| 摘要 |
PURPOSE:To easily recognize the accumulation of dust, etc., on a pick-up section and to accurately operate a maintenance. CONSTITUTION:A returning light from a magneto-optical disk 1 is divided into a P wave polarized light component and an S wave polarized light component at an optical pick-up section 3, the levels of the P wave polarized light and the S wave polarized light are respectively detected by a first photo detector 4 and a second photo detector 5 and at a dust detector 6, a level difference between the P wave and S wave polarized light components detected by the fist and second photo detectors 4 and 5. This level difference and a threshold level which is lower than a level difference between the P wave and S wave poplarized light components when no dust is accumulated on the pick-up section 3 are compared and a controlling is operated by a system controller 7 so as to turn a warning lamp 17 on when this level difference is larger than a specified level. |
