| 摘要 |
PURPOSE:To increase a rotational angle on a plane of polarization of transmission light, and to elevate an S/N ratio of a reproducing signal, by making a light beam obliquely incident to an optical recording medium from a light source side plural times. CONSTITUTION:A light beam from a linear polarized laser light source 1 is made incident to a half-mirror 2 at an incident angle 50 deg., and its reflected ray forms a focus on an optical magnetic recording medium 5 through a condensing lens 3. An incident angle to the medium surface in this case is 10 deg.. The light beam reflected by the medium surface is made incident vertically to a mirror 6 through the lens 3, is turned back, is made incident to the medium 5 at an incident angle 10 deg. once again, and the reflected light beam is detected by an optical detecting part 7. Accordingly, the light beam is made incident two times, by which rotational angle of the reflected ray can be set to two times. An S/N ratio of a reproducing signal is in proportion to the rotational angle, therefore, the S/N ratio can be elevated by setting the rotational angle to two times. |
