| 摘要 |
The present invention relates to a recording or replay device, and to a method for recognizing a focussing status. The object of the invention is to provide a method of this type and a recording or replay device, with the facility of producing significant astigmatism in the reflected light beam (15) simply and cost-efficiently without elaborate alignment. This object is achieved by the use of a birefringent element (23, 24). The invention is, in particular, suitable for use in a recording or replay device for writing to or playing back optical recording media (11) such as CDs, video discs, DVDs and the like.
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