Optical disk apparatus and control method for controlling distance between a head and a disk

A method for controlling an optical disk apparatus, the method comprising:

• (a) a step of causing a head to approach a disk, the head being disposed so as to face the disk on which a signal is recordable, the head being configured to condense light output from a light source onto the disk as near-field light;
• (b) a step of nearly stopping the head that is approaching the disk at a position at which a distance from the disk is a first distance at which the light is condensed on the disk by the head as the near-field light;
• (c) a step of detecting if the distance between the head and the disk is the first distance, wherein the detecting step includes detecting a total-reflection return-light quantity for detecting the distance between the head and the disk;
• and
• (d) a step of controlling the distance between the head and the disk based on a detection signal detected at the step (c) such that the distance therebetween is a second distance under a condition in which the light is condensed on the disk as the near-field light.

An optical disk apparatus, comprising:

• a light source configured to output light;
• a head disposed so as to face a disk on which a signal is recordable, the head being configured to condense light output from the light source onto the disk as near-field light;
• a distance adjusting mechanism configured to adjust a distance between the head and the disk;
• a first controller configured to control movement of the head so as to approach the disk to and nearly stop at a first position, the first distance being a distance at which the light is condensed on the disk by the head as the near-field light;
• a detector configured to detect if the distance is the first distance, wherein the detector is configured to detect a total-reflection return-light quantity for detecting the distance between the head and the disk;
• and
• a second controller configured to control the distance adjusting mechanism based on a signal from the detector so that the distance between the head and the disk is kept constant under a condition in which the light is condensed on the disk as the near-field light.