| Autor: |
Ohtaki, Sakashi, Murao, Noriaki, Ogasawara, Masakazu, Iwasaki, Masayuki |
| Zdroj: |
Japanese Journal of Applied Physics; March 1999, Vol. 38 Issue: 3 p1744-1744, 1p |
| Abstrakt: |
We have studied the next-generation digital versatile disk (DVD) using a blue laser and investigated the application of a liquid crystal (LC) panel to the high-density disk. The LC panel can easily shift the optical path length of light beams making it possible to cancel out wavefront aberrations. First, the authors applied an LC panel to a tilt servo system. Compared with a mechanical tilt servo system, the LC tilt servo is expected to be more compact and reliable. We also developed a system for sensing the amount of disk tilt by comparing the signal levels of crosstalk from adjacent tracks. Consequently a tilt servo without any extra sensors was achieved. Another application of the LC panel is for the compensation of spherical aberrations. It was confirmed, by simulations and experiments, that the LC panel was practically useful for correcting disk thickness error which has been determined to become more serious when a blue laser was used. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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