1. Field of the Invention
The present invention relates to a wireless IC tag and an information management system and particularly, to a wireless IC tag including a counter, and an information management system including both of the wireless IC tag and a wireless IC tag reader/writer (reading and writing apparatus). The wireless IC tag may be called as a IC tag, an electronic tag, Radio Frequency Identification (RFID) tag, or Radio Frequency Identification (RFID).
2. Description of the Related Art
Japanese Non-examined Patent Application (JP-A) No. 2001-256459 discloses a wireless IC tag with a memory, and IC tag reader/writer with a communication control unit that counts down from the number of usable times each time memory data is updated.
JP-A No. 2005-235180 discloses a technique of counting the number of update success times between a reader and a tag by the reader and holding the number of update success times in a memory in the reader.
In the technique of JP-A No. 2001-256459, the life of the wireless IC tag which ends due to exhaustion of a power source provided in the wireless IC tag has to be estimated prior to the use of the wireless IC tag. The power source is also consumed by reading of data, transmission of a response wave, and the like, so that it is insufficient to count only the number of update times of the memory.
In the technique of JP-A No. 2005-235180, the cause of the case where the reader does not receive a response from a wireless IC tag cannot be identified. For example, if the cause is that the wireless IC tag does not receive an interrogation wave (an inquiry wave), it cannot be identified by the technique of JP-A No. 2005-235180.