| 摘要 |
PURPOSE:To reduce number of components and adjusting points by emitting two polarized luminous fluxes split by a thin film polarized beam splitter in the same direction so as to integrate two photodetectors. CONSTITUTION:A horizontal linearly polarized light 2 emitted from a semiconductor laser 1 is emitted onto a vertical magnetization film 7 of a disk 6. The reflected light 8 is reflected on a half prism 4 and its reflected light 9 is made incident in the polarized beam splitter 10. The incident light is split point P polarized light 20 and S polarized light 21 by the thin film deflection split face 16. The S polarized light 21 is reflected further by the reflecting face 19 and emitted in the same direction as the P polarized light 20. The deflected direction of the light 9 is that the P polarized light component in the P polarized light 20 is increased in a region having no information recording, conversely the S polarized light component of the S polarized light 20 is increased in the information recording region. Then the difference of the output between the photodetector elements 12a and 12b of the photodetector 12 is taken by a differential circuit 13 to obtain a reproducing signal 14. Through the constitution above, the elements 12a, 12b are integrated and number of components is reduced.
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