United States Patent
`
`[19]
`
`[11] Patent Number:
`
`Goto
`
`[45] Date of Patent:
`
`5,600,225
`Feb. 4, 1997
`
`ACTA AYA
`
`US005600225A
`
`[54] NONCONTACTING CHARGING DEVICE
`
`Attorney, Agent, or Firm—Scully, Scott, Murphy & Presser
`
`[57]
`
`ABSTRACT
`
`A non-contacting charging device is disclosed which per-
`forms charging in which electric power of a charger 1 is
`supplied without direct contactto a storage battery 210, and
`which includes in the charger 1 a primary coil 103 and
`circuits 104, 105 for supplying AC powerto the primary
`coil, and also includes in the radio communication device
`having a storage battery 210, a secondary coil 212 that
`couples electromagnetically with the primary coil 103 and a
`circuit 211 for supplying the induced current power gener-
`ated in the secondary coil to the storage battery as charging
`power. This device is provided with halt signal generating
`circuits. 203, 209, and 214 for generating a halt signal that
`commandsa halt of supply of AC powerto the primary coil,
`and a halting circuit for halting supply of AC powerto the
`primary coil in response to a halt signal, the halt signal
`generating circuit being provided in the radio communica-
`tion device. If it is necessary to makeor receive a call during
`10/1989 Sakamoto et al. oo...ete 320/2
`4,873,677
`charging of the radio communication device, a halt signal is
`4,942,352—T/1990 Sano .u.scssccrsssrerersesseeensensesssenseeses 320/2
`generated on the radio communication device side to halt
`charging, thereby eliminating the attractive force caused by
`the electromagnetic induction in effect between the radio
`communication device and the charger, and allowing
`removal of the radio communication device from the charger
`with a minimum ofeffort.
`
`{76]
`
`[21]
`
`[22]
`
`[30]
`
`Inventor: Masataka Goto, c/o NEC Corporation,
`7-1, Shiba 5-chome, Minato-ku, Tokyo,
`Japan
`
`Appl. No.: 492,628
`
`Filed:
`
`Jun. 20, 1995
`
`Foreign Application Priority Data
`
`Jun. 30, 1994
`
`[JP]
`
`Japan,
`
`sscvisissserscoseivesicassvencesiens: 6-171722
`
`[51] Unt. Cho oeeeeeeeesesseseeeeenee HOIM 10/44; HO2J 7/00
`[52] US.) ssassscmmccsnnesenamacncne 320/2; 320/21
`
`[58] Field of Search ....00 320/2, 21; 329/443
`
`{56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`FOREIGN PATENT DOCUMENTS
`
`2-280631
`4-217824
`1180168
`
`Japan .
`11/1990
`Japan .
`8/1992
`2/1970 United Kingdom .
`
`Primary Examiner—Peter $. Wong
`Assistant Examiner—Patrick B. Law
`
`7 Claims, 2 Drawing Sheets
`
`TRX
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`BASEBAND
`CIRCUIT
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`1
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`ANKER 1013
`ANKER1013
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`1
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`

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`U.S. Patent
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`Sheet 1 of 2
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`Feb. 4, 1997
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`5,600,225 FIG. 4
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`2
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`

