OPTICAL ELEMENT, OPTICAL PICKUP DEVICE, AND OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To eliminate the need for applying an AR coat to a cover layer on the recording layer of an optical record medium by forming a magnetic field generation means on a surface that opposes the optical record medium of a lens and forming an electrode for detecting capacitance with respect to the optical record medium at the outer-periphery region. SOLUTION: An electrode S for detecting capacitance to a magnetooptical disk 2 is formed at the outer-periphery region of a spiral-shaped coil part 46 on a surface that opposes the magnetooptical disk 2 of a coil-supporting substrate 44. The electrode S is divided into a plurality of portions for each specific region. For example, the electrode S is divided into two portions concentrically. The outer-periphery region of the coil part 46 that is a magnetic field generation element is provided with an optical element with an electrode for detecting the capacitance at an area to the magnetooptical disk 2. Therefore, by measuring the capacitance between the electrode S and the magnetooptical disk 2, the distance between the electrode S and the magnetooptical disk 2 can be set to preset distance.