Abstract

The high gain servo controller with complex zeros was proposed[1]. The controller can realize a much higher gain with the same servo bandwidth. We applied the controller to Blu-ray disc drives, and confirmed decrease of servo error and improvement of a resistance to vibration. On the other hand, we observed the controller increased an overshoot of an initial value response. We applied the initial value compensation [2], and confirmed suppression of the overshoot.

© 2007 Optical Society of America