| 摘要 |
PROBLEM TO BE SOLVED: To record/reproduce optical disks having information recording surfaces 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 a returning light reflected by an information recording surface toward the light emitting element. SOLUTION: A laser luminous flux 11 emitted from a laser diode 1 is reflected by a polarizing beam splitter 2, made a roughly parallel luminous flux by a collimator lens 3, made incident on an objective lens 4 and converged on the information recording surface 7' of a high density optical disk 7. A luminous flux emitted from a laser diode 1' is intercepted in its peripheral part by a luminous flux intercepting part 5b, made a luminous flux to pass through a circular opening 5a, transmitted through the polarizing beam splitter 2, similarly made incident on the objective lens 4 and then converged on the information recording surface of a conventional optical disk. On the other hand, a returning light from the optical disk 7 is reflected toward a photodiode 6 by a half mirror prism 15. |
