| 摘要 |
PURPOSE:To facilitate the angle adjustment of a diffraction grating by forming a projection to a cylinder face of a cylindrical holder holding the diffraction grating so as to form an engaged rugged part relatively to the face of the projection orthogonal to the optical axis passing through the diffraction grating and the opposed with a screw driver in press contact with the projected face. CONSTITUTION:The cylindrical holder 3 holding the diffraction grating forms the engaged rugged part with a screw driver on the face orthogonal to the optical axis of the projection from the cylinder face. In adjusting the angle of the diffraction grating 2, a screw drive 9 is inserted to the disc face from the vertical direction and an eccentric pin 11 provided to the tip of the screw driver as the projection is engaged with a slot 13. In turning the screw driver 9, the cylindrical holder 3 is turned around the optical axis by the operation of the eccentric pin 11 to adjust the minute angle of the diffraction grating 2 thereby bringing the sensitivity of the tracking control into the best state.
|
