| 摘要 |
PROBLEM TO BE SOLVED: To realize high optical performance during reading by lowering the light emission output of a laser diode compared with writing when an information signal is read by an optical recording medium and enlarging the dispersing angle of a luminous flux. SOLUTION: In this optical pickup device, for a laser diode 1, a light emission outputs is made lower compared with writing an information signal for an optical recording medium 101 when the information signal is read from the optical recording medium 101, and the dispersing angle of an emitted luminous flux R is increased. Thus, in this optical pickup device, the efficiency of coupling between the laser diode 1 and an optical means is lower for reading the information signal than for writing the same, and a beam spot formed by the convergence of the luminous flux R on the signal recording layer of the medium 101 is made small. |
