`
`(12)UK Patent Application (19)GB <11)2 389 720 (13)A
`
`(43) Date of A Publication
`
`17.12.2003
`
`
`(51)
`INT CL7:
`(21) Application No:
`022689313
`H01F38/14, H02J 7/02
`
`(22) Date of Filing:
`
`18.11.2002
`
`
`
`(30) Priority Data:
`(31) 0213374
`(32) 10.06.2002
`(33) GB
`
`
`
`
`(71) Applicant(s):
`
`Clty University of Hong Kong
`(Incorporated In Hong Kong)
`Tat Chee Avenue, Kowloon Tong,
`Kowloon, Hong Kong
`
`(52) UK CL (Edition V):
`H2H HAM HBCH
`H1T T1C T1F T12 T7A5 T7C5 T9
`U1S 82199 82215
`
`(56) Documents Cited:
`US 6008622 A
`
`US 5959433 A
`
`(58) Field of Search:
`UK CL (Edition v ) H1T, H2H
`INT CL7 H01F, H02J
`Other: Onllne: WPl, PAJ, EPODOC
`
`
`
`
`(72)
`
`'"V‘amrlsli
`Ron Shu-Yuen Hui
`
`(74) Agent and/or Address for Service:
`Lloyd Wise
`Commonwealth House,
`1-19 New Oxford Street, LONDON,
`WC1A 1LW, United Kingdom
`
`
`
`
`(54) Abstract Title: Planar Inductive battery charger
`
`(57) A battery charger system having a charging module
`with a planar charging surface 2 for receiving an
`electronic device 3 to be charged. The module
`includes a primary charging circuit having the
`primary winding of a transformer (fig. 40). The
`primary winding is substantially parallel to the planar
`charging surface 2. The primary winding has
`electromagnetic shielding 5,6 on the side of the
`winding opposite the planar charging surface 2. The
`
`electronic device 3 includes a secondary winding.
`
`FIG.4(b)
`
`7
`
`VOZL688Z85)
`
`At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 001
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 001
`
`

`

`
`
`charger
`
`
`
`FIGJ (PRIOR ART)
`
`Magnetic
`core for
`
`primary
`winding
`
`Primary
`winding
`
`Magnetic
`core for
`secondary
`wmdmg
`
`Secondary
`.
`Winding
`
`-
`
`E]
`
`[El
`
`" " ”"
`
`.
`
`m E
`‘
`‘
`
`Air gap
`
`FIG.2 (PRIOR ART)
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 002
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 002
`
`

`

`
`
`.7 7--. Ferrite Plate
`
`
`~— Copper Sheet
`
`-_ Thermally Conductive
`insulating Layer
`
`
`‘1
`r- Polyurethanemated
`
`A
`/ J
`Insulated Copper \Mres
`
`l 16: \ Dielectric Laminate
`
`
`
`
`1/
`
`FIG.4(b)
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 003
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`Momentum Dynamics Corporation
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`Page 003
`
`

`

`95/27
`
`FIG.4(C)
`
`FIG.5(a)
`
`FIG.5(b)
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 004
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 004
`
`
`
`
`

`

`
`
`FIG.6(a)
`
`Mnglud:
`
`(dBuV)
`
`\ flnllli
`
`i011
`
`l)
`
`:0
`
`00
`u)
`\vmm)
`
`FIG.6(b)
`
`—
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 005
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 005
`
`

`

`FIG.7(a)
`
`Magnetic
`flux
`
`magnitude
`
`distance
`
`FIG.7(b)
`
`
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 006
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 006
`
`

`

`(‘0!-
`
`i‘J
`
`
`
`FIG.9(a)
`
`dBuV
`IJO
`
`125
`
`120
`
`95
`
`Mdgnlludc(dBuV)
`
`
`
`1:0
`
`FIG.9(b)
`
`"[15
`NO
`
`105
`
`l()()
`
`" as
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 007
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 007
`
`

`

`FIG. 10(a)
`
`FIG. 10(b)
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 008
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 008
`
`
`
`

