| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a clear output image when a palm print is taken. <P>SOLUTION: An FOP 1 includes a plurality of unit fibers 4 the respective optical axes of which are approximately parallel to each other, and an input end surface 2 and an output end surface 3 configured by assembling both end surfaces of the unit fibers 4, respectively. The FOP 1 has a conical shape having a height in the optical axis direction; the input end surface 2 configures the side surface of the conical shape; and the output end surface 3 configures the bottom surface of the conical shape. A light made incident from the input end surface 2 is output from the output end surface 3 when a palm or the like of a subject is brought into contact with the input end surface 2. The unit fiber 4 has a core 5 for propagating the light which is made incident from the input end surface 2, a cladding 6 for covering the external periphery of the core 5, and a light absorbing body 7 for absorbing the incident light while covering the external periphery of the cladding 6. The input end surface 2 is inclined with respect to the optical axis of the core 5 and the angle of inclination is set so that the light made incident from air into the core 5 does not generate total reflection at a boundary surface between the core 5 and the cladding 6. <P>COPYRIGHT: (C)2010,JPO&INPIT |
