| 摘要 |
PROBLEM TO BE SOLVED: To obtain a device with less fitters in a photodetecting signal and capable of excellently reading out an information signal from an optical recording medium by controlling a light emission output of a light source with an output control circuit so that the jitters in the signal detected by a photodetector become minimum. SOLUTION: A photodetecting output outputted by a detector 6 is sent to a jitters detection circuit 7 and the jitters detection circuit 7 measures the jitters in the photodetecting output sent by the detector 6. The amount of such the jitters is affected by aberration caused by an objective lens 4 and a beam splitter plate 3 and is also affected by noise caused from a laser diode 1. The noise caused from the laser diode 1 is changed according to a light emission output of the laser diode 1. The jitters detection circuit 7 sends a signal showing the measured jitters amount to a laser drive circuit 2. The laser drive circuit 2 controls the light emission output of the laser diode 1. |
