IC card reader/writer, identification method

摘要

This invention provides a reader/writer (101), ID method and program comprising a response-detection unit of detecting normal responses and collisions from IC cards (410,420,430) in response to a request; and a response-invalidation unit of sending a response-invalidation command (1117), which is a command not to respond to requests in the future, to IC cards (410,420,430) that sent normal responses when the response-detection unit received normal responses from IC cards (410,420,430) even though collisions were detected. <IMAGE>