Patent ID: 7035191

Claim:
An optical pickup in an optical device compatible with first and second recording media having different formats, the optical pickup comprising: a light device module having a first light beam source and a second light beam source to selectively emit first and second light beams having different wavelengths which correspond to the respective first and second recording media, said light device to selectively emit the first and second light beams according to which one of the first and second recording media is received by the optical device; a hologram light coupler having a maximum pattern depth that is greater than or equal to 4,000 nm and less than or equal to 7,000 nm so as to separately guide the first and second light beams along a common optical path to the respective first and second recording media; an optical path changing unit to selectively alter an incident first and second light reflected from the respective first and second recording media to follow a reflected optical path different from the common optical path; and an objective lens disposed on the common optical path between said optical path changing unit and the respective first and second recording media to focus the selectively emitted first and second light beams on the respective first and second recording media; and a photodetector to receive the first and second light beams incident along the reflected optical path from said optical path changing unit, and to detect an information signal and error signals from the received first and second light beams, wherein the hologram light coupler is disposed between the light device module and the optical path changing unit.