| 摘要 |
An external electrode lamp (2) includes a glass discharge container (4) having a discharge medium enclosed therein, and first and second external electrodes (6 and 8) provided external to the discharge container. Since the surface area of the first external electrode is larger than that of the second external electrode, the capacitance of a first capacitor constituted from the first external electrode and a first dielectric part including a portion of the discharge container between the first external electrode and the discharge medium is larger than that of a second capacitor constituted from the second external electrode and a portion of the discharge container between the second external electrode and the discharge medium. Consequently, when a high-voltage output of a lighting circuit is connected to the first external electrode, the second external electrode is grounded, and a voltage is applied, the voltage-to-ground at a portion of the inner wall of the discharge container that faces the first external electrode is higher than conventional, which facilitates starting discharges, thus improving the in-dark starting characteristic.
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