Optical pickup device and optical disc device

摘要

An optical pickup device has a first optical system including a double lens type lens unit having a forward lens arranged facing an optical disc and a backward lens having an optical axis coincident with the forward lens. The optical pickup device also has a second optical system including an objective lens and first and second gap detection photodetectors for detecting the separation between the signal readout surface of the optical disc and the forward lens of the double lens type lens unit. The optical pickup device also includes a bobbin provided with the double lens type lens unit of the first optical system and with the objective lens of the second optical system and an electromagnetic driving unit for driving the bobbin in a first direction parallel to the optical axis of the objective lens and that of the forward lens of the double lens type lens unit and in a second direction normal to the optical axes. With the optical pickup device, the objective lens unit can be improved in operational reliability and the device in its entirety can be reduced in size.