| 摘要 |
PROBLEM TO BE SOLVED: To light a lamp without causing a problem such as a loss of an electrode in either case of arranging the lamp vertically or horizontally. SOLUTION: The lamp 10 is illuminated by supplying an AC current from a power feeding device 20 to the high-pressure discharge lamp 10 and inserting a low frequency into a steady lighting frequency at a predetermined period. An arrangement of the lamp 10 is detected by, for example, a detection circuit 30, and, when the lamp is horizontally arranged, a control part 50 illuminates the lamp by making an electric energy flowing from an other electrode of the lamp 10 to one electrode substantially equal to the electric energy flowing from the one electrode to the other electrode. When the lamp is vertically arranged, at least when it is illuminated at the low frequency, the lamp is illuminated by making the electric energy flowing from the electrode arranged upstream to the electrode arranged downstream, smaller than the electric energy flowing from the electrode arranged downstream to the electrode arranged upstream. COPYRIGHT: (C)2011,JPO&INPIT |
