| 摘要 |
PURPOSE: A multi-layered luminescent security thread is provided to comprise multi-layered fluorescent substrates having wavelengths different each other. CONSTITUTION: A multi-layered luminescent security thread comprises multi-layered fluorescent substrate having different wavelengths from each other. The florescent substrate has two or more light-emitting wavelengths selected from red, blue, green, and yellow florescence. The red-fluorescent substance emits light in the wavelengths of 610-690 nm. |
