| 摘要 |
PROBLEM TO BE SOLVED: To detect surface roughness of an object to be measured having big unevenness having a long period and a big variation in addition to minute unevenness.SOLUTION: An objective lens 305 is arranged on a slider 44 moving on the surface of an object to be measured OB while being in contact with the object, and the slider 44 is elastically supported by an optical head body 30 using a probe 40. A laser light from a laser light source 301 is gathered by an objective lens 305, and the surface of the object to be measured OB is irradiated with the laser light. Reflected light from the surface of the object to be measured OB is received by a photodetector 308, and a focus error signal is generated. A distance changed according to a distance between a focus position of the laser light and a surface position of the object to be measured OB is calculated using the focus error signal, and the size of unevenness on the surface of the object to be measured OB with respect to a reference surface is calculated by adding a variation of a relative position of the slider 44 with respect to the optical head body 30. |
