PICKUP DEVICE

摘要

A pickup device comprising a detection optical system including a photoetector (40) which receives the return light returned by reflection from a light spot obtained by condensing a light beam onto the track on the recording surface of an optical recording medium through an objective lens, and performs photoelectric conversion. The photoetector (40) has at least two light receiving sections (Det1-4) formed line-symmetrically with respect to a detection side cut line (RCL) which passes the optical axis of the return light and extends in parallel with the track. A cutting element (37) arranged on the optical path between the photoetector (40) and the objective lens includes at least two inside cut areas (C, D) formed line-symmetrically with respect to a deflection side cut line (DCL) which passes the optical axis of the return light and extends in parallel with the track, and at least two outside cut areas (A, B) formed line-symmetrically with respect to the deflection side cut line (DCL) on the peripheries of the inside cut areas (C, D). The inside cut areas (C, D) are formed to supply a part of a light beam from other than an overlap areas (LR) divided line-symmetrically by the deflection side cut line (DCL), respectively, to the light receiving sections (Det1-4) of the photoetector (40) while interchanging it across the detection side cut line (RCL) to become line-symmetrical with respect to the detection side cut line (RCL).