| 摘要 |
PURPOSE:To decrease a jitter, and to raise the reliability of a reproducing signal by shortening the width of a light emitting pulse of a laser condensing beam by the time corresponding to 5-30% of a half-amplitude level of the laser condensing beam, and irradiating it. CONSTITUTION:When pits 11, 13 and 15 are recorded, width of a light emitting pulse of a laser condensing beam 6 to be irradiated is shortened by the time corresponding to 5%-30% of a half-amplitude level of the condensing beam and it is irradiated. That is to say, by delaying the timing of a rise part A of the light emitting pulse, the width of the light emitting pulse is shortened, and the pit is formed by this shortened light emitting pulse. Length of the pit which has been formed by the shortened light emitting pulse becomes a little longer than the width of the light emitting pulse, since the laser condensing beam has a size of about 0.8mum-1mum by the half-amplitude level, and a pit of a desired length can be obtained. In this way, the generation of a jitter which becomes the cause of an error of a reproducing signal can be decreased, the reproducing signal having a high reliability can be obtained. |