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`U.S. Patent
`
`Feb. 4, 1997
`
`Sheet 2 of 2
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`5,600,225
`
`202
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`205
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`KEYBOARD
`CONTROL
`CIRCUIT
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`RECEIVING
`ELEMENT
`CIRCUIT
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`OSCILLATING
`CIRCUIT
`CONTROL SECTION
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`210
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`AC-DC
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`CONVERSION
`CIRCUIT
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`EMITTING
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`CIRCUIT
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`5,600,225
`
`1
`NONCONTACTING CHARGING DEVICE
`
`BACKGROUND OF THE INVENTION
`
`1. Field of the Invention
`
`The present invention relates to a charging device for a
`radio communication device, and particularly to a charging
`device for charging, in an clectrically noncontacting state, a
`radio communication device such as a storage-battery-
`equipped radiotelephone.
`2. Description of the Related Art
`Charging devices have been suggested recent years for
`charging chargeable storage batteries installed in radio com-
`munication devices such as radiotelephonesthat are capable
`of charging without being electrically connected to the
`radiotelephone. One example of such a device is a noncon-
`tacting charging device disclosed in Japanese Patent Laid-
`open 280631/90.In this charging device, a battery chargeris
`provided with a primary coil to which an alternating current
`signal is supplied, while a radiotelephoneis provided with a
`secondary coil which couples electromagnetically with the
`primary coil and which is connected to a charging circuit for
`a storage battery. By bringing the radiotelephone into prox-
`imity with the charger and supplying the primary coil with
`alternating current of prescribed voltage and frequency, an
`induced electromotive force is generated in the secondary
`coil to serve to charge the storage battery of the radiotele-
`phone.
`In this charging device of the prior art, as the mutual
`induction coefficient between the primary and secondary
`coils is increased to raise an efficiency of an electric power
`supply to the storage battery of the radiotelephone,
`the
`electromagnetic attraction working between the two coils
`increase nearly in proportion to the mutual induction coef-
`ficient. This attractive force, however, adversely makes it
`difficult to lift lightly the radiotelephone from charger when
`it is necessary to makea call or to receive an incoming call
`during charging.
`In such a case, charging is stopped in a chargerofthe prior
`art by pulling the power cord of an external power source
`connected to the charger from the commercial powersocket.
`This necessity to pull the cord when lifting the radiotele-
`phone from the charger is a nuisance, particularly when the
`radio telephone must be picked up quickly to receive an
`incoming call while using the charging device. However,if
`the powerof the charger is decreased in order to weaken the
`electromagnetic attraction between the coils to circumvent
`this problem,there is the problem that power supplied to the
`storage battery of the radiotelephone also decreases, causing
`charging efficiency to drop, and making rapid charging
`impossible.
`
`SUMMARYOF THE INVENTION
`
`invention is to provide a
`The object of the present
`noncontacting charging device which has high charging
`efficiency and which morcover allows easy removal of the
`radio communication device from the charger, should it be
`needed for use such as to make or receive a call during
`charging.
`In addition, another object of the present invention is to
`provide a noncontacting charging device that allows easy
`connection or disconnection between the radiotelephone and
`charger.
`
`20
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`2
`To achieve the above-described objects, the noncontact-
`ing charging device of the present invention is a charging
`device for supplying,
`in a noncontacting state, electrical
`power to a storage battery of a battery-equipped radio
`conununication device, comprising a charger having a pri-
`mary coil and alternating current supply means for supply-
`ing alternating current powerto the primary coil; a second-
`ary coil that couples electromagnetically with the primary
`coil, and charging-power supply means for supplying, as
`charging power, electrical power of the induced current
`produced in the secondary coil to the storage battery; halt
`signal generating means for generating a halt signal that
`commandsa halt of the supply of alternating current power
`to the primary coil; and halting meansforhalting the supply
`of alternating current power to the primary coil in response
`to a halt signal; the secondary coil, charge power supply
`means, and halt signal generating means being provided in
`the radio communication device.
`By meansof this device, a halt signal is issued from the
`radio communication device. By meansofthis signal, charg-
`ing may be halted through the operation effected on theside
`of the radio communication device when it is necessary to
`make or receive a call while charging the radio communi-
`cation device, thereby eliminating the effect of electromag-
`netic attraction upon the radio communication device and
`enabling easy removal of the radio communication device
`from the charger. Consequently, the process of removing a
`radio communication device from a charger is made easy.
`According to a preferable form of the halting means the
`radio communication device is provided with a first phoio-
`electric converting means that converts the halt signal to a
`light signal and outputs it to the charger; and the chargeris
`provided with photoelectric a second converting means that
`receives the light signal and converts it to an electrical
`signal, and cut-off circuit means for cutting the path of
`powersupply to the primary coil in response to the output of
`the a second photoelectric converting means.
`Through this simple construction, the halt signal can be
`transmitted from the radio communication device side to the
`charger side without direct contact by means of a light
`signal.
`The halt signal generating means can be made up ofat
`least one console key for commanding a halt of the supply
`of alternating current power to the primary coil, anda first
`halt signal generating circuit for producing a halt signal in
`response to a signal generated by key input to this console
`key.
`Further, the halt signal generating means may also include
`a second halt signal generating circuit for detecting an
`incoming call to the radio communication device and out-
`putting a halt signal.
`By meansofthis halt signal generating means, whena call
`must be originated or received during charging of the radio
`communication device, charging can be halted cither
`through the operator’s manipulation of the console key of
`the radio communication device or automatically when an
`incoming call is detected, and in this way the radio com-
`munication device may be lightly removed from the charger,
`thereby allowing easy use of the radio communication
`device.
`
`As halting means, a switch for cutting the power supply
`path to the primary coil by manual operation may be
`provided in the charger. Charging may halted by manual
`operation of this switch.
`The above and other objects, features, and advantages of
`the present invention will become apparent from the fol-
`
`4
`
`

