| 摘要 |
PURPOSE:To accurately monitor each light source and accurately control the light emission output with a simple constitution with respect to the optical information recording and reproducing device where luminous fluxes from plural light sources are used to form plural spots on an information recording medium and the light emission outputs of light sources are controlled by a front monitor. CONSTITUTION:Luminous fluxes emitted from two light emission points 1, 2 of a semiconductor laser diode array are converged and are thrown to an optical information recording medium 6 through a collimator lens 3 and an objective lens 5 to form plural recording and reproducing light spots. Luminous fluxes are taken out from this optical path by a polarizing beam splitter 4 and are made incident on a 2-divided photodetector 8 through a condenser lens 7. The photodetector 8 is arranged in the focal surface of the condenser lens 7, and two luminous fluxes are separated and converged and are made incident on respective light reception parts of the photodetector 8. |
