`
`(30) Priority Data:
`(33) GB
`(32) 10.06.2002
`(31) 0213374
`
`
`
`
`
`
`
`
`(22) Date of Filing:
`
`18.11.2002
`
`(71) Applicant(s):
`Clty University of Hong Kong
`(Incorporated In Hong Kong)
`Tat Chee Avenue, Kowloon Tong,
`Kow loon, Hong Kong
`
`(72) Inventor(s):
`Ron Shu-Yuen Hui
`
`(52) UK CL (Edition V ):
`H2H HAM HBCH
`HiT T1C T1F 712 T7A5 T7C5 T9
`U1S $2199 $2215
`
`(56) Documents Cited:
`US 6008622 A
`
`US 5959433 A
`
`(58) Field of Search:
`UK CL (Edition V ) H1T, H2H
`INT CL’ HO1F HO2J
`Other: Online: WPI, PAJ, EPODOC
`
`
`
`ua UK Patent Application 9GB an2 389 720 as) A
`
`17.12.2003
`(43) Date of A Publication
`
`(51)
`INT CL’:
`(21) Application No:
`0226893.6
`HO1F 38/14, HO2J 7/02
`
`
`electronic device 3 includes a secondary winding.
`
`(74) Agent and/or Addressfor 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. 4c). 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
`
`FIG.4(b)
`
`7
`
`VO¢L68E¢AD
`
`At least one drawing originally filed was informal and the print reproduced here is taken fromalaterfiled formal copy.
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 001
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 001
`
`
`
`124
`
`
`
` charger
`
`FIG.1 (PRIOR ART)
`
`Magnetic
`Magnetic
`core for
`core for
`primary
`
`winding [eee|[eee] a secondaryoo
`winding
`
`
`
`:
`Primary
`winding
`
`_
`
`ee
`
`[eee]
`
`A
`
`Secondary
`,
`winding
`
`Air gap
`
`FIG.2 (PRIOR ART)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 002
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 002
`
`
`
`---— Ferrite Plate
`
`
`~— Copper Sheet
`
`
`
`
`_, Thermally Conductive
`Insulating Layer
`
`5 j
`
`~ Polyurethane-coated
`Insulated Copper Wires
`
`
`
`i _'
`»
`
`; ii “ Dielectnc Laminate
`
`
`
`IG.4(b)
`
`a F
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 003
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 003
`
`
`
`FIG.4(c)
`
`FIG.5(a)
`
`FIG.5(b)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 004
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 004
`
`
`
`
`
`
`4 /
`
`tv —I
`
`
`(dBuV) >
`
`FIG.6(a)
`
`Magnitude
`
`Yomm) 1b 20
`
`oO
`0Ximm>
`
`FIG.6(b)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 005
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 005
`
`
`
`5/21
`
`FIG.7(a)
`
`Magnetic
`flux
`magnitude
`
`distance
`
`FIG.7(b)
`
`
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 006
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 006
`
`
`
`lol
`
`tr —
`
`
`
`FIG.9a)
`
`dBuV
`130
`
`125
`
`120
`
`Magnitude(dBuV)
`
`a 15
`
`Wy 20
`
`40 OBO 100
`X(mm)
`
`FO
`
`FIG.9(b)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 007
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 007
`
`
`
`FIG.10(a)
`
`FIG.10(b)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 008
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 008
`
`
`
`
`
`6( 27]
`
`Energy coupled zones
`
`Battery load
` To
`
`High-
`frequency
`AC voltage
`source
`
`Secondary
`winding
`
`Groups of
`pnmary windings
`
`FIG.10(c)
`
`
`
`Integrated
`secondary charger
`system
`
`Mechanical contacts for
`connection with the battery pack
`
`FIG.S 1
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 009
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 009
`
`
`
`a/ri
`
`FIG. 12(a)
`
`PCB winding of the
`_ secondary charger
`system
`
`“> EMI shield(ferrite sheet)
`
`connection with the battery pack
`
`FIG. 12(b)
`
`PCB winding ofthe
`aeeees secondary charger
`system
`
`“~ EMI shield(coppersheet)
`EMI shield(ferrite sheet) BMY] shield(coppersheet)
`
`~ Rectifier circuit
`
`NX Mechanical contacts for
`connection with the battery pack
`
`FIG.12(c)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 010
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 010
`
`
`
`10427
`
`- secondary charger
`system
`
`EMIshield(ferrite sheet)
`
` PCB windingofthe
`
`EMIshield(copper sheet)
`
`MN
`“\ Mechanical contacts for
`connection with the battery pack
`
`FIG.12(d)
`
`cover
`
`Non-metallic
`
`FIG.13(a)
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 011
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 011
`
`
`
`V/2i
`
`eeeCS Non-metallic cover
`
`—
`
`+ PCB winding with rectifier circuitf
`
`eee C4
`
`Mechanical-
`contacts
`
`+>
`
`<a 23 EMI smeld(ferrite sheet)
`
`Co) __+22EMIshield(coppersheet)
`
`Rechargeable —->
`battery
`
`“U
`
`FIG. 13(b)
`
`OG
