| 摘要 |
SOLUTION: Provided is a device which, with its tip disposed inside the hole of an inspection object 8, inspects the state of an inner surface 810 of the hole, the device having a rod lens 21, a ring illumination 22 disposed on the base end side of the rod lens 21, a coaxial illumination 23 and image-capturing means 24, and an illumination control unit. The rod lens 21 has, at its tip, a reflection part 212 for reflecting the light incident from the radial direction side toward the base end side. The ring illumination 22 projects ring-shaped light having a prescribed angle to the axial direction into the rod lens 21, and the coaxial illumination 23 projects light almost parallel to the axial direction into the rod lens 21. The illumination control unit is capable of adjusting at least one luminous energy of the ring illumination and the coaxial illumination stepwise in accordance with a luminary energy set value.EFFECT: Since the ratio of luminous energy between the ring illumination and the coaxial illumination can be adjusted, it is possible to detect even a small irregularity, and to perform inner surface inspection on various defects with few false recognition using an illumination having appropriate directivity, making it possible to improve the accuracy of detecting various kinds of defects.SELECTED DRAWING: Figure 2 |
