Optical pickup using two-wavelength light source module and method for correcting position difference

Abstract

An optical pickup includes a light source module in which first and second light sources that emit first and second light beams of different wavelengths are integrated into a single package, an objective lens that focuses the first and second light beams to form a light spot on a recording surface of a recording medium, a light path changer that changes a path along which the first and second light beams propagate, a photodetector that receives the first and second light beams entered via the objective lens and the light path changer and detects an information signal and/or error signal, and an optical element disposed on a path along which the first and second light beams propagate to act as a lens with respect to only one of the first and second light beams so as to correct a position difference along a light propagation direction between the first and second light sources. Accordingly, it possible to correct a position difference along a light propagation axis between the two light sources in the light source module. Obtaining the same light propagation axis is made possible by using the optical element to make the two light propagation axes coincidental or by using a separate optical element to perform this function. This allows the optical pickup to be used for recording as well as for reproducing.