US Patent 7903507 Optical pickup device and method of laying out the same

An optical pickup device is provided, in which, supposing that an angle formed by the meeting of a straight line connecting a center of an optical disk and an accessing position of an HD objective lens with a diameter L of the optical disk is a track angle θ1, an oscillation angle α of an optical system including an HD laser, an HD half mirror, and an HD sensor, and a distance z of the HD objective lens are set so as to satisfy α−(θ1max+θ1min)/2=±45°, where θ1max is the track angle θ1 when the HD objective lens is positioned at an innermost circumference of the optical disk, and θ1min is the track angle θ1 when the HD objective lens is positioned at an outermost circumference of the optical disk.