抄録
The characteristics of hot cathode fluorescent lamps in low current regions (10∼40mA) were investigated by experiments and numerical analysis. A quantitative correlation between the cathode fall voltage and the lifetime was obtained. If the cathode fall voltage is less than or equal to 14V, arc discharge can be maintained stably during the lifetime, and hence, the life reliability of lamps can be improved. In order to reduce the cathode fall voltage for a given lamp current, it is effective to increase Ar gas pressure, and to decrease the surface area of the coils. The cold spot temperature is not effective to reduce the cathode fall voltage in the range of 10 to 60°C. The relation between the lamp design parameters and the cathode fall voltage was analyzed numerically on the basis of a modified theoretical model. The calculated results support the experimental results.
