Communications: electrical – Selective – Interrogation response
Reexamination Certificate
1998-06-19
2001-02-27
Zimmerman, Brian (Department: 2735)
Communications: electrical
Selective
Interrogation response
C340S870030, C235S435000, C235S439000, C235S492000, C343S702000, C343S895000
Reexamination Certificate
active
06194993
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a reader and/or writer apparatus, a power feeding system and a communication system for performing power feeding for proximate wireless operation and communication between, for instance, a cash dispenser, electronic money, an automatic ticket checking system, a room entrance/exit management system or a pay telephone and a proximate wireless card, such as a cash card, a credit card, a passenger ticket, a commuting ticket, a coupon ticket, a control card, an IC card, a license or a telephone calling card.
It is already known that, by using light or a magnetic field, electric power can be supplied in a non-contact manner from the power feeding side to a proximate wireless card (IC card).
For example, Japanese Patent No. 2626882 (JP-A-8-263609) discloses a technique related to disposing a metal plate on a back of a coil-shaped antenna to prevent wrong operation such as reading card data from a back of a non-contact card reader, especially a technique for adjusting a distance between the metal plate and the coil-shaped antenna in consideration of the fact that the resonant frequency shifts when the metal plate is disposed.
In non-contact card systems (proximate wireless card systems), cash cards, credit cards, passenger tickets, commuting tickets and the like for use at the gates of railway stations, on buses and exit/entrances are made as IC cards. When the user of such an IC card causes the IC card to pass in a non-contact manner through a reader/writer provided at the gate of a railway station, on a bus or at an exit/entrance, a power feeding wave or a communication wave is radiated from a coil or an antenna of the reader and/or writer, this electromagnetic wave is received and induced by a coil or an antenna on the card side to actuate a circuit on the card side and to detect a signal. In this case, an electric field radiated from the coil or antenna of the reader and/or writer should satisfy the requirement of the Wireless Telegraphy Act (500 &mgr;V/m at a distance of 3 m from the reader and/or writer).
However, there is involved the problem that, as the aforementioned requirement of the Wireless Telegraphy Act (500 &mgr;V/m at a distance of 3 m from the reader and/or writer) regarding the radiated electric field determines the upper limit of the amperage of the coil or antenna for the reader and/or writer and hence the upper limit of power feeding, it is difficult to feed sufficient power to the IC card. That is, there is involved the problem that sufficient power feeding from the reader and/or writer to the IC card at a desired distance from the reader and/or writer and suppression of a far field prescribed in the Wireless Telegraphy Act is difficult.
SUMMARY OF THE INVENTION
In order to solve the aforementioned problems, a first object of the present invention is to provide a reader and/or writer apparatus, a power feeding system and a communication system in a proximate wireless card system arranged so that power which satisfies the requirement of the Wireless Telegraphy Act (500 &mgr;V/m at a distance of 3 m from the reader and/or writer apparatus) regarding the radiated electric field can be supplied sufficiently from the reader and/or writer apparatus to the proximate wireless card (IC card).
A second object of the invention is to provide a reader and/or writer apparatus, a power feeding system and a communication system in a proximate wireless card system which performs high-efficiency power feeding by making acceptable an error in the positioning of the IC card proximate to an antenna provided on the reader and/or writer apparatus.
In order to achieve the first object, according to one aspect of the present invention, a reader and/or writer apparatus has of a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to an IC card, and a conductor member for forming a mirror image of the antenna.
According to another aspect of the present invention, a reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating electromagnetic fields both to supply operational power to an IC card and to transmit and/or receive signals for communication to/from the IC card, and a conductor member for forming a mirror image of the antenna.
The just-mentioned the reader and/or writer apparatus according to the present invention comprises a power supply for generating a signal for power feeding, an encoding circuit for encoding inputted transmit data, a modulator for amplitude-modulating the signal obtained from the power supply with a signal obtained from the encoding circuit so that the signal obtained from encoding circuit is superimposed on the signal obtained from the power supply, and a power feeding circuit for feeding power to an antenna on the basis of a signal obtained from the modulator.
According to still another aspect of the present invention, a reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to an IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
According to yet another aspect of the present invention, a reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating electromagnetic fields both to supply operational power to an IC card and to transmit and/or receive signals for communication to/from the IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
The just-mentioned reader and/or writer apparatus according to the invention comprises a power supply for generating a signal for power feeding, an encoding circuit for encoding inputted transmit data, a modulator for amplitude-modulating the signal obtained from the power supply with a signal obtained from the encoding circuit so that the signal obtained from encoding circuit is superimposed on the signal obtained from the power supply, and a power feeding circuit for feeding power to an antenna and an image antenna on the basis of a signal obtained from the modulator.
According to yet another aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this D.C. voltage to an internal circuit of the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to the IC card and a conductor member for forming a mirror image of the antenna.
According to still another aspect of the present invention, a communication system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card and for performing transmission and/or reception of signals for communication to and/or from the IC card, is provided. wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field both to supply operational power to the IC card and to perform transmission and/or reception of signals for communication to and/or from the IC card and a conductor member for forming a mirror image of the antenna.
According to yet another aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this D.C. voltage to an internal circuit of the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to the IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
According to still another aspect of the present invention, a communication syst
Hayashi Yoshihiko
Igarashi Keisuke
Suga Takashi
Uesaka Kouichi
Yoshino Ryouzou
Antonelli Terry Stout & Kraus LLP
Dalencourt Yves
Hitachi , Ltd.
Zimmerman Brian
LandOfFree
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