| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical pickup capable of sharing/reproducing plural optical disks with different thickness. SOLUTION: This optical pickup is provided with at least a laser light source 1, a beam splitter 2, an objective lens 4, a photodetector 6 and a diffraction type optical element lens 8, and the diffraction type optical element lens 8 changing diffractive efficiency by application of a voltage is inserted between the laser light source 1 and the objective lens 4. When the optical disk 7 of one side thickness is reproduced, the voltage is applied to the diffraction type optical element lens 8, and a refractive index is changed, and when the optical disk 7 of the other side thickness is reproduced, the voltage isn't applied to the diffraction type optical element lens 8, and the refractive index isn't changed. |
