Optical pickup system and information recording and/or reproducing apparatus employing the same

An apparatus for accessing three different types of optical recording media, comprising:

• an optical pickup system 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 third light source emitting third light beams with a third wavelength greater than the second wavelength;
• a composite prism comprising a first prism facing the first and second light sources,
• a second prism facing the third light source, and a third prism for receiving the first, second and third light beams from the first and second prisms, wherein the first prism has a surface facing the first and second light sources, the surface defines first and second regions, and the second region has an aspherical surface to compensate aberration of the second light beams;
• a collimating lens disposed in a common optical path for collimating and transmitting the first, second and third light beams from the composite prism;
• and an objective lens also disposed in a common optical path for focusing the first, second and third light beams from the wavelength selector on the three different types of optical recording media;
• and
• a drive mechanism for changing a relative position between any one of the first, second and third optical recording media and the optical pickup system;
• and
• an electrical signal processor for receiving signals output from the optical pickup system and performing calculations on the signals to obtain desired information.

An apparatus for accessing multiple different optical recording media, said apparatus having an optical pickup system to obtain information from a selective one of said multiple different optical recording media, said optical pickup system further 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 said first wavelength;
• a third light source emitting third light beams with a third wavelength greater than said second wavelength;
• a composite prism facing said first, second and third light sources for receiving said first, second and third light beams therefrom respectively, said composite prism defining at least two aspheric surfaces used for passage of said second and third light beams respectively and exclusively;
• and
• an objective lens disposed next to said selective one of said multiple different optical recording media for receiving a corresponding one of said first, second and third light beams to said selective one of said multiple different optical recording media from said composite prism and transmitting said corresponding one of said first, second and third light beams to said selective one of said multiple different optical recording media.