`

`55(17
`
`Energy coupled zones
`
`_, .ww.
`
`.,
`
`
`Buttery ioad High-
`
`fxcquency
`AC voltage
`SOUI'CE
`
`Secondary
`Winding
`
`Groups of
`primary wmdmgs
`
`FIG. 10(c)
`
`
` Mechanical contacts for
`
`_-__,,-.-.-—--~ "‘
`
`Integrated
`secondary charger
`system
`
`connection with the battery puck
`
`FIG.“
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 009
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 009
`
`

`

`q/ZY
`
`FIG.12(a)
`
`PCB winding ofthe
`. secondary charger
`system
`
`' EMI shield(copper sheet)
`
`'
`
`“ EMI shield(fernte sheet)
`
`connection with the battery pack
`
`FIG.12(b)
`
`....
`
`PCB winding of the
`secondary charger
`syetem
`
`EMI shiekiflerrite sheet) “
`
`. EMI ghleldmoppcraheet)
`
`Rectifier circuit
`
`\ Mechanical contacts for
`connection with the battery pack
`
`FIG.12(c)
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 010
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 010
`
`

`

`tOl'Z7
`
`PCB winding of the
`
`EMI shield(copper sheet)
`
`EMI shield(fcm‘te sheet)
`
`\ Mechanical contacts for
`
`connection with the battery pack
`
`HGJum
`
`cover
`
`Non-metallic
`
`Hoixa
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 011
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 011
`
`

`

`,, 25 Non-metallic cover
`
`¢—’/"'
`
`SQv/ “y“
`
`r_/A_:_i-.—«- E4
`
`PCBwindingwithrectifierCil'CUil
`
`Mechanical — ->
`contacts
`
`'
`
`V4‘,--~7—~r E3 EMI shieid(fcrrite sheet)
`O __-__._7-’—-——88 EMIshieidtcoppersheet)
`
`20
`
`FIG. 13(b)
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 012
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 012
`
`

`

`@117
`
`Cable
`connection
`
`31
`
`Connection to
`
`the power source
`
`
`
`
`
`EMI shield
`
`Charging surface
`consisting of ( l)
`insulation top cover,(2)
`planar PCB primary
`windings and (3) bottom
`
`Electronic
`charging circuit
`
`3'8
`
`FIG. 14
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 013
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 013
`
`

`

`\Efllfl1
`
`
`
`FIG.16
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 014
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 014
`
`

`

`\%/17
`
`
`
`
`
`
`
`
`
`
`FIG. 18
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 015
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 015
`
`

`

`\Si21
`
`L ........ ..JL_.-..—_.--JL ..... .__....JL .......... J
`
`1r"""‘"“'\
`II
`u
`.-
`II
`II
`u
`u
`u
`||
`II
`JL __________ J
`"I' """"" 1
`II
`n
`u
`n
`u
`H
`N
`IInn
`JL-.-
`1r'—-
`iun
`
`nnI
`
`II
`n
`u
`II
`bl
`n
`n
`..
`‘I
`II
`_ ...... JL...
`“"""|f'"'
`II
`n
`n
`..
`..
`u
`II
`Ii
`
`uuHI
`
`In
`
`FIG.19
`
`unu F
`
`"“'1I’""
`
`IG.20
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 016
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 016
`
`

`

`
`
`Magnetic field magnitude dtstnbutton tn the second layer
`
`r"\
`
`’1
`
`I
`/
`I
`
`I
`
`\\
`
`\
`
`\
`\
`\
`
`ll
`
`I
`
`I
`
`I
`
`I
`
`r"\
`
`\\
`
`\
`
`\
`\
`\
`
`I!
`
`I
`
`I
`
`I
`I
`
`l"\
`
`\\
`
`\
`
`\
`\
`
`\
`
`Distance
`
`Distance
`
`
`
`
`l
`
`-
`
`Resultant magnetic field magnitude distn‘bution tn the mum-layer structure
`
`Distance
`
`FIG.21
`
`FIG.23
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 017
`
`@ F
`
`IG.22
`
`320._.
`I)
`u.
`.2 'U
`a .2c :
`
`2 :
`
`2
`2
`tv
`"‘ O
`U '3
`2 J
`I2) .2
`no Eu5 q
`2 E
`
`
`
`MagnumFtcltt
`
`magnitude
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 017
`
`

