| 摘要 |
<p>PURPOSE:To facilitate the entering/leaving management of a person at a construction job site of a specific building by closing up tightly an ID element being a transponder which contains no battery by hermetic sealing and attaching it to a cap. CONSTITUTION:To the left and the right of a cap 3, ID elements 4, 5 are attached. By adopting a transponder of a radio frequency for these two elements, the entering direction of a person can be detected by a difference of distances d1, d2 to an antenna 6 of a receiver. In this case, by changing the frequency of two elements, or using a different cord, or interposing a radio wave obstacle between the elements, its detection performance can be improved.</p> |
