Citizen Watch Company, Ltd.

Citizen Electronics Co., Ltd.

Takahiro Hori

Tatsuro Yamada

Yasuaki Kayanuma

Yu Kayanuma

Kenichi Kikuchi

Light emitting diode

An LED module includes, on a circuit board, first to fourth electrodes, a first circuit including a first LED group, and a second circuit including second and third LED groups, a switch element and a detection element. The second circuit includes a first path leading from the second LED group to one end of the detection element, and a second path leading from the third LED group via the switch element to one end of the detection element. The first and second electrodes are connected to the first circuit, the third electrode is connected to the second and third LED groups, and the fourth electrode is connected to the other end of the detection element. The threshold voltage for light emission of the second LED group is larger than that of the third LED group. The switch element controls a current flowing through the second path in accordance with a current flowing via the detection element.

Growing community of inventors

Yamanashi, Japan

Takahiro Hori