`

`o o o o
`>.o.o.o.o
`O O O C
`O O O O
`>. .0 O O
`
`(i
`
`L’UD
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 018
`
`

`

`3 FIG.25
`
`mmf
`
`F1026
`
`i 0
`
`0
`
`.5 _
`
`GO;
`
`FIG.27
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 019
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 019
`
`

`

`\Ci/Zi
`
`wNOE
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 020
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 020
`
`

`

`10/27
`
`FIG.29
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 021
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 021
`
`

`

`zi/Z7
`
`FIG.3O
`
`
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 022
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 022
`
`

`

`'IIIIII.‘.-«.-.n.'QIIIII\
`
`
`
`......-.-'lllll-‘
`
`
`
`...-u..."IOIII‘u....u.-u-
`
`1127
`
`
`
`nuncur......l
`
`...
`
`AIIIII‘:....-..
`
`.'o
`
`..
`
`IIIIIV3......
`
`.Pt
`
`
`
`...-nu»........
`
`.a
`
`
`
`III-l13......
`
`..
`
`IIIIIVa...
`
`Inllt‘........OnuO'
`
`
`
` Illllfi.......uAlllllq..-......
`
`.\.§
`
`-'O
`
`
`
`nun-av........
`
`u‘i
`
`
`
`
`
`
`
`3...... IIIIIV.~...-.Allllli
`
`ufio
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 023
`
`.r.o
`
`.aInn-II.......
`
`
`
`
`
`
`
`Inc-0v...rural-Iv
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 023
`
`
`
`
`
`
`
`
`
`
`
`

`

` LZICO'FL
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 024
`
`

`

`1w /27
`
`
`
`Distance
`
`F1033
`
`FIG.34
`
`FIG.35
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 025
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 025
`
`

`

`IIIDII
`IIIDII
`III-II
`IIUII
`
`FIG.36
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 026
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 026
`
`

`

`.l H
`
`I
`
`ll
`
`H
`
`FIG.38
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 027
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 027
`
`

`

`
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 028
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 028
`
`

`

`2389720
`
`PLANAR INDUQI IYE EA LI} ERY CHARGE}:
`
`FIELD OF THE INVENTION
`
`This invention relates to a battery charger, and in particular to a battery charger
`
`having a planar surface on which one or more battery powered devices may be placed
`
`10
`
`for battery recharging through induction.
`
`BACKGROUND OF THE INVENTION
`
`Portable electronic equipment such as mobile phones, handheld computers,
`
`personal data assistants, and devices such as a wireless computer mouse, are normally
`
`is
`
`powered by batteries. In many cases, rechargeable batteries are preferred because of
`
`environmental
`
`and economical concerns. The most common way to charge
`
`rechargeable batteries is to use a conventional charger, which normally consists of an
`
`AC-DC power supply (in case of using the ac mains) or a DC-DC power supply (in
`
`case of using a car battery). Conventional chargers normally use a cord (an electric
`
`20
`
`cable for a physical electrical connection) to connect the charger circuit (a power
`
`supply) to the battery located in the portable electronic equipment. The basic schematic
`
`of the conventional battery charger is shown in Fig.1.
`
`PRIOR ART
`
`25
`
`Inductive electronic chargers without direct physical electrical connection have
`
`been developed in some portable electronic equipment such as electric toothbrushes
`
`where because they are designed to be used in the bathroom in the vicinity of sinks and
`
`water, it is not safe to provide a conventional electrical connection. USG,356,049,
`
`US6301,128, (£6,118,249, also all describe various forms of inductive chargers. These
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 029
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 029
`
`

