| 摘要 |
PURPOSE:To provide a light-emitting electron tube of a compact size from which yellow monochromatic light of vary high efficiency can be obtained. CONSTITUTION:A light-emitting electron tube consists of a cylindrical inner tube (N) forming an airtight space and a heat-insulating outer tube (G) covering the inner tube (N). The inner and the outer tubes (N) and (G) are formed by a material which can efficiently transmit sodium D rays (the two spactra of 589nm and 590nm) such as transparent glass. In the inner tube (N), a pair of cathodes (K1) and (K2) are installed at least one of which consists of an electron-emitting cathode. The anode (A) is installed almost in the middle between the cathodes (K1) and (K2) and has a mesh- or grid-like shape. The inner tube (N) is charged with sodium vapor and the outer tube (G) is vacuum. From a d.c. power source (DC), positive d.c. voltages are respectively applied across the anode (A) and the cathode (K1) and across the anode (A) and the cathode (K2) through a resistance (R). According to such a light-emitting electron tube, yellow monochromatic emission of very high efficiency, or light emitted from sodium vapor of the lowest excitation level and having a spectral luminous efficiency of 589-590nm near the maximum visible wavelength of 555nm, can be obtained. |
