Optical pickup using an optical phase plate

An optical pickup apparatus for at least two recording media, which are different in distance from an optical pickup to an information recording surface and using light beams for recording and reading information, the optical pickup apparatus comprising;

• a light source to emit a light beam;
• an objective lens divided into an inner region, a phase shift region and an outer region, wherein said light beam passing through the inner region always forms a beam spot on the information recording surface in an optical recording medium regardless of the kind of information recording medium, and the phase shift region shifts a phase of said light beam for forming the beam spot on the information recording surface for a particular type of optical recording medium;
• optical detection means for detecting light reflected from at least one of the two recording media;
• and
• a beam splitter for transmitting/reflecting light from said light source toward said objective lens and for reflecting/transmitting light reflected from the at least one of the two recording media toward said optical detection means.

An optical pickup apparatus for at least two recording media, which are different in distance from an optical pickup to an information recording surface and using light beams for recording and reading information, the optical pickup apparatus comprising;

• an objective lens divided into an inner region, a phase shift region and an outer region, wherein a light beam passing through the inner region always forms a beam spot on the information recording surface in an optical recording medium regardless of the kind of information recording medium, and the phase shift region shifts a phase of the light beam for forming the beam spot on the information recording surface for a particular type of optical recording medium;
• optical detection means for detecting light reflected from at least one of the two recording media;
• and
• a beam splitter for transmitting/reflecting light from a light source toward said objective lens and for reflecting/transmitting light reflected from the at least one of the two recording media toward said optical detection means.

An optical pickup apparatus for at least two recording media, which are different in distance from an optical pickup to an information recording surface and using light beams for recording and reading information, the optical pickup apparatus comprising;

• a light source to emit a light beam;
• a phase shifter which receives said light beam to shift the phase of said light beam;
• an objective lens which receives said light beam transmitted by said phase shifter to focus said light beam on the two recording media having a different thickness;
• optical detection means for detecting light reflected from at least one of the two recording media;
• and
• a beam splitter for transmitting/reflecting light from said light source toward said objective lens and for reflecting/transmitting light reflected from the at least one of the two recording media toward said optical detection means.

An optical pickup apparatus for at least two recording media, which are different in distance from an optical pickup to an information recording surface and using light beams for recording and reading information, the optical pickup apparatus comprising;

• a phase shifter which receives a light beam to shift the phase of the light beam to be transmitted to said objective lens;
• an objective lens which receives said light beam transmitted by said phase shifter to focus said light beam on the two recording media having a different thickness;
• an optical detector which detects light reflected from at least one of the two recording media;
• and
• a beam splitter for transmitting/reflecting light from a light source toward said objective lens and for reflecting/transmitting light reflected from the at least one of the two recording media toward said optical detector.