| 摘要 |
PURPOSE:To make possible the observation of the entire inside circumferential surface of a fine tube by providing an optical system having a circular conical reflecting surface in front of an image fiber. CONSTITUTION:A 360 deg. side observing mirror 4 of a circular cone shape is provided as a reflecting optical system in front of an image fiber 3. The face image of the inside surface 2 of the tube 1 to be observed is changed of its optical path by the mirror 4, is made incident to the fiber 3 and is sent to an observation position. In this case, light is introduced as a light guide 6 as an irradiation function, and the inside surface 2 is irradiated by the light reflected on the 360 deg. side irradiating part 8 of a 360 deg. side observing mirror 7 and the reflected light thereof is made incident to the fiber 3 through a 360 deg. side observing part 9. |