`

`inductive type chargers, however, use traditional transformer designs with windings
`
`wound around ferrite magnetic cores as shown in Fig.2. The main magnetic flux
`
`between the primary winding and secondary winding has to go through the magnetic
`
`core materials. Other contactless chargers proposed also use magnetic cores as the main
`
`structure for the coupled transformer windings.
`
`A contactless charger using a single primary printed winding without any EMI
`
`shielding has been proposed by Choi et a] in “A new contactlcss battery charger for
`
`portable telecommunications/computing electronics" ICCE International Conference on
`
`Consumer Electronics 2001 Pages 58-59. However, the magnetic flux distribution of a
`
`10
`
`single spiral winding has a major problem of non-uniform magnetic flux distribution.
`
`As illustrated further below, the magnitude of the magnetic field in the centre of the
`
`core of a spiral winding is highest and decreases from the centre. This means that if the
`
`portable electronic device is not placed properly in the central region, the charging
`
`effect
`
`is not effective in this non-uniform field distribution. Furthermore. without
`
`15
`
`proper EMI shielding, undesirable induced currents may flow in other metallic parts of
`
`the portable electronic equipment.
`
`SUMMARY OF THE INVENTION
`
`According to the present invention there is provided a battery charger system
`
`20
`
`comprising a charging module comprising a primary charging circuit and being fanned
`
`with a planar charging surface adapted to receive an electronic device to be charged,
`
`wherein said primary charging circuit includes the prirnary winding of a transformer,
`
`said primary winding being substantially parallel to said planar charging surface,
`
`wherein said primary winding is provided with electromagnetic shielding on the side of
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 030
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 030
`
`

`

`said winding opposite from said planar charging surface, and wherein said electronic
`
`device is formed with a secondary winding.
`
`In a preferred embodiment the primary winding is formed on a planar printed
`
`circuit board.
`
`Preferably the magnetic flux generated by the primary winding is substantially
`
`uniform over at least a major part ofthe planar charging surface. In this way the precise
`
`position and orientation of the electronic device on the charging surface is not critical.
`
`To achieve this the charging module may comprise a plurality of primary windings.
`
`which may preferably be disposed in a regular array.
`
`In
`
`a preferred
`
`embodiment
`
`the primary winding
`
`is
`
`provided with
`
`electromagnetic shielding on the side of said winding opposite from said planar
`
`charging surface. This shielding may include a sheet of ferrite material. and more
`
`preferably also may firrther include a sheet of conductive material such as copper or
`
`aluminium
`
`It is an advantage of the present invention that in preferred embodiments the
`
`planar charging surface may be large enough to receive two or more electronic devices,
`
`and the primary charging circuit
`
`is adapted to charge two or more devices
`
`simultaneously.
`
`In this way it
`
`is possible to charge more than one device
`
`simultaneously. For example the planar charging surface may be divided into a
`
`plurality of charging regions, which regions may be defined by providing a plurality of
`‘ primary transformer windings arranged in a regular array and connecting the windings
`
`in groups to define said charging regions. A further advantage of the present invention
`
`is that it enables the possibility of allowing a device to move over the charging surface
`
`while being charged at the same time. This possibility is particularly useful to a device
`
`which is designed to be moved such as a wireless computer mouSe
`
`10
`
`15
`
`20
`
`25
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 031
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 031
`
`

`

`O
`
`Viewed from another aspect the present invention provides a battery charging
`
`system comprising a charging module comprising a primary charging circuit and being
`
`formed with a charging surface for receiving an electronic device to be charged,
`
`wherein said charging module comprises a plurality of transformer primary windings
`
`5
`
`arranged in a regular array.
`
`In addition to the battery charging system,
`
`the invention also extends to a
`
`battery powered portable electronic device comprising a rechargeable battery. and
`
`wherein the device includes a planar secondary winding for receiving electrical energy
`
`from a battery charger, and electromagnetic shielding between the winding and the
`
`10
`
`major electronic components of said device.
`
`Preferably the shielding comprises a sheet of ferrite material and a sheet of
`
`conductive material such as copper.
`
`Preferably the winding is formed integrally with a back cover of said device.
`
`An important aspect of the present
`
`invention is that it provides a battery
`
`15
`
`charging system that employs a localised charging concept. In particular, when there is
`
`an array of primary coils, it will be understood that energy is only transferred from
`
`those primary coils that are adjacent the secoudary coil located in the device being
`
`charged. In other words, when a device is placed on a planar charging surface that is
`
`greater in size than the device, energy is only transferred from that part of the planar
`
`20
`
`charging surface that is directly beneath the device, and possibly also immediately
`
`adjacent areas that are still able to couple to the secondary coil.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Some embodiments of the invention will now be described by way of example
`
`25
`
`and with reference to the accompanying drawings, in which:-
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 032
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 032
`
`

