US 7,557,523 B2
Discharge lamp lighting device, and lighting equipment and lighting system using the device
Takeshi Goriki, Kyoto (Japan); Koji Noro, Osaka (Japan); Noriyuki Fukumori, Kyoto (Japan); and Kenichi Fukuda, Osaka (Japan)
Assigned to Panasonic Electric Works Co., Ltd., Osaka (Japan)
Appl. No. 11/577,891
PCT Filed Sep. 16, 2005, PCT No. PCT/JP2005/017167
§ 371(c)(1), (2), (4) Date Jun. 28, 2007,
PCT Pub. No. WO2006/046364, PCT Pub. Date May 04, 2006.
Claims priority of application No. 2004-311499 (JP), filed on Oct. 26, 2004.
Prior Publication US 2008/0030143 A1, Feb. 07, 2008
Int. Cl. H05B 41/36 (2006.01)
U.S. Cl. 315—308  [315/291; 315/360; 315/224; 315/209 R; 324/677; 324/679; 320/166] 13 Claims
OG exemplary drawing
 
1. A discharge lamp lighting device, comprising:
a DC power source circuit;
a smoothing capacitor connected to an output end of the DC power source circuit;
an inverter main circuit adapted to convert a DC power output from the smoothing capacitor, to an AC power, and supply the AC power to a discharge lamp;
a main control circuit adapted to control the inverter main circuit so as to control the AC power to be supplied to the discharge lamp;
a timer circuit adapted to count a predetermined time;
a power supply suppression section adapted to voluntarily suppress power supplied to the smoothing capacitor during a period where the timer circuit counts the predetermined time in an ON state of the discharge lamp;
a voltage/voltage drop detection section adapted to detect a voltage or a voltage drop of the smoothing capacitor at least during a period where the power supplied to the smoothing capacitor is suppressed;
a first comparator adapted to compare between a detection value of the voltage or the voltage drop of the smoothing capacitor and a first threshold value to determine a life end of the discharge lamp, and output a result of the determination; and
an auxiliary control circuit adapted to perform a control operation depending on the output of the first comparator.