Laser Head And Signal Detection And Processing System

The optical pickup is a key part of digital optical disks. In order to further develop the techniques of digital optical disks and optical drivers, the optical pickup technology must be developed first. In present, however, the optical pickup technology of our country lays behind the advanced technology of the world. Therefore it is very important for us to develop the optical pickup technology. The actuator is the key part of the optical pickups. It is also the accurate servo driving mechanism of the optical system, and one of the important research subjects in the optical pickup field as well.In this thesis, the principles of optical pickup signal detecting and process system are analyzed in detail with emphases on the actuator magnetic circuit design and the computation of the magnetic induction intensity in working gap of the actuator. In the 4. 5S optical pickup design, in order to solve the problems of low movement sensitivity and high JITTER values, an optimum magnetic circuit structure is designed for the actuator according to theoretical analysis. The experiment results show that, for the new actuator, the focus movement sensitivity increases 70%, the tracking movement sensitivity increases 10%, and the requirement for the overall performance of the system has been achieved.