摘要 |
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.
|