| 摘要 |
PURPOSE:To perform jitter compensation simply by holding the level of quantity of light of a laser output beam constant during recording to an optical disk and varying only the pulse width of write pulses. CONSTITUTION:The pulse width of a pulse P4 applied to tracks within a range between diameter positions phi3-phi5 is equalized to the pulse width of the input write pulse P4, and the quantity of light at this time is set to Pw2 where the amount of jitters is zero. Respective annular areas phi1-phi3, phi3-phi5 and phi5-phi7 are areas sectioned by jitter permissible values of + or -DELTAT0 to center position tracks phi2, phi4 and phi6. A write pulse P2 whose pulse width is shortened by the generation amount +DELTAT6 of jitters is applied to a range phi1-phi3, and a pulse P6 whose pulse width is extended by the generation amount -DELTAT166 is applied to phi5-phi7. When recording pits formed by those write pulses are reproduced, reproduced g1, g2, q3¦q'3,q4,q5¦q'5,q6, and q7 are obtained corresping respective di ameter positions and all within a jitter permissible value range of + or -DELTAT0. |
