| 摘要 |
Optically readable information carriers in disk form, for example video disks, digital audio or data storage disks, are generally produced by the transfer moulding process. In this case, during the course of their production, defects can occur in the information area during the successive operating steps due to material inclusions, small bubbles and surface damage, which cause falsifications of the information content even when of the order of magnitude of just a few micrometers. Even birefringent characteristics of the substrate disk can result in such informational falsifications. To test for such defects, a compact testing device is specified, which device operates with polarisation filters and in which the information carrier (5) to be tested is secured on a raised rest (3) in a peg arrangement (4), a covering is created in the form of a hinge-opening lid part (6) and a filter plate (11) which can be swung out from the lid part, and in which the bottom (8) of the lid part represents a first polarisation filter, to which a similar polarisation filter is assigned in the form of the filter plate. <IMAGE>
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