| 摘要 |
The present invention relates to a drive for accessing an optical record carrier (2) comprising means (4) for determining the type of record carrier, in particular for distinguishing a read-only record carrier from a recordable or rewritable record carrier having a wobbled groove in the lead-in zone, said means comprising: a DPD measuring unit (41) for measuring the differential phase detection (DPD) signal, a PP measuring unit (42) for measuring the push-pull (PP) signal in case no DPD signal could be measured, a wobble locking unit (43) for locking, in case a PP signal could be measured, to the wobble embedded in said wobbled groove using a first and/or a second polarity setting, and an indication unit (44) for generating a first indication signal indicating that the record carrier is a read-only record carrier if a DPD signal could be measured and that the record carrier is a recordable or rewritable record carrier if no DPD signal but a PP signal could be measured and if locking to the wobble has been successful. In a further embodiment a second indication signal in generated indicating the type of polarity in case of a recordable or rewritable record carrier. |
