Patent ID: 9380686
Filing Date: 2016-06-28
CPC Classification: G03B,H05B,Y02B

Claim Text:
1. A discharge lamp lighting apparatus comprising: an electric supply circuit (Ux) which causes a discharge lamp (Ld) to maintain electric discharge, and supplying predetermined electric power thereto; an inverter (Ui) for carrying out polarity reversal of output voltage of the electric supply circuit (Ux) which is applied to the discharge lamp (Ld); and an inverter control circuit (Uf) which receives a polarity reversal notification signal (So) to be inputted from an outside in order to give a notice of polarity-reversal timing (h wherein the inverter control circuit (Uf) has a polarity-reversal control circuit (Ufc) which manages a polarity-reversal operation of the inverter (Ui) based on the polarity reversal notification signal (So), and an inverter polarity phase generation circuit (Ufp) which generates the inverter polarity phase signal (Sf wherein the polarity-reversal control circuit (Ufc) gives a polarity-reversal order signal (Sr) to the inverter polarity phase generation circuit (Ufp), as a basic operation, every time the polarity-reversal control circuit (Ufc) recognizes polarity-reversal timing (h 0 , h 1 , h 2 , . . . ), which is notified by the polarity reversal notification signal (So), so that the polarity of the inverter (Ui) is inverted, and wherein the polarity-reversal control circuit (Ufc) counts the number of times of consecutive appearances Np of a normal polarity-reversal interval period (Tn