IC card reader/writer, identification method and program
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsFutoshi Nakabe, Tadakatsu Masaki, Shinji Kawano, Hideo Oozeki, Hiromi Ebara
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Abstract
This invention provides a reader/writer, ID method and program comprising a response-detection unit of detecting normal responses and collisions from IC cards in response to a request; and a response-invalidation unit of sending a response-invalidation command, which is a command not to respond to requests in the future, to IC cards that sent normal responses when the response-detection unit received normal responses from IC cards even though collisions were detected.
Claims17
A reader/writer for IC cards that communicates with a plurality of IC cards comprising:
- a response-detection unit operable to detect normal responses from the IC cards in response to a request for identifying each card and collisions of the responses;
- and
- a response-invalidation unit operable to send a response-invalidation command, which is a command not to respond to said requests in the future, to the IC cards that sent normal responses when said response-detection unit received normal responses from the IC cards even though collisions were detected.
A reader/writer for IC cards that uses one or more time slots for communicating with a plurality of IC cards, comprising:
- a collision-detection unit operable to detect collisions of responses from IC cards in response to a request for identifying each IC card;
- and
- a slot-number-increase unit operable to increase the number of time slot based only on whether or not there are collisions detected by said collision-detection unit.
A reader/writer for IC cards that communicates with a plurality of IC cards using one or more time slots, comprising:
- a memory unit operable to store the number of IC cards properly confirmed;
- a calculation unit operable to calculate the number of time slots to be included in the first request for identifying each IC card based on the number of IC cards stored in said memory unit;
- and
- a slot-number-reset unit operable to set the number of time slots calculated by said calculation unit as the number of time slots for said first request.
An ID method of identifying a plurality of IC cards capable of communication, comprising:
- a detection step of detecting normal responses from said IC cards in response to a request for identifying each IC card and collisions of the responses;
- and
- a response-invalidation step of sending a response-invalidation command, which is a command not to respond to said requests in the future, to IC cards that sent normal responses when normal responses were received from IC cards even though collisions were detected.
An ID method of identifying a plurality of IC cards capable of communication, comprising:
- a collision-detection step of detecting collisions of responses from said IC cards in response to a request for identifying each IC card;
- and
- a slot-number-increase step of increasing the number of said time slots used for said identification based only on whether or not said collisions were detected.
An ID method of identifying a plurality of IC cards capable of communication, comprising:
- a memory step of storing the number of IC cards properly confirmed from among a plurality of said IC cards;
- a calculation step of calculating the number of time slots to be included in the first request for identifying each IC card based on the number of IC cards stored in said memory step;
- and
- a slot-number-reset step of setting the number of time slots calculated by said calculation step as the number of time slots for said first request.
A program that can be executed by a computer for identifying a plurality of IC cards capable of communication, comprising:
- a detection step of detecting normal responses from said IC cards in response to a request for identifying each IC card and collisions of the responses;
- and
- a response-invalidation step of sending a response-invalidation command, which is a command not to respond to said requests in the future, to IC cards that sent normal responses when normal responses were received from IC cards even though collisions were detected.
A program that can be executed by a computer for identifying a plurality of IC cards capable of communication, comprising:
- a collision-detection step of detecting collisions of responses from said IC cards in response to a request for identifying each IC card;
- and
- a slot-number-increase step of increasing the number of said time slots used for said identification based only on whether or not said collisions were detected.
A program that can be executed by a computer for identifying a plurality of IC cards capable of communication, comprising:
- a memory step of storing the number of IC cards properly confirmed from among a plurality of said IC cards;
- a calculation step of calculating the number of time slots to be included in the first request for identifying each IC card based on the number of IC cards stored in said memory step;
- and
- a slot-number-reset step of setting the number of time slots calculated by said calculation step as the number of time slots for said first request.
Dependencies are inferred from the claim text.