| 摘要 |
PROBLEM TO BE SOLVED: To provide the optical pickup in which the luminous flux emitted from a light source is efficiently made incident on a converging lens and the electric power consumption is suitably reduced. SOLUTION: The optical pickup device is provided with a semiconductor laser element 2, a tripartite diffraction grating 3, which has a diffraction surface to diffract laser beams B emitted from the element 2 into ±1st order diffracted beams, and a converging lens 5 which irradiates the ±1st order diffracted beams that diffracted by the grating 3 on an optical disk. The diffraction surface has a first region (3a) which, does not diffract the luminous flux emitted from the element 2 into -1st order diffracted beams and diffracts into +1st order diffracted beams and makes the beams incident on the lens 5, a second region (3b) which does not diffract laser beams B emitted from the element 2 into +1st order diffracted beams and diffracts into -1st order diffracted beams and makes the beams incident on the lens 5, and a third region (3c) which diffracts the beams B into ±1st order diffracted beams and makes the beams incident on the lens 5. |