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 012
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 012
`
`
`
`2/1 |
`
`31
`
`Cable
`connection
`
`Connection to
`
`\
`the powersource
`
`Electronic
`charging circuit
`
`EMIshield
`
`Charging surface
`consisting of (1)
`insulation top cover,(2)
`planar PCB primary
`windings and (3) bottom
`
`32
`
`FIG.14
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 013
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 013
`
`
`
`BL 2]
`
`
`
` aeEo
`
`
`
`
`
`FIG.15
`
`
`
`FIG.16
`
`s CorExnib1019
`
`Page 014
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 014
`
`
`
`4/27
`
`
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 015
`
`
`
`5 {27
`
`Lae en ee ee we dhe ee wee ew dee eee we eee dhe ee ee we eee 2
`M4
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`PTs ella
`ve
`teusw
`s
`un
`yir
`
`an
`
`"r
`
`FIG.19
`
`Seuw
`t
`
`"u
`
`FIG.20
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 016
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 016
`
`
`
`(o/27
`
`Magnetic field magnitude distribution 1n the first layer
`
` Distance
`
`
`
`MagneticField
`
`magnitude
`
`1eld4
`
`Magnetic|
`
`magnitude
`
`7
`
`‘
`
`Magnetic field magnitude distnbution in the second layer
`-—
`ross‘
`
`one
`
`‘
`
`¢
`
`f
`
`ote
`
`é
`
`‘
`
`Distance
`
`*|Resultant magnetic field magnitude distribution in the multi-layer structurefy Distance
`
`MagneticFeld
`
`magnitude
`
`FIG.21
`
`©)
`
`FIG.22
`
`FIG.23
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 017
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 017
`
`
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 018
`
`
`
`FIG.25
`
`FIG.26
`
`mmf
`
`] 0
`
`.5,
`
`0
`
`P
`
`Vvce
`
`FIG,27
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 019
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 019
`
`
`
`\A/21
`
`8OFA
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 020
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 020
`
`
`
`LO 21
`
`
`
`FIG.29
`
`or
`Momentum Dynamics C:
`Exhi
`
`poration
`bit 1019
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 021
`
`
`
`a (2!
`
`FIG.30
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 022
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 022
`
`
`
`2/27
`
`pseucoe%..
`
`,7&6
`
`esanayw
`soeeee
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`é
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`seewegerties»
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`<wenewygrits
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`waeweneeds
`
`oemeeneae
`
`
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`PeenreanS
`
`temreenndl
`
`wonenandt
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 023
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 023
`
`
`
`
`
`
` pz}et
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 024
`
`
`
`zy /2T
`
`
`
`Distance
`
`FIG.33
`
`FIG.34
`
`FIG.35
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 025
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 025
`
`
`
`LLL
`LL
`eae
`tL
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 026
`
`
`
`
`
`FIG.38
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 027
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 027
`
`
`
`
`Cote beatSpar
`
`
`
`
`FIG.39
`
`afatatabateSeesete
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 028
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 028
`
`
`
`2389720
`
`PLANAR INDUCTIVE BATTERY CHARGER
`
`FIELD OF THE INVENTION
`
`This invention relates to a battery charger, andin particular to a battery charger
`
`having a planar surface on which one or more battery powered devices may be placed
`
`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
`
`15
`
`powered by batteries. In many cases, rechargeable batteries are preferred because of
`
`environmental
`
`and economical concems. 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. US6,356,049,
`
`US6301,128, US6,118,249, also all deacribe various forms of inductive chargers. These
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 029
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 029
`
`
`
`inductive type chargers, however, use traditional transformer designs with windings
`
`wound around fertite 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 al in “A new contactless 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.
