| 摘要 |
A recording device records marks in a track on a record carrier via a beam of radiation. The record carrier has a preformed track pattern such as a wobbled pregroove having prepits for encoding record carrier information. The device has a head for generating a scanning spot on the track and a front-end unit coupled to the head for generating detector signals based on radiation reflected from the track, the detector signals including a left subdetector signal and a right sub-detector signal. The device has a demodulation unit for retrieving the record carrier information from the detector signals, which includes a radial modulation signal circuit (34). The circuit generates a radial modulation signal (66) based on a difference signal of the sub-detector signals (61,62) normalized by a sum signal of the sub detector signals, and generates the sum signal by adding a correction amount. Thereby overcompensation due to normalization is reduced.
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