| 摘要 |
<p>An optical displacement measuring apparatus 10 includes a light source 20, a collimate lens 22, a mirror 24, and a truncated cone shaped prism 30, and includes an imaging lens 40 and a pinhole optical device 50 for extracting light parallel to an optical axis of incident light 72 from light returned from an object 8 through the truncated cone shaped prism 30, and an optical position detector 60. The truncated cone shaped prism 30 has optical properties of converting only light returned to a truncated conical circumference surface at a fixed angle corresponding to an apex angle into light parallel to an optical axis of incident light. The parallel light is offset from an optical axis 80 of incident light 72 in accordance with a displacement of the object 8 relative to the truncated cone shaped prism 30. The optical position detector 60 detects an offset amount to measure the displacement of the object 8.</p> |