`

`Fig.1 is a schematic view of a conventional prior art battery charger with direct
`
`electrical connection.
`
`Fig.2 is a schematic view of a conventional magnetic core-based transformer as
`
`used in prior art inductive battery charger systems,
`
`Fig.3 is a schematic view of a planar transfonner with shielding,
`
`Figs.4(a)—(c) are (a) a perspective View of a battery charger system according to
`
`an embodiment of the present invention, (b) a view similar to (a) but showing
`
`the structure of the primary charging system, and (c) a view similar to (a) and (b)
`
`but showing the top cover removed for clarity,
`
`10
`
`Figs.5(a) & (b) show the structure of the primary charger with the top cover
`
`removed for clarity, and in Fig.5(a) With the structure shown in exploded view,
`
`Figs.6(a) & (b) show (a) a single spiral PCB winding, and (b) the measured
`
`magnetic field distribution of a single spiral winding,
`
`Figs.7(a) & (b) illustrate the use of a magnetic core to control magnetic field
`
`15
`
`distribution,
`
`Fig.8 shows an embodiment of the invention in which a plurality of primary
`
`windings are arranged in an array Structure,
`
`Figs.9(a) & (b) shOWS (a) a 4 x 4 primary winding array, and (b) the resulting
`
`magnetic field distribution,
`
`20
`
`Figs.10(a)-(c) illustrate an embodiment of the invention in which primary
`
`windings are arranged in groups with Fig.10(e) showing the equivalent circuit,
`
`Fing shows an example of the back cover of an electronic device designed to
`
`be recharged using an embodiment of the present invention.
`
`Figs.l2(a)-(d) show exploded views ofthe back cover ofFig.1 1,
`
`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 033
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 033
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`

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`Figs.13(a) & (b) show views of a watch that may be recharged in accordance
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`with an embodiment of the invention,
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`Fig.” shows a charging module in accordance with an alternative embodiment
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`of the invention,
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`Fig.15 shows a first
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`layer of a 4x5 winding array for use in a multi-layer
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`embodiment,
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`Fig.16 shows a second layer of a 3x4 winding array for use in conjunction with
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`the layer of Fig.15 in a multi-layer embodiment,
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`Fig.17 shows the layers of Fig.15 and Fig.16 in the two-layer structure,
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`10
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`Fig.18 is simplified version of Fig.15,
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`Fig.19 is a simplified version of Fig.16,
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`Fig.20 is a simplified version of Fig.17,
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`Fig.2! is a plot showing the smoothing effect of the two—layer structure,
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`Fig.22 shows a hexagonal spiral winding,
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`15
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`Fig.23 is a simplified form ofFig.22.
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`Fig.24 shows a single—layer of hexagonal Spiral windings,
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`Fig.25 shows two adjacent hexagonal spiral windings,
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`Fig.26 shows the mmf distribution of the adjacent windings of Fig.25,
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`Fig.27 shows three adjacent hexagonal spiral windings and the peaks and
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`20
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`minima of the flux distribution,
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`Fig.28 shows two overlapped layers of hexagonal spiral windings,
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`Fig.29 shows the location of the peak flux in the structure ofFig.28,
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`Fig.30 corresponds to Fig.29 but also shows the location of the flux minima,
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`Fig.3l shows an embodiment of the invention fanned with three overlapped
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`25
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`layers,
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 034
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 034
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`

