| US 7,541,748 B2 | ||
| Discharge lamp lighting device | ||
| Fumio Haruna, Yokohama (Japan); Masaru Shimizu, Kamakura (Japan); Kouji Kitou, Hiratsuka (Japan); and Tetsunosuke Nakamura, Yokohama (Japan) | ||
| Assigned to Hitachi, Ltd., Tokyo (Japan); and Hitachi Media Electronics Co., Ltd., Mizusawa (Japan) | ||
| Filed on Oct. 11, 2005, as Appl. No. 11/248,785. | ||
| Application 11/248785 is a continuation of application No. 10/888241, filed on Jul. 08, 2004, granted, now 6,995,523. | ||
| Claims priority of application No. 2004-050740 (JP), filed on Feb. 26, 2004. | ||
| Prior Publication US 2006/0028153 A1, Feb. 09, 2006 | ||
| Int. Cl. H05B 37/02 (2006.01) | ||
| U.S. Cl. 315—291 [315/300; 315/302; 315/307] | 3 Claims |
| 1. A discharge lamp lighting device, comprising:
a power control circuit which controls a power to drive a discharge lamp;
a voltage detector which detects an output voltage of the power control circuit;
a current detector which detects a current supplied to the discharge lamp;
a bi-directional communication unit which communicates an exterior of the discharge lamp lighting device via a bi-directional
communication; and
a processing circuit which controls the power control circuit in accordance with a detection result of the voltage detector,
a detection result of the current detector and a required command received by the bi-directional communication,
wherein the processing circuit changes a driving status of the power control circuit from a stationary driving state driven
in a normal power to a low power driving state over 0.5 seconds, the low power driving state in which the power being lower
than a power in the stationary driving state and through which the driving status of the power control circuit moves from
the stationary driving state to a turn-off state.
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