Citizen Electronics Co., Ltd.

Citizen Watch Company, Ltd.

Citizen Holdings Company, Ltd.

Satoshi Goto

Tatsuro Yamada

Takashi Akiyama

Yuki Nishikawa

Shigehisa Watanabe

Keisuke Sakai

Yuki Ochiai

An LED module according to the present invention includes: a mounting substrate; a first LED group including a plurality of LEDs mounted in a first light-emitting area extending in a first direction on the mounting substrate; a second LED group including a plurality of LEDs mounted in a second light-emitting area located outside the first light-emitting area; a dam material surrounding a periphery of the second light-emitting area; a first fluorescent resin coating the first LED group and causing the first light-emitting area to emit light having a first color temperature; and a second fluorescent resin coating at least the second LED group and causing the second light-emitting area to emit light having a second color temperature higher than the first color temperature, and viscosity of the first fluorescent resin is higher than viscosity of the second fluorescent resin.

LED module

The purpose of the present invention is to provide an LED driving circuit with which it is possible to easily manage the color temperature by adjusting light. An LED driving circuit, characterized in having: a first LED group in which a plurality of first LEDs are serially connected, the first LED group contributing to emission of light having a first color temperature; a second LED group in which a plurality of second LEDs are serially connected, the second LED group contributing to emission of light having a second color temperature; a third LED group in which a plurality of second LEDs are serially connected, the second LED group contributing to emission of light having the second color temperature; and a control unit for switching, in response to an increase in a rectified output voltage, from illumination of only the first LED group to illumination of only the second LED group and then from illumination of only the second LED group to illumination of the second LED group and the third LED group, the number of first LEDs included in the first LED group being less than the number of second LEDs included in the second LED group.

LED driver circuit

Light-emitting diode

The purpose of the present invention is to provide an LED drive circuit that is capable of ameliorating insufficient lighting and improving power utilization efficiency. This LED drive circuit is an LED drive circuit wherein the number of LEDs that are turned on varies in accordance with the voltage of a commercial alternating-current power supply, the LED drive circuit being characterized by having an LED row in which multiple LEDs are connected in series, a current detection resistor for detecting a current that flows in the LED row, a bypass circuit that is connected to an intermediate connection part of the LED row, and a current-limiting circuit that is connected to an end of the LED row, wherein the bypass circuit includes a first current-limiting component, the current-limiting circuit includes a second current-limiting component, the first current-limiting component is controlled on the basis of a voltage across the ends of the current detection resistor or a voltage that is obtained by dividing the voltage across the ends of the current detection resistor, and the second current-limiting component is controlled by the divided voltage that is obtained by dividing the current detection resistor.

LED drive circuit

Growing community of inventors

Yamanashi-ken, Japan

Satoshi Goto