Joerg Hinrich Fechner

Glass tube of high dielectric constant and low dielectric loss for external electrode fluorescent lamps

A glass tube of aluminosilicate glass, with high dielectric constant K∼6.0 and low dielectric loss tan δ∼8.0×10−4, was investigated for the external electrode fluorescent lamps (EEFLs) of a dielectric barrier discharge. Compared with conventional EEFLs made out of borosilicate glass tubes with K∼(4.9−5.3) and tan δ∼(2.3−2.4)×10−3, the efficiency of the aluminosilicate EEFL increases by 15%−25% even at high luminance above 20 000 cd/m2 and the pinhole stability of the aluminosilicate EEFL also improves remarkably. In a soda-lime glass EEFL with a high dielectric loss tan δ∼7.0×10−3, the luminance and pinhole stability deteriorate even with a high dielectric constant K∼7.2 at room temperature, because the value of tan δ escalates as the temperature on the external electrode increases due to the dielectric heat dissipation.

P-63: Distinguished Student Poster: Effects of Glass Capacitance on the Performance of External Electrode Fluorescent Lamps

The efficiency of EEFLs with the new glass tube of high dielectric constant K∼6.6 and low dielectric loss tan δ, reaches 45 lm/W which is ∼ 20 % higher than 38 lm/W in the conventional glasses of K ∼ 5.5. And this new glass tube EEFL also shows a high reliability against pinholes.

P-100: Dielectric Property and Hg-Consumption with Glass Tubes of External Electrode Fluorescent Lamp

External electrode fluorescent lamps of aluminosilicate glass with high dielectric constant, a low dielectric loss and a lowest sodium composition were compared with the conventional EEFLs of borosilicate and soda-lime glasses. The luminance efficiency increases by 15∼25 %, the pinhole stability improves remarkably, and the blackening of Hg-consumption is not observed.