| 摘要 |
PURPOSE:To complete the recording to a recording medium in a required minimum time by detecting a recording error at the same time in recording information to the recording medium. CONSTITUTION:Several tens % of the light irradiated on a recording medium 8 are reflected. The reflected light is collimated into a parallel light by an objective lens 5, the light passes through a 1/4 wavelength plate 4 and its optical path is bent by 90 deg. by a polarized beam splitter 3 and focused onto a photodetector 7 through a focus lens 6. An output of the photodetector 7 enters an envelope fault detecting section 14, where an envelope signal whose envelope exceeds rapidly the usual envelope fluctuation and gets larger abnormally or gets smaller abnormally rapidly is detected. If the reflectance from the medium 8 is changed remarkably due to a damage to the recording medium 8, since the envelope signal fault is detected, it is discriminated that the recording medium recording sector is a recording disable sector, and a control section 11 records the same information stored in a recording element onto a sector next to the bad sector by the same procedure again.
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