`

`5,600,225
`
`3
`lowing description referring to the accompanying drawings
`which illustrate an example of a preferred embodiment of
`the present invention.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG.1 is an exterior view showing the construction of one
`embodiment of a charging device of the present invention;
`and
`
`FIG. 2 is a block diagram showing the internal construc-
`tion of the charging device shownin FIG. 1.
`
`DETAILED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`
`The invention will next be explained with referenceto the
`accompanyingfigures.
`FIG. 1 is an exterior perspective view showing one
`embodiment in which the noncontacting charging device of
`the present invention is applied to a radiotelephone. FIG. 2
`is a block diagram illustrating the circuit construction of the
`device shownin FIG. 1. The charger 1 for supplying power
`for charging to the radiotelephoneis installed within a base
`case 101. A depression 102 into which the radiotelephone
`may be inserted is provided on the upper surface of the base
`case 101, and a primary coil 103 is providedin the base case
`101 for producing magnetic flux which runs aroundthe side
`walls of the depression 102 in a vertical plane. This primary
`coil 103 is connected to an oscillating circuit 104 for
`supplying alternating current to the coil. In addition, an
`oscillating circuit contro] section 105 is provided for sup-
`plying electrical power to this oscillating circuit 104. A
`manually operated switch 106 for turning on and off the
`power supplied to the oscillating circuit 104 is connected to
`the oscillating circuit control section 105. This switch 106 is
`provided in a portion of the upper surface of the base case
`101.
`
`the charger 1 is provided with a light-
`Furthermore,
`receiving element circuit 107. The light-receiving element
`circuit 107 is arranged facing a transparent window 108
`providedin a portion of the depression 102, and in response
`to a light signal transmitted through the transparent window
`108, outputs a signal for on/off controlling a power switch
`circuit (not shown) incorporated in the oscillating circuit
`control section 105. In the present embodiment, a photo-
`diode is used as the light-receiving element circuit, and a
`powercord 109 for supplying power from an external power
`source not shown to the oscillating circuit control section
`105 is led out from the base case 101.
`
`Theradiotelephone 2 is provided with a microphone 202,
`a console keyboard 203, a display 204, a receiver 205, and
`an antenna 206 mounted on a slender telephone case 201.
`Inside the telephone case 201 are provided a knowntele-
`phone speech network made up of a transmitter-receiver
`(TRX) 207, a baseband circuit section 208, a control section
`209, and a keyboard control circuit 214, and as a power
`source, a storage battery 210. This storage battery 210 is
`connected to a secondary coil 212 by way of an AC-DC
`conversion circuit 211. In addition, a light-emitting element
`circuit 213 is connected to the control section 209. In the
`present embodiment, this light-emitting elementcircuit 213
`is made up ofa light-emitting diode. The console keyboard
`203 and control section 209 are connected by way of
`keyboard control section 214.
`The baseof the telephone case 201is constructed to allow
`insertion into the depression 102 provided in the base case
`101, and in this way the radiotelephone 2 may be placed on
`
`10
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`4
`the charger 1 in an erect state. The secondary coil 212 is
`provided within the base portion of the case 201 of the
`radiotelephone 2, and a transparent window 215is provided
`in the bottom surface and the light-emitting element circuit
