| 摘要 |
The present invention relates to the protection of relief impressions formed in order to store information on a data carrier which can be optically read out by transmission. The invention relates to a data carrier the relief impression in which is protected by at least one layer transparent vis-a-vis the read-out radiation. The protective layer has an index of refraction that differs from that of the data carrier, per se. Thus, a refractive boundary at the relief impression is maintained and the information encoded in the diffractive relief pattern is preserved. |
