Patent ID: 6881962
Filing Date: 2005-04-19
Classification: G01N,G06K,G07D

Abstract:
1. A paper fluorescence detection sensor which detects fluorescent light generated from paper sheets by illuminating the paper sheets with light as the paper sheets are being transported, comprising: a case; a light-emitting element which is housed in said case, and which forms an illumination region on a transportation path of paper sheets by emitting light toward the transportation path via an illumination window, said light-emitting element facing an inner surface of said illumination window; a light-detecting element which is housed in said case, and which detects fluorescent light generated by the paper sheets, via a detection window; light-shielding means attached to only a part of said illumination window and opaque to the light emitted by said light-emitting element; and an illumination monitor disposed in said case facing said inner surface of said illumination window, which detects the light emitted by said light-emitting element and reflected by said inner surface of said illumination window, said illumination monitor monitoring light in a monitor region that is outside the illumination region on the transportation path, the light-shielding means limiting extent of the monitor region whereby variations in intensity of the light emitted by said light-emitting element are accurately detected.