Optical pickup device

DETAILED DESCRIPTION It is an object of the present invention to provide a more simplified and minimized optical pickup device capable of easily realizing recording/reproducing information on/from an optical disc having at least two data storing layers on one side thereof.
In order to achieve the above mentioned object, an optical pickup device according to the present invention comprises first and second laser beam sources for generating first and second laser beams having planes of the same polarization in order to record/reproduce information recorded on an optical disc, the first and second laser beam sources being opposite to each other, a beam splitter means for total reflecting or total transmitting the first and second laser beams depending to the polarization of the beams, the beam splitter means located on optical paths of the first and second laser beams, a polarization converting means located on optical paths of the second laser beams total reflected by the beam splitter means so that the second laser beam can be reflected and converted in its polarizing plane and thus the second laser beam can proceed along the optical path of the first laser beam, a condensing means for focusing the first and second laser beams onto the optical disc when the laser beams proceed toward the optical disc via the splitter means.
The above-mentioned beam splitter means preferably may be a prism of a cubic type in which a dielectric coating layer for selectively total reflecting or total transmitting depending to a polarizing state of an incident beam is formed at a diagonal surface of the prism.
The above-mentioned beam splitter means preferably may be a dielectric coating plate arranged with an incline of 45.
degree.
on the basis of a line connecting first and second laser beam sources.
That is, the above-mentioned beam splitter means preferably may be only a dielectric coating plate positioned at the diagonal surface without the prism of the cubic type.
The polarization of the first and second laser beam are so determined that the laser beams before passing through the polarization converting means are total reflected by the beam splitter means and the laser beams after passing through the polarization converting means are total transmitted by the beam splitter means