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`Fig.32 Corresponds to Fig.3! but shows the location of the flux peaks,
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`Fig.33 is a plot showing the uniformity of the flux distribution along a line,
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`Fig.34 shows a square spiral winding,
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`Fig,35 is a simplified version of Fig.34,
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`5
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`Fig.36 shows a first layer of square spiral windings,
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`Fig.37 corresponds to Fig.36 but shows the location of the flux maxima and
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`minima,
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`Fig.38 shows two overlapped layers of square spiral windings including the
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`locatiOn of the flux maxima and minima,
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`10
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`Fig.39 shows three overlapped layers of square spiral windings including the
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`location of the flux maxima and minima, and
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`Fig.40 shows four overlapped layers of square spiral windings including the
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`location of the flux maxima and minima.
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`lS
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`DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
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`The present
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`invention will now be described in respect of a preferred
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`embodiment
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`in the form of an inductive battery charger for portable electronic
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`equipment such as mobile phones, handheld computers and personal digital assistants
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`(PDA), and devices such as a wireless computer mouse.
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`20
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`Referring firstly to Fig.4, the inductive charger system comprises two modules,
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`a power delivering charger module that contains the primary circuit of a planar
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`isolation transformer and a secondary circuit that is located in the portable electronic
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`equipment to be charged. In this embodiment of the invention, the charger circuit is
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`located within a housing 1 that is formed with a flat charging surface 2. The secondary
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`25
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`circuit is formed in the portable equipment to be charged (in this example a mobile
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 035
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 035
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`

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`phone 3) and the equipment is formed with at least one planar surface. As will be seen
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`from the following description the equipment
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`is charged simply by placing the
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`equipment on the surface so that the planar surface on the equipment is brought into
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`contact with the flat charging surface 2. It is a particularly preferred aspect of the
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`5
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`present invention that the equipment to be charged does not have to be positioned 0n
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`the charging surface in any special orientation. Furthermore. in preferred embodiments
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`of the invention two or more mobile devices may be charged simultaneously on the
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`same charging surface, and/or a device that is designed to be moVed (such as a wireless
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`computer mouse) can be charged while being moved over the charging surface (which
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`10
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`could be integrated into a computer mouse pad). It will also be seen from the following
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`descriptiOn that the energy transfer is “localised" in the sense that energy is only
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`transferred from the charging surface to the device from that part of the charging
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`surface that is directly beneath the device (and pOSsibly to a lesser extent regions
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`adjacent thereto).
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`15
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`Referring in particular to Fig.4(b) the primary charging module comprises a
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`printed circuit board 4 formed with at least one spiral conductive track formed thereon
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`as a primary winding. It will be understood, however. that the primary winding need
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`not necessarily be formed on a PCB and could be formed separately. Preferably. as will
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`be described further below, there are in fact a plurality of such spiral tracks disposed in
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`20
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`an array as shown in Fig.4(c). Beneath the PCB 4 (ie the side of the PCB away from the
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`charging surface) is provided EMI shielding comprising firstly a ferrite sheet 5 adjacent
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`the PCB 4, and then a conductive sheet 6 which in this example may be a copper sheet.
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`Beneath the copper sheet 6 may be provided any suitable form of substrate material 7,
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`eg a plastics material. Above the PCB 4 may be provided a sheet of insulating material
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`25
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`8 which forms the charging surface. Preferably the PCB 4, the EMI shielding sheets 5,6,
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 036
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 036
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`

