Patent attributes
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.
