| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability of detecting a foreign object when detecting medals passing through a route.SOLUTION: A transmission type first to a third optical systems formed by a pair of a light emission part 216 and a light reception part 220 are provided. Among these three optical systems, at least two optical systems are used, as effective optical systems effective for detecting detection objects, for detection of medal M, a luminescence forging object, and a liquid crystal panel forging object. At that time, in the effective optical systems, light emission at each light emission part included in the optical systems is executed, and among the three optical systems, in an optical system except the effective optical systems, light emission at the emission part is not executed. And, a combination of the effective optical systems is set at a prescribed timing on the basis of a first set where a first optical system and a second optical system are the effective systems, a second set where the second optical system and a third optical system are the effective systems, and a third set where the first optical system and the third optical system are the effective systems.SELECTED DRAWING: Figure 6 |
