Sheets fluorescence detecting sensor

摘要

A paper sheet fluorescence sensor 10 utilizes an ultraviolet-reflecting filter 30 in order to orthogonally irradiate a conveying path 4 with an ultraviolet ray and appropriately receive fluorescence from a paper sheet 7. The ultraviolet-reflecting filter 30 reflects light emitted from an ultraviolet light source 12, so as to produce light having an optical axis R2 orthogonal to the conveying path 4 of the paper sheet 7. The light transmitted through the ultraviolet-reflecting filter 30 is received by a fluorescence-receiving device 16. An ultraviolet-transmitting filter 15 is disposed between the ultraviolet-reflecting filter 30 and the ultraviolet light source 12, so that the light reflected by the ultraviolet-reflecting filter 30 attains a higher ultraviolet content, thereby improving the light-receiving accuracy.