`
`Asillustrated further below, the magnitude of the magnetic field in the centre ofthe
`
`core of a spiral winding is highest and decreases from the centre. This meansthatif 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.
`
`SUMMARYOF 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 formed
`
`with a planar charging surface adapted to receive an electronic device to be charged,
`
`wherein said primary charging circuit includes the primary winding ofa 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 1019
`Page 030
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 030
`
`
`
`ssid winding opposite from said planar charging surface, and wherein said electronic
`
`device is formed with a secondary winding.
`
`In a preferred embodimentthe primary winding is formed on a planar printed
`
`circuit board,
`
`Preferably the magnetic flux generated by the primary winding is substantially
`unifornn over at least a majorpart ofthe planar charging surface. In this way the precise
`
`position and orientation of the electronic device on the charging surface is notcritical.
`
`To achieve this the charging module may comprise a plurality of primary windings,
`which maypreferably be disposed in a regular array.
`
`10
`
`provided with
`is
`the primary winding
`embodiment
`a preferred
`In
`electromagnetic shielding on the side of said winding opposite from said planar
`charging surface. This shielding may include a sheet of fetrite material, and more
`
`preferably also may further include a sheet of conductive material such as copper or
`
`aluminium
`
`15
`
`It is an advantage of the present invention that in preferred embodiments the
`planar charging surface maybe large cnough 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
`
`20
`
`simultaneously. For example the planar charging surface may be divided into a
`plurality of charging regions, which regions may be defined by providinga plurality of
`. primary transformer windings arranged in a regular array and connecting the windings
`in groups to define said charging regions. A further advantage ofthe 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
`
`25
`
`which is designed to be moved such as a wireless computer mouse
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 031
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 031
`
`
`
`C*
`
`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 receivingelectrical energy
`
`from a battery charger, and electromagnetic shielding between the winding and the
`
`10
`
`major electronic components ofsaid device.
`
`Preferably the shielding comprises a sheet of ferrite material and a sheet of
`
`conductive material such as copper.
`
`Preferably the windingis formed integrally with a back coverofsaid device.
`
`An important aspect of the present
`
`invention is that it provides a battery
`
`15
`
`charging system that employsa 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 secondary coil located in the device being
`
`charged. In other words, when a device is placed an 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 ofthe invention will now be described by way of example
`
`25
`
`and with reference to the accompanying drawings, in which:-
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 032
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 032
`
`
`
`Fig.1 is a schematic view of a conventional ptior art battery charger with direct
`
`electrical connection,
`
`Fig.2 is a schematic view of a conventional magnetic core-based transformer as
`
`usedin priorart inductive battery charger systems,
`
`Fig.3 is a schematic view ofa planar transformer with shielding,
`
`Figs.4(a)-(c) are (a) a perspective view of a battery charger system according to
`
`an embodiment ofthe present invention, (b) a view similar to (a) but showing
`
`the structure ofthe primary charging system, and (c) a view similar to (a) and (b)
`
`but showingthe top cover removed forclarity,
`
`10
`
`Figs.5(a) & (b) show the structure of the primary charger with the top cover
`
`removed forclarity, 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 ofa single spiral winding,
`
`Figs.7(a) & (b) illustrate the use of a magnetic core to control magnetic field
`
`15
`
`distribution,
`
`Fig.8 shows an embodimentof 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(c) showing the equivalent circuit,
`
`Fig.l] shows an example of the back cover of an electronic device designed to
`
`be recharged using an embodimentofthe present invention,
`
`Figs.12(a)-(d) show exploded views ofthe back cover ofFig.11,
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 033
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 033
`
`
`
`Figs.13(a) & (b) show views of a watch that may be recharged in accordance
`
`with an embodimentof the invention,
`
`Fig. 14 shows a charging module in accordance with an alternative embodiment
`
`of the invention,
`
`Fig.15 shows a first
`
`layer of a 4x5 winding array for use in a multi-layer
`
`embodiment,
`
