| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head device that has no deterioration or variation in the reproducing signal strength of an optical disk and that is free from change in the writing light quantity on the optical disk. <P>SOLUTION: The optical head device is structured by installing, between an objective lens 6 and a beam splitter 2, a liquid crystal element 4 for varying the wavefront of incident light and a diaphragm 40 for limiting the diameter of the incident light for the purpose of making the diameter smaller than the outer circumference of the electrode area which is formed on a transparent substrate constituting the liquid crystal element 4. <P>COPYRIGHT: (C)2003,JPO |
