| 摘要 |
The fluorescent mark reader has electroluminescent diodes (22) positioned to illuminate the fluorescent marking on the surface of the postal item, as they appear in a window (14) formed in a guide (12) for the postal item (10). These diodes are positioned on either side of the window, directing light at an angle onto the surface. An optical collector (18) is positioned directly above the surface carrying the fluorescent marking. The light collected from the surface is passed to photodetectors. The optical collector is formed from cylindrical lenses with graded index, reducing price and increasing photometric efficiency.
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