Patent ID: 9137881
Filing Date: 2015-09-15
Classification: H05B,Y02B

Abstract:
1. A discharge lamp lighting apparatus comprising: a discharge lamp having a pair of electrodes formed of tungsten and having projections at distal ends thereof; and a power supply apparatus configured to supply AC power to the discharge lamp to light the discharge lamp, wherein: the power supply apparatus is switchable between a first lighting mode in which rated power is supplied to the discharge lamp and a second lighting mode in which power lower than the rated power is supplied to the discharge lamp, the power supply apparatus is configured to supply AC power having a power waveform in which a low-frequency component has a frequency lower than a basic frequency component, the low-frequency component being in a range from 60 to 1000 Hz and being cyclically inserted into the basic frequency component supplied to the discharge lamp, and the power supply apparatus is configured to control power supplied to the discharge lamp with an average power change ratio of 0.01 to 2.1 W/s in a mode switching period in which the mode is switched from the first lighting mode to the second lighting mode.