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`the substrate 7 and the insulating cover sheet 8 may also be generally the same size and
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`shape. for example rectangular, so as to form the primary charging module with the
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`charging surface being large enough to accommodate at least one, and more preferably
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`two or more, devices to be charged. Figs.5(a) and (b) also show the structure of the
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`charging module without the cover sheet and without any devices to be charged thereon
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`for the sake of clarity.
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`As shown in Fig.4. the primary transformer circuit module transmits electrical
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`energy at high freQuency through a flat charging surface that contains the primary
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`transformer windings. The secondary winding is also planar and is located in the
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`portable electronic equipment and couples this energy, and a rectifier within the
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`portable equipment rectifies the highvfrequency secondary AC voltage into a DC
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`voltage for charging the battery inside the portable equipment either directly or via a
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`charging circuit. The rectified DC voltage is applied to the battery via mechanical
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`contacts provided in an integrated back cover as will be described further below. No
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`physical electrical connection between the primary charger circuit and the portable
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`electronic equipment is needed.
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`The primary charger circuit has (1) a switched mode power electronic circuit. (2)
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`the primary side of a planar transformer that consists of a group of primary windings
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`connected in series or in parallel or a combination of both, (3) an EMI shield and (4) a
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`flat interface surface on which one or more portable electronic devices can be placed
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`and charged simultaneously. The schematic of the primary charger system is shown in
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`10
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`15
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`20
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`Fig.5 without the insulating cover.
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`The battery charging system can be powered by AC or DC power sources. If the
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`power supply is the AC mains, the switched mode power electronic circuit should
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`25
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`perform a low-frequency (50 or 60Hz) AC to DC power conversion and then DC to
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 037
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 037
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`

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`10
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`high-frequency (typically in the range from 20kHz to lOMHz) AC power conversion.
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`This high-frequency AC voltage will feed the primary planar windings of the primary
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`charger circuit. If the power supply is a battery (eg. a car battery), the switched mode
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`power supply should perform a DC to high-frequency AC power conversion. The high-
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`frequency voltage is fed to the primary windings of the planar transformer.
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`Preferably, the charger should be able to charge one or more than one items of
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`portable electronic equipment at the same time. In order to achieve such a function, the
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`AC magnetic flux experienced by each item of portable equipment placed on the
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`charging surface should be as even as possible. A standard planar spiral winding as
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`10
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`shown in Fig.6(a) is not suitable to meet this requirement because its flux distribution is
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`not uniform as shown in Fig.6(b) when the winding is excited by an AC power source.
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`The reason for such non-uniform magnetic flux distribution is that the number of turns
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`in the central region of the single spiral winding is largest. As the magnitude of the
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`magnetic flux and the magnetomctive force (aunt) is preponional to the product of the
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`15
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`number of turn and the current in the winding, the magnetic flux is highest in the centre
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`of the winding.
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`One method to ensure uniform magnetic flux or mmf distribution is to use a
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`concentric primary winding with a planar magnetic core as shown in Fig.7(a). This
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`magnetic core-based approach allows the magnetic flux to concentrate inside the core
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`20
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`and typical magnetic flux distribution is Show in Fig.7(b). In general, the flat charging
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`interface surface of the primary charger should be larger than the total area of the
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`portable electronic equipment.
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`In order to ensure that more than one item of portable electronic equipment can
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`be placed on the flat charging surface and charged simultaneously, a second and more
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`25
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`preferred method preposed is to ensure that the magnetic flux distribution experienced
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 038
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 038
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`

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`11
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`by each items of portable electronic equipment is as uniform as possible. This method
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`can be realized by using a "distributed" primary planar transformer winding may
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`structure as shown in Fig.8. This planar winding array consists of many printed Spiral
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`windings formed on the PCB. These printed Spiral windings can be hexagonal. circular,
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`square or rectangular spirals, and can be connected in series,
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`in parallel or a
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`combination of both to the high-frequency AC voltage generated in the power supply in
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`the primary charger circuit. The array should comprises relatively closely spaced coils
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`so as to be able to generate the required near-uniform magnetic flux distribution, as an
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`array of widely spaced apart coils may not generate such a near—uniform field.
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`Fig.9(a)
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`shows a practical example with the transformer winding array
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`connected in series so that all the fluxes created in the windings point to the same
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`direction. Fig.9(b) show the measured flux distribution of one planar transformer when
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`the windings in the transformer array are connected in series. This measurement
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`confirms the near uniform magnetic flux distribution of the array structure. Comparison
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`of Fig.6(b) and Fig.9(b) confirms the improvement of the uniform magnetic field
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`distribution using the transformer array structure. In addition, this transformer array
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`structure provides for the possibility of multiple primary transformer windings being
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`provided for localized charging as will now be explained.
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`The primary transformer windings can also take the form of a combination of
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`series and parallel connections if desired. Such an arrangement allows the charging
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`surface to be divided into various charging regions to cater for different sizes of the
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`secondary windings inside the portable electronic equipment. Fig.10(a) illustrates this
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`localized charging zone principle. Assume that the transformer array is divided into 4
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`zones (A, B, C, and D). The transformer windings within each zone are connected in
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`series to form one primary winding group with the distributed magnetic flux feature.
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`10
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`15
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`20
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`25
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 039
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 039
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`