`213 is provided facing the window 215. Transparent win-
`dows 215 and 108 are arranged in face-to-face positions.
`To operate,
`the radiotelephone 2 is placed upon the
`charger 1 when the storage battery 210 built
`into the
`tadiotelephone 2 is to be charged. At this time, the radio-
`telephone 2 is held in an erect state by meansofinsertion of
`the base portion of the telephone case 201 ofthe radiotele-
`phone 2 into the depression 102 provided in the base case
`101 of the charger 1. The charger 1 is then connected by way
`of power cord 109 to an external power source not shown,
`and switch 106 is turned on. This causes, in the charger 1,
`the power controlled by oscillating circuit contro] section
`105 to be supplied to the oscillating circuit 104. An alter-
`nating current signal of prescribed frequency generated in
`this oscillating circuit 104 is supplied to the primary coil
`103. Asa result, an alternating magnetic field is generated by
`the primary coil 103 within the depression 102 in the base
`case 101 of the charger 1.
`This alternating magnetic field generates an inducedelec-
`tromotive force in the secondary coil 212 arranged in the
`base portion of the telephone case 201 of the radiotelephone
`2. The alternating current arising from this inducedelectro-
`motive force is converted to direct current in an AC-DC
`conversion circuit 211. The direct current power outputted
`from the AC-DC conversion circuit 211 is supplied to the
`storage battery 210 and causes the battery to be charged. In
`this way, the storage battery 210 built into the radiotele-
`phone 2 can be charged without beingelectrically connected
`to the charger 1, i.e., while in an electrically noncontacting
`state.
`
`Whencharging is completed, or when it is necessary to
`take up the radiotelephone 2 from the charger for a call
`during charging, electromagnetic attraction caused by the
`electromagnetic induction between the primary coil 103 and
`the secondary coil 212 will be in effect if nothing is dealt
`with the charger, and will cause considerable force to be
`required to overcomethis electromagneticattraction in order
`to lift the radiotelephone 2 from the charger 1. In this case,
`switch 106 is operated, and by meansof oscillating circuit
`control section 105, the supply of powerto oscillating circuit
`104 is halted, and the oscillation in oscillating circuit 104
`stops. By holding back the generation of magnetic flux in the
`primary coil 103, the electromagneticattraction between the
`two coils can be checked and the radiotelephone 2 can be
`lifted with a normal amount of force.
`
`A first halt-signal generating circuit is provided in the
`control section 209 for supplying a halt signal in response to
`a signal generated by pushing specified keys of the console
`keyboard 203 on the radiotelephone2 thatis to be lifted. The
`halt signal delivered from the control section 209 is con-
`verted to a light signal by the light-emitting element circuit
`213 and supplied from window 215in the base portion of the
`telephonecase 201. This light signal passes through window
`108 provided in the base case 101 of the charger 1,
`is
`received by the light-receiving element circuit 107 and
`converted to an electrical signal. This electrical signal is
`transmitted to the oscillating circuit control section 105 and
`causes the oscillation of the oscillating circuit 104 to stop.
`Accordingly, if the user sets the key at the most accessible
`position when holding the radiotelephone as the specified
`key mentioned above,this key can be easily operated to halt
`oscillation in the oscillating circuit 104 when picking up the
`radiotelephone with one hand and enable easy lifting of the
`radiotelephone 2.
`
`5
`
`

