| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a radio tag reader and an RFID system allowing response by a radio tag even if communication quality is deteriorated by a peripheral environment. <P>SOLUTION: This radio tag reader transmits an ASK modulation signal and receives a response signal from the radio tag. The radio tag reader is constructed of a modulation means performing ASK modulation of a carrier wave based on a base band signal and generating an ASK modulation signal, a demodulation means demodulating the receipt signal and generating a demodulation signal, a response signal detection part 29b determining receipt of a response signal from the radio tag based on the demodulation signal, a transmission control part 29a generating a response request based on a trigger signal and repeatedly transmitting the response request until the response signal corresponding to the response request transmitted as the ASK modulation signal is received, and a modulation control part 29c switching a modulation degree of the ASK modulation signal based on a determination result by the response signal detection part 29b. <P>COPYRIGHT: (C)2007,JPO&INPIT |
