| 摘要 |
PURPOSE:To provide an optical head device capable of easily adjusting the position of the photodetector by arranging an optical divider having plural areas for respectively leading reflected light from an information recording face to different photodetectors. CONSTITUTION:A light beam from a laser light source 31 is made incident upon the optical divider 41 constituted by forming a diffraction grating 44 between bases 42, 43 through a collimeter lens 32. The incident light beam is directly transmitted through the divider 41, made incident upon a lambda/4 plate 34 and converted into a circularly polarized light and then the polarized light is converged upon an information recording face 37 by an objective lens 35 through a disk base 36. A light beam reflected on the recording face 37 is transmitted again through the lambda/4 plate 34 and converted into polarized light having a polarizing face rectangular to an incident face and the polarized light is made incident upon the divider 41. Reflected light from the divider 41 is diffracted or reflected by the grating 44, led through the base 43 while repeating full reflection and then made incident upon photodetectors 39, 40. Thus, a compact and light-weight device capable of easily adjusting the position of its photodetector can be provided. |
