| 摘要 |
PURPOSE:To obtain a small-sized and low-cost device of high performance by constituting the device so that the polarized component generated by a recording medium is an approximately p-polarized light to a parallel planar plate and detecting an information signal, focusing error signal, and tracking error signal by a photoelectric conversion element. CONSTITUTION:A less means 19, an analyzer 21, and a photoelectric conversion element 22 are provided on the optical path of the light from a recording medium, and an approximately parallel planar plate 20 is provided on the optical path between the lens means 19 and the analyzer 21 obliquely to the light advancing direction. Then, the polarized component generated by the recording medium 5 is an approximately p-polarized light to the parallel planar plate 20 in contrast to the polarization direction of the light incident on the parallel planar plate 20. The information signal, the focusing error signal, and the tracking error signal are detected by a photoelectric conversion element 22. Since not only the Kerr rotation angle is increased double but also a servo optical system is constituted by the parallel planar plate 20 in this manner, an optical pickup is made small-sized and low-cost by the simple optical system and the small number of components. |
