| 摘要 |
PROBLEM TO BE SOLVED: To emit the light at the even brightness along the whole periphery of a lamp, regardless of the temperature distribution at the lamp periphery. SOLUTION: When a high-frequency current is let flow to a coil 2 from a high-frequency power source, a discharge tube 1 is lighted, and the water flow 100 around the discharge tube 1 is irradiated with the ultraviolet rays. Since the temperature of the upstream part TL of the discharge tube 1 is made lower than the other parts, in this case, the radiating amount of the ultraviolet- rays at the part TL of the discharge tube 1 is reduced, by leaving as it is, and the radiation of the ultraviolet-rays to the water flow 100 is mottled, but a capacitor C is connected to the coil part corresponding to the part TL, so as to make the current at this coil part different from the other parts, and the radiating amount of the ultraviolet-rays at this part is increased as the part of dropping the radiating amount of the ultraviolet-rays. Consequently, an even radiating amount of the ultraviolet-rays can be obtained along the whole area in the longitudinal direction of the discharge tube 1, and the water flow 100 can be sterilized evenly. |