`

`5,600,225
`
`6
`5
`the disclosure is
`set forth in the foregoing description,
`It is also possible to provide a second halt signal gener-
`ating circuit in the control section 209 of the radiotelephone
`illustrative only, and changes may be madein the arrange-
`2 for detecting an incomingcall and producinga halt signal.
`ment of the parts within the scope of the appended claims.
`Whatis claimed is:
`In such a case, a halt signal is produced automatically upon
`1. A noncontacting charging device for supplying, in a
`arrival of an incoming call. As in the case of the previously
`described halt signal, this halt signal is converted to a light
`noncontacting state, electrical power to a storage battery of
`signal in the light-emitting element circuit 213. The charger
`a battery-equipped radio communication device, compris-
`1 receives the light signal at the light-receiving element
`ing:
`circuit 107 which converts the light signal into an electrical
`a charger having a primary coil and alternating current
`signal. This electrical signal causes the oscillating circuit
`supply means for supplying alternating current power
`control section 105 to halt oscillation in the oscillating
`to said primary coil;
`circuit 104. Accordingly, charging can be halted automati-
`a secondary coil that couples electromagnetically with
`cally when there is an incoming call to the radiotelephone 2
`said primary coil, and charging-power supply means
`even during charging, and a user is enabledto easily lift the
`for supplying, as charging power,electrical powerof an
`radiotelephone 2.
`induced current produced in said secondary coil to said
`the previously
`Although not shown in the figures,
`storage battery;
`described switch 106 may be constructed as a contact switch
`arranged on the inner bottom or inner side surface of the
`halt signal generating means for generating a halt signal
`depression 102 such that the switch is turned on when the
`in response to one of an incoming call and a manual
`radiotelephone is placed within the charger. In this case, a
`input that commandsa halt of the supply of alternating
`20
`construction is possible by whichaslight tilting of the
`current power to said primary coil; and
`radiotelephone 2 within the depression 102 causes the
`halting meansfor halting the supply ofalternating current
`contact switch to turn off, thereby halting oscillation of the
`power to said primary coil in response to said halt
`oscillating circuit 104 and halting charging so that the
`signal;
`radiotelephone can belifted with a minimum of effort.
`said secondary coil, said charging power supply means,
`While the embodiment described hereinabove presents
`and said halt signal generating means being provided in
`one example in which the present invention is applied to a
`said radio communication device.
`chargeable radiotelephone,
`the ideal application of the
`2. A noncontacting charging device according to claim 1
`present invention is in applications of the apparatus of the
`wherein said halting means comprises:
`present invention to any radio communication device which
`has a built-in chargeable battery and which may be needed
`a first photoelectric converting means provided in said
`for immediate use even during charging, for example, radio
`radio communication device for converting said halt
`paging devices or radio communication devices such as
`signal to a light signal and supplying said light signal
`transceivers.
`to said charger; and
`a second photoelectric converting means for receiving
`said light signal and converting said light signal to an
`electrical signal, and cut-off circuit means for cutting
`the path of power supply to said primary coil
`in
`response to output of said second photoelectric con-
`verting means, said second photoelectric converting
`means and said cut-off circuit means being provided in
`said charger.
`3. A noncontacting charging device according to claim 1
`wherein said halting means comprises a manually operated
`switch provided in the charger for cutting the power supply
`path to the primary coil.
`4. A noncontacting charging device for supplying, in a
`noncontacting state, electrical power toa storage battery of
`a battery-equipped radio communication device, compris-
`ing:
`a charger having a primary coil and alternating current
`supply means for supplying alternating current power
`to said primary coil;
`a secondary coil that couples electromagnetically with
`said primary coil, and charging-power supply means
`for supplying, as charging power, electrical power of an
`induced current producedin said secondary coilto said
`storage battery;
`halt signal generating means for generating a halt signal
`that commands a halt of the supply of alternating
`current powerto said primary coil; and
`halting meansfor halting the supply of alternating current
`power to said primary coil in response to said halt
`signal; wherein said halt signal generating means com-
`prisesat least one console key for commandingthe halt
`of the supply of alternating current power to said
`primary coil, and a first halt signal generating circuit for
`
`By automatically generating a halt signal when the con-
`sole keyboard of the radio communication device is manipu-
`lated or when there is an incoming call to the radio com-
`munication device,
`it
`is possible
`to halt
`charging
`automatically or through an easy operation when a call must
`be made or received during charging of the radio commu-
`nication device, thereby further facilitating handling of the
`radio communication device upon call sending or call
`receiving.
`By converting the halt signal to a light signal and sup-
`plying it to the charger, it is possible 10 transmit the halt
`signal from the radio communication device to the charger
`without direct contact.
`
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`
`The present invention may be summarized as follows:
`By providing halting means for halting the supply of
`power to a primary coil provided in a charger of a noncon-
`tacting charging device, and by activating this halting means
`whenthe radio communication deviceis to be removed from
`the charger for use, electromagnetic attraction between the
`primary coil in the charger and the secondary coil within the
`radio communication device arising during charging of the
`radio communication device can be eliminated,
`thereby
`allowing lifting of the radio communication device with
`minimal effort and easing the handling of the radio com-
`munication device.
`
`The halting means for halting power supply to the primary
`coil may be constructed as a manually operated switch
`provided in the charger that cuts the power supply path to the
`primary coil, and merely operating this switch allows the
`radio communication device to be lifted with a minimum of
`effort.
`
`It is to be understood, however, that although the char-
`acteristics and advantagesofthe present invention have been
`
`6
`
`

