Abstract: A bore hole scanner includes a light projecting device for projecting a light beam toward a bore hole wall surface. A conical mirror is arranged coaxially with respect to a sonde for condensing light reflected from the bore hole wall surface. An image forming device is arranged in front of the conical mirror. A photoelectric transducing device converts a light signal into an electric signal. Optical fibers introduce an image, which is formed on concentric circles by the image forming device to the photoelectric transducing device. A data processing device scans and extracts signals from the photoelectric transducing device and generates and processes image data indicative of the bore hole wall surface. A sonde position detecting device detects the orientation and position of the sonde. Rotating portions are dispensed with by using the conical mirror and optical fibers, and a linear CCD array can be used as the photoelectric transducing device.

Abstract: An optical head (12) is rotated while a sonde (11) is moved up or down within a bore hole (22), and a beam of light from a light source (22) is projected toward the wall of the bore hole (22) via a lens (21), slit (22), half-mirror (19), mirror (15) and lens (14). Light reflected from the bore hole wall is extracted from the half-mirror (19) via a slit (17) and a photoelectric transducer (18) so that the bore hole wall may be continuously observed. By separating the reflected light into spectral components and processing them, color tone logging and other observations can be performed. The orientation of the sonde (11) is sensed by an azimuth finder (23) and rotation gauge (24), and the inclination of the sonde (11) is sensed by a dipmeter (25). Displacement of the sonde accompanying each unit length of up-or-down movement of the sonde (11) is calculated and the displacements are integrated to obtain the position being observed by the sonde.