Abstract: A paper sheet fluorescence sensor utilizes an ultraviolet-reflecting filter to orthogonally irradiate a conveying path with ultraviolet light and receive fluorescence from a paper sheet. The ultraviolet-reflecting filter reflects ultraviolet light emitted from an ultraviolet light source, to produce light having an optical axis orthogonal to the conveying path of the paper sheet. The light transmitted through the ultraviolet-reflecting filter is detected by a fluorescence detecting device. An ultraviolet-transmitting filter is disposed between the ultraviolet-reflecting filter and the ultraviolet light source, so that the light reflected by the ultraviolet-reflecting filter attains a higher ultraviolet content, thereby improving light-detection accuracy.

Abstract: In the accurate inspection of a paper sheet (for example, the type and authenticity of banknotes) light incident on the paper sheet that is being transported is controlled to be constant. To achieve such control, in accordance with the present invention, an illumination monitor is disposed facing an illumination window, and the light reflected by an inner surface of the illumination window is detected by the illumination monitor. Since, in this configuration, the illumination monitor faces the illumination window, the illumination monitor has a monitor region on a transportation path. The illumination monitor is directed toward the illumination window so that the monitor region is positioned outside an illumination region formed by a light-emitting element, thereby preventing the illumination monitor from picking up the light reflected from a transportation path of the paper sheet.

Abstract: 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.

Abstract: The accurate inspection of a paper sheet (for example the type and authenticity of banknotes) may be impossible unless the light incident on the paper sheet that is being transported is controlled in a constant state. To achieve such control, in accordance with the present invention, an illumination monitor is disposed so as to face an illumination window, and the light reflected by the inner surface of the illumination window is received by the illumination monitor. Since in this configuration the illumination monitor faces the illumination window, the illumination monitor has a monitor region S on a transportation path. The illumination monitor is directed toward the illumination window so that the monitor region S is positioned outside an illumination region R formed by the light-emitting element, thereby preventing the illumination monitor from picking up the light reflected from the transportation pass.