| 摘要 |
PURPOSE:To enable generation of distortion of a recording medium to be reduced and signal deterioration due to repetitive recording to be reduced by setting an quantity of light at a region other than a recording region where signal is recorded to 1/4 or 3/4 of the quantity of light of the recording region. CONSTITUTION:An quantity of light is set to an intermediate value between an quantity of peak light and a quantity of reproduction light without reducing the quantity of light to the quantity of reproduction light. Also, the quantity of reproduction is given near an ID region 2. Then, 50mum region is given immediately after recording region and then repetitive recording experiment is performed while changing the setting of the quantity of light. In this case, by setting the quantity of light at a region immediately before or after, a large change in the quantity of light at the time of recording at a tip and end portions of the recording region can be reduced, unbalance in amount of heat near this area is reduced, thus preventing distortion from occurring easily at a recording medium and enabling signal deterioration due to repetitive recording to be restricted. |
