OPTICAL HEAD, ASSEMBLING METHOD OF OPTICAL HEAD AND OPTICAL RECORDER/REPRODUCER

摘要

An optical head performing correction on spherical aberration by controlling the degree of divergence of incident light, wherein good recording/reproducing is possible without any coma caused by spherical aberration correction. The optical head for recording/reproducing a signal onto/from an optical recording medium (9) comprises a light source (1), an objective lens (8) for condensing light emitted from the light source (1) onto the optical recording medium (9), a collimator lens (4) for correcting spherical aberration occurring on the optical recording medium by controlling the degree of divergence of light incident to the objective lens (8), and a coma correction element (6) arranged between the light source (1) and the objective lens (8) and correcting coma occurring on the optical recording medium (9) due to the optical system of the optical head including at least the objective lens (8), wherein the objective lens (8) is arranged such that its optical axis is parallel with the optical axis of light entering the objective lens (8).