| 摘要 |
PROBLEM TO BE SOLVED: To optimize the filament current, while down-sizing and standardizing a lighting device, and to add various functions related to the output to a filament in an appropriate mode, in a discharge lamp lighting device for lighting a low voltage discharge lamp having a pair of thermal cathode filaments.SOLUTION: A discharge lamp lighting device (1) includes a first power supply circuit (2) for supplying a low voltage discharge lamp (5) with a lamp voltage or current, a second power supply circuit (3) having an insulated DC/DC converter (30) for supplying first and second filaments (51, 52), respectively, with first and second DC filament currents, converted from a DC voltage inputted from a part of first power supply circuit, and first and second current detection circuits (31, 33) for detecting the first and second filament currents, respectively, and a control section (4) for controlling the DC/DC converter so that the first current detection value matches a target value, and stopping the output operation of the DC/DC converter when the second current detection value deviates from a predetermined range.SELECTED DRAWING: Figure 1 |
