| 摘要 |
<p>An optical disc system records a desired data, particularly using a write once read many optical disc, so that the life time of the light source can be extended. An optical disc system controls the pulse width control circuit 72 on the basis of the asymmetry detecting results (48). Thus, the radiation time of the light beam L1 is controlled such that the asymmetry is kept to the optimum value. <IMAGE></p> |
