| 摘要 |
PROBLEM TO BE SOLVED: To provide a metal ball detection sensor capable of shielding a detection coil, without having to add extra members. SOLUTION: A detection hole 20 passed by a metal ball is provided in a body case 1, and a detection coil 6 is arranged so as to enclose the periphery of the detection hole 20 inside the case, and a detection circuit, including an oscillator for detecting a change generated when the metal ball passes the detection hole by the detection coil 6, is provided. A hole 9, having the diameter corresponding to the detection hole 20, is formed, and a shield part 31 for holding the whole circuit substrate, including the oscillator at a prescribed voltage level, is provided in the periphery of the hole 9. Hereby, this metal ball detection sensor for stabilizing a detection characteristic of the playing ball and having sharpened sensitivity can be realized. COPYRIGHT: (C)2007,JPO&INPIT |
