| 摘要 |
PURPOSE:To provide an information recording method suitable for obtaining high- quality reproduction signals, by varying the trailing edge of a recording pulse width of recording laser beam according to the pulse width of a recording signal. CONSTITUTION:Laser beam from a semiconductor laser 3 is led through a magnifying lens 4, a half-mirror 5 and an objective lens 6 to condense the beam to a diameter of about 1 mum, and the condensed beam is cast on a recording medium 1 undergoing a change in structure under the action of heat such as laser beam, thereby recording. When signal pulse light such as the laser beam is cast on the recording medium to thermally change the structure of the medium 1 thereby recording a signal, the pulse width of a recording signal and the pulse width of the signal actually recorded in the medium often discord with each other. Namely, when the pulse width of the recording signal is varied, the relationship between the pulse width of the recording signal and the pulse width of the recorded signal is such that the leading edges of both pulses coincide with each other but the pulse width of the recorded signal is shorter than the pulse width of the recording signal. Therefore, by retarding the fall of the recording signal pulse, it is possible to cause the pulse width of the signal recorded on the recording medium to accord with the pulse width of the recording signal. |
