Patent ID: 8420998

Claim:
A target detecting method for detecting a target by emitting a laser beam diagonally downward from an installing position of a laser emitting and receiving portion, the method comprising: obtaining height information of the object to be processed, based on distance information from the laser emitting and receiving portion to the object to be detected; determining, when the object to be detected approaches the laser emitting and receiving portion, that tracking of the object to be detected has stopped when no laser beam reflected from the object to be detected is received; and determining, upon the determination that the tracking of the object to be detected has stopped, whether the object to be detected is the target or a non-target based on height information obtained immediately before the tracking of the object to be detected has stopped, the target determining step, if the height information obtained immediately before the tracking of the object to be detected has stopped shows a predetermined length or above, determining that the object to be detected is the target, the target determining step, if the height information obtained immediately before the tracking of the object to be detected has stopped shows less that the predetermined length, determining that the object to be detected is the non-target.