Influence of Gas Pressure on Performance of Positive Column of Fluorescent Discharge Lamp with 4mm Diameter

Although a cold cathode fluorescent lamp (CCFL), whose diameter is 4 mm, has been used for the backlighting of liquid crystal displays, it is being replaced by an LED. Thus, the CCFL seems to be vanishing from the backlighting field. However the CCFL has an excellent long life performance. If the CCFL could have a higher output on a par with the linear fluorescent lamp used in the general lighting whose diameter is 25 mm (FHF lamp), it would be possible to replace the FHF lamp with it because of its long lifetime and its easy control of the light distribution. We investigated the influence of the gas pressure on the performance of the positive column of a discharge lamp with a 4 mm diameter, and found that the electron temperature of this lamp is lower than that of a fluorescent lamp with a 25 mm diameter and that the higher electron temperature by decreasing the gas pressure could increase the lumen output and the efficiency of the positive column of the discharge lamp with the 4 mm diameter.