Optical pickup and optical disk drive using same

An optical pickup for recording and/or reproducing information to and/or from a first optical disk of one type and a second optical disk of the other type, the optical pickup comprising:

• a first light source to emit a light beam of a first wavelength;
• a second light source to emit a light beam of a second wavelength different from the first wavelength;
• an objective lens to focus the light beam emitted from the first or second light source onto the signal recording surface of the optical disk;
• a liquid-crystal optical element provided between the first and second light sources and the objective lens to correct spherical aberration, astigmatism and coma by varying the refractive index thereof;
• and
• a photodetector to detect return light from the signal recording surface of the optical disk,
• the liquid-crystal optical element having a pair of electrodes disposed opposite to each other in the optical-axial direction;
• and
• the liquid-crystal optical element having a pattern to correct spherical aberration, pattern to correct astigmatism and a pattern to correct coma, the patterns being disposed dispersedly on the pair of electrodes to divide the electrode pair into a plurality of zones, and the plurality of zones resulted from division of the electrode pair by the patterns being used in combination to correct the spherical aberration, astigmatism and coma.

An optical disk drive including an optical pickup for recording and/or reproducing information to an optical disk and a disk rotation driving unit for rotating the optical disk, wherein:

• the optical pickup comprising:
• a light source to emit a light beam of a predetermined wavelength;
• an objective lens to focus the light beam emitted from the light source onto the signal recording surface of an optical disk;
• a liquid-crystal optical element provided between the light source and objective lens to correct spherical aberration, astigmatism and coma by varying the refractive index thereof;
• and
• a photodetector to detect return light from the signal recording surface of the optical disk,
• the liquid-crystal optical element having a pair of electrodes disposed opposite to each other in the optical-axial direction;
• and
• the liquid-crystal optical element having a pattern to correct spherical aberration, pattern to correct astigmatism and a pattern to correct coma, the patterns being disposed dispersedly on the pair of electrodes to divide the electrode pair into a plurality of zones, and the plurality of zones resulted from division of the electrode pair by the patterns being used in combination to correct the spherical aberration, astigmatism and coma.

An optical disk drive including an optical pickup for recording and/or reproducing information to first and second disks and a disk rotation driving unit for rotating the first or second optical disk, wherein:

• the optical pickup comprising:
• a first light source to emit a light beam of a first wavelength;
• a second light source to emit a light beam of a second wavelength different from the first wavelength;
• an objective lens to focus the light beam emitted from the first or second light source onto the signal recording surface of the optical disk;
• a liquid-crystal optical element provided between the first and second light sources and the objective lens to correct spherical aberration, astigmatism and coma by varying the refractive index thereof;
• and
• a photodetector to detect return light from the signal recording surface of the optical disk,
• the liquid-crystal optical element having a pair of electrodes disposed opposite to each other in the optical-axial direction;
• and
• the liquid-crystal optical element having a pattern to correct spherical aberration, pattern to correct astigmatism and a pattern to correct coma, the patterns being disposed dispersedly on the pair of electrodes to divide the electrode pair into a plurality of zones, and the plurality of zones resulted from division of the electrode pair by the patterns being used in combination to correct the spherical aberration, astigmatism and coma.