| 摘要 |
PROBLEM TO BE SOLVED: To prevent generation of dirtiness on a light projection reception surface of optical fiber so as to maintain a highly accurate detection of termination point in a polishing device with an optical polishing termination detector by additionally providing a washer to clean the surface. SOLUTION: An optical fiber 20 set so that a projection reception surface 20a at its tip may face the inside of a recess 25 on a surface of a surface plate 10 is covered with a non-transmitting tube for liquid 28 in which a flow passage 29 opened at the recess 25 is formed in the tube 28. At a tip of the passage 29 a porous member of liquid transmitting type 32 is mounted. During polishing work, washing liquid is supplied into the recess through the member 32 as well as the flow passage 29. Thereby the projection reception surface 10a is cleaned to prevent adhesion of dirt thereto. |
