Mercury-Free Lamp and Lamp Apparatus

摘要

A mercury-free lamp including: a glass bulb ( 4 ) that is filled with a rare gas; a first internal electrode unit ( 19 ) and a second internal electrode unit ( 15 ) that are provided in the glass bulb ( 4 ); and an external electrode ( 24 ) that is provided on an outer surface of the glass bulb ( 4 ) in an area that corresponds to a discharge path, which is formed during lighting between the first internal electrode unit ( 19 ) and the second internal electrode unit ( 15 ), such that a positive column is generated along the discharge path and is expanded in transverse sectional area by the external electrode. The first internal electrode unit ( 19 ) is composed of internal electrodes ( 18 ) and ( 20 ), and the second internal electrode unit ( 15 ) is composed of internal electrodes ( 14 ) and ( 16 ).