To provide a paper sheet determination device capable of accurately detecting ultraviolet rays reflected by a paper sheet and fluorescence emitted from the paper sheet by irradiating the paper sheet with ultraviolet rays.
In this paper determination device 1, ultraviolet light L1 emitted from an ultraviolet LED 13 is sequentially transmitted through a half mirror 16 and a visible ray reflection filter 19 to be radiated to a bill S. When fluorescence light L3 is emitted from the bill S by the ultraviolet radiation, a photosensor 23 receives the fluorescence light L3 advancing upward over an optical axis A and reflected by the filter 19. A photosensor 22 receives ultraviolet light L2 advancing upward over the optical axis A and reflected by the half mirror 16. In this way, the ultraviolet light L2 and the fluorescent light 3 advancing over the same optical axis A is received, and consequently, the ultraviolet light L2 and the fluorescent light L3 can be detected precisely even if the bill 3 is wrinkled/bent.
Tatsuya Shioda
Shiro Terasaki