| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an information pickup device and an optical disk device capable of reproducing optical information recording media having different substrate thickness with one optical pickup, of which structure having compatibility with each other is simple, and which is compact. <P>SOLUTION: In an information pickup device of an optical information recording medium having a laser beam source, a beam splitter, an objective lens having positive refractive power converging luminous flux from the laser beam source passing through the beam splitter on an information recording surface through a transparent substrate of an optical information recording medium, and a light receiving means for receiving the luminous flux reflected by the information recording surface and passing through the objective lens and the beam splitter, the device is provided with a radiation degree changing means changing a radiation degree of the luminous flux made incident on the objective lens in accordance with thickness of the transparent substrate. <P>COPYRIGHT: (C)2009,JPO&INPIT |
