Optical pickup of tilt control type

An optical pick-up composed of an objective lens and a liquid crystal element in combination, for recording and reproduction of optical discs having different recording densities, the liquid crystal element having seven zones in total, including:

• zones 2, 4 located in center parts of half circles of a small diameter beam for a low density optical disc,
• zones 3, 5 laid along the outer peripheries of the zones 2, 4 within the half circles, respectively, so as to surround the zones 2, 4, respectively,
• zones 6, 7 along the outer peripheries of the zones 3, 5, between the outer periphery of the small diameter beam and a large diameter beam, extending along substantially half circumferential parts of the small diameter beam, respectively,
• a zone 1 which is a remaining zone other than the zones 2, 3, 4, 5, 6, 7 and including a diameter, wherein the direction of the diameter included in the first zone 1 is at right angles to a tilt direction to be corrected.

An optical pick-up composed of an objective lens and a liquid crystal element in combination, for recording and reproduction of optical discs having different recording densities,

• the liquid crystal element having nine zones in total, including:
• zones 2, 4 located in center parts of half circles of a small diameter beam for a low density optical disc,
• zones 3, 5 laid along the outer peripheries of the zones 2, 4 within the half circles, respectively, so as to surround the zones 2, 4, respectively,
• zones 6, 7 along the outer peripheries of the zones 3, 5, between the outer periphery of the small diameter beam and a large diameter beam, extending along substantially half circumferential parts of the small diameter beam,
• zones 8, 9 extending along substantially half circumferential parts of the large diameter beam, respectively,
• a first zone which is a remaining zone other than the zones 2, 3, 4, 5, 6, 7, 8, 9 and including a diameter,
• wherein the direction of thee diameter included in the first zone 1 is at right angles to a tilt direction to be corrected.