| 摘要 |
PURPOSE:To reliably detect breakage of a drill, by a method wherein, by the use of a self-focusing micro lens, an acute light point is formed to the tip part of a drill, and the presence of the tip part of a drill is monitored. CONSTITUTION:Light beam emitted from a projection head 6 is collected by the use of a detector 4 employing a self-focusing micro lens 7, and an acute point of light is formed to the tip part of a drill 1. Meanwhile, a second self-focusing micro lens 9 is disposed to the front of a collecting head 8, a radiation light beam from the self-focusing micro lens 7 is collected to input it to the head 8. Breakage of the tip of the drill 1 is monitored through collection by the head 8. |
