摘要 |
The invention provides an efficient reading device in which, even if one radiation beam should fail, no information is lost and the information can still be read out without time-consuming recurring operations. The present invention solves this problem by providing a reading device (Fig. 5A) and a means (Fig. 4) for forming read-out spots (A, B, C, D, E) that are built up by multiple radiation beams from the radiation source (4). This has the advantage that each read-out spot will have energy contributions from different radiation beams and, should one radiation beam break down, the intensity of some of the read-out spots may indeed diminish, but the information can still be read out thanks to the contributions from other radiation beams.
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