`Fig.16 shows a secondlayer of a 3x4 windingarray for use in conjunction with
`
`the layer of Fig.15 in a multi-layer embodiment,
`
`Fig.17 showsthe layers of Fig.15 and Fig.16 in the two-layer structure,
`
`Fig.18 is simplified version of Fig.15,
`
`Fig.19 is a simplified version of Fig.16,
`
`Fig.20 is a simplified version of Fig.17,
`
`Fig.21 is a plot showing the smoothingeffect of the two-layer structure,
`
`Fig.22 showsa hexagonalspiral winding,
`
`15
`
`Fig.23 is a simplified form of Fig.22,
`
`Fig.24 shows a single-layer of hexagonal spiral windings,
`
`Fig.25 shows two adjacent hexagonal spiral windings,
`
`Fig.26 shows the mmfdistribution of the adjacent windings ofFig.25,
`
`Fig.27 shows three adjacent hexagonal spiral windings and the peaks and
`
`20
`
`minima ofthe flux distribution,
`
`Fig.28 shows two overlapped layers of hexagonal spiral windings,
`
`Fig.29 showsthe location of the peak flux in the structure ofFig.28,
`
`Fig.30 corresponds to Fig.29 but also showsthe location ofthe flux minima,
`
`Fig.31 shows an embodiment of the invention formed with three overlapped
`
`25
`
`layers,
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 034
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 034
`
`
`
`Fig.32 correspondsto Fig.31 but shows the location of the flux peaks,
`
`Fig.33 is a plot showing the uniformity ofthe flux distribution along a line,
`
`Fig.34 shows a square spiral winding,
`
`Fig.35 is a simplified version of Fige.34,
`
`Fig.36 showsa first layer of square spiral windings,
`
`Fig.37 corresponds to Fig.36 but shows the location of the flux maxima and
`
`minima,
`
`Fig.38 shows two overlapped layers of square spiral windings including the
`
`location of the flux maxima and minima,
`
`Fig.39 shows three overlapped layers of square spiral windings including the
`
`location of the flux maxima and minima, and
`
`Fig.40 shows four overlapped layers of square spiral windings including the
`
`location of the flux maxima and minima.
`
`15
`
`DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
`
`The present
`
`invention will now be described in respect of a preferred
`
`embodiment
`
`in the form of an inductive battery charger for portable electronic
`
`equipment such as mobile phones, handheld computers and personal digital assistants
`
`(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,
`
`a power delivering charger module that contains the primary circuit of a planar
`
`isolation transformer and a secondary circuit that is located in the portable electronic
`
`equipment to be charged. In this embodimentof the invention, the charger circuit is
`
`located within a housing 1 that is formed with a flat charging surface 2. The secondary
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`circuit is formed in the portable equipment to be charged (in this example a mobile
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 035
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 035
`
`
`
`phone 3) and the equipmentis formed with at least one planar surface. As will be seen
`
`from the following description the equipment
`
`is charged simply by placing the
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`equipmicnt on the surface so that the planar surface on the equipmentis brought into
`
`contact with the flat charging surface 2. It is a particularly preferred aspect of the
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`present invention that the equipment to be charged does not have to be positioned on
`
`the charging surface in any special orientation. Furthermore, in preferred embodiments
`
`of the invention two or more mobile devices may be charged simultaneously on the
`
`same charging surface, and/or a device that is designed to be moved (such as a wireless
`
`computer mouse) can be charged while being moved over the charging surface (which
`
`10
`
`could be integrated into a computer mousepad).It will alsa be seen from the following
`
`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).
`
`1s
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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
`
`as a primary winding. It will be understood, however, that the primary winding need
`
`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
`an array as shown in Fig.4(c). Beneath the PCB4(ie the side ofthe PCB away from the
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`charging surfacc) is provided EMI shiclding comprising firstly a ferrite sheet 5 adjacent
`
`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 formsthe charging surface. Preferably the PCB 4, the EMI shielding sheets 5,6,
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 036
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 036
`
`
`
`the substrate 7 and the insulating cover sheet 8 may also be generally the same size and
`
`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 ofthe
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`charging module without the cover sheet and without any devicesto be charged thereon
`
`for the sakeofclarity.
