| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pick up device which has a function integrated of an n quarter wavelength plate, having a stability to temperature and aberration correcting means for handling a plurality of optical beams with different wavelengths. <P>SOLUTION: The optical pick up device comprises a laser light source 3, a polarized beam splitter 6, an objective lens 7, a liquid crystal optical element 10, and a liquid crystal controlling means 40 for applying control voltages P4 and P5t to the liquid crystal optical element 10. The liquid crystal optical element 10 is formed, by integrating a first liquid crystal cell 11 for correcting aberrations, and a second liquid crystal cell 12 that function as the n quarter-wave plates which handle a plurality of incoming lights of different wavelengths, and is a composite liquid crystal cell, constituted by injecting the same liquid crystal material to the first liquid crystal 11 and the second liquid crystal 12. The liquid crystal control means 40 comprises a temperature compensation circuit 42 for compensating the temperature of the second liquid crystal 12. <P>COPYRIGHT: (C)2008,JPO&INPIT |
