Abstract: A liquid crystal optical element having a crystal liquid optical element adapted to positively function as a diffraction element and an optical pickup apparatus including the liquid crystal optical element are disclosed. A transparent electrode having a diffraction pattern is arranged on one of a pair of transparent substrates. A liquid crystal panel has a transparent opposed electrode arranged on the other one of the pair of the transparent substrates. A driving unit generates a phase difference distribution in the liquid crystal layer by generating a potential difference between the transparent electrode and the transparent opposed electrode and causes the liquid crystal panel to function as a diffraction element for diffracting the incoming light beam transmitted therethrough. The diffraction pattern or the transparent opposed electrode is divided into a plurality of regions. The driving unit adjusts the potential difference for each of the regions.

Abstract: The present invention is directed to the provision of an optical pickup apparatus in which a liquid crystal optical element constructed by combining an aberration correcting liquid crystal panel and a ?/4 liquid crystal panel in an integral fashion is mounted in a tilted position. More particularly, the invention provides a liquid crystal optical element comprising a first liquid crystal layer for correcting aberration, a second liquid crystal layer functioning as an n?/4 plate and combined in an integral fashion with the first liquid crystal layer, a transparent electrode for generating a potential difference on the second liquid crystal layer in order to control an amount of phase difference for the light beam passing through the second liquid crystal layer, and a driver for driving the transparent electrode so as to generate a potential difference that is the lowest among a plurality of potential differences that cause the second liquid crystal layer to function as an n?/4 plate.

Abstract: A liquid crystal optical element having a crystal liquid optical element adapted to positively function as a diffraction element and an optical pickup apparatus including the liquid crystal optical element are disclosed. A transparent electrode having a diffraction pattern is arranged on one of a pair of transparent substrates. A liquid crystal panel has a transparent opposed electrode arranged on the other one of the pair of the transparent substrates. A driving unit generates a phase difference distribution in the liquid crystal layer by generating a potential difference between the transparent electrode and the transparent opposed electrode and causes the liquid crystal panel to function as a diffraction element for diffracting the incoming light beam transmitted therethrough. The diffraction pattern or the transparent opposed electrode is divided into a plurality of regions. The driving unit adjusts the potential difference for each of the regions.

Abstract: The present invention is directed to the provision of an optical pickup apparatus in which a liquid crystal optical element constructed by combining an aberration correcting liquid crystal panel and a ?/4 liquid crystal panel in an integral fashion is mounted in a tilted position. More particularly, the invention provides a liquid crystal optical element comprising a first liquid crystal layer for correcting aberration, a second liquid crystal layer functioning as an n?/4 plate and combined in an integral fashion with the first liquid crystal layer, a transparent electrode for generating a potential difference on the second liquid crystal layer in order to control an amount of phase difference for the light beam passing through the second liquid crystal layer, and a driver for driving the transparent electrode so as to generate a potential difference that is the lowest among a plurality of potential differences that cause the second liquid crystal layer to function as an n?/4 plate.