| 摘要 |
PROBLEM TO BE SOLVED: To accurately measure a passage time of a competitor with fewer frequency channels, in a time measurement system for competition configured to measure a passage time of the competitor at a measurement point in a race course, using an RFID tag attached to the competitor.SOLUTION: Antennae not neighbouring with each other are paired. In respective reader/writers connected to the paired antennae, a carrier sense is performed using the same frequency and at the same timing. If the carrier sense succeeds, carrier radio waves indicating this are sequentially transmitted at a different timing from each other via the connected antennae. When carrier radio waves are transmitted from all reader/writers in the same pair, reading of a tag ID from an IC tag 10 is started at the same timing at the frequency.SELECTED DRAWING: Figure 1 |
