| 摘要 |
PURPOSE:To attain the clear image pickup of a fingerprint, etc., by making incident a laser light through a coherence removing means onto a transparent flat plate and removing and image-picking up the light to execute the total reflection on a rugged interface through a hologram. CONSTITUTION:The laser light from a laser light source 8 comes to be a laser light 8b without coherence through a coherence removing means 9 such as a rotating glass disk or a liquid crystal, is made incident on a transparent flat plate 5 where a hand and finger 7 of the rugged surface for detection is pressured, the total reflection is executed on the boundary surface of a convex surface 7a and a concaved surface 7b and comes to be a reflecting light 8c without a spectral noise since scattering due to the coherence does not exist. The reflecting light 8c is removed and emitted from the flat plate 5 by a hologram 6, and an emitting light 8d of a clear fingerprint image without spectral noise influence is image-picked up by a TV camera 4.
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