US Patent 7894320 Optical pickup device and optical disc apparatus

An optical pickup device has: a light source; an objective lens that condenses laser light emitted from the light source on a recording layer of an optical disc; and a movable lens that is disposed between the light source and the objective lens and that is movable along the optical axis. The movable lens is moved to correct for spherical aberration. Between the light source and the objective lens, a RIM intensity adjusting element is also disposed that adjusts the RIM intensity by changing the range within which, as the movable lens is moved, the intensity of the laser light incident on the objective lens can be varied.