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`As shownin 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
`
`10
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`portable electronic equipment and couples this energy, and a rectifier within the
`
`portable equipment rectifies the high-frequency secondary AC voltage into 2 DC
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`voltage for charging the battery inside the portable equipmenteither directly or via a
`
`charging circuit. The rectified DC voltage is applied to the battery via mechanical
`
`contacts provided in an integrated back cover as will be described further below. No
`
`15
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`physical electrical connection between the primary charger circuit and the portable
`
`electronic equipmentis needed.
`
`The primary charger circuit has (1) a switched mode powerelectronic circuit, (2)
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`the primary side of a planar transformer that consists of a group of primary windings
`
`connectedin series or in parallel or a combination of both, (3) an EMI shield and (4) a
`
`20
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`flat interface surface on which one or more portable electronic devices can be placed
`
`and charged simultaneously. The schematic ofthe primary charger system is shown in
`
`Fig.5 without the insulating cover.
`
`The battery charging system can be powered by AC or DC power sources.If the
`
`power supply is the AC mains, the switched mode power electronic circuit should
`
`25
`
`perform a low-frequency (50 or 60Hz) AC to DC powerconversion and then DC to
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 037
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 037
`
`
`
`10
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`high-frequency(typically in the range from 20kHz to 10MHz) AC power conversion.
`This high-frequency AC voltage will feed the primary planar windings of the primary
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`charger circuit. If the power supplyis a battery (e.g, a cat battery), the switched mode
`
`power supply should perform a DCto high-frequency AC power conversion. The high-
`
`frequency voltageis 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 oneitems of
`
`portable electronic equipmentat the sametime. 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
`
`charging surface should be as even as possible. A standard planar spiral winding as
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`10
`
`shownin Fig.6(a) is not suitable to meetthis requirernent becauseits flux distributionis
`
`not uniform as shown in Fig.6(b) when the windingis excited by an AC powersource.
`
`The reason for such non-uniform magnetic flux distribution is that the number of tums
`
`in the central region ofthe single spiral winding is largest. As the magnitude of the
`
`magnetic flux and the magnetomative force (mmf) is proportional to the productof the
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`15
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`number of turn and the currentin the winding, the magnetic flux is highest in the centre
`
`of the winding.
`
`One method to ensure uniform magnetic flux or mmfdistribution 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
`
`20
`
`and typical magnetic flux distribution is shown in Fig.7(b). In general, the flat charging
`
`interface surface of the primary charger should be larger than the total area of the
`
`portable electronic equipment.
`
`In orderto ensure that more than one item of portable electronic equipment can
`
`be placed on the flat charging surface and charged simultaneously, a second and more
`
`25
`
`preferred method proposed js to ensure that the magnetic flux distribution experienced
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`Momentum Dynamics Corporation
`Exhibit 1019
`Page 038
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 038
`
`
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`11
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`by each itemsofportable electronic equipment is as uniform as possible, This method
`
`can be realized by using a “distributed” primary planar transformer winding array
`
`structure as shown in Fig.8. This planar winding array consists of many printed spiral
`
`windings formed on the PCB. These printed spiral windingscan be hexagonal, circular,
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`square or rectangular spirals, and can be connected in series,
`
`in parallel or a
`
`combination ofboth to the high-frequency AC voltage generated in the power supply in
`
`the primary charger circuit. The array should comprisesrelatively closely spaced coils
`
`So as to be able to generate the required near-uniform magnetic flux distribution, as an
`
`array of widely spaced apart coils may not generate such a near-uniform field.
`
`10
`
`Fig.9(a)
`
`shows a practical example with the transformer winding array
`
`connected in series so that all the fluxes created in the windings point ta the same
`
`direction. Fig.9(b) show the measured flux distribution of one planar transformer when
`
`the windings in the transformer array are connected in series. This measurement
`
`confirms the near uniform magnetic flux distribution ofthe array structure. Comparison
`
`15
`
`of Fig.6(o) and Fig.9(b) confirms the improvement of the uniform magnetic field
`
`distribution using the transformer array structure, In addition, this transformer array
`
`structure provides for the possibility of multiple primary transformer windings being
`
`provided for localized charging as will now be explained.
