| 摘要 |
PURPOSE:To miniaturize an optical system and to reduce the weight of the titled head by using a Savart plate for a magneto-optical reproducing photodetector, and using a knife edge method for a servo-error signal optical system. CONSTITUTION:The titled head is provided with a semiconductor laser 1 being a light source, a collimator lens 2 for converging and irradiating a luminous flux emitted from the semiconductor laser onto the surface of a magneto-optical recording medium 6, a beam splitter 4 and an objective lens 5, a 1/2 wavelength plate 7 provided with a rotary mechanism for bringing the plane of polarization provided in the optical path of a reflected light from the beam splitter 4, to pi/4 rotation, a spherical lens 8, the Savart plate 9 for polarizing and splitting the luminous flux in parallel to the optical axis, a wedge prism 10 placed in the optical axis of one luminous flux in the polarized and split luminous fluxes, and a multi-split photodetector 11 for detecting the information signals from both the polarized and split luminous fluxes, respectively, and the multi-split photodetector 11 has a function for outputting a servo-error signal, and simultaneously, a recording information signal. In such a way, by simplifying a reproducing optical system, the magneto-optical recording and reproducing head can be further miniaturized to reduce the weight of the head.
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