| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a non-contact data carrier which starts communication when the carrier is out of a power supply range of a communicated radio electric wave and therefore realizes theft prevention. <P>SOLUTION: When the non-contact data carrier detects the outside of the power supply range of the radio electric wave, communication is started by using a built-in battery 142 and an alarm of theft prevention is emitted. To put it concretely, a radio wave signal that a resonance antenna circuit part 110 receives is rectified and made smooth. When obtained DC voltage is lower than a prescribed value, communication, light emission/sound emission are performed by the built-in battery 142. Namely, a data carrier operation is turned on. When voltage is higher, the operation is turned off. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
