device, and the capacity of the battery. For security
`purposes or to avoid counterfeit device or pad manufacture,
`such information could be encrypted, as is common in some
`RFIDtags.
`[0057]
`In accordance with various embodiment, other
`protocols such as Near Field Communications (NFC) or
`Felica can be used, wherein the circuitry containing the [ID
`and the necessary information is powered either by the
`mobile device or remotely by the mobile device charger.
`Depending on the particular implementation needs, Blue-
`tooth, WiFi, and other information transfer processes can be
`used. Additional information regarding the charging profile
`for the battery can also be exchanged and can include
`parameters that would be used in a pre-programmed charge
`profile stored in the mobile device charger. However, the
`information exchanged could be as simple as an acknowl-
`edge signal that shows the mobile device charger that a
`mobile device is present. The charger can also contain means
`for detection and comparison Of the strength of the signal
`over different locations on the charger. In this way, it could
`determine the location of the mobile device on the charger,
`and then proceed to activate the appropriate region for
`charging.
`In some embodiments that require greater simplic-
`[0058]
`ity, no communication need take place between the mobile
`device charger and the mobile device. In some embodiments
`the mobile device charger can sense the mobile device by
`detecting a change in the conditions ofa resonant circuit in
`the mobile device charger when the mobile device is brought
`nearby. In other embodiments the mobile device can be
`sensed by a number of proximity sensors such as capaci-
`tance, weight, magnetic, optical, or other sensors that deter-
`mine the presence of a mobile device near a coil in the
`mobile device charger. Once a mobile device is sensed near
`a primary coil or section of the mobile device charger, the
`mobile device charger can then activate that primary coil or
`section to provide powerto the secondary coil in the mobile
`device’s battery shell, receiver module or the deviceitself.
`
`Inductive Charging Circuit
`
`[0059] Each mobile device and its battery has particular
`characteristics (voltage, capacity, etc.). In order to facilitate
`
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`US 2007/0279002 Al
`
`Dec. 6, 2007
`
`these different devices with a single universal mobile device
`chargers several circuit architectures are possible, some of
`which are described in further detail below.
`
`FIG. 2 shows the main components of a typical
`[0060]
`inductive powertransfer system 110. The circuit illustrated
`is used to illustrate the principle of inductive power transfer
`and is not meant to be limiting to the present invention. In
`accordance with an embodiment, the charger 112 comprises
`a power source 118, and a switch T 126 (which can be a
`MOSFETorother switching mechanism) that is switched at
`an appropriate frequency to generate an AC voltage across
`the primary coil Lp 116 and generate an AC magneticfield.
`This field in turn generates a voltage in the coil 120 in the
`receiver 114 thatis rectified and then smoothed by a capaci-
`tor to provide power 122 to a load RI 124. For ease ofuse,
`a receiver can be integrated with a mobile device, such as
`integrated inside the mobile device or attached to the surface
`of the mobile device during manufacture,
`to enable the
`device to receive power inductively from a mobile device
`charger or integrated into, or on its battery.
`[0061] The mobile device or
`its battery typically can
`include additional rectifier(s) and capacitor(s) to change the
`ACinduced voltage to a DC voltage. This is then fed to a
`regulator chip which includes the appropriate information
`for the battery and/or the mobile device. The mobile device
`charger provides powerand the regulation is provided by the
`mobile device. The mobile device charger, after exchanging
`information with the mobile device, determines the appro-
`priate charging | powering conditions to the mobile device.
`It
`then proceeds to power the mobile device with the
`appropriate parameters required. For example,
`to set the
`mobile device voltage to the right value required, the value
`of the voltage to the mobile device charger can be set.
`Alternatively, the duty cycle of the charger switching circuit
`or its frequency can be changed to modify the voltage in the
`mobile device. Alternatively, a combination of the above
`two approaches can be followed, wherein regulation is
`partially provided by the charger, and partially by the
`circuitry in the secondary.
`
`Inductive Charger
`
`To allow the operationofthe mobile device charger
`[0062]
`regardless ofposition of the mobile device, the total area of
`the mobile device charger can be covered by coils or by
`another wire geometry that creates magnetic field. FIG. 3
`shows a charging pad using multiple coils in accordance
`with an embodimentof th