| 摘要 |
PURPOSE:To decrease the attenuation of amount of laser light, by providing a laser light source so as to keep the oscillating plane of its linearly polarized light perpendicular to a plane including a normal of a fixed mirror and a ray axis of the laser light. CONSTITUTION:The linearly polarized light laser light source 17 of an optical reader is equipped with a platform 16 so that a specified plane of polarization of the fixed mirror 18 and the oscillating plane of the linearly polarized light are made perpendicular. In a reflecting plane 30 of a beam splitter 22, the normal of this reflecting plane and the specified plane of polarization including the ray axis of the linearly polarized light laser are parallel with the oscillating plane of the linearly polarized light. The laser light from the beam splitter 22 becomes a circularly polarized laser light through a 1/4-wavelength plane 23 and reaches a recording plane. Thus, the laser lght is prevented from being reflected on the reflecting plane of the beam splitter as less as possible and the attenuation of amount of laser light is prevented. |
