摘要 |
A diffusing screen (50, 50', 50'', 102) of a transmission hologram (54, 80, 94, 112) located adjacent to a diffraction optics directional diffusing screen (52, 86, 92, 114) supresses zero-order light from the diffusing screen thereby providing a device having the advantages of a directional diffusing screen but which does not have the disadvantages associated with zero-order light.
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