| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical disk recording and reproducing device which can cancel push-pull offset in tracking of a push-pull system with a low cost. SOLUTION: An optical system a grating 27 having a groove of smaller area than a cross section of luminous flux of a light beam in an optical path between a laser diode 13 and an optical disk 1. Diffraction light is generated from luminous flux of a light beam by the grating 27, as a light beam being not diffracted by the grating 27 and diffracted light cause offset having the same phase, an optical disk recording and reproducing device can cancel offset of tracking using diffracted light and light beam being not diffracted. |
