| 摘要 |
PURPOSE:To perform a stable and reliable detecting, by a method wherein a device has an exciting light source, which radiates an exciting light on an object to be detected being conveyed, and a photoelectric converter positioned at a given distance in a position corresponding to a given region. CONSTITUTION:A detector for a luminous material is provided with an exciting light source 2 for radiating an exciting light on an object P to be detected, such as mails, and a photoelectric converters 11 and 12 located at a given distance in a direction at right angles to the conveying direction of the mail P in a position corresponding to a specified region, where a stamp is sticked, on the mail P. This constitution brings an output signal level to an absolute value ''5'' when corresponding to a stamp K, and to an absolute value ''1'' when corresponding to the surface of the mail P. Namely, an S/N can be increased to 5:1, and this enables to perform a stable and reliable detection. |
