| 摘要 |
PURPOSE:To cancel the inconvenience in cleaning transparent plates which prevent stain of optical parts at both ends of an optical path between the mobile part and the fixing part of a separation type optical head. CONSTITUTION:The transparent plate 13 and the transparent plate holding mechanism 14 are provided on the incidence part of a laser beam in the movable part 1 of the optical head. The transparent plate 41 emitting the laser beam and a holding member for the transparent plate holding mechanism 42 are provided on the place emitting the laser beam to the fixing part 4 of the optical head, as well. By such constitution, the dustproof transparent plates are easily replaced as necessary and surely prevent the inversion of dirt and dust without using cleaning tools which have inevitably the complicated constitution. |
