| 摘要 |
PURPOSE:To provide an ultraviolet ray generation device having the capability of preventing a drop in ultraviolet ray intensity occurring upon an increase in wall tube load, and improving an ultraviolet ray maintenance factor. CONSTITUTION:This device is equipped with a low pressure mercury vapor discharge lamp 1 comprising quartz glass containing sealed mercury and rare gas, and a lighting device 10 having input power of 0.3W/cm<2> or more per unit inner surface area of a luminous section, and supplying rectangular wave current of a frequency equal to or higher than 5kHz. According to this construction, the rectangular wave current having input power of 0.3W/cm<2> or more per unit inner surface area is used to light the tube 1 and, therefore, the tube 1 can be filled with excited atoms without any need to increase mercury vapor pressure to such an extent as in the case of a sine wave current. Also, ultraviolet ray intensity does not drop, even when a wall tube load increases. In addition, current having a frequency of 5kHz or higher is supplied, and an anode arrests electrons thereabout before dispersion over a tube wall, thereby causing a decrease in anode drop voltage. Thus, the anode is less subjected to the impact of electrons and the scattering of electrons is reduced, thereby enabling the remarkable drop of a light flux maintenance factor to be prevented. |
