| 摘要 |
PROBLEM TO BE SOLVED: To record/reproduce optical disks having information recording surface positions different in the thickness direction with the same optical pickup by reflecting or passing, on the same optical path, luminous flux from a light emitting element on the optical path, on which the luminous flux passes, and reflecting returning light reflected by the information recording surface toward a light receiving element. SOLUTION: A laser luminous flux 11 emitted from a laser diode 1 is intercepted in its peripheral part around an optical axis by a luminous flux intercepting part 5b, a laser luminous flux 12 passing through a circular opening part 5a is transmitted through a beam splitter 2m, becoming a roughly parallel luminous flux 13 by a collimator lens 3, then made incident on an objective lens 4 and converged on the information recording surface 8' of a conventional optical disk 8. When an opening control limit element 5 is moved to a position for not intercepting the luminous flux 11 emitted from the laser diode 1, the luminous flux 11 is transmitted through the beam splitter 2, made a roughly parallel luminous flux 13 by the collimator lens 3, then made incident on the objective lens 4 and converged on the information recording surface of a high density optical disk. |
