A new measuring method of vertical degree between pick-up and disc of DVD drive

摘要

Vertical degree of pick-up and disc is an important factor that influences reading and writing date in DVD drive. Measuring and adjusting vertical degree of pick-up and disc is a key working procedure in DVD drive manufacture. Now, measuring method in actual production is an indirect measuring, which measure parallel between spindle motor and traverse. It's not very accuracy as there are error in pick-up assembles, The paper suggests a new method to measure vertical degree of pick-up and disc, new method measure vertical degree of pick-up and disc directly. The key of new method is measure position of laser from pick-up. A specialty optical circuit and fine CCD camera is need. The CCD camera is responsibility for collection information of laser image of pick-up and sends information to a computer. The specialty software responsibility for calculating position of laser and calculating incline angle between pick-up and disc. Because of characteristic of DVD drive manufacture, the algorithm calculating position of laser image must be design for accuracy and quickness. The paper suggests a specialty algorithm to calculating position of laser image. The algorithm is very accuracy and quickly, it can measure 0.05-degree incline angle error. The new method is helpful to automatic adjusting technique vertical degree of pick-up and disc.