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`12
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`There will be four primary windings in the equivalent cirCuit as shown in Fig.1 0(a). if
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`the portable electronic equipment is placed on Zones A and B as shown in Fig.10(b),
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`the equivalent electrical circuit
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`is shown in Fig.10(c). Only the parallel primary
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`transformer winding groups for Zones A and B are loaded because they can sense a
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`nearby Secondary winding circuit in the portable electronic equipment. Therefore, they
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`will generate magnetic flux in Zones A and B. Primary transformer windings C and D
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`are not loaded because they have no secondary transformer circuit close to them and
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`10
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`15
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`their equivalent secondary circuits are simply an open-circuit (Fig.lO(e)). As a result,
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`power transfer between the primary charger circuit and the secondary windings inside
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`the portable electronic equipment takes place basically through the coupled regions
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`(areas) of the charging interface surface covered by the portable electronic equipment.
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`The non-covered area of the charging surface will transfer virtually no energy. This
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`special design avoids unnecessary electromagnetic interference. A further advantage of
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`this localised energy transfer concept, is that it enables a movable device (such as a
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`wireless computer mouse) to be continually charged as it mOVes over the charging
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`surface. In the case of a wireless computer mouse, for example, the primary charging
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`circuit could be integrated into a mousepad and the mouse may be charged as it moves
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`over the mousepad.
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`The back cover of the portable electronic equipment is a detachable back cover
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`20
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`that covers the battery and which may be removed when the battery is replaced. In
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`' preferred embodiments of the present
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`invention,
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`this back cover has a built-in
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`secondary planar transformer winding, a diode rectifier circuit and preferably a thin
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`BMI shield as shown in Fig.12(b) & (c). When the back cover side of the portable
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`equipment is placed near the flat charging surface of the primary charger circuit, this
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`25
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`secondary winding couples the energy train the nearby primary transformer winding or
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`Momentum Dynamics Corporation
`Exhibit 1 01 9
`Page 040
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 040
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`

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`l3
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`windings. The rectifier circuit rectifies the coupled AC voltage into a DC voltage for
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`charging the battery. This rectifier circuit also prevents the battery from discharging
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`into the secondary winding. In order to avoid induced circuit from circulating in other
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`metal parts inside portable electronic circuit, it is preferable to include a thin EM]
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`5
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`shield as part of the integrated back cover structure as shown in Fig.12. This EM!
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`shield can be a thin piece of ferrite material (such as a flexible ferrite sheet developed
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`by Siemens) or ferrite sheets, or more preferably a combination of a ferrite sheet and
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`then a thin copper sheet.
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`It will thus be seen that, at least in its preferred forms, the present invention
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`10
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`provides a new planar inductive battery charger for portable electronic equipment such
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`as mobile phones, handheld computers, personal data assistant (FDA) and electronic
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`watches, and wireless computer mice. The inductive charger system consists of tho
`
`modules, including (1) a power delivering charger circuit that contains the primary
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`circuit of a planar isolation transformer and a flat charging surface and (2) a separate
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`15
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`secondary transformer circuit
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`that consists of a printed winding, a rectifier and
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`preferably a thin EM! shield and which is located in the portable electronic equipment
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`to be charged.
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`An advantage