To provide an optical head capable of further improving the recording/reproducing characteristics of an optical recording medium by reducing the difference of a phase changing amount in an optical spot caused by a light incident angle.
This device includes a liquid crystal element 27 disposed on the optical path of a return light between a beam splitter 24 and a photodetector 31 and divided into a plurality of areas, a voltage applying means 28 for applying voltages of the plurality of divided areas of the liquid crystal element 27 to change the refraction indexes of the divided areas, and a control means 29 for controlling the operation of the voltage applying means 28 to adjust a phase compensation amount provided to each divided area with respect to a light made incident on the divided area of the liquid crystal element 27 and a uniform phase change is given to the spot of a light passing through the liquid crystal element 27 in the spot. Thus, the difference of phase changing amounts in the optical spot caused by the incident angles of lights made incident on the liquid crystal element 27 is reduced, and the reproducing characteristics of an optical recording medium 32 are improved.
| JP2000306278A | 2000-11-02 | |||
| JP2003296960A | 2003-10-17 | |||
| JP2006196122A | 2006-07-27 | |||
| JP2000306278A | 2000-11-02 | |||
| JP2003296960A | 2003-10-17 | |||
| JP2006196122A | 2006-07-27 |
Takeshi Sugiyama
Minetarou Hirose
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