A Part4 Extensive ReadingImage dissector and Orthicon The image dissector(分析者) was invented by Philo Farnsworth, one of the pioneers of electronic television, in 1927. It is a type of cathode (ai)ray tube occasionally employed as a camera in industrial television systems. The image dissector had very poor light sensitivity, and was useful only where scene illumination( BF) exceeded 685 cd/m2, but it was ideal for high light levels such as when engineers wanted to monitor the bright, hot interior( apof an industrial furnace. Owing to its lack of sensitivity, the image dissector was rarely used in TV broadcasting, except to scan film and other transparencies. It was, however, the beginning of the electronic TV age. The image dissector sees the outside world through a glass lens, which focuses an image through the clear glass wall of the tube onto a special plate which is coated with a layer of caesium oxide( 1648). When light strikes caesium oxide, the material em its electrons somewhat like a mirror that reflects an image made of electrons rather than light. These electrons are aimed and accelerated by electric and magnetic fields onto the dissector's single electron 2021210k2021/2/20 P.10 Image dissector and Orthicon The image dissector(分析者) was invented by Philo Farnsworth, one of the pioneers of electronic television, in 1927. It is a type of cathode (负极 ) ray tube occasionally employed as a camera in industrial television systems. The image dissector had very poor light sensitivity, and was useful only where scene illumination(照明) exceeded 685 cd/m2, but it was ideal for high light levels such as when engineers wanted to monitor the bright, hot interior(内部)of an industrial furnace. Owing to its lack of sensitivity, the image dissector was rarely used in TV broadcasting, except to scan film and other transparencies. It was, however, the beginning of the electronic TV age. The image dissector sees the outside world through a glass lens, which focuses an image through the clear glass wall of the tube onto a special plate which is coated with a layer of caesium oxide(氧 化铯). When light strikes caesium oxide, the material emits electrons, somewhat like a mirror that reflects an image made of electrons, rather than light. These electrons are aimed and accelerated by electric and magnetic fields onto the dissector's single electron & Part4 Extensive Reading