Optical pickup head and information recording and/or reproducing device incorporating same

An optical pickup head for a high density recording and/or reproducing device which is compatible with at least first and second optical recording media, comprising:

• a first light source emitting first light beams with a first wavelength;
• a second light source emitting second light beams with a second wavelength greater than the first wavelength;
• a prism unit including a first prism facing the first light source, a second prism facing the second light source, and a third prism beside the first and second prisms;
• a collimating lens for collimating incident first and second light beams;
• an objective lens for receiving the first and second light beams and transmitting the first and second light beams to the at least first and second optical recording media;
• and
• a wavelength selector located between the collimating lens and the objective lens, for selectively passing a portion of the second light beams;
• wherein, the prism unit further includes an aspherical surface, and only the second light beams pass through the aspherical surface.

An information recording and reproducing apparatus compatible with a selective one of first and second optical recording media, comprising:

• an optical pickup head, comprising:
• a first light source emitting first light beams with a first wavelength;
• a second light source emitting second light beams with a second wavelength greater than the first wavelength;
• a prism unit including a first portion facing the first light source adapted to receive the first light beams emitted by the first light source, a second portion facing the second light source adapted to receive the second light beams emitted by the second light source, and an aspherical surface for the second light beams to pass therethrough;
• and
• an objective lens for receiving the first and second light beams from the prism unit and transmitting the first and second light beams to the selective one of the first and second optical recording media;
• a drive mechanism for changing a relative position between any one of the at least first and second optical recording media and the optical pickup head;
• and
• an electrical signal processor for receiving signals output from the optical pickup head and performing calculations to obtain desired information.