| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin and low-cost optical pickup device by omitting an external tilt sensor. SOLUTION: While a semiconductor laser element 11 emits a light, and a laser beam 24 of 650 nm is emitted as a signal light, a semiconductor laser element 21 is caused to emit a light, thus emitting a laser beam 25 of 780 nm, and by using a laser beam 25a having a beam diameter reduced by a beam diameter reducing mechanism part 23 as a tilt detecting light, the tilting of an optical disk 1 is detected. |
