| 摘要 |
PROBLEM TO BE SOLVED: To rapidly and exactly inspect the degree of inclination of an objective lens for an optical pickup. SOLUTION: This instrument has a light source 21, a collimator 23 which exists between this light source 21 and the objective lens for the optical pickup and changes the light emitted from the light source 21 to parallel beams, a convergent lens 33 which converges the parallel beams past this collimator 23 to the objective lens 10 for the optical pickup, a photodetector 35 which receives the light reflected from the objective lens 10 for the optical pickup and past this converging lens 33 and an optical route changing means 30 which is arranged on the optical route between this converging lens 33 and the collimator 23 and branches the progressing course of the light entering from the light source 21 side to the converging lens 33 side and the photodetector 35 side. In such a case, The angle of inclination of the objective lens 10 for the optical pickup is measured by detecting the difference between the position of the light which is emitted from the light source 21 and is made incident directly on the photodetector 35 and the position of the light which is reflected from the objective lens 10 for the optical pickup and is made incident on the photodetector 35. |
