| 摘要 |
PURPOSE:To prevent the influences of stray light on a detected face in a cylindrical ferrule that covers optical fiber and holds the end part by forming a non- reflective face that prevents the reflection of light to the end face of detected object side of the mouthpiece. CONSTITUTION:A detecting head 1 consists of a cylindrical mouthpiece 2, optical fiber 3 inserted with the ferrule and held on its end and a protective tube 4. Thenon-reflective face 7 is formed on the end face 10 opposite to the detected face 6 of the ferrule 2 by coating black paint or sticking a material having high light absorption factor. Thus, reflection does not occur even when reflected light 8 of detected face 6 of an object 5 to be detected or disturbance light 11 irradiates on the end face 10of the mouthpiece 2, and accordingly, there is almost no stray light to the detected face 6. Accordingly, the uniform illumination of the illumination area becomes possible, and the accuracy of detection is improved especially in the optical fiber for detection. |
