公开(公告)号：US11528787B2

公开(公告)日：2022-12-13

申请号：US16895175

申请日：2020-06-08

申请人： SAMSUNG ELECTRONICS CO., LTD.

发明人： Deokhee Han ,  Hyunjung Kim

IPC分类号： H05B45/24 ,  H05B47/21 ,  F21S4/26 ,  F21Y115/10

摘要： A light-emitting circuit includes first and second light-emitting element strings respectively configured to emit light having a first and second color temperatures; a rectifying circuit configured to rectify a voltage, input by an alternating current (AC) power source, to generate a driving voltage; a string switching circuit configured to select at least one light-emitting element string to be used for light emission from among the first light-emitting element string and the second light-emitting element string; an off/on sensing circuit configured to change a selection of the string switching circuit to change a color temperature of light, which is emitted by the light-emitting circuit, when the AC power source is turned off and then turned on; and a driving circuit configured to turn on, in turn, light-emitting elements in the selected at least one light-emitting element string, according to a change in the driving voltage over time.