Stable Servo System of Digital Versatile Disk Player against Defects

In this paper, a method for improving the tracking a servo performance at damaged portions of a digital versatile disk (DVD) disk of a DVD player, is presented. In this study, disturbance due to detection delay at the defective portion, one of the causes of degraded tracking servo performance at the defective portion is considered, and the double impulse method to negate the influence of disturbance on the tracking actuator is presented.