| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayer optical recording pickup capable of easily adjusting the converging position and the slit position of a reproducing signal on the optical axis and also capable of detecting the reproducing signal even if the optical axis is displaced owing to wavelength fluctuations of a laser beam source. SOLUTION: A component extracted by a slit 7 is detected as a signal light by a photodetector 8 and a confocal detection is realized by using the slit 7 which has two times width of the Airy disk diameter d of a reproducing signal optical system and which is arranged making the longitudinal direction correspond to the radial direction of the multilayer optical recording medium in place of a pinhole which converges return light of laser beams condensed on either one recording layer of the multilayer optical recording medium 5 having plural layers of recording layers 5a, 5b and 5c in the thickness direction of the medium and which extracts the component corresponding to the above one recording layer from return light. |
