A novel pickup head design for DVD-multi system

This paper introduces a novel holographic optical element (HOE) pattern des ign to generate focusing and tracking signal for using in digital versatile disc DVD-multi pickup heads. The digital verstile disk (DVD) multi drive w ill be able to read disks written in the DVD-ROM, DVD-video. DVD-audio, DVD -R/W, and DVD-R formats. DVD multi drive will also be able to write disks i n the DVD-RAM and DVD-RW/R formats. The HOE design provides the focusing er ror signal and both differential phase detection (DPD) and pushpull trackin g signals for DVD-ROM disks and rewritable land-groove disks. The HOE patte rn is divided into two main regions. The inner region is for focus detectio n and the outer region is for DPD and Pushpull tracking detection. In this study. a rotary actuator is used to reduce the tilt angle of the objective lens in the DVD-multi pickup head. The finite element method of the actuato r is studied to analyze the resonance of the structure and the magnetic fie ld of the voice coil motor.