`
`The primary transformer windings can also take the form of a combination of
`
`20
`
`series and parallel connections if desired, Such an arrangement allows the charging
`
`surface to be divided into various charging regions to cater for different sizes of the
`
`secondary windings inside the portable electronic equipment. Fig.10(a) illustrates this
`localized charging zone principle. Assume that the transformer array is divided into 4
`
`zones (A, B, C, and D), The transformer windings within each zone are connected in
`
`25
`
`series to form one primary winding group with the distributed magneticflux feature.
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 039
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 039
`
`
`
`12
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`There will be four primary windings in the equivalent circuit as shownin Fig.10(c).If
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`the portable electronic equipment is placed on Zones A and B as shown in Fig.10(b),
`
`the equivalent clectrical circuit
`
`is shown in Fig.10(c). Only the parallel primary
`
`transformer winding groups for Zones A and B are loaded because they can sense a
`
`nearby secondary windingcircuit in the portable electronic equipment. Therefore, they
`
`will generate magnetic flux in Zones A and B. Primary transformer windings C and D
`
`are not loaded because they have no secondary transformercircuit close to them and
`
`their equivalent secondary circuits are simply an open-circuit (Fig.10(c)). As a result,
`
`powertransfer between the primary charger circuit and the secondary windings inside
`
`10
`
`the portable electronic equipment takes place basically through the coupled regions
`
`(areas) of the charging interface surface covered by the portable electronic equipment.
`
`The non-covered area of the charging surface will transfer virtually no energy. This
`
`special design avoids unnecessary electromagnetic interference. A further advantage of
`
`this localised energy transfer concept, is that it enables a movable device (such as a
`
`15
`
`wireless computer mouse) to be continually charged as it moves over the charging
`
`surface. In the case of a wireless computer mouse, for example, the primary charging
`
`circuit could be integrated into a mousepad and the mouse may be charged as it moves
`
`over the mousepad.
`
`The back coverofthe portable electronic equipmentis a detachable back cover
`
`20
`
`that covers the battery and which may be removed whenthe battery is replaced. In
`
`' preferred embodiments of the present
`
`invention,
`
`this back cover has a built-in
`
`secondary planar transformer winding, a diode rectifier circuit and preferably a thin
`
`EMIshield as shown in Fig.12(b) & (c). When the back cover side of the portable
`
`equipment is placed near the flat charging surface of the primary chargercircuit, this
`
`25
`
`secondary winding couples the energy from the nearby primary transformer winding or
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 040
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 040
`
`
`
`13
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`windings, The rectificr circuit rectifies the coupled AC voltage into a DC voltage for
`
`charging the battery. This rectifier circuit also prevents the battery from discharging
`
`into the secondary winding. In order to avoid induced circuit from circulating in other
`
`metal parts inside portable electronic circuit, it is preferable to include a thin EMI
`
`shield as part of the integrated back cover structure as shown in Fig.12, This EMI
`
`shield can be a thin piece of ferrite material (such as a flexible ferrite sheet developed
`
`by Siemens) or ferrite sheets, or more preferably a combination ofa ferrite sheet and
`
`then a thin copper sheet,
`
`It will thus be seen that, at least in its preferred forms, the present invention
`
`10
`
`provides a new planar inductive battery charger for portable electronic equipment such
`
`as mobile phones, handheld computers, personal data assistant (PDA) and electronic
`
`watches, and wireless computer mice. The inductive charger system consists of two
`
`modules, including (1) a power delivering charger circuit that contains the primary
`
`circuit of a planar isolation transformer and a flat charging surface and (2) a separate
`
`18
`
`secondary transformer circuit
`
`that consists of a printed winding, a rectifier and
`
`preferably a thin EMIshield and which is located in the portable electronic equipment
`
`to be charged.
`
`An advantage of the present invention, at least in preferred forms,is that the
`
`primary charger circuit system has the primary side of a planar transformer andaflat
`
`20
`
`interface surface on which one or more portable electronic devices can be placed and
`
`charged simultaneously, The secondary circuit can be integrated into the back cover of
`
`the portable electronic device or separately placed inside the electronic device, The
`
`invention also extends to a back cover design with an in-built secondary circuitfor the
`
`portable equipment, The secondary winding of the planar transformer can be EMI
`
`25
`
`shielded and integrated into the back cover adjacent to the battery in the portable
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 041
`
`Momentum Dynamics Corporation
`Exhibit 1019
`Page 041
`
`
`
`14
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`electronic device. As long as the ba