JPS6449542A - Measuring endoscope - Google Patents

Abstract

PURPOSE:To easily and accurately recognize a ruggedness occurring in a specimen, by superposing a one-dimensional fiber diffraction grating for diffracting a laser in one direction of either row or column upon another one-dimensional fiber diffraction grating or a lens with a different diffraction angle for diffracting or magnifying the diffracted laser in the other direction. CONSTITUTION:A two-dimensional transmitting diffraction grating 10 is constructed by superposing a first one-dimensional fiber diffraction grating 4 for diffracting a laser in the column direction upon a second one-dimensional fiber diffraction grating 5 with a different diffraction angle for diffracting the diffracted laser in the row direction. When a laser is entered into the transmitting diffraction grating 10, the laser is first diffracted in the column direction by the one-dimensional fiber diffraction grating 4 by, e.g., 0.28 deg. pitch and is then diffracted in the row direction by the one-dimensional fiber diffraction grating 5 by, e.g., 2.75 deg. pitch. A two-dimensional spot-light pattern close to a vertical stripe pattern, wherein the spaces between spots in the column direction are shortened, is projected on the specimen 3. From the above pattern clearly displayed on a monitor, a ruggedness occurring the specimen 3 is easily and accurately recognized.