Optical Pickup Apparatus

Abstract

An optical pickup apparatus includes: a laser diode configured to generate a laser beam; and an objective lens having an annular diffraction zone formed on an incident surface thereof on which the laser beam is incident, the annular diffraction zone being a zone configured to focus the laser beam on each of signal recording layers of first to third optical discs so that a signal recorded in each of the signal recording layers of the first to third optical discs are read, the first optical disc having the signal recording layer at a first distance from a surface thereof, the second optical disc having the signal recording layer at a second distance longer than the first distance from a surface thereof, the third optical disc having the signal recording layer at a third distance longer than the first distance and shorter than the second distance from a surface thereof.

Dependencies are inferred from the claim text.