| US 7,479,743 B2 | ||
| Vehicle lighting apparatus | ||
| Takanori Namba, Shizuoka (Japan); and Masayasu Ito, Shizuoka (Japan) | ||
| Assigned to Koito Manufacturing Co., Ltd., Tokyo (Japan) | ||
| Filed on Dec. 11, 2006, as Appl. No. 11/636,915. | ||
| Claims priority of application No. 2005-357491 (JP), filed on Dec. 12, 2005. | ||
| Prior Publication US 2007/0132407 A1, Jun. 14, 2007 | ||
| Int. Cl. H05B 37/02 (2006.01); H05B 39/04 (2006.01); H05B 41/36 (2006.01); H05B 37/00 (2006.01); H05B 41/16 (2006.01); G05F 1/00 (2006.01) | ||
| U.S. Cl. 315—307 [315/291; 315/224; 315/209 R; 315/312; 315/247] | 6 Claims |
| 1. A vehicle lighting apparatus comprising:
a plurality of semiconductor light sources that are connected with each other in series;
a switching regulator for supplying an electric power from a power source to each of said plurality of semiconductor light
sources;
forward voltage detection means for detecting a forward voltage of each of said plurality of semiconductor light sources;
and
failure detection means for detecting the failure of each of said semiconductor light sources based on the detected value
of said forward voltage detection means;
wherein a semiconductor light source having a lower forward voltage is connected closer to a reference potential side of said
power source among said plurality of semiconductor light sources.
|