| 摘要 |
PROBLEM TO BE SOLVED: To obtain desired antenna characteristics without using a large housing, in a non-contact detection device that houses an antenna in the housing made of a good conductor.SOLUTION: A road rivet 2 as a non-contact detection device comprises: a box-like housing 20 made of a good conductor and that has an opening; a non-good conductor lid 30 that blocks the opening of the housing; and a circuit board 18 housed in the housing 20. The circuit board 18 detects a tag 8 approaching the road rivet 2 via coil antennas 12 and 14 assembled in the lid 30, and provides a notification of that by making an LED 16 emit light. The coil antennas 12 and 14 are wound around the lid 30 so that coil axes are parallel to an opening surface of the housing and orthogonal to each other, and are set so that a clearance from an inner wall surface of the housing in the coil axis direction becomes larger than that in the coil axis orthogonal direction.SELECTED DRAWING: Figure 1 |