`

`5,600,225
`
`7
`in response to a signal
`producing said halt signal
`generated by a key input to said console key;
`said secondary coil, said charging power supply means,
`and said halt signal gencrating means being provided in
`said radio communication device.
`5. A noncontacting charging device according to claim 4
`wherein said halting means comprises:
`a first photoelectric converting means provided in said
`radio communication device for converting said halt
`signal to a light signal and supplying said light signal
`to said charger; and
`a second photoelectric converting means for receiving
`said light signal and converting said light signal to an
`electrical signal, and cut-off circuit means for cutting
`the path of power supply to said primary coil
`in
`response to output of said second photoelectric con-
`verting means, said second photoelectric converting
`meansand said cut-off circuit means being provided in
`said charger.
`6. A noncontacting charging device for supplying, in a
`noncontacting statc, clectrical powcr to a storage battery of
`a battery-equipped radio communication device, compris-
`ing:
`a charger having a primary coil and alternating current
`supply means for supplying alternating current power
`to said primary coil;
`a secondary coil that couples electromagnetically with
`said primary coil, and charging-power supply means
`for supplying, as charging power,clectrical powerof an
`
`10
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`8
`induced current producedin said secondary coil to said
`storage battery;
`halt signal generating means for generating a halt signal
`that commands a halt of the supply of alternating
`current powerto said primary coil; and
`halting means for halting the supply of alternating current
`power to said primary coil in response to said halt
`signal; wherein said halt signal generating means com-
`prises a secondhalt signal generating circuit for detect-
`ing an incomingcall to the radio communication device
`and producing said halt signal;
`said secondary coil, said charging power supply means,
`and said halt signal generating means being provided in
`said radio communication device.
`7. A noncontacting charging device according to claim 6
`wherein said halting means comprises:
`a first photoelectric converting means provided in said
`radio communication device for converting said halt
`signal to a light signal and supplying said light signal
`to said charger; and
`a second photoelectric converting means for receiving
`said light signal and converting said light signal to an
`electrical signal, and cut-off circuit means for cutting
`the path of power supply to said primary coil
`in
`response to output of said second photoelectric con-
`verting means, said second photoelectric converting
`means and said cut-off circuit means being provided in
`said charger.
`
`7
`
`

`

`>February 4, 1997
`DATED
`INVENTOR(S) : Masataka Goto
`
`It is certified that error appears in the above-indentified patent and that said Letters Patent is hereby
`corrected as shown below:
`
`Column 2,
`
`line 34:
`
`"photoelectric a second"
`
`should read --a second photoelectric-——
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`
`Cammissioner of Parents and Trademarks
`
`Signed and Sealed this
`
`FourthDayof August, 1998
`
`Wace hme
`
`BRUCE LEHMAN
`
`Allest:
`
`Attesting Officer
`
`8
`
`

`

`
`
` UNITED STATES PATENT AND TRADEMARK OFFICE
`
`CERTIFICATE OF CORRECTION
`
`
`PATENT NO.
`:
`54600, 225
`
`
`DATED
`:
`February 4, 1997
`
`INVENTOR{S): Masataka Goto
`
`
` it is certified that error appears in the above-indentified patent and that said Letters Patentis hereby
`
`corrected as shown below:
`
` On the Title Pager, after Section [76],
`insert
`
`the following:
`--
`[73] Assignee:
`NEC Corporation
`
`
` Tokyo, Japan-- Signed and Sealed this
`
`BRUCE LEHMAN
`
`
`
`Third Day of November, 1998
`
`altelWSnce hin
`
`
`
`
`Attesting Officer
`
`Commissioner of Patents and Trademarks
`
`9
`
`