| 摘要 |
PURPOSE:To achieve to make an optical head compact and furthermore, overall apparatus compact without requiring severity of a manufacturing accuracy of a reflecting mirror. CONSTITUTION:A part of the outer wall 35' of an optical head movable part is cut out, and a reflecting mirror 31' is mounted on its cutout surface. A semiconductor laser 21, a collimator lens 22, a beam shaping prism 23, an aperture 24, a 1/2 wavelength plate 25, a diffraction grating 26, a polarization beam splitter 27, a spherical lens 32, a cylindrical lens 33 and a photodetector 34 are disposed in an optical head fixed part. A surface reflecting mirror 28, a 1/4 wavelength plate 29 and an objective lens 30 are disposed in the movable part. |
