| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system for tilt adjustment of objective lens capable of much improving the detecting precision of the tilt angle of objective lens. SOLUTION: This optical system for tilt adjustment of objective lens is provided with an objective lens 1 having an annular plane part 3 provided so as to surround the outer periphery of a lens part 2, a detecting light irradiating system projecting a detecting light beam P for detecting the tilt of the object lens 1 and a detected light receiving system 21 for receiving the detected beam P reflected by the objective lens 1. By detecting the light receiving position of the detected beam P reflected from the annular plane part 3, the tilt of the objective lens 1 to a reference plane 6 is detected. In this case, the lens part 2 has an optical property that the detected beam P is totally reflected plural times by a second surface on the farther side from a first surface on which the detected beam P is made incident and transmitted from the side of the first surface. The detected beam P is made to be a parallel light beam having a diameter larger than the diameter of the annular plane part 3 and the optical axis of the detecting light irradiating system has a prescribed tilt angle to the normal N of the reference plane 6. |
