1 D. H. Yeom is with the Samsung Electronics Co. Ltd., Suwon, Korea (email: email@example.com). Abstract — An adaptive PLL is proposed to improve the readability of ODD. The proposed PLL is designed by using Kalman filter and implemented in a commercial ODD. Contrary to the conventional fixed PLL, the adaptive PLL can meet flexibly various situations such as eccentricity, deflection, and defect of rotating discs. The experimental results show that the proposed adaptive PLL is superior to the conventional fixed PLL.