| 摘要 |
The invention provides a collimator comprising a prismatic layer stack. The prismatic layer stack comprises a first prismatic layer comprising ID arranged first prisms, with first prism tops having first prism top angels, and first grooves, having first groove angles; and a second prismatic layer comprising ID arranged second prisms, with second prism tops having second prism top angels, and second grooves, having second groove angles. The first prismatic layer and the second prismatic layer are in a crossed configuration. Further, the first and second prism tops of the first and the second prismatic layers point in the same direction. The first and second prism top angels and the first and second groove angles are selected from the range of 120-160°. |
