PHOTODETECTING TUBE

PURPOSE:To increase the incident quantity of a detection light and to improve the detection sensitivity, etc., by sticking a grounded transparent conductive film and a glass surface plate with a dielectric film to other glass surface by using an optical binder. CONSTITUTION:To a photoelectric converting film 3, a focusing electrode 4, a photoelectric multiplying part 5, etc., a high voltage divided by resistances R1-Rn is applied, and focusing and multiplication of an electron beam are execut ed thereby. Subsequently, it reaches an earth through a transparent film 7 containing a conductive film on the outside surface of a transparent photodetecting plate 2, therefore, it does not occur that the photodetecting surface has static electricity. Accordingly, dust, etc., in the air come not to adhere. Also, by providing a reflection reducing film, as well, what is called a Fresnel reflection decreased, and the sensitivity is more improved.