| 摘要 |
PURPOSE:To secure a read direction over a wide range by a small readout window by giving a hologram such characteristics that the angles of scanning lines vary as the scanning lines float over the readout window. CONSTITUTION:At least two beltlike holograms 41a', 41b', and 42a' which cross one another are provided and a prescribed scanning pattern which contains plural scanning lines 46a, 46b, and 48a is formed in the readout window 60 of a scanner. The angles of the scanning lines forming the scanning pattern vary in a plane parallel to the readout window as the scanning lines float over the readout window 60. Consequently, the readout window of the hologram scanner which can reduce the thickness of a bar code reader can be reduced in size and the scanning lines constituting the scanning pattern can be extended uniformly in as many directions as possible because of the design of the holograms.
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