Optical Pickup for Recording to Dual-Layer 2x-Speed Blu-Ray Disc, DVD and Compact Disc

An ordinary half-height size optical pickup with high light-use efficiency for Blu-ray Discs (BDs) has been realized. It has two objective lenses arranged tangentially. Although one of the objective lenses, BD objective lens, does not follow the line that passes thorough the center of the spindle motor, stable tracking-error detection has been achieved by enhancing a one-beam method. This pickup has a beam shaper which changes a divergent angle of light with high magnification. Although beam shapers are sensitive to a positional error, our pickup accomplished stable positioning by introducing a new structure.