| 摘要 |
PURPOSE:To surely detect contact of a measuring probe by an apparatus wherein an in-contact signal attendant on displacement of the measuring probe is detected based on the changes in a light signal between a fixed probe and an exchange probe. CONSTITUTION:A light emitted from a light source 24 of a fixed probe 12 hits on a reflection plate 30 through an optical fiber 28, a gap 36 and a projector head 32. When a measuring probe 16 is in a neutral position, the reflected light enters into a photo converter 26 through a photo receiving head 34, gap 36 and an optical fiber 28. Thus, by detecting an output of the photo converter, it is determined that the measuring probe 16 is now in a neutral position. On the other hand, when the measuring probe 16 contacts with an object to be measured 14, the reflection plate 30 is displaced and the reflection light will not enter into the photo receiving head so that the photo converter 26 issues no output. As a result, contact between the measuring probe 16 and the object to be measured 14 can be detected surely. |
