Recent improvements to optical disk drive technology

Several improvements to the optical disk drive and key parts have been carried out to enhance their function, storage density, capacity, data rate and reduce access time in recent years in the Optical Memory National Engineering Research Center (OMNERC). Approach for research on both of optical system and mechanic-electronic servo system are also reported in this paper. OMNERC of China started research and development on optical disk drive in the early 80's. In the past 15 years, many kinds of drives as phase-change erasable disk drive, CD-ROM drive, V-CD player etc. have been finished and some results of them have been playing important role in optical storage products manufacturing industry. In recent 5 years OMNERC has made the new optical drive model and some major technology research and development from the China national 8th five years science and technology development plan. The objective of this major subject is to make research and development on new generation multifunctional optical disk drive, especially on photo/thermo effect read, write and erase technology and drive as well as application systems. They are following projects: designing larger numerical aperture of objective lens used to enhance resolution and storage density, simplifying moving part of optical head to reduce its weight with holographic and other diffraction elements, increasing autofocusing and seeking precision, speed and proper frequency width of driving system, developing dual laser beams multifunctional optical head which is suitable for various inorganic and organic write once or erasable media, improving the data rate and reliability of storage data.