| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device that can make realization between entire light lighting and deep light control by using a PWM light control method and is improved to be able to make continuous light control by switching an alternating-current output voltage of an inverter circuit between high and low levels. <P>SOLUTION: The discharge lamp lighting device is provided with an inverter circuit INV whose input terminal is connected with a direct-current power supply RDC and can cause an alternating-current output voltage thereof to be switched between at least two stages of low and high, and provided with control means CC for controlling the inverter circuit so as to be able to perform light control operations including: a first light control operation mode having one cycle of PWM control, composed of a first time period in which the alternating-current output voltage of the inverter circuit is high and a second time period in which the same is low, with their duties being relatively varied to controlledly light a discharge lamp DL; and a second light control operation mode having one cycle of PWM control, composed of the second time period and a third time period for substantially no output, with their duties being relatively varied to controlledly light the discharge lamp. <P>COPYRIGHT: (C)2009,JPO&INPIT |
