| 摘要 |
<P>PROBLEM TO BE SOLVED: To stably give an alarm by transmitting a trigger wave from an alarm controller mounted on a fork lift and receiving it by an RFID tag carried by an operator. <P>SOLUTION: The trigger wave α emitted from an RFID reader of the fork lift is composed of an electromagnetic wave of long-wave band. A transmission antenna 22 attached to an upper portion of a head guard 16 in a horizontal attitude is composed of a magnetic field loop antenna, which has a loop-like shape having a circumferential length of 3.0 m or more and 10.0 m or less, and includes a multiply-wound loop body 22a having a total length of a multiply-wound antenna wire within the range of 0.005-0.015 times the wavelength of transmitter pulse, and a resin-made cover 51 housing the loop body 22a. <P>COPYRIGHT: (C)2013,JPO&INPIT |
