| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device and an illuminating device using it, which can detect the end of life of a discharge lamp even in the case of changing a dimming level, and minimize the malfunction of a protective means. <P>SOLUTION: A discharge lamp lighting device A comprises: an inverter circuit 1 for transforming a direct-current voltage into a high-frequency voltage; a resonance circuit 2 connected between outputs of the inverter circuit 1 for lighting a discharge lamp FL by resonant effects; a control circuit 4 for controlling operations of the inverter circuit 1; a dimmer section 8 for continuously changing an output voltage to the discharge lamp FL by changing an operating frequency of the inverter circuit 1; a direct-current component detecting section 7 and a voltage comparator EL, which detect whether the discharge lamp FL is in a stage of ending of life for each predetermined time, and then output a life-ending detecting signal if the stage of ending of life is detected; and a frequency control circuit 5 and a driving circuit 6, which control switching elements Q1, Q2 to reduce or stop outputting to the discharge lamp FL if the life-ending detecting signal is inputted thereto from the voltage comparator EL. <P>COPYRIGHT: (C)2010,JPO&INPIT |
