| 摘要 |
In order to provide an optical pickup apparatus that has a relatively simple configuration and that can carry out recording and/or reproduction of information in a s compatible manner for different optical information storage medium, the optical surface of the first objective lens OBJ1 is formed only by a refracting surface, and hence it is possible to form it at a low cost even if it is made of glass. In addition, said first objective lens OBJ1 can be designed by optimizing it for the first light flux with the wavelength lambda1 and the protective substrate t1 of said first optical disk OD1. On the other hand, while the second objective lens OBJ2 is used commonly for both the first light flux with a wavelength lambda1 and the second light flux with a wavelength lambda2, when the protective substrate t2 of the second optical disk OD2 and the protective substrate t3 of the third optical disk OD3 are the same, there is no need to consider the difference in the thickness of the protective substrate, and hence the design is easy and it is possible to